Clinical question: Does the mortality rate differ between patients treated perioperatively with atenolol versus metoprolol?
Background: Perioperative beta-blockers have been shown to reduce mortality in patients with significant cardiac risk factors. Different beta-blockers have been used in the studies demonstrating benefit, and it is uncertain which beta-blocker is the preferred agent. The purpose of this study was to compare the perioperative benefits of metoprolol versus atenolol.
Study design: Retrospective cohort study.
Setting: San Francisco Veterans Affairs Medical Center.
Synopsis: Computerized records of patients who underwent surgery from 1996 to 2008 were extracted into a database, and patients who received inpatient beta-blockers after surgery were included. Of these patients, 3,787 received beta-blockade exclusively with either atenolol (n=1,011) or metoprolol (n=2,776) during hospitalization. Perioperative risk reduction was better with atenolol versus metoprolol. Mortality rates were 1% versus 3% at 30 days (P=0.0008), and 7% versus 13% at one year (P=<0.0001) with atenolol and metoprolol, respectively. Similar results were found in the analysis of 1,871 patients who were on their respective beta-blocker as an outpatient before surgery.
Because the metoprolol group had higher prevalence of risk factors, such as coronary artery disease, peripheral vascular disease, and congestive heart failure, a propensity-matched analysis was performed to remove differences in risk factors between the groups. After propensity matching, the metoprolol group still had statistically significant higher mortality at 30 days and one year, even though causality cannot be established in this retrospective study.
Bottom line: Atenolol was associated with fewer cases of perioperative mortality compared with metoprolol in patients with cardiac risk factors or established cardiovascular disease.
Citation: Wallace AW, Au S, Cason BA. Perioperative ß-blockade: atenolol is associated with reduced mortality when compared to metoprolol. Anesthesiology. 2011;114:824-836.
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