Long-term outcomes after catheter ablation for idiopathic atypical atrial flutter

Abstract

Background

Idiopathic atypical (non-cavotricupid isthmus [CTI]-dependent) atrial flutter (IAAFL) may be seen in patients without structural heart disease and without previous cardiac surgery or ablation.

Objective

This study sought to determine the patient characteristics, electrophysiological and electroanatomic properties, and clinical outcomes after ablation in patients with IAAFL.

Methods

We retrospectively compared IAAFL patients to CTI-dependent AFL (C-AFL) patients undergoing catheter ablation. The primary outcome was a composite of death from cardiovascular causes, ischemic stroke, and hospitalization for worsening of heart failure.

Results

Among 180 patients who underwent catheter ablation for AFL, 89 were included in this study (22 IAAFL and 67 C-AFL). Electrophysiological study showed significantly longer intra-atrial conduction time, lower atrial voltage during sinus rhythm in the IAAFL group compared to the C-AFL group. The atrial scar was observed in all 22 IAAFL patients, with the most common sites being the posterior or lateral wall of RA in 10 (45.5 %) and the anterior wall of LA in 8 (36.4 %). During 3.5 ± 2.8 years of follow-up, the composite primary endpoint occurred significantly more frequently in the IAAFL group (hazard ratio [HR] 3.45, 95 % confidence interval [CI] 1.20-9.89, P=0.015). In multivariable analysis, brain natriuretic peptide (BNP) levels (HR 1.01, 95 % CI 1.00-1.01, per 1 pg/mL, P=0.01) and IAAFL (HR 4.14, 95% CI 1.21-14.07, P=0.02) were independently associated with the primary outcome.

Conclusions

IAAFL in patients had distinct electrophysiologic features suggestive of atrial cardiomyopathy. These patients are at risk of developing cardiovascular adverse events after ablation.