Catheters

Catheter ablation and lower risk of incident dementia and mortality in older adults with atrial fibrillation

Author/s: 
Harrison, Stephanie L., Buckley, Benjamin J.R.

Background: Atrial fibrillation (AF) has consistently been associated with a higher risk of incident dementia. Observational evidence has suggested catheter ablation may be associated with a lower risk of dementia in patients with AF, but further research is needed. The objectives of this study were to use a global health research network to examine associations between catheter ablation, incident dementia and mortality in older adults with AF, and amongst subgroups by age, sex, co-morbidity status, and oral anticoagulant use.

Methods: The research network primarily included healthcare organizations in the United States. This network was searched on 28th September 2022 for patients aged ≥65 years with a diagnosis of AF received at least 5 years prior to the search date. Cox proportional hazard models were run on propensity-score matched cohorts.

Results: After propensity score matching, 20,746 participants (mean age 68 years; 59% male) were included in each cohort with and without catheter ablation. The cohorts were well balanced for age, sex, ethnicity, co-morbidities, and cardiovascular medications received. The risk of dementia was significantly lower in the catheter ablation cohort (Hazard Ratio 0.52, 95% confidence interval: 0.45-0.61). The catheter ablation cohort also had a lower risk of all-cause mortality (Hazard Ratio 0.58, 95% confidence interval: 0.55-0.61). These associations remained in subgroup analyses in individuals aged 65-79 years, ≥80 years, males, females, participants who received OACs during follow-up, participants with paroxysmal and non-paroxysmal AF, and participants with and without hypertension, diabetes mellitus, ischemic stroke, chronic kidney disease and heart failure, including heart failure with preserved ejection fraction and heart failure with reduced ejection fraction.

Conclusion: The observed lower risk of dementia and mortality with catheter ablation could be an important consideration when determining appropriate patient-centered rhythm control strategies for patients with AF. Further studies including data on the success of ablation are required.

Progression of Atrial Fibrillation after Cryoablation or Drug Therapy

Author/s: 
Andrade, J.G., Deyell, M. W., Macle, L., Wells, G. A., Bennett, M., Essebag, V., Champagne, J., Roux, J., Yung, D., Skanes, A., Khaykin, Y., Morillo, C., Jolly, U., Novak, P., Lockwood, E., Cadrin-Tourigny, J., Kochhäuser, S., Verma, A.

Background: Atrial fibrillation is a chronic, progressive disorder, and persistent forms of atrial fibrillation are associated with increased risks of thromboembolism and heart failure. Catheter ablation as initial therapy may modify the pathogenic mechanism of atrial fibrillation and alter progression to persistent atrial fibrillation.

Methods: We report the 3-year follow-up of patients with paroxysmal, untreated atrial fibrillation who were enrolled in a trial in which they had been randomly assigned to undergo initial rhythm-control therapy with cryoballoon ablation or to receive antiarrhythmic drug therapy. All the patients had implantable loop recorders placed at the time of trial entry, and evaluation was conducted by means of downloaded daily recordings and in-person visits every 6 months. Data regarding the first episode of persistent atrial fibrillation (lasting ≥7 days or lasting 48 hours to 7 days but requiring cardioversion for termination), recurrent atrial tachyarrhythmia (defined as atrial fibrillation, flutter, or tachycardia lasting ≥30 seconds), the burden of atrial fibrillation (percentage of time in atrial fibrillation), quality-of-life metrics, health care utilization, and safety were collected.

Results: A total of 303 patients were enrolled, with 154 patients assigned to undergo initial rhythm-control therapy with cryoballoon ablation and 149 assigned to receive antiarrhythmic drug therapy. Over 36 months of follow-up, 3 patients (1.9%) in the ablation group had an episode of persistent atrial fibrillation, as compared with 11 patients (7.4%) in the antiarrhythmic drug group (hazard ratio, 0.25; 95% confidence interval [CI], 0.09 to 0.70). Recurrent atrial tachyarrhythmia occurred in 87 patients in the ablation group (56.5%) and in 115 in the antiarrhythmic drug group (77.2%) (hazard ratio, 0.51; 95% CI, 0.38 to 0.67). The median percentage of time in atrial fibrillation was 0.00% (interquartile range, 0.00 to 0.12) in the ablation group and 0.24% (interquartile range, 0.01 to 0.94) in the antiarrhythmic drug group. At 3 years, 8 patients (5.2%) in the ablation group and 25 (16.8%) in the antiarrhythmic drug group had been hospitalized (relative risk, 0.31; 95% CI, 0.14 to 0.66). Serious adverse events occurred in 7 patients (4.5%) in the ablation group and in 15 (10.1%) in the antiarrhythmic drug group.

Conclusions: Initial treatment of paroxysmal atrial fibrillation with catheter cryoballoon ablation was associated with a lower incidence of persistent atrial fibrillation or recurrent atrial tachyarrhythmia over 3 years of follow-up than initial use of antiarrhythmic drugs. (Funded by the Cardiac Arrhythmia Network of Canada and others; EARLY-AF ClinicalTrials.gov number, NCT02825979.).

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