Association of superior vena cava isolation with improved outcomes in atrial fibrillation ablation

Abstract

Abstract Background Pulmonary vein isolation (PVI) is the mainstay in atrial fibrillation (AF) ablation. However, additional arrhythmogenic foci seem to contribute to AF initiation and maintenance. A great proportion of those non-PV foci have been reported to be located in the superior vena cava. Purpose We aimed to investigate the effectiveness of SVC isolation as an adjunctive therapy to PVI isolation. Methods We performed a systematic review of MEDLINE, CENTRAL, and Embase. Inclusion criteria were cohort studies with control group or randomized clinical trials, comparing patients undergoing PVI only and patients undergoing PVI with concurrent SVC isolation, in effects of freedom from atrial tachycardia, need for cardioversion, hospitalization and all-cause mortality. Results A total of 7 studies, incorporating 1.550 patients, were included. The combination of SVC and PVI isolation in patients undergoing AF ablation was more effective than PVI isolation alone (risk ratio = 0.689; 95% confidence interval, 0.505-0.942). In a subgroup analysis, the isolation of SVC after identifying focal potentials demonstrated effectiveness (risk ratio = 0.573; 95% confidence interval, 0.364-0.902), while the isolation of SVC when the focal potentials were induced after isoprotenerol infusion or rapid atrial pacing did not alter the clinical outcomes (risk ratio = 0.798; 95% confidence interval, 0.493, 1.292). Conclusions The outcomes of AF ablation are favorable when additional SVC isolation is conducted. The effect is pronounced when spontaneous SVC potentials are identified.