The lifetime risk of experiencing a sudden and unexpected death from a cardiovascular cause, known as sudden cardiac death, is more than four times greater in individuals with schizophrenia compared to the general population, as highlighted by recent Danish research published in the journal Heart.
This elevated risk persists, albeit at a reduced ratio of approximately two times higher, for those suffering from other forms of mental ill health, such as depression, regardless of age. The study findings reveal a concerning expectation that 18-year-olds with mental health issues may live around 10 years less than their peers without such conditions.
The focus of the research was to evaluate whether the heightened risk of sudden cardiac death among young individuals with psychiatric illnesses extends across their entire lifespan and if certain mental health disorders pose a greater risk than others. To this end, researchers conducted a systematic review of all deaths from sudden cardiac causes among Danish residents aged 18 to 90 in 2010, using data extracted from death certificates and autopsy reports.
Mental health conditions within the decade leading up to the study were identified either through the International Classification of Diseases criteria or via prescriptions for psychotropic drugs issued within the year prior.
In 2010 alone, out of 45,703 deaths among individuals aged between 18 and 90, 6002 were determined to be sudden cardiac deaths. Of these, 2319 occurred in individuals with a diagnosed mental illness, compared to 3683 in the general population. Those with mental health disorders often presented multiple risk factors, such as older age, female gender, and co-existing medical conditions like cardiovascular disease, heart failure, arrhythmias, and diabetes.
The incidence of sudden cardiac death was notably higher—up to 6.5 times—in those with mental health disorders across all age groups, although the disparity lessened in older demographics. Even after adjusting for factors like age, sex, and pre-existing health conditions, mental ill health remained independently linked to a doubled risk of sudden cardiac death. Specifically, the risk was doubled for those with depression, tripled for people living with bipolar disorder, and increased 4.5 times for those with schizophrenia.
Furthermore, mental health disorders are significantly correlated with deaths from other causes, nearly tripling the risk and contributing to a shortened overall lifespan. Based on their findings, the researchers estimated that an 18-year-old with a psychiatric disorder might expect a life expectancy reduced by about ten years — 68 years compared to 78 for someone without such conditions. Similarly, a 70-year-old might anticipate living another 10 years versus 14 more years for someone in the general population.
Interestingly, sudden cardiac death accounted for approximately 13% of the disparity in reduced lifespan up to the age of about 40. While the observational nature of this study prevents definitive conclusions about causality, the researchers suggest that factors such as an unhealthy lifestyle and side effects from psychiatric medications, like weight gain, may predispose individuals to conditions like high blood pressure and heart disease.
Despite adjustments for these risk factors, the persistent association between mental health disorders and sudden cardiac death indicates that comorbidities such as cardiovascular disease are not the sole contributors to this increased risk, as stated in the research.
In an associated editorial, Drs. Aapo Aro and Jarkko Karvonen of Helsinki University Hospital commend the study for significantly enhancing our understanding of the risk of sudden cardiac death within this vulnerable population. However, they note that the study’s design means the underlying mechanisms behind sudden cardiac death remain primarily speculative.
The editorial also highlights that sudden cardiac death is often preceded by symptoms in about half of the affected individuals. Prompt recognition and action upon these symptoms can lead to a fivefold increase in survival rates following a cardiac arrest. This recognition and response might be even more challenging among the mentally ill. Still, future advancements in technology, such as AI and wearable electronic devices, may soon offer new ways to identify those at the highest risk and potentially save lives.
More information: Jasmin Mujkanovic et al, Nationwide burden of sudden cardiac death among patients with a psychiatric disorder, Heart. DOI: 10.1136/heartjnl-2024-324092
Journal information: Heart Provided by BMJ Group
