A Danish study shows that the lifetime risk of sudden cardiac death is more than four times higher for people with schizophrenia

The lifetime risk of unexpected and sudden death from a cardiovascular cause in the absence of pre-existing heart disease – known as sudden cardiac death – is more than four times higher for people with schizophrenia than for the general population, according to Danish research published online in the magazine Heart.

The risk is still around twice as high for people with other forms of mental health problems, such as depression, regardless of age, according to findings which suggest an 18-year-old can expect to live around 10 years less than someone of the same age. age. age without psychological problems.

The research to date suggests that young people with psychiatric illness are at increased risk of sudden cardiac death, but it is not clear whether that risk extends across the lifespan or whether certain mental disorders are associated with greater risk.

To find out, the researchers systematically reviewed all deaths among 18 to 90-year-old Danish residents over the course of 2010, relying on information from death certificates and post-mortem reports.

Mental disorders in the past ten years were defined according to the criteria of the International Classification of Diseases or based on prescriptions for psychotropic drugs filled in the previous year.

During 2010, 45,703 people between the ages of 18 and 90 died. A total of 6,002 of these deaths were classified as sudden cardiac death: 3,683 among the general population and 2,319 among people with mental illness.

People with mental disorders typically had a range of potentially influential risk factors. They tended to be older and female, and were more likely to have coexisting conditions such as cardiovascular disease, heart failure, arrhythmias and diabetes.

Overall, the rate of sudden cardiac death was up to 6.5 times higher among people with mental disorders than among the general population. Although cases were higher in all age groups, the gap narrowed in the oldest age groups.

After taking age, gender and co-existing conditions into account, mental health problems were nevertheless independently associated with a doubling of the risk of sudden cardiac death.

The risk was twice as high in people with depression, three times higher in people with bipolar disorder and 4.5 times higher in people with schizophrenia.

Mental disorders were also significantly associated with death from other causes (nearly 3.0 times the risk) and with shorter lifespan.

Based on the findings, the researchers estimated that an 18-year-old with any form of psychiatric disorder would live about 10 years less than someone of the same age without either of these conditions – 68 instead of 78.

And they estimate that a 70-year-old could live another ten years, compared to another fourteen years in the general population.

Until the age of about 40 years, sudden cardiac death explained about 13% of the difference in reduced lifespan.

This is an observational study and therefore no firm conclusions can be drawn about causal factors, the researchers warn.

People with psychiatric disorders are more likely to lead unhealthy lifestyles, and one of the side effects of the prescribed medications is weight gain – all factors that predispose to the development of conditions such as high blood pressure and heart disease, the researchers explain.

But the fact that the association between mental disorders and sudden cardiac death persisted even after adjusting for these influential factors “suggests that comorbidities, such as cardiovascular disease, are not the only mediators contributing to the higher risk of cardiovascular disease.” . [sudden cardiac death]”, they write.

In a linked editorial, Drs. Aapo Aro and Jarkko Karvonen from Helsinki University Hospital said that although the study “expands our understanding of [sudden cardiac death] risks within the vulnerable population of psychiatric patients”, the design means that “the underlying mechanisms lie behind it”. [sudden cardiac death] remain largely speculative.”

Sudden cardiac death is preceded by symptoms in about half of those affected. “If these symptoms are not ignored but responded to promptly, this translates into a fivefold increased survival after cardiac arrest,” they explain.

Detecting and addressing these symptoms in the mentally ill may be even more difficult than in other groups of patients, they add, but suggest that AI and wearable electronic devices could identify those most at risk in the not-so-distant future. and possibly save their lives.