Congenital heart defects raise risk of early heart attack

People born with heart defects experience their first acute heart attack at a significantly earlier age than others, according to a new national study from Lund University in Sweden. However, despite this earlier onset of illness, there is no difference in survival rates or in the risk of further heart attacks between those with congenital heart defects and others.

The study includes 214 patients with congenital heart defects who suffered their first acute myocardial infarction between 2000 and 2022. Each of the 214 patients has been matched with ten control subjects without congenital heart defects. The results have been adjusted for age, sex and key risk factors such as high blood pressure, diabetes and dyslipidaemia.

Published in the European Heart Journal, it is based on data from the Swedish quality registries for cardiac care, SWEDCON and SWEDEHART. The most striking finding is the significantly lower age at which the first acute heart attack occurs: patients with congenital heart defects fell ill on average at the age of 58, compared with 70 in the control group.

‘To suffer a heart attack twelve years earlier suggests an increased vulnerability to acquired heart disease, even though the prognosis following a heart attack does not differ between the groups,’ says Joanna Hlebowicz, associate professor of Cardiology and Adult Congenital Heart Disease at Lund University and associate consultant at the Cardiology Department at Skåne University Hospital.

The background to the study is the dramatic improvement that has taken place in Swedish cardiac care over recent decades. In Sweden, around 1,000 children are born each year with congenital heart defects of varying severity, and thanks to advanced surgery and improved follow-up care, approximately 97 per cent now survive into adulthood. This means that an ever-growing group of patients with both simple and highly complex heart defects are reaching adulthood and are therefore also at risk of developing the same age-related cardiovascular diseases as the rest of the population.

Despite the earlier age at onset, the researchers found no differences in either mortality or the risk of a further heart attack during the first year following the acute event. However, in the ten-year follow-up, a slightly higher mortality rate was observed in the group with congenital heart defects, but this difference disappeared after adjusting for other clinical factors.

‘It is important to emphasise that patients do not have a lower chance of surviving their heart attack. It is the age at which they experience the heart attack that stands out,’ says Prof Hlebowicz.

This suggests that prevention must be prioritised much earlier for this patient group. Since the risk of recurrence is not higher, but the first episode occurs at a younger age, early management of blood pressure, blood lipids, smoking and other risk factors for cardiovascular disease is crucial.

‘As more and more patients with complex heart defects reach adulthood, the healthcare system faces a new challenge: not only to treat the congenital heart defect, but also to actively monitor patients and prevent acquired heart disease later in life,’ says Prof Hlebowicz.