TNF-inhibitor drugs may reduce risk of congestive heart failure in people with rheumatoid arthritis

Rheumatoid arthritis is a chronic disease that causes pain, stiffness, swelling and limitation in the motion and function of multiple joints. Though joints are the principal body parts affected by RA, inflammation can develop in other organs as well. An estimated 1.3 million Americans have RA, and the disease typically affects women twice as often as men.

RA often is associated with a higher risk of cardiovascular disease, including an increased incidence of congestive heart failure (CHF) in this patient population. RA inflammation may be a factor in this increased CHF risk. TNF-inhibitor drugs may control RA inflammation and thereby offer protection against the onset of CHF, but past research suggested that these biologic drugs may worsen existing CHF.

Researchers in Manchester, United Kingdom, compared CHF incidence in RA patients on TNF-inhibitor therapy versus therapy with non-biologic disease-modifying antirheumatic drugs (DMARDs). Using data from patients diagnosed with RA who were enrolled in the British Society for Rheumatology Biologics Register, the researchers identified and validated 87 cases of CHF events, including 48 in 3,662 patients using DMARDs and 39 in 12,397 patients using TNF-inhibitor therapy.

"The primary aim of this study was to examine the incidence of CHF in subjects with RA treated with TNF inhibitors and to compare this to the incidence in subjects with RA treated with non-biologic DMARDs," said Alper van Sijl, PhD, of the ANIOS Interne Geneeskunde at Diakonessenhuis in Utrecht, The Netherlands, and a lead author of the study.

Potential CHF events were verified according to Framingham criteria by a cardiologist from the patients' death certificates and from clinical follow-up forms. New CHF events which occurred within six months after another cardiac event (such as a myocardial infarction) were excluded. Risk of CHF was compared between the two cohorts using a Cox regression model, propensity scores adjusted.

The researchers found a much lower incidence of CHF among patients using TNF-inhibitors. After adjustment for differences in baseline characteristics, the hazard ratio (95-percent confidence interval) of CHF in patients on TNF-inhibitors compared to non-biologic DMARDs was 0.31. The crude incidence rate of verified CHF per 10,000 person-years was 25.67 for patients using non-biologic DMARDs and only 6.27 for patients using TNF-inhibitors. Similar results were found for analysis limited to first TNF-inhibitors only and in patients without prior history of ischemic heart disease. The study's authors concluded that TNF-inhibitor therapy causes no increased risk of CHF in RA patients compared to using non-biologic DMARDs, and patients on the biologic therapy actually had a decreased risk of CHF.

"These data add to the currently available body of evidence suggesting no increased risk of CHF in subjects exposed to TNF inhibitors," says Dr. van Sijl. "A reduced risk of CHF was even noted in subjects treated with TNF inhibitors. Subjects with markers of disease severity were at the highest risk of developing CHF. Whether this result is attributable to suppression of inflammation, drug-specific effects or channeling bias remains unknown."