Editorial to “Improvement in quality of life and cardiac function after catheter ablation for asymptomatic persistent atrial fibrillation”

Abstract

Apart from prevention of stroke and thromboembolism, symptom amelioration is the most important management aspect of atrial fibrillation (AF).1 AF is often detected incidentally and clinical AF burden comprises a large percent of asymptomatic episodes. However, asymptomatic AF carries the same thromboembolic risk, and increases the risk of future heart failure, and impairs quality of life and cognitive performance. Progression of AF from paroxysmal to persistent (and permanent) is associated with irreversible pathophysiological changes, making restoring, and maintaining sinus rhythm more difficult. The apparent lack of symptoms may be because of patient adjustment and perception, slow AF rate, early phase of AF, minimal underlying structural heart disease, and low AF burden, or a combination of these. The CABANA trial2 showed that compared to medical therapy, catheter ablation for symptomatic AF improved the quality of life and a Mayo AF-specific symptom score. In a population with 57% in persistent AF, catheter ablation was also superior in preventing AF recurrence (24.7% vs 35.0%). It is difficult to improve symptoms of patients who are apparently “asymptomatic”. The requirements include: (1) appropriate selection of patients who are likely to respond favorably to the strategy of restoring and maintaining sinus rhythm (2) lack of significant comorbidities that may affect AF symptom perception (3) an ablation service with low complications and yet both effective and durable in maintaining sinus rhythmand (4) a sensitive tool to detect differences in symptoms after ablation. In this issue of the Journal, Onishi 3 have explored the use of catheter ablation in a single center, retrospective cohort study to address some of these confounding variables. In 45 patients with asymptomatic persistent AF detected incidentally, they showed that AF ablation improved symptom frequency, activity limits, and mental anxiety after catheter ablation using a validated disease-specific AF quality of life measure for Japanese patients. While symptom severity was not affected, there was a beneficial impact on atrial size and left ventricular function and plasma brain-type natriuretic peptide level after 3 months. These changes were durable over 5 years. Their patient group has a mean age of 62.9 ± 8.6 years and most have persistent AF <1 year (71.1%), and only borderline increase in left atrial size and comorbidities as defined by a CHADS2 score of 1. The quality of their AF ablation was very high, with zero acute complication, and 85.7% of patients remaining in sinus rhythm up to 5 years (with 24% of patients agreed for a repeat ablation). These results compared favorably with the generally accepted results for catheter ablation success1 Importantly, no patients developed permanent AF. Catheter AF ablation is a class I indication for symptomatic patients refractory to at least one oral antiarrhythmic drug, and a class IIa for those without prior drug failure1 It may be considered in asymptomatic patients with depressed left ventricular function. The role of ablation for asymptomatic patient found incidentally and with normal left ventricular function is unknown. However, in patients with paroxysmal AF, AF ablation success remains high. But development into permanent or long-term persistent AF is associated with a lower success rate, so delaying ablation may be a missed opportunity. An observation not sufficiently discussed in Onishi et al s article3 was the prevention of AF progression. In the RECORD AF study4 among 5171 patients with the majority presenting with recent onset non-permanent AF, progression to permanent AF occurred in 31% of patients by the second visit (13% assigned to rhythm control vs 54% to rate control). Risk factors for AF progression include initial persistent AF, duration of AF > 3 months, heart failure, and age > 75 years and when only rate control was used. AF progression is associated with increased risk of heart failure and adverse cardiovascular outcomes.5 It is remarkable that in this cohort of patients with persistent AF > 3 months, RF ablation resulted in no patients progressing to permanent AF over a period of 5 years. This suggests that early effective AF intervention promotes reverse remodeling and avoids heart failure. A recent randomized trial6 revisited the strategy for patients with recently discovered AF (<1 year). In 2789 patients in European centers, early initiation of rhythm control strategy (predominantly medical, with AF ablation in 8% by 1 year) was associated with a reduction of primary adverse cardiovascular endpoint versus usual rate control care (3.9 vs 5.0 per 100 person-year). There was no significant increase in hospital stay nor safety concerns in the rhythm control strategy arm. Notably, a majority of the patients had no or minimal AF symptoms as assessed by European Heart Rhythm Association score, and rhythm control therapy was started within a mean of 36 days. The present study gives support for early rhythm control by catheter ablation for incidentally identified asymptomatic AF. As the authors have pointed out, this is a small retrospective single-center study. Additional limitations include the percentage