Secondary calciprotein particle size is associated with patient mortality in peripheral artery disease

Background and aims: Secondary calciprotein particles (CPP-II) induce inflammation and contribute to vascular calcification. CPP-II size is associated with vascular calcification in patients with chronic kidney disease (CKD) and all-cause mortality in hemodialysis patients. Here, we investigate for the first time a possible role of CPP-II size in patients with peripheral artery disease (PAD) without severe CKD.Methods: We measured the hydrodynamic radius (Rh) of CPP-II by using dynamic light scattering in a cohort of 281 PAD patients. Mortality was evaluated over a period of ten years by central death registry queries. 35% of patients died during the observation period (median of 8.8 (6.2-9.0) years). Cox-regression analyses were per-formed to estimate hazard ratios (HR) and 95% confidence intervals (CI) and to allow for multivariable adjustment.Results: The mean CPP-II size was 188 (162-218) nm. Older patients, patients with reduced kidney function, and those with media sclerosis had larger CPP-II (p < 0.001, p = 0.008, andp = 0.043, retrospectively). There was no association between CPP-II size and overall atherosclerotic disease burden (p = 0.551). CPP-II size was inde-pendently significantly associated with all-cause (HR 1.33 (CI 1.01-1.74), p = 0.039) and cardiovascular mor-tality (HR 1.52 (CI 1.05-2.20), p = 0.026) in multivariable regression analyses.Conclusions: Large CPP-II size is associated with mortality in PAD patients and might be a new feasible biomarker for the presence of media sclerosis in this patient population.

Automated summary

This study investigates the association between the size of secondary calciprotein particles (CPP-II) and mortality in peripheral artery disease (PAD) patients. The results suggest that larger CPP-II size is significantly associated with all-cause and cardiovascular mortality in this patient population, indicating its potential as a new feasible biomarker for the presence of media sclerosis.