Abstract 9320: Biological Sex as a Modifier of the Natural History of Dilated Cardiomyopathy

Abstract

Introduction: Dilated cardiomyopathy (DCM) has a ~20% 5-year mortality rate. Understanding the impact of biological sex offers scope to improve outcomes. Objective: Investigate potential sex specific differences in the outcome of DCM. Methods: Prospective longitudinal observational cohort study of 604 patients (n=206 women, 398 men) with DCM confirmed by cardiac MRI. The median follow up for cardiovascular death, major heart failure and arrhythmic events was 3.9 years. Results: At baseline women had higher left ventricular ejection fraction (LVEF), smaller left ventricular volumes, less myocardial fibrosis and lower serum troponin concentrations (all p<0.05, Table 1), with no difference in age at study enrolment or medication. Despite this favourable profile, within 2 years women had more primary outcome events than men (Figure) with Kaplan Meier estimates of 10.7% vs 5.1%; adjusted* hazard ratio 3.47, 95% CI 1.81 to 6.65, [*age, LVEF, troponin, LMNA , left atrial volume and myocardial fibrosis]. Between 2-5 years, men and women had similar outcomes (adjusted* HR 0.55; 0.17,1.78). An LVEF <35% in men (HR 3.21, 1.67 to 6.18, C-statistic 0.647) but <40% in women (HR 2.37, 1.05 to 5.36, C statistic 0.602) had the greatest discrimination for predicting outcome. Conclusions: Female sex is an adverse modifier of the early natural history of DCM. There is evidence for sex specific risk stratification thresholds. Sex should be considered a determining variable in DCM care.