Investigators randomly assigned 100 patients with symptomatic AFib who had failed at least one anti-arrhythmic drug (AAD) to ongoing therapy or to AFib 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 with no patients in the medical arm.
The study was published online in the July issue of JACC: Clinical Electrophysiology.
Previous research has shown that AFib is associated with cognitive dysfunction independently of stroke, “suggesting that AFib is an additional risk factor for cognitive impairment,” the authors write.
Catheter ablation is an “important pillar” in the management of patients with AFib 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 asigned 100 patients with symptomatic paroxysmal or persistent AFib who had failed greater than or equal to 1 AAD to receive either medical management or catheter ablation. The mean age of the patients was 59 plus or minus 12 years, 32% were women, and 46% had persistent AFib.
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 AFib 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; AFib recurrence and AFib function during follow-up; AAD use during follow-up; and changes to AFib 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 AFib 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, versus 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 with 2% in the medical arm (P = .60). And by 12 months, there were no patients with detectable cognitive dysfunction in the ablation arm, compared with 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 AFib 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 AFib recurrence rates (29% vs. 48%; P = .30). However, both groups were found to have a low AFib burden over the 12 months. And the use of AADs at the 12-month mark was significantly lower among those with versus 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 AFib-related symptoms, compared with those in the medical arm (for both, P < .001).
“Among a contemporary cohort of symptomatic paroxysmal and persistent AFib 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 AFib ablation may prevent the longer-term neurocognitive decline and dementia development associated with AFib.”