Anti-TNF Therapy May Negate Heart Risk in RA

A Swedish national registry study finds rheumatoid arthritis (RA) patients who respond well to tumor necrosis factor (TNF) inhibitor therapy have an acute coronary syndrome risk similar to the matched general population, when assessed approximately 5 months into treatment over 2 years. Researchers from Umea University Hospital conducted two analyses—drawn from the Swedish Biologics Register—which included 7,704 RA patients with no history of ischemic heart disease when they started on their first tumor necrosis factor inhibitor during the years 2001 to 2010. Patients were matched by age, gender, and location to 23,112 RA patients that never took a biologic agent, and matched to a second control group consisting of 38,520 individuals in the general population. In the study, “good” response was defined via the EULAR response criteria, meaning an improvement of greater than 1.2 points in the Disease Activity Score 28 over baseline to a score of 3.2 or less at the 5-month evaluation, according to study authors. Among patients actively on TNF inhibitor therapy throughout the follow-up period, the crude incidence rate of acute coronary syndrome was 5.7 events per 1,000 person years. The crude incidence rate in biologic-naïve RA patients was 8.6 per 1,000 person years, and 3.3 per 1,000 person years in the matched general population. Compared with biologic-naïve RA patients, patients on anti-TNF therapy had a 27 percent reduction in acute coronary syndrome in a fully adjusted Cox multivariate regression analysis, factoring in socioeconomic variables. Still, patients on TNF inhibitor therapy remained at an adjusted 1.5-fold increased risk of ACS, compared with general population controls. However, this was significantly lower than the 2.3-fold elevated risk in biologic-naive RA patients, reported study authors. In a separate analysis, the investigators examined the Swedish Biologics Register subgroup of the 4,931 RA patients on anti-TNF therapy for whom EULAR response data 5 months into treatment were available. Thirty-eight percent of these patients had a EULAR good response, 37 percent had a moderate response, and 25 percent had no response. In addition, the crude incidence rate of acute coronary syndrome among patients exposed to TNF inhibitor was 6.9 cases per 1,000 years throughout 2 years of follow-up, beginning at the time of the EULAR response evaluation. The findings “make me even more concerned about the non-responding patients,” says Lotta Ljung, MD, PhD, study author and senior consultant in rheumatology at Umea University Hospital. “They have a high burden of rheumatoid arthritis disease and a higher risk of ischemic heart disease as well, but the rheumatologists might be preoccupied taking care of the first. "At this time we do not have any cardiovascular risk estimation instrument that includes active RA-disease as a variable,” adds Ljung. “A patient with RA and persisting disease activity can be regarded as having one extra cardiovascular risk factor. While waiting for a better risk evaluation tool, this must be taken into account." The study findings were initially presented at the annual meeting of the American College of Rheumatology, held Oct. 25 – 30 in San Diego, Calif. —Mark McGraw