The PTH (1-84)/non-PTH (1-84) ratio is a risk factor for cardiovascular events in hemodialysis patients

Background: We hypothesized that the PTH (1-84)/non-PTH (1-84) ratio (PTH ratio) might help to assess cardiovascular risk in hemodialysis patients. Methods: In this prospective cohort study 70 prevalent hemodialysis patients were followed up to 4 years. The PTH ratio was determined at baseline. Primary outcomes were cardiovascular events (CVE) and all-cause mortality. Cumulative event-free survival was compared between patients with a ratio 1. The risk-association of the PTH ratio with CVE was examined using an adjusted Multiple Cox Proportional Hazards model. Results: A PTH ratio > 1 was found in 34 patients (49%). During follow-up 26 patients suffered a CVE. Patients with a CVE showed a higher ratio than patients with event-free survival (p = 0.033). In patients with a ratio > 1 a significantly higher number of CVE occurred (53 vs. 22%; p=0.013), and these patients showed a significantly shorter event-free survival (p = 0.032). In an adjusted Cox-proportional hazards model a higher PTH ratio was found to be independently associated with an elevated risk for CVE (HR = 3.2; 95% CI 1.06 - 13.63; p = 0.04). Conclusions: A higher PTH (1-84)/non-PTH (1-84) ratio is associated with an increased risk for CVE in hemodialysis patients and might therefore be useful for cardiovascular risk estimation in this population.