Different Lower Extremity Arterial Calcification Patterns in Patients with Chronic Limb-Threatening Ischemia Compared with Asymptomatic Controls

Abstract

Objectives The most severe type of peripheral arterial disease (PAD) is critical limb ischaemia (CLI). In CLI, calcification of the vessel wall plays an important role in symptoms, amputation rate and mortality. However, calcified arteries are also found in asymptomatic persons (non-PAD patients). We investigated whether the calcification pattern in CLI patients and non- PAD patients are different and could possibly explain the symptoms in CLI patients. Materials and Methods 130 CLI and 204 non-PAD patients underwent a CT of the lower extremities. This resulted in 118 CLI patients (mean age 72±12, 70.3% male) that were age-matched with 118 non-PAD patients (mean age 71±11, 51.7% male). The characteristics severity, annularity, thickness and continuity were assessed in the femoral and crural arteries and analysed by binary multiple logistic regression. Results Nearly all CLI patients have calcifications and these are equally frequent in the femoropopliteal (98.3%) and crural arteries (97.5%), while the non-PAD patients had in just 67% any calcifications with more calcifications in the femoropopliteal (70.3%) than in the crural arteries (55.9%, p<0.005). The crural arteries of the CLI patients had significantly more complete annular calcifications (OR 2.92, p=0.001.) while in the non-PAD patients dot-like calcifications dominated. In CLI patients, the femoropopliteal arteries had more severe, irregular / patchy and thick calcifications (OR 2.40, 3.27, 1.81, p≤0.05, respectively) while in non-PAD patients, thin continuous calcifications prevailed. Conclusions Compared with non-PAD patients CLI patients are more frequently and extensively calcified. Annular calcifications were found in the crural arteries of CLI patients while dot-like calcifications were mostly present in the non-PAD patients. These different patterns of calcifications in CLI point at different etiology and can have prognostic and eventually therapeutic consequences.