TNF-α, rheumatoid arthritis, and heart failure: a rheumatological dilemma

Cardiovascular disease (CVD) is responsible for 35-50% of rheumatoid arthritis (RA) deaths, whereas, in the general UK adult population, coronary heart disease is responsible for 1/4 deaths in males and 1/5 deaths in female. This increased risk may be attributable to RA-specific risk factors such as hyperhomocysteinemia, disease-related dyslipidemia or vascular inflammation, or to morbidity related to medications and high levels of tumor necrosis factor-α (TNF-α). The possible roles of TNF-α in the development of atherosclerosis include the recruitment of inflammatory cells to the site of injury or the promotion of adverse vascular smooth muscle cell remodelling. TNF-α may also act as a proinflammatory factor in plaque rupture. Anticytokine therapy could prove beneficial in the treatment of patients with heart failure. While early studies supported this hypothesis, anti-TNF strategies have not demonstrated salutary benefits in large multicenter randomized and placebo-controlled clinical trials in patients with symptomatic heart failure. There is a variety of possible explanations for the failure of anti-TNF therapy: (1) TNF antagonism has untoward effects in the setting of heart failure; (2) the biological agents used in the trials were intrinsically toxic; (3) sex and race may have important implications in the outcome after anticytokine therapy; (4) the TNF-α protein contains a polymorphism, and, in fact, genoma plays a role in modifying the pharmacologic response to anticytokines; (5) anti-TNF-α approaches could have had pharmacodynamic interactions with other heart failure medications; and (6) the patients in these trials may have been inappropriately selected. These disappointing results may determine controversial attitude in the long-term treatment with anti-TNF agents in RA or Crohn's disease. The effects of TNF-α blockers on incident cases of congestive heart failure (CHF) in RA are controversial. The available published data suggest the following: (a) RA patients with history of CHF and a concomitant indication for the use of TNF-α blockers do not need a baseline cardiac evaluation to screen for heart failure; (b) patients with well-compensated mild CHF New York Heart Association (NYHA) classes I and II and a concomitant indication for the use of TNF-α blockers should be evaluated at baseline and then be closely monitored for any clinical signs of worsening heart failure; and (c) patients with (NYHA) class III or IV heart failure should not be treated with TNF-α blockers in any case.