Impact of hepatitis C on survival in dialysis patients: a link with cardiovascular mortality?

Recent evidence has been accumulated showing that anti-HCV-positive serologic status is significantly associated with lower survival in dialysis populations, but the mechanisms underlying this negative relationship are still unclear. The aim of this study was to conduct a systematic review of the published medical literature concerning the impact of hepatitis C virus (HCV) infection on all-cause and disease-specific mortality of patients on regular dialysis. The relative risk of all-cause, cardiovascular and liver disease-related mortality was regarded as the most reliable outcome end-point. Study-specific relative risks were weighted by the inverse of their variance to obtain fixed- and random effect pooled estimates for mortality with HCV across the published studies. We identified fourteen observational studies involving 145 608 unique patients on long-term dialysis. Pooling of study results demonstrated that anti-HCV antibody was an independent and significant risk factor for death in patients on maintenance dialysis. The summary estimate for adjusted relative risk (all-cause mortality) was 1.35 with a 95% confidence interval (CI) of 1.25-1.47. Stratified analysis showed that the adjusted RR for liver disease-related death was 3.82 (95% CI, 1.92; 7.61); heterogeneity statistics, R(i) = 0.58 (P-value by Q-test = 0.087). The adjusted RR for cardiovascular mortality was 1.26 (95% CI, 1.10; 1.45); no heterogeneity was found (NS). This meta-analysis of observational studies indicates that anti-HCV-positive patients on dialysis have an increased risk of either liver or cardiovascular disease-related mortality compared with anti-HCV-negative patients. Further studies are in progress to understand better the link between HCV and cardiovascular risk among patients on maintenance dialysis.