Left Atrial Volume as Predictor of Recurrence After Pulmonary Vein Isolation: A DECAAF II Substudy

Left atrial volume (LAV) is a known predictor of atrial arrhythmia (AA) recurrence after pulmonary vein isolation (PVI).

The authors sought to assess the role of LAV in predicting AA recurrence and atrial fibrillation (AF) burden in patients with persistent AF (PerAF) undergoing PVI.

The DECAAF-II trial was a prospective randomized controlled trial of PerAF patients undergoing first-time ablation. Patients underwent late gadolinium-enhanced magnetic resonance imaging to calculate baseline LAV and baseline atrial fibrosis. Patients provided single-lead home electrocardiogram strips once daily and upon symptom onset. The primary endpoint was defined as freedom from recurrent AA following a 90-day blanking period through 365 days postprocedure. SMURDEN (Smartphone AF burden) was calculated by dividing the total number of days in AF by the total number of days when strips were sent. A covariate-adjusted Cox regression model was performed to identify independent predictors of success. Univariate and multivariate analysis was performed to predict SMURDEN beyond the 3-month blanking period.

A total of 361 patients with 20.5% females and a mean age of 62 years were analyzed. Median LAV was 129 cc (IQR: 103.9-153.6). ROC analysis identified LAV <114 cc as the optimal cut point for success. In the Cox model, LAV <114 cc was the only significant independent predictor of procedural success with an HR of 0.53 (95% CI: 0.35-0.82, P = 0.04). A multivariate model of traditional risk factors accounted for 12% of the variability in SMURDEN (adjusted R² = 0.12, P < 0.001); only LAV and age remained significantly related.

In patients with PerAF undergoing PVI as the first ablation procedure, LAV is a strong predictor of AA recurrence and SMURDEN. LAV larger than 114 cc was associated with more than a 40% risk of recurrent arrhythmia.