Coronary heart disease (CHD) is the main cause of excess premature mortality in patients with schizophrenia; the mortality rate from coronary heart disease in patients with schizophrenia is 50–75%, compared with 33% in the general population.[Hennekens et al., 2005] Patients with schizophrenia are known to have enhanced risk of developing several conditions or comorbidities that increase the risk of heart disease, including smoking, dyslipidaemia, diabetes, obesity, and metabolic syndrome.[Correll, 2007; De Hert et al., 2009; Hennekens et al., 2005; Sadock et al., 2009]

References:
Correll C. Balancing efficacy and safety in treatment with antipsychotics. CNS Spectrums 2007; 12 (10 Suppl 17): 12–20, 35.

De Hert M, Dekker JM, Wood D, et al. Cardiovascular disease and diabetes in people with severe mental illness position statement from the European Psychiatric Association (EPA), supported by the European Association for the Study of Diabetes (EASD) and the European Society of Cardiology (ESC). Eur Psychiatry 2009; 24 (6): 412–424.

Hennekens CH, Hennekens AR, Hollar D, Casey DE. Schizophrenia and increased risks of cardiovascular disease. Am Heart J 2005; 150 (6): 1115–1121.

Sadock BJ, Sadock VA, Ruiz P (eds). Kaplan & Sadock’s Comprehensive Textbook of Psychiatry. 9th Edition. Vol 1–2. © Lippincott Williams & Wilkins, 2009.