In the United States, there are two main methods for estimating CV risk, the Framingham Risk Score and the Reynold’s Risk Score.4,5 The Framingham Risk Score, the most established of the two, incorporates risk factors such as total cholesterol levels and blood pressure to estimate the 10-year risk for a coronary event. The Reynold’s Risk Score also includes traditional risk factors but takes into account inflammation with the addition of high-sensitivity C-reactive protein (hsCRP).
Neither method is believed to accurately estimate the risk of heart disease in RA, but both are good starting points. The Framingham Risk Score likely underestimates risk by approximately 50%, largely because inflammation is not taken into account.6 The European League Against Rheumatism published their recommendation on estimating CV risk in RA by multiplying a patient’s Framingham Risk Score by 1.5 if a patient has two or more of the following: disease duration greater than 10 years, rheumatoid factor or anticyclic citrullinated peptide antibody positivity, or the presence of extraarticular manifestations.6 This multiplier was developed as a result of evidence-based expert opinion but has not been validated.
The Reynold’s Risk Score, which does incorporate inflammation as a risk factor, includes hsCRP as a risk factor. One of the main issues with applying the Reynold’s risk score to RA patients is that the population where the risk score was developed had a mean hsCRP of 2.0mg/L. In the Brigham Rheumatoid Arthritis Sequential Study, a prospective cohort of approximately 1,100 treated RA patients, the mean CRP was 9.7mg/L, which is consistent with other established RA cohorts and is well above the range of hsCRP levels for which the Reynold’s Risk Score was calibrated.7
Preventing Heart Disease
“All the same,” said the Scarecrow, “I shall ask for brains instead of a heart; for a fool would not know what to do with a heart if he had one.”
Fortunately, we have much guidance about how to prevent heart disease in RA based on the wealth of studies in the general population. The first, and perhaps the hardest, intervention is a change in habit: eating a well-balanced diet, exercising on a regular basis, and maintaining a healthy weight. We all know how well that works. Additionally, prevention can be achieved with treatment intervention of the risk factors for heart disease such as angiotensin-converting enzyme inhibitors, statins, and, in some patients, metformin. We also have targets to aim for based on a patient’s risk profile, such as blood-pressure goals (Joint National Committee VII), LDL levels (Adult Treatment Panel III Guidelines), and hemoglobin A1C.
