Pulmonary vein remodeling following pulmonary vein isolation in patients with atrial fibrillation-do pulmonary veins represent only an epiphenomenon? A cardiac MRI study.

Background: After successful pulmonary vein isolation (PVI) for atrial fibrillation (AF), the left atrium (LA) undergoes reverse remodeling. However, few studies have directly studied pulmonary vein (PV) remodeling and focused on whether pre PVI-PV conditions could predict outcome of the procedure. We hypothesize that: (I) post PVI, in addition to LA remodeling the PVs undergo a parallel degree of remodeling; and (II) that PV characteristics pre PVI can be used to identify patients more likely to sustain normal sinus rhythm (NSR).

Methods: Patients (n=100) scheduled for PVI had a cardiovascular magnetic resonance (CMR) imaging before and 6±2 months following PVI. PV cross sectional areas (CSA) within 0.5 cm of the ostium and LA volumes were measured. Patients were categorized as responders (R) or non-responders (NR), based on two separate 14-day Holter monitoring.

Results: PVs CSA were significantly reduced post procedure in both groups, R (233±53 to 192±52 mm, P<0.001) and NR (241±54 to 207±44 mm, P<0.001), however, the difference between R and NR post PVI was not significant (192±52 to 207±44 mm, P=0.19). Reduction in PVs CSAs post procedure moderately correlated with the 3D LA volume reduction (r=0.48, P<0.001).

Conclusions: PVs mirror the LA in that they significantly change in size following PVI yet they were not found to directly predict maintenance of NSR.