Predictors of successful at-home chemical cardioversion in new-onset atrial fibrillation.

Prehospital treatment of new-onset supraventricular arrhythmias can be attempted by physician-staffed mobile intensive care units to decrease the hospitalization rate and expense. Identification of patients suitable for at-home pharmacological treatment may help in the triage of patients with new-onset atrial fibrillation (AF). In the present investigation, the value of several clinical variables to predict the success of pharmacological at-home cardioversion was tested. A total of 924 patients with new onset (less than 24 h) AF, rescued by the Florence Mobile Coronary Care Unit (MCCU), were included in the study. By univariate analysis, female sex, palpitations as symptoms leading to MCCU call and a short delay between symptom onset and MCCU intervention were associated with a favourable outcome of treatment, whilst dyspnoea as the main complaint requiring MCCU intervention and the association of AF with an acute cardiovascular event (angina, acute myocardial infarction or pulmonary oedema) were negatively associated with the success rate of treatment. The cardioversion rate was not significantly different in patients with underlying heart disease or in patients with lone atrial fibrillation. By multivariate analysis, only sex and the drug employed for treatment (positive relation for propafenone and bunaftine, negative for amiodarone, digoxin and verapamil) were significant predictors of the outcome of MCCU intervention. Our results suggest that patients with new-onset (less than 24 h) AF with or without underlying heart disease whose main complaint is palpitation can be successfully cardioverted at home with a class IC drug (propafenone). Patients with acute coronary syndromes or left ventricular failure are good candidates for elective cardioversion after hospitalization.