Pulmonary Congestion Complicating Atrial Fibrillation Cardioversion

Acute pulmonary congestion (APC) may occur within hours after electrical cardioversion of atrial fibrillation (AF). There is scarce data about its incidence, risk factors, and the outcome. In the present study, data of consecutive patients admitted for first electrical cardioversion for AF between 2007 and 2016 were retrospectively reviewed. APC within the 48 hours following cardioversion was defined as dyspnea and at least one of the following: drop in saturation to <90%, administration of intravenous diuretic or an emergent chest X-ray with new pulmonary congestion. All-cause mortality was determined from the national registry. Total of 1,696 patients had first cardioversion for AF, of whom 66 (3.9%) had APC. In a multivariate logistic regression model independent predictors of APC included (OR [CI], p): older age (odds ratio [OR] 1.05, 95% confidence interval [CI] 1.02 to 1.08, p = 0.001), rapid ventricular response (OR 1.98, 95% CI 1.17 to 3.34, 0.010), previous heart failure (OR 3.53, 95% CI 2.09 to 5.97, p <0.001), Amiodarone loading (OR 2.38, 95% CI 1.18 to 4.79, p = 0.016) and diabetes mellitus (OR 1.77 95% CI 1.05 to 3.00, p = 0.033). There was no difference in cardioversion success rate (overall 94%). In-hospital mortality was 1.5% within the APC group and 0.5% without (p = 0.301). Patients with APC had higher rate of 6-month readmissions (28.8% vs 18.1% p <0.028). Within a median follow-up of 2.9 years, APC following cardioversion was an independent predictor of overall mortality (hazard ratio 1.73, 95% CI (1.17 to 2.56) p = 0.006). In conclusion, APC occurs in 3.9% of hospitalized patients following electrical AF cardioversion. Risk factors include increased age, diabetes mellitus, heart failure, Amiodarone loading and rapid ventricular response. APC following cardioversion is associated with increased rates of readmissions and mortality.