Cognitive outcomes following coronary artery bypass grafting: A systematic review and meta-analysis of 91,829 patients.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of 215 observational studies
PubMed 31078353 · doi:10.1016/j.ijcard.2019.04.065
What was done
A systematic search across four databases identified 215 studies covering 91,829 patients undergoing coronary artery bypass grafting (CABG). Random-effects meta-analyses were conducted to estimate pooled prevalence rates of cognitive impairment, delirium, and dementia across pre-surgical and multiple post-surgical time intervals.
What was found
Pre-surgical cognitive impairment was present in 19% of patients. Acutely post-CABG, cognitive impairment rose to approximately 43%, resolved back to baseline levels (19%) at 4-6 months, increased to 25% between 6 months and 1 year, and reached nearly 40% at 1-5 years post-operatively. Post-operative delirium occurred in 18% of patients overall, increasing to 24% when a structured diagnostic instrument was used alongside clinical criteria. Long-term dementia was reported in 7% of patients at 5-7 years post-surgery.
Why it matters
This review establishes pooled trajectory estimates for post-CABG cognitive decline, showing an acute spike, medium-term recovery, and progressive late deterioration. It underscores the necessity of routine pre- and post-operative cognitive testing and delirium screening.
Limits
The abstract does not report confidence intervals, between-study heterogeneity metrics, or specific diagnostic criteria used across original studies for cognitive impairment. The observational nature of the included literature precludes isolating CABG-specific mechanisms from underlying baseline cardiovascular disease progression, age-related decline, or general surgical effects.
Cited by
- supports Undergoing coronary artery bypass surgery increases the risk of cognitive impairment and Alzheimer's disease.