Adults with congenital heart disease at increased stroke risk

By Bianca Nogrady
Adults with a history of congenital heart disease are at significantly greater risk of stroke than the general population, a Canadian study has found.

A retrospective study of 29,638 adults with congenital heart disease showed the risk of ischaemic stroke was 12-fold greater in women and ninefold greater in men with congenital heart disease before the age of 54 years, compared with the age-standardised general population. The risk of haemorrhagic stroke was fivefold higher in women and more than sixfold higher in men with congenital heart disease before the age of 54 years.

The risks of ischaemic and haemorrhagic stroke were also increased in individuals with congenital heart disease aged 55 to 64 years, but to a much lesser degree, according to the study findings, published in Circulation.

The greatest risk factors for stroke among individuals with congenital heart disease were heart failure (which had a relatively greater impact in those aged 18 to 49 years), diabetes and recent myocardial infarction. Severe and left-sided cardiac lesions were also associated with a higher cumulative risk of stroke during adulthood than shunt- and right-sided lesions.

Commenting on the study, molecular cardiologist Professor Diane Fatkin said that although the finding of an increased risk of stroke was not in itself unexpected, the risk factors were.

‘The most surprising finding was that the risk factors for stroke were not directly related to any aspects of the underlying congenital heart disease,’ said Professor Fatkin, from the Victor Chang Cardiac Research Institute in Sydney. ‘So it didn’t find that a major risk factor is having a large atrium or history of arrhythmia – factors that we might expect could be potential complications of the congenital heart disease.’

Professor Fatkin told Medicine Today this was most likely because some of the potential congenital heart disease-related risk factors were absorbed into the dominant risk factor of heart failure.

‘For example, atrial fibrillation is something we would expect as a complication of many types of congenital heart disease but atrial fibrillation might have been buried by the heart failure term,’ she said.

Professor Fatkin said the bottom line of the study was that adults with a history of congenital heart disease should automatically be considered at high risk of stroke and managed accordingly.

Circulation 2015; 132: 2385-2394.

Picture credit: © Zephyr/SPL.