PALO ALTO, CALIFORNIA. The prevalence of atrial fibrillation among individuals 75 years or older is about 15%. Clearly it is important to answer the question, "Is PVI ablation safe and effective for this age group?" A team of electrophysiologists from the Cleveland Clinic, Marin General Hospital, and the Umberto I Hospital in Italy have pooled their outcome results for a total of 174 patients over 75 years of age who underwent pulmonary vein antrum isolation and isolation of the superior vena cava guided by mapping of electrically active areas and intracardiac echocardiography.
The patients were followed for an average of 20 months by serial event recorder transmissions. The immediate complete success rate (no afib, no antiarrhythmics) was 73%. An additional 16 patients (out of 20) were afib-free after a second procedure (repeat rate of 16%) bringing total success rate to 82%. An additional 18 patients maintained sinus rhythm with the use of previously ineffective antiarrhythmics resulting in a partial success rate of 10%. During the 194 procedures, 1 patient suffered a stroke, 3 experienced groin hematomas, and 1 suffered a hemothorax secondary to right internal jugular vein catheterization. No tamponade, atrial-esophageal fistula, or pulmonary vein stenosis were reported.
During the first 3 months, 3 patients experienced a thromboembolic event despite being on warfarin. However, in 2 cases their INR was below 2.0. In the third case, the patients had the stroke 2 days after undergoing cardioversion and it is suggested that the atrial thrombus (blood clot) was secondary to the atrial stunning that follows direct current cardioversion.
The researchers point out that their common strategy is to discontinue warfarin after 3 months in all patients whose left atrial mechanical function is normal provided they have not experienced recurrence of AF. This would seem to be safe and appropriate since no thromboembolic events were observed over a 16-month period in the group that discontinued warfarin. The conclusion drawn from the study is that, "PVI appears to be a safe and effective treatment strategy for the eradication of AF in septuagenarians. Medium- to long-term success can be achieved in most patients, and the overall rate of complications is low."
Corrado, A, et al. Efficacy, safety, and outcome of atrial fibrillation ablation in septuagenarians. Journal of Cardiovascular Electrophysiology, Vol. 19, August 2008, pp. 807-11
Hurwitz, JL. Atrial fibrillation treatment in the elderly. Journal of Cardiovascular Electrophysiology, Vol. 19, August 2008, pp. 812-14 (editorial comment)
Editor's comment: The finding that pulmonary vein ablation is safe and effective even for patients over the age of 75 years is certainly welcome news. Although the participants in the study did not have lone afib (68% had structural heart disease and 24% coronary artery disease) and 65% had a CHADS score of 2 or higher, there is no reason to believe that the researchers' conclusion would not be applicable to lone afibbers who could perhaps expect an even better outcome.