Evaluation of β-blocker therapy for long-term outcomes in patients with low ejection fraction after cardiac surgery

Abstract

Abstract Background Preoperative low left ventricular ejection fraction (LVEF) has been reported as an independent risk factor for in-hospital mortality. However, there were few studies evaluating the long-term mortality in these patients. We, therefore, conducted this study to investigate long-term outcomes of surgery on patients with LVEF≤35% undergoing a broad range of cardiac procedures. Methods We performed a retrospective cohort study in 510 patients from January 1, 2007 to September 1, 2019. These patients were divided into survival group (n = 386) and non-survival group (n = 124). The multivariate Cox analysis was used to estimate the risk factors for survival. In Cox analysis, β-blockers were indicated to be associated with long-term mortality. To further address bias, we derived a propensity score predicting the function of β-blockers on survival, and matched 52 cases to 52 controls with similar risk profiles. Results Patients were followed for a median period of 24 months (interquartile range: 11–44 months). Multivariate Cox regression analysis indicated that the non-survival group had higher weight, higher EuroSCORE, more smoking patients, longer time of cardiopulmonary bypass (CPB), more intra-aortic balloon pump (IABP) use, and more patients who always used β-blocker (HR: 2.056, 95%CI:1.236–3.420, P = 0.005) compared with survival group. After propensity matching, the group which always used β-blocker showed higher rate of all-cause death compare with the control group (61.54% vs 80.77%, P = 0.030). Conclusions The risk factors for long-term survival were weight, EuroSCORE, smoking, CPB, IABP, always used β-blockers in patients with LVEF≤35%. The discharge prescription of β-blocker should be cautiously administrated in those patients.