Despite concern that cardiac surgery may adversely affect cognition, little evidence is available from population-based studies using presurgery data. With the use of the Health and Retirement Study, we compared memory change after participant-reported cardiac catheterization or cardiac surgery.
Participants were community-dwelling adults aged 65 years and older who self-reported cardiac catheterization or “heart surgery” at any biennial Health and Retirement Study interview between 2000 and 2014. Participants may have undergone the index procedure any time in the preceding 2 years. We modeled preprocedure to postprocedure change in composite memory score, derived from objective memory testing, using linear mixed effects models. We modeled postprocedure subjective memory decline with logistic regression. To quantify clinical relevance, we used the predicted memory change to estimate impact on ability to manage medications and finances independently.
Of 3,105 participants, 1,921 (62%) underwent catheterization and 1,184 (38%) underwent operation. In adjusted analyses, surgery participants had little difference in preprocedure to postprocedure memory change compared with participants undergoing cardiac catheterization (−0.021 memory units; 95% confidence interval: −0.046 to 0.005 memory units, p = 0.12). If the relationship were causal, the point estimate for memory decline would confer an absolute 0.26% or 0.19% decrease in ability to manage finances or medications, respectively, corresponding to 4.6 additional months of cognitive aging. Cardiac surgery was not associated with subjective memory decline (adjusted odds ratio 0.93, 95% confidence interval: 0.74 to 1.18).
In this large, population-based cohort, memory declines after heart surgery and cardiac catheterization were similar. These findings suggest intermediate-term population-level adverse cognitive effects of cardiac surgery, if any, are likely subtle.