The effect of systemic psoriasis therapies on the incidence of myocardial infarction: a cohort study

Background Psoriasis confers an independent risk of cardiovascular disease that is likely to be related to systemic inflammation. Anti-inflammatory treatment could theoretically reduce the risk of cardiovascular disease, and initial data suggest that treatment may reduce the incidence of cardiovascular risk factors. Objectives To determine the impact of anti-inflammatory therapy on the risk of acute myocardial infarction (MI) in patients with moderate-to-severe psoriasis. Methods Cohort study using administrative and pharmacy claims data from a large U. S. insurer comparing patients with psoriasis aged >= 18 years receiving systemic immunomodulatory therapies (methotrexate, ciclosporin, alefacept, efalizumab, adalimumab, etancercept and infliximab) with a control group treated with ultraviolet B phototherapy that has limited systemic anti-inflammatory effects. The risk of acute MI was calculated using a proportional hazards model while controlling for sex, age, hypertension, hyperlipidaemia, diabetes and depression. Significant interaction terms were included in the final model. Results The study group included 25 554 patients with psoriasis receiving systemic treatment or phototherapy. There was a trend towards an increased risk of MI in the systemic treatment group but not a significant difference in overall MI risk [hazard ratio (HR) 1.33, 95% confidence interval (CI) 0.90-1 96]. Additionally, there was a significant interaction with age: in patients under 50 years the HR for MI if receiving systemic therapy was 0.65 (95% CI 0.32-1.34), and in patients aged 50-70 years it was 1.37 (95% CI 0.79-2.38). Conclusions Overall, there does not appear to be a reduced risk of MI in patients with psoriasis receiving systemic therapy compared with a group undergoing phototherapy. The risk of MI may vary by age.