Increased incidence of cardiovascular disease in patients with rheumatoid arthritis: results from a community based study

Abstract

Objective: To investigate the first-ever incidence of acute myocardial infarction and stroke in a community based RA cohort compared with the general population. Methods: The RA cohort consisted of all patients in a local RA register in Malmö, Sweden (n = 1022). The patients were recruited from private and hospital based rheumatology practices, and made up the absolute majority of patients with RA in the city. The general population of Malmö, aged 16 and above, served as controls. From the Swedish National Hospital Discharge Register and the national Swedish Causes of Death Register, information about all first-ever myocardial infarctions and strokes in Malmö residents between July 1997 and December 1999 was retrieved. The age and sex adjusted standardised morbidity ratio (SMR) of the two cohorts was calculated. Results: Fifty four patients with RA had first-ever myocardial infarctions or stroke during the study period, compared with 3862 subjects in the general population. The age and sex adjusted SMR was 161 (95% confidence interval (CI) 121 to 210). The first-ever incidence of cardiovascular disease was increased among female and male patients when studied separately. The increase of cardiovascular events in the RA cohort was mainly due to an excess of myocardial infarctions (n = 36; SMR = 176 (95% CI 123 to 244). Conclusion: Patients with RA in Malmö had an increased first-ever incidence of myocardial infarction or stroke compared with the general population. This confirms that cardiovascular comorbidity is of major importance in RA.