High iliac calcium score is associated with increased severity and complexity of peripheral arterial disease and predicts global atherosclerotic burden

The role of vascular calcifications in iliac arteries for predicting global atherosclerotic burden in still unknown. The aim of this study was to investigate whether iliac calcium score (ICS), a new computed tomographic angiography (CTA) derived biomarker of vascular calcification, can predict the severity and complexity of peripheral arterial disease (PAD) as well as the global atherosclerotic burden. This was a single centre, non-randomized, observational prospective study on 84 consecutive patients with symptomatic peripheral arterial disease, undergoing peripheral CTA examination of the lower limbs, divided into high (n = 42) and low ICS (n = 42) groups with a median value for ICS of 3934 HU. Patients with high ICS were significantly older (66.2 ± 8.0 vs. 62.8 ± 11.2, p < 0.0001) and were more frequently diabetic (61.9 vs. 38.1 %, p = 0.04). ICS was significantly higher in patients with Rutherford stage 5-6 vs. 1-2 (p = 0.03) and in TASC D or TASC C vs. TASC B class (p = 0.01). Mean iliac intima-media thickness (i-IMT) was significantly higher in the high ICS group compared to the low ICS group (1.3 ± 0.2 vs. 0.9 ± 0.2, p < 0.0001). Linear regression analysis demonstrated a very good correlation between ICS and i-IMT (r = 0.59, p < 0.0001 for right, r = 0.57, p < 0.0001 for left and r = 0.67, p < 0.0001 for both iliac arteries averaged). Patients with high ICS presented a significantly lower left ventricular ejection fraction compared to those with low ICS (45.3 ± 4.3 vs. 53.8 ± 4.8, p < 0.0001). Linear regression analysis demonstrated significant inverse correlation between ICS and left ventricular EF (r = -0.54, p < 0.0001). Increased values of ICS, a new CTA marker of vascular calcification, are associated with a higher severity and complexity of PAD and a more depressed left ventricular function. High ICS values are also associated with increased i-IMT. Both can represent new surrogate markers of an increased atherosclerotic burden.