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

Background — Although practice guidelines recommend that perioperative beta-blockade be initiated at least several days to weeks before non-cardiac surgery, 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 non-cardiac surgery in Ontario, Canada and received preoperative beta-blocker therapy. We used multivariable logistic regression to determine the association of duration of preoperative beta-blocker treatment (classified as one to seven days, eight to 30 days, and ≥31 days) with 30-day mortality, 30-day myocardial infarction, 30-day ischemic stroke, and one-year mortality.

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

Conclusions — Initiation of beta-blocker therapy one to seven days before non-cardiac surgery is associated with increased 30-day mortality. The findings merit further evaluation by randomized trials. In this population-based study of 48,103 patients who underwent major elective non-cardiac surgery in Ontario, Canada, seven or fewer days of preoperative beta-blocker therapy was associated with increased 30-day mortality when compared to individuals who received 31 or more days of preoperative therapy. There was no statistically significant difference in 30-day mortality between individuals who received 8 to 30 days of preoperative beta-blocker therapy versus those who received 31 or more days of preoperative therapy.