Preoperative daily step count and cognitive performance following cardiac surgery

Postoperative neurocognitive disorders impact 40 to 50% of patients after cardiac surgery. In older adults, walking more than 6500 steps per day is associated with cognitive benefits. The purpose of this study was to determine if walking 6500 steps or more per day before surgery was associated with less postoperative neurocognitive disorder.

This single-center, observational, pilot study enrolled patients aged 60 years or more undergoing elective cardiac surgery. Daily step counts were recorded continuously for at least 5 full days before surgery and for 90 days after surgery. Montreal Cognitive Assessment was administered (1) at enrollment, (2) at discharge, (3) on postoperative day 30, and (4) on postoperative day 90. Patients were stratified into low steps (<6500 steps/day) or high steps (≥6500 steps/day) based on their preoperative average daily step count. Postoperative cognitive decline was defined as 1 or more SD decline in Montreal Cognitive Assessment score from baseline.

A total of 44 patients were enrolled, and 39 patients completed the study. Patients' average age was 67 years, 41.7% were female, and 61.5% were in the low steps cohort. Median preoperative step counts in patients with low steps versus high steps were 5002 versus 9140 (P < .01). Patients with low steps were more likely female (P < .01) and had longer time to extubation, lower nadir hemoglobin levels, more postoperative cognitive decline at discharge (41.7% vs 6.7%, P = .03), and lower Montreal Cognitive Assessment scores at discharge. Multivariable logistic regression showed high step counts were independently associated with lower odds of cognitive decline (odds ratio, 0.104, 95% CI, 0.007-0.776, P = .03).

Walking 6500 steps or more per day before surgery predicts better postoperative cognitive performance.