Catheter ablation delays worsen outcomes for patients with atrial fibrillation

3rd February 2023

Catheter ablation delays for atrial fibrillation leads to a worsening of adverse cardiac outcomes in patients with and without heart failure

Delaying the use of catheter ablation for those with atrial fibrillation (AF) and or heart heart failure, leads to worse cardiovascular outcomes such as mortality, stroke and AF recurrence according to an analysis by US researchers.

AF is the most clinically significant arrhythmia in practice, affecting between 1 and 3% of the population though this rises to 17% in those 80 years of age and older. AF often co-exists with heart failure and the presence of both conditions, exerts a major detrimental effect on patient’s cardiovascular health and overall wellbeing. Atrial fibrillation can be managed medically with anti-arrhythmic drugs although catheter ablation therapy is also an option. However, a recent study has indicated 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 9,979 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.

Citation
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

Acute myocarditis linked to higher 90-day all-cause mortality and adverse cardiac outcomes

1st November 2021

Acute myocarditis is associated with a high 90-day all-cause mortality and adverse cardiac outcomes including arrhythmias and cardiac arrest.

Patients hospitalised with acute myocarditis (MC) are at an increased risk of all-cause mortality, heart failure, arrhythmias and cardiac arrest compared to matched controls, according to research by a group from the Department of Cardiology, Aalborg University Hospital, Denmark. Inflammation of the cardiac muscle or myocardium (myocarditis) is typically seen in infants and teenagers but can occur at any age. Acute MC symptoms include a stabbing pain and or tightness in the chest which may spread across the body, shortness of breath with light exercise, difficulty in breathing at rest and even flu-like symptoms such as a high temperature, tiredness and fatigue. In addition, acute myocarditis has been shown to be a frequent cause of sudden death in men aged 18 to 28 years of age and in high school athletes. Although evidence points to favourable long-term outcomes in adults with myocarditis, the condition does appear to be associated with an increased risk of  cardiovascular and all-cause mortality within 3 months after discharge.

However, there is limited data on the short-term risks of MC, leading the Danish group to retrospectively analysis the outcomes for patients hospitalised with the condition. The researchers turned to the Danish Civil Registration System, which contains information on all registered Danish citizens and can be linked to other administrative databases. Patients were included in the analysis if they had been hospitalised with a primary diagnosis of MC between 2002 and 2018 or as a secondary diagnosis and with a primary diagnosis of heart failure (HF), ventricular tachycardia (VT), ventricular fibrillation (VF), cardiac arrest and cardioverter-defbrillator (ICD). These secondary diagnoses were used because the clinical diagnosis of MC may involve one of these other conditions. Those with myocarditis was age and sex-matched to a population of control patients without a diagnosis of prior MC in a 1:5 ratio. The primary outcome of interest was 90-day all-cause mortality and secondary outcomes were included 90-day presumed cardiovascular causes of death and 90-day risks for HF, a composite of VT or VF or cardiac arrest and ICD. The analysis involved regression modelling with hazard ratios adjusted for age, sex and co-morbidities.

Findings

A total of 15,138 patients were included in the analysis with 2523 with myocarditis who had a median age of 48 years (67.7% male). The 90-day all-cause mortality risk was 4.9% for those with myocarditis versus 0.3% for controls (p < 0.001), with an adjusted hazard ratio, aHR of 22.12 (95% CI 14.44 – 33.88). Similarly, the 90-day risk for  HF was 75 times higher (aHR = 75.29, 95% CI 42.54 – 133.23, p < 0.001), as was the risk for the VT/VF composite (aHR = 78.80, p < 0.01) and for ICD implantation (aHR = 65.56, p < 0.01).

Commenting on these results, the authors suggested the myocarditis is a serious disease that is associated with a significantly elevated short-term risk of death. They concluded that “patients with acute myocarditis may benefit from careful diagnostic work-up including cardiac monitoring in the early phase after diagnosis.”

Citation