Differing effects of beta-blockers on long-term clinical outcomes following percutaneous coronary intervention between patients with mid-range and reduced left ventricular ejection fraction.

BACKGROUND

The aim of this study was to determine the difference in effects of beta-blockers on long-term clinical outcomes between ischemic heart disease (IHD) patients with mid-range ejection fraction (mrEF) and those with reduced ejection fraction (rEF).

METHODS

Data were assessed of 3508 consecutive IHD patients who underwent percutaneous coronary intervention (PCI) between 1997 and 2011. Among them, 316 patients with mrEF (EF = 40-49%) and 201 patients with rEF (EF < 40%) were identified. They were assigned to groups according to users and non-users of beta-blockers and effects of beta-blockers were assessed between mrEF and rEF patients, separately. The primary outcome was a composite of all-cause death and non-fatal acute coronary syndrome.

RESULTS

The median follow-up period was 5.5 years in mrEF patients and 4.3 years in rEF patients. Cumulative event-free survival was significantly lower in the group with beta-blockers than in the group without beta-blockers in rEF (p = 0.003), whereas no difference was observed in mrEF (p = 0.137) between those with and without beta-blockers. In the multivariate analysis, use of beta-blockers was associated with reduction in clinical outcomes in patients with rEF (hazard ratio (HR), 0.59; 95% confidence interval (CI), 0.36-0.97; p = 0.036), whereas no association was observed among those with mrEF (HR 0.74; 95% CI 0.49-1.10; p = 0.137).

CONCLUSIONS

Our observational study showed that use of beta-blockers was not associated with long-term clinical outcomes in IHD patients with mrEF, whereas a significant association was observed in those with rEF.