Morbidity and mortality are not improved by preemptive ICU transfer of acute myeloid leukemia patients presenting a high risk of early complications

Abstract Background: Acute myeloid leukemia (AML) is associated with a high rate of life-threatening early complications. Patients presenting with hyperleukocytosis >50x10⁹/L and/or promyelocytic leukemia at the time of AML diagnosis can be considered at high risk of early complications (HReC) and thus at high risk of mortality. At our institution, we propose preemptive ICU admission to HReC patients. In so doing, our goal is to prevent complication occurrence, or, failing that, to provide rapid life-sustaining treatment (LST). In the present retrospective study, we sought to determine whether preemptive ICU admission improves survival for patients newly diagnosed with AML. Results: We analyzed a total study population of 634 patients within a ten-year period. Of that population, 24.7% (n=157) was admitted to the ICU, 20.5% (n=130) due to complications and 4.2% (n=27) preemptively. Delays to ICU admission were 12.9 hours, 7 days and 181 days for respectively the preemptive, early complications and late complications groups, p<0.001. The preemptive group showed significantly better survival at one month post ICU admission (66.7%) compared to the early (37.7%) and late (46.4%) complications groups, p=0.039. Furthermore, LST recourse in the ICU was significantly lower in the preemptive group (41% (n=11)) compared to the early (73% (n=56)) and late (73% (n=41)) complications groups, p<0.001. However, when considering survival at one-month post AML diagnosis, no significant differences were observed between patients admitted preemptively and those admitted following complications. Additionally, Cox regression identified preemptive ICU admission as a predictive factor for mortality at one month post AML diagnosis (hazard ratio 2.72, p<0.013). These contradictory data may be explained by selection and chronological biases when the analysis is limited to only ICU patients. Conclusion: Preemptive ICU admission does not improve survival for patients with AML. Suggested benefits for preemptive ICU admission may reflect analysis biases.