Ivabradine in clinical practice: benefits of If inhibition

Relieving the symptoms of angina and improving the quality of life and functional status are important objectives in the management of patients with chronic stable angina. A high heart rate induces or exacerbates myocardial ischaemia and angina, because it both increases oxygen demand and decreases myocardial perfusion, the latter by shortening the duration of diastole. Moreover, there is a large body of evidence about the relationship between high resting heart rate and mortality, documented in different population types. β-Blockers are effective in reducing angina largely by decreasing heart rate. Physician use and patient compliance may be limited by the side effects of β-blockers, which include fatigue, depression, and sexual dysfunction. Heart rate reduction can also be obtained by some calcium antagonists and by the new agent ivabradine. Ivabradine (Procoralan) is a selective and specific If inhibitor, which acts on one of the most important ionic currents for the regulation of the pacemaker activity of sinoatrial node cells. Ivabradine has demonstrated dose-dependent anti-ischaemic and anti-anginal effects at dosages of 5, 7.5, and 10 mg bid in an extensive programme of more than 5000 patients. The non-inferiority of ivabradine was shown vs. the β-blocker atenolol and the calcium-channel blocker amlodipine. Unlike β-blockers, ivabradine is devoid of intrinsic negative inotropic effects and does not affect coronary vasomotion. A whole range of patients with angina may benefit from exclusive heart rate reduction with ivabradine, including those with contraindications or intolerance to the use of β-blockers and patients who are insufficiently controlled by β-blockers or calcium-channel blockers.