No Long-term Decline in Cognitive Performance After TAVR

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Although a number of studies have reported the presence of silent cerebral emboli in patients following transcatheter aortic valve replacement (TAVR), these events appear to have no effect on long-term cognitive functioning, according to findings published online October 15, 2013, ahead of print in Circulation: Cardiovascular Interventions.

Researchers led by Alexander Ghanem, MD, PhD, of University of Bonn (Bonn, Germany), studied 111 TAVR patients, assessing cognitive performance preprocedure and at 3 days, 3 months, 1 year, and 2 years after TAVR. The repeatable battery for the assessment of neuropsychological status (RBANS) was used among other exams.

All patients demonstrated normal focal neurological function prior to TAVR. Outside of 1 ischemic stroke that occurred 8 months after TAVR, there were no cerebrovascular events during follow-up, and normal focal neurological function was demonstrated at each follow-up time point. Overall mortality was 31.5% during follow-up.

Prior to TAVR, cognitive performance was low on average (mean RBANS total score of 82.9). Cognitive decline was indicated in only 6 patients (5.4%) at 3 days postprocedure (RBANS score of 60.0; P < 0.001). Patients experiencing early postprocedural cognitive decline revealed similar preprocedural cognitive performance. In 3 patients (2.7%), early cognitive decline persisted during follow-up. Late onset of cognitive decline was found in 4 patients (3.6%).

Majority Show No Cognitive Decline

The domain affected most frequently was visual and constructional skills. Patients with cognitive decline further experienced significant deficits in language and attention as well as in delayed and immediate memory. The close association between RBANS scores before and after TAVR indicate a stable trajectory of cognitive performance independent of baseline level. None of the 105 patients without early cognitive decline (94.6%) demonstrated significant decline in more than 1 of the 5 neurocognitive domains tested during follow-up. Cognitive decline was a rare event at all time points during follow-up, while cognitive performance remained stable. In all, significant cognitive decline through the first 2 years after TAVR was ruled out in the majority of patients (91%).

Those requiring hemodialysis were more likely to experience cognitive decline 3 days after TAVR (50% vs. 5%; P = 0.009), as were patients who required longer procedure times (123 min vs. 85 min; P = 0.03).

Bleeding events were not associated with cognitive decline, although there seemed to be a slight association with systemic inflammatory response syndrome. Patients with mild cognitive impairment before TAVR experienced no further deterioration over follow-up.

Age, Not Emboli, Associated with Worse Cognitive Function

Fifty-six patients received diffusion-weighted MRI to detect cerebral embolization, which was found in 36 patients (64%) with a median total volume of 0.7 mL. Cerebral embolization was ruled out, meanwhile, in a subset of 20 patients. Interestingly, the subgroup without any embolic events presented comparable cognitive trajectory compared with patients with embolization. Patient age was found to be the only factor significantly associated with longitudinal decline of RBANS total score during follow-up (P = 0.012). In addition, 20 patients (18%) received cerebral embolic protection with the Montage device (Claret Medical, Santa Rosa, CA), but such protection was not associated with early cognitive deficits (P = 1.00).

“Long-term cognitive performance was preserved in the great majority . . . of patients throughout the first 2 years after [TAVR], despite the high intrinsic risk for cognitive deterioration,” the authors conclude. “Taken together, the long-term cognitive trajectory in most patients undergoing [TAVR] is neither influenced by the patient nor by procedural characteristics.”

Josep Rodés-Cabau, MD, of Laval University (Quebec City, Canada), cautioned that the neurocognitive tests used in the study may not be completely validated in the population being assessed. “How sensitive are these cognitive exams in this type of population? We really don’t know,” he told TCTMD in a telephone interview. “I don’t think we know at this time what would be the best method that should be used in this population of TAVI patients, who are very old and have a lot of comorbidities.”

Findings Reflect Clinical Practice

Nevertheless, the results are welcome in an area Dr. Rodés-Cabau called “controversial.”

“I think the results seem to demonstrate that despite the fact that we have a lot of cerebral emboli, it doesn’t seem to be associated with major cognitive impairment,” he added. “This is reassuring.”

Moreover, the findings fit with what is normally seen in clinical practice, Dr. Rodés-Cabau observed. “When we are talking about clinical findings, we follow all our patients in the TAVI clinic and we don’t have the impression that they deteriorate in terms of cognitive status. This is our clinical impression,” he said. “With this single study I don’t think we can conclude that there’s no problem at all, but at least we don’t see anything catastrophic. Again, that fits with our clinical practice.”

Dr. Rodés-Cabau added that detecting minor cognitive deterioration as the study authors attempted to do can be quite difficult. “You need to really be very meticulous in applying these kind of specific tests,” he said, “because these are old patients and I’m not sure it’s so easy to detect.”

 

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Source:
Ghanem A, Kocurek J, Sinning J-M, et al. Cognitive trajectory after transcatheter aortic valve implantation. Circulation: Cardiovasc Intervent. 2013;Epub ahead of print.

 

 

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