Intravenous diltiazem is superior to intravenous amiodarone or digoxin for achieving ventricular rate control in patients with acute uncomplicated atrial fibrillation.

Author(s): Siu CW, Lau CP, Lee WL, Lam KF, Tse HF

Affiliation(s): Department of Medicine, the University of Hong Kong, Hong Kong, China.

Publication date & source: 2009-07, Crit Care Med., 37(7):2174-9

Publication type: Comparative Study; Randomized Controlled Trial

OBJECTIVES: To compare the clinical efficacy of intravenous diltiazem, digoxin, and amiodarone for acute ventricular rate (VR) control in patients with acute symptomatic atrial fibrillation (AF) necessitating hospitalization. DESIGN: Randomized control trial. SETTING: Acute emergency medical admission unit in a regional teaching hospital in Hong Kong. PATIENTS: One hundred fifty adult patients with acute AF and rapid VR (>120 bpm). INTERVENTIONS: Patients were randomly assigned in 1:1:1 ratio to receive intravenous diltiazem, digoxin, or amiodarone for VR control. MEASUREMENTS AND MAIN RESULTS: The primary end point was sustained VR control (<90 bpm) within 24 hours; the secondary end points included AF symptom improvement and length of hospitalization. At 24 hours, VR control was achieved in 119 of 150 patients (79%). The time to VR control was significantly shorter among patients in the diltiazem group (log-rank test, p < 0.0001) with the percentage of patients who achieved VR control being higher in the diltiazem group (90%) than the digoxin group (74%) and the amiodarone group (74%). The median time to VR control was significantly shorter in the diltiazem group (3 hours, 1-21 hours) compared with the digoxin (6 hours, 3-15 hours, p < 0.001) and amiodarone groups (7 hours, 1-18 hours, p = 0.003). Furthermore, patients in the diltiazem group persistently had the lowest mean VR after the first hour of drug administration compared with the other two groups (p < 0.05). The diltiazem group had the largest reduction in AF symptom frequency score and severity score (p < 0.0001). In addition, length of hospital stay was significantly shorter in the diltiazem group (3.9 +/- 1.6 days) compared with digoxin (4.7 +/- 2.1 days, p = 0.023) and amiodarone groups (4.7 +/- 2.2 days, p = 0.038). CONCLUSIONS: As compared with digoxin and amiodarone, intravenous diltiazem was safe and effective in achieving VR control to improve symptoms and to reduce hospital stay in patients with acute AF.