Abstract 3363: Anti-Ischemic and Antianginal Efficacy of Ivabradine, a Selective and Specific If Current Inhibitor, in Elderly Patients with Stable Angina
Background: Ivabradine, a novel heart rate-reducing agent acting on the sinus node If current, was found to be as effective as atenolol in a 4-month, randomized, double-blind noninferiority trial conducted in 939 patients, the INternatIonal TrIal of the AnTianginal effects of IVabradinE compared to atenolol (INITIATIVE). Since a sharp increase with age in the prevalence of stable angina is currently being observed (3/4 of patients older than 65), it was of particular interest to confirm the efficacy and tolerability of ivabradine in this population.
Method: The antianginal and anti-ischemic efficacy of ivabradine was evaluated in a subpopulation from the INITIATIVE trial of 232 patients aged 65 or more, with documented coronary artery disease. Patients were randomized to ivabradine 7.5 mg bid. (n=113) or atenolol 100 mg od (n=119). The evaluation criteria used were changes in total exercise duration (TED/ primary end point) and time to 1-mm ST-segment depression (TST) at trough of drug activity at 4 months. General tolerability was also assessed.
Results: In elderly patients, TED increased by 88.7±119 s (15.6% from baseline) with ivabradine 7.5 mg bid and by 65.6±136.6 s (11.8% from baseline) with atenolol 100 mg od. TST increased by 101.9±145.9 s (21% from baseline) with ivabradine and by 81.7±150.5 s (17.3% from baseline) with atenolol. In comparison with the overall population, the improvement in TED and TST with ivabradine in the elderly population was maintained, even showing a trend toward superior effectiveness, which was not observed with atenolol.
Conclusion: This analysis demonstrates that the good clinical efficacy and tolerability of ivabradine in stable angina, previously demonstrated versus atenolol in 939 patients, is maintained in elderly patients. Since the prevalence of coronary artery disease is continuously increasing with age and is becoming a major public health concern in the elderly, these results may have important clinical implications.