Abstract 10275: Aortic Dilatation is Common in Hypertrophic Cardiomyopathy

Abstract

Introduction: Aortic dilatation has been associated with various cardiac conditions, although its prevalence and clinical correlates in hypertrophic cardiomyopathy (HCM) remains unclear. Hypothesis: We hypothesized that tubular ascending aorta dilatation would be common in a large referral population of patients with HCM. Furthermore, we hypothesized that aortic size would correlate with age and presence of left ventricular outflow tract obstruction. Methods: 1704 patients with HCM underwent echocardiographic measurement of the tubular ascending aorta during index evaluation at a tertiary HCM referral center. End-diastolic ascending aorta dimension was indexed to body surface area, with dilatation defined as two standard deviations above normal (>19 mm/m2). Aortic size and presence of aortic enlargement were correlated with clinical and echocardiographic parameters. Results: Aortic dilatation was present in 304 patients with HCM (18%). Indexed ascending thoracic aorta dimension was 16.5 (IQR 17.8-18.2) mm/m2 (Figure 1). Indexed dimension increased linearly with age (R=0.53, p<0.0001). Women and patients with a history of systemic hypertension were more likely to have aortic enlargement (29.8% vs 9.9% and 24.1% vs 10.6%, p<0.0001 for both). There was a correlation between resting left ventricular outflow tract gradient and indexed aortic dimension (R=0.12, p<0.0001) and patients with either resting (≥30 mmHg) or provocable obstruction (≥50 mmHg) were more likely to have aortic enlargement (19.6% vs 14.3%, p=0.006). Conclusions: In this large cohort of patients with HCM, aortic dilatation was common. Key correlates of aortic enlargement included age, female sex, history of hypertension and left ventricular outflow tract obstruction. Given an increased prevalence of aortic dilatation in HCM, further study is needed on the clinical impact of aortic dilatation.