Arq Bras Cardiol abc Arquivos Brasileiros de Cardiologia Arq. Bras. Cardiol. 0066-782X 1678-4170 Sociedade Brasileira de Cardiologia - SBC KYZsgNc4Fn4VPXFbC9m8StQ S0066-782X2026000200602 00602 10.36660/abc.20250145 Artigo Original Registro de Intervenções Coronárias em Vasos de Muito Pequeno Calibre: Análise de Stent Eluidor de Sirolimus e Outros Stents Contemporâneos 0000-0003-4198-2621 Slaviero João Vitor Concepção e desenho da pesquisa Obtenção de dados Análise e interpretação dos dados Análise estatística e Obtenção de financiamento Redação do manuscrito 1 Manica André Luiz Langer Concepção e desenho da pesquisa Redação do manuscrito Revisão crítica do manuscrito quanto ao conteúdo 1 0000-0002-9674-8528 Leite Rogério Eduardo Gomes Sarmento Concepção e desenho da pesquisa Análise e interpretação dos dados 1 0009-0002-3237-0199 Borsa Eduarda Paiva Obtenção de dados 2 0000-0003-2823-5365 Schmidt Marcia Moura 1 0009-0001-3986-4848 Ogando Rodrigo Campos Obtenção de dados 3 Teixeira Julia Kurtz Concepção e desenho da pesquisa Obtenção de dados 1 0000-0002-7883-828X Guimarães Raphael Boesche 1 Azmus Alexandre Damiani Concepção e desenho da pesquisa Análise e interpretação dos dados Redação do manuscrito Revisão crítica do manuscrito quanto ao conteúdo 1 Gottschall Carlos A. M. conteúdo Revisão crítica do manuscrito quanto ao 1 Instituto de Cardiologia Porto Alegre RS Brasil Instituto de Cardiologia, Porto Alegre, RS – Brasil Universidade Federal de Ciências da Saúde de Porto Alegre Porto Alegre RS Brasil Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS – Brasil Pontifícia Universidade Católica do Rio Grande do Sul Porto Alegre RS Brasil Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS – Brasil João Vitor Slaviero • Instituto de Cardiologia – Avenida Princesa Isabel, 395. CEP 90040-371, Porto Alegre, RS – Brasil. E-mail: slavierojv@gmail.com

Henrique Ribeiro

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A intervenção coronária percutânea (ICP) de vasos de muito pequeno calibre (≤ 2,25mm) é um desafio técnico e tem piores resultados quando comparado aos maiores calibres. O stent Inspiron® é um stent farmacológico (SF) feito no Brasil, o qual têm segurança e eficácia avaliadas por diversos estudos em diferentes cenários, mas não há dados analisando seu desempenho em vasos <2,5mm.

 Objetivos

Analisar os resultados clínicos de ICP com SF’s em vasos de muito pequeno calibre e comparar com outras plataformas de SF’s contemporâneos. O desfecho MACE foi definido como por mortalidade cardíaca, infarto da lesão alvo e revascularização de lesão alvo clinicamente dirigida.

 Métodos

Estudo observacional, com amostra consecutiva em centro de referência no Brasil, entre 2017 e 2021, tendo desfechos analisados nos períodos intra-hospitalar, 30 dias, seis e 12 meses, com nível de significância estatística de 5%.

 Resultados

Um total de 783 SF’s foram implantados, sendo 47% INSPIRON® e 46,8% “Outros SF’s”. A idade média dos pacientes foi de 64,7±11 anos, 61% dos pacientes masculinos e 42% portadores de Diabetes Mellitus. Aos 12 meses, o desfecho de MACE geral foi 4,54% (36/793) e foi similar entre os grupos comparados (Inspiron®-4,6%; vs.. “Outros SF’s” -4,6%; p=1,000), sem diferença significativa nos desfechos individuais. A taxa de trombose de stent foi similar entre os grupos (4 [1,0%] vs. 2 [0,5%], p 0,868).

 Conclusão

Nossos achados demonstram resultados aceitáveis e com desempenho similar em 12 meses do Inspiron® a outros SF’s contemporâneos em vasos de muito pequeno calibre.

Registro de Intervenções Coronárias em Vasos de Muito Pequeno Calibre: Análise de Stent Eluidor de Sirolimus e Outros Stents Contemporâneos RLA: Revascularização de lesão alvo; Mortalidade Cardíaca: Mortalidade cardíaca confirmada e provável; MACE: mortalidade cardíaca, infarto da lesão alvo e revascularização de lesão alvo clinicamente dirigida.

Palavras-chave Stents Farmacológicos Sirolimo Intervenção Coronária Percutânea Doença da Artéria Coronariana Fontes de financiamento:O presente estudo não teve fontes de financiamento externas. Introducão

A intervenção coronária percutânea (ICP) vem aumentando sua complexidade como consequência da melhora na tecnologia dos materiais, da expertise dos operadores e das técnicas dos procedimentos.1,2 Nos pacientes submetidos a ICP, a prevalência de doença de pequenos vasos (<2,75mm) tem sido relatada em até 50% dos casos.3-5 Com a subsequente disponibilidade de stents de 2,0 e 2,25 mm, o termo “vaso de muito pequeno calibre” foi proposto.6

A ICP de vasos de pequeno calibre constitui um desafio estando associada a maior risco de eventos cardíacos, incluindo reestenose e trombose de stent.4,7-16 Ademais, estas características anatômicas geralmente acompanham um padrão de doença coronariana aterosclerótica difusa, necessitando stents de maiores comprimentos, que apresenta relação direta com o risco de reestenose,13 além de ser características que desfavorecem o tratamento cirúrgico alternativo.14-16

Visto o grande número de opções de stent farmacológico (SF’s) disponíveis atualmente, se buscou identificar características que pudessem predizer melhores resultados. Visto que a menor espessura das hastes, pode estar associada a menor trombogenicidade e menor tensão de cisalhamento,17-19 dados de metanálise comparando espessuras de hastes de SF’s contemporâneos demonstram menores riscos relativos de desenvolvimento de trombose de stent, infarto e revascularização de lesão alvo em SF de hastes menores, mas sem significância estatística. Outra característica explorada foi o fármaco utilizado nos SF’s. A utilização de SF’s parece ter um efeito de classe quanto ao desempenho em vasos de pequeno calibre,20 embora em contexto de lesões mais longas os dados de revascularização de lesão alvo e infarto tendem a ser melhores quando utilizados SF’s eluídos com Sirolimus.21

O stent INSPIRON® foi o primeiro SF produzido no Brasil e é eluidor de Sirolimus, com liga de cobalto-cromo e haste de 75 μm de espessura, polímero abluminal biodegradável, apresentando a possibilidade de implante em vasos de muito pequeno calibre. Vários estudos clínicos testaram sua segurança e eficácia,17,18,22 mas não há dados clínicos comparando seu desempenho em vasos de calibre ≤2,25mm com outros SF contemporâneos.

Visto o grande número de ICP’s nestes diâmetros e o uso amplamente difundido do Inspiron®, nosso objetivo é analisar os resultados de mundo real de ICP’s com SF’s contemporâneos em vasos de muito pequeno calibre.

 Métodos Desenho do estudo, local e população

Estudo observacional, prospectivo, por iniciativa de autores, com uma amostra consecutiva de pacientes acima de 18 anos encaminhados ao laboratório de hemodinâmica de hospital terciário de referência no Sul do Brasil, entre 2017 e 2021, com indicação e submetidos a ICP de vasos de muito pequeno calibre com INSPIRON® ou outros SF’s contemporâneos. A indicação da intervenção ficou a critério da equipe assistente responsável pelo caso. Não foram incluídos pacientes com stents implantados em lesões coronárias de outros calibres (≥2,5mm) e ICP sem implante de SF’s.

Os dados foram registrados, sendo a coleta feita a partir da revisão de prontuário, consultas presenciais e contato telefônico. Foram coletados os desfechos clínicos intra-hospitalares, em 30 (trinta) dias, seis (06) meses e em 12 (doze) meses. Novas cineangiocoronariografias foram realizadas apenas em pacientes com indicação clínica de estratificação invasiva pela equipe assistente, não sendo realizadas rotineiramente durante o seguimento, assim como testes funcionais.

O presente estudo foi aprovado pelo Comitê Institucional de Pesquisa e Ética da instituição, estando em conformidade com a Resolução CNS 466/2012.

 Aspectos do procedimento

Todos os pacientes realizaram a ICP recebendo ou sendo administrado imediatamente após, dupla antiagregação plaquetária, e heparina não fracionada durante o procedimento. A estratégia técnica do procedimento, o tipo e a duração da terapia antiplaquetária dupla foram definidos pela equipe assistente. Com exceção dos casos que utilizaram imagem intravascular, as demais ICP’s utilizaram a estimativa angiográfica visual para determinação do diâmetro de referência do vaso.

 Stents

Todos os pacientes incluídos receberam pelo menos um SF INSPIRON® e/ou outro(s) SF’s. A decisão de implantar o tipo de stent foi baseada no critério do operador e na disponibilidade momentânea no centro médico. As características dos stents utilizados são apresentadas na Tabela 1.

– Stents utilizados
Stent N (%) Material Espessura Droga Polímero
Inspiron ® 392 (50,1%) Cromo-Cobalto 75μm Sirolimus Biodegradável
Resolute Onyx/ Integrity ® 218 (27,8%) Cromo- Cobalto 81/91μm Zotarolimus Durável
Promus ® 73 (9,7%) Cromo-Platina 81μm Everolimus Biodegradável
Xience ® 37 (4,7%) Cromo- Cobalto 81μm Everolimus Durável
Synergy ® 30 (3,8%) Cromo-Platina 74μm Everolimus Biodegradável
Orsiro ® 19 (2,4%) Cromo- Cobalto 60μm Sirolimus Biodegradável
Ultimaster ® 8 (1,0%) Cromo- Cobalto 80μm Sirolimus Biodegradável
Supraflex ® 6 (0,8%) Cromo- Cobalto 60 Sirolimus Biodegradável

Tabela referente a stents farmacológicos analisados na amostra, apresentados em ordem de frequência, material de sua haste metálica, espessura de haste metálica, droga eluidora e polímero utilizado.

 Definição de objetivos e desfechos

O desfecho principal MACE (Major Adverse Cardiovascular Events) foi composto por “Mortalidade Cardíaca”, “Infarto da Lesão Alvo” e “Revascularização de Lesão Alvo Clinicamente Dirigida”. Ademais, foram analisados os componentes individuais do desfecho principal, assim como o desfecho de “Trombose de Stent”, o qual foi definido como infarto agudo do miocárdio associado a oclusão do SF’s 2,00 ou 2,25mm previamente implantando, o que é classificado como “Trombose de stent definida ou confirmada”.20

O objetivo do estudo foi analisar o desfecho composto geral da amostra e compará-lo entre os stents INSPIRON® e outros SF’s contemporâneos disponíveis no centro durante o seguimento de um ano. Foi comparada a diferença nas taxas de MACE entre diferentes espessuras de haste (<80μm vs. >80 μm), o tipo de droga eluída (sirolimus vs. outras drogas).

O sucesso angiográfico da ICP foi definido como uma lesão residual mínima do diâmetro da estenose de <20%, com fluxo TIMI III, sem oclusão de ramo lateral, sem dissecção com comprometimento do fluxo coronário anterógrado, embolização distal ou trombo angiográfico.21

 Análise estatística

A análise dos dados foi realizada no sistema IBM Statistical Package for the Social Sciences (versão 20.0). Os dados categóricos são apresentados como números (n) e porcentagens (%). As variáveis contínuas são apresentadas como média ± desvio padrão. A normalidade da distribuição de cada variável contínua foi avaliada pelo teste de Kolmogorov-Smirnov. A associação entre variáveis categóricas foi realizada através do teste de Qui-quadrado e se testaram diferenças estatisticamente significativas entre variáveis contínuas pelo teste T de Student não pareado, todos com um nível de significância bilateral de 0,05. As curvas de sobrevida foram estimadas pelo método de Kaplan-Meier, e as diferenças entre os grupos foram comparadas por meio do teste log-rank, adotando-se um nível de significância de 5%.

 Poder do estudo

Com a amostra disponível para realizar o estudo, 391 e 392 pacientes nos grupos avaliados, conseguimos detectar diferenças de aproximadamente 6 pontos percentuais com um poder acima de 80%. Estes cálculos foram realizados através do programa WINPEPI 11.65.

 Resultados

De janeiro de 2017 a dezembro de 2021, 834 stents foram implantados e incluídos no banco de dados, dos quais 783 (93,8%) stents foram implantados com sucesso, preencheram os critérios de inclusão e tiveram seguimento por pelo menos 12 meses, sendo 392 stents INSPIRON® (47%) e 391 “Outros SF’s” (46,8%). Esses 834 stents foram implantados em 762 pacientes (1,03 stent por paciente). Sete stents (0,8%) não foram incluídos no seguimento (quatro no grupo INSPIRON® e três no grupo “Outros SF’s”, 1,02% vs. 0,76%, p 0,760) devido a quatro eventos de no-reflow, duas falhas na entrega dos stents devido a tortuosidade e calcificação severas proximais as lesões, e um óbito por fibrilação ventricular durante a liberação do stent (Figura 1).

– Fluxograma.

As taxas de hipertensão, diabetes mellitus, tabagismo ativo e dislipidemia foram semelhantes entre os grupos. A média de idade foi maior no grupo “Outros SF’s” com significância estatística, embora a pequena diferença numérica não tenha uma relevância no impacto clínico dos desfechos. O diagnóstico prévio de insuficiência cardíaca foi maior no grupo “INSPIRON®” e a apresentação clínica que motivou a ICP foi por síndrome coronariana aguda em 74,7% das intervenções, das quais o diagnóstico mais frequente foi de angina instável (40,4%), tendo taxa significativamente maior no grupo “Outros SF’s”. Demais informações clinicas são apresentadas na Tabela 2.

– Características clínicas e demográficas
Características Clínicas e Demográficas Stents (n = 783) INSPIRON® (n = 392; 50%*) Outros SF (n = 391; 50%*) p
Idade em anos 64,7 63,3 ±10,98 66,13±11,15 0,001
IMC kg/ m2 27,5 27,26 ±3,55 27,64 ±3,73 0,138
Masculino 480(61,3%) 227(47,2%) 253(52,8%) 0,060
Creatinina (g/dL) 1,04 1,02 ±0,38 1,06±0,40 0,249
HAS 603(77%) 302 (50%) 301 (50%) 1,000
Histórico Familiar de DAC 69 (8,8%) 37 (59,6%) 32 (46,4%) 0,622
Tabagista ativo 293(37,4%) 156 (53,3%) 137 (46,7%) 0,193
DM 329 (42%) 177(53,7%) 152 (46,3%) 0,088
DM em uso de insulina 92 (11,7%) 55 (59,7%) 37(40,3%) 0,091
Dislipidemia 259(33,1%) 121 (46,7%) 138 (53,3%) 0,105
IC – FEVE <50% 48 (6,1%) 33 (68,7%) 15 (31,3%) 0,012
AVE prévio 27 (3,4%) 15 (55,5%) 12 (44,5%) 0,700
Infarto do Miocárdio prévio 121(15,5%) 64 (52,8%) 57(47,2%) 0,563
ICP prévia 162(20,7%) 73 (45%) 89 (55%) 0,180
CRM prévia 64 (8,2%) 34 (53,2%) 30 (46,8%) 0,703

Os stents INSPIRON® foram mais implantados nas artérias circunflexa, coronária direita e artéria descendente posterior em relação ao grupo “Outros SF’s”. Não houve diferença estatística entre os grupos em relação ao comprimento dos stents utilizados, nas vias de acessos arteriais e na porcentagem de stents submetidos a pré-dilatação. As ICP’s com stents INSPIRON® tiveram taxas estatisticamente significativas menores no uso de aterectomia rotacional e ultrassonografia intravascular (intravascular ultrasound – IVUS), no entanto, a taxa de utilização desses dispositivos foi muito baixa, não permitindo fazer correlações com eventos. Demais características angiográficas e do procedimento são apresentadas na Tabela 3.

– Características angiográficas e do procedimento
Variável Total n (%) INSPIRON® n (%*) Outros SF n (%*) p
Vaso Coronário Tratado (n = 783) (n = 392; 50%*) (n = 391; 50%*)
Descendente Anterior 293 (36%) 157 (53,5%) 136 (46,4%) 0,127
Circunflexa 139 (18%) 87 (62,5%) 52 (37,4%) 0,001
Coronária Direita 171 (22%) 102 (59,6%) 69 (40,3%) 0,004
Ramo Diagonal 68 (8,6%) 27 (39,7%) 33 (60,2%) 0,420
Obtuso Marginal 70 (8,9 %) 41 (58,5%) 29 (41,4%) 0,132
Descendente Posterior 31 (3,9%) 22 (70,9%) 8 (29%) 0,009
Póstero-lateral 14 (1,7%) 8 (57,1%) 6 (42,8%) 0,546
Enxerto Venoso 7 (0,89%) 1 (14,3%) 6 (85,7%) 0,057
Apresentação Clínica
Infarto com supra ST 145(18,5%) 81 (55,8%) 64 (44,1%) 0,117
Infarto sem supra ST 124(15,8%) 74 (59,6%) 50 (40,3%) 0,180
Angina Instável 316(40,4%) 127 (40,1%) 189 (59,8%) 0,001
Angina Estável 198(25,3%) 110 (55,5%) 88 (44,4%) 0,070
Avaliação Fisiológica
Fisiologia Invasiva 7 (0,89%) 1 (14,2%) 6 (85,7%) 0,057
Cintilografia Miocárdica 18 (2,3%) 6 (33,3%) 12 (66,6%) 0,152
Ecografia com Stress 1 (0,1%) 1 (100%) 0 (0%) 0,320
Teste Ergométrico 11 (1,4%) 5 (45,4%) 6 (54,5%) 0,860
Aspectos do Procedimento
Pré-dilatação 710(90%) 355 (50%) 355 (50%) 0,981
Aspiração de trombos 6 (0,8%) 4 (66,6%) 2 (33,3%) 0,412
Aterectomia Rotacional 9 (1,1%) 0 (0,0%) 9 (100%) 0,002
IVUS 8 (1,0%) 0 (0,0%) 8 (100%) 0,004
Pós-dilatação 369(47,1%) 171 (46,3%) 198 (53,6%) 0,049
Acesso arterial radial 588(75,1%) 285 (48,4%) 303 (51,5%) 0,121
Acesso arterial femoral 195(24,9%) 98 (50,2%) 97 (49,7%) 0,950
Comprimento de stent 21,46 22,05±6,0mm 21,45±7,2mm 0,717
Diâmetro de stent
- 2.0mm 16 (2,0%) 4 (25%) 12 (75%) 0,068
- 2.25mm 767 (97,9%) 386 (50,3%) 381 (49,6%) 0,862

* Proporções referentes às variáveis analisadas separadamente e não ao total da amostra. SF: stent farmacológico; IVUS: intravascular ultrasound – ultrassonografia intravascular.

O desfecho MACE geral foi 4,54% (36/793) e foi equivalente estatisticamente entre os grupos comparados (Tabela 4): 18 eventos no grupo “INSPIRON®” e 18 eventos no grupo “Outros SF’s” (Figura 2), assim como cada componente individual do desfecho composto. A taxa de trombose de stent foi similar entre os grupos de stents durante todos os períodos avaliados (Figura 3).

– Desfechos clínicos no acompanhamento de 12 meses
Período Grupo Stent Número de stents Intra-hospitalar 30 dias 6 meses 1 ano
Inspiron® 392 Outros 391 Inspiron® 392 Outros 391 Inspiron® 392 Outros 391 Inspiron® 392 Outros 391
MACE 0 (0%) 1(0,3%) 6(1,5%) 3 (0,8%) 10 (2,5%) 7(1,8%) 18(4,6%) 18(4,6%)
“p” p 0,499 p 0,505 p 0,625 p 1,000
RLA 0 (0%) 0 (0%) 1 (0,2%) 0 (0%) 2 (0,5%) 0 (0%) 4 (1,0%) 7 (1,8%)
“p” p 1,000 p 0,999 p 0,499 p 0,384
Infarto de lesão alvo 0 (0%) 1 (0,3%) 2(0,5%) 2(0,5%) 2(0,5%) 2(0,5%) 5(1,3%) 3(0,8%)
“p” p 0,499 p 1,000 p 1,000 p 0,725
Mortalidade cardíaca* 0 (0%) 0(0%) 3 (0,8%) 1 (0,3%) 6 (1,5%) 5(1,3%) 9(2,3%) 8(2,1%)
“p” p 1,000 p 0,624 p 0,999 p 0,999

MACE: Major Adverse Cardiovascular Events (mortalidade cardíaca, infarto da lesão alvo e revascularização de lesão alvo clinicamente dirigida; RLA: revascularização de lesão alvo clinicamente dirigida; Mortalidade cardíaca*: mortalidade cardíaca confirmada e provável.

– Eventos de MACE acumulados por períodos avaliados. Número acumulado de eventos de MACE (mortalidade cardíaca, infarto da lesão alvo e revascularização de lesão alvo clinicamente dirigida) durante os períodos de avaliação em cada grupo de stent.

– Trombose de stent durante períodos avaliado. Número acumulado de eventos de trombose de stent durante os períodos de avaliação em cada grupo de stent.

A taxa de mortalidade cardíaca confirmada e provável total na amostra foi de 2,14% (17/793) similar entre os grupos estudados. O seguimento clínico foi similar entre os grupos, sendo que houve perda de seguimento de 42 pacientes (5,5%) durante o período de um ano.

Durante o seguimento de um ano, não houve diferença na taxa de stents livres de desfechos (Figura 4). Durante os seguimentos de seis meses e um ano, os grupos mantiveram uso de terapias antiagregantes de forma semelhantes.

– Curva de Kaplan-Meier. Curva de sobrevida acumulada livre de MACE (mortalidade cardíaca, infarto da lesão alvo e revascularização de lesão alvo clinicamente dirigida) durante o período de 365 dias de seguimento.

Discussão

Esse registro contemporâneo de mundo real, o qual avaliou os dados clínicos brasileiros em pacientes submetidos a ICP com stent em vasos de muito pequeno calibre, demonstrou baixas taxas de MACE, resultados similares entre os diferentes tipos de dispositivos disponíveis comparados (Figura Central) e dados da literatura.23,24

A presença de diabetes mellitus está frequentemente associada a doença aterosclerótica coronariana difusa em pequenos vasos, além de ser considerada preditor de reestenose e trombose de stent após ICP com SFs.25-35 Em nossa amostra, dos stents que apresentaram MACE, 42% (15/36) foram implantados em pacientes com diagnóstico prévio de diabetes mellitus, tendo a mesma frequência na amostra geral. A maioria dos pacientes submetidos a ICP necessitaram comprimentos de malha de stents (>20mm), embora os stents com MACE não tiveram comprimento médio maior que os stents livres de eventos (21,98mm vs. 21,43mm, p,0820). Ademais, embora algumas diferentes taxas entre os grupos de stents implantados nos aspectos clínicos, a análise de MACE dos stents “INSPIRON®” e “Outros SF’s” não demonstrou diferença significativa em pacientes com insuficiência cardíaca com fração de ejeção <50% (4/18 stents [22%] vs. 3 stents [17%], p 0,67), apresentação clínica da intervenção índice como síndrome coronariana aguda (8/18 stents [44,4%] vs. 9/18 stents [50%], p 0,74). O pequeno número de desfechos durante o seguimento, impossibilitou uma análise multivariada de outras características clínicas e do procedimento.

O potencial efeito de menor lesão endotelial pelas plataformas com hastes mais finas, foi testado em nossa amostra quando comparamos stents com hastes <80 µm (447 stents – 57%) e os demais, embora não apresentem significância estatística entre o Inspiron® e Outros SFs (48% vs. 52%, p=1,010, respectivamente); É possível que em uma amostra maior de pacientes ou em estudos com acompanhamento angiográfico de rotina seja possível identificar esta diferença uma vez que o desenvolvimento de sintomas agudos ou crônicos, principais motivos para uma nova estratificação invasiva em nossa amostra, pode ser subestimada devido a menor área isquêmica em risco e, consequentemente, menor possibilidade de sintomas.

Ao analisar resultados conforme o tipo de droga eluida nos dispositivos, os dados desta amostra demonstram uma equivalência estatística de MACE entre o stent eluidor de Sirolimus (Inspiron®) e dispositivos com outros fármacos, sugerindo haver um efeito de classe dos SF’s disponíveis e corroborando os dados científicos atuais.36-39 Estes achados, sugerem também que diversas outras características de engenharia e bioquímicas dos SF’s contemporâneos podem minimizar a importância do tipo de droga presente na plataforma.

O uso de imagem intravascular, representado pelo IVUS, impacta em resultados angiográficos e clínicos agudos e a longo prazo.40-43 A taxa de uso destas ferramentas foi baixa em nossa amostra, apenas 1% (8/783) dos casos, visto que os procedimentos foram realizados, em sua grande maioria, em pacientes da rede pública de saúde, a qual não financiava a tecnologia. Ademais, o uso de imagem intravascular em vasos <2,25 mm pode ser desafiador, aumentando o risco de lesão iatrogênica da placa,41 o que pode ter influenciado na escolha do operador.

O padrão de dispersão difusa dos eventos de trombose de stent em nossa amostra sugere que fatores técnicos agudos relacionados ao procedimento, como má expansão e dissecções coronárias significativas, não foram fatores que tiveram alta influência nas taxas de desfechos (Tabela 5).

– Trombose de stent
Período Tipo de Stent N, (%) Intra-hospitalar 30 dias 6 meses 1 ano
Inspiron® Outros Inspiron® Outros Inspiron® Outros Inspiron® Outros
Trombose de stent* 0 (0%) 1 (0,3%) 2 (0,5%) 2(0,5%) 2(0,5%) 2 (0,5%) 4(1,0%) 2(0,5%)
“p” p 0,499 p 1,000 p 1,000 p 0,868

Taxa cumulativa de trombose de stent durante períodos. Trombose de stent*: Trombose de stent confirmada.

O uso e duração da terapia antiplaquetária após ICP foram similares durante o seguimento dos pacientes, com alta taxa manutenção de dupla antiagregação aos 12 meses, o que pode ter influenciado na frequência de desfechos (Tabela 6).

– Terapia médica antiplaquetária
Terapia Médica aos 6 meses, n* (%) INSPIRON® (382/ 392) Outros SF (383/ 391) “p”
AAS 364 (95,2%) 369 (96,3%) 0,242
Inibidores da ADP
Clopidogrel 356 (93,1%) 362 (94,5%) 0,323
Prasugrel 7 (1,8%) 3 (0,7%) 0,201
Ticagrelor 1 (0,2%) 0 (0%) 0,317
Nenhum 7 (1,8%) 8 (2,0%) 0,798
Qualquer ADP† 371 (97,1%) 373 (97,3%) 0,820
Terapia Médica a 1 ano, n* (%) INSPIRON® (374/ 392) Outros SF (375/ 391) “p”
AAS 357 (95,4%) 355 (94,6%) 0,561
Qualquer inibidor da ADP† 337 (90,1%) 332 (88,5%) 0,469

*: Número de stents nos grupos, excluídos óbitos, durante o período mencionado. Qualquer ADP†: número de pacientes em uso de qualquer tipo de inibidores de ADP. SF: stent farmacológico; ADP: adenosina difosfato.

O presente estudo tem limitações relacionadas aos estudos não randomizados e à disponibilidade momentânea dos dispositivos. A reestenose pode ter sido subdiagnosticada devido a não realização de cateterismo de rotina, embora a reestenose mais tardia (>12 meses), tende a ser mais relacionada à progressão da doença aterosclerótica à ICP prévia. Ademais, agrupar diferentes DES apenas com base na espessura da haste ou medicamento eluido pode não ser apropriado, uma vez que os outros componentes como o desenho do stent, morfologia das hastes e conexões, presença e tipo do metabolismo de polímeros utilizados, também podem influenciar o desempenho. No entanto, este estudo representa uma significativa amostra de mundo real em centro de alto volume, com critérios de inclusão amplos e dados clínicos altamente aplicáveis.

O desenvolvimento da terapia com balões eluidos de fármacos (Drug eluted balloons – DEB) vem sendo testada, com uma proposta racional de evitar o implante de malhas metálicas.23,24,44,45 Estudos comparativos sobre implante de stents de última geração vs. DEB’s, em lesões “de novo” em pacientes com vasos de muito fino calibre (<2,5mm), como no nosso estudo, são fundamentais para guiar a melhor alternativa terapêutica para estes indivíduos.

 Conclusão

A intervenção coronária percutânea em vasos de muito pequeno calibre com stents farmacológicos contemporâneos demonstram satisfatórios resultados clínicos em 12 meses de seguimento, favoráveis à manutenção dessa terapia e utilização dos stents avaliados.

 Referências 1. Cortese B, Di Palma G, Guimaraes MG, Piraino D, Orrego PS, Buccheri D, et al. Drug-Coated Balloon Versus Drug-Eluting Stent for Small Coronary Vessel Disease: PICCOLETO II Randomized Clinical Trial. JACC Cardiovasc Interv. 2020;13(24):2840-9. doi: 10.1016/j.jcin.2020.08.035. Cortese B Di Palma G Guimaraes MG Piraino D Orrego PS Buccheri D et al Drug-Coated Balloon Versus Drug-Eluting Stent for Small Coronary Vessel Disease: PICCOLETO II Randomized Clinical Trial JACC Cardiovasc Interv 2020 13 24 2840 2849 10.1016/j.jcin.2020.08.035 2. Landes U, Bental T, Levi A, Assali A, Vaknin-Assa H, Lev EI, et al. Temporal Trends in Percutaneous Coronary Interventions thru the Drug Eluting Stent Era: Insights from 18,641 Procedures Performed Over 12-Year Period. Catheter Cardiovasc Interv. 2018;92(4):E262-E270. doi: 10.1002/ccd.27375. Landes U Bental T Levi A Assali A Vaknin-Assa H Lev EI et al Temporal Trends in Percutaneous Coronary Interventions thru the Drug Eluting Stent Era: Insights from 18,641 Procedures Performed Over 12-Year Period Catheter Cardiovasc Interv 2018 92 4 E262 E270 10.1002/ccd.27375 3. Wöhrle J, Markovic S, Rottbauer W, Muramatsu T, Kadota K, Vázquez-González N, et al. Bioresorbable Polymer Sirolimus-Eluting Coronary Stent Compared with Permanent Polymer Everolimus-Eluting Coronary Stent Implantation for Treatment of Small Vessel Coronary Artery Disease: CENTURY II Trial. EuroIntervention. 2016;12(2):e167-74. doi: 10.4244/EIJV12I2A30. Wöhrle J Markovic S Rottbauer W Muramatsu T Kadota K Vázquez-González N et al Bioresorbable Polymer Sirolimus-Eluting Coronary Stent Compared with Permanent Polymer Everolimus-Eluting Coronary Stent Implantation for Treatment of Small Vessel Coronary Artery Disease: CENTURY II Trial EuroIntervention 2016 12 2 e167 e174 10.4244/EIJV12I2A30 4. Schunkert H, Harrell L, Palacios IF. Implications of Small Reference Vessel Diameter in Patients Undergoing Percutaneous Coronary Revascularization. J Am Coll Cardiol. 1999;34(1):40-8. doi: 10.1016/s0735-1097(99)00181-3. Schunkert H Harrell L Palacios IF Implications of Small Reference Vessel Diameter in Patients Undergoing Percutaneous Coronary Revascularization J Am Coll Cardiol 1999 34 1 40 48 10.1016/s0735-1097(99)00181-3 5. Mosseri M, Yarom R, Gotsman MS, Hasin Y. Histologic Evidence for Small-Vessel Coronary Artery Disease in Patients with Angina Pectoris and Patent Large Coronary Arteries. Circulation. 1986;74(5):964-72. doi: 10.1161/01.cir.74.5.964. Mosseri M Yarom R Gotsman MS Hasin Y Histologic Evidence for Small-Vessel Coronary Artery Disease in Patients with Angina Pectoris and Patent Large Coronary Arteries Circulation 1986 74 5 964 972 10.1161/01.cir.74.5.964 6. Ellis SG, Popma JJ, Lasala JM, Koglin JJ, Cox DA, Hermiller J, et al. Relationship between Angiographic Late Loss and Target Lesion Revascularization after Coronary Stent Implantation: Analysis from the TAXUS-IV Trial. J Am Coll Cardiol. 2005;45(8):1193-200. doi: 10.1016/j.jacc.2004.11.063. Ellis SG Popma JJ Lasala JM Koglin JJ Cox DA Hermiller J et al Relationship between Angiographic Late Loss and Target Lesion Revascularization after Coronary Stent Implantation: Analysis from the TAXUS-IV Trial J Am Coll Cardiol 2005 45 8 1193 1200 10.1016/j.jacc.2004.11.063 7. Ertan C, Ozeke O, Gul M, Aras D, Topaloglu S, Kisacik HL, et al. Association of Prediabetes with Diffuse Coronary Narrowing and Small-Vessel Disease. J Cardiol. 2014;63(1):29-34. doi: 10.1016/j.jjcc.2013.06.015. Ertan C Ozeke O Gul M Aras D Topaloglu S Kisacik HL et al Association of Prediabetes with Diffuse Coronary Narrowing and Small-Vessel Disease J Cardiol 2014 63 1 29 34 10.1016/j.jjcc.2013.06.015 8. Lee JZ, Singh N, Ortega G, Low SW, Kanakadandi U, Fortuin FD, et al. Composite Outcomes in 2.25-mm Drug Eluting Stents: A Systematic Review. Cardiovasc Revasc Med. 2015;16(4):237-42. doi: 10.1016/j.carrev.2015.03.008. Lee JZ Singh N Ortega G Low SW Kanakadandi U Fortuin FD et al Composite Outcomes in 2.25-mm Drug Eluting Stents: A Systematic Review Cardiovasc Revasc Med 2015 16 4 237 242 10.1016/j.carrev.2015.03.008 9. Tam CC, Chan K, Lam S, Yung A, Lam YM, Chan C, et al. One-Year Clinical Outcomes of Patients Implanted with a Resolute Onyx™ Zotarolimus-Eluting Stent. J Int Med Res. 2018;46(1):457-463. doi: 10.1177/0300060517717826. Tam CC Chan K Lam S Yung A Lam YM Chan C et al One-Year Clinical Outcomes of Patients Implanted with a Resolute Onyx™ Zotarolimus-Eluting Stent J Int Med Res 2018 46 1 457 463 10.1177/0300060517717826 10. Wybraniec MT, Banka P, Bochenek T, Roleder T, Mizia-Stec K. Small Vessel Coronary Artery Disease: How Small can we go with Myocardial Revascularization? Cardiol J. 2021;28(5):767-78. doi: 10.5603/CJ.a2020.0127. Wybraniec MT Banka P Bochenek T Roleder T Mizia-Stec K Small Vessel Coronary Artery Disease: How Small can we go with Myocardial Revascularization? Cardiol J 2021 28 5 767 778 10.5603/CJ.a2020.0127 11. van der Heijden LC, Kok MM, Danse PW, Schramm AR, Hartmann M, Löwik MM, et al. Small-Vessel Treatment with Contemporary Newer-Generation Drug-Eluting Coronary Stents in All-Comers: Insights from 2-year DUTCH PEERS (TWENTE II) Randomized Trial. Am Heart J. 2016;176:28-35. doi: 10.1016/j.ahj.2016.02.020. van der Heijden LC Kok MM Danse PW Schramm AR Hartmann M Löwik MM et al Small-Vessel Treatment with Contemporary Newer-Generation Drug-Eluting Coronary Stents in All-Comers: Insights from 2-year DUTCH PEERS (TWENTE II) Randomized Trial Am Heart J 2016 176 28 35 10.1016/j.ahj.2016.02.020 12. Cassese S, Byrne RA, Tada T, Pinieck S, Joner M, Ibrahim T, et al. Incidence and Predictors of Restenosis after Coronary Stenting in 10 004 Patients with Surveillance Angiography. Heart. 2014;100(2):153-9. doi: 10.1136/heartjnl-2013-304933. Cassese S Byrne RA Tada T Pinieck S Joner M Ibrahim T et al Incidence and Predictors of Restenosis after Coronary Stenting in 10 004 Patients with Surveillance Angiography Heart 2014 100 2 153 159 10.1136/heartjnl-2013-304933 13. Claessen BE, Smits PC, Kereiakes DJ, Parise H, Fahy M, Kedhi E, et al. Impact of Lesion Length and Vessel Size on Clinical Outcomes after Percutaneous Coronary Intervention with Everolimus- versus Paclitaxel-Eluting Stents Pooled Analysis from the SPIRIT (Clinical Evaluation of the XIENCE V Everolimus Eluting Coronary Stent System) and COMPARE (Second-Generation Everolimus-Eluting and Paclitaxel-Eluting Stents in Real-Life Practice) Randomized Trials. JACC Cardiovasc Interv. 2011;4(11):1209-15. doi: 10.1016/j.jcin.2011.07.016. Claessen BE Smits PC Kereiakes DJ Parise H Fahy M Kedhi E et al Impact of Lesion Length and Vessel Size on Clinical Outcomes after Percutaneous Coronary Intervention with Everolimus- versus Paclitaxel-Eluting Stents Pooled Analysis from the SPIRIT (Clinical Evaluation of the XIENCE V Everolimus Eluting Coronary Stent System) and COMPARE (Second-Generation Everolimus-Eluting and Paclitaxel-Eluting Stents in Real-Life Practice) Randomized Trials JACC Cardiovasc Interv 2011 4 11 1209 1215 10.1016/j.jcin.2011.07.016 14. O'Connor NJ, Morton JR, Birkmeyer JD, Olmstead EM, O'Connor GT. Effect of Coronary Artery Diameter in Patients Undergoing Coronary Bypass Surgery. Northern New England Cardiovascular Disease Study Group. Circulation. 1996;93(4):652-5. doi: 10.1161/01.cir.93.4.652. O'Connor NJ Morton JR Birkmeyer JD Olmstead EM O'Connor GT Effect of Coronary Artery Diameter in Patients Undergoing Coronary Bypass Surgery. Northern New England Cardiovascular Disease Study Group Circulation 1996 93 4 652 655 10.1161/01.cir.93.4.652 15. Limanto DH, Chang HW, Kim DJ, Kim JS, Park KH, Lim C. Coronary Artery Size as a Predictor of Y-Graft Patency Following Coronary Artery Bypass Surgery. Medicine. 2021;100(2):e24063. doi: 10.1097/MD.0000000000024063. Limanto DH Chang HW Kim DJ Kim JS Park KH Lim C Coronary Artery Size as a Predictor of Y-Graft Patency Following Coronary Artery Bypass Surgery Medicine 2021 100 2 e24063 10.1097/MD.0000000000024063 16. Shah PJ, Gordon I, Fuller J, Seevanayagam S, Rosalion A, Tatoulis J, et al. Factors affecting Saphenous Vein Graft Patency: Clinical and Angiographic Study in 1402 Symptomatic Patients Operated on Between 1977 and 1999. J Thorac Cardiovasc Surg. 2003;126(6):1972-7. doi: 10.1016/s0022-5223(03)01276-5. Shah PJ Gordon I Fuller J Seevanayagam S Rosalion A Tatoulis J et al Factors affecting Saphenous Vein Graft Patency: Clinical and Angiographic Study in 1402 Symptomatic Patients Operated on Between 1977 and 1999 J Thorac Cardiovasc Surg 2003 126 6 1972 1977 10.1016/s0022-5223(03)01276-5 17. Foin N, Lee RD, Torii R, Guitierrez-Chico JL, Mattesini A, Nijjer S, et al. Impact of Stent Strut Design in Metallic Stents and Biodegradable Scaffolds. Int J Cardiol. 2014;177(3):800-8. doi: 10.1016/j.ijcard.2014.09.143. Foin N Lee RD Torii R Guitierrez-Chico JL Mattesini A Nijjer S et al Impact of Stent Strut Design in Metallic Stents and Biodegradable Scaffolds Int J Cardiol 2014 177 3 800 808 10.1016/j.ijcard.2014.09.143 18. Briguori C, Sarais C, Pagnotta P, Liistro F, Montorfano M, Chieffo A, et al. In-Stent Restenosis in Small Coronary Arteries: Impact of Strut Thickness. J Am Coll Cardiol. 2002;40(3):403-9. doi: 10.1016/s0735-1097(02)01989-7. Briguori C Sarais C Pagnotta P Liistro F Montorfano M Chieffo A et al In-Stent Restenosis in Small Coronary Arteries: Impact of Strut Thickness J Am Coll Cardiol 2002 40 3 403 409 10.1016/s0735-1097(02)01989-7 19. Kolandaivelu K, Swaminathan R, Gibson WJ, Kolachalama VB, Nguyen-Ehrenreich KL, Giddings VL, et al. Stent Thrombogenicity Early in High-Risk Interventional Settings is Driven by Stent Design and Deployment and Protected by Polymer-Drug Coatings. Circulation. 2011;123(13):1400-9. doi: 10.1161/CIRCULATIONAHA.110.003210. Kolandaivelu K Swaminathan R Gibson WJ Kolachalama VB Nguyen-Ehrenreich KL Giddings VL et al Stent Thrombogenicity Early in High-Risk Interventional Settings is Driven by Stent Design and Deployment and Protected by Polymer-Drug Coatings Circulation 2011 123 13 1400 1409 10.1161/CIRCULATIONAHA.110.003210 20. Buiten RA, Ploumen EH, Zocca P, Doggen CJM, Jessurun GAJ, Schotborgh CE, et al. Thin Composite-Wire-Strut Zotarolimus-Eluting Stents versus Ultrathin-Strut Sirolimus-Eluting Stents in BIONYX at 2 Years. JACC Cardiovasc Interv. 2020;13(9):1100-1109. doi: 10.1016/j.jcin.2020.01.230. Buiten RA Ploumen EH Zocca P Doggen CJM Jessurun GAJ Schotborgh CE et al Thin Composite-Wire-Strut Zotarolimus-Eluting Stents versus Ultrathin-Strut Sirolimus-Eluting Stents in BIONYX at 2 Years JACC Cardiovasc Interv 2020 13 9 1100 1109 10.1016/j.jcin.2020.01.230 21. Kang DY, Jang JS, Chang M, Lee CH, Lee PH, Ahn JM, et al. Comparison of Different Types of Drug-Eluting Stents for De Novo Long Coronary Artery Lesions. JACC Asia. 2022;2(4):446-456. doi: 10.1016/j.jacasi.2022.02.009. Kang DY Jang JS Chang M Lee CH Lee PH Ahn JM et al Comparison of Different Types of Drug-Eluting Stents for De Novo Long Coronary Artery Lesions JACC Asia 2022 2 4 446 456 10.1016/j.jacasi.2022.02.009 22. Winter RJ, Zaman A, Hara H, Gao C, Ono M, Garg S, et al. Sirolimus-Eluting Stents with Ultrathin Struts Versus Everolimus-Eluting Stents for Patients Undergoing Percutaneous Coronary Intervention: Final Three-Year Results of the TALENT Trial. EuroIntervention. 2022;18(6):492-502. doi: 10.4244/EIJ-D-21-00766. Winter RJ Zaman A Hara H Gao C Ono M Garg S et al Sirolimus-Eluting Stents with Ultrathin Struts Versus Everolimus-Eluting Stents for Patients Undergoing Percutaneous Coronary Intervention: Final Three-Year Results of the TALENT Trial EuroIntervention 2022 18 6 492 502 10.4244/EIJ-D-21-00766 23. Saito S, Ando K, Ito Y, Tobaru T, Yajima J, Kimura T, et al. Two-Year Results after Coronary Stenting of Small Vessels in Japanese Population Using 2.25-mm Diameter Sirolimus-Eluting Stent with Bioresorbable Polymer: Primary and Long-Term Outcomes of CENTURY JSV Study. Cardiovasc Interv Ther. 2019;34(1):25-33. doi: 10.1007/s12928-018-0511-3. Saito S Ando K Ito Y Tobaru T Yajima J Kimura T et al Two-Year Results after Coronary Stenting of Small Vessels in Japanese Population Using 2.25-mm Diameter Sirolimus-Eluting Stent with Bioresorbable Polymer: Primary and Long-Term Outcomes of CENTURY JSV Study Cardiovasc Interv Ther 2019 34 1 25 33 10.1007/s12928-018-0511-3 24. Parikh MA, Soverow J, Leon MB, Serruys P, Xu B, Yuan Z, et al. Outcomes of Stenting Extra-Small (=2.25 mm) Vessels Using the Resolute Zotarolimus-Eluting Stent (R-ZES). EuroIntervention. 2016;12(10):1215-1221. doi: 10.4244/EIJV12I10A200. Parikh MA Soverow J Leon MB Serruys P Xu B Yuan Z et al Outcomes of Stenting Extra-Small (=2.25 mm) Vessels Using the Resolute Zotarolimus-Eluting Stent (R-ZES) EuroIntervention 2016 12 10 1215 1221 10.4244/EIJV12I10A200 25. Cassese S, Byrne RA, Tada T, Pinieck S, Joner M, Ibrahim T, et al. Incidence and Predictors of Restenosis after Coronary Stenting in 10 004 Patients with Surveillance Angiography. Heart. 2014;100(2):153-9. doi: 10.1136/heartjnl-2013-304933. Cassese S Byrne RA Tada T Pinieck S Joner M Ibrahim T et al Incidence and Predictors of Restenosis after Coronary Stenting in 10 004 Patients with Surveillance Angiography Heart 2014 100 2 153 159 10.1136/heartjnl-2013-304933 26. Rathore S. Small Coronary Vessel Angioplasty: Outcomes and Technical Considerations. Vasc Health Risk Manag. 2010;6:915-22. doi: 10.2147/VHRM.S8161. Rathore S Small Coronary Vessel Angioplasty: Outcomes and Technical Considerations Vasc Health Risk Manag 2010 6 915 922 10.2147/VHRM.S8161 27. Kastrati A, Dirschinger J, Boekstegers P, Elezi S, Schühlen H, Pache J, et al. Influence of Stent Design on 1-Year Outcome after Coronary Stent Placement: A Randomized Comparison of Five Stent Types in 1,147 Unselected Patients. Catheter Cardiovasc Interv. 2000;50(3):290-7. doi: 10.1002/1522-726x(200007)50:3<290::aid-ccd5>3.0.co;2-w. Kastrati A Dirschinger J Boekstegers P Elezi S Schühlen H Pache J et al Influence of Stent Design on 1-Year Outcome after Coronary Stent Placement: A Randomized Comparison of Five Stent Types in 1,147 Unselected Patients Catheter Cardiovasc Interv 2000 50 3 290 297 10.1002/1522-726x(200007)50:3<290::aid-ccd5>3.0.co;2-w 28. Oliveira MD, Ribeiro EE, Campos CM, Ribeiro HB, Faillace BL, Lopes AC, et al. Four-Year Clinical Follow-Up of the First-In-Man Randomized Comparison of a Novel Sirolimus Eluting Stent with Abluminal Biodegradable Polymer and Ultra-Thin Strut Cobalt-Chromium Alloy: The INSPIRON-I Trial. Cardiovasc Diagn Ther. 2015;5(4):264-70. doi: 10.3978/j.issn.2223-3652.2015.07.05. Oliveira MD Ribeiro EE Campos CM Ribeiro HB Faillace BL Lopes AC et al Four-Year Clinical Follow-Up of the First-In-Man Randomized Comparison of a Novel Sirolimus Eluting Stent with Abluminal Biodegradable Polymer and Ultra-Thin Strut Cobalt-Chromium Alloy: The INSPIRON-I Trial Cardiovasc Diagn Ther 2015 5 4 264 270 10.3978/j.issn.2223-3652.2015.07.05 29. Falcão F, Cantarelli F, Cantarelli R, Mota F, Navarro M, Mota H, et al. One-Year Clinical Outcome of Inspiron Stent in All-Comers Population (Analysis from 790 Consecutive Patients). J Interv Cardiol. 2020;2020:6340716. doi: 10.1155/2020/6340716. Falcão F Cantarelli F Cantarelli R Mota F Navarro M Mota H et al One-Year Clinical Outcome of Inspiron Stent in All-Comers Population (Analysis from 790 Consecutive Patients) J Interv Cardiol 2020 2020 6340716 10.1155/2020/6340716 30. Araujo GN, Machado GP, Moura M, Silveira AD, Bergoli LC, Fuchs FC, et al. Real-World Assessment of an Ultrathin Strut, Sirolimus-Eluting Stent in Patients with ST-Elevation Myocardial Infarction Submitted to Primary Percutaneous Coronary Intervention (INSTEMI Registry). Arq Bras Cardiol. 2023;120(6):e20220594. doi: 10.36660/abc.20220594. Araujo GN Machado GP Moura M Silveira AD Bergoli LC Fuchs FC et al Real-World Assessment of an Ultrathin Strut, Sirolimus-Eluting Stent in Patients with ST-Elevation Myocardial Infarction Submitted to Primary Percutaneous Coronary Intervention (INSTEMI Registry) Arq Bras Cardiol 2023 120 6 e20220594 10.36660/abc.20220594 31. Thygesen K, Alpert JS, Jaffe AS, Chaitman BR, Bax JJ, Morrow DA, et al. Fourth Universal Definition of Myocardial Infarction (2018). J Am Coll Cardiol. 2018;72(18):2231-64. doi: 10.1016/j.jacc.2018.08.1038. Thygesen K Alpert JS Jaffe AS Chaitman BR Bax JJ Morrow DA et al Fourth Universal Definition of Myocardial Infarction (2018) J Am Coll Cardiol 2018 72 18 2231 2264 10.1016/j.jacc.2018.08.1038 32. Feres F, Costa RA, Siqueira D, Costa JR Jr, Chamié D, Staico R, et al. Diretriz da Sociedade Brasileira de Cardiologia e da Sociedade Brasileira de Hemodinâmica e Cardiologia Intervencionista sobre Intervenção Coronária Percutânea. Arq Bras Cardiol. 2017;109(1 Suppl 1):1-81. doi: 10.5935/abc.20170111. Feres F Costa RA Siqueira D Costa JR Jr Chamié D Staico R et al Diretriz da Sociedade Brasileira de Cardiologia e da Sociedade Brasileira de Hemodinâmica e Cardiologia Intervencionista sobre Intervenção Coronária Percutânea Arq Bras Cardiol 2017 109 1 Suppl 1 1 81 10.5935/abc.20170111 33. Iakovou I, Schmidt T, Bonizzoni E, Ge L, Sangiorgi GM, Stankovic G, et al. Incidence, Predictors, and Outcome of Thrombosis after Successful Implantation of Drug-Eluting Stents. JAMA. 2005;293(17):2126-30. doi: 10.1001/jama.293.17.2126. Iakovou I Schmidt T Bonizzoni E Ge L Sangiorgi GM Stankovic G et al Incidence, Predictors, and Outcome of Thrombosis after Successful Implantation of Drug-Eluting Stents JAMA 2005 293 17 2126 2130 10.1001/jama.293.17.2126 34. West NE, Ruygrok PN, Disco CM, Webster MW, Lindeboom WK, O'Neill WW, et al. Clinical and Angiographic Predictors of Restenosis after Stent Deployment in Diabetic Patients. Circulation. 2004;109(7):867-73. doi: 10.1161/01.CIR.0000116750.63158.94. West NE Ruygrok PN Disco CM Webster MW Lindeboom WK O'Neill WW et al Clinical and Angiographic Predictors of Restenosis after Stent Deployment in Diabetic Patients Circulation 2004 109 7 867 873 10.1161/01.CIR.0000116750.63158.94 35. Dortimer AC, Shenoy PN, Shiroff RA, Leaman DM, Babb JD, Liedtke AJ, et al. Diffuse Coronary Artery Disease in Diabetic Patients: Fact or Fiction? Circulation. 1978;57(1):133-6. doi: 10.1161/01.cir.57.1.133. Dortimer AC Shenoy PN Shiroff RA Leaman DM Babb JD Liedtke AJ et al Diffuse Coronary Artery Disease in Diabetic Patients: Fact or Fiction? Circulation 1978 57 1 133 136 10.1161/01.cir.57.1.133 36. Taglieri N, Bruno AG, Ghetti G, Marrozzini C, Saia F, Galié N, et al. Target Lesion Failure with Current Drug-Eluting Stents: Evidence from a Comprehensive Network Meta-Analysis. JACC Cardiovasc Interv. 2020;13(24):2868-78. doi: 10.1016/j.jcin.2020.09.014. Taglieri N Bruno AG Ghetti G Marrozzini C Saia F Galié N et al Target Lesion Failure with Current Drug-Eluting Stents: Evidence from a Comprehensive Network Meta-Analysis JACC Cardiovasc Interv 2020 13 24 2868 2878 10.1016/j.jcin.2020.09.014 37. Bangalore S, Toklu B, Patel N, Feit F, Stone GW. Newer-Generation Ultrathin Strut Drug-Eluting Stents versus Older Second-Generation Thicker Strut Drug-Eluting Stents for Coronary Artery Disease. Circulation. 2018;138(20):2216-26. doi: 10.1161/CIRCULATIONAHA.118.034456. Bangalore S Toklu B Patel N Feit F Stone GW Newer-Generation Ultrathin Strut Drug-Eluting Stents versus Older Second-Generation Thicker Strut Drug-Eluting Stents for Coronary Artery Disease Circulation 2018 138 20 2216 2226 10.1161/CIRCULATIONAHA.118.034456 38. Park KW, Kang SH, Velders MA, Shin DH, Hahn S, Lim WH, et al. Safety and Efficacy of Everolimus- versus Sirolimus-Eluting Stents: A Systematic Review and Meta-Analysis of 11 Randomized Trials. Am Heart J. 2013;165(2):241-50.e4. doi: 10.1016/j.ahj.2012.08.007. Park KW Kang SH Velders MA Shin DH Hahn S Lim WH et al Safety and Efficacy of Everolimus- versus Sirolimus-Eluting Stents: A Systematic Review and Meta-Analysis of 11 Randomized Trials Am Heart J 2013 165 2 241 50.e4 10.1016/j.ahj.2012.08.007 39. Waha A, Dibra A, Byrne RA, Ndrepepa G, Mehilli J, Fusaro M, et al. Everolimus-Eluting versus Sirolimus-Eluting Stents: A Meta-Analysis of Randomized Trials. Circ Cardiovasc Interv. 2011;4(4):371-7. doi: 10.1161/CIRCINTERVENTIONS.111.963256. Waha A Dibra A Byrne RA Ndrepepa G Mehilli J Fusaro M et al Everolimus-Eluting versus Sirolimus-Eluting Stents: A Meta-Analysis of Randomized Trials Circ Cardiovasc Interv 2011 4 4 371 377 10.1161/CIRCINTERVENTIONS.111.963256 40. Li L, Wang L, Zhai CJ, Mou YR, Wang JH, Cui LQ. Clinical Utility of Intravascular Ultrasonography-Guided Therapy in a Small-Vessel Coronary Lesion Associated with Type 2 Diabetes Mellitus. Anatol J Cardiol. 2019;22(2):68-76. doi: 10.14744/AnatolJCardiol.2019.77009. Li L Wang L Zhai CJ Mou YR Wang JH Cui LQ Clinical Utility of Intravascular Ultrasonography-Guided Therapy in a Small-Vessel Coronary Lesion Associated with Type 2 Diabetes Mellitus Anatol J Cardiol 2019 22 2 68 76 10.14744/AnatolJCardiol.2019.77009 41. Matsuo Y, Kubo T, Aoki H, Satogami K, Ino Y, Kitabata H, et al. Optimal Threshold of Postintervention Minimum Stent Area to Predict In-Stent Restenosis in Small Coronary Arteries: An Optical Coherence Tomography Analysis. Catheter Cardiovasc Interv. 2016;87(1):E9-E14. doi: 10.1002/ccd.26143. Matsuo Y Kubo T Aoki H Satogami K Ino Y Kitabata H et al Optimal Threshold of Postintervention Minimum Stent Area to Predict In-Stent Restenosis in Small Coronary Arteries: An Optical Coherence Tomography Analysis Catheter Cardiovasc Interv 2016 87 1 E9 E14 10.1002/ccd.26143 42. Elgendy IY, Mahmoud AN, Elgendy AY, Bavry AA. Outcomes with Intravascular Ultrasound-Guided Stent Implantation: A Meta-Analysis of Randomized Trials in the Era of Drug-Eluting Stents. Circ Cardiovasc Interv. 2016;9(4):e003700. doi: 10.1161/CIRCINTERVENTIONS.116.003700. Elgendy IY Mahmoud AN Elgendy AY Bavry AA Outcomes with Intravascular Ultrasound-Guided Stent Implantation: A Meta-Analysis of Randomized Trials in the Era of Drug-Eluting Stents Circ Cardiovasc Interv 2016 9 4 e003700 10.1161/CIRCINTERVENTIONS.116.003700 43. Kordish I, Philipp S, Boese D, Sack S, Erbel R. Dissection of the Right Coronary Artery as a Complication after the IVUS Procedure. Herz. 2007;32(7):573-7. doi: 10.1007/s00059-007-2900-8. Kordish I Philipp S Boese D Sack S Erbel R Dissection of the Right Coronary Artery as a Complication after the IVUS Procedure Herz 2007 32 7 573 577 10.1007/s00059-007-2900-8 44. Jeger RV, Farah A, Ohlow MA, Mangner N, Möbius-Winkler S, Leibundgut G, et al. Drug-Coated Balloons for Small Coronary Artery Disease (BASKET-SMALL 2): An Open-Label Randomised Non-Inferiority Trial. Lancet. 2018;392(10150):849-56. doi: 10.1016/S0140-6736(18)31719-7. Jeger RV Farah A Ohlow MA Mangner N Möbius-Winkler S Leibundgut G et al Drug-Coated Balloons for Small Coronary Artery Disease (BASKET-SMALL 2): An Open-Label Randomised Non-Inferiority Trial Lancet 2018 392 10150 849 856 10.1016/S0140-6736(18)31719-7 45. Richelsen RK, Overvad TF, Jensen SE. Drug-Eluting Balloons in the Treatment of Coronary De Novo Lesions: A Comprehensive Review. Cardiol Ther. 2016;5(2):133-160. doi: 10.1007/s40119-016-0064-4. Richelsen RK Overvad TF Jensen SE Drug-Eluting Balloons in the Treatment of Coronary De Novo Lesions: A Comprehensive Review Cardiol Ther 2016 5 2 133 160 10.1007/s40119-016-0064-4

Este artigo é parte de dissertação de mestrado de João Vitor Slaviero pelo Instituto de Cardiologia de Porto Alegre.

Este estudo foi aprovado pelo Comitê de Ética do Instituto de Cardiologia/Fundação Universitária de Cardiologia sob o número de protocolo 2.699.665. O consentimento informado foi obtido de todos os participantes incluídos no estudo.

Os autores não utilizaram ferramentas de inteligência artificial no desenvolvimento deste trabalho.

Todo o conjunto de dados que dá suporte aos resultados deste estudo está disponível mediante solicitação ao autor correspondente.

O presente estudo não teve fontes de financiamento externas.

 10.36660/abc.20250145i Original Article Registry of Percutaneous Coronary Interventions in Very Small-Caliber Vessels: Analysis of a Sirolimus-Eluting Stent and Other Contemporary Drug-Eluting Stents 0000-0003-4198-2621 Slaviero João Vitor Conception and design of the research Acquisition of data Analysis and interpretation of the data Statistical analysis and Obtaining financing Writing of the manuscript Critical revision of the manuscript for content 1 Manica André Luiz Langer Conception and design of the research Writing of the manuscript Critical revision of the manuscript for content 1 0000-0002-9674-8528 Leite Rogério Eduardo Gomes Sarmento Conception and design of the research Analysis and interpretation of the data Critical revision of the manuscript for content 1 0009-0002-3237-0199 Borsa Eduarda Paiva Acquisition of data 2 0000-0003-2823-5365 Schmidt Marcia Moura 1 0009-0001-3986-4848 Ogando Rodrigo Campos Acquisition of data 3 Teixeira Julia Kurtz Conception and design of the research Acquisition of data Critical revision of the manuscript for content 1 0000-0002-7883-828X Guimarães Raphael Boesche 1 Azmus Alexandre Damiani Conception and design of the research Analysis and interpretation of the data Writing of the manuscript 1 Gottschall Carlos A. M. Critical revision of the manuscript for content 1 Brazil Instituto de Cardiologia, Porto Alegre, RS – Brazil Brazil Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS – Brazil Brazil Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS – Brazil João Vitor Slaviero • Instituto de Cardiologia – Avenida Princesa Isabel, 395. Postal Code 90040-371, Porto Alegre, RS – Brazil E-mail: slavierojv@gmail.com

No potential conflict of interest relevant to this article was reported.

Henrique Ribeiro

 Abstract Background

Percutaneous coronary intervention (PCI) in very small-caliber vessels (≤2.25 mm) presents technical challenges and is associated with poorer outcomes compared to larger vessels. The Inspiron® stent, a drug-eluting stent (DES) manufactured in Brazil, has been evaluated in multiple studies; however, data on its performance in vessels smaller than 2.5 mm are lacking.

 Objectives

This study aimed to evaluate the clinical outcomes of PCI using DES in very small-caliber vessels and to compare the Inspiron® stent with other contemporary DES platforms. The primary endpoint was major adverse cardiac events (MACE), defined as cardiac death, target lesion myocardial infarction, and clinically driven target lesion revascularization.

 Methods

We conducted an observational study including a consecutive sample at a Brazilian reference center from 2017 to 2021. Outcomes were assessed in-hospital, at 30 days, 6 months, and 12 months, using a 5% threshold for statistical significance.

 Results

A total of 783 DES were implanted: 47% Inspiron® and 46.8% other DES. The mean patient age was 64.7 ± 11 years; 61% were male, and 42% had diabetes mellitus. At 12 months, the overall MACE rate was 4.54% (36/793), with no difference between groups (Inspiron®: 4.6% vs. other DES: 4.6%; p=1.000). Individual endpoints and stent thrombosis rates were also similar (4 [1.0%] vs. 2 [0.5%]; p=0.868).

 Conclusion

our findings show that the Inspiron® stent has acceptable safety and efficacy and provides comparable 12-month clinical outcomes to other contemporary DES in very small-caliber coronary vessels.

Registry of Percutaneous Coronary Interventions in Very Small-Caliber Vessels: Analysis of a Sirolimus-Eluting Stent and Other Contemporary Drug-Eluting Stents TLR: Target lesion revascularization; Cardiac Mortality: Confirmed and probable cardiac mortality; MACE: Major Adverse Cardiovascular Events — cardiac mortality, target lesion myocardial infarction, and clinically driven target lesion revascularization.

Keywords Drug-Eluting Stents Sirolimus Percutaneous Coronary Intervention Coronary Artery Disease Sources of Funding:There were no external funding sources for this study. Introduction

Percutaneous coronary intervention (PCI) has grown increasingly complex due to advances in device technology, operator expertise, and procedural techniques.1,2 Small vessel disease (<2.75 mm) is present in up to 50% of PCI cases.3-5 The advent of 2.0 mm and 2.25 mm stents introduced the term “very small-caliber vessel”.6

PCI in small-caliber vessels presents significant challenges and is linked to higher risks of adverse cardiac events, including restenosis and stent thrombosis.4,7-16 These vessels often have diffused atherosclerotic disease requiring longer stents, which increases restenosis risk13 and limits the suitability for surgical revascularization.14-16

With numerous drug-eluting stent (DES) options available, research focuses on features that predict better outcomes. Thinner stent struts correlate with reduced thrombogenicity and shear stress,17-19 Meta-analyses suggest thinner struts may reduce stent thrombosis, myocardial infarction, and target lesion revascularization (TLR) risks, although these findings lack statistical significance. The type of drug eluted by the stent is another key factor. While DES generally exhibit a class effect in small vessels,20 Sirolimus-eluting DES have shown better outcomes for TLR and myocardial infarction, particularly in longer lesions.21

The Inspiron® stent, the first DES manufactured in Brazil, elutes Sirolimus, consists of cobalt-chromium alloy with 75 μm struts, and uses a biodegradable abluminal polymer, making it suitable for very small vessels. Although its safety and efficacy have been evaluated,17,18,22 no comparative data exist for vessels ≤2.25 mm vs. other contemporary DES.

Given the frequency of PCIs in these vessel sizes and widespread Inspiron® use, this study aims to analyze real-world outcomes of PCI with contemporary DES in very small-caliber coronary vessels.

 Methods Study design, setting, and population

This investigator-initiated, prospective observational study included a consecutive sample of patients aged over 18 years who were referred to the cardiac catheterization laboratory of a tertiary referral hospital in southern Brazil between 2017 and 2021. All patients underwent PCI of very small-caliber vessels using either the INSPIRON® stent or other contemporary DES. The indication for PCI was determined by the attending medical team for each patient. Patients with stents implanted in coronary lesions of larger calibers (≥2.5 mm), as well as those undergoing PCI without DES implantation, were excluded from this study.

Clinical data were collected from medical records, outpatient follow-up visits, and telephone contacts. Clinical outcomes were assessed during hospitalization and at 30 days, 6 months, and 12 months post-PCI. Repeat coronary angiography was performed only in patients with a clinical indication for invasive reassessment as determined by the attending physicians; routine angiographic or functional testing was not performed during follow-up.

The study protocol was approved by the Institutional Research and Ethics Committee of the hospital and was conducted in accordance with Resolution CNS 466/2012.

 Procedural aspects

All patients received dual antiplatelet therapy (DAPT) either before or immediately after the PCI procedure, and unfractionated heparin was administered during the intervention. The procedural strategy, including the choice and duration of DAPT, was determined by the attending medical team. Except in cases guided by intravascular imaging, the reference vessel diameter was estimated visually during angiography.

 Stents

All patients received at least one INSPIRON® or other DES. The choice of stent type was based on operator discretion and device availability at the center. The characteristics of the stents used are shown in Table 1.

– Drug-eluting stents used
Stent N (%) Material Strut Thickness Drug Polymer
Inspiron ® 392 (50.1%) Cobalt-Chromium 75μm Sirolimus Biodegradable
Resolute Onyx/ Integrity ® 218 (27.8%) Cobalt-Chromium 81/91μm Zotarolimus Durable
Promus ® 73 (9.7%) Platinum-Chromium 81μm Everolimus Biodegradable
Xience ® 37 (4.7%) Cobalt-Chromium 81μm Everolimus Durable
Synergy ® 30 (3.8%) Platinum-Chromium 74μm Everolimus Biodegradable
Orsiro ® 19 (2.4%) Cobalt-Chromium 60μm Sirolimus Biodegradable
Ultimaster ® 8 (1.0%) Cobalt-Chromium 80μm Sirolimus Biodegradable
Supraflex ® 6 (0.8%) Cobalt-Chromium 60 Sirolimus Biodegradable

Drug-eluting stents analyzed in the sample, presented in descending order of frequency, included the metallic scaffold material, strut thickness, eluted drug, and polymer type.

 Study endpoints

The primary endpoint was Major Adverse Cardiovascular Events (MACE), a composite of Cardiac Death, Target Lesion Myocardial Infarction, and Clinically Driven TLR. In addition, the individual components of the primary endpoint were analyzed, as well as the endpoint of Stent Thrombosis, defined as acute myocardial infarction associated with occlusion of a previously implanted 2.00 mm or 2.25 mm DES, classified as definite or confirmed stent thrombosis.20

The main study objective was to evaluate the overall composite endpoint in the sample and compare outcomes between INSPIRON® and other contemporary DES available at the center over a one-year follow-up period. Differences in MACE rates were compared according to strut thickness (<80 µm vs. >80 µm) and the type of drug eluted (Sirolimus vs. other agents).

Angiographic success of PCI was defined as residual stenosis <20% with TIMI 3 flow, without side-branch occlusion, flow-limiting dissection, distal embolization, or angiographic thrombus.21

 Statistical analysis

Data were analyzed using the IBM Statistical Package for the Social Sciences (SPSS), version 20.0. Categorical variables are presented as absolute numbers (n) and percentages (%), and continuous variables as mean ± standard deviation. The normality of distribution for continuous variables was assessed using the Kolmogorov–Smirnov test. Associations between categorical variables were tested using the Chi-square test, and differences in continuous variables were assessed with the unpaired Student’s t-test. A two-tailed p-value <0.05 was considered statistically significant. Survival curves were estimated using the Kaplan–Meier method, and group differences were compared using the log-rank test, adopting a 5% significance level.

 Study power

Given the available sample size of 391 and 392 patients per group, the study had over 80% power to detect differences of approximately six percentage points. Power calculations were performed using the WINPEPI software, version 11.65.

 Results

From January 2017 to December 2021, a total of 834 stents were implanted and included in the database. Of these, 783 (93.8%) stents met the inclusion criteria, were successfully implanted, and had at least 12 months of follow-up: 392 INSPIRON® stents (47%) and 391 “Other DES” (46.8%). These 834 stents were implanted in 762 patients (1.03 stent per patient). Seven stents (0.8%) were excluded from follow-up (four in the INSPIRON® group and three in the “Other DES” group, 1.02% vs. 0.76%, p=0.760) due to four cases of no-reflow, two cases of stent delivery failure due to severe proximal tortuosity and calcification, and one death caused by ventricular fibrillation during stent deployment (Figure 1).

– Flowchart.

The rates of hypertension, diabetes mellitus, active smoking, and dyslipidemia were similar between groups. Mean age was slightly higher in the “Other DES” group, reaching statistical significance, though the small numeric difference had no clinical impact on outcomes. Prior heart failure was more frequent in the INSPIRON® group, while acute coronary syndrome (ACS) accounted for 74.7% of the PCI indications, with unstable angina being the most common diagnosis (40.4%), significantly higher in the “Other DES” group. Other clinical characteristics are shown in Table 2.

– Clinical and Demographic Characteristics
Clinical and Demographic Characteristics Stents (n = 783) INSPIRON® (n = 392; 50%*) Other DES (n = 391; 50%*) p
Age (years) 64.7 63.3 ±10.98 66.13±11.15 0.001
BMI (kg/m2) 27.5 27.26 ±3.55 27.64 ±3.73 0.138
Male sex 480(61.3%) 227(47.2%) 253(52.8%) 0.060
Serum creatinine (mg/dL) 1.04 1.02 ±0.38 1.06±0.40 0.249
Hypertension 603(77%) 302 (50%) 301 (50%) 1.000
Family history of CAD 69 (8.8%) 37 (59.6%) 32 (46.4%) 0.622
Current smoker 293(37.4%) 156 (53.3%) 137 (46.7%) 0.193
Diabetes mellitus 329 (42%) 177(53.7%) 152 (46.3%) 0.088
Insulin-treated diabetes 92 (11.7%) 55 (59.7%) 37(40.3%) 0.091
Dyslipidemia 259(33.1%) 121 (46.7%) 138 (53.3%) 0.105
Heart failure (LVEF <50%) 48 (6.1%) 33 (68.7%) 15 (31.3%) 0.012
Previous stroke 27 (3.4%) 15 (55.5%) 12 (44.5%) 0.700
Previous myocardial infarction 121(15.5%) 64 (52.8%) 57(47.2%) 0.563
Previous PCI 162(20.7%) 73 (45%) 89 (55%) 0.180
Previous CABG 64 (8.2%) 34 (53.2%) 30 (46.8%) 0.703

Proportions refer to variables analyzed separately and not to the total sample size. DES: drug-eluting stents; BMI: body mass index; HTN: hypertension; CAD: coronary artery disease; DM: diabetes mellitus; HF-LVEF <50%: heart failure with left ventricular ejection fraction <50%; CVA: cerebrovascular accident; PCI: percutaneous coronary intervention; CABG: coronary artery bypass grafting.

INSPIRON® stents were more frequently implanted in the circumflex artery, right coronary artery, and posterior descending artery compared with the “Other DES” group. There were no significant differences between groups regarding stent length, access route, or percentage of pre-dilated lesions. PCIs using INSPIRON® stents showed lower rates of rotational atherectomy and intravascular ultrasound (IVUS) use, though absolute rates of these devices were very low, preventing correlation with events. Additional angiographic and procedural data are presented in Table 3.

– Angiographic and procedural characteristics
Variable Total (n = 783) INSPIRON® (n = 392; 50%*) Other DES (n = 391; 50%*) p
Target coronary vessel
Left anterior descending artery 293 (36%) 157 (53.5%) 136 (46.4%) 0.127
Left circumflex artery 139 (18%) 87 (62.5%) 52 (37.4%) 0.001
Right coronary artery 171 (22%) 102 (59.6%) 69 (40.3%) 0.004
Diagonal branch 68 (8.6%) 27 (39.7%) 33 (60.2%) 0.420
Obtuse marginal branch 70 (8.9 %) 41 (58.5%) 29 (41.4%) 0.132
Posterior descending artery 31 (3.9%) 22 (70.9%) 8 (29%) 0.009
Posterolateral branch 14 (1.7%) 8 (57.1%) 6 (42.8%) 0.546
Venous graft 7 (0.89%) 1 (14.3%) 6 (85.7%) 0.057
Clinical presentation
ST-elevation myocardial infarction (STEMI) 145(18.5%) 81 (55.8%) 64 (44.1%) 0.117
Non-ST-elevation myocardial infarction (NSTEMI) 124(15.8%) 74 (59.6%) 50 (40.3%) 0.180
Unstable angina 316(40.4%) 127 (40.1%) 189 (59.8%) 0.001
Stable angina 198(25.3%) 110 (55.5%) 88 (44.4%) 0.070
Functional assessment
Invasive physiology (FFR/iFR) 7 (0.89%) 1 (14.2%) 6 (85.7%) 0.057
Myocardial scintigraphy 18 (2.3%) 6 (33.3%) 12 (66.6%) 0.152
Stress echocardiography 1 (0.1%) 1 (100%) 0 (0%) 0.320
Exercise treadmill test 11 (1.4%) 5 (45.4%) 6 (54.5%) 0.860
Procedural aspects
Predilation 710(90%) 355 (50%) 355 (50%) 0.981
Thrombus aspiration 6 (0.8%) 4 (66.6%) 2 (33.3%) 0.412
Rotational atherectomy 9 (1.1%) 0 (0.0%) 9 (100%) 0.002
Intravascular ultrasound (IVUS) 8 (1.0%) 0 (0.0%) 8 (100%) 0.004
Postdilation 369(47.1%) 171 (46.3%) 198 (53.6%) 0.049
Radial arterial access 588(75.1%) 285 (48.4%) 303 (51.5%) 0.121
Femoral arterial access 195(24.9%) 98 (50.2%) 97 (49.7%) 0.950
Mean stent length (mm) 21.46 22.05±6.0mm 21.45±7.2mm 0.717
Stent diameter
- 2.0 mm 16 (2.0%) 4 (25%) 12 (75%) 0.068
- 2.25 mm 767 (97.9%) 386 (50.3%) 381 (49.6%) 0.862

*Proportions refer to variables analyzed separately and not to the total sample size. DES: drug-eluting stent; IVUS: intravascular ultrasound.

The overall MACE rate was 4.54% (36/793) and statistically equivalent between the compared groups (Table 4): 18 events in the INSPIRON® group and 18 in the “Other DES” group (Figure 2), as well as in each individual endpoint. he incidence of stent thrombosis was similar between stent types throughout all evaluated periods (Figure 3).

– Clinical Outcomes at 12-Month Follow-Up
Períod Group / Number of Stents In-Hospital 30 days 6 months 1 year
Inspiron® (n=392) Other DES (n=391) Inspiron® (n=392) Other DES (n=391) Inspiron® (n=392) Other DES (n=391) Inspiron® (n=392) Other DES (n=391)
MACE 0 (0%) 1(0.3%) 6(1.5%) 3 (0.8%) 10 (2.5%) 7(1.8%) 18(4.6%) 18(4.6%)
p p = 0.499 p = 0.505 p = 0.625 p = 1.000
Target Lesion Revascularization 0 (0%) 0 (0%) 1 (0.2%) 0 (0%) 2 (0.5%) 0 (0%) 4 (1.0%) 7 (1.8%)
p p = 1.000 p = 0.999 p = 0.499 p = 0.384
Target Lesion Myocardial Infarction 0 (0%) 1 (0.3%) 2(0.5%) 2(0.5%) 2(0.5%) 2(0.5%) 5(1.3%) 3(0.8%)
p p = 0.499 p = 1.000 p = 1.000 p = 0.725
Cardiac Mortality* 0 (0%) 0(0%) 3 (0.8%) 1 (0.3%) 6 (1.5%) 5(1.3%) 9(2.3%) 8(2.1%)
p p = 1.000 p = 0.624 p = 0.999 p = 0.999

MACE: Major Adverse Cardiovascular Events (composite of cardiac death, target lesion myocardial infarction, and clinically driven target lesion revascularization); TLR: Target Lesion Revascularization (clinically driven); Cardiac mortality: includes confirmed and probable cardiac deaths.

– MACE Events. Cumulative number of MACE (Major Adverse Cardiovascular Events — cardiac mortality, target lesion myocardial infarction, and clinically driven target lesion revascularization) during the follow-up periods for each stent group.

– Stent Thrombosis During the Evaluated Periods. Cumulative number of stent thrombosis events during the follow-up periods for each stent group.

The confirmed and probable cardiac mortality rate in the overall cohort was 2.14% (17/793), similar between study groups. Clinical follow-up was comparable across groups, with a loss to follow-up of 42 patients (5.5%) over one year.

During a one-year follow-up, event-free survival curves were similar (Figure 4). At 6- and 12-month follow-up, both groups maintained comparable DAPT use (Table 6)..

– Kaplan-Meier Curve. Kaplan-Meier cumulative survival curve free from MACE (Major Adverse Cardiovascular Events — cardiac mortality, target lesion myocardial infarction, and clinically driven target lesion revascularization) during the 365-day follow-up period.

– Antiplatelet Medical Therapy
*Antiplatelet Therapy at 6 Months, n (%) ** INSPIRON® (382/ 392) Other DES (383/ 391) p
Aspirin 364 (95.2%) 369 (96.3%) 0.242
ADP Inhibitors
Clopidogrel 356 (93.1%) 362 (94.5%) 0.323
Prasugrel 7 (1.8%) 3 (0.7%) 0.201
Ticagrelor 1 (0.2%) 0 (0%) 0.317
None 7 (1.8%) 8 (2.0%) 0.798
Any ADP inhibitor† 371 (97.1%) 373 (97.3%) 0.820
*Antiplatelet Therapy at 1 Year, n (%) ** INSPIRON® (374/ 392) Other DES (375/ 391) p
Aspirin 357 (95.4%) 355 (94.6%) 0.561
Any ADP nhibitor† 337 (90.1%) 332 (88.5%) 0.469

*: Number of stents in each group, excluding deaths during the corresponding follow-up period. †Number of patients receiving any ADP inhibitor (Clopidogrel, Prasugrel, or Ticagrelor). ADP: adenosine diphosphate; DES: drug-eluting stent.

The incidence of stent thrombosis was similar between stent types throughout all evaluated periods (Table 5). At 6- and 12-month follow-up, both groups maintained comparable DAPT use (Table 6).

– Stent Thrombosis
Period Type of Stent, n (%) Intra-hospitalar 30 days 6 months 1 year
Inspiron® Others Inspiron® Others Inspiron® Others Inspiron® Others
Stent thrombosis* 0 (0%) 1 (0.3%) 2 (0.5%) 2(0.5%) 2(0.5%) 2 (0.5%) 4(1.0%) 2(0.5%)
p p = 0.499 p = 1.000 p = 1.000 p = 0.868

Cumulative rate of stent thrombosis over follow-up periods. *Stent thrombosis: confirmed stent thrombosis.

 Discussion

This contemporary real-world registry, which evaluated Brazilian clinical data from patients undergoing PCI with stent implantation in very small-caliber vessels, demonstrated low MACE rates and comparable outcomes among the different available stent platforms (Central Illustration), consistent with data from previous literature.23,24

The presence of diabetes mellitus is often associated with diffuse atherosclerotic coronary disease in small vessels and is considered a predictor of restenosis and stent thrombosis after PCI with DES.25-35 In our sample, among the stents associated with MACE, 42% (15/36) were implanted in patients with known diabetes mellitus — the same proportion as in the overall cohort. Most patients undergoing PCI required stents longer than 20 mm; however, the mean stent length was not greater among those associated with MACE compared with event-free stents (21.98 mm vs. 21.43 mm, p=0.820). Although certain clinical characteristics differed between groups, analysis of MACE for INSPIRON® vs. “Other DES” showed no significant difference among patients with heart failure and reduced ejection fraction (<50%) (4/18 [22%] vs. 3/18 [17%], p=0.67) or those presenting with acute coronary syndromes (8/18 [44.4%] vs. 9/18 [50%], p=0.74). The small number of events during follow-up precluded multivariate analysis of other clinical and procedural variables.

The potential benefit of thinner stent struts, which may cause less endothelial injury, was evaluated in our cohort when comparing DES with <80 µm vs. >80 µm strut thickness. Although no statistical significance was found between INSPIRON® and other DES (48% vs. 52%, p=1.010), it is plausible that a larger sample or studies including routine angiographic follow-up might detect differences, as the occurrence of acute or chronic ischemic symptoms — the main indication for invasive re-evaluation — may have been underestimated due to the small myocardial territory at risk.

When analyzing results by eluted drug, our data demonstrate statistical equivalence in MACE between Sirolimus-eluting stents (INSPIRON®) and devices eluting other agents, suggesting a class effect among currently available DES, in line with existing evidence.36-39 These findings also indicate that engineering and biochemical characteristics of contemporary DES platforms may mitigate the relative importance of the specific drug used.

The use of intravascular imaging (particularly IVUS) improves acute and long-term angiographic and clinical outcomes.40-43 However, its use in our sample was very limited — only 1% (8/783) of cases — since most procedures were performed in public health system patients, where this technology is not routinely funded. Moreover, IVUS use in vessels <2.25 mm can be technically challenging and may increase the risk of iatrogenic plaque injury,41 which might have influenced operator decisions.

The diffuse distribution pattern of stent thrombosis events observed in our registry suggests that acute procedural factors such as stent underexpansion or significant coronary dissection were not major contributors to adverse outcomes Table 5.

DAPT use and duration were similar between groups throughout follow-up, with a high maintenance rate of DAPT at 12 months, which may have influenced the low event frequency (Table 6).

This study has limitations inherent to nonrandomized designs and device availability at the time of PCI. Restenosis might have been underdiagnosed due to the absence of routine angiographic follow-up; however, late restenosis (>12 months) is usually more related to atherosclerotic progression than to the previous PCI. Grouping different DES solely by strut thickness or drug elution may not be entirely appropriate, as other design factors — such as strut geometry, connection morphology, and polymer degradation — may also influence outcomes. Nevertheless, this study represents a significant real-world sample from a high-volume tertiary center, with broad inclusion criteria and clinically relevant findings.

The emergence of drug-eluting balloons (DEB) has introduced a rational alternative for avoiding metallic scaffolds.23,24,44,45 Comparative studies between new-generation DES and DEB in de novo lesions of very small-caliber vessels (<2.5 mm), similar to those in our study, are essential to determine the optimal therapeutic approach for these patients.

 Conclusion

PCI in very small-caliber vessels using contemporary DES demonstrates satisfactory clinical outcomes at 12-month follow-up, supporting the continued use of this therapeutic strategy and of the evaluated stent platforms.

This article is part of the thesis of master submitted by João Vitor Slaviero, from Instituto de Cardiologia de Porto Alegre.

This study was approved by the Ethics Committee of the Instituto de Cardiologia/Fundação Universitária de Cardiologia under the protocol number 2.699.665. Informed consent was obtained from all participants included in the study.

The authors did not use any artificial intelligence tools in the development of this work.

All datasets supporting the results of this study are available upon request from the corresponding author

There were no external funding sources for this study.