Long-term mortality and cardiovascular risk stratification of peritoneal dialysis patients using a combination of inflammation and calcification markers

BACKGROUND: It remains unknown whether a composite of inflammation and calcification markers provides better mortality and cardiovascular risk stratification in chronic peritoneal dialysis (PD) patients. METHODS: We performed a 4-year prospective follow-up study in 231 chronic PD patients from a single regional dialysis centre in Hong Kong. Valvular calcification was detected using echocardiography, and fasting venous blood was collected to measure a panel of inflammation markers. The patients were stratified into five groups on the basis of 0, 1, 2, 3 and all 4 inflammation and calcification risk markers, namely high C-reactive protein (CRP) (CRP in upper tertile), high interleukin-6 (IL-6) (IL-6 in upper tertile), low fetuin-A (fetuin-A in lower tertile) and valvular calcification. Study outcomes included all-cause and cardiovascular mortality and fatal or non-fatal cardiovascular events (CVEs). RESULTS: The patients with 4, 3, 2 and 1 markers had an adjusted hazard ratio (HR) of 5.17 (95% CI, 1.81-14.77, P = 0.002), 3.38 (95% CI, 1.50-7.60; P = 0.003), 2.17 (95% CI, 0.98-4.77; P = 0.056) and 2.42 (95% CI, 1.18-4.96; P = 0.016), respectively, for mortality at 4 years than those with 0 risk marker. The adjusted HRs for fatal or non-fatal CVEs were 4.33 (95% CI, 1.70-11.03; P = 0.002), 1.60 (95% CI, 0.73-3.52; P = 0.24), 1.92 (95% CI, 0.95-3.90; P = 0.07) and 1.33 (95% CI, 0.67-2.62; P = 0.42), respectively, for patients with 4, 3, 2 and 1 markers than those with 0 risk markers. CONCLUSIONS: A composite of inflammation and calcification markers provides long-term prognostication and identifies the sickest PD patients with the worst clinical outcomes. Since these parameters can all be obtained quite readily, our data support the adoption of a multiinflammation and calcification risk marker approach for mortality and cardiovascular risk stratification in PD patients.