Tumor necrosis factor-α (TNF-α) antagonists bring about significant improvement in chronic inflammatory diseases such as rheumatoid arthritis (RA) and spondyloarthritis (SpA). There is some evidence that they can also have negative myocardial effects, but to date this issue has not been clarified. We evaluated changes in electrocardiographic measures [QT interval, corrected, dispersion, and dispersion corrected (QT, QTc, QTd, QTdc, respectively)] in patients with RA or SpA treated with anti-TNF agents (infliximab and etanercept), those treated with other biological agents (rituximab), and with methotrexate.
We studied 38 consecutive patients with RA (21 patients) or SpA (19 patients) being treated with TNF-α antagonists, 8 patients with RA being treated with rituximab, and 13 patients (8 with RA and 5 with SpA) taking methotrexate. Electrocardiographs (ECG) were performed on all participants at baseline and 12 months after initiation of treatment, and the QT, QTc, and QTd were calculated with standard procedures.
After 12 months of treatment, significant increases over baseline values were observed in the mean QT (p < 0.009), QTd (p < 0.0001), and QTdc (p < 0.0001) of the anti-TNF group, but no significant changes were observed in those taking rituximab. QT changes in the anti-TNF group were unrelated to the disease (RA vs SpA) or drug (infliximab vs etanercept), and none were associated with clinical manifestations of cardiac disease.
In patients with RA and SpA, TNF-α antagonists seem to increase the QT and QTd measures. Although these changes were completely asymptomatic, ECG may be indicated in patients being considered for anti-TNF therapy to identify those at risk for cardiac complications.