Long-term clinical outcomes of beta-blocker therapy in elderly patients with preserved left ventricular function after percutaneous coronary intervention for acute myocardial infarction

Background The benefit of beta-blocker therapy in elderly patients without left ventricular systolic dysfunction (LVSD) following percutaneous coronary intervention (PCI) for acute myocardial infarction (MI) remains unclear. Moreover, data regarding the long-term clinical outcomes associated with beta-blocker use in this specific population are limited. Purpose This study aimed to evaluate the long-term clinical impact of beta-blocker therapy in elderly patients who underwent PCI for acute MI and had no evidence of LVSD. Methods Among 13,104 patients with acute MI who underwent PCI and were enrolled in a nationwide, prospective, real-world registry, 2,566 elderly patients (defined as ≥70 years) without LVSD (defined as EF ≥50%) were included in the analysis. Of these, 2,063 patients received beta-blockers, whereas 503 did not. The primary outcome was major adverse cardiac events (MACE), defined as a composite of cardiac death, recurrent MI, any revascularization, readmission due to heart failure (HF), stroke, or definite/probable stent thrombosis (ST). MACE and its individual components were compared using multivariable Cox proportional hazards models, propensity score (PS) matching, and PS-adjusted analyses. Results Over a median follow-up duration of 998 days, MACE, all-cause mortality, and cardiac mortality occurred in 560 (21.8%), 374 (14.6%), and 224 (8.7%) patients, respectively. The beta-blocker group demonstrated significantly lower rates of MACE (entire cohort: 20.9% vs. 25.4%, hazard ratio [HR] 0.66, 95% confidence interval [CI] 0.58–0.76, p=0.03; PS-matched cohort: n=986, 20.3% vs. 25.8%, HR 0.69, 95% CI 0.61–0.78, p<0.001), all-cause mortality (entire cohort: 12.9% vs. 21.5%, HR 0.55, 95% CI 0.44–0.69, p<0.001; PS-matched cohort: 11.8% vs. 20.9%, HR 0.58, 95% CI 0.47–0.72, p<0.001), and cardiac mortality (entire cohort: 7.7% vs. 13.1%, HR 0.54, 95% CI 0.41–0.72, p<0.001; PS-matched cohort: 7.3% vs. 13.5%, HR 0.57, 95% CI 0.43–0.79, p<0.001) compared with the no beta-blocker group. There were no significant differences between the two groups in the risks of recurrent MI, any revascularization, readmission due to HF, stroke, or definite/probable ST. The reduced risk of MACE associated with beta-blocker use was consistently observed across predefined subgroups. In patients aged ≥80 years, beta-blocker therapy was associated with numerically lower rates of MACE, all-cause death, cardiac death, recurrent MI, any revascularization, readmission due to HF, stroke, and definite/probable ST compared with no beta-blocker therapy, but insignificantly. Conclusions In this nationwide registry, beta-blocker therapy was associated with improved long-term clinical outcomes compared with no beta-blocker use in elderly patients without LVSD following PCI for acute MI.