Impact of beta blockers on perioperative complications in patients undergoing major noncardiac surgery

Abstract

Abstract Introduction Beta blockers (BB) are broadly used in patients with cardiovascular disease because they are known to decrease myocardial oxygen consumption by decreasing heart rate and myocardial contractility. Pilot studies have shown conflicting results. Therefore, we aimed to evaluate the impact of preoperative BB therapy on (1) the incidence of cardiac perioperative myocardial injury/infarction (PMI) within 48 hours after surgery and (2) long-term MACE within 365 days in patients after major noncardiac surgery. Methods We prospectively included consecutive high-risk patients undergoing inpatient major noncardiac surgery at a university hospital and a hospital, both in Switzerland, who were eligible for the institutional active PMI surveillance and response program. The primary endpoint was PMI due to cardiac causes (type 1 myocardial infarction (MI), tachyarrhythmia, acute heart failure, or type 2 MI) within 3 days after surgery, centrally adjudicated by two independent experts. The secondary endpoint was the occurrence of MACE, defined as a composite of acute myocardial infarction, acute heart failure, life-threatening arrhythmia, and cardiovascular death, within 365 days. We used inverse probability of treatment weighting to account for differences between BB and non-BB users and then performed a univariable logistic regression with cardiac PMI and a univariable Cox proportional hazard model with MACE as a dependent variable. Results Between October 2014 and February 2018, we included 7751 high-risk patients undergoing major inpatient noncardiac surgery. The median age was 74 years and 45% were female. 2856 of 7751 patients (36.8%) received preoperative BB therapy. Patients receiving BB therapy had more cardiovascular comorbidities like known coronary artery disease, atrial fibrillation, or hypertension. After IPTW, we achieved a good balance between patients receiving BB therapy and those who did not. 812 patients (10.5%) had a cardiac PMI within 3 days after surgery. When comparing the patients receiving BB to those that did not, we did not see any difference in the occurrence of cardiac PMI, resulting in a weighted odds ratio of 0.99 (95% Confidence interval [CI] 0.89-1.10). The composite secondary endpoint MACE within 365 days occurred in 9% of all patients. In multivariable analysis, there was no difference between patients receiving BB and those that did not, with a weighted hazard ratio of 1.07 (95% CI 0.86-1.33). Conclusion In our patient cohort, we could not see any difference in cardiac PMI between patients receiving BB therapy and those who did not, suggesting that continuing BB perioperatively is safe but not associated with any benefit. Also after 1 year, we saw no difference in MACE between patients receiving BB therapy versus those who did not.MACE within 365 days