Beta blockers, stroke, and noncardiac surgery: resolving an enduring perioperative dilemma

An enduring controversy surrounds perioperative beta-blocker use in noncardiac surgery, in particular with regard to the cerebrovascular risks associated with long-term preoperative beta-blocker use. Although perioperative stroke is uncommon, its consequences are severe, and the growing recognition of covert perioperative stroke, affecting up to 7-12% of older patients, substantially magnifies its clinical significance. The debate was shaped principally by the POISE trial, which showed that acute initiation of high-dose extended-release metoprolol reduced myocardial infarction but significantly increased stroke and mortality. Subsequent evidence suggests that stroke risk depends on timing, dose, and drug class rather than beta-blockade per se. Current guidelines support continuation of chronic beta-blocker therapy while discouraging acute perioperative initiation, a position now challenged by emerging data. We discuss the recent findings of Rudolph and colleagues, who used causal inference methods in a large multicentre retrospective cohort of nearly 290 000 patients to show that long-term preoperative beta-blocker prescription was independently associated with increased postoperative ischaemic stroke risk at 30 and 365 days. This association was most pronounced in lower-risk patients and was absent in those with severe heart failure, suggesting important effect modification by baseline cardiovascular status. We explore the pathophysiological mechanisms that could underline this association, address the methodological strengths and limitations of causal inference applied to large observational datasets, and advocate for a nuanced, individualised approach to perioperative beta-blocker management, particularly in patients without established cardiac indications.