Abstract 11521: Prognostic Value of Left Atrial Function in Normal Exercise Stress Echocardiography

Abstract

Background: The association between poor left atrial (LA) function and adverse outcomes in subjects following an acute myocardial infarction is recognized. On the other hand, prognostic value of LA function in low risk subjects is not well characterized. The purpose of this study was to assess the prognostic value of LA function in subjects who have exercise stress echocardiography negative for ischemia. Methods: Subjects who underwent exercise stress echocardiography for exclusion of coronary artery disease (CAD) between January to April 2010 were included. Subjects were excluded if they were in atrial fibrillation/flutter at the time of exercise, left ventricular ejection fraction (LVEF) < 45%, moderate or severe valvular disease, echocardiographic evidence of exercise-induced myocardial ischemia, or had known CAD. Maximum metabolic equivalents (METs), LA total strain (analyzed offline with Siemens Syngo VVI), LV E/e’, LA volume index (LAVI) were measured for all subjects. Diagnosis of major adverse cardiac events (MACE: myocardial infarction, coronary revascularization, cardiovascular mortality) and coronary artery disease (CAD: angina, unstable angina) were recorded. Results: Of 672 subjects identified, 486 subjects remained after exclusion. The mean follow up time was 51.6 ± 1.2 months, and the mean LVEF was 56 ± 5%. Following the index stress test, 25 (5%) subjects had MACE and 35 (7%) subjects had CAD. With MACE, maximum METs was a strong prognostic factor, with worse outcome when METs < 9 (median = 9). None of the echocardiographic parameters reached statistical significance. For CAD, none of the variables reached statistical significance including METs. Conclusions: In subjects who have negative exercise stress test for ischemia, reduced METs was strongly associated with adverse outcomes. In this low risk population, none of the tested LA echocardiographic parameters appeared to be associated with adverse outcomes.