Ablation outcome in octogenarians

AUSTIN, TEXAS. As the population ages, the question naturally arises, is radiofrequency catheter ablation (RFCA) for the purpose of curing atrial fibrillation (AF) safe and effective in older afibbers, in particular, those over the age of 80 years? A team of experienced electrophysiologists now answer this question.

Their study involved 2754 consecutive AF patients who had undergone one or more ablations during the period 2008 to 2011 at St. David’s Medical Center, Scripps Clinic, California Pacific Medical Center or University of Foggia (all headed by Dr. Andrea Natale). One hundred and three (103) of these patients were older than 80 years (average age of 85 years with 4 patients being older than 90 years). The average age of the remaining 2651 patients was 62 years with 72% being male (only 59% were male in the older group). Other pertinent characteristics of the two groups were:

-
Older Group
Younger Group
Paroxysmal AF
25%
27%
Persistent AF
42%
39%
Permanent AF
33%
34%
Hypertension
48%
37%
Coronary artery disease
15%
11%
Heart failure
17%
10%
CHADS2 score - 0
0%
38%
CHADS2 score - 1
34%
42%
CHADS2 score - 2 or more
66%
20%

The RFCA was carried out under general anesthesia in all patients with an esophageal probe used to monitor esophageal temperature during ablation in order to avoid creating an atrioesophageal fistula. Patients with paroxysmal AF underwent pulmonary vein antrum isolation and isolation of the superior vena cava. In patients with persistent and permanent (long-standing persistent) AF, the electrical isolation of the pulmonary veins was extended to the entire posterior wall down to the coronary sinus and the left side of the septum. Ablation of complex fractionated electrograms in the left atrium and in the coronary sinus was also performed. Finally, a 15 to 20 minute challenge with high-dose isoproterenol was performed to check for lesion gaps and any such gaps were re-ablated.

Total procedure, fluoroscopy, and RF times did not differ between the two groups; however, triggers located outside the pulmonary veins were significantly more common (62%) in the older group than in the younger group. Non-pulmonary triggers were significantly more common among persistent and permanent afibbers, but their percentage in the older group (92%) was not significantly higher than in the younger group (87%).

Oral anticoagulant therapy with adjusted-dose warfarin was continued for up to 6 months to maintain the INR between 2 and 3. After this period, warfarin was discontinued, regardless of the CHADS2 score, if patients did not undergo isolation of the left atrial appendage and did not experience any recurrence of atrial tachyarrhythmias, severe pulmonary vein stenosis, or severe left atrial mechanical dysfunction.

After a mean follow-up of 18 months, 69% of the octogenarians remained free from AF recurrence without the use of antiarrhythmics. This single procedure success rate was not significantly different from the 71% complete success rate observed in the younger group. A total of 21 of 32 octogenarians with AF recurrence after the first procedure underwent a repeat procedure after a failed challenge with antiarrhythmic drugs. After a mean follow-up of 9 months, 90% of the repeat ablates were in normal sinus rhythm, bringing the complete success rate to 87% after an average 1.2 ablations. The final success rate in the younger group was 85%.

Warfarin was discontinued in 49 of 71 octogenarians (69%) achieving long-term freedom from AF recurrence after a single procedure, corresponding to 48% of the entire elderly population. The reason for continuing warfarin in the remaining 22 patients (31%) was left atrial appendage isolation during the index procedure. No patients died and none experienced a stroke/TIA during the procedure itself or during the follow-up period. Santangeli, P, Natale, A, et al. Catheter ablation of atrial fibrillation in octogenarians: safety of outcomes. Journal of Cardiovascular Electrophysiology, April 11, 2012 [Epub ahead of print]
Kim, MH. Catheter ablation of atrial fibrillation in octogenarians: the right “medicine”? Journal of Cardiovascular Electrophysiology, April 11, 2012 [Epub ahead of print]

Editor’s comment: It is indeed encouraging that age is no obstacle to having a safe and successful radiofrequency catheter ablation. A final average success rate of 87% after an average 1.2 ablations is also most impressive, particularly when considering that 75% of the older patients had persistent or permanent AF. However, when considering the results it should be kept in mind that they were obtained by the most skilled group of EPs in the United States and are unlikely to be repeatable at “your neighbourhood” ablation facility.