Patients with rheumatoid arthritis (RA) are twice as likely to experience a myocardial infarction (MI) over a 3-year period compared with patients with noninflammatory rheumatic disorders, according to data from the Wichita, Kansas-based National Data Bank for Rheumatic Diseases.
However, say co-authors Dr. Frederick Wolfe and Dr. Kaleb Michaud, the only factor that accounted for the increased risk was corticosteroid use among patients with the inflammatory disease.
The prospective cohort study, described in the September issue of Arthritis & Rheumatism, included 17,738 patients with rheumatic arthritis and 3001 patients with noninflammatory rheumatic disorders assessed at 6-month intervals between 1999 and 2006.
There were 223 first MIs in the RA group and 25 in the non-RA group during a mean follow-up period of 3.0 years (adjusted hazard ratio 1.9, p = 0.005).
Conventional cardiovascular risk factors predicted incident MI to a similar degree in the two groups.
The only treatment associated with increased MI risk was prednisone. There was a dose-response relationship, such that patients receiving > 5 mg/day were at significantly greater risk than those treated with lower doses (p = 0.031). When RA patients treated with prednisone were excluded from the analysis, the difference in risk between the two groups was no longer statistically significant.
"Neither anti-TNF therapy nor any other therapy was significantly associated with MI risk in any analysis," Drs. Wolfe and Michaud report. Of note, anti-TNF therapy did not appear to exert any protective effect, as had been hoped.
Arthritis Rheum 2008;58:2612-2621.