Cardiovascular risk factors underestimate atherosclerotic burden in chronic kidney disease: usefulness of non-invasive tests in cardiovascular assessment.

Background: Cardiovascular risk scoring (Score) does not specifically address chronic kidney disease (CKD) patients. The aim of our study is to quantify atherosclerosis using carotid ultrasound and ankle-brachial index (ABI) and to assess its additional value in risk scoring.

Methods: In this cross-sectional, observational study, patients were studied according to a standardized protocol including carotid ultrasound and ABI to determine the atherosclerosis score (AS), ranging from absence of to severe atherosclerosis (AS 0 to AS 3).

Results: We included 409 CKD-affected patients (231 on dialysis, 99 in CKD Stages IV-V and 79 in CKD Stages I-III) and 851 subjects with normal renal function. The presence and severity of atherosclerosis was significantly higher in the CKD group than in the controls at every decade of age studied. Among the CKD-affected subjects, the prevalence of carotid plaques was significantly higher in the dialysis group (78.3%) than in the group in CKD Stages I-III (55.6%, P < 0.001). We identified 174 patients at low-intermediate risk. Among them, 110 (63.2%) presented either moderate (AS 2) or severe (AS 3) atherosclerosis. Variables significantly (P < 0.05) and positively related to atherosclerosis were being on dialysis [OR = 3.40, 95% CI (1.73, 6.78) vs CKD Stages I-III], age [OR = 1.08, 95% CI (1.06-1.11)] and C-reactive protein [OR = 1.04, 95% CI (1.01-1.08)]. Conversely, female sex was negatively related to atherosclerosis [OR = 0.40, 95% CI (0.23-0.71), P = 0.002].

Conclusion: The use of carotid ultrasound and ABI identifies atherosclerosis in a population of CKD patients in which risk scoring underestimates atherosclerosis burden.