Novel cardiovascular risk prediction models in patients with systemic lupus erythematosus

Abstract

Women with systemic lupus erythematosus (SLE) have increased risk for coronary heart disease (CHD) which is underestimated by the Framingham risk score (FRS). We hypothesized that new risk scores that include inflammation or vascular age in the risk calculation would better identify women with SLE at risk for CHD, particularly in those with subclinical coronary atherosclerosis. We calculated the FRS and Reynolds risk score (RRS) in 121 women with SLE and 65 age-matched female controls; coronary age-modified risk scores (camFRS, camRRS) were calculated using coronary age derived from the coronary artery calcium (CAC) score. Risk scores were compared in SLE and controls, and in SLE patients with and without CAC. Although CAC was present in 21 SLE patients (17%) and four controls (6%) (p = 0.033); the FRS, camFRS, RRS, and camRRS, did not differ significantly among SLE and controls (p > 0.05), but were all significantly higher in SLE patients with CAC compared with those without (p < 0.001 for all). The camFRS (8%, p = 0.016) but not camRRS (5%, p = 0.221) assigned significantly more SLE patients to a category of ≥ 10% risk than conventional FRS (1%) and RRS (2%). The RRS was of limited use but coronary age may improve CHD risk prediction in SLE.

Figure 1. 10-year risk estimates (%) in women with SLE and age-matched controls

Subjects with coronary calcium are represented by red filled circles, and those without coronary calcium are represented by black empty circles. FRS= 10-year Framingham risk score; RRS: 10-year Reynolds risk score; camFRS: coronary age-modified FRS; cam-RRS: coronary age-modified RRS.

Figure 2. Relationship between chronological age and coronary age among controls and patients with SLE

Each line represents a single subject. Blue dotted lines represent subjects with a chronological age ≤ 39 years old who did not have coronary calcium and therefore chronological age = coronary age. Red dotted lines represent subjects with a chronologic age >39 years without coronary calcium. Solid lines represent subjects with coronary calcium; solid green lines represent those with chronological age < coronary age, and solid red lines those with chronological age ≥ coronary age.