Background/Purpose: Rheumatoid arthritis (RA) patients have an increased risk of cardiovascular diseases (CVD). The underlying mechanism is partly explained by the inflammation process in both RA and atherosclerosis. Atherosclerosis is an important risk factor for the occurrence of premature coronary heart disease, like myocardial infarction (MI) (1). A higher average level of disease activity in RA patients might cause MI, however this hypothesis was not confirmed (2). Probably, flares are more important than the average level of disease activity as risk factor for CVD in RA. Therefore, the objective was to determine whether the annual flare rate is associated with the occurrence of MI in RA patients.

Methods: We used case-control data from a large Dutch prospective RA cohort, which started in 1985. Medical files of RA patients were used to determine the occurrence of MI events. Patients were defined as cases at the moment they experienced a MI event. Randomly chosen RA controls were matched on disease duration; the time between RA diagnosis and MI event or censoring. Flares were defined as an increase in DAS28>1.2 or >0.6 if DAS28≥3.2. The annual flare rate was calculated as the number of flares divided by disease duration. Other important characteristics of RA and risk factors for CVD were determined at baseline or during follow-up. Characteristics of cases and controls were compared by t-tests or non-parametric Mann-Whitney U. Logistic regression was performed to determine the crude association between the annual flare rate and occurrence of MI. Confounding variables were taken into account using multivariate logistic regression.

Results: The study population consisted of 41 cases and 181 matched controls. Cases were older and more frequently male while also risk factors for CVD were raised in cases, like: significantly higher BMI, total cholesterol, triglyceride, LDL, atherogenic index, incidence of hypertension and, a significantly lower HDL, compared to controls. Other characteristics like smoking status, disease duration, average DAS28, C-reactive protein levels, rheumatoid factor positivity, prevalence of diabetes mellitus, and medication use did not differ significantly between cases and controls. The crude OR of the annual flare rate and the occurrence of MI was 0.78 (95% CI: 0.48; 1.25). The OR adjusted for age, LDL, male gender, cholesterol, hypertension, and HDL was 0.97 (95% CI: 0.58; 1.68).

Conclusion: No significant association was found between annual flare rate and the occurrence of MI in RA patients. This implies that the presence of flares in disease activity does not contribute to the increased CVD risk in RA patients, in contrast to expectations.

1.            Kitas GD, Gabriel SE. Cardiovascular disease in rheumatoid arthritis: state of the art and future perspectives. Annals of the rheumatic diseases. 2011;70(1):8-14.

2.            Radovits BJ, Popa-Diaconu DA, Popa C, Eijsbouts A, Laan RF, van Riel PL, et al. Disease activity as a risk factor for myocardial infarction in rheumatoid arthritis. Annals of the rheumatic diseases. 2009;68(8):1271-6.

« Back to 2015 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/flares-of-disease-activity-as-risk-factor-for-the-occurrence-of-myocardial-infarction-in-patients-with-rheumatoid-arthritis/