P1038Device implantation after catheter ablation of paroxysmal atrial fibrillation with coexisting sick sinus syndrome: Insights from the Kansai Plus Atrial Fibrillation (KPAF) study
Authors: Morishima I , Morita Y , Takagi K , Kanzaki Y , Kobori A , Kaitani K , Inoue K , Kurotobi T , Nagai H , Watanabe N , Furui K , Yoshioka N , Yamauchi R , Tsuboi H , Shizuta S 
Published: October 2019

Abstract

Background
Sick sinus syndrome (SSS) and atrial fibrillation (AF) frequently coexist and interact to initiate and perpetuate each other. Several retrospective or small cohort studies have suggested that successful catheter ablation of AF may help to waive device implantations in patients with paroxysmal AF plus SSS, however, no prospective large studies are so far available on this scenario.

Purpose
We aimed to elucidate the device implantation-free survival after catheter ablation of paroxysmal AF with coexisting SSS in a prospective large-scale registry. We also determined the risk factors for device implantations after catheter ablation of paroxysmal AF.

Methods
The Kansai Plus Atrial Fibrillation (KPAF) study is a multi-center prospective registry that enrolled 5,019 consecutive patients that underwent an initial pulmonary vein isolation-based radiofrequency catheter ablation of AF. This study was comprised of 3,226 patients with paroxysmal AF registered in the KPAF study (age, 64.8±10.5 years old; female, n=999 [31.0%]; left atrial diameter [LAD], 37.5±8.0 mm; left ventricular ejection fraction [LVEF], 65.3±8.4%, CHADS2 score, 1.09±1.05). The atrial tachyarrhythmia-free and device-free survivals after catheter ablation were compared between patients with SSS (n=368; tachy-brady syndrome, 88%) and without SSS (control; n=2,858).

Results
The atrial tachyarrhythmia-free survival was almost identical between the two groups both after the first ablation session (Fig.1A) and after the last procedure with an average of 1.3±0.5 sessions. At baseline, the devices had already been implanted in 53 (14.4%) SSS and 36 (1.3%) control patients. In the remaining patients, devices were newly implanted in 54 (17.1%) SSS and 62 (2.2%) control patients during the follow-up of 3 years after the catheter ablation (Figure 1B). In the SSS group, devices were implanted predominantly within 6 months after the catheter ablation, and atrial tachyarrhythmia recurrence preceded the device implantation in 48 (89%) patients. Multivariate predictors of device implantations after the paroxysmal AF ablation included: SSS (hazard ratio [HR] 6.85, 95% confidence interval [CI] 4.61–10.19, p<0.001), an age>75 years old (HR 1.69, 95% CI 1.08–2.64, p=0.019), a female gender (HR 2.16, 95% CI 1.44–3.24, p<0.001), the LAD (mm) (HR 1.05, 95% CI 1.02–1.08, p=0.006), and the LVEF (%) (95% CI 0.96, 95% CI 0.94–0.98, p<0.001).
Figure 1

Conclusions
Device implantations could be waived in >80% of patients with SSS at 3 years of follow-up after the catheter ablation of paroxysmal AF in this real world all comer prospective registry. In addition to coexisting SSS, predictors of device implantations after paroxysmal AF ablation included: the elderly, a female gender, a large LA, and a reduced LVEF.

Acknowledgement/Funding
None