Ablation Linked to Lower Incidence of Dementia in AFib Patients

New research from an analysis of patients in a Korean health care database suggests patients with atrial fibrillation (AF) who undergo catheter ablation instead of medical therapy were less likely to develop dementia later in life.

While the study does not prove causation, results suggest undergoing catheter ablation could reduce the incidence of dementia by 27% in patients with AF compared to receiving medication alone.

"The proportion of people who developed dementia during the follow-up period was 6.1% in the ablation group and 9.1% in the medical therapy group,” said lead investigator Boyoung Joung, MD, professor of cardiology and internal medicine at Yonsei University College of Medicine, in a statement. “This suggests that 3 people per 100 of the atrial fibrillation population avoid dementia if they undergo catheter ablation, and 34 patients would need to be treated to prevent one case of dementia during the follow-up period."

After previously publishing research establishing a link between AF and increased risk of dementia, Joung and a team of colleagues sought to further investigate specific associations related to AF treatment and dementia risk. With this in mind, investigators designed their study as an analysis of data from the Korean National Health Insurance Service Database from 2005-2015.

During the 2005-2015 time period, investigators identified 834,735 patients aged 18 years or older diagnosed with AF. From this cohort, investigators identified 194,928 patients who underwent ablation or received medical therapy with antiarrhythmic or rate control drugs. After application of further exclusion criteria, investigators identified a cohort of 9119 patients who underwent ablation and 17,978 patients who received medical therapy alone with a median follow-up of 52 months for inclusion in their analysis.

Of note, investigators excluded patients if they had valvular AF, underwent arrhythmia surgery, used a pacemaker or ICD, had dementia at baseline, or experienced a heart failure admission. For the purpose of analysis, the time-at-risk was calculated from the first medical therapy and ablation was used as a time-varying exposure. Additionally, investigators used propensity score-matching to correct for differences between the study groups.

During the follow-up period, patients who underwent ablation had a lower incidence and risk of overall dementia when compared to their counterparts in the medical therapy arm with rates of 5.6 and 8.1 per 1000 person-years, respectively. After full adjustment for clinical variables and competing risk of mortality, patients undergoing ablations had a 27% lower risk of dementia than those receiving medical therapy alone (HR, 0.73; 95% CI, 0.58-0.93; P <.001).

Investigators pointed out further analysis indicated lower dementia risk was more prominent among patients with ablation success when compared to the overall cohort and these associations were not observed in those with ablation failure.

In an additional analysis assessing risk of Alzheimer’s disease and vascular dementia among these patient groups, investigators found ablation was associated with a lower incidence of both Alzheimer’s disease (HR, 0.77; 95% CI, 0.61-0.97; P=.030) and vascular dementia (HR, 0.50; 95% CI, 0.33-0.74; P <.001) when compared against medical therapy alone. Investigators noted the association between ablation and vascular dementia remained significant after censoring for incident stroke, while the association with a lower risk of Alzheimer’s disease remained consistent but became non-significant.

“We believe the finding that only successful ablation is associated with lower dementia risk is important because it suggests there might be a dose-response relationship between ablation maintaining a regular heart rhythm and a lower risk,” said study investigator Daehoon Kim, a fellow of cardiology at Yonsei University College of Medicine, in the aforementioned statement.

This study, “Less dementia after catheter ablation for atrial fibrillation: a nationwide cohort study,” was published in the European Heart Journal.