Trends and race-sex disparities in in-hospital mortality of chemotherapy-induced cardiomyopathy in hematologic malignancies

Abstract Background: Chemotherapy-induced cardiomyopathy (CIC) is a serious, and often irreversible complication in patients treated for hematologic malignancies. While therapies for hematologic malignancies continue to evolve, data on trends in in-hospital mortality among patients with concurrent hematologic malignancies and CIC are limited, and disparities by race and sex remain poorly characterized. This study examines national trends and demographic disparities in in-hospital mortality among patients with hematologic malignancies who developed CIC. Methods: The United States (U.S) National Inpatient Sample (NIS) from 2016 to 2020 was queried for patients diagnosed with malignant hematologic and lymphoid neoplasms who also developed CIC. Hematologic malignancies were identified using ICD-10 codes C81–C96, which include: C81 for Hodgkin lymphoma; C82–C86 for non-Hodgkin lymphomas; C88 for malignant immunoproliferative diseases (e.g., Waldenström macroglobulinemia, heavy chain disease); C90–C95 for leukemias of lymphoid, myeloid, monocytic, mixed, and unspecified cell types; and C96 for other or unspecified malignant neoplasms of lymphoid, hematopoietic, and related tissue. CIC was identified using ICD-10 code I42.7. The study was exempt from institutional review board approval as the NIS database contains deidentified patient information. Multivariable regression analysis was performed to determine the odds of in-hospital mortality among patients with hematologic malignancies who developed CIC. Multivariable logistic regression followed by marginal effects was used to plot yearly trends in in-hospital mortality. All the outcomes were adjusted for gender, race, Charlson comorbidity index and hospital characteristics. P < 0.05 was used to determine statistical significance. The analysis was performed on STATA 16 software. Results: The study identified a total of 3,021,434 hospitalizations with hematologic malignancies, of which 11,115 (0.004%) had secondary diagnosis of CIC (mean age = 56.5 years, 52.5% males). Among 11,115 patients with hematologic malignancies who developed CIC, 740 (6.6%) patients died during the hospitalization. Multivariable logistic regression followed by marginal effects estimated a decrease in adjusted in-hospital mortality trend from 6.5% in 2016 to 4.3% in 2020. However, this decreasing mortality trend was not statistically significant after adjusting for gender, race, Charlson comorbidity index, and hospital characteristics (OR: 0.93; 95% CI: 0.83 – 1.05; trend p = 0.260). In-hospital mortality did not differ significantly between male vs. female patients with hematologic malignancies who developed CIC (OR: 1.02; 95% CI: 0.72 – 1.43; p = 0.921). There was no difference in overall in-hospital mortality of patients of White (reference) vs. Black (OR: 1.12; 95% CI: 0.72 – 1.76, p = 0.61) or Hispanic (OR: 0.63; 95% CI: 0.32 – 1.25, p = 0.18) race. However, males of the Black race demonstrated a lower in-hospital mortality vs. males of the White race (OR: 0.26; 95% CI: 0.09 – 0.77, p = 0.01). In addition, females of the Black race showed a higher in-hospital mortality vs. females of the White race (OR: 2.43; 95% CI: 1.40 – 4.25, p <0.01). Conclusions: In patients with hematologic malignancies who developed CIC, overall in-hospital mortality did not differ significantly by race alone. However, on sex-based stratification, Black males had lower in-hospital mortality compared to White males, while Black females had higher mortality than White females. These differences highlight potential race–sex disparities in outcomes that warrant further investigation.