Arq Bras Cardiol abc Arquivos Brasileiros de Cardiologia Arq. Bras. Cardiol. 0066-782X 1678-4170 Sociedade Brasileira de Cardiologia - SBC 8Mk8z5WkT67qf6GPhtnDjQz S0066-782X2026000201005 01005 10.36660/abc.20260140 Minieditorial Ressonância Magnética Cardíaca e Histologia na Valvopatia Aórtica: Convergências e Limitações 0000-0002-6571-5037 Gomes Helder Jorge Andrade 1 2 3 0000-0002-6728-3565 Senra Tiago 2 4 Faculdade de Medicina de Jundiaí Jundiaí SP Brasil Faculdade de Medicina de Jundiaí, Jundiaí, SP – Brasil Vera Cruz Hospital Campinas SP Brasil Vera Cruz Hospital, Campinas, SP – Brasil ICON Diagnósticos por Imagem Jundiaí SP Brasil ICON Diagnósticos por Imagem, Jundiaí, SP – Brasil Instituto Dante Pazzanese de Cardiologia São Paulo SP Brasil Instituto Dante Pazzanese de Cardiologia, São Paulo, SP – Brasil Helder Jorge Andrade Gomes • Faculdade de Medicina de Jundiaí – R. Francisco Teles, 250. CEP 13202-550, Jundiaí, SP – Brasil E-mail: helderjorge@hotmail.com 22 05 2026 2026 123 2 e20260140 22 02 2026 04 03 2026 04 03 2026 This is an open-access article distributed under the terms of the Creative Commons Attribution License Palavras-chave Imageamento por Ressonância Magnética Fibrosis Valvopatia Aórtica

A fibrose miocárdica constitui elemento central do remodelamento ventricular na valvopatia aórtica grave e associa-se à disfunção ventricular e a piores desfechos, inclusive após intervenção valvar.1-3 Embora a fração do volume de colágeno obtida por histologia represente o padrão-ouro para quantificação da fibrose intersticial, a biópsia miocárdica não integra a prática clínica rotineira devido ao seu caráter invasivo e às limitações amostrais. Nesse contexto, a ressonância magnética cardíaca (RMC) se consolidou como método não invasivo para caracterização tecidual, permitindo identificar fibrose regional por meio do realce tardio e estimar expansão intersticial por meio do mapeamento T1 e do cálculo do volume extracelular (VEC).4-7

O estudo publicado nesta edição dos Arquivos Brasileiros de Cardiologia contribui de forma relevante ao comparar diretamente parâmetros de RMC com a fração do volume de colágeno obtida por biópsia miocárdica em 108 pacientes com valvopatia aórtica grave submetidos à cirurgia.8 Diferentemente de muitas séries anteriores compostas exclusivamente por estenose aórtica, a coorte incluiu também pacientes com insuficiência aórtica, ampliando a aplicabilidade dos achados e incorporando um espectro fisiopatológico mais abrangente de sobrecarga ventricular.

Os autores demonstram que tanto o realce tardio quanto o VEC global médio apresentaram correlação moderada com a fibrose histológica no septo interventricular. O realce tardio exibiu melhor desempenho diagnóstico global, com maior acurácia e área sob a curva ROC superior à do VEC. Este último apresentou sensibilidade limitada para identificação de maior carga fibrótica definida pela mediana da fração de colágeno, além de baixa concordância com a histologia.

Esses achados reforçam que os métodos não são equivalentes e provavelmente captam dimensões distintas do processo fibrótico. O realce tardio depende da diferença relativa de sinal entre miocárdio normal e áreas com maior acúmulo de colágeno, sendo mais sensível à fibrose focal ou substitutiva. Já o VEC reflete a expansão do compartimento extracelular, que pode decorrer não apenas da deposição de colágeno, mas também de inflamação, remodelamento intersticial heterogêneo ou infiltração, como ocorre na amiloidose – condição que pode coexistir em pacientes idosos valvopatas graves.9 Ainda que o VEC sofra menor influência de diversos fatores do que o valor de T1 nativo, como idade, sexo, frequência cardíaca, sequência de pulso utilizada, força e homogeneidade do campo magnético do aparelho de ressonância, cabe ressaltar que ainda não há na literatura consenso sobre qual seria o valor normal de VEC miocárdico. Assim, a correlação apenas moderada entre imagem e histologia provavelmente traduz a complexidade biológica do fenômeno, e não necessariamente limitação técnica isolada.

Outro aspecto relevante diz respeito à distribuição espacial da fibrose. A fibrose na valvopatia aórtica apresenta distribuição espacial variável e não restrito ao septo interventricular.2,10 A comparação escolhida pelos autores entre método global de avaliação da fibrose miocárdica e amostras histológicas focais envolve limitações inerentes de representatividade. Ainda assim, o estudo demonstra que a RMC é capaz de identificar de forma consistente a presença de remodelamento fibrótico relevante, mesmo que não reproduza com precisão absoluta a quantificação histológica.

Do ponto de vista clínico, o realce tardio já demonstrou associação prognóstica consistente em pacientes com estenose aórtica e permanece marcador consolidado de fibrose estabelecida.2,3 O VEC, por sua vez, tem se mostrado associado ao prognóstico em pacientes com estenose aórtica moderada ou importante, inclusive assintomáticos, sugerindo potencial papel na estratificação mais precoce.11 Além disso, evidências recentes indicam que o VEC apresenta redução após a intervenção cirúrgica ou percutânea na estenose aórtica, o que abre perspectiva para sua utilização na definição do melhor momento para intervenção.12

Entretanto, a integração entre realce tardio e VEC pode oferecer visão mais abrangente do processo fibrótico na doença valvar, captando tanto componentes regionais quanto intersticiais, mas ainda não integra o estadiamento proposto por sociedades internacionais – particularmente quanto ao momento ideal de intervenção – campo que permanece em evolução.

Ao correlacionar histologia e RMC em uma coorte cirúrgica que incluiu tanto estenose quanto insuficiência aórtica, o estudo amplia a compreensão sobre convergências e limites entre métodos invasivos e não invasivos na avaliação da fibrose miocárdica. Seus achados reforçam que a fibrose na valvopatia aórtica é fenômeno multifacetado e que sua caracterização por imagem deve ser interpretada de forma contextualizada. A consolidação do papel prognóstico desses marcadores e sua eventual incorporação na tomada de decisão terapêutica representam o próximo desafio na abordagem da valvopatia aórtica.

Minieditorial referente ao artigo: Análise da Fibrose Miocárdica Intersticial por Histologia e Ressonância Magnética na Valvopatia Aórtica de Grau Importante

 Referências Hein S Arnon E Kostin S Schönburg M Elsässer A Polyakova V Progression from Compensated Hypertrophy to Failure in the Pressure-Overloaded Human Heart: Structural Deterioration and Compensatory Mechanisms Circulation 2003 107 7 984 991 10.1161/01.cir.0000051865.66123.b7 1 Hein S, Arnon E, Kostin S, Schönburg M, Elsässer A, Polyakova V, et al. Progression from Compensated Hypertrophy to Failure in the Pressure-Overloaded Human Heart: Structural Deterioration and Compensatory Mechanisms. Circulation. 2003;107(7):984-91. doi: 10.1161/01.cir.0000051865.66123.b7. Weidemann F Herrmann S Störk S Niemann M Frantz S Lange V Impact of Myocardial Fibrosis in Patients with Symptomatic Severe Aortic Stenosis Circulation 2009 120 7 577 584 10.1161/CIRCULATIONAHA.108.847772 2 Weidemann F, Herrmann S, Störk S, Niemann M, Frantz S, Lange V, et al. Impact of Myocardial Fibrosis in Patients with Symptomatic Severe Aortic Stenosis. Circulation. 2009;120(7):577-84. doi: 10.1161/CIRCULATIONAHA.108.847772. Azevedo CF Nigri M Higuchi ML Pomerantzeff PM Spina GS Sampaio RO Prognostic Significance of Myocardial Fibrosis Quantification by Histopathology and Magnetic Resonance Imaging in Patients with Severe Aortic Valve Disease J Am Coll Cardiol 2010 56 4 278 287 10.1016/j.jacc.2009.12.074 3 Azevedo CF, Nigri M, Higuchi ML, Pomerantzeff PM, Spina GS, Sampaio RO, et al. Prognostic Significance of Myocardial Fibrosis Quantification by Histopathology and Magnetic Resonance Imaging in Patients with Severe Aortic Valve Disease. J Am Coll Cardiol. 2010;56(4):278-87. doi: 10.1016/j.jacc.2009.12.074. Rittié L Method for Picrosirius Red-Polarization Detection of Collagen Fibers in Tissue Sections Methods Mol Biol 2017 1627 395 407 10.1007/978-1-4939-7113-8_26 4 Rittié L. Method for Picrosirius Red-Polarization Detection of Collagen Fibers in Tissue Sections. Methods Mol Biol. 2017;1627:395-407. doi: 10.1007/978-1-4939-7113-8_26. Kim RJ Fieno DS Parrish TB Harris K Chen EL Simonetti O Relationship of MRI Delayed Contrast Enhancement to Irreversible Injury, Infarct Age, and Contractile Function Circulation 1999 100 19 1992 2002 10.1161/01.cir.100.19.1992 5 Kim RJ, Fieno DS, Parrish TB, Harris K, Chen EL, Simonetti O, et al. Relationship of MRI Delayed Contrast Enhancement to Irreversible Injury, Infarct Age, and Contractile Function. Circulation. 1999;100(19):1992-2002. doi: 10.1161/01.cir.100.19.1992. Messroghli DR Radjenovic A Kozerke S Higgins DM Sivananthan MU Ridgway JP Modified Look-Locker Inversion Recovery (MOLLI) for High-Resolution T1 Mapping of the Heart Magn Reson Med 2004 52 1 141 146 10.1002/mrm.20110 6 Messroghli DR, Radjenovic A, Kozerke S, Higgins DM, Sivananthan MU, Ridgway JP. Modified Look-Locker Inversion Recovery (MOLLI) for High-Resolution T1 Mapping of the Heart. Magn Reson Med. 2004;52(1):141-6. doi: 10.1002/mrm.20110. Wong TC Piehler K Meier CG Testa SM Klock AM Aneizi AA Association between Extracellular Matrix Expansion Quantified by Cardiovascular Magnetic Resonance and Short-Term Mortality Circulation 2012 126 10 1206 1216 10.1161/CIRCULATIONAHA.111.089409 7 Wong TC, Piehler K, Meier CG, Testa SM, Klock AM, Aneizi AA, et al. Association between Extracellular Matrix Expansion Quantified by Cardiovascular Magnetic Resonance and Short-Term Mortality. Circulation. 2012;126(10):1206-16. doi: 10.1161/CIRCULATIONAHA.111.089409. Bello JHSM Car LMMF Fonseca RA Lima GN Pires LJT Rosa VEE Interstitial Myocardial Fibrosis Analysis by Histology and Cardiac Magnetic Resonance in Severe Aortic Valve Disease Arq Bras Cardiol 2026 123 2 e20250203 https://doi.org/10.36660/abc.20250203i 8 Bello JHSM, Car LMMF, Fonseca RA, Lima GN, Pires LJT, Rosa VEE, et al. Interstitial Myocardial Fibrosis Analysis by Histology and Cardiac Magnetic Resonance in Severe Aortic Valve Disease. Arq Bras Cardiol. 2026; 123(2):e20250203. doi: https://doi.org/10.36660/abc.20250203i. Treibel TA López B González A Menacho K Schofield RS Ravassa S Reappraising Myocardial Fibrosis in Severe Aortic Stenosis: An Invasive and Non-Invasive Study in 133 Patients Eur Heart J 2018 39 8 699 709 10.1093/eurheartj/ehx353 9 Treibel TA, López B, González A, Menacho K, Schofield RS, Ravassa S, et al. Reappraising Myocardial Fibrosis in Severe Aortic Stenosis: An Invasive and Non-Invasive Study in 133 Patients. Eur Heart J. 2018;39(8):699-709. doi: 10.1093/eurheartj/ehx353. Nigri M Azevedo CF Rochitte CE Schraibman V Tarasoutchi F Pommerantzeff PM Contrast-Enhanced Magnetic Resonance Imaging Identifies Focal Regions of Intramyocardial Fibrosis in Patients with Severe Aortic Valve Disease: Correlation with Quantitative Histopathology Am Heart J 2009 157 2 361 368 10.1016/j.ahj.2008.09.012 10 Nigri M, Azevedo CF, Rochitte CE, Schraibman V, Tarasoutchi F, Pommerantzeff PM, et al. Contrast-Enhanced Magnetic Resonance Imaging Identifies Focal Regions of Intramyocardial Fibrosis in Patients with Severe Aortic Valve Disease: Correlation with Quantitative Histopathology. Am Heart J. 2009;157(2):361-8. doi: 10.1016/j.ahj.2008.09.012. Lee HJ Singh A Lim J Craig N Bing R Tastet L Diffuse Interstitial Fibrosis of the Myocardium Predicts Outcome in Moderate and Asymptomatic Severe Aortic Stenosis JACC Cardiovasc Imaging 2025 18 2 180 191 10.1016/j.jcmg.2024.08.003 11 Lee HJ, Singh A, Lim J, Craig N, Bing R, Tastet L, et al. Diffuse Interstitial Fibrosis of the Myocardium Predicts Outcome in Moderate and Asymptomatic Severe Aortic Stenosis. JACC Cardiovasc Imaging. 2025;18(2):180-91. doi: 10.1016/j.jcmg.2024.08.003. Bennett J Thornton GD Nitsche C Gama FF Aziminia N Gul U Left Ventricular Hypertrophy in Aortic Stenosis: Early Cell and Matrix Regression 2 Months Post-Aortic Valve Replacement Circ Cardiovasc Imaging 2024 17 12 e017425 10.1161/CIRCIMAGING.124.017425 12 Bennett J, Thornton GD, Nitsche C, Gama FF, Aziminia N, Gul U, et al. Left Ventricular Hypertrophy in Aortic Stenosis: Early Cell and Matrix Regression 2 Months Post-Aortic Valve Replacement. Circ Cardiovasc Imaging. 2024;17(12):e017425. doi: 10.1161/CIRCIMAGING.124.017425. 10.36660/abc.20260140i Short Editorial Cardiac Magnetic Resonance Imaging and Histology in Aortic Valve Disease: Convergences and Limitations 0000-0002-6571-5037 Gomes Helder Jorge Andrade 1 2 3 0000-0002-6728-3565 Senra Tiago 2 4 Jundiaí SP Brazil Faculdade de Medicina de Jundiaí, Jundiaí, SP – Brazil Campinas SP Brazil Vera Cruz Hospital, Campinas, SP – Brazil Jundiaí SP Brazil ICON Diagnósticos por Imagem, Jundiaí, SP – Brazil São Paulo SP Brazil Instituto Dante Pazzanese de Cardiologia, São Paulo, SP – Brazil Helder Jorge Andrade Gomes • Faculdade de Medicina de Jundiaí – R. Francisco Teles, 250. Postal Code 13202-550, Jundiaí, SP – Brazil E-mail: helderjorge@hotmail.com Keywords Magnetic Resonance Imaging Fibrosis Aortic Valve Disease

Myocardial fibrosis is a central element of ventricular remodeling in severe aortic valve disease and is associated with ventricular dysfunction and worse outcomes, even after valve intervention.1-3 Although the collagen volume fraction obtained by histology represents the gold standard for quantifying interstitial fibrosis, myocardial biopsy is not part of routine clinical practice due to its invasive nature and sample limitations. In this context, cardiac magnetic resonance imaging (CMR) has become established as a non-invasive method for tissue characterization, allowing the identification of regional fibrosis through late enhancement and the estimation of interstitial expansion through T1 mapping and calculation of extracellular volume (ECV).4-7

The study published in this issue of the Arquivos Brasileiros de Cardiologia makes a significant contribution by directly comparing CMR parameters with the collagen volume fraction obtained by myocardial biopsy in 108 patients with severe aortic valve disease who underwent surgery.8 Unlike many previous series composed exclusively of aortic stenosis, this cohort also included patients with aortic insufficiency, broadening the applicability of the findings and incorporating a more comprehensive pathophysiological spectrum of ventricular overload.

The authors demonstrate that both late gadolinium enhancement and mean global ECV showed a moderate correlation with histological fibrosis in the interventricular septum. Late gadolinium enhancement exhibited better overall diagnostic performance, with greater accuracy and an area under the ROC curve superior to that of ECV. The latter showed limited sensitivity for identifying higher fibrotic burden defined by the median collagen fraction, in addition to low concordance with histology.

These findings reinforce that the methods are not equivalent and likely capture distinct dimensions of the fibrotic process. Late enhancement depends on the relative signal difference between normal myocardium and areas with greater collagen accumulation, being more sensitive to focal or replacement fibrosis. ECV reflects the expansion of the extracellular compartment, which can result not only from collagen deposition but also from inflammation, heterogeneous interstitial remodeling, or infiltration, as occurs in amyloidosis – a condition that can coexist in elderly patients with severe valvular heart disease.9 Although ECV is less influenced by several factors than the native T1 value, such as age, sex, heart rate, pulse sequence used, strength, and homogeneity of the magnetic field of the MRI machine, it should be noted that there is still no consensus in the literature on what the normal value of myocardial ECV would be. Thus, the only moderate correlation between imaging and histology likely reflects the biological complexity of the phenomenon, and not necessarily an isolated technical limitation.

Another relevant aspect concerns the spatial distribution of fibrosis. Fibrosis in aortic valve disease presents a variable spatial distribution and is not restricted to the interventricular septum.2,10 The comparison chosen by the authors between a global method of assessing myocardial fibrosis and focal histological samples involves inherent limitations of representativeness. Even so, the study demonstrates that CMR can consistently identify the presence of relevant fibrotic remodeling, even if it does not reproduce the histological quantification with absolute precision.

From a clinical standpoint, late gadolinium enhancement has already demonstrated a consistent prognostic association in patients with aortic stenosis and remains a consolidated marker of established fibrosis.2,3 The ECV, in turn, has been shown to be associated with prognosis in patients with moderate or severe aortic stenosis, including asymptomatic patients, suggesting a potential role in earlier stratification.11 Furthermore, recent evidence indicates that ECV decreases after surgical or percutaneous intervention in aortic stenosis, which opens up perspectives for its use in defining the best time for intervention. 12

However, the integration between late gadolinium enhancement and ECV can offer a more comprehensive view of the fibrotic process in valvular heart disease, capturing both regional and interstitial components, but it does not yet integrate the staging proposed by international societies – particularly regarding the ideal timing of intervention – a field that remains under evolution.

By correlating histology and CMR in a surgical cohort that included both aortic stenosis and aortic insufficiency, the study broadens the understanding of convergences and limitations between invasive and non-invasive methods in the evaluation of myocardial fibrosis. Its findings reinforce that fibrosis in aortic valve disease is a multifaceted phenomenon and that its characterization by imaging should be interpreted contextually. The consolidation of the prognostic role of these markers and their eventual incorporation into therapeutic decision-making represent the next challenge in the approach to aortic valve disease.

Short Editorial related to the article: Interstitial Myocardial Fibrosis Analysis by Histology and Cardiac Magnetic Resonance in Severe Aortic Valve Disease