Association between Lower Limb CT Calcification Score and Prognosis in Hemodialysis Patients

Abstract

We introduced a new index, termed the ʼlower limb CT calcification score,ʼ for patients undergoing hemodialysis. This score was calculated by measuring the sum (L) of the total lengths of the common iliac arteries, external iliac arteries, superficial femoral arteries, popliteal arteries, and posterior tibial arteries on plain CT. Additionally, we determined the sum (C) of calcification areas in both lower limbs from the same scans. The lower limb CT calcification score was defined as C÷L×100％. In the group of patients with peripheral artery disease (PAD), HDL cholesterol levels were low；blood glucose levels were high；ABI, SPP (plantar), PVR (ankle), and PVR (plantar) were low；and the lower limb CT calcification score was high. Lower limb CT calcification score showed a positive correlation with age, duration of dialysis, pulse pressure, coronary artery calcium score, carotid artery plaque score, and baPWV. On the other hand, it exhibited a negative correlation with HDL cholesterol levels, ABI, and PVR. In multiple regression analysis, significant independent variables for the lower limb CT calcification score were coronary artery calcium score, carotid artery plaque score, and ABI. Patients with a lower limb CT calcification score of 60％ or higher had lower survival rates compared to those with a score below 60％. Lower limb CT calcification score was identified as a significant variable in overall mortality using Cox proportional hazard analysis. Lower limb CT calcification score may be a useful indicator for predicting the progression of lower limb arterial calcification and prognosis in hemodialysis patients.