The role of ivabradine in the incidence of perioperative coronary complications in patients undergoing vascular surgery

Abstract

The management of perioperative myocardial damage is focused on two issues: coronary plaque stabilization to reduce acute coronary syndromes and the subsequent supply ischemia (type 1MI) that occurs when a coronary plaque ruptures; and limiting surgical stress, which is the cause of the sustained myocardial oxygen supply–demand imbalance (type 2 MI) [1]. Prophylactic pre-operative coronary revascularization in patients scheduled for non-cardiac surgery has failed to show any benefit [2,3]. In contrast, the most recent guidelines recommended the use of β-blockers in patients having high-risk surgery [4]. On the other hand, results of some other clinical trials do not support the use of perioperative β-blockers for the high risk of bradycardia and hypotension, stroke and death [5,6]. Ivabradine, specific inhibitor of the If current in sinoatrial node myocytes, reduces heart rate independently of sympathetic activation, and has demonstrated a reduction in the risk of coronary events in patients with elevated heart rate (≥70 bpm) or angina at baseline [7,8]. The objective of the current study was to determine if ivabradine would be equally effective to β-blockers in reducing cardiovascular risk in patients undergoing major vascular surgery in whom beta-blockers were contraindicate or unsafe. 244 consecutive patients scheduled for open or endovascular aortic aneurysm repair. The internal review board approved the study project and all patients gave their informed consent. Patients with ≤2 cardiac risk factors on the Lee index score and a heart rate b 70 bpm were directly referred for surgery with optimal medical therapy, which must have been initiated at least 30 days before. Patients with ≥3 clinical risk factors on the Lee index score were referred for non-invasive cardiac stress testing echocardiography before surgery as recommended in the ESC guidelines [4]. All patients in the study received optimal medical therapy according to current guidelines [9] for at least 30 days before the planned surgical procedure and all patients with a heart rate ≥ 70 bpmwere assigned to a heart rate control strategy with βblockers or ivabradine. In the β-blocker group, bisoprolol 2.5 mgwas started once a day and titrated to achieve thepreferred restingheart rate range (60–65 bpm). In eligible patients, ivabradine was administered at a dose of 5–7.5 mg twice a day,with the sameheart rate target. The samedose ofβ-blockers or ivabradine was continued post-operative. At the discharge we confirm the treatment for six months and then to consult their cardiologist. The primary endpoint was a composite of all-cause mortality and nonfatal MI that occurred between screening and 30 days after the surgical procedure. Postoperative events were cardiac and overall complications. Troponin T levels were routinely recorded on postoperative days 1 and3orwhenever therewere symptomsor evidenceof new myocardial ischemia.