Valvular calcifications at the start of dialysis predict the onset of cardiovascular events in the course of follow-up

Abstract

Valvular calcification (VC) in chronic kidney disease is frequent, although most information derives from prevalent dialysis patients. There are few studies that analyse VC in patients who start dialysis. Objective: To analyse the presence of VC at the start of dialysis and its relationship with events and/or death from cardiovascular causes in the course of follow-up. Methods: In the study, we included patients who started dialysis between November 2003 and September 2007. In the first month of treatment, we assessed the presence of VC by Doppler echocardiography, along with demographic factors and risk factors for cardiovascular disease, coronary artery disease, stroke, atrial fibrillation (AF), and cardiac dimensional and functional electrocardiographic and echocardiographic parameters. The biochemistry values assessed were: haemoglobin, calcium/phosphorous/iPTH metabolism, cholesterol and fractions, triglycerides, troponin I, albumin, CRP and glycosylated haemoglobin. We analysed the association between VC and the presence of myocardial infarction (MI), stroke and/or death from cardiovascular causes up to transplantation, death or the end of the study (December 2012). Results: Of 256 enrolled patients (83% haemodialysis, 17% peritoneal dialysis), 128 (50%) had VC (mitral: 39, aortic: 20, both: 69). In the multivariate analysis, VC was associated with older age (OR: 1.110; 95% CI: 1.073–1.148; p = 0.000) and lower albumin levels (OR: 0.29; 95% CI: 0.14–0.61; p = 0.001). In a follow-up lasting 42.1 ± 30.2 months (898.1 patient-years), 68 patients suffered MI, stroke and/or died from cardiovascular causes. In the Cox regression analysis, older age (HR: 1.028; 95% CI: 1.002–1.055; p = 0.037), coronary artery disease and/or stroke (HR: 1.979; 95% CI: 1.111–3.527; p = 0.021), AF (HR: 2.474; 95% CI: 1.331–4.602; p = 0.004), and the presence of VC at the start of dialysis (HR: 1.996; 95% CI: 1.077–3.700; p = 0.028) were the predictor variables for the occurrence of the analysed events. Conclusions: The prevalence of VC at the start of dialysis is high and its presence predicts the occurrence of events and/or cardiovascular death in the course of follow-up