A new study shows that although postoperative cognitive dysfunction can occur following catheter ablation for atrial fibrillation (AF), it is transient, and patients recover completely within a year.
Investigators randomly assigned 100 patients with symptomatic AF who had failed at least one anti-arrhythmic drug (AAD) to ongoing therapy or to AF catheter ablation. Patients were followed for 1 year, and changes in cognitive performance were assessed at baseline and at 3, 6, and 12 months.
Although patients in the ablation arm initially showed more cognitive dysfunction than those in the medical arm, at 6 months, the gap was smaller; and at 12 months, no patients in the ablation arm showed signs of cognitive dysfunction. In fact, more than 1 in 10 showed signs of cognitive improvement, compared to no patients in the medical arm.
The study was published online in the July issue of JACC: Clinical Electrophysiology.
Previous research has shown that AF is associated with cognitive dysfunction independently of stroke, “suggesting that AF is an additional risk factor for cognitive impairment,” the authors write.
Catheter ablation is an “important pillar” in the management of patients with AF that is refractory to medical therapy, but postoperative cognitive dysfunction (POCD) may occur in the immediate aftermath of the procedure, they note. Little is known about whether these cognitive changes persist long term, and no randomized studies have investigated this issue.
The researchers randomly 100 patients with symptomatic paroxysmal or persistent AF who had failed ≥1 AAD to receive either medical management or catheter ablation. The mean age of the patients was 59 ± 12 years, 32% were women, and 46% had persistent AF.
Medical management consisted of optimization of AADs to maintain sinus rhythm. For those who underwent ablation, AADs were discontinued five half-lives prior to the procedure (with the exception of amiodarone).
Participants were followed for 12 months after enrollment. Clinical reviews and cognitive testing were performed at 3, 5, and 12 months during that time.
AADs and oral anticoagulation were weaned and were discontinued 3 months after the procedure, depending on each patient’s individual risk profile.
Cognitive testing included the Consortium to Establish a Registry for Alzheimer’s Disease (CERAD) Auditory Verbal Learning Test and Semantic Fluency test; the Controlled Oral Word Association test; and the Trail Making Task (parts A and B).
Participants also completed the University of Toronto AF Symptom Severity Scale at baseline and at all follow-up visits.
The primary endpoint was prevalence of new-onset cognitive dysfunction. Main secondary endpoints included improvement in cognitive function during follow-up; AF recurrence and AF function during follow-up; AAD use during follow-up; and changes to AF symptom severity assessment scores during follow-up.
More Research Needed
Of the 100 participants, 96 completed the study protocol (52 in the ablation group and 48 in the medical management group). There were no significant differences between the groups regarding baseline demographics, clinical AF risk factors, and echocardiographic parameters.
At 3 months, new-onset cognitive dysfunction was detected across a wide range of the neuropsychological tests in 14% of participants in the ablation arm, vs 2% of participants in the medical arm (P = .03)
But at 6 months, only 4% of patients in the ablation arm displayed cognitive dysfunction, compared again to 2% in the medical arm (P = .60). And by 12 months, there were no patients with detectable cognitive dysfunction in the ablation arm, compared to the same patient who showed cognitive impairment in the medical arm (P = .30).
Longer ablation time was an independent predictor of new-onset cognitive dysfunction (odds ratio, 1.30; 95% CI, 1.01 – 1.60; P = .003).
When patients with and those without new-onset cognitive dysfunction were compared, no differences were found in arrhythmia recurrence or AF burden post ablation.
At 12 months, 14% of those in the ablation arm showed improvement in cognitive performance, compared with no participants in the medical arm (P = .007).
Compared with participants who had no change in cognitive performance, those who had a significant improvement had a trend toward lower AF recurrence rates (29% vs 48%; P = .30). However, both groups were found to have a low AF burden over the 12 months. And the use of AADs at the 12-month mark was significantly lower among those with vs those without cognitive improvement (0% vs 38%; P = .04).
As early as 3 months post procedure and then at 12 months, participants in the ablation group had significant improvement in AF-related symptoms, compared with those in the medical arm (for both, P < .001).
“Among a contemporary cohort of symptomatic paroxysmal and persistent AF patients, catheter ablation was associated with a transient decline in cognitive function in the short-term, followed by recovery at 12 months,” the authors conclude.
They note that further large studies “are required to determine with AF ablation may prevent the longer-term neurocognitive decline and dementia development associated with AF.”
Commenting for theheart.org | Medscape Cardiology, Andrea Natale, MD, executive medical director, Texas Cardiac Arrhythmia Institute at St. David’s Medical Center, Austin, said POCD is “very likely due to the vulnerable state of mind and the stress that the patients encounter while undergoing the cardiac procedure,” as well as postsurgical inflammation, which “can cause brief functional alterations in the brain, leading to temporary cognitive impairment.” Inadequate preprocedural anticoagulation may also play a role.
Natale, co-author of an accompanying editorial, said it’s “prudent” when evaluating cognitive function to use questionnaires that are “sensitive to mild cognitive impairment,” such as the Montreal Cognitive Assessment or the Mini–Mental State Examination.
Additionally, “post-ablation cognitive function should be assessed way after the blanking period to avoid any plausible impact of inflammation, medications, the feeling of being overwhelmed, and the stress of undergoing a cardiac procedure,” advised Natale, who was not involved with the study.
Also commenting for theheart.org | Medscape Cardiology, Matthew Hyman, MD, PhD, an electrophysiologist and assistant professor of medicine at the Hospital of the University of Pennsylvania, called it a “well-done and very reassuring study.”
Hyman, who was also not part of the research team, added that previous work has shown an association between AF and dementia, “and it remains to be seen if patients with rhythm control over longer durations than the current studies have the best outcomes.”
Al-Kaisey, Parameswaran, Wong, Anderson, Voskoboinik, Chieng, and Sugumar are supported by the National Health and Medical Research Council research scholarship. Kalman is supported by a practitioner fellowship from the National Health and Medical Research Council; has received research support from Biosense Webster, Boston Scientific, Abbott, and Medtronic; and has served on the advisory board of Boston Scientific and Biosense Webster. Natale is a consultant for Abbott, Baylis, Biosense Webster, Biotronik, Boston Scientific, and Medtronic. Hyman is a consultant/speaker for Abbott, Biosense Webster and Boston Scientific.
JACC Clin Electrophysiol. July 2023;9:1024-1034, 1035-1037. Abstract, Editorial
Batya Swift Yasgur, MA, LSW, is a freelance writer with a counseling practice in Teaneck, New Jersey. She is a regular contributor to numerous medical publications, including Medscape and WebMD, and is the author of several consumer-oriented health books as well as Behind the Burqa: Our Lives in Afghanistan and How We Escaped to Freedom (the memoir of two brave Afghan sisters who told her their story).
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