ABSTRACT
PURPOSE: The antianginal and anti-ischemic efficacy of the selective I (f) inhibitor ivabradine is established in patients with stable angina in monotherapy and in combination with other antianginals, including beta-blocker. This pilot study compared the antianginal and anti-ischemic efficacy and hemodynamic profile of ivabradine plus 5 mg bisoprolol versus those of 10 mg bisoprolol in patients with stable angina. PATIENTS AND METHODS: Twenty-nine patients with stable angina and moderate left ventricular systolic dysfunction already on bisoprolol 5 mg od were randomized into 2 groups. Group 1 (n = 17) received ivabradine (5-7.5 mg bid) in addition to bisoprolol 5 mg od, while in group 2 (n = 12) bisoprolol was uptitrated first to 7.5 mg and then 10 mg od. Patients underwent a treadmill test, 6-minute walking test, and echocardiography at baseline and after 2 months. RESULTS: Mean resting heart rate decreased in both groups, from 76.6 ± 4.6 bpm to 59.3 ± 2.5 bpm (P < 0.001) in group 1 and from 75.9 ± 3.0 bpm to 60.5 ± 2.3 bpm (P = 0.002) in group 2. The effect on resting heart rate did not differ significantly between the two groups. However, more patients became asymptomatic in group 1 than in group 2. Addition of ivabradine also improved exercise capacity, as shown by the results of the 6-minute walking and exercise tolerance tests, whereas in group 2 neither parameter was significantly affected. Chronotropic reserve significantly improved with ivabradine, but not with bisoprolol 10 mg. CONCLUSIONS: These results suggest that combining ivabradine with low dose bisoprolol in stable angina patients produces additional antianginal and anti-ischemic benefits and improves chronotropic reserve.
