Ivabradine Versus Beta-Blockers in Patients with Conduction Abnormalities or Left Ventricular Dysfunction Undergoing Cardiac Surgery

INTRODUCTION In patients with conduction abnormalities or left ventricle (LV) dysfunction the use of β-blockers for post cardiac surgery rhythm control is difficult and controversial, with a paucity of information about other drugs such ivabradine used postoperatively. The objective of this study was to compare the efficacy and safety of ivabradine versus metoprolol used perioperatively in cardiac surgery patients with conduction abnormalities or LV systolic dysfunction. METHODS This was an open-label, randomized clinical trial enrolling 527 patients with conduction abnormalities or LV systolic dysfunction undergoing coronary artery bypass grafting or valvular replacement, randomized to take ivabradine or metoprolol, or metoprolol plus ivabradine. The primary endpoints were the composites of 30-day mortality, in-hospital atrial fibrillation (AF), in-hospital three-degree atrioventricular block and need for pacing, in-hospital worsening heart failure (HF; safety endpoints), duration of hospital stay and immobilization and the above endpoint plus in-hospital bradycardia, gastrointestinal symptoms, sleep disturbances, cold extremities (efficacy plus safety endpoint). RESULTS Heart rate reduction and prevention of postoperative AF or tachyarrhythmia with combined therapy was more effective than with metoprolol or ivabradine alone during the immediate postoperative management of cardiac surgery patients. In the Ivabradine group, the frequency of early postoperative pacing and HF worsening was smaller than in the Metoprolol group and in combined therapy group. The frequency of primary combined endpoint was lower in the combined Ivabradine + Metoprolol group compared with the monotherapy groups. CONCLUSION Considering efficacy and safety, the cardiac rhythm reduction after open heart surgery in patients with conduction abnormalities or LV dysfunction with ivabradine plus metoprolol emerged as the best treatment in this trial.