Aim: To compare the effects on maximal exercise tolerance of 12 weeks of four dosages of telmisartan (10/20/40/80 mg once daily), an AT(1) specific angiotensin II receptor antagonist, or continuation on the angiotensin converting enzyme inhibitor enalapril, in patients with stable, mild-to-moderate congestive heart failure (NYHA Class II and III and left ventricular ejection fraction < or =40%).
Design: Multicenter, double-blind, parallel-group trial in 378 patients, randomized to once-daily treatment with telmisartan 10, 20, 40 mg, 80 mg, or continuation of enalapril 10 mg twice daily for 12 weeks.
Methods: Primary efficacy parameter: change from baseline to final visit in bicycle exercise duration. Secondary efficacy parameters included left ventricular ejection fraction, quality-of-life parameters, arterial blood pressures, neurohormonal changes and NYHA classification.
Patients: The mean age of the patients was 64+/-9 years, 89% male, history of myocardial infarction in 68%, NYHA-II: 63%, NYHA-III: 37%, ejection fraction 26.4(7)%, and a reproducible impaired exercise capacity. All patients were on diuretics and enalapril 10 mg twice daily, and 39% were taking digitalis at study entry.
Results: No clinically relevant or statistically significant (P<0.05) differences were observed in the primary efficacy parameter: mean changes (s) in exercise tolerance were +8.6, +8.2, +2.2, and +7.1 for the telmisartan 10-, 20-, 40-, and 80-mg groups, respectively, and +1.4 for enalapril. There was a small but significant increase in blood pressure in all but the 80 mg telmisartan groups, compared to enalapril. Telmisartan and enalapril had comparable adverse event profiles. Cough occurred in 5.6% of the enalapril patients and in 3% of the telmisartan patients (NS).
Conclusions: (1) In patients with stable, mild-to-moderate congestive heart failure, enalapril could be replaced by telmisartan for a period of 12 weeks without deterioration in exercise capacity or clinical status. (2) No differences were observed in exercise capacity between the four dosages of telmisartan.