Age‐related cardiovascular disease in Down syndrome: A population‐based matched cohort study

Abstract Background Life expectancy for individuals with Down syndrome (DS) has increased dramatically. To improve detection and prevention, the risk of age‐related cardiovascular disease in this population needs to be better defined. Methods We performed a population‐based matched cohort study. Through the National Patient Register (NPR) and/or the Medical Birth Register, we identified all individuals born in Sweden between 1946 and 2000 with a diagnosis of DS. Each individual with DS was matched to 50 comparators by sex, birth year, and county of birth. Data on ischemic and hemorrhagic stroke, acute myocardial infarction (AMI), and covariates indicating cardiovascular risk were retrieved from the NPR. Associations between DS and cardiovascular outcomes were estimated using Cox proportional hazards models. We also assessed the influence of cardiovascular risk factors. Results We included 5155 individuals with DS, of which 55% were male. The median age at the end of follow‐up was 35 in the DS population and 42 among the comparisons. DS was associated with increased risk of ischemic stroke (hazard ratios [HR] 4.41, 95% confidence intervals [CI] 3.53–5.52) and hemorrhagic stroke (HR 5.14, 95% CI 3.84–6.89). The overall risk of AMI was similar in DS and comparators but increased in young individuals with DS. The risk of ischemic stroke was elevated in individuals with DS with selected atherosclerotic (HR 12.67, 95% CI 7.04–22.78) as well as embolic (HR 10.35, 95% CI 6.69–16.01) risk factors, as compared to comparators without risk factors. Conclusion Individuals with DS were at increased risk of cardiovascular outcomes.