Association of Cardiac Valvular Calcifications and C-Reactive Protein With Cardiovascular Mortality in Incident Hemodialysis Patients: A Japanese Cohort Study

Background: Cardiac valve calcification is seen frequently in patients undergoing dialysis. Serum C-reactive protein (CRP) level also is reported to predict future cardiovascular events. We investigated the association among valve calcification, CRP level, and mortality in patients with end-stage renal disease who were just beginning hemodialysis (HD) therapy. Study Design: Observational cohort. Setting & Participants: 1,290 consecutive patients who just started HD therapy were enrolled and were followed up to 10 years. Predictor: Patients were divided into 3 groups according to number of calcified valves: those without valve calcification, those with calcification in a single (aortic or mitral) valve, and those with calcification in both valves. They also were divided into tertiles according to CRP level. Outcomes: Cardiovascular and all-cause mortality. Measurements: Echocardiography and CRP measurement were performed within 1 month after beginning HD therapy. Results: During follow-up (median, 51 months), 335 (25.9%) patients died, including 156 (12.1%) of cardiovascular disease. The adjusted HR for cardiovascular mortality was 2.80 (95% CI, 1.63-4.81) for 2 calcifications versus 0 (P < 0.001). Furthermore, the risk of cardiovascular mortality was 3.66-fold higher in patients with calcifications in both valves (highest tertile of CRP) compared with patients without valve calcification (lowest tertile of CRP; P < 0.001). Limitations: Precise medical treatments or therapeutic interventions were not evaluated. Conclusions: Valve calcification and elevated CRP levels were not only related to additively increased risk of mortality, but also improved the prediction of mortality in patients with end-stage renal disease who had just begun HD therapy. Am J Kidney Dis. 61(2):254-261. (c) 2013 by the National Kidney Foundation, Inc.