Long-term mortality in ICU patients with hematological malignancies: Impact of organ support duration and ICU length of stay

Background: Patients with hematological malignancies face unique challenges due to immunosuppression and treatment-related complications. This study aims to evaluate long-term survival probabilities for ICU patients with hematological malignancy as a function of length of stay in the ICU and organ support duration, compared to non-hematological ICU patients. Methods: In this retrospective multicenter cohort study, patients with hematological malignancies were matched with four controls based on APACHE IV scores and year of admission. Mortality at 1 year following ICU admission was assessed using landmark analyses, stratified by length-of-stay and organ support duration. Results: A total of 2.775 admissions were included (555 hematological malignancy and 2.220 matched controls). One-year mortality for patients with hematological malignancy (matched controls) with ICU length of stay of at least 1, 7 and 14 days was 64 % (43 %), 72 % (42 %), and 74 % (34 %). For those receiving 1, 7 and 14 days of renal replacement therapy 1-year mortality was 79 % (60 %), 79 % (52 %), and 85 % (55 %). For those receiving blood transfusion for 1, 7 and 14 days 1-year mortality was 74 % (47 %), 81 % (51 %), and 86 % (50 %). For those receiving triple organ support for 1,7 and 14 days 1-year mortality was 84 % (54 %), 84 % (51 %), and 94 % (56 %). Conclusions: One-year mortality among patients with hematological malignancy compared to matched controls was higher at the first day of admission and stayed higher for patients who remained in the ICU. The observed one-year mortality seemed to increase with initiation of prolonged renal replacement therapy, blood transfusion and combination of at least 3 organs supported, but not for the other forms of organ support.