MUNICH — The mortality risk during a hospital stay for acute MI in patients with rheumatoid arthritis is as high as in those with diabetes, Gurkipal Singh, M.D., reported at the annual congress of the European Society of Cardiology.
The high-risk nature of acute coronary syndrome in diabetic patients has come to be broadly appreciated by the medical community during the last decade, but the evidence suggests that the same isn't true regarding coronary events in rheumatoid arthritis patients. This needs to change, said Dr. Singh of Stanford (Calif.) University.
“Patients with rheumatoid arthritis presenting with chest pain and probable MI should be stratified as high-risk, like diabetic patients, triaged accordingly, and managed aggressively,” the physician said.
Dr. Singh reviewed trends in acute MI survival among patients with rheumatoid arthritis as compared with diabetes in the National Inpatient Sample for 1991–2001.The National Inpatient Sample is a stratified random sample of U.S. hospital admissions. It is the only large American database on inpatient care, regardless of insurance coverage.
In 1991, 4% of all hospital admissions in patients with diabetes mellitus had a primary admitting diagnosis of acute MI, as was the case for 1.5% of all admissions involving patients with rheumatoid arthritis.
In-hospital mortality occurred in 11% of diabetic MI patients in 1991. The case fatality rate dropped to 7.7% by 2001, presumably because of new major therapeutic innovations—and a willingness to employ them aggressively in diabetic patients as the heavy toll cardiovascular disease takes in this population became better understood.
In contrast, in-hospital mortality after acute MI in rheumatoid arthritis patients during 1991–2001 slipped downward by a mere 0.03% per year. In 1991, rheumatoid arthritis patients with acute MI were 30% less likely than diabetic patients to die in-hospital, but by 2001 this survival advantage had disappeared: Their in-hospital mortality was 7.6%, compared with 7.7% in diabetic patients with MI.
The explanation for the relatively high acute MI fatality rate in rheumatoid arthritis patients isn't as clear as in diabetes. In 2001, rheumatoid arthritis patients with acute MI were older and much more likely to be female but less likely to have hypertension than diabetic patients hospitalized for an acute MI.
It is increasingly clear, however, that rheumatoid arthritis is a systemic inflammatory disease. The inflammatory process might encourage more extensive atheromatous plaque formation and hence larger infarct size than in nonarthritic individuals who develop acute MI, he said.