Associations of Mean Corpuscular Hemoglobin with Survival and Cardiovascular Outcomes Among Patients with Hemodialysis in Japan Based on Real-World Data

INTRODUCTION: Anemia in chronic kidney disease increases mortality risk in patients with hemodialysis. Hemoglobin (Hb) is currently used as the primary biomarker for renal anemia management. Recently, mean corpuscular hemoglobin (MCH) has gained attention as an indicator for improving anemia care. Using a large real-world dataset, we assessed the associations of MCH with survival and cardiovascular outcomes in Japanese patients with hemodialysis. METHODS: We conducted a retrospective cohort study of 8266 patients receiving maintenance hemodialysis, using a nationwide electronic medical record database (Sept 2004-Apr 2023). MCH at the index date was categorized into quintiles. We examined the associations of MCH with all-cause mortality and major adverse cardiovascular events (MACE)-plus (comprising death, myocardial infarction, stroke, heart failure hospitalization, thromboembolism) using Cox proportional hazards models and restricted cubic spline analyses. RESULTS: Over a median follow-up of 2.8 years, 1414 deaths (17.1%) and 3537 MACE-plus events (42.9%) occurred. Low MCH (< 28.1 pg) was independently associated with increased all-cause mortality (adjusted hazard ratio [HR] 1.287; 95% confidence interval [CI] 1.012-1.637), while only a non-significant trend was observed for MACE-plus (p = 0.074). Spline analyses revealed that both low and high MCH were associated with increased mortality and MACE-plus. In patients with Hb 10.0-12.0 g/dL, low MCH (< 28.1 pg) was significantly linked to higher mortality (adjusted HR 1.432; 95% CI 1.007-2.038). CONCLUSION: In Japanese patients with hemodialysis, both low and high MCH levels may provide information for predicting mortality and cardiovascular risk. Incorporating MCH alongside Hb may enhance risk stratification and improve anemia management.