Análise quantitativa da obstrução microvascular no infarto agudo do miocárdio pela ressonância magnética cardíaca: comparação entre as técnicas de perfusão de primeira passagem e de realce tardio miocárdico como preditores de remodelamento ventricular esquerdo

Abstract

Microvascular obstruction (MVO) is due to the presence of microcirculatory lesion caused by acute myocardial infarction or microembolization of fatty cells and debris after chemical or mechanical reperfusion of the coronary lesion. The diagnosis of MVO by the cardiac magnetic resonance imaging (CMR) is performed by first pass perfusion (FPP) and late gadolinium enhancement (LGE) techniques. The purpose of this study was to compare the quantitative measurement of MVO by CMR in patients after acute myocardial infarction (AMI) using FPP and LGE techniques and to compare the power of these techniques in predicting left ventricular remodeling six months after AMI. 48 patients were studied, average age 57.0 years, with ST elevation AMI.Cardiac magnetic resonance imaging were performed at 7 days and 6 months on average after AMI. MVO was measured by FPP% and volume and LGE% and volume at the first CMR and measured ventricular remodeling by the variation > 12% of the left ventricular end systolic volume (LVESV) between the two exams. Statistical analysis showed a strong correlation between FPP and LGE (0.95 for volume and 0.96 for %). The FPP technique for both percentage and volume had the area under the ROC curve > 0.5, but with a small sample size. Logistic regression was performed to measure the effects of MVO measured by FPP% and volume and LGE% and volume on the LVESV difference in CMR. The odds ratio values found for MVO by LGE% and FPP% were statistically similar, as well as in univariate linear regression. Multivariate linear regressions showed that the measurement techniques of MVO per FPP% and LGE% are independent predictors of remodeling, unlike the left ventricular ejection fraction and the infarcted mass in the first CMR that had p> 0.05. It was concluded that the FPP and LGE techniques have strong correlation with each other; both are independent predictors of ventricular remodeling and that LGE% and FPP% are the best techniques in CMR to predict ventricular remodeling after AMI.