Background: Randomized trials found that use of erythropoiesis-stimulating agents to target normal hematocrit (Hct) levels (>39%) compared with 27%-34.5% increases cardiovascular risk and mortality among chronic kidney disease patients. However, the effects of the most widely used Hct target in the past 2 decades, 34.5%-39%, have never been examined.
Objective: To compare the effects of 2 Hct target strategies-30.0%-34.5% (low) and 34.5%-39.0% (mid) in a high-risk population: elderly dialysis patients with significant comorbidities.
Research design: Observational data from the US Renal Data System were used to emulate a randomized trial in which patients were assigned to either Hct strategy. Follow-up started after completing 3 months of hemodialysis and ended 6 months later. We conducted the observational analogs of intention-to-treat and per-protocol analyses. Inverse-probability weighting was used to adjust for measured time-dependent confounding by indication.
Subjects: A total of 22,474 elderly patients with both diabetes and cardiovascular disease who initiated hemodialysis in 2006-2008.
Measures: Hazard ratios (HRs) and survival probabilities for all-cause mortality and a composite cardiovascular and mortality endpoint.
Results: The intention-to-treat HR (95% confidence interval) for mid versus low Hct strategy was 1.05 (0.99-1.11) for all-cause mortality and 1.03 (0.98-1.08) for the composite endpoint. The per-protocol HR (95% confidence interval) for mid versus low Hct strategy was 0.98 (0.78-1.24) for all-cause mortality and 1.00 (0.81-1.24) for the composite outcome.
Conclusions: Among hemodialysis patients, we did not find differences in 6-month survival or cardiovascular risk between clinical strategies that target Hct at 30.0%-34.5% versus 34.5%-39.0%.