Bisoprolol improves survival in rats with heart failure

The cardioprotective effects of bisoprolol were studied in a rat model of s evere heart failure induced by autoimmune myocarditis. Twenty-eight days af ter immunization, Lewis rats were divided into four groups: 0.1 mg/kg/day b isoprolol (Group 0.1), 1.0 mg/kg/day bisoprolol (Group 1) and 10 mg/kg/day bisoprolol (Group 10), and vehicle (0.5% methylcellulose; Group V) (all gro ups, n = 13). After oral administration for 1 month, heart weight, mean blo od pressure, heart rate, central venous pressure, peak left ventricular pre ssure, left ventricular end-diastolic pressure, +/- dP/dt, and area of fibr osis were measured. Although bisoprolol reduced heart rate (399 +/- 11/min in Group V, 382 +/- 10/min in Group 0.1, 348 +/- 8/min in Group 1 and 302 /- 9/min in Group 10) and increased survival (62% in Group V 69% in Group 0 .1, and 100% in Group 1 and Group 10) in a dose-dependent manner, this drug did not change heart weight, the area of myocardial fibrosis or hemodynami c parameters. These observations suggested that bisoprolol may improve surv ival independently of its effect on left ventricular function by reducing s udden death in patients with severe heart failure.