Karki, D.

Abstract Rationale: Mechanical circulatory support (MCS) devices, including Extracorporeal Membrane Oxygenation (ECMO) and Impella are essential in managing complex heart transplant cases. Identifying predictors for MCS utilization can improve patient selection and perioperative planning. This study aims to refine MCS allocation by analyzing pre-transplant predictors for each device, thereby optimizing clinical decision-making in critical care. Methods: This retrospective study included 594 heart transplant patients from 2019-2024 (mean age: 63 ± 1.41 years, 29% female, mean left ventricular ejection fraction (LVEF): 36.5 ± 33.23%, mean body mass index (BMI): 32.23 ± 4.497 kg/m²). Variables assessed included age, gender, BMI, smoking status, comorbidities (e.g., chronic kidney disease, hypertension, diabetes), heart failure etiology, and hemodynamic parameters (cardiac index, LVEF, PAPi). Multivariate logistic regression models estimated odds ratios (OR) and 95% confidence intervals (CI) for the likelihood of ECMO and Impella use based on pre-transplant variables. Results: 1. ECMO Use: ECMO was significantly associated with younger age (<40 years), elevated pulmonary artery pressure (PAPi <1.5; OR = 2.70, 95% CI: 1.13-6.48), and reduced cardiac index (<2.2 L/min/m²; OR = 3.12, 95% CI: 1.50-6.49). Male patients also had a higher likelihood of ECMO requirement (OR = 0.54, 95% CI: 0.29-1.00). These findings suggest ECMO may be required for younger, hemodynamically compromised patients. 2. Impella Use: Impella use was significantly associated with smoking history (OR = 3.72, 95% CI: 1.71-8.58), hypertension (OR = 2.08, 95% CI: 1.02-4.43), and low baseline LVEF (<25%; OR = 2.20, 95% CI: 1.18-4.07). Patients with chronic kidney disease or diabetes also had increased odds of requiring Impella, indicating its relevance for high-risk patients with vascular or metabolic burdens. Conclusions: This study identifies distinct pre-transplant predictors that influence MCS allocation in heart transplant patients. ECMO is associated with younger age and lower cardiac index, while Impella is more likely to be used in patients with vascular or metabolic comorbidities. These insights can enhance precision in MCS allocation, supporting optimal outcomes in critical care management.