Abstract 12273: Correlation Between Aortic Strain and Native T1 Value in Hypertrophic Cardiomyopathy

Introduction: Aortic stiffness is related to impairment of left ventricular (LV) function and LV remodeling. Myocardial ischemia and fibrosis in hypertrophic cardiomyopathy (HCM) cause ventricular arrhythmia and sudden cardiac death. Magnetic resonance imaging (MRI) can evaluate aortic stiffness and LV function noninvasively. Aortic strain shows the possibility for the assessment of the aortic status and T1 mapping allows the assessment of diffuse myocardial fibrosis. Hypothesis: We assessed the hypothesis that aortic strain is correlated with native T1 values in HCM patients. Methods: Thirty-six HCM patients (mean age : 64±2 years) and forty control subjects (mean age : 58±3 years) with no history of coronary artery disease were examined using a 3T MRI. Cross-sectional aortic areas of the descending aorta were measured and aortic strain was calculated as follows: aortic strain (%) = (maximum aorta area - minimum aorta area)/minimum aorta area х 100. Native T1 values were measured as an averaged T1 values in the septum of 3 short-axis slices of base-to-apex left ventricle myocardium. LV ejection fraction (LVEF), left atrium (LA) dimension and E/e’ were measured by echocardiography. Results: LVEF showed no significant differences between HCM patients and control subjects (66.2±1.1% vs. 64.5±1.0%, p=0.2488). LA dimension and E/e’ in HCM patients were significantly higher than control subjects (LA dimension: 38.3±1.1mm vs 34.9±0.85mm, p=0.0155, E/e’: 13.4±0.95 vs 9.2±0.42, p<0.0001). Native T1 values and aortic strain of the descending aorta in HCM patients were significantly lower than those in control subjects (native T1 values: 1254±8ms vs 1208±8ms, p<0.0001, aortic strain: 7.95±0.66% vs 12.92±1.27%, p=0.0012). Multiple linear regression analysis revealed that aortic strain was correlated with age (β=-0.370, p=0.0014) and native T1 values (β=-0.244, p=0.0448). Conclusions: In HCM patients, aortic strain of the descending aorta was significantly decreased compared to control subjects and correlated with native T1 values. Aortic strain may be a promising factor for myocardial fibrosis in HCM patients.