Sudden cardiac death in people with schizophrenia: higher risk, poorer resuscitation profiles and differing pathologies

Abstract

Abstract Background People with schizophrenia account for approximately 1.0% of the population and appear to experience increased rates of sudden cardiac death (SCD). This study determined characteristics of increased SCD in people with schizophrenia. Methods A prospective state-wide registry compared people aged 15-50 years with and without schizophrenia who experienced SCD within a two-year time-period and were referred for forensic evaluation. Results 579 individuals were identified, of whom 65 (11.2%) had schizophrenia. Patients with schizophrenia were more commonly smokers (46.2% vs 23.0%, p<0.0001), consumed excess alcohol (32.3% vs 21.4%, p=0.05), and used QTc-prolonging medications (69.2% vs 17.9%, p<0.0001). They were less likely to arrest while exercising (0.0% vs 6.4%, p=0.04). Unfavourable arrest-related factors included lower rates of witnessed arrest (6.2% vs 23.5%, p<0.0001), more likely to be found in asystole (92.3% vs 73.3%, p<0.0001), and being more likely to be found as part of a welfare check after a prolonged period of time (median 42 vs 12 hours, p=0.003). There was more frequent evidence of decomposition, and they more commonly underwent autopsy (41.2% vs 26.4%, p=0.04 and 93.8% vs 82.5%, p=0.05), with diagnosis of non-ischaemic cardiomyopathy being more common (29.2% vs 18.1%, p=0.04). Conclusion People with schizophrenia account for 11% of young SCD patients referred for forensic investigations, exceeding population rates eleven-fold. They have higher pre-existing cardiac risk factor burden, unfavourable resuscitation profiles and higher rates of non-ischaemic cardiomyopathy. Strategies targeting biopsychosocial support may deliver not only psychological benefits but also help reduce unwitnessed cardiac arrest.