Karki, Dhan Bahadur

Abstract Rationale: Mechanical ventilation is frequently required in heart transplant patients to support recovery, but prolonged ventilation may increase the risk of complications and mortality. This study is done to find the impact of pre-transplant ventilation duration on early post-transplant outcomes, including mortality, ICU stay, infection, and respiratory complications. Methods: This retrospective analysis includes 52 heart transplant recipients from Mayo Clinic (2019-2023) who required pre-transplant mechanical ventilation. We analyzed ventilation duration's relationship with ICU and hospital stay, infection rates, respiratory complications, mortality, and baseline demographics. Chi-squared and Mann-Whitney U tests were used to evaluate associations between co-morbidities, ventilation duration, and outcomes. Results: The mean age at transplant was 48.9±14 years. Average ventilation duration was 12.8±14.2 days (Median: 7 days), ICU stay was 24.8± 20.9 days (Median: 15.0 days), and hospital stay was 58±40.8 days (Median: 48 days). Of the patients, 5 (9.6%) did not survive. There was no statistically significant association between mortality and ventilation duration, with a mean duration of 12.7±14.6 days (Median: 7 days) for survivors and 13.6±11.5 days (Median: 21 days) for non-survivors (p>0.05). Patients with infections 23 (44.2%) or respiratory complications 17 (32.7%) had longer ventilation durations (mean 16.3±17.8 days, Median: 9 and 10 days, respectively) compared to those without complications (mean 10±10.2 days, Median: 6 and 5 days, p>0.05). Infection was associated with extended ICU stays (mean 27.5±22.3 days, Median: 18 days with infection vs. 22.7±19.9 days, Median: 15 days without infection). None of the individual co-morbidities (diabetes, hypertension, stroke, chronic kidney disease) significantly impacted mortality or ventilation duration (p > 0.05). Conclusions: Prolonged ventilation is associated with increased rates of infections and respiratory complications but not with mortality in this cohort. Although co-morbidities did not significantly impact ventilation duration or mortality, infection remains a critical factor related to extended ICU stay. Future research should explore preventative strategies for infections in ventilated heart transplant recipients to improve outcomes.

Abstract Rationale: Early management after heart transplantation is essential for survival and quality of life, but we lack data on how initial clinical measures might predict patient outcomes. This study investigates whether early postoperative hemodynamic and clinical parameters can predict 1-year mortality and complications. Methods: We conducted a retrospective study of 550 heart transplant patients treated at the Mayo Clinic from 2019 to 2023. Demographic, hemodynamic, and clinical data, including Central Venous Pressure (CVP), Pulmonary Arterial Pressure (PAP), cardiac index, Pulmonary Artery Pulsatility Index (PaPi), blood pressure, heart rate, and Vasoactive-Inotropic Score (VIS), were collected. Key outcomes included 1-year mortality, Intensive Care Unit (ICU) and hospital stay durations, and complications such as respiratory issues and Acute Kidney Injury (AKI). Patients were divided into quartiles based on VIS scores to compare clinical outcomes. Logistic regression assessed how each parameter predicted 1-year mortality. Results: The patients’ mean age was 53.3±13.1 years, with 391 (71.1%) male and an average Body Mass Index (BMI) of 27.5±4.9. The median ICU stay was 9 days (Interquartile Range [IQR]: 4-22.8), and the median hospital stay was 35 days (IQR: 17-57.8). Within one year, 28 (5.1%) patients experienced mortality and ICU readmission occurred in 52 (9.5%) patients. Higher VIS quartiles were associated with worse outcomes. Logistic regression revealed three significant predictors of 1-year mortality: higher CVP (p=0.0305) and lower Systolic Blood Pressure (SBP) (p=0.0484) were linked to increased mortality risk, while each unit increase in VIS (p=0.0355) raised mortality odds by 6% (Odds Ratio [OR]: 1.06, 95% Confidence Interval [CI]: 1.004-1.113). Additionally, respiratory complications were seen in 177 (32.2%) patients, and AKI in 407 (74.0%) patients. AKI significantly predicted mortality (OR=2.50, p=0.044), while both ICU readmission (OR=2.98, p<0.001) and AKI (OR=3.49, p<0.001) predicted respiratory complications. Conclusions: Early postoperative hemodynamic and clinical parameters, especially higher VIS scores, are significant indicators of 1-year mortality in heart transplant patients. These findings highlight the importance of early assessment to identify high-risk patients and potentially guide post-transplant management strategies.

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.