Long-Term Brain Health Decline Seen Following Incident MI

Short-term brain health—as measured by global cognition, memory, and executive function changes—was preserved in the immediate aftermath of a myocardial infarction (MI), or heart attack, but overall faster declines in brain health were seen for these capabilities over the long term, according to study findings in JAMA Neurology.

“The magnitude of cognitive change after incident MI is unclear,” the study authors wrote. “Dementia is common, costly, highly morbid, and lacking treatments. An understanding of the vascular contributions to cognitive decline could identify potential targets for interventions to slow or prevent dementia.”

Their cohort analysis consolidated 1971-to-2019 data from 6 major cohort investigations: Atherosclerosis Risk in Communities Study, Coronary Artery Risk Development in Young Adults Study, Cardiovascular Health Study, Framingham Offspring Study, Multi-Ethnic Study of Atherosclerosis, and Northern Manhattan Study. The mean (SD) age of the adult (n = 30,465) participants was 64 (10) years, and 56% were female patients. None had a history of MI, stroke, or dementia at baseline.

Over the median (IQR) follow-up of 6.4 (4.9-19.7) years, 3.4% (n = 1033) reported 1 or more MI events and 0.45% (n = 137), 2 MI events. Per their findings, the investigators did not see a relationship between incident MI and acute, or quickly worsening, drops in global cognition, memory, and executive function:

• Global cognition: –0.18 (95% CI, –0.52 to 0.17) points
• Executive function: –0.17 (95% CI, –0.53 to 0.18) points
• Memory: 0.62 (95% CI, –0.07 to 1.31) points

However, the long-term picture was different. On an annual basis, declines were faster after an MI compared with before:

• Global cognition: –0.15 (95% CI, −0.21 to −0.10) points
• Memory: −0.13 (95% CI, −0.22 to −0.04) points
• Executive function: −0.14 (95% CI, −0.20 to −0.08) points

At baseline, the median global cognitive performance scores were equivalent in those with at least 1 MI (52 [47-57]) and no MI (52 [46-57]); memory scores were 50 (46-56) and 51 (46-56), respectively; and executive function scores were 50 (46-56) and 51 (46-57).

According to the study authors, a patient’s race and sex are potential risk factors for post-MI long-term outcomes, with Black vs White patients and female vs male patients experiencing less-severe declines in the long term:

• Black vs White patients: 0.22 (95% CI, 0.04-0.40) points per year
• Female vs male patients: 0.12 (95% CI, 0.01-0.23) points per year

“The interaction analysis suggested that race and sex modified the degree of change in the decline in global cognition after MI (race × post-MI slope interaction term, P = .02; sex × post-MI slope interaction term, P = .04),” they wrote. 

Most participants with at least 1 incident MI and those with none were White (83.7% and 68.6%, respectively) or Black (13.0% and 23.0%), did not drink during the week (52.0% and 56.0% reported 0 drinks), had median cumulative systolic blood pressures of 142 (130-155) and 134 (123-147) mm Hg, and had median low-density lipoprotein cholesterol levels of 135 (112-161) and 123 (100-147) mg/dL.

Additional analyses showed these results:

• Median times between last pre-MI cognitive assessment and incident MI were 1.88 years for global cognition, 2.17 years for executive function, and 3.67 years for memory
• Median times between incident MI and first post-MI assessment were 1.85, 2.21, and 3.71 years, respectively
• Mean cognitive assessments after incident MI were 2.63 (2.23), 2.06 (1.68), and 1.41 (0.68)
• For those reporting a second MI, long-term global functioning did not drop but executive functioning did (−1.55 points annually; 95% CI, −2.63 to −0.48)

The investigators said their findings echo prior research showing a gradual change in cognition after an MI but that an incident MI still accelerates long-term cognition change and that “the lack of a significant cognitive change in the short term in the overall study population suggests that cognitive change is not secondary to acute illness or delirium but rather a sustained impairment in cognition.”

“Our results may have important public health implications. Discussion of the potential cognitive ramifications of MI should be considered as a potential motivator when counseling patients at risk for MI,” they concluded. “Additionally, individuals who have experienced an MI should be followed up for accelerated cognitive decline in the years after MI. The findings also suggest that prevention of MI may be a strategy to preserve brain health in older adults.”

Reference

Johansen MC, Ye W, Gross A, et al. Association between acute myocardial infarction and cognition. JAMA Neurol. Published online May 30, 2023. doi:10.1001/jamaneurol.2023.1331