Disease Activity and Increased Risk of Cardiovascular Death among Patients with Psoriatic Arthritis

Objective. Recent studies indicate increased cardiovascular (CV) morbidity and mortality in patients with psoriatic arthritis (PsA), but results are inconsistent. This prompted our investigation of the mortality rate, cause of death, and incidence of acute CV events in patients from northern Sweden with PsA. Methods. Patients with established PsA (464) were included. To calculate standardized mortality ratio (SMR) and standardized incidence ratio (SIR) for CV events, data were extracted from the National Causes of Death Register and the National Inpatient Care Register in Sweden, and compared with the general population. The study period was 1995-2011. To study the effect of inflammatory activity, a composite disease activity index (DAI) was used. Results. The SMR (95% CI) for overall mortality and diseases of the circulatory system (International Classification of Diseases, 10th edition; I00-I99) was 1.22 (0.89-1.63) and 1.64 (1.02-2.52), respectively. In regression analysis, DAI was significantly associated with death (OR 1.99, 95% CI 1.41-2.80) when adjusted for age and sex (p < 0.001), and remained significant after stratifying patients into the 2 major causes of death: diseases of the circulatory system and malignant neoplasms. Peripheral and axial disease was associated with death (OR 4.02, 95% CI 1.84-8.84, p < 0.001) compared with peripheral disease only. The SIR (95% CI) for a CV event (myocardial infarction or stroke) was 0.597 (0.40-0.86); this association was only significant in men. Conclusion. Patients with PsA had a small but significant increase in SMR for death due to diseases of the circulatory system compared with the general population. Among patients, death was associated with DAI, as well as axial involvement in combination with peripheral disease, indicating more aggressive disease phenotypes.