Beta-blockers in noncardiac surgery: Did observational studies put us back on safe ground?

Based on landmark trials, international guidelines had for years promoted the use of beta-blockers in the setting of non-cardiac surgery. In 2011, concerns were raised regarding the integrity of some of the landmark trials, as the Dutch Erasmus Medical Center found some of them to be scientifically incorrect. Based on the remaining studies that were to be trusted, investigations showed that, in contrast to prior beliefs, the widespread use of perioperative beta-blockers might be harmful. A call for further investigations into the matter ushered in several observational studies evaluating the safety of perioperative beta-blocker therapy in specific patient subgroups. Within this review, we discuss important aspects for making these decisions, and compare the major observational studies and specific estimates of risk in subgroups of interest. We conclude that patients at high risk with heavy co-morbidities, such as heart failure, may benefit from beta-blocker therapy, whereas low-risk patients, such as patients with uncomplicated hypertension, may be at increased risk with beta-blocker therapy. We provide a critical review of current perioperative guidelines in view of the new observational data, suggesting that the recommended schematics, such as the Revised Cardiac Risk Index, for risk stratification of patients in this setting may be suboptimal. Further, we provide discussions of other aspects, including risk of sepsis, type of beta-blocker, and the potential of perioperative beta-blocker withdrawal, which may be important in guiding future studies. Summarising the current evidence, we argue that, after a precarious decade, we may just now, be back on safe ground.