HEMODYNAMIC DIFFERENCES BETWEEN METOPROLOL AND CARVEDILOL IN HYPERTENSIVE PATIENTS

Resting hemodynamics were measured before, at 2 and 24 h after the fir st dose, and after 4 weeks of monotherapy with either metoprolol or ca rvedilol in a randomized single-blind study. We analyzed results from 24 hypertensive patients (30-68 years of age) with adequate blood-pres sure lowering on monotherapy. Acutely, both drugs lowered systolic blo od pressure and heart rate. Whereas metoprolol reduced cardiac output and increased both systemic and femoral artery resistance, carvedilol did not alter cardiac output but led to reductions in the systemic and regional resistances. After 4 weeks of therapy, cardiac output remain ed reduced and vascular resistances increased in the metoprolol group, whereas in carvedilol patients cardiac output continued to be unchang ed and the trend for vascular resistances to be decreased persisted. A cutely and chronically the differences in the hemodynamic effects of t he two medications were statistically significant. The study results i ndicate that carvedilol's vasodilatory action is not subject to tolera nce development. Chronic afterload reduction associated with the decre ase in systemic vascular resistance may lead to additional savings in myocardial oxygen consumption, a beneficial feature particularly in th ose patients with concomitant ischemic heart disease. It may also have a favorable influence on concentric cardiac hypertrophy and changes i n the walls of arteriolar resistance vessels. (C) 1998 American Journa l of Hypertension, Ltd.