Nebivolol induces parallel improvement of left ventricular filling pressure and coronary flow reserve in uncomplicated arterial hypertension

PURPOSE: Our aim was to analyze the effects of 3-month antihypertensive therapy by nebivolol, a beta-blocking agent with nitric oxide-mediated vasodilatory properties, on coronary flow reserve (CFR) and left ventricular filling pressure (LVFP) in uncomplicated arterial hypertension. METHODS: Twenty newly diagnosed, never treated, uncomplicated hypertensive patients (14 male and six female patients, mean age = 49 years), I-II WHO grade, underwent single-blind nebivolol treatment. At baseline and at 3-month follow-up, patients underwent Doppler echocardiography including pulsed Tissue Doppler of septal mitral annulus: the ratio between transmitral E velocity and myocardial early diastolic velocity (E/Em ratio) was calculated as an index of LVFP degree. Transthoracic Doppler-derived CFR (high-dose dipyridamole coronary diastolic peak flow velocity to resting coronary peak flow velocity ratio) of distal left anterior descending artery was also determined. RESULTS: After 3-month nebivolol therapy, rate-pressure product decreased (P < 0.0001). No significant change of left ventricular mass index, relative wall thickness and midwall shortening was detected. Left ventricular end-diastolic diameter and stroke volume were both marginally increased. Nebivolol increased Em (P < 0.0001), reduced E/Em ratio (from 9.0 +/- 1.6 to 8.2 +/- 1.1, P < 0.0001) and enhanced CFR (from 2.07 +/- 0.2 to 2.20 +/- 0.2, P = 0.003), because of increased hyperemic coronary flow velocity (P < 0.001). CFR increase remained significant (P < 0.001) after normalizing resting and dipyridamole coronary velocities for the respective rate-pressure product. The increase of normalized CFR induced by nebivolol was related with E/Em ratio decrease (r = -0.65, P < 0.002). CONCLUSION: Nebivolol improves LVFP as well as CFR in uncomplicated hypertension. The association between changes of CFR and those of LVFP indicates a possible common denominator between improvement of coronary microvascular function and myocardial stimulation of nitric oxide release induced by the drug.