Among patients with atrial fibrillation, the risk for dementia is lowered after successful catheter ablation, a new study suggests. Medical records from nearly 27,000 patients with atrial fibrillation show that those who were successfully treated with ablation were 44% less likely to develop dementia than patients who received medical therapy, researchers reported in the European Heart Journal. "We found that successful ablation significantly reduced dementia by 44% compared with medical therapy but if ablation failed we did not see a significant reduction in risk, said Dr. Daehoon Kim, a clinical fellow in the division of cardiology at Yonsei University College of Medicine in Seoul, Korea. "This suggests that it is maintaining the regular rhythm of the heart with successful ablation, and not ablation itself, that may contribute to the lower risk of dementia in patients with atrial fibrillation and provides evidence to assist clinicians in pursuing sinus rhythm in AF patients," Dr. Kim said in an email. An earlier study by the same group of researchers showed that atrial fibrillation was linked to an increased risk of dementia, even in patients who had not suffered a stroke. To explore the possibility that ablation might improve the odds of not getting dementia, Dr. Kim and his colleagues turned to a national health claims database established by the National Health Insurance Service of Korea, which covers a population of 51.5 million. The database included a total of 834,735 patients diagnosed with atrial fibrillation between 2005 and 2015. Included in the researchers' analysis were 9,119 patients who received ablation and 17,978 who received medical therapy. During a median follow-up of 52 months (IQR 29, 86), the incidence rate of dementia was 5.6 per 1,000 person-years in the ablation group and 8.1 per 1,000 person-years in the medical therapy group. The researchers estimate that 34 patients would need to be treated with ablation to prevent one case of dementia during the follow-up period. Overall, ablation reduced the risk of dementia by 27%. But when the researchers focused on patients who had successful ablations—those who did not require repeat ablations, cardioversion or medical therapy—the odds were even better with a 44% reduced risk of dementia compared with medical therapy. One major limitation of the study is that it was observational, the researchers noted. The new study is "very intriguing," said Dr. Sandeep Jain, a professor of medicine at the University of Pittsburgh School of Medicine and director of electrophysiology and director of the Center for Atrial Fibrillation at the UPMC Center for Heart and Vascular Institute. "There's clearly evidence of cognitive decline in patients with atrial fibrillation over time," Dr. Jain said. "That's been shown in lots of studies in the past." And there have been hints that restoring sinus rhythm might help reduce the risk of cognitive decline, Dr. Jain said. "This study adds to that body of evidence," he added. "Does it change our practice today, meaning we would do catheter ablation to decrease the risk of dementia? I don't think this study provides that level of evidence." It does suggest that more studies need to be done, Dr. Jain said. "We need more data," he added. —Linda Carroll Source
