Intravenous Metoprolol Versus Diltiazem for Rate Control in Noncardiac, Nonthoracic Postoperative Atrial Fibrillation

Background: Little guidance exists on effective management of postoperative atrial fibrillation (POAF) following noncardiac, nonthoracic (NCNT) surgery. Objectives: The purpose of this study was to identify whether a difference exists between intravenous (IV) metoprolol and diltiazem when used to achieve hemodynamically stable rate control in POAF following NCNT surgery. Methods: This retrospective cohort study examined critically ill adult surgical patients experiencing POAF with rapid ventricular response. Inclusion in the metoprolol or diltiazem treatment group was determined by the initial rate control agent chosen by the prescriber. The primary end point was hemodynamically stable rate control, defined by heart rate (HR) <110 beats/min and blood pressure >90 mm Hg, maintained for 6 hours. Main Results: Patients on metoprolol (n = 66) and diltiazem (n = 55) were similar in age, comorbidities, surgical procedure distribution, acuity of illness, and home rate and rhythm control medications continued during hospitalization; 76% of diltiazem-treated patients achieved hemodynamically stable rate control, compared with only 53% of those receiving metoprolol (P =.005). Safety end points were similar between groups, including the portion requiring a new vasopressor or fluid bolus for hemodynamic support. Conclusions: In NCNT surgery, patients with POAF, IV diltiazem more effectively controlled HR and hemodynamics compared with metoprolol. Results warrant further research into optimal medical management of POAF in this population using these 2 agents.