OP0164 THE RISK OF MYOCARDIAL INFARCTION IS SIMILAR IN RHEUMATOID ARTHRITIS AND DIABETES – A NATIONWIDE COHORT STUDY
J. Lindhardsen 1,*G. H. Gislason 1O. Ahlehoff 1O. R. Madsen 2P. R. Hansen 1
1Dep. of Cardiology, 2Dep. of Rheumatology, GENTOFTE UNIVERSITY HOSPITAL, Hellerup, Denmark
Background: Rheumatoid arthritis (RA) is now considered an independent risk factor for cardiovascular disease (CVD), presumably by shared pathways of inflammation in atherosclerosis and RA. Recent studies indicate the excess risk of CVD in RA is equivalent to the risk of CVD in diabetes mellitus (DM), but the study designs and sample sizes restrict the interpretation of these findings in regard to the management of CVD in the RA population.
Objectives: To compare the incidence of myocardial infarction (MI) in RA patients and DM patients on a nationwide scale.
Methods: The study population included the entire Danish population >= 10 years of age on January 1, 1997 (n=4.614.840). Patients with incident DM and RA were identified according to prescription claims, hospitalizations and outpatient clinics visits, by individual-level-linkage of nationwide administrative registers of hospitalizations and drug dispensing from pharmacies. The population was followed until first MI or December 31, 2006. Risk of MI was analyzed by a multiple Poisson regression models adjusting for calendar year of incidence, pharmacological cardiovascular treatment, Charlsons comorbidity score and socioeconomic status.
Results: A total of 10.300 and 132.189 people developed RA and DM, respectively, during the study period. The overall Incidence rate ratio (IRR) of experiencing an MI after developing RA was increased to 1.75 ([95% confidence interval] 1.56-1.96), which was comparable to the increased risk of MI after developing diabetes of 1.89 (1.80-1.98). After stratifying by gender the risk in the RA & DM population remained comparable for male patients (RA 1.74 [1.44-2.02]; DM 1.79 [1.66-1.88]) while the risk for female RA patients was slightly lower than for female DM patients (RA 1.62 [1.36-1.87]; DM 1.98 [1.83-2.13]), though still substantially elevated.
When further stratifying by age the risk of MI were considerable higher in the younger RA patients compared to the older age groups (Table). This was most pronounced in female RA patients where the youngest age group showed more than a six-fold increase in MI events compared to the general population, slightly higher than in the diabetes group.
Table: Incidence risk ratios [IRR (95% confidence intervals)] for MI in RA and DM compared to the general population | ||||
|
|
Male |
Female | ||
|
Age |
RA |
DM |
RA |
DM |
|
<44 |
0.65 (0.09-4.69) |
3.81 (2.91-4.99) |
6.87 (1.13-15.00) |
5.70 (3.70-8-85) |
|
45-54 |
2.38 (1.56-3.61) |
2.00 (1.73-2.33) |
2.40 (1.40-4.11) |
3.23 (2.48-4.20) |
|
55-64 |
1.58 (1.11-2.24) |
1.63 (1.45-1.84) |
1.66 (1.15-2.39) |
2.09 (1.74-2.40) |
|
65-74 |
1.90 (1.45-2.49) |
1.71 (1.53-1.90) |
1.59 (1.21-2.09) |
2.00 (1.75-2.29) |
|
>75 |
1.33 (0.91-1.95) |
1.63 (1.44-1.85) |
1.31 (0.99-1.73) |
1.66 (1.47-1.88) |
Conclusion: RA is an independent risk factor for myocardial infarction of similar magnitude as diabetes mellitus, and the risk is especially high among younger patients with RA. These results underline the importance of early and aggressive detection and management of cardiovascular risk factors in patients with RA.
Disclosure of Interest: None declared