The risk of vascular dementia, but not Alzheimer’s disease, is higher in post-MI patients
Higher Risk of Vascular Dementia in Myocardial Infarction SurvivorsLiterature - Sundbøll J, Horváth-Puhó E, Adelborg K, et al. - Circulation 2017; published online ahead of print
- 314,911 patients with a first-time MI were followed-up for a median of 7.7 years (25th–75th percentile: 4.0–13.1 years), and 1,573,193 matched individuals from the general population were followed-up for a median of 9.8 years (25th–75th percentile: 5.2–16.0 years).
- Over 35 years of follow-up, the cumulative incidence of all-cause dementia in the MI cohort was 8.7% (2.8% for Alzheimer’s disease, 1.6% for vascular dementia, and 4.5% for other dementias).
- There was no association with all-cause dementia (adjusted HR: 1.01; 95% CI: 0.98–1.03) or non-vascular dementia (adjusted HR: 0.98; 95% CI: 0.95–1.01) compared with the general population cohort.
- The risk was somewhat lower for Alzheimer’s disease (adjusted HR: 0.92; 95% CI: 0.88–0.95), whereas the risk of vascular dementia was significantly higher in the MI cohort (adjusted HR: 1.35; 95% CI: 1.28–1.43).
- The incremental risk of vascular dementia was higher in patients who experienced a stroke within 1 year of MI (adjusted HR: 4.48; 95% CI: 3.29–6.12), and atrial fibrillation or flutter were associated with only moderately higher risk (adjusted HR: 1.55; 95% CI: 1.28–1.87).
- The risk of vascular dementia was also higher in patients who underwent pacemaker implantation (adjusted HR: 3.38; 95% CI: 1.42–8.06) or CABG (adjusted HR: 3.99; 95% CI: 1.31–12.18) during their MI admission.
- The incremental risk of vascular dementia was greater with increasing levels of HF severity, measured by the number of HF hospitalizations during the first year after MI (adjusted HR: 2.24; 95% CI: 1.21–4.14 for ≥3 admissions).
Patients with a history of MI have a higher risk of vascular dementia, particularly if they additionally have a history of stroke. There was no association between MI and Alzheimer’s disease or non-vascular dementia. Common risk factors for MI and vascular dementia may be the driving mechanisms explaining the association between the two diseases. Stroke was a strong modifier of this association, without a substantial impact on the association with other dementia subtypes. These data suggest that strategies for the prevention of vascular dementia in post-MI patients are warranted.