A population-based matched cohort study from Sweden found that adults with Down syndrome had a significantly higher risk of both ischemic and hemorrhagic stroke compared with the general population, particularly among younger individuals.
These findings underscore the importance of early cardiovascular risk assessment and targeted prevention strategies in this population.
The overall risk of acute myocardial infarction (AMI) was not significantly different between groups (hazard ratio [HR], 0.85; 95% confidence interval [CI], 0.56–1.29). However, among adults younger than 40 years, the risk of AMI was significantly elevated in those with Down syndrome (HR, 3.48; 95% CI, 1.55–7.78), suggesting an earlier onset of cardiovascular disease.
Researchers analyzed national health records from more than 260,000 individuals born between 1946 and 2000, including 5,155 adults with a confirmed diagnosis of Down syndrome. Each case was matched with 50 controls by sex, birth year, and county of birth. Cardiovascular outcomes—including ischemic stroke, hemorrhagic stroke, and AMI—were tracked through 2018 using validated national health registries and standard diagnostic codes.
Adults with Down syndrome were more than four times as likely to experience ischemic stroke (HR, 4.41; 95% CI, 3.53–5.52) and more than five times as likely to experience hemorrhagic stroke (HR, 5.14; 95% CI, 3.84–6.89), regardless of sex or presence of traditional cardiovascular risk factors such as diabetes or congenital heart disease.
The presence of embolic risk factors—defined in this study as congenital heart malformations or arrhythmias—further increased risk. Adults with Down syndrome and embolic risk factors had more than ten times the risk of ischemic stroke (HR, 10.35; 95% CI, 6.69–16.01) compared with controls without such risk factors.
Heart malformations were identified in approximately 30% of adults with Down syndrome, versus just 0.7% of controls. Diabetes was also more prevalent in the Down syndrome group (5.3% vs 3.3%).
Despite comparable overall risk of AMI, individuals with Down syndrome were significantly less likely to undergo coronary artery surgery. Only 0.1% of individuals with Down syndrome received a coronary intervention, compared with 1.4% of controls. The study did not assess underlying reasons for this disparity, but potential explanations may include differences in comorbidities, treatment eligibility, or access to care.
These findings contradict the view that individuals with Down syndrome are spared from cardiovascular outcomes due to presumed protection from atherosclerosis. The study instead indicated that cerebrovascular and ischemic heart diseases may arise from different pathophysiologic mechanisms in this population. Although treatment strategies were not assessed, the findings support the importance of early screening and further investigation into the cardiovascular risk profile specific to Down syndrome.
The authors reported no conflicts of interest.
Source: Journal of Internal Medicine