Cognitive risk with common heart procedures may be small

By Megan Brooks

NEW YORK (Reuters Health) - A decline in cognitive function after common invasive heart procedures may not be inevitable for older adults.

On the contrary, cognitive decline following coronary and carotid revascularization, cardiac valve procedures, and catheter ablation for atrial fibrillation (AF) may be uncommon, according to a systematic literature review published online July 20 in Annals of Internal Medicine.

The researchers caution, however, that the strength of evidence is "mostly low to insufficient," and they advise doctors to tell patients about the "uncertainty" in their risk for cognitive difficulties after surgery.

Each year in the U.S., patients age 65 and older undergo roughly 200,000 coronary artery bypass graft (CABG) surgeries, 50,000 carotid revascularizations, 50,000 cardiac valve replacements or repairs, and 10,000 catheter ablations for AF, Dr. Howard Fink of the Veterans Affairs Health Care System in Minneapolis, Minnesota, and colleagues note in their paper. The risk of intermediate and long-term cognitive decline after these procedures is "poorly understood."

To investigate, they did a systematic review of 17 trials and four cohort studies. Participants were mostly male (80%) with a mean age of 68 years.

Cognition did not differ after the procedure in trials comparing on- or off-pump CABG, hypothermic and normothermic CABG, or CABG and medical management, although the strength of evidence was low. One trial noted a lower risk for cognitive impairment with minimal versus conventional extracorporeal CABG, but again with a low strength of evidence.

Two trials suggested no difference between surgical carotid revascularization and carotid stenting or angioplasty (with low and insufficient strength of evidence, respectively). One cohort study found increased cognitive decline after transcatheter versus surgical aortic valve replacement but this study had issues with selection and outcome measurement biases (insufficient strength of evidence).

In email to Reuters Health, Dr. Fink said these findings "may be reassuring to clinicians and patients."

"Anecdotally, it seemed there still was this impression that these procedures can commonly cause cognitive impairment. It isn't unusual for a patient/family member presenting to our Memory Loss Clinic to attribute onset of cognitive impairment to a cardiovascular procedure. The evidence we found mostly didn't support that," Dr. Fink said.

"However, several caveats must be attached to these statements, including that we found no data from eligible studies of atrial fibrillation ablation and little data on cardiac valve procedures, that strength of evidence was mostly low to insufficient, and that generalizability of these findings to the oldest old, women, and patients with substantial pre-procedure cognitive impairment is uncertain."

The study was supported by the Agency for Healthcare Research and Quality, which provided individual support to four researchers during the study.

SOURCE: http://bit.ly/1CSyxXv

Ann Intern Med 2015.

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