Association of Coronary Artery Bypass Grafting vs Percutaneous Coronary Intervention with Memory Decline in Older Adults Undergoing Coronary Revascularization

Importance: It is uncertain whether coronary artery bypass grafting (CABG) is associated with cognitive decline in older adults compared with a nonsurgical method of coronary revascularization (percutaneous coronary intervention [PCI]). Objective: To compare the change in the rate of memory decline after CABG vs PCI. Design, Setting, and Participants: Retrospective cohort study of community-dwelling participants in the Health and Retirement Study, who underwent CABG or PCI between 1998 and 2015 at age 65 years or older. Data were modeled for up to 5 years preceding and 10 years following revascularization or until death, drop out, or the 2016-2017 interview wave. The date of final follow-up was November 2017. Exposures: CABG (including on and off pump) or PCI, ascertained from Medicare fee-for-service billing records. Main Outcomes and Measures: The primary outcome was a summary measure of cognitive test scores and proxy cognition reports that were performed biennially in the Health and Retirement Study, referred to as memory score, normalized as a z score (ie, mean of 0, SD of 1 in a reference population of adults aged ≥72 years). Memory score was analyzed using multivariable linear mixed-effects models, with a prespecified subgroup analysis of on-pump and off-pump CABG. The minimum clinically important difference was a change of 1 SD of the population-level rate of memory decline (0.048 memory units/y). Results: Of 1680 participants (mean age at procedure, 75 years; 41% female), 665 underwent CABG (168 off pump) and 1015 underwent PCI. In the PCI group, the mean rate of memory decline was 0.064 memory units/y (95% CI, 0.052 to 0.078) before the procedure and 0.060 memory units/y (95% CI, 0.048 to 0.071) after the procedure (within-group change, 0.004 memory units/y [95% CI, -0.010 to 0.018]). In the CABG group, the mean rate of memory decline was 0.049 memory units/y (95% CI, 0.033 to 0.065) before the procedure and 0.059 memory units/y (95% CI, 0.047 to 0.072) after the procedure (within-group change, -0.011 memory units/y [95% CI, -0.029 to 0.008]). The between-group difference-in-differences estimate for memory decline for PCI vs CABG was 0.015 memory units/y (95% CI, -0.008 to 0.038; P =.21). There was statistically significant increase in the rate of memory decline after off-pump CABG compared with after PCI (difference-in-differences: mean increase in the rate of decline of 0.046 memory units/y [95% CI, 0.008 to 0.084] after off-pump CABG), but not after on-pump CABG compared with PCI (difference-in-differences: mean slowing of decline of 0.003 memory units/y [95% CI, -0.024 to 0.031] after on-pump CABG). Conclusions and Relevance: Among older adults undergoing coronary revascularization with CABG or PCI, the type of revascularization procedure was not significantly associated with differences in the change of rate of memory decline.