Effect of ivabradine on cardiovascular outcomes in patients with stable angina: meta-analysis of randomized clinical trials

Although there are established drugs for treatment of cardiovascular diseases, due to adverse effects these drugs may not be clinically applicable to all patients. Recent trends have seen the emergence of drugs which act on funny current channels to induce selective heart rate reduction. Ivabradine is one such drug developed for coronary artery disease and heart failure. There is inconsistent evidence about the effect of this selective inhibitor in reduction of cardiovascular related mortality and morbidity. Such an inconsistency warrants the need for a meta-analysis to consider the effectiveness and efficacy of Ivabradine in the treatment of coronary artery disease and heart failure.

Randomized controlled trials with a minimum follow-up period of one year were searched in Pub Med/Medline, Embase, Cochrane Central Register of Controlled Trials published between 1980 and 2016.Each eligible study was assessed for risk of bias by using the Cochrane Risk of Bias Assessment tool. The outcomes assessed in this study included: all cause mortality, cardiovascular-related mortality, hospitalization for new or worsening heart failure, and adverse events. Subgroup analysis and publication bias were assessed. We used Mantel-Haenszel method for random-effects. Analysis was done using RevMan5.1™.This study was registered in PROSPERO as [PROSPERO 2016:CRD42016035597].

Three trials with a total of 36,577 participants met the meta-analysis criteria. Pooled analysis showed that ivabradine is not effective in reducing cardiovascular deaths (OR: 1.02; CI:0.91–1.15,P = 0.74), all-cause mortality (OR:1.00; CI:0.91–1.10,P = 0.98), coronary revascularization (OR: 0.93, CI: 0.77–1.11, P = 0.41) and hospital admission for worsening of heart failure (OR: 0.94, CI: 0.71–1.25, P = 0.69). However, the drug was found to significantly increase adverse events: phosphenes (OR:7.77, CI: 4.4–14.6,P < 0.00001), blurred vision (OR:3.07,CI:2.18–4.32,P < 0.00001), symptomatic bradycardia (OR: 6.23, CI: 4.2–9.26, P < 0.00001), and atrial fibrillation (OR: 1.35, CI: 1.19–1.53, P < 0.0001). Subgroup analysis by duration of follow up on cardiovascular outcomes found that there is no difference in effect of ivabradine depending on the duration of follow up. There was no publication bias in reporting of included studies.

This meta-analysis suggests that ivabradine is not effective in reducing cardiovascular-related morbidity and mortality unless used for specific conditions. On the contrary, the use of this drug was strongly associated with the onset of untoward and new adverse events. This finding strongly supports previous findings and further informs the rational and evidence-informed clinical use of ivabradine.