Different effects of atenolol and nebivolol on coronary flow reserve

Atenolol and nebivolol are commonly used antihypertensive agents. Nebivolol increases both stimulated and basal release of endothelial nitric oxide, thereby improving flow-mediated dilatation of the brachial artery in patients with essential hypertension.1 However, it is believed that atenolol has no effect on arterial vasoreactivity.1 Pharmacological stress transthoracic second harmonic Doppler echocardiography (TTDE) is a useful tool in evaluating coronary flow reserve (CFR). Several studies have evaluated its feasibility.2 We hypothesised that in patients with essential hypertension, nebivolol can reverse coronary microvascular dysfunction and improve CFR. After one month of lifestyle changes, 63 consecutive patients with hypertension had 24 h ambulatory blood pressure monitoring. Hypertension was diagnosed in 30 of these who had average daytime blood pressure > 135/85 mm Hg and average night-time blood pressure > 125/75 mm Hg. These 30 patients constituted the study population. For the control group, 30 healthy volunteers were enrolled. Patients with known cardiovascular risk factors, those who were taking any vasoactive or hypertension drug, and those with ECG changes specific for myocardial ischaemia were excluded from the study. Written informed consent was obtained from each participant, and the institutional ethics committee approved the …