Nationwide burden of sudden cardiac death among patients with a psychiatric disorder

Patients with psychiatric disorders have increased all-cause mortality compared to the general population. Previous research has shown that they have a 4-fold increased risk of sudden cardiac death (SCD) among the young. However, the risk across all age groups remains unknown.

To investigate the incidence of SCD in patients with psychiatric disorders aged 18-90 years in the Danish population by systematically reviewing all deaths in one year.

We examined all deaths in Denmark among residents aged 18-90 years in 2010 by reviewing death certificates and autopsy reports. All deaths were categorized as non-SCD, or SCD, based on the available information. Psychiatric disorder was defined according to ICD-10 criteria, or by redemption of a prescription for psychotropic medication within one year prior to death.

Out of 4.3 million residents in 2010 aged 18-90 years, we observed 45 703 deaths of which 6 002 were SCD. Overall, the incidence of SCD was 4.35 times (CI: 4.20-4.50, p-value <0.001) higher among patients with psychiatric disorders than in the general population and was age dependent (p-value <0.001). When adjusting for age, sex, and comorbidities, psychiatric disorders were independently associated with SCD, with a hazard ratio (HR) of 2.46 (2.33-2.60, p-value: <0.001), with highest SCD risk among patients suffering from schizophrenic disorders with a HR of 5.27 (4.23-6.56 p-value <0.001). Furthermore, patients with psychiatric disorders had an expected 10-year excess loss of life of which 13% was caused by SCD.

The rate of SCD in patients with psychiatric disorders was 4 times higher than in the general population. Having a psychiatric disorder is independently associated with SCD. Life-expectancy for an 18-year-old with a psychiatric disorder is projected to be 10-years shorter in comparison.

Incidence rate of SCD by age group