Don't Wait to Ablate AF: Time Since Diagnosis Affects Ablation Success in Study
Pam HarrisonJanuary 18, 2016
CLEVELAND, OH — The length of time between diagnosis of persistent atrial fibrillation (AF) and catheter ablation has a significant impact on the procedure's success, in that the longer the interval, the worse the outcomes, suggests an analysis from a single but highly experienced center. Longer delays also correlated with increased B-type natriuretic peptide (BNP) and C-reactive protein (CRP) levels.
Once AF has been present a long time, especially in patients with persistent AF, "there is a lot of remodeling, scar formation, and fibrosis in the atrium. And once there is fibrosis and scarring, outcomes are really much worse than in patients who have AF but healthy atria," senior author Dr Oussama Wazni (Cleveland Clinic Foundation, OH) told heartwire from Medscape.
"In this paper we found the sooner, the better," he said. "If a patient has persistent AF and the medications are not working or the patient isn't tolerating the medication well, physicians should not waste too much time with medicines and refer patients to specialized centers where experts can deal with the problem."
The study, published online January 13, 2016 in Circulation: Arrhythmia and Electrophysiology with Dr Ayman A Hussein (Cleveland Clinic) as lead author, was based on a population of patients undergoing radiofrequency ablation for recurrent symptomatic AF from 2005 to 2012 who were enrolled in the center's data registry. They had been followed with scheduled clinical visits and a 12-lead ECG at 3, 6, and 12 months and on a yearly basis thereafter. The current analysis included 1241 patients with persistent AF and no prior AF ablation or cardiac surgery.
The median time between the first diagnosis of persistent AF and the ablation procedure was 3 years; it ranged from 1 year for those in the 25th percentile to 6.5 years for those in the 75th percentile.
Over 90% of patients presented in AF on the day of ablation; in this group, the median time spent in continuous AF prior to ablation was 13 weeks. The median time was as little as 6 weeks for those in the 25th percentile and a median of 34 weeks for those in the 75th percentile. For patients with continuous AF lasting over a year, the median time spent in continuous AF prior to the ablation procedure was 168 weeks.
Over the 2-year follow-up period, 599 patients (48.3%) had AF recurrence, the group reported. Recurrence rates were 33.6% for those in the first quartile of time between diagnosis and ablation; 52.6% for those in the second quartile; 57.1% for those in the third quartile; and 54.6% for those in the fourth quartile (P<0.0001).
Adjusted Hazard Ratio (95% CI) for Recurrence of AF, by Time Since Diagnosis, in 2 Years After Ablation
QuartileHR (95% CI)
1 (≤1 y)Reference
2 (1.1–3.0 y)2.12 (1.43–3.20)
3 (3.1–6.5 y)2.32 (1.59–3.47)
4 (>6.5 y)2.44 (1.68–3.65)
P<0.0001 quartile 4 vs quartile 1
With longer diagnosis-to-ablation times, the group reports patients were more likely to be hypertensive (P<0.0001) and have a larger left atrium (P=0.03). Those with longer intervals between first diagnosis and ablation also had higher BNP levels (P=0.01) as well as higher CRP levels (P<0.0001).
"The first diagnosis of persistent AF marks a critical stage in the natural history of AF, and hence, the importance of the current findings," the group concludes.
The authors reported no relevant financial relationships.