Abstract Body (Do not enter title and authors here):
Introduction: Hematopoietic stem cell transplantation (HSCT) is associated with adverse cardiovascular (CV) events including the development of heart failure (HF) and arrythmias. While transthoracic echocardiogram (TTE) is routinely obtained prior to HSCT, its role in predicting the incidence of HSCT related CV events is poorly understood.

Methods: We used data from the Cardiovascular Registry in Bone Marrow Transplantation (CARE-BMT) study, a multicenter observational study of adult patients (aged ≥18 years) who underwent autologous/allogeneic HSCT for malignant or nonmalignant bone marrow disorders at the University of Michigan Health System (UMHS) and Rush University Medical Center from 2008-2019. In this analysis, we included patients from UMHS with a baseline TTE. Data on pre-HSCT TTE parameters and post-HSCT CV outcomes were collected through manual chart review. Left ventricular (LV) function and dimensions were categorized into normal, mildly abnormal, and moderately/severely abnormal based on American Society of Echocardiography guidelines. The primary outcomes were new-onset HF and atrial fibrillation/flutter post-HSCT. Analyses were conducted using a Fine-Gray model adjusted for the pre-HSCT CARE-BMT CV risk score.

Results: Of the 2071 patients (mean age at HSCT 55.5+12.9 years; 59.5% male) with a pre-HSCT TTE (median 25 days pre-HSCT), 116 (5.6%) and 128 (6.2%) patients experienced HF and atrial fibrillation/flutter, respectively, over a median period of 2.2 years. Greater abnormalities in left ventricular internal diameter at end-diastole (LVIDd) and end-systole (LVIDs) were linearly associated with a higher risk of HF (P-trend 0.018 and 0.004, respectively) (Table). Similarly, moderately/severely abnormal LVIDd was associated with a 2.41-fold (95% CI: 1.07, 5.43) increase in risk of atrial fibrillation/flutter (Table). Pre-HSCT ejection fraction (EF) was not associated with either endpoint.

Conclusion: LV dilation, even when mild, was notably associated with increased risk of developing new HF or atrial arrythmias post-HSCT, regardless of EF. Whether evidence of LV dilation should prompt the initiation of guideline directed medical therapy to minimize the risk of incident HF warrants further study.