Usefulness of Left Ventricular Dyssynchrony After Acute Myocardial Infarction, Assessed by a Tagging Magnetic Resonance Image Derived Metric, as a Determinant of Ventricular Remodeling

Abstract

Development of left ventricular (LV) remodeling after acute myocardial infarction (AMI) is a serious medical complication. We investigated the correlation of LV dyssynchrony after AMI with LV remodeling using magnetic resonance-myocardial tagging (MR-MT) derived dyssynchrony index (circumferential uniformity ratio estimate [CURE]). Forty-three patients diagnosed with ST-elevation AMI were analyzed. After treatment with primary percutaneous intervention, cardiac magnetic resonance imaging was performed to obtain a cine image, a delayed enhancement image, and an MR-MT image. CURE as a dyssynchrony index was calculated from the MR-MT image using HARP software (CURE 0 to 1 = dyssynchrony to synchrony). After 6 months, follow-up cardiac magnetic resonance imaging was performed to assess degree of LV remodeling. Sixteen patients (37%) had an increased LV end-systolic volume (ESV) >15% compared with baseline. The baseline LV dyssynchrony index, CURE, was significantly associated with ESV at 6 months (r = -0.49, p <0.001) and weakly correlated with change in ESV (percentage) compared with baseline values (r = -0.26, p = 0.08). Multivariate analysis showed that CURE was associated only with change in ESV (beta -0.39, p = 0.03). Subgroup analysis for patients with nonviable myocardium (infarct thickness >75%, n = 31) showed that this correlation was stronger (beta -0.52, p = 0.006), suggesting that CURE could predict progression of LV remodeling in patients with AMI and nonviable myocardium. LV dyssynchrony immediately after AMI is an important determinant of LV remodeling. In conclusion, the MR-MT dyssynchrony index, CURE, might be useful for prediction of LV remodeling in patients with AMI.