Hospitalized, medical patients with rheumatoid arthritis (RA) have a two-fold increased risk for venous thromboembolism (VTE), compared with patients who do not have RA, a US study has revealed.
“RA is not generally considered to be a risk factor for VTE, although abnormalities of coagulation factors have been found in patients with RA,” say Paul Stein and colleagues from St Joseph Mary Oakland Hospital in Pontiac, Michigan.
“Sparse data in a few patients suggest that patients with RA may have higher rates of VTE.”
To determine if the incidences of pulmonary embolism (PE) and deep vein thrombosis (DVT) are increased in hospitalized patients with RA, Stein and co-investigators obtained the number of patients discharged from hospitals throughout the USA between 1979 and 2005 with a discharge code for RA using the National Hospital Discharge Survey (NHDS).
They then determined the number of patients with PE, DVT, or VTE, which was defined as PE and/or DVT.
Among hospitalized patients with RA who did not have joint surgery, 41,000 (0.85%) of 4,818,000 had PE compared with 3,366,000 (0.38%) of 891,055,000 patients who had neither RA nor operations or joint surgery.
DVT was diagnosed in 1.64% of patients with RA and no joint surgery, compared with 0.86% who did not have RA or a joint operation.
Overall, the relative risk for VTE in medical RA patients was 1.99 compared with patients without RA or joint surgery. The risk was higher in African Americans than Caucasians and in women than men.
Interestingly, there was no difference in the risk for VTE in patients with RA who underwent surgery compared with non-RA surgical patients. Stein et al reason that this is probably due to thromboprophylaxis given prior to surgery.
“The data suggest that RA is a risk factor for VTE in hospitalized medical patients,” the researchers conclude in the journal Thrombosis and Haemostasis.
“A heightened awareness of the risks for VTE and a lower threshold for evaluation of patients for possible DVT or PE would be appropriate in caring for hospitalized patients with RA.”