Absolute values of late enhancement volume is superior to percentage of late enhancement volume per total LV myocardium volume to predict MACE in hypertrophic cardiomyopathy: a CMR Study

Abstract

Purpose: To determine a useful predictor of major adverse cardiac events (MACE) in patients with hypertrophic cardiomyopathy (HCM), we compared focal late enhancement (LE) volume (LEV) in the left ventricular myocardium (LVM) to the percentage of LEV per total LVM volume (TLVMV) (%LEV/TLVMV) by cardiac magnetic resonance (CMR), and followed subjects for a median of 16 months. Methods: Fifty-five consecutive HCM subjects (33 males, mean age 62.5±13.6 years) undergoing CMR (1.5T Intra achieva, Philips) were recruited. CMR was acquired at 15 min after injection of Gadopentetate dimeglumine for detecting LEV in LVM quantitatively. Areas with signal-intensity ≥ mean+2SD of signal-intensity of remote normal LVM were regarded as LE. LEV was measured by the threshold method (Ziostation 2, Zio). Result: LE in LVM was detected in 46 subjects, and LEV and %LEV/TLVMV were 35.4±27.1cm3 and 25.0±19.2%, respectively. Ten subjects (18%) had MACE. According to Receiver Operating Characteristic (ROC) curves, at a cutoff of 45.6cm3 (LEV) and 23.8% (%LEV/TLVMV), the sensitivity and specificity of LEV for MACE detection were 80% and 75%, respectively (Area under curve (AUC) 0.766) and those of %LEV/TLVMV were 100% and 59% (AUC 0.811), respectively. HCM subjects were divided into groups on the basis of 1) LEV ≥ and <45.6cm3 and (2) %LEV/TLVMV ≥ and <23.8%. Significant differences between Group 1 and Group 2 subjects were observed on Kaplan Meier analysis and log rank test (both P<0.01). On Cox proportional hazard models, the hazard ratios for the occurrence of MACE were 8.08 (LEV, P=0.008) and 60.8 (%LEV/TLVMV, P=0.118), and only the former was significant. ![Figure][1] ROC curves Conclusion: Both LEV and %LEV/TLVMV by CMR may be useful to predict the risk of MACE in HCM subjects, and LEV is superior to %LEV/TLVMV. [1]: pending:yes