Abstract 11880: Effects of Left Atrial Function on Pulmonary Arterial Pressure in Acute Myocardial Infarction, Hypertrophic and Dilated Cardiomyopathy

Abstract

Introduction: We evaluated differential contribution of the left atrial (LA) function by cardiovascular magnetic resonance (CMR) and left ventricular (LV) fibrosis to pulmonary arterial systolic pressure in hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM) and reperfused acute myocardial infarction (AMI). Hypothesis: The differential role of the LA function and LV fibrosis indices for pulmonary pressure elevation would be different in various myocardial diseases and there would be a predictive value in addition to the conventional echocardiographic parameters. Methods: Data of 370 patients with HCM (n=133), DCM (n=114) and reperfused AMI (n=123) who underwent both echocardiography and CMR were comprehensively reviewed. Phasic LA volumes, LA-global longitudinal strain (GLS), LA stiffness index, defined as E/e’/LA-GLS and extracellular volume fraction (ECV) of LV were measured using CMR. Results: E/e’ was correlated with PASP in all groups; however, the predicted value was significantly attenuated after adjusting for LA volume and LA strain in HCM and DCM, but remained significant in AMI. The LA stiffness index was related to PASP in HCM (p=0.01) and DCM (p=0.03) independent of LA volume index and E/e', but not in AMI. In DCM, ECV was significantly related to PASP (p<0.001) independent of LA volume index and E/e’. Conclusions: The LA function in HCM and DCM and LV fibrosis in DCM correlated with PASP independent of E/e’ and LA size, contrary to that in AMI. These results suggest the presence of left atrial dysfunction in non-ischemic cardiomyopathies and usefulness of ECV measurement in DCM for the comprehensive evaluation of LV diastolic function.