Objective:
We investigated two hypotheses: First, incident CHD, defined as myocardial infarction or definite angina, leads to faster long-term cognitive decline. Second, among those with CHD, treatment with CABG surgery or PCI leads to slower long-term cognitive decline.
Methods:
The Cardiovascular Health Study is a cohort of US adults aged 65+. Global cognitive ability was assessed annually up to 9 times from 1990 to 1998 with the 100-point Modified Mini-Mental State Examination (3MS). We estimated trajectories of 3MS scores in the absence of stroke, adjusting for demographics, health behaviors, and comorbidities. For hypothesis 1, we compared 3MS trajectory after incident CHD with 3MS trajectory in the absence of CHD, censoring at first receipt of CABG/PCI. For hypothesis 2, among participants with CHD, we compared 3MS trajectory after first receipt of CABG/PCI with 3MS trajectory without CABG/PCI.
Results:
For hypothesis 1, of 4,122 participants, 398 had incident CHD during a mean of 5.9 years of follow-up.
Figure Panel A
shows model-predicted mean 3MS trajectories without CHD (blue) and after incident CHD (red) diagnosed at ages 70, 75, 80, or 85. Model-predicted 3MS score declined faster after incident CHD, especially for CHD diagnosed at age 80 or later. For example, after incident CHD at age 85, predicted 5-year decline in mean 3MS score through age 90 was 13.9 points (95% CI: 11.0, 16.7) versus 8.9 points (95% CI: 8.1, 9.7) among those without CHD. For hypothesis 2, of 1,183 participants who had prevalent or incident CHD, 118 had their first CABG/PCI during a mean of 4.1 years of follow-up. Model-predicted 3MS score declined faster after first receipt of CABG/PCI (
Figure Panel B
).
Conclusions:
Older adults diagnosed with incident CHD had faster average cognitive decline than those without CHD. However, treatment with CABG/PCI did not slow cognitive decline among those with CHD. This finding may be due to adverse effects of CABG/PCI on brain health or CABG/PCI recipients having more severe CHD or more cerebral atherosclerosis.
Risk of dementia and death in the long-term follow-up of the Pittsburgh Cardiovascular Health Study-Cognition Study