Pham, Si M.

Extracorporeal membrane oxygenation (ECMO) use during liver transplantation is a complex and evolving aspect of critical care. This retrospective analysis presents the largest North American case series to date, offering a detailed comparison of survival outcomes in liver transplant (LT) patients supported by ECMO. A total of 15 patients were supported with ECMO, eight were supported on venoarterial (VA) ECMO and the remaining seven on venovenous (VV) ECMO. The median duration of ECMO support was 10 days. Mean intensive care unit (ICU) and hospital stays were 34.8 (interquartile range [IQR]: 1–158) and 49.2 days (IQR: 1–121), respectively. Overall survival was 33.3%, comparable to published rates (20–30%). Survival was based on ECMO initiation timing: preoperative 33.3% (1/3); intraoperative 50% (3/6); postoperative, 16.6% (1/6). All the patients (five) discharged from hospital were alive at 1 year follow-up. Significant ECMO-related complications included acute kidney injury (AKI) requiring continuous renal replacement therapy (CRRT) (40%, n = 6/15), neurological complications (40%, n = 6/15), and bleeding requiring transfusion (26.6%, n = 4/15). Literature review suggests better outcomes with intraoperative or postoperative ECMO. While ECMO use is increasing in LT, outcomes remain poor. Improved survival may depend on careful patient selection, optimal timing of initiation, and distinguishing reversible pathology from irreversible one.

Background: Progressive heart failure cardiogenic shock (HFCS) often requires escalation to temporary or durable mechanical circulatory support (MCS) as a bridge to transplant (BTT). Following the 2018 UNOS allocation changes, our center revised its BTT strategy to optimize support and shorten wait times. At our institution, the Impella 5.5 with SmartAssist via the axillary approach was selectively used for patients who remained refractory to guideline-directed medical therapy, failed single-inotrope therapy, and were not considered suitable durable LVAD candidates by our multidisciplinary heart team. We compared transplant-related outcomes of BTT patients supported with Impella 5.5 versus durable LVAD. Methods: We performed a single-center retrospective review of all heart and heart/kidney transplant candidates at Mayo Clinic Florida from October 2018 to February 2021. INTERMACS profile, baseline characteristics, and perioperative data were collected at the time of device implantation and throughout the transplant hospitalization. Results: A total of 87 heart and 4 heart–kidney transplants were completed. Forty-five patients (49%) required MCS as BTT: 27 (60%) with a durable LVAD and 18 (40%) with an Impella 5.5. All eighteen patients with Impella 5.5 as BTT (100%) were transplanted compared to nineteen patients with durable LVAD (70%), p = 0.001. The median time from listing to transplant was substantially shorter with Impella (32 vs. 696 days, p < 0.001), and this difference persisted across INTERMACS profiles. UNOS status at transplant was more urgent for Impella than LVAD (p < 0.001). Transplant surgery following Impella support required shorter cardiopulmonary bypass time (181 vs. 219 min, p < 0.001) and resulted in lower postoperative vasoactive-inotropic requirements (7.9 vs. 13, p = 0.003). No patients in the Impella group died or were delisted while awaiting transplant, whereas 5 LVAD patients (26%) died or were removed due to LVAD complications (p < 0.001). Conclusions: Our data demonstrates that the use of the Impella 5.5 as BTT was associated with significantly shorter waitlist time, higher transplantation rates, reduced perioperative morbidity, and lower postoperative vasoactive support compared with durable LVAD as BTT. These benefits were achieved despite a higher severity of illness at transplantation in the Impella cohort.

Abstract Background Patients with end-stage heart failure and chronic kidney disease requiring dual-organ transplantation (DOT) face significant challenges in utilizing durable mechanical circulatory support due to the risks associated with renal replacement therapies (RRTs) and multi-organ failure. Given the limited options available for long-term support in this patient population, there remains a critical need for alternative strategies to optimize end-organ function and bridge patients safely to transplant. With prolonged waitlist times for DOT, we present our experience with the Impella 5.5 as temporary mechanical circulatory support, demonstrating its potential to provide hemodynamic stability and support as a bridge to transplantation (BTT) in this complex cohort. Methods A single-centre retrospective review was completed of all patients listed for single-organ transplantation or DOT between December 2019 and November 2022 at Mayo Clinic in Florida, supported by the Impella 5.5 intended as BTT. The focus of this analysis was patients requiring RRT or listed for heart/kidney transplantation. Data were extracted from the electronic health record at baseline and during their transplant episode of care after institutional review board approval as exempt status for retrospective data collection. Results A total of 41 patients were supported with Impella 5.5, intended as BTT. All patients underwent successful transplantation. We focus on the 10 patients with Impella support who underwent DOT. In the DOT group, the median age at transplantation was 63 years (59–66), with nine males and one female. The baseline median ejection fraction was 19% (15–22), with 50% Caucasian and 50% African American and an even split between ischaemic and non-ischaemic aetiology. Median body mass index was 30 kg/m2 (26–31), and 60% were in blood group O. The median time on the waitlist for DOT patients was 53 days (29–75). Perioperative management of DOT Impella patients demonstrated baseline haemodynamics of RA 11 mmHg (7–16), mean PA 36 mmHg (32–47), PCWP 29 mmHg (21–35), mixed venous saturation (SVO2%) 51 (46–61) and Fick CI 2.03 L/min/m2 (1.66–2.5). Post-Impella placement haemodynamics demonstrated significant improvements in RA pressure to 5 mmHg (4–8), P = 0.02, SVO2 to 70% (65–72), P = 0.002, and Fick CI to 5.5 (5.2–8), P = 0.03. The average duration of support was 44 days (range 10–94). The median glomerular filtration rate at baseline was 27 mmol/L (16–29). Twenty-four hour urine protein averaged 168 mg/24 h (range 87–328), with the 24 h creatinine clearance of 29 mg/24 h (range 24–35). Eight of the 10 patients required continuous or intermittent RRT before DOT. The median total duration of RRT (including Impella support) was 36 days (9–72). DOT recipients had a 1 year survival of 90%, with an average follow-up of 432 days. Conclusions Our findings demonstrate that prolonged use of the Impella 5.5 provides safe and effective haemodynamic support for patients with end-stage heart and kidney failure awaiting dual-organ transplantation. With a 1 year survival rate of 90%, our data suggest that Impella 5.5 can be a viable alternative to traditional support strategies, particularly in patients who are otherwise limited by RRTs. As dual-organ transplantation becomes more prevalent, the Impella 5.5 offers a promising bridge to transplant, improving both short-term and long-term outcomes in this complex patient population.

Heart transplantation is a well-established treatment for end-stage heart failure, but many patients present in poor physical condition, complicating outcomes. The Impella 5.5 device, used in cardiogenic shock, may support pretransplant rehabilitation by stabilizing organ function and promoting functional improvement. This retrospective cohort study assessed the relationship between functional status, measured by standardized Activity Measure for Post-Acute Care Basic Mobility (AM-PAC) scores, and days alive outside the hospital within 30 days post-transplant (DAOH-30). Patients who received Impella 5.5 support before transplantation between January 2019 and October 2023 were included, excluding those without AM-PAC scores within 24 hours pretransplant. Among 65 patients, the median DAOH-30 was 15 days (interquartile range [IQR], 8–19). Higher pretransplant standardized AM-PAC scores correlate with increased DAOH-30 (adjusted coefficient 0.3; 95% confidence interval [CI] = 0.01–0.6; p = 0.04), as did AM-PAC score improvement during rehabilitation (adjusted coefficient 0.35; 95% CI = 0.01–0.6; p = 0.04). Extended rehabilitation was associated with greater functional gains. These findings suggest that better pretransplant functional status and rehabilitation-related improvements were associated with increased DAOH-30. The Impella 5.5 device facilitates rehabilitation and may enhance post-transplant outcomes. Further research should refine strategies to optimize rehabilitation and recovery in this high-risk population.

Introduction/Background: Patients with heart failure and those waiting for a heart transplant often experience a significant decrease in their ability to perform daily activities and exercise, leading to a lower quality of life. Although exercise-based cardiac rehabilitation (EBCR) is a possible treatment option, its effectiveness has not been well measured, resulting in limited adoption. Research Questions/Hypothesis: Could physical rehabilitation before receiving a heart transplant improve functional status and better outcomes? Goals/Aims: Our objective is to evaluate the effect of pre-transplant physical therapy on the standardized improvement of AM-PAC scores, measured from the earliest pre-transplant assessment to the most recent pre-transplant evaluation. Our second objective is to assess the impact of the latest Pre-Transplant AM-PAC Score on the number of hospital-free days following transplantation. Methods: We conducted a retrospective study on 91 heart transplant patients who received Impella support from January 2019 to April 2023, approved by the Mayo Clinic Institutional Review Board. We collected data on demographics, AMPAC scores, and outcomes at three time points. Continuous variables were compared using the T-test or Mann-Whitney test, and categorical variables using the Chi-square or Fisher's exact test. We used a linear regression model to investigate the relationship between rehabilitation duration and AMPAC scores. Quantile regression was preferred due to the non-normal distribution of the outcome, hospital-free days. Results: We conducted a linear regression analysis and found a statistically significant association between increased hours spent in PT and greater improvement. After one hour of physical therapy, there was an average increase of 1.07 (95% CI 0.1, 2; p=0.03) in AMPAC scoore. We also compared the change in the AMPAC score with hospital-free days, and it was statistically significant in quantile regression analysis, indicating an increase of 0.28 (95% CI 0.2, 0.55; P=0.03) points in the AMPAC Score, corresponding to an additional hospital-free day. Conclusion: Increased hours spent in physical therapy show a significant positive association with greater improvement in standardized AM-PAC Mobility scores and hospital-free days. These findings encourage increasing uptake and support of cardiac rehabilitation programs.

Background: In the landscape of organ transplantation, heart transplantation stands as a life-saving procedure for patients with end-stage heart failure. Comprehensive analyses of transplant programs are imperative to optimize outcomes and understand the complexities. Hypothesis: This study hypothesizes that an increasing trend of heart transplant service and short-term mechanical circulatory support (STMCS) is the bridge to transplant; the UNOS (United Network for Organ Sharing) guideline positively impacts STMCS utilization. Even with the standard of care, there might be a disparity in receiving care in terms of gender and race. Goal/ Aims: By examining this center's collective experience, this research provides valuable insights into the evolving landscape of heart transplantation, ultimately contributing to advancements in patient care and transplant policy. Methods: This retrospective cohort study includes heart transplant patients in a single large transplant center. For statistical analysis, Cox regression, Mann-Whitney test, Kruskal Wallis, and Chi-Square test were used in IBM SPSS 25. Result: Trends: This retrospective study covering 2010 to 2022 comprehensively analyzed 1513 heart transplant patients. The cohort consisted of 1071 (70.78%) males and 442 (29.21%) females, 31.9% were bridged through STMCS. 76.7% of Caucasian and 16.1% were African American.The mean utilization of STMCS was 20.08% before the UNOS policy change, increasing to 53.81% after that (p < 0.001). Disparity Analysis: There was a statistically significant difference in STMCS utilization between white and black patients (p= 0.008) but no difference in between obese and non-obese cohorts (P=0.362).Wait time was similar among the genders (p=0.161) and different races (p=0.302). Survival Analysis: There is a significant survival discrepancy between patients bridged through MCS and those without STMCS(p< 0.001). However, yearly trend analysis showed an evolving survival trajectory favoring STMCS users. There are statistically significant survival differences among whites and blacks (P =0.008) but similar among the genders (p=0.589). Summary: The study reveals significant changes in the trend of transplants regarding STMCS utilization since the UNOS guideline. There are substantial differences in survival between STMCS vs. non-STMCS groups and among the races.There was a significant difference in STMCS utilization among the races.

Background. Static cold storage is a mainstay of the heart transplantation (HTx) process. However, the temperature distribution within the organ at each stage of HTx is unknown. In this study, we aimed to quantify how long it took for the heart to warm up and cool down and the nature of temperature distribution with the organ at each stage of HTx. Methods. We used high-fidelity computational time-varying biothermal modeling on an anatomical human heart model to model the HTx process in 5 interdependent stages, including cardioplegia, back-table preparation, static cold storage ice box storage and transport, back-table preparation at the recipient institution and warm-up within the recipient body before cross-clamp release. Results. Results indicate that the heart experiences roller-coaster-like temperature changes in stage, including rapid cool down from body temperature to <10 °C within 15 min in stage 1 with a maximum cooling rate of 5 °C/min. This was followed by cooling and extended duration of temperatures <2 °C in the ice box and rapid warming up to body temperature within 10 min at rates of 2 °C/min and 4 °C/min for the left and right sides, respectively, during implantation. Temperature distribution throughout the heart was heterogeneous, with right-sided temperature change occurring nearly 2× faster than on the left side. Conclusions. We present, for the first time, detailed temperature distributions and evolution at each stage of HTx. Quantification of the rapid and heterogeneous temperature changes is crucial to optimize HTx and improve organ viability.

Extracorporeal membrane oxygenation (ECMO) is often used in acute respiratory distress syndrome (ARDS) with refractory hypoxemia. There is limited literature highlighting the development of right ventricular (RV) failure while on ECMO. We conducted a retrospective multicenter observational study including 70 patients who were placed on veno-venous (VV)-ECMO for respiratory failure at Mayo Clinic, Jacksonville, and Mayo Clinic, Rochester, between January 2018 and June 2022 and had at least two post-ECMO transthoracic echoes. The primary outcomes were the incidence and progression of RV dysfunction and dilatation. The secondary outcome was in-patient mortality. Among 70 patients in our cohort, 60.6% had a normal RV function at the time of ECMO placement, whereas only 42% had a normal RV function at the second post-ECMO echo. On multinomial regression, a moderate decrease in RV function was associated with ECMO flow (odds ratio [OR] = 2.32, p = 0.001) and ECMO duration (OR = 1.01, p = 0.01). A moderately dilated RV size was also associated with ECMO flow (OR = 2.62, p < 0.001) and ECMO duration (OR = 1.02, p = 0.02). An increasing degree of RV dysfunction was associated with worse outcomes. Our study showed that the increasing duration and flow of VV-ECMO correlated with progressive RV dilatation and dysfunction, which were associated with poor survival.