Arq Bras CardiolabcArquivos Brasileiros de CardiologiaArq. Bras. Cardiol.0066-782X1678-4170Sociedade Brasileira de Cardiologia - SBCK4fw6RnQTPYnW7KyRNzQzPnS0066-782X201800180079410.5935/abc.20180237Short EditorialMyocardial Perfusion Scintigraphy after Percutaneous Coronary Intervention in Asymptomatic Patients: Useful or Futile?GrossmanGabriel Blacher12Hospital Moinhos de VentoPorto AlegreRSBrazilHospital Moinhos de Vento, Porto Alegre, RS - BrazilInstituto de CardiologiaPorto AlegreRSBrazilCardionuclear - Instituto de Cardiologia, Porto Alegre, RS - BrazilMailing Address: Gabriel Blacher Grossman Rua Ramiro Barcelos, 910/201. Postal Code 90035-001, Moinhos de Vento, Porto Alegre, RS - Brazil E-mail: ggrossman@cardiol.br, ggrossman@terra.com.br1220181116794795This is an Open Access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.KeywordsCoronary Artery Disease/radionuclide imagingMyocardial RevascularizationPercutaneous Coronary InterventionMyocardial Ischemia
Myocardial perfusion scintigraphy (MPS) is a well-established non-invasive method for the evaluation of patients with suspected ischemic heart disease or with coronary artery disease (CAD).1 Its major diagnostic indication is in the assessment of patients with intermediate likelihood of CAD,2 with the diagnostic value being difficult to be dissociated from the prognostic information obtained with the method. Through several criteria validated in the literature, such as the extent of ischemia, the patient's risk of presenting cardiovascular events in the future3 can be assessed. In patients with established CAD, MPS has an important role in the evaluation of symptoms suggestive of myocardial ischemia, and can also assess the risk of non-fatal myocardial infarction and cardiac death. Although the value of quantification of ischemia has been the subject of debate in recent years, it is undeniable that in clinical practice it can assist in therapeutic decision-making.4,5
MPS may be useful in the evaluation of patients undergoing surgical or percutaneous revascularization procedures, especially if the patient has symptoms. Although MPS can be indicated in asymptomatic patients after 2 years of percutaneous coronary intervention (PCI) or 5 years of surgical procedure,6 few studies in the literature have analyzed the adequate time to perform the functional study in asymptomatic patients, and the clinical impact of this information. Cardiologic practice often contradicts what is recommended, and it is not uncommon to evaluate asymptomatic patients in a shorter period than that suggested in the literature.
In this edition of the Arquivos Brasileiros de Cardiologia, de Andrade et al.7 evaluated the prognostic value and clinical use of MPS in asymptomatic patients after PCI.7 The authors conducted a retrospective study evaluating 647 patients that were submitted to MPS after PCI. Fifty three percent of the patients presented abnormal MPS (30% abnormal with ischemia and 23% abnormal without ischemia). The annual rate of death was higher in those with abnormal perfusion without ischemia compared to the groups with ischemia and with normal MPS (3.3% x 2% x 1.2%, p = 0,021). The annual revascularization rate was 10.3% in the group with ischemia, 3.7% in those with normal MPS, and 3% in the group with abnormal MPS without ischemia. The independent predictors of mortality and revascularization were, respectively, a total perfusion defect greater than 6%, and an ischemic defect greater than 3%. Forty-two percent of the patients underwent MPS less than 2 years after PCI, and no significant differences were observed in relation to those who underwent it after this period.
The presence of silent ischemia in patients undergoing PCI is not uncommon, and is usually related to persistent or progressive CAD in remote vessels, rather than in the treated vessels.8,9 The study by de Andrade et al.7 demonstrated that 30% of the patients had silent ischemia, and that the 2-year period did not influence the power of MPS to predict events. However, there are no data in the literature demonstrating consistently that the diagnosis of ischemia after PCI modifies clinical outcomes.ISCHEMIA trial was designed to determine the value of the quantification of ischemia through non-invasive methods, and whether an invasive management strategy improves clinical outcomes when added to optimal medical therapy in patients with CAD and moderate or severe ischemia, but the results are not yet known.10 In the light of current knowledge, the presence of ischemia detected by MPS is an excellent cardiovascular risk marker, and can be a gatekeeper for invasive management strategy. In patients undergoing PCI, particularly if CAD was not fully revascularized, or if the patient did not present angina as a manifestation of CAD, MPS before the time suggested in the literature may be useful and not futile. It is up to the attending physician to consider whether the time suggested in the literature should be waited to reassess the asymptomatic patient after PCI, since the data to support this practice is not robust.
Short Editorial regarding the article: The Prognostic Value and Clinical Use of Myocardial Perfusion Scintigraphy in Asymptomatic Patients after Percutaneous Coronary Intervention
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Am Heart J. 2005;149(3):534-40.RajagopalVGurmHSBrunkenRCProthierEEBhattDLLauerMSPrediction of death or myocardial infarction by exercise single photon emission computed tomography perfusion scintigraphy in patients who have recent coronary artery stentingAm Heart J200514935345409 Zellweger MJ, Fahrni G, Ritter M, Jeger RV, Wild D, Buser PM, et al; BASKET Investigators. Prognostic value of "routine" cardiac stress imaging 5 years after percutaneous coronary intervention: the prospective long-term observational BASKET (Basel Stent Kosteneffektivitäts Trial) LATE IMAGING Study. JACC Cardiovasc Interv. 2014;7(6):615-21.ZellwegerMJFahrniGRitterMJegerRVWildDBuserPMBASKET InvestigatorsPrognostic value of "routine" cardiac stress imaging 5 years after percutaneous coronary intervention the prospective long-term observational BASKET (Basel Stent Kosteneffektivitäts Trial) LATE IMAGING StudyJACC Cardiovasc Interv20147661562110 Maron DJ, Hochman JS, O'Brien SM et al. International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) trial: Rationale and design. Am Heart J. 2018; 201:124-35.MaronDJHochmanJSO'BrienSMInternational Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) trial Rationale and designAm Heart J2018201124135MinieditorialCintilografia Miocárdica após Revascularização Percutânea em Pacientes Assintomáticos: Futilidade ou tem Utilidade?GrossmanGabriel Blacher12Hospital Moinhos de Vento, Porto Alegre, RS - BrasilCardionuclear - Instituto de Cardiologia, Porto Alegre, RS - BrasilCorrespondência: Gabriel Blacher Grossman Rua Ramiro Barcelos, 910/201. CEP 90035-001, Moinhos de Vento, Porto Alegre, RS - Brasil E-mail: ggrossman@cardiol.br, ggrossman@terra.com.brPalavras-chaveDoença da Artéria Coronariana/cintilografiaRevascularização MiocárdicaIntervenção Coronária Percutâneaisquemia miocárdica
A cintilografia miocárdica (CM) é um método não invasivo consagrado na prática clínica para a avaliação de pacientes com suspeita de cardiopatia isquêmica ou com doença arterial coronariana (DAC) estabelecida.1 Na avaliação diagnóstica encontra sua principal indicação na investigação de pacientes com probabilidade pré-teste intermediária de DAC,2 sendo difícil dissociar o valor diagnóstico da informação prognóstica obtida com o método. Por meio de critérios de gravidade validados na literatura, como a extensão da isquemia, podemos determinar o risco de o paciente apresentar eventos cardiovasculares no futuro.3 Nos pacientes com DAC estabelecida, a CM pode auxiliar na estratificação de risco para eventos como infarto do miocárdio não fatal e morte cardíaca, bem como na avaliação de sintomas sugestivos de isquemia miocárdica. Embora o valor da quantificação de isquemia tenha sido tema de debate nos últimos anos, é inegável que na prática clínica pode auxiliar na tomada da decisão terapêutica.4,5
A CM pode ser útil na avaliação de pacientes submetidos a procedimento de revascularização cirúrgica ou percutânea, principalmente se o paciente apresentar sintomas. Embora a realização de CM possa ser indicada em pacientes assintomáticos após 2 anos da intervenção coronariana percutânea (ICP) ou após 5 anos do procedimento cirúrgico,6 poucos estudos na literatura analisaram o tempo adequado para a realização do estudo funcional em pacientes assintomáticos e a validade da realização do mesmo. A prática cardiológica contradiz frequentemente o que é recomendado, não sendo rara a avaliação de pacientes assintomáticos em um período menor do que é sugerido na literatura.
Nesta edição dos Arquivos Brasileiros de Cardiologia, de Andrade et al.,7 avaliaram o valor prognóstico e o uso clínico da cintilografia de perfusão miocárdica em pacientes assintomáticos após ICP.7 Os autores realizaram um estudo retrospectivo avaliando 647 pacientes que realizaram CM após ICP. Cinquenta e três por cento dos pacientes apresentaram CM anormal (30% anormais com isquemia e 23% anormais sem isquemia). A taxa anual de óbitos foi superior naqueles com perfusão anormal sem isquemia comparada nos grupos com isquemia e CM normal (3,3% X 2% X 1,2%, p = 0,021). A taxa anual de revascularização foi de 10,3% no grupo com isquemia, 3,7% naquelas com CM normal e 3% no grupo com CM anormal sem isquemia. Foram preditores independentes de mortalidade e revascularização, respectivamente, defeito perfusional maior do que 6% e defeito isquêmico maior que 3%. Quarenta e dois por cento dos pacientes realizaram CM menos de 2 anos após o procedimento de ICP e não foram observadas diferenças relevantes em relação aos que realizaram após este período.
A presença de isquemia silenciosa nos pacientes submetidos à ICP não é incomum, e usualmente está relacionada à evolução da DAC em territórios remotos e não nas áreas revascularizadas.8,9 O estudo de de Andrade et al.7 demonstrou que 30% dos pacientes apresentavam isquemia mesmo não referindo sintomas e que o período de 2 anos não modifica de maneira relevante a informação obtida pela CM. Não existem dados na literatura que demonstrem consistentemente que o diagnóstico de isquemia após ICP modifique desfechos clínicos. O estudo ISCHEMIA foi delineado para determinar qual o valor da quantificação da isquemia por meio de métodos não invasivos e se esta informação apresenta interação com a decisão terapêutica e desfechos clínicos, mas seus resultados ainda não são conhecidos.10 À luz do conhecimento atual, a presença de isquemia detectada pela CM é sabidamente um marcador de risco cardiovascular e pode auxiliar na tomada de decisão terapêutica. Particularmente em pacientes submetidos à ICP, se a mesma foi realizada de maneira incompleta ou se o paciente não apresentou angina como manifestação de DAC, a realização de CM antes do tempo sugerido na literatura pode ser útil e não fútil. Cabe ao médico assistente considerar se deve esperar o tempo sugerido na literatura para reavaliar o paciente, pois a base teórica para esta conduta não apresenta respaldo consistente.
Minieditorial referente ao artigo: O Valor Prognóstico e o uso Clínico da Cintilografia de Perfusão Miocárdica em Pacientes Assintomáticos após Intervenção Coronariana Percutânea