[Which is the preferred perioperative beta-blocker?].

Guidelines on perioperative cardiovascular evaluation and management of patients undergoing non-cardiac surgery recommend initiation of beta-blocker therapy in at-risk patients who are undergoing intermediate- to high-risk surgery. Continuation of therapy in patients already receiving beta-blockers is also recommended. Recent literature, however, reported an increased risk of perioperative cardiovascular mortality among patients who continued with existing beta-blockade; most patients in this study were using metoprolol. There are important pharmacodynamic and pharmacokinetic differences between various beta-blockers, and these differences may explain the differences in clinical effects. Metoprolol has less beta1 receptor affinity compared with atenolol and bisoprolol, and beta1 receptor polymorphisms affect the clinical effects of metoprolol. Furthermore, metoprolol is dependent on activity of the CYP2D6 liver enzyme, which results in clinically important differences in plasma concentration. It is, therefore, wise to follow the European guidelines and to initiate beta-blocker therapy in the perioperative period with either atenolol or bisoprolol.