Metoprolol versus diltiazem in the emergency department for atrial fibrillation with rapid ventricular response

Atrial fibrillation (Afib) is the most commonly treated arrhythmia in the Emergency Department (ED). Multiple guidelines recommend the use of intravenous (IV) beta-blocking (BB) agents or nondihydropyridine calcium channel blockers (Non-DHP CCB) as first line agents for heart rate control. Data regarding optimal first line selection between the agents is lacking. The primary objective was to determine whether a clinically significant difference exists in achieving rate control and time to rate control between use of IV metoprolol or diltiazem. This was a dual center, retrospective, cohort, chart review of patients presenting to the ED from January 1, 2015 to March 1, 2020, who received either IV bolus doses of metoprolol or diltiazem for Afib with RVR. Inclusion criteria: ≥18 years of age, received a bolus dose(s) of IV metoprolol or diltiazem for management in the ED, and ECG confirmed diagnosis of Afib based on ICD 9/10 codes. Analyzed 305 patients with 99 patients in the metoprolol group and 206 patients in the diltiazem group. The primary outcome of time to HR ​< ​110 bpm was not statistically significant between metoprolol and diltiazem groups. Rates of adverse events including bradycardia and hypotension were not significantly different. There was no significant difference in the time to adequate heart rate control following administration of IV metoprolol or diltiazem for the treatment of atrial fibrillation with rapid ventricular response.