Efficacy of ivabradine and bisoprolol in patients with stable angina: results of comparative randomized open-label study

Introduction: It has been demonstrated that in patients with stable angina (SA) drugs and interventional therapy can be equally efficient. Aim of the study: To examine in patients with SA the influence of ivabradine as compared with bisoprolol on clinical and hemodynamic indices, exercise tolerance, flow mediated vasodilatation (FMD), lipid profile, quality of life (QoL) and erectile function. Material and methods: 60 male patients with SA were included into the prospective, randomized crossover open-label study. Half of the patients received ivabradine over the period of 14 days followed by change onto bisoprolol for 3 months, whereas the other half received the drugs in inverted sequence. Treadmill exercise tolerance test (ETT) and flow-mediated dilatation (FMD) test were performed at baseline and 14 days after treatment with each of the preparations. The QoL was evaluated after 3 months with the use of the Seattle Angina Questionnaire (SAQ) and erectile function was assessed with the IIEF-5 Questionnaire. The concentrations of plasma lipids, fasting glucose and C-reactive protein were also measured. Results: Mean exercise duration on ETT increased by 89.7 s on bisoprolol (P<0.005) and by 96.4 s while receiving ivabradine (P<0.005). The time to 1 mm ST depression increased by 94.2 s on bisoprolol use (P<0.005) and by 101.8 s in ivabradine (P<0.005). The treatment with ivabradine was accompanied by a more increased chronotropic reserve on treadmill-test (Р<0.05). Ivabradine improved FMD (Р<0.05) and shear stress sensitivity coefficient of brachial artery (P<0.05). Ivabradine had no effect on the lipid levels or fasting glucose. Both drugs significantly improved QoL, but the treatment with ivabradine significantly improved the erectile function (Р<0.005), as compared with bisoprolol. Conclusions: Ivabradine showed similar antianginal and antiischemic effect as bisoprolol and may be recommended for the SA patients with contraindication or intolerability of β-blockers. Our findings suggest that ivabradine may better preserve endothelial function and could be the preferred agent for patients with erectile dysfunction.