Abstract and Introduction
Abstract
Background: Perioperative β-blocker therapy has been associated with increased risk of stroke. However, the association between β-blocker initiation before the day of surgery and the risk of stroke is unknown. The authors hypothesized there would be no association between preoperative β-blocker initiation within 60 days of surgery or chronic β-blockade (more than 60 days) and the risk of stroke in patients undergoing major abdominal surgery.
Methods: Data on elective major abdominal surgery were obtained from the IBM (USA) Truven Health MarketScan 2005 to 2015 Commercial and Medicare Supplemental Databases. Patients were stratified by β-blocker dispensing exposure: (1) β-blocker–naïve, (2) preoperative β-blocker initiation within 60 days of surgery, and (3) chronic β-blocker dispensing (more than 60 days). The authors compared in-hospital stroke and major adverse cardiac events between the different β-blocker therapy exposures.
Results: There were 204,981 patients who underwent major abdominal surgery. β-Blocker exposure was as follows: perioperative initiation within 60 days of surgery for 4,026 (2.0%) patients, chronic β-blocker therapy for 45,424 (22.2%) patients, and β-blocker–naïve for 155,531 (75.9%) patients. The unadjusted frequency of stroke for patients with β-blocker initiation (0.4%, 17 of 4,026) and chronic β-blocker therapy (0.4%, 171 of 45,424) was greater than in β-blocker–naïve patients (0.2%, 235 of 155,531; P < 0.001). After propensity score weighting, patients initiated on a β-blocker within 60 days of surgery (odds ratio, 0.90; 95% CI, 0.31 to 2.04; P = 0.757) or on chronic β-blocker therapy (odds ratio, 0.86; 95% CI, 0.65 to 1.15; P = 0.901) demonstrated similar stroke risk compared to β-blocker–naïve patients. Patients on chronic β-blocker therapy demonstrated lower adjusted risk of major adverse cardiac events compared to β-blocker–naïve patients (odds ratio, 0.81; 95% CI, 0.72 to 0.91; P = 0.007), despite higher unadjusted absolute event rate (2.6% [1,173 of 45,424] vs. 0.6% [872 of 155,531]).
Conclusions: Among patients undergoing elective major abdominal surgery, the authors observed no association between preoperative β-blocker initiation within 60 days of surgery or chronic β-blocker therapy and stroke.
Introduction
Major adverse cardiac events after major noncardiac surgery are a significant cause of perioperative morbidity and mortality. Recent estimates of major adverse cardiac events suggest a frequency between 1.4 and 3.9%, with an associated in-hospital mortality between 10 and 65%.[1,2] Few preventative measures have proven effective to reduce the risk of these perioperative major adverse cardiac events. Perioperative β-blocker therapy initiated within hours before surgery has been shown to reduce the frequency of myocardial infarction and in-hospital mortality in small randomized controlled trials.[2–5] As a result, β-blockers were incorporated into the American College of Cardiology (Washington, D.C.) and American Heart Association (Dallas, Texas) practice guidelines and further supported by the Surgical Care Improvement Project Card-2 measure that encouraged administration of a β-blocker within a day of surgery if the patient had been on a β-blocker previously.[6] The Perioperative Ischemic Evaluation Study (POISE) demonstrated that aggressive β-blocker initiation within 2 to 4 h of surgery was associated with a greater risk of acute stroke and all-cause mortality, despite a reduction in the frequency of myocardial infarction.[7] The POISE trial studied high-dose β-blocker initiation hours before surgery in β-blocker–naïve patients who were at an increased risk for major adverse cardiac events. After POISE, there was a significant reduction in new β-blocker prescriptions within 60 days of major noncardiac surgery.[8,9] Despite this apparent practice change, the effect of β-blocker initiation in the weeks before major noncardiac surgery on the risk of stroke or major adverse cardiac events in routine practice remains unknown.[10] Further, the effects of chronic β-blocker dispensing (more than 60 days before surgery) on perioperative stroke in noncardiac surgery is unclear in the current literature.[11]
Our study had 2 main aims. The first aim was to identify whether preoperative β-blocker initiation within 60 days of elective major abdominal surgery was associated with higher risk of stroke or lower risk of perioperative major adverse cardiac events. The second aim was to determine whether chronic β-blocker dispensing (more than 60 days before surgery) before elective major abdominal surgery was associated with higher risk of stroke or lower risk of perioperative major adverse cardiac events. We hypothesized that neither preoperative β-blocker initiation within 60 days of surgery nor chronic β-blocker dispensing (more than 60 days before surgery) would be associated with a higher risk of stroke or with a lower risk of major adverse cardiac events.
Anesthesiology. 2023;138(1):42-54. © 2023 American Society of Anesthesiologists | Lippincott Williams & Wilkins