RESUMO
INTRODUCTION: This study assessed the effects of Nebivolol on left ventricular (LV) function and exercise capacity in patients with non-ischaemic dilated cardiomyopathy (NIDC). METHODS: After enrolment in this double-blind trial, 60 patients, aged 55 +/- 9.5 years, with angiographically proven NIDC, LV ejection fraction (EF) < 45%, NYHA class II-III, were randomised to either Nebivolol (target dose 5 mg) or placebo and were evaluated using echocardiography and exercise tests over 3 months. RESULTS: There were no baseline differences between the 2 groups regarding NYHA class, heart rate (HR), blood pressure (BP), LVEF or other echocardiographic variables. During follow-up, 4 patients in the Nebivolol and 5 in the placebo group discontinued treatment. After 3-months' treatment a significant decrease in NYHA class (p = 0.001), resting HR (p = 0.03), systolic and diastolic BP (both p < 0.001), left atrial diameter (p = 0.01) and LV end-systolic volume (p = 0.046), and an increase in LVEF (p = 0.01) were observed in the Nebivolol group compared to placebo. The atrial contribution to total LV filling (p = 0.007) and the pulmonary venous (PV) systolic wave velocity (p = 0.007) increased, whereas the atrial PV component decreased (p < 0.001) in the Nebivolol patients compared to placebo. Exercise duration decreased at 3 months (p = 0.01) compared to placebo, probably as a result of reduced maximal exercise HR (p < 0.001). CONCLUSIONS: Nebivolol is a safe and well-tolerated drug that improves NYHA class, systolic and diastolic LV function in NIDC patients, although it is associated with a lower maximal exercise duration at 3 months.