Schizophrenia Tied to 4-Fold Increase in Sudden Cardiac Death Risk

A new study revealed people with schizophrenia have a 4 times greater risk of sudden cardiac death, exceeding that of other psychiatric disorders.¹

“Patients with schizophrenia are reported to be 50% less likely to receive revascularisation for myocardial infarction,” wrote investigators, led by Jasmin Mujkanovic, from the department of cardiology at Rigshospitalet Hjertecentret, Kobenhavn in Denmark.

Studies have previously found patients with psychiatric disorders have increased all-cause mortality compared with the general population.² As for research on sudden cardiac death, research has shown youth have a 4-fold increased risk for this.³

Investigators conducted an observational study to characterize the incidence of sudden cardiac death in patients with psychiatric disorders aged 18 – 90 years.¹ They systematically reviewed all deaths in Denmark among residents aged 18 – 90 years in 2010 through death certificates and autopsy reports. Deaths were categorized as either sudden cardiac death or not.

Furthermore, psychiatric disorder diagnoses were based on either the International Classification of Diseases, 10th revision criteria, or having a prescription for psychotropic medication within 1 year. They also collected data on comorbidities, such as heart failure, arrhythmic disease, peripheral artery disease, ischaemic heart disease, cerebrovascular disease, diabetes, and other cardiovascular disease.

The study included 45,703 deaths (6002 sudden cardiac deaths) of which 3683 were among the general population and 2319 among patients with a psychiatric disorder. The incidence rate ratio of sudden cardiac death was 1.79 – 6.45 times greater among patients with psychiatric disorders than the general population (P < .001) when taking in consideration age groups. Without considering age groups, the risk of sudden cardiac death was 3.53 times greater across those with psychiatric disorders than the general population.

After adjusting for age, sex, and comorbidities, psychiatric disorders were independently linked to sudden cardiac deaths (hazard ratio [HR], 2.31; 95% confidence interval [CI], 2.19 to 2.43; P < .001). The sudden cardiac disease risk was greatest among patients with schizophrenic disorders (HR, 4.51; 95% CI, 3.95 to 5.16; P < .001) than with depressive disorders (HR, 2.10; 95% CI, 1.92 to 2.30; P < .001) and bipolar disorder (HR, 2.93; 95% CI< 2.36 to 3.62; P < .001).

Once accounted for relevant comorbidities, the hazard risk for patients with sudden cardiac death and psychiatric disorder was 2.08 (95% CI, 1.74 to 2.49; P < .001). Additionally, psychiatric disorders were significantly linked to non-sudden cardiac death mortality when adjusted for comorbidities (HR, 2.81; 95% CI, 2.75 to 2.86; P < .001).

Investigators wrote the high prevalence of comorbidities in people with psychiatric disorders highlights the complexity of the connection between mental health and cardiovascular death.

“A patient with a psychiatric disorder is more disposed to have an unhealthy lifestyle, with unhealthy food habits, smoking, alcohol or substance abuse, and low adherence to exercise as well as obesity, a known side effect of tricyclic antidepressant or antipsychotic agents,” investigators wrote. “All these factors independently can lead to the development of conditions such as hypertension, atherosclerosis, and ischaemic heart disease.”

The study also observed that 18-year-old patients with a psychiatric disorder had their life expectancy reduced by approximately 10 years. Patients aged 18 – 40 years with psychiatric disorders had 13% of their years lost due to sudden cardiac death.

“These results highlight the importance of thoroughly following up patients with a psychiatric disorder, focusing on cardiometabolic factors and ECG monitoring, to treat risk factors associated with SCD, in order to prevent premature death,” investigators wrote.

References

1. ^{Mujkanovic J, Warming PE, Kessing LV, et al. Heart Epub ahead of print: 22 October 2024. doi:10.1136/ heartjnl-2024-324092}
2. ^{Andersen PK. Life years lost among patients with a given disease. Stat Med 2017;36:3573–82.}
3. ^{Risgaard B, Waagstein K, Winkel BG, et al. Sudden cardiac death in young adults with previous hospital- based psychiatric inpatient and outpatient treatment: a nationwide cohort study from Denmark. J Clin Psychiatry 2015;76:e1122–9.}