Improvement in Exercise Tolerance and Symptoms of Congestive Heart Failure During Treatment With Candesartan Cilexetil

Background—The renin-angiotensin system plays an important part in the pathogenesis of congestive heart failure (CHF). This study evaluated the effect of an angiotensin II type 1 receptor antagonist on exercise tolerance and symptoms of CHF. Methods and Results—In this multicenter, double-blind, parallel-group study, 844 patients with CHF were randomized to 12 weeks’ treatment with placebo (n5211) or candesartan cilexetil 4 mg (n5208), 8 mg (n5212), or 16 mg (n5213) after a 4-week placebo run-in period. Changes in exercise time, Dyspnea Fatigue Index score, NYHA functional class, and cardiothoracic ratio were determined. Candesartan cilexetil produced a dose-related improvement in exercise time. For the intention-to-treat population, the increase produced by candesartan cilexetil 16 mg was significantly greater than that produced by placebo (47.2 versus 30.8 seconds, P50.0463). All doses of candesartan cilexetil significantly improved the Dyspnea Fatigue Index score relative to placebo. NYHA class improved more frequently in the candesartan cilexetil groups; the differences relative to placebo were not significant. The decrease in cardiothoracic ratio with candesartan 4 to 16 mg was small but statistically significant compared with placebo (all P,0.05). In all candesartan cilexetil groups, plasma renin activity and angiotensin II levels increased from baseline and aldosterone levels decreased in the 8and 16-mg treatment groups. Candesartan cilexetil was well tolerated at all doses. Conclusions—In summary, treatment with candesartan cilexetil demonstrated significant improvements in exercise tolerance, cardiothoracic ratio, and symptoms and signs of CHF and was well tolerated. (Circulation. 1999;100:2224-2230.)