Predictors of Luminal Loss in Pulmonary Veins After Radiofrequency Ablation

The reported incidences of stenosis after radiofrequency ablation of pulmonary veins are highly variable. Moreover, most studies have focused on severe stenosis and have overlooked mild stenosis. Our aims were to study postablation morphological changes in the pulmonary veins and to evaluate preablation magnetic resonance imaging predictors for stenosis.

Eighty consecutive patients with atrial fibrillation underwent cardiac magnetic resonance imaging before undergoing radiofrequency ablation. Magnetic resonance imaging was repeated a median of 95 days after ablation. Ostium area/ellipticity and atrial volume were blindly assessed. We evaluated the presence of stenosis and classified it as mild (< 50% area reduction), moderate (50%-70%), and severe (> 70%).

Postablation stenosis was identified in 78 of 322 veins (24.2%). The stenosis was mild in 66 (84.6%), moderate in 11 (14.1%), and severe in 1 (1.3%). All of them were asymptomatic. The left inferior pulmonary vein showed the highest frequency of stenosis, which was detected in 26% of them (P < .001). A multiple regression analysis revealed that left inferior pulmonary vein (odds ratio = 3.089; P = .02) and a greater preablation ostium area (odds ratio = 1.009; P < .001) were independent predictors for postablation stenosis. Age (odds ratio = 1.033) showed a strong trend to statistical significance (P = .06).

After ablation, vein ostia size is reduced and stenosis is detected in less than one third of patients. Most cases are mild, and severe stenosis is rare. Postablation stenosis is more likely to develop in older patients, those with larger vein ostia, and in the left inferior pulmonary veins.