Pulmonary vein stenosis by ostial irrigated-tip ablation: incidence, time course, and prediction

The incidence of pulmonary vein (PV) stenosis and its time course for ostial trigger elimination in paroxysmal atrial fibrillation (PAF) is uncertain. In addition, the clinical value of serial computed tomographic (CT) scanning of the PV ostia and the predictive value of energy requirements for radiofrequency ablation have yet to be established.

We performed irrigated-tip ablation in 37 patients with drug-resistant PAF. Serial spiral CT scans were taken prospectively in 34 patients the day before the procedure, at prehospital discharge, and at 3- and 6-month follow-up. Using a clock model, energy requirements were analyzed for every segment of the PV circumference. One hundred fifteen PVs were targeted in 57 procedures. Compared to baseline, 7 (6.08 %) of 115 PV showed minor (<50%) PV stenosis. Two severe (>90%) PV stenoses (1.73%) were detected with a mean follow-up of 275 +/- 100 days. Luminal narrowing occurred most frequently in the left inferior PV (6/9 stenosed PV). Minor stenosed PVs showed their maximal luminal regression within the 3-month follow-up. Two of two PVs with narrowing >50% at 3 months progressed to high-grade stenosis. Analysis of delivered energy showed no significant correlation with the degree of stenosis. However, for the left inferior PV, more energy was applied in the superior segment of a stenotic PV (6697 +/- 930 J vs 3555 +/- 380 J, P = 0.005).

Assessment of PV diameter by serial spiral CT scanning shows a low incidence of severe stenosis. The left inferior PV is at higher risk. Minor stenosed PV showed no progression after 3 months. Occurrence of stenosis tended to be related to the amount of energy delivered.