Pre-existent left atrial scarring in patients undergoing pulmonary vein antrum isolation: an independent predictor of procedural failure.

OBJECTIVES: The goal of this study was to assess the impact of left atrial scarring (LAS) on the outcome of patients undergoing pulmonary vein antrum isolation (PVAI) for atrial fibrillation (AF).
BACKGROUND: Left atrial scarring may be responsible for both the perpetuation and genesis of AF.
METHODS: A total of 700 consecutive patients undergoing first-time PVAI were studied. Before ablation, extensive voltage mapping of the left atrium (LA) was performed using a multipolar Lasso catheter guided by intracardiac echocardiography (ICE). Patients with LAS were defined by a complete absence of electrographic recording by a circular mapping catheter in multiple LA locations, and this was validated by electroanatomic mapping. All four pulmonary vein antra and the superior vena cava were isolated using an ICE-guided technique. Patients were followed at least nine months for late AF recurrence. Univariate and multivariate analyses were performed to assess the predictive value of LAS and other variables on outcome.
RESULTS: Of 700 patients, 42 had LAS, which represented 21 +/- 11% of the LA surface area by electroanatomic mapping. Patients with LAS had a significantly higher AF recurrence (57%) compared with non-LAS patients (19%, p = 0.003). Also, LAS was associated with a significantly larger LA size, lower ejection fraction, and higher C-reactive protein levels. Univariate analysis revealed age, nonparoxysmal AF, and LAS as predictors of recurrence. Multivariate analysis showed LAS as the only independent predictor of recurrence (hazard ratio 3.4, 95% confidence interval 1.3 to 9.4; p = 0.01).
CONCLUSIONS: Pre-existent LAS in patients undergoing PVAI for AF is a powerful, independent predictor of procedural failure. Left atrial scarring is associated with a lower EF, larger LA size, and increased inflammatory markers.