Cardiopulmonary Exercise Test With Comorbidity Index Before Allogeneic Hematopoietic Stem Cell Transplantation

Abstract

Purpose: To evaluate the role of the cardiopulmonary exercise test (CPET) with comorbidity index as a predictor of overall survival (OS) and non-relapse mortality (NRM) in patients with hematological malignancies who undergo allogeneic hematopoietic stem cell transplantation (HSCT).

Methods: We retrospectively analyzed consecutive adult patients with hematological malignancies who underwent HLA-matched donor-HSCT at Chungnam National University Hospital (Daejeon, South Korea) between January 2014 and December 2020. Maximal oxygen consumption (VO₂max) was classified using the recommendations of the Mayo Clinic database.

Results: Of 72 patients, 38 (52.8%) had VO₂max values lower than the 25th percentile (VO_2max ≤ 25^th) of an age- and sex-matched normal population. Patients with VO₂max ≤ 25^th had no significant differences both OS and NRM (30 month OS 29.8% vs 41%, P = .328; and 30 month NRM 16% vs 3.3%, P = .222), compared with other patients. VO₂max ≤ 25^th was assigned a weight of 1 when added to the Hematopoietic Cell Transplantation-specific Comorbidity Index (HCT-CI) to form a composite comorbidity/CPET index (HCT-CI/CPET). Patients with HCT-CI/CPET scores of 0 to 1 demonstrated significantly better OS and NRM than did patients with HCT-CI/CPET scores ≥2 [median OS not reached vs 6 months, P < .001 and 30 month NRM 7.4% vs 33.3%, P = .006]. An HCT-CI/CPET score ≥2 was the only adverse risk factor for NRM on multivariate analysis [hazard ratio (HR) of NRM 10.36 (95% CI 1.486-2.25, P = .018)].

Conclusion: The composite HCT-CI/CPET score can predict the survival and mortality of patients with hematological malignancies who undergo allogeneic HSCT.

Keywords: allogeneic hematopoietic stem cell transplantation; cardiopulmonary exercise test; comorbidity index; non-relapse mortality; overall survival.