Although red cell distribution width is a good prognostic indicator for cardiovascular disease and survival, its predictive value is negated among patients who are treated with methotrexate for rheumatoid arthritis, according to findings published in BMC Rheumatology.
“Because [methotrexate] is well known to affect folic acid metabolism, [methotrexate] treatment can result in alterations of [mean corpuscular volume], which may impact on [red cell distribution width], as [mean corpuscular volume] levels feed into [red cell distribution width] calculation,” Julia Held, MD, of the Medical University of Innsbruck, Austria, and colleagues wrote. “We thus questioned, whether [red cell distribution width] levels and subsequently its diagnostic utility and potential in RA subjects, as reported before, are influenced by ongoing [methotrexate] therapy.”
To determine the impact of disease modifying drugs (DMARD) — specifically methotrexate — on red cell distribution width’s predictive value regarding CV conditions among patients with RA, the researchers evaluated 385 participants from the Medical University of Innsbruck in a retrospective analysis. The researchers collected data on medical treatment, disease activity, laboratory parameters and CV history both at the onset of RA and at their last follow-up visit to the clinic.
Although red cell distribution width is a good prognostic indicator for cardiovascular disease and survival, its predictive value is negated among patients who are treated with methotrexate for RA, according to researchers.
The researchers recorded data from patients with CV events at the last follow-up visit prior to the event. Severe CV events were defined as myocardial infarction with or without ST-wave elevation, or ischemic stroke. Red cell distribution width was evaluated at initial diagnosis, during follow-up visits between 2009 and 2016, and prior to a CV event.
According to the researchers, older age (P <.001), longer disease duration (P = .002) and higher red cell distribution width at diagnosis (P = .025) were associated with a severe CV event. In addition, there were no differences in red cell distribution width levels following treatment with any drug beside methotrexate. Patients treated with methotrexate demonstrated significantly higher red cell distribution width compared to those who did not receive the drug (P < .001). Patients with RA who did not receive methotrexate had red cell distribution width levels that were significantly different based on whether they had a CV event. This difference did not appear among patients treated with methotrexate.
“As far as we know, this is the first study evaluating the influence of [conventional synthetic] DMARDs on [red cell distribution width],” Held and colleagues wrote. “Our study approves [red cell distribution width] at initial diagnosis of RA as a risk predictor for serious CV events but also indicates that its predictive value is lost during follow up in patients receiving [methotrexate] therapy, whereas it remains valid in subjects receiving non-[methotrexate] containing treatments.” – by Jason Laday
Disclosure: The researchers report no relevant financial disclosures.