Long-Term Vasodilator Therapy with Trimazosin in Chronic Cardiac Failure

Abstract

Patients with cardiac failure have a generalized sympathetic vasoconstriction that may impair cardiac function and exercise tolerance. The ability of long-term alpha-receptor blockade and vasodilation with trimazosin (TMZ) to improve exercise capacity was studied in patients with chronic, stable heart failure of varying severity (functional exercise classes B to D). Exercise performance was monitored by respiratory gas exchange and air flow before and after patients were randomized to placebo (13 patients) or TMZ (10 patients) for six weeks. Twelve of 13 patients given placebo and subsequently TMZ and 10 patients given TMZ were then followed on treatment for up to 52 weeks. Significant (P<0.05) and sustained increases in exercise capacity, oxygen uptake, and oxygen pulse were observed with TMZ treatment in each Class B or C patient and in six of nine Class D patients, and were not observed during treatment with placebo. (N Engl J Med. 1980; 303: 242–50.)