[Reliability of cardiac magnetic resonance imaging indicators of myocardial viability for predicting the recovery of systolic function after a first acute myocardial infarction with a patent culprit artery]. / Fiabilidad de los índices de viabilidad miocárdica por resonancia magnética para predecir la mejoría de la función sistólica en pacientes con un primer infarto reciente y arteria abierta.

ABSTRACT

INTRODUCTION AND OBJECTIVE: To assess the reliability of early analysis of the most frequently used cardiac magnetic resonance (CMR)-derived indexes for predicting systolic function recovery and ventricular remodeling in patients after a first acute myocardial infarction with a patent culprit artery. PATIENTS AND METHOD: 17 patients were studied with an initial CMR protocol that included regional assessment of wall thickness and wall thickening, low-dose dobutamine response, first-pass gadolinium myocardial perfusion imaging and delayed enhancement. These results were compared with those obtained for segmental and global function in a second CMR study 6 months later. RESULTS: Of the 272 myocardial segments evaluated in the initial study, 73 showed severe systolic dysfunction. The findings were used to calculate sensitivity and specificity of each of the indexes mentioned above for predicting myocardial viability. The sensitivities and specificities for each index were wall thickness > or =5.5 mm, 100% and 12%; low-dose dobutamine response, 41% and 93%; normal myocardial perfusion, 78% and 68%; delayed enhancement, 81% and 95%. Multivariate analysis showed that delayed enhancement was the only independent predictor of contractility (r=-0.83, P=.0001), ventricular volumes (end-diastolic r=0.61, P=.009, end-systolic r=0.67, P=.003) and ejection fraction (r=-0.73, P=.001) at 6 months. CONCLUSIONS: Delayed enhancement seen in CMR is a reliable, quantifiable index for predicting recovery of systolic function and ventricular remodeling in patients after a first infarction with a patent culprit artery.