Maintaining sinus rhythm after electrical cardioversion

Abstract

Abstract Introduction Atrial fibrillation (AF) and atrial flutter (AFL) are commonly terminated by electrical cardioversion (EC) when a rhythm control strategy is adopted. However, the long-term success following EC is variable. Purpose To determine the clinical characteristics and independent predictors of sinus rhythm (SR) maintenance after EC due to AF/AFL. Methods We conducted a retrospective study enrolling patients with AF/AFL referred to EC in our Cardiology Department, from September 2011 to September 2020. Clinical characteristics and echocardiographic studies were analysed. Primary endpoints were the incidence of ischemic stroke, all-cause and cardiovascular (CV) mortality. Independent predictors of SR maintenance were identified through a binary logistic regression analysis, considering p=0,05. Results A total of 719 patients with a median age of 67 years-old were included, and EC was successfully performed in 93,2%. AFL was diagnosed in 21%, 57,3% had arterial hypertension and 34,6% were obese. 62,1% had persistent AF/AFL, 19,6% presented with first diagnosed AF/AFL and 17,2% had paroxysmal episodes. Left ventricular ejection fraction (LVEF) was preserved in 66,7%. Maintenance of SR after one-year was documented in 64,7% of patients with successful EC. They had lower prevalence of chronic kidney disease (CKD) (2,6% vs 10,7%; p<0,001) and received less electrical shocks during EC (1,20 vs 1,39; p=0,005). There were no differences regarding antiarrhythmic therapy between both groups. Complete LVEF recovery after EC was more frequent in patients who maintained SR (58,8% vs 31,9%; p=0,008), with a greater prevalence of preserved LVEF after EC (88,8% vs 73,6%; p<0,001). During a median follow-up of 1368 days, these patients performed less additional EC (0,26 vs 0,65; p<0,001) and were less referred to ablation procedures (7,1% vs 15,1%; p=0,011). No differences were found regarding stroke rate, but all-cause mortality (12,8% vs 25%; p=0,002) and CV death (3,8% vs 10,9%; p=0,005) were significantly lower in patients who maintained SR. Absence of CKD (p=0,013), applying fewer electric shocks during EC (p=0,013) and preserved LVEF after EC (p=0,004) were independent predictors of SR maintenance. Conclusion In our study, most patients maintained SR one year after EC, which was associated with a lower all-cause and CV mortality. Absence of CKD, applying fewer electric shocks during EC and preserved LVEF after EC were independent predictors of SR maintenance. Funding Acknowledgement Type of funding sources: None.