Abstract 16623: Long Term Success Stability and Impact of Balloon Size on Antral Cryo Isolation of Pulmonary Veins
Background: Cryo balloon based antral isolation of the pulmonary veins (pv) is widely used and published in Europe, recently presented in the randomized North American STOP AF trial. In the treatment of paroxysmal atrial fibrillation (af), cryo energy is comparable to radiofrequency energy, but may reduce side effects. This study reports on long term success reliability and impact of balloon size.
Methods: Pv isolation was performed with best fitting 28/23mm balloon (Arctic Front, Medtronic) or both mostly due to mismatch of small veins freezing 6 minutes twice per vein. Residual potentials were eliminated with additional balloon freezes. Patients (p) were followed every three months (m) with 7-day holter and clinical visits, since one year every six months.
Results: We treated 422 p (142 women, mean age 59±11 years, 398 with paroxysmal, 24 persistent af, left atrium 43±5 mm,195 p with lone af,165 hypertension, 62 mild structural heart disease). With a mean number of 2.4±1.1 impulses we isolated all pv with balloon only in 87%, in earlier 13 % with additional touch up. In 164 of the last 367 p (45 %) two balloon sizes were combined. Procedure time decreased to 152±38 min and x ray burden to 24±9 min. Phrenic nerve palsy could be reduced to 1.3% (last 250 p). During a follow up of 12.7±8m and 1.1 procedures per p of 327 p analyzed after a blanking time of 3 m, 82% (267 p) were free of af , with one procedure 73%, with left common ostium 81%. During a follow up of 19.1±8 m success rate of 144 p (FU ≥ 1 year) stabilized at 83%, 67% with one procedure. Comparing the long term efficacy of single large with two balloon size strategy we found significant less recurrence of af (21 versus 39 %, p = 0,002) with two balloons, 27 out of 130 versus 38 out of 97 p, respectively. The difference between single small and single large was p=0.028, between single small and two balloons it was not significant.
Conclusions: Cryo balloon based antral isolation of the pv is associated with a lasting success stability in long term outcome. Due to mismatch of contact area between mostly smaller lower venous antra and a single large balloon the outcome with two balloon strategy seems significantly more efficient. Higher cooling power and improvement of balloon shape will increase the success rate in paroxysmal af.
- © 2010 by American Heart Association, Inc.