RESUMEN
INTRODUCTION: Acute heart rate control for atrial fibrillation (AF) with rapid ventricular response (RVR) in the emergency department (ED) is often achieved utilizing intravenous (IV) non-dihydropyridine calcium channel blockers (CCB) or beta blockers (BB). For patients with concomitant heart failure with a reduced ejection fraction (HFrEF), the American Heart Association and other clinical groups note that CCB should be avoided due to their potential negative inotropic effects. However, minimal evidence exists to guide this current recommendation. The primary objective of this study was to compare the incidence of adverse effects in the HFrEF patient population whose AF with RVR was treated with IV diltiazem or metoprolol in the ED. METHODS: This single center, retrospective review included patients ≥18 years old with HFrEF who presented in AF with RVR and received IV diltiazem or metoprolol in the ED. The primary outcome was adverse effects of therapy defined as: 1) hypotension (systolic blood pressure < 90 mmHg requiring fluid bolus or vasopressors) or bradycardia (heart rate < 60 beats/min) within 60 min of medication administration 2) worsening heart failure symptoms defined as increased oxygen requirements within four hours or inotropic support within 48 h. Secondary outcomes included the incidence of rate control failure, patient disposition, ED length of stay, hospital length of stay, and in-hospital mortality. RESULTS: One hundred and twenty-five patients met inclusion criteria, with 57 receiving diltiazem and 68 receiving metoprolol. Overall adverse effects for diltiazem and metoprolol were similar (32% vs. 21%, P = 0.217). However, there was a significantly higher incidence of worsening heart failure symptoms within the diltiazem group (33% vs 15%, P = 0.019). Rate control failure at 60 min did not differ significantly between diltiazem and metoprolol (51% vs 62%, P = 0.277). CONCLUSIONS: In HFrEF patients with AF, there was no difference in total adverse events in patients treated with IV diltiazem compared to metoprolol. However, the diltiazem group had a higher incidence of worsening CHF symptoms defined as increased oxygen requirement within four hours or initiation of inotropic support within 48 h.