[Effects of chronic antihypertensive treatment with ketanserin versus metoprolol on blood pressure and compliance of great arteries in man: a double-blind crossover study].

The antihypertensive efficacy of a receptor antagonist of serotonin was compared with a widely known antihypertensive drug, metoprolol, and their effects on cardiac and forearm hemodynamics were studied using echocardiography and flowmetry with pulsed bidimensional Doppler. Twenty patients with hypertension completed a randomized double-blind crossover study, using ketanserin and metoprolol. Two periods of 5 weeks with ketanserin or metoprolol were preceded by a placebo period the total duration of the study was 15 weeks. Although comparable efficacy in reducing systolic and diastolic pressure, (by about 10% of base-values), was observed, the two drugs showed quite different effects on forearm hemodynamics. Ketanserin increased blood flow to the forearm and induced a significant decrease in the vascular resistances of the forearm (from 141 +/- 16 to 75 +/- 11 mmHg/mL/s; p less than 0.01). Moreover, this treatment was able to improve the compliance of the brachial artery (from 1.89 +/- 0.3 to 3.2 +/- 0.3 cm4/dyn 10(-10); p less than 0.01). On the contrary, metoprolol did not modify forearm hemodynamics. Neither drug modified cardiac performance, as assessed by the circumferential shortening of the fibers of the left ventricle. Cardiac output was increased by ketanserin (from 5.9 +/- 0.3 to 6.6 +/- 0.5 L/min; p less than 0.05) and reduced during treatment with metoprolol (from 5.9 +/- 0.4 to 4.9 +/- 0.3 L/min; p less than 0.01). Thus the two drugs reduced arterial pressure by different hemodynamic mechanisms and the effects of ketanserin on systemic and peripheral circulation seem more favourable.