Plasma levels of von Willebrand factor (vWF), a marker of endothelial dysfunction/damage, are elevated in high-risk hypertensive patients and in patients with severe aortic regurgitation (AR). Patients with mild-to-moderate AR, frequently detected in hypertensive elderly, have additional left ventricular morphological and functional dysfunctions. We hypothesized that hypertensive patients with mild-to-moderate AR may have enhanced endothelial and/or left ventricular dysfunctions that may lead to a deteriorated prognosis. We measured vWF, prothrombin F1+2 (F 1+2) as a marker of thrombin generation, brain natriuretic peptide (BNP) in 104 hypertensive patients with mild-to-moderate AR and 66 hypertensive patients without AR. The left ventricular diameter at systole (LVDs) and left ventricular posterior wall thickness (LVWT) were determined by echocardiography and indexed by body surface area (LVDs/BSA and LVWT/BSA). VWF (median, interquartile range (IQR) 154, 120-196%) and BNP (34.7 pg ml(-1), 15-65%) levels were greater in patients with AR than in those without AR (135, 98-175% and 20, 10.3-49 pg ml(-1)). All patients were prospectively followed up for cardiac events during the period of median 43 months (IQR 31-81). Patients with AR had an increased risk of cardiac events (regression ratio (RR) 1.87, 95% confidence interval 1.28-2.87) when compared to those without AR. A multivariate Cox hazard analysis indicated that log vWF (RR 4.93) and log BNP (RR 1.9) were independent predictors in patients with AR. VWF was an independent predictor of clinical outcome in hypertensive patients with mild-to-moderate AR.