β-Blocker-Associated Risks in Patients With Uncomplicated Hypertension Undergoing Noncardiac Surgery

IMPORTANCE Perioperative beta-blocker strategies are important to reduce risks of adverse events. Effectiveness and safety may differ according to patients' baseline risk. OBJECTIVE To determine the risk of major adverse cardiovascular events (MACEs) associated with long-term beta-blocker therapy in patients with uncomplicated hypertension undergoing noncardiac surgery. DESIGN, SETTING, AND PARTICIPANTS Association study based on in-hospital records and out-of-hospital pharmacotherapy use using a Danish nationwide cohort of patients with uncomplicated hypertension treated with at least 2 antihypertensive drugs (beta-blockers, thiazides, calcium antagonists, or renin-angiotensin system [RAS] inhibitors) undergoing noncardiac surgery between 2005 and 2011. INTERVENTIONS Various antihypertensive treatment regimens, chosen as part of usual care. MAIN OUTCOMES AND MEASURES Thirty-day risk of MACEs (cardiovascular death, nonfatal ischemic stroke, nonfatal myocardial infarction) and all-cause mortality, assessed using multivariable logistic regression models and adjusted numbers needed to harm (NNH). RESULTS The baseline characteristics of the 14 644 patients who received beta-blockers (65% female, mean [SD] age, 66.1 [12.0] years) were similar to those of the 40 676 patients who received other antihypertensive drugs (57% female, mean [SD] age, 65.9 [11.8] years). Thirty-day MACEs occurred in 1.3% of patients treated with beta-blockers compared with 0.8% of patients not treated with beta-blockers (P < .001). beta-Blocker use was associated with increased risks of MACEs in 2-drug combinations with RAS inhibitors (odds ratio [OR], 2.16 [95% CI, 1.54-3.04]), calcium antagonists (OR, 2.17 [95% CI, 1.48-3.17]), and thiazides (OR, 1.56 [95% CI, 1.10-2.22]), compared with the reference combination of RAS inhibitors and thiazides. Results were similar for all-cause mortality. Risk of MACEs associated with beta-blocker use seemed especially pronounced for patients at least 70 years old (number needed to harm [NNH], 140 [95% CI, 86-364]), for men (NNH, 142 [95% CI, 93-195]), and for patients undergoing acute surgery (NNH, 97 [95% CI, 57-331]), compared with patients younger than 70 years, women, and patients undergoing elective surgery, respectively. CONCLUSIONS AND RELEVANCE Antihypertensive treatment with a beta-blocker may be associated with increased risks of perioperative MACEs and all-cause mortality in patients with uncomplicated hypertension.