Serum Calcification Propensity and Clinical Events in CKD

Background and objectivesPatients with CKD are at high risk for cardiovascular disease, ESKD, and mortality. Vascular calcification is one pathway through which cardiovascular disease risks are increased. We hypothesized that a novel measure of serum calcification propensity is associated with cardiovascular disease events, ESKD, and all-cause mortality among patients with CKD stages 2?4.Design, setting, participants, & measurementsAmong 3404 participants from the prospective, longitudinal Chronic Renal Insufficiency Cohort Study, we quantified calcification propensity as the transformation time (T-50) from primary to secondary calciprotein particles, with lower T-50 corresponding to higher calcification propensity. We used multivariable-adjusted Cox proportional hazards regression models to assess the associations of T-50 with risks of adjudicated atherosclerotic cardiovascular disease events (myocardial infarction, stroke, and peripheral artery disease), adjudicated heart failure, ESKD, and mortality.ResultsThe mean T-50 was 313 (SD 79) minutes. Over an average 7.1 (SD 3.1) years of follow-up, we observed 571 atherosclerotic cardiovascular disease events, 633 heart failure events, 887 ESKD events, and 924 deaths. With adjustment for traditional cardiovascular disease risk factors, lower T-50 was significantly associated with higher risk of atherosclerotic cardiovascular disease (hazard ratio [HR] per SD lower T-50, 1.14; 95% confidence interval [95% CI], 1.05 to 1.25), ESKD within 3 years from baseline (HR per SD lower T-50, 1.68; 95% CI, 1.52 to 1.86), and all-cause mortality (HR per SD lower T-50, 1.16; 95% CI, 1.09 to 1.24), but not heart failure (HR per SD lower T-50, 1.06; 95% CI, 0.97 to 1.15). After adjustment for eGFR and 24-hour urinary protein, T-50 was not associated with risks of atherosclerotic cardiovascular disease, ESKD, and mortality.ConclusionsAmong patients with CKD stages 2?4, higher serum calcification propensity is associated with atherosclerotic cardiovascular disease events, ESKD, and all-cause mortality, but this association was not independent of kidney function.