Sudden Cardiac Death in Young Adults With Previous Hospital-Based Psychiatric Inpatient and Outpatient Treatment: A Nationwide Cohort Study From Denmark

Introduction: Psychiatric patients have premature mortality compared to the general population. The incidence of sudden cardiac death (SCD) in psychiatric patients is unknown in a nationwide setting. The aim of this study was to compare nationwide SCD incidence rates in young individuals with and without previous psychiatric disease.

Method: Nationwide, retrospective cohort study including all deaths in people aged 18–35 years in 2000–2006 in Denmark. The unique Danish death certificates and autopsy reports were used to identify SCD cases. Psychiatric disease was defined as a previous psychiatric hospital contact and was identified using The Danish Psychiatric Central Research Register. All diagnoses in Danish registries are coded according to ICD-8 or ICD-10. All hospital records were retrieved manually.

Results: Among 5,178 deaths, 395 were due to SCD and autopsies were performed on 262 (66%). In 77 SCD cases, a previous psychiatric hospital contact was identified. The SCD incidence rate in psychiatric patients was 14.8 (95% CI, 11.7–18.5) per 100,000 person-years versus 3.8 (95% CI, 3.4–4.3) per 100,000 person-years in individuals without psychiatric hospital contact (incidence rate ratio = 3.9; 95% CI, 3.0–5.0; P < .01). Incidence rates per 100,000 persons-years were the highest in patients with schizophrenia-spectrum disorders (38.9; 95% CI, 26.4–55.2) and substance-related disorders (31.6; 95% CI, 19.3–48.8). SCDs in psychiatric patients compared to nonpsychiatric patients were more often unexplained (65% vs 40%, P = .02), and cardiac symptoms were reported prior to death in 46% of psychiatric patients.

Conclusions: Patients with prior psychiatric hospital contact have a 4-fold increased risk of SCD. Since almost 50% had possible cardiac symptoms prior to death, cardiovascular risk monitoring and management in the mentally ill are essential.

J Clin Psychiatry 2015;76(9):e1122–e1129