Increased incidence of and impaired prognosis after acute myocardial infarction among patients with seropositive rheumatoid arthritis.

OBJECTIVE

To examine the incidence and outcome of acute myocardial infarction (AMI) in patients with rheumatoid arthritis compared with the general population, and to examine whether care and treatment of an AMI differs between patients and controls.

METHODS

The Multinational Monitoring of Trends and Determinants of Cardiovascular Disease register for northern Sweden was used to compare those incidences of AMI in a cohort of patients with rheumatoid arthritis with that in the general population. 35 patients with rheumatoid arthritis who had also experienced an AMI were identified. For each patient with rheumatoid arthritis, three controls with a history of AMI but without rheumatoid arthritis were randomly selected from the same register, and matched for age, sex and year of the AMI for evaluation of case fatality and potential differences in treatment of AMI.

RESULTS

The standardised incidence ratio for AMI was 2.9 in patients with rheumatoid arthritis compared with the general population (p<0.05). During the first 10 years after an AMI, patients with rheumatoid arthritis had a higher overall case fatality compared with controls (hazard ratio (HR) 1.67, 95% confidence interval (CI) 1.02 to 2.71). Survival time was decreased in the rheumatoid arthritis group compared with controls despite the same care and treatment.

CONCLUSION

Both the incidence of and case fatality after an AMI were higher among patients with rheumatoid arthritis than among the general population. The results emphasise the necessity of optimising the preventive, diagnostic and caring strategies for AMI in rheumatoid arthritis.