Community-based case-control study of childhood stroke risk associated with congenital heart disease

Background and purpose: A better understanding of the stroke risk factors in children with congenital heart disease (CHD) could inform stroke prevention strategies. We analyzed pediatric stroke associated with CHD in a large community-based case-control study.

Methods: From 2.5 million children (aged <20 years) enrolled in a Northern California integrated healthcare plan, we identified children with ischemic and hemorrhagic strokes and randomly selected age- and facility-matched stroke-free controls (3 per case). We determined exposure to CHD (diagnosed before stroke) and used conditional logistic regression to analyze stroke risk factors.

Results: CHD was identified in 15 of 412 cases (4%) versus 7 of 1236 controls (0.6%). Cases of childhood stroke (occurring between ages 29 days to 20 years) with CHD had 19-fold (odds ratio, 19; 95% confidence interval 4.2-83) increased stroke risk compared to controls. History of CHD surgery was associated with >30-fold (odds ratio, 31; confidence interval 4-241) increased risk of stroke in children with CHD when compared with controls. After excluding perioperative strokes, the history of CHD surgery still increased the childhood stroke risk (odds ratio, 13; confidence interval 1.5-114). The majority of children with stroke and CHD were outpatients at the time of stroke, and almost half the cases who underwent cardiac surgery had their stroke >5 years after the most recent procedure. An estimated 7% of ischemic and 2% of hemorrhagic childhood strokes in the population were attributable to CHD.

Conclusions: CHD is an important childhood stroke risk factor. Children who undergo CHD surgery remain at elevated risk outside the perioperative period and would benefit from optimized long-term stroke prevention strategies.