Background Patients with rheumatoid arthritis (RA) die prematurely from cardiovascular disease (CVD) with persistent inflammation likely playing an important role in the development of atherosclerosis. Conversely, induction of remission reduces CVD risk in RA. Methotrexate (MTX) monotherapy induces remission in 20% of RA patients v 55-80% remission with Tumour Necrosis Factor inhibitors (TNFi) and MTX combination therapy.
Objectives (1) To evaluate the number of Myocardial Infarctions (MI) in RA patients discharged from hospital from 1995 to 2010; and (2) to assess any association with therapy, including TNFi usage.
Methods The Hospital In-Patient Enquiry system (HIPE), a national system recording information on hospital bed utilization, was evaluated from 57 hospitals from 1995-2010 for patients admitted with a diagnosis of RA. Age group, number of inpatient days, gender and reason for admission (ICD codes) were also recorded. Annual prescription data for TNFi usage nationally was separately analysed from 2000 to 2010. Descriptive analyses are presented as totals, mean (standard deviation (SD)) and mean % change. Correlations were examined by Spearman’s rho; p<0.05 was considered statistically significant.
Results 57,774 inpatient records in RA patients were reviewed from 1995-2010; F: M 2:1, mean age 66 (16). A total of 807 RA patients were discharged following admission for MI in this time period; F:M 1.4:1, mean age 71 (10). 53 per annum (pa) MI’s in RA were recorded from 1995-2000, increasing to 77pa up to 2004, with a subsequent 8%pa reduction to 2010 when 29 were recorded, reflecting a total 62% reduction in the annual incidence of MI’s in RA. At a national level, the total number of MI’s discharged pa increased from 6492 in 2000 to 8052 in 2010. The incidence ratio of MI’s in RA to total MI’s nationally decreased by 66% from 0.012 to 0.004 in this same period. Annual TNFi prescribing has increased by 156% per annum (pa) from 2389 units in 2000 to 116,747 in 2010. Increased prescription of TNFi negatively correlated with the annual incidence of MI in pt’s with RA (r=-0.7, p=0.015). Where information was available nationally (33% population), there was a trebling in the prescription of MTX from 2000-2010.
Conclusions Increased prescription of TNFi drugs and likely also MTX has coincided with a 62% reduction in the annual incidence of MI’s in RA despite escalating national MI rates. Prescription of TNFi drugs strongly negatively correlated with the annual incidence of MI’s in RA with a concurrent increase in the prescription of MTX. It is recognised that factors other than TNFi usage, such as better control of traditional CVD risk factors may also have contributed to these improved patient outcomes.
Disclosure of Interest None Declared