Abstract--Prevalence, determinants, and prognostic value of asymptomatic left ventricular systolic dysfunction (LVSD) in uncomplicated subjects with essential hypertension are still incompletely known. We studied 2384 initially untreated subjects with hypertension, no previous cardiovascular disease, and no symptoms or physical signs of congestive heart failure (CHF). These subjects were studied at entry and followed for up to 17 years (mean 6.0). Asymptomatic LVSD (ALVSD), defined by an echocardiographic ejection fraction <50%, was found in 3.6% of subjects. Cigarette smoking (P=0.013), increased left ventricular (LV) mass (P=0.001), and higher 24-hour heart rate (P=0.014) were independent correlates of ALVSD. During follow-up, a first cardiovascular event occurred in 227 subjects, and 24 of these events were hospitalizations for symptomatic CHF. Incidence of CHF per 100 persons per year was 0.12 in patients without and 1.48 in patients with ALVSD (log-rank test P=0.0001). In a Cox model, after adjustment for age (P=0.0001), LV mass (P=0.0001), and cigarette smoking (P=0.039), LVSD conferred a markedly increased risk for CHF (odds ratio, 9.99; 95% confidence interval, 3.67 to 27.2). Incidence of coronary (0.84 versus 0.62x100 person years) and cerebrovascular (0.80 versus 0.62x100 person years) events did not differ (all P=NS) between subjects with and without ALVSD. ALVSD is a potent and early marker of evolution toward severe CHF requiring hospitalization in subjects with essential hypertension.