Rapid pharmacological cardioversion of recent-onset atrial fibrillation using antazoline in elderly patients.

INTRODUCTION Little is known about the safety and effectiveness of pharmacological cardioversion of recent-onset atrial fibrillation (AF) in the elderly. Antazoline has already been shown to be effective and safe in a wide variety of patients. OBJECTIVES To compare clinical effectiveness and safety of iv antazoline administered for pharmacological cardioversion of recent-onset AF in patients aged ≥75 years and younger. PATIENTS AND METHODS This retrospective analysis was conducted using data derived from emergency room medical records of patients qualified for pharmacological cardioversion due to symptomatic AF lasting less than 48 hours. For the purpose of the analysis the threshold for old age was set at 75 years. Conversion to sinus was considered a primary effectiveness outcome. The primary safety outcome was defined as any adverse event (AE) leading to hospitalization. RESULTS Out of 334 patients, 110 patients ≥75 years old comprised the study group. Successful CV was achieved using smaller doses of antazoline in the study group than in the control group: 151 (59) mg vs. 168 (58) mg (P = 0.039). The effectiveness and safety of antazoline was similar in patients aged ≥75 and <75 years: conversion to sinus - 78.2% vs. 68.3%, OR 1.66 (95%CI: 0.98-1.31), P = 0.06 and hospitalization due to AE - 0.9% v. 4.0%, OR 0.22 (95%CI: 0.03-1.75), P = 0.17. CONCLUSIONS In comparison to younger patients, intravenous antazoline seems to be effective and safe for pharmacological cardioversion of recent-onset atrial fibrillation performed in the emergency department in elderly patients aged ≥ 75 years.