"We believe that inflammation is a strong risk factor for cardiovascular disease," says the study's lead researcher.
While the experts are still unsure of exactly why rheumatoid arthritis's inflammation of large joints may lead to heart attack deaths, they say that issue is under investigation. In the meantime, they say, it's apparent that, keeping a patient's heart attack risk factor to its minimum is a matter of keeping inflammation to its minimum, too.
Mayo Clinic epidemiologists have found that the systemic inflammation characterizing rheumatoid arthritis may be to blame for the increased risk of cardiovascular death in patients with the disease.
"We believe that inflammation is a strong risk factor for cardiovascular disease among rheumatoid arthritis patients," says Hilal Maradit Kremers, M.D., lead study investigator and research associate in the Mayo Clinic Department of Health Sciences Research.
Rheumatoid arthritis patients have a significantly increased risk of dying of a heart condition if they have swelling in the large joints, rheumatoid vasculitis (inflammation of the blood vessels), rheumatoid lung disease or a high erythrocyte sedimentation rate (a blood test commonly known as ESR that measures level of inflammation in the body), report the investigators in the March issue of Arthritis & Rheumatism (http://www.rheumatology.org/publications/ar).
The exact means by which the inflammation in rheumatoid arthritis can lead to heart disease is unclear, say the Mayo Clinic investigators, who indicate this is currently under study.
The investigators hypothesize that if the degree of a rheumatoid arthritis patient's inflammation can be closely monitored and kept under strict control, the risk of death by heart condition may decrease.
The study was conducted using the resources of the Rochester Epidemiology Project (http://mayoresearch.mayo.edu/mayo/research/rep).
The researchers collected detailed information about all study subjects' cardiac events and their cardiovascular risk factors, such as diabetes, blood pressure, cholesterol, body mass index and smoking.
They also collected information on indicators of systemic inflammation and rheumatoid arthritis disease severity, such as rheumatoid factor positivity, ESR, joint swelling, radiographic changes, rheumatoid arthritis nodules, rheumatoid arthritis complications, rheumatoid arthritis treatments and disease duration.
In addition, the researchers collected information on comorbitities, the presence of additional diseases.