Prior Myocardial Infarction and Cognitive Decline: The REGARDS Cohort

Acute myocardial infarction (MI) is associated with subsequent cognitive decline. Whether the detection of prior MI using routine ECG and self-reported history can identify different trajectories of cognitive decline is uncertain. We sought to determine the association between prior MI and longitudinal cognitive assessments within a national, biracial cohort study.

We included participants in the REGARDS (Reasons for Geographic and Racial Differences in Stroke) cohort, enrolled from 2003 to 2007, who had an interpretable ECG and no baseline cognitive impairment. Prior MI at baseline was determined by self-reported history and ECG evidence of MI. Individuals were subdivided into self-reported (no Q-wave with MI history), clinical (Q-wave with MI history), and silent MI (Q-wave without MI history). We examined the interaction between prior MI and longitudinal change in global cognitive function, assessed by annual telephone-based 6-item screener scores, using linear mixed-effects models adjusted for demographics, cardiovascular risk factors, and incident cardiovascular events with censoring for death.

The primary analytic cohort consisted of 20 923 individuals followed over a median of 10.1 years with 2183 having evidence of prior MI at baseline (1098 self-reported, 281 clinical, and 804 silent MI). A total of 4884 participants died during follow-up and were censored at the time of death. Prior MI was associated with an excess adjusted annual decline of global cognition (-0.016 points [95% CI, -0.021 to -0.012]; P_interaction<0.001). Similar trajectories of accelerated annual global cognitive decline were seen with self-reported (-0.016 points [95% CI, -0.022 to -0.010]; P_interaction<0.001), clinical (-0.020 points [95% CI, -0.032 to -0.008]; P_interaction=0.001), and silent (-0.015 points [95% CI, -0.022 to -0.008]; P_interaction<0.001) MI.

Evidence of prior MI, whether clinically recognized or silent, was associated with an accelerated decline in global cognition. Prior MI may identify individuals at risk for future cognitive impairment.