Mortality reduction by post-dilution online-haemodiafiltration: a cause-specific analysis

WOS: 000398117600023PubMed ID: 28025382Background. From an individual participant data (IPD) meta-analysis from four randomized controlled trials comparing haemodialysis (HD) with post-dilution online-haemodiafiltration (ol-HDF), previously it appeared that HDF decreases all-cause mortality by 14% (95% confidence interval 25; 1) and fatal cardiovascular disease (CVD) by 23% (39; 3). Significant differences were not found for fatal infections and sudden death. So far, it is unclear, however, whether the reduced mortality risk of HDF is only due to a decrease in CVD events and if so, which CVD in particular is prevented, if compared with HD. Methods. The IPD base was used for the present study. Hazard ratios and 95% confidence intervals for cause-specific mortality overall and in thirds of the convection volume were calculated using the Cox proportional hazard regression models. Annualized mortality and numbers needed to treat (NNT) were calculated as well. Results. Besides 554 patients dying from CVD, fatal infections and sudden death, 215 participants died from 'other causes', such as withdrawal from treatment and malignancies. In this group, the mortality risk was comparable between HD and ol-HDF patients, both overall and in thirds of the convection volume. Subdivision of CVD mortality in fatal cardiac, non-cardiac and unclassified CVD showed that ol-HDF was only associated with a lower risk of cardiac casualties [0.64 (0.61; 0.90)]. Annual mortality rates also suggest that the reduction in CVD death is mainly due to a decrease in cardiac fatalities, including both ischaemic heart disease and congestion. Overall, 32 and 75 patients, respectively, need to be treated by high-volume HDF (HV-HDF) to prevent one all-cause and one CVD death, respectively, per year. Conclusion. The beneficial effect of ol-HDF on all-cause and CVD mortality appears to be mainly due to a reduction in fatal cardiac events, including ischaemic heart disease as well as congestion. In HV-HDF, the NNT to prevent one CVD death is 75 per year.EuDial working group; European Nephrology and Dialysis Institute; Catalan Society of Nephrology; Fresenius Medical Care; Dutch Kidney Foundation [C02.2019]; Fresenius Medical Care, Netherlands; Gambro Lundia AB, Sweden; Dr E.E. Twiss Fund; International Society of Nephrology/Baxter Extramural Grant Program; Netherlands Organization for Health Research and DevelopmentNetherlands Organization for Health Research and Development [170882802]; national grant from the Health Ministry (Programme Hospitalier de Recherche Clinique, PHRC); Gambro through the Catalan Society of Nephrology; Roche NetherlandsThe HDF Pooling project was designed, conducted and analysed independently of the financial contributors of the individual studies as listed below. Study data were collected and retained by the investigators and were not available for the financial contributors of the individual studies. S.A.E.P. and the meetings of the representatives of the combined authors of the four studies were financially supported by the EuDial working group. EuDial is an official working group of the European Renal Association-European Dialysis Transplant Association (ERA-EDTA, http://era-edta.org/eudial/European_Dialysis_Working_Group.html). No industry funding was received for any part of or activity related to the present analysis.; The Turkish HDF study was supported by European Nephrology and Dialysis Institute with an unrestricted grant. The study was performed in Fresenius Medical Care haemodialysis clinics in Turkey. ESHOL was supported by The Catalan Society of Nephrology and by grants from Fresenius Medical Care and Gambro through the Catalan Society of Nephrology. The CONTRAST study was supported by a grant from the Dutch Kidney Foundation (Nierstichting Nederland Grant C02.2019), and unrestricted grants from Fresenius Medical Care, Netherlands, and Gambro Lundia AB, Sweden. Additional support was received from the Dr E.E. Twiss Fund, Roche Netherlands, the International Society of Nephrology/Baxter Extramural Grant Program, and the Netherlands Organization for Health Research and Development (ZONMw Grant 170882802). The French HDF study was supported by a national grant from the Health Ministry (Programme Hospitalier de Recherche Clinique, PHRC) as a means to improve care and outcome of elderly chronic disease patients