HOUSTON, TEXAS. There is now abundant proof that catheter ablation is associated with a significantly better outcome than antiarrhythmic therapy when it comes to the treatment of atrial fibrillation (AF). There is also proof that the outcome of catheter ablation is better the sooner it is done and that trying antiarrhythmics prior to ablation may actually be counterproductive.

Despite this evidence many older AF patients are often treated solely with antiarrhythmics or rate control drugs, and thus denied the benefits of normal sinus rhythm (NSR). Two researchers from Methodist Hospital in Houston now provide evidence that the outcomes of catheter ablation in the elderly are similar to those achieved in younger patients. They cite five studies to support their contention.

• Corrado, et al. (2008) reported an average single-procedure success rate of 73% in 174 patients above the age of 75 years after a 20-month follow-up. Major and minor complications were reported in 1% and 1.5% of patients respectively.
• Bunch, et al. (2010) reported a one-year success rate (no AF or flutter without the use of antiarrhythmics) of 78% in patients 80 years or older as compared to 75% in patients younger than 80 years. There was no difference in complication rate and mortality between the two groups.
• Zado, et al. (2008) compared ablation outcome in three groups – age less than 65 years (948 patients), age between 65 and 74 years (185 patients), and age 75 years or older (32 patients). There was no significant difference between the three groups when comparing outcome and rate of major complications. Success rates in the groups were 89%, 84% and 86% respectively (no AF with or without antiarrhythmics). However, more patients in the oldest group (37%) than in the youngest group (20%) required antiarrhythmics to maintain NSR.
• Bhargava, et al. (2004) demonstrated equal benefits of catheter ablation in three age groups – younger than 50 years, 51 to 60 years, and over 60 years (including patients up to 79 years of age). Success rates of the 1-year follow-up were 85%, 83% and 82% respectively.
• Traub, et al. (2009) compared the outcome of pulmonary vein isolation in 15 patients over the age of 70 years and 45 patients below the age of 70, and found no difference in outcome or complication rates.

AV node ablation and pacemaker installation is another option for treating AF and is particularly favoured for elderly patients as it is relatively simple to perform. The researchers cite two studies that compared AV node ablation with pulmonary vein isolation (PVI).

• Khan, et al. (2008) compared the two techniques in 71 patients (aged between 52 and 68 years) with symptomatic AF and low left ventricular ejection fraction (40% or lower). They found that PVI resulted in better quality of life, improved physical condition, and higher ejection fractions long-term. AV node ablation, on the other hand, was associated with AF progression and greater use of antiarrhythmic drugs. NOTE: AV node ablation also requires life-long anticoagulation.
• Hsieh, et al. (2005) compared AV node ablation with PVI in a small study of 71 elderly patients with symptomatic AF who could not be successfully treated with antiarrhythmics. Freedom from symptomatic AF was reported in 100% of the AV node ablation patients as compared to 81% in the catheter ablation (PVI) group. However, AV node ablation patients had a significantly greater incidence of heart failure (53% vs 24%), a worsening in left ventricular ejection fraction, and greater progression to persistent AF after 4 years (69% vs 8%).

The Houston researchers conclude that catheter ablation is safe and effective in elderly patients with atrial fibrillation.
Rojas, F and Valderrabano, M. Effect of age on outcomes of catheter ablation of atrial fibrillation. Journal of Atrial Fibrillation, Vol. 6, No.1, June-July 2013, pp. 25-29

Editor's comment: This study confirms that catheter ablation (PVI) is equally effective and safe in younger and older patients and will hopefully help remove any existing barriers to the use of catheter ablation in older AF patients.