Increasing the time between catheter ablation and a diagnosis of atrial fibrillation (AF) is associated with worse outcomes for patients both with or without co-existing heart failure, according to an analysis by US researchers.
AF is the most clinically significant arrhythmia in practice, affecting between 1 and 3% of the population although this rises to 17% in those 80 years of age and older. AF can often co-exist with heart failure and the presence of both conditions, exerts a major detrimental effect on patient’s cardiovascular health and overall wellbeing. While AF can be managed medically with anti-arrhythmic drugs, catheter ablation can also be used and in some cases appears a better option. In fact, a recent study showed that among AF patients with stable heart failure, the use of catheter ablation was superior, with respect to survival, freedom from AF recurrence and quality of when compared to drug treatment. With clearly beneficial effects from ablation therapy, one unanswered question is when the ablation should be undertaken in relation to the AF diagnosis. In other words, might delaying catheter ablation, affect the subsequent risk of death or other outcomes such as hospitalisation for heart failure. In a 2013 study, researchers found that delaying ablation worsened the success of the procedure. Moreover, does the impact of any delay affect patients with differing levels of heart failure, based on the extent of left ventricular dysfunction? This was the subject of the current study by the US team.
Researchers studied patients with at least 12 months follow-up data following their ablation procedure and who were then stratified based on their ejection fraction as either < 35% or > 35%. The team then compared several adverse outcomes such as mortality, heart failure (HF) hospitalisation and AF recurrence in relation to the delay between the initial AF diagnosis and the time of ablation. These delays were categorised as 30 – 180 days, 181 – 454 days, 546 – 1825 days or > 1825 days.
Catheter ablation delay and adverse outcomes
Data were available for 9979 patients with the overall time delay between diagnosis and the first ablation being a median of 2 years and this figure was not significantly different between the two categories of ejection fraction (p = 0.66).
When considering patients with an ejection fraction > 35%, a delay of 181 – 545 days (compared to 30 – 180 days) was associated with a significantly higher mortality risk (hazard ratio, HR = 2.02 (95% CI 1.38 – 2.96) and this risk was more than double, among those waiting longer than 1825 days (HR = 4.39). In addition, there were elevated risks for HF hospitalisations and AF recurrence incurred by delaying ablation therapy.
Among those with an ejection fraction < 35%, there were also elevated risks of mortality, HF hospitalisation and AF recurrence associated with ablation delays, e.g. HR = 3.77 for mortality.
The authors concluded that catheter ablation delays among those with AF increased the risks for adverse events in patients either with or without structural heart disease, highlighting the need for earlier ablation therapy.
Sessions AJ et al. Increasing time between first diagnosis of atrial fibrillation and catheter ablation adversely affects long-term outcomes in patients with and without structural heart disease. J Cardiovasc Electrophysiol 2023