Cardiovascular Risk Stratification of Patients Undergoing Hematopoietic Stem Cell Transplantation: The CARE‐BMT Risk Score

Abstract

Background Evidence guiding the pre‐hematopoietic stem cell transplantation (HSCT) cardiovascular evaluation is limited. We sought to derive and validate a pre‐HSCT score for the cardiovascular risk stratification of HSCT candidates. Methods and Results We leveraged the CARE‐BMT (Cardiovascular Registry in Bone Marrow Transplantation) study, a contemporary multicenter observational study of adult patients who underwent autologous or allogeneic HSCT between 2008 and 2019 (N=2435; mean age at transplant of 55 years; 4.9% Black). We identified the subset of variables most predictive of post‐HSCT cardiovascular events, defined as a composite of cardiovascular death, myocardial infarction, heart failure, stroke, atrial fibrillation or flutter, and sustained ventricular tachycardia. We then developed a point‐based risk score using the hazard ratios obtained from Cox proportional hazards modeling. The score was externally validated in a separate cohort of 919 HSCT recipients (mean age at transplant 54 years; 20.4% Black). The risk score included age, transplant type, race, coronary artery disease, heart failure, peripheral artery disease, creatinine, triglycerides, and prior anthracycline dose. Risk scores were grouped as low‐, intermediate‐, and high‐risk, with the 5‐year cumulative incidence of cardiovascular events being 4.0%, 10.3%, and 22.4%, respectively. The area under the receiver operating curves for predicting cardiovascular events at 100 days, 5 and 10 years post‐HSCT were 0.65 (95% CI, 0.59–0.70), 0.73 (95% CI, 0.69–0.76), and 0.76 (95% CI, 0.69–0.81), respectively. The model performed equally well in autologous and allogeneic recipients, as well as in the validation cohort. Conclusions The CARE‐BMT risk score is easy to calculate and could help guide referrals of high‐risk HSCT recipients to cardiovascular specialists before transplant and guide long‐term monitoring.

Keywords

• atrial fibrillation
• bone marrow transplant
• cardiovascular disease
• heart failure
• hematopoietic stem cell transplant
• random forest