Effect of ivabradine on left ventricular remodelling after reperfused myocardial infarction: A pilot study

Abstract

Background: Heart rate is a major determinant of myocardial oxygen demand; in ST-segment elevation myocardial infarction (STEMI), patients treated with primary percutaneous intervention (PPCI), heart rate at discharge correlates with mortality. Ivabradine is a pure heart rate-reducing agent that has no effect on blood pressure and contractility, and can reverse left ventricular (LV) remodelling in patients with heart failure.

Aims: To evaluate whether ivabradine, when added to current guideline-based therapy, improves LV remodelling in STEMI patients treated with PPCI.

Methods: This paired-cohort study included 124 patients between June 2011 and July 2012. Ivabradine (5mg twice daily) was given promptly after PPCI, along with beta-blockers, to obtain a heart rate<60 beats per minute (ivabradine group). This group was matched with STEMI patients treated in line with current guidelines, including beta-blockers (bisoprolol), according to age, sex, infarct-related coronary artery, ischaemia time and infarct size determined by initial cardiac magnetic resonance imaging (CMR) (control group). Statistical analyses were performed according to an intention-to-continue treatment principle. CMR data at 3 months were available for 122 patients.

Results: Heart rate was lower in the ivabradine group than in the control group during the initial CMR (P=0.02) and the follow-up CMR (P=0.006). At the follow-up CMR, there was a smaller increase in LV end-diastolic volume index in the ivabradine group than in the control group (P=0.04). LV end-systolic volume index remained unchanged in the ivabradine group, but increased in the control group (P=0.01). There was a significant improvement in LV ejection fraction in the ivabradine group compared with in the control group (P=0.04).

Conclusions: In successfully reperfused STEMI patients, ivabradine may improve LV remodelling when added to current guideline-based therapy.

Keywords: Imagerie par résonance magnétique nucléaire; Infarctus du myocarde; Ivabradine; Left ventricular remodelling; Magnetic resonance imaging; Myocardial infarction; Remodelage ventriculaire gauche.