Duration of preoperative β-blockade and outcomes after major elective noncardiac surgery.

BACKGROUND: Although practice guidelines recommend that perioperative β-blockade be initiated at least several days to weeks before noncardiac surgery is performed, the minimum required period of preoperative therapy is unclear.

METHODS: Population-based administrative databases were used to conduct a cohort study of 48,103 patients aged ≥ 66 years who underwent major elective noncardiac surgery in Ontario, Canada and received preoperative β-blocker therapy. We used multivariable logistic regression to determine the association of duration of preoperative β-blocker treatment (classified as 1-7 days, 8-30 days, and ≥ 31 days) with 30-day mortality, 30-day myocardial infarction (MI), 30-day ischemic stroke, and 1-year mortality.

RESULTS: The duration of preoperative β-blocker treatment was 1-7 days in 1105 patients (2.3%), 8-30 days in 2639 patients (5.5%), and ≥ 31 days in 44,269 patients (92.0%). Compared with ≥ 31 days of preoperative therapy, 1-7 days of therapy was associated with increased 30-day mortality (odds ratio [OR], 1.49; 95% confidence interval [CI], 1.03-2.16; P = 0.03], whereas 8-30 days of therapy was not (OR, 0.95; 95% CI, 0.69-1.31; P = 0.77). One to 7 days of preoperative therapy was not significantly associated with 1-year mortality (OR, 1.06; 95% CI, 0.84-1.35; P = 0.62), 30-day MI (OR, 1.26; 95% CI, 0.92-1.71; P = 0.15), or 30-day ischemic stroke (OR, 1.37; 95% CI, 0.64-2.94; P = 0.41).

CONCLUSIONS: Initiation of β-blocker therapy 1-7 days before noncardiac surgery is associated with increased 30-day mortality. The findings merit further evaluation by randomized trials.