Abstract

The issue of when to cardiovert atrial fibrillation (AF) is controversial. Early cardioversion can help decrease symptom burden and atrial remodeling, whereas delayed or wait-and-see approaches can enable spontaneous conversion and decrease the number of procedures. This systematic review aimed to assess the safety, effectiveness, and resource implications of early versus delayed cardioversion in various populations of AF. A systematic review of randomized trials, observational cohorts, and large administrative datasets of early and delayed cardioversion of patients with paroxysmal, persistent, or recent-onset AF was conducted. The extracted data included study design, population characteristics, early and late cardioversion, AF recurrence, adverse events, length of stay, and resource utilization. A total of 21,587 patients were included in six studies. Delayed strategies proved to be no worse than early cardioversion in rhythm control at short-term follow-up, and 63%-69% of patients spontaneously converted. Studies did not show any significant differences in mortality, thromboembolism, or stroke. Early or emergency cardioversion was linked to reduced AF recurrence, better symptom scores, decreased atrial remodeling, and shorter time to ablation, but delayed cardioversion was linked to reduced cost, length of stay, and risk of acute heart failure. Late-onset AF and stable AF respond well to delayed strategies, but early cardioversion can be better in persistent AF or more at-risk hospitalized patients to minimize recurrence and other adverse hemodynamic impacts. Timing protocols should be standardized, and prospective studies on long-term outcomes should be conducted.

Key words: Outcomes, cardioversion, atrial fibrillation, emergency department, systematic review