Investigating Cardiac Temperature During Heart Transplantation Using the Static Cold Storage Paradigm.

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.

Multidisciplinary Management Strategies for Long COVID: A Narrative Review.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused millions of infections to date and has led to a worldwide pandemic. Most patients had a complete recovery from the acute infection, however, a large number of the affected individuals experienced symptoms that persisted more than 3 months after diagnosis. These symptoms most commonly include fatigue, memory difficulties, brain fog, dyspnea, cough, and other less common ones such as headache, chest pain, paresthesias, mood changes, muscle pain, and weakness, skin rashes, and cardiac, endocrine, renal and hepatic manifestations. The treatment of this syndrome remains challenging. A multidisciplinary approach to address combinations of symptoms affecting multiple organ systems has been widely adopted. This narrative review aims to bridge the gap surrounding the broad treatment approaches by providing an overview of multidisciplinary management strategies for the most common long COVID conditions.

Assessing Right Ventricle Over Time in Patients on Veno-Venous Extracorporeal Membrane Oxygenation: Insights From Serial Echocardiography.

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.

Outcome of lung transplantation in patients with pulmonary alveolar microlithiasis in the era of COVID-19 infection.

Lung transplant recipients are at higher risk of developing COVID-19 infection compared to other solid organ transplants. The risk further increases in the unvaccinated patients. We present a case of a 43-year-old male who underwent bilateral sequential lung transplantation for pulmonary alveolar microlithiasis (PAM) and had an uneventful recovery. However, two years post-transplantation, the patient developed chronic lung allograft dysfunction (CLAD) with bronchiolitis obliterans syndrome and two episodes of COVID-19 infection. During the second episode of COVID-19 infection, the patient developed sepsis and multi-organ dysfunction ultimately resulting in death. Our case report highlights the increased susceptibility of PAM patients' post-lung transplant to COVID-19 infection. Continuous follow-up of PAM patients' post-lung transplantation is necessary to prevent unfavorable outcomes.

Quadricuspid Aortic Valve: Imaging, Diagnosis, and Prognosis.

Quadricuspid aortic valve is a rare congenital cardiac anomaly with an incidence of 0.008% to 0.043%. Its clinical course varies depending on cusp anatomy, function, and associated cardiac malformations. It frequently progresses to aortic valve regurgitation that may require surgical valve replacement. Detection has shifted from incidental discovery during autopsies or cardiac surgeries in the early 20th century to various cardiac imaging methods in recent decades. In addition to contributing to the literature, this report supports the use of transesophageal echocardiography more liberally to detect aortic valve abnormalities. The case presents a 48-year-old female patient with an incidentally discovered quadricuspid aortic valve.

Impact of controlled hypothermic preservation on outcomes following heart transplantation.

BACKGROUND: Severe primary graft dysfunction (PGD) is a major cause of early mortality after heart transplant, but the impact of donor organ preservation conditions on severity of PGD and survival has not been well characterized. METHODS: Data from US adult heart-transplant recipients in the Global Utilization and Registry Database for Improved Heart Preservation-Heart Registry (NCT04141605) were analyzed to quantify PGD severity, mortality, and associated risk factors. The independent contributions of organ preservation method (traditional ice storage vs controlled hypothermic preservation) and ischemic time were analyzed using propensity matching and logistic regression. RESULTS: Among 1,061 US adult heart transplants performed between October 2015 and December 2022, controlled hypothermic preservation was associated with a significant reduction in the incidence of severe PGD compared to ice (6.6% [37/559] vs 10.4% [47/452], p = 0.039). Following propensity matching, severe PGD was reduced by 50% (6.0% [17/281] vs 12.1% [34/281], respectively; p = 0.018). The Kaplan-Meier terminal probability of 1-year mortality was 4.2% for recipients without PGD, 7.2% for mild or moderate PGD, and 32.1%, for severe PGD (p < 0.001). The probability of severe PGD increased for both cohorts with longer ischemic time, but donor hearts stored on ice were more likely to develop severe PGD at all ischemic times compared to controlled hypothermic preservation. CONCLUSIONS: Severe PGD is the deadliest complication of heart transplantation and is associated with a 7.8-fold increase in probability of 1-year mortality. Controlled hypothermic preservation significantly attenuates the risk of severe PGD and is a simple yet highly effective tool for mitigating post-transplant morbidity.

Association between Impella device support and elevated rates of gout flares: a retrospective propensity-matched study.

BACKGROUND: Impella is an advanced ventricular assist device frequently used as a bridge to heart transplantation. The association of Impella with increased rates of gout flares has not been studied. Our primary aim is to determine the rates of gout flares in patients on Impella support. METHODOLOGY: A retrospective study was conducted between January 2017 and September 2022 involving all patients who underwent heart transplantation. The cohort was divided into two groups based on Impella support for statistical analysis. In patients receiving Impella support, outcome measures were compared based on the development of gout flares. 1:1 nearest neighbor propensity match, as well as inverse propensity of treatment weighted analyses, were performed to explore the causal relationship between impella use and gout flare in our study population. RESULTS: Our analysis included 213 patients, among which 42 (19.71%) patients were supported by Impella. Impella and non-Impella groups had similar age, race, and BMI, but more males were in the Impella group. Gout and chronic kidney disease were more prevalent in Impella-supported patients, while coronary artery disease was less common. The prevalence of gout flare was significantly higher in Impella patients (30.9% vs. 5.3%). 42 Impella-supported patients were matched with 42 patients from the non-impella group upon performing a 1:1 propensity matching. Impella-supported patients were noted to have a significantly higher risk of gout flare (30.9% vs. 7.1%, SMD = 0.636), despite no significant difference in pre-existing gout history and use of anti-gout medications. Impella use was associated with a significantly increased risk of gout flare in unadjusted (OR 8.07), propensity-matched (OR 5.83), and the inverse propensity of treatment-weighted analysis (OR 4.21). CONCLUSION: Our study is the first to identify the potential association between Impella support and increased rates of gout flares in hospitalized patients. Future studies are required to confirm this association and further elucidate the biological pathways. It is imperative to consider introducing appropriate measures to prevent and promptly manage gout flares in Impella-supported patients.

A novel flood risk management approach based on future climate and land use change scenarios.

Climate change and increasing urbanization are two primary factors responsible for the increased risk of serious flooding around the world. The prediction and monitoring of the effects of land use/land cover (LULC) and climate change on flood risk are critical steps in the development of appropriate strategies to reduce potential damage. This study aimed to develop a new approach by combining machine learning (namely the XGBoost, CatBoost, LightGBM, and ExtraTree models) and hydraulic modeling to predict the effects of climate change and LULC change on land that is at risk of flooding. For the years 2005, 2020, 2035, and 2050, machine learning was used to model and predict flood susceptibility under different scenarios of LULC, while hydraulic modeling was used to model and predict flood depth and flood velocity, based on the RCP 8.5 climate change scenario. The two elements were used to build a flood risk assessment, integrating socioeconomic data such as LULC, population density, poverty rate, number of women, number of schools, and cultivated area. Flood risk was then computed, using the analytical hierarchy process, by combining flood hazard, exposure, and vulnerability. The results showed that the area at high and very high flood risk increased rapidly, as did the areas of high/very high exposure, and high/very high vulnerability. They also showed how flood risk had increased rapidly from 2005 to 2020 and would continue to do so in 2035 and 2050, due to the dynamics of climate change and LULC change, population growth, the number of women, and the number of schools - particularly in the flood zone. The results highlight the relationships between flood risk and environmental and socio-economic changes and suggest that flood risk management strategies should also be integrated in future analyses. The map built in this study shows past and future flood risk, providing insights into the spatial distribution of urban area in flood zones and can be used to facilitate the development of priority measures, flood mitigation being most important.

Absorbable antibiotic beads for treatment of LVAD driveline infections.

BACKGOUND: Infections of the left ventricular assist device (LVAD) driveline are a dreaded complication that results in high mortality and morbidity. METHOD: We retrospectively reviewed five consecutive patients with severe continuous-flow LVAD (HVAD, Heartmate 2, and Heartmate 3) driveline infection. These infections, which developed on an average of 960.4 ± 843.9 days after LVAD placement, were refractory to systemic antibiotics and local wound care. All were treated with extensive surgical debridement, local installation of absorbable antibiotic-loaded calcium sulfate beads (vancomycin and tobramycin), primary wound closure, and 6 weeks of systemic antibiotics after surgery. RESULTS: Four patients had resolution of DLI, and one had a recurrent infection at another part of the driveline 7 months after the complete resolution of the previous site. This patient was successfully treated with debridement and bead placements. Three patients still have their LVADs, while two received orthotopic heart transplants. At the time of the transplant, there was no evidence of gross infection of the LVAD drivelines or pumps. At the average follow-up time of 425.8 ± 151 days, no patients have an active infection. CONCLUSION: Treatment of LVAD driveline infection with absorbable antibiotic beads with primary wound closure is a viable option and merits further investigation.

Percutaneous Transseptal Extracorporeal Membrane Oxygenation to Rescue a Failing Right Ventricle in an Animal Model.

OBJECTIVE: We tested the feasibility and effectiveness of a percutaneous atrial transseptal extracorporeal membrane oxygenation (ECMO) cannulation strategy in a right ventricular failure (RVF) model. METHODS: We performed 4 nonsurvival porcine experiments. Percutaneous transseptal access was achieved using a steerable introducer. For guidance, we used fluoroscopy, transesophageal echocardiogram (TEE), and intracardiac echocardiography (ICE). A ProtekDuo rapid deployment cannula (LivaNova, London, UK) was advanced across the septum into the left atrium by 2 to 3 cm. Pulmonary hypertension (PH) was induced by partially clamping the pulmonary artery. ECMO flow was cycled from high (2 to 3 L/min) to low (0.2 to 0.3 L/min) over 2 to 3 hours. RESULTS: Transseptal access using TEE and fluoroscopy was successful in 1 animal and unsuccessful in 1 animal. ICE provided optimal visualization for the remaining 2 animals. Mean arterial pressure (MAP) was associated immediately and consistently with high versus low ECMO flow rate (mean difference: 29 ± 3.1 mm Hg, P = 0.004) but was not restored to baseline values. RV pressure values were dynamic. Given time to equilibrate, mean RV pressure was restored to a baseline level. CONCLUSIONS: Percutaneous right atrium to left atrium transseptal cannulation relieved PH-RVF. MAP was restored to a viable level, and mean RV pressure was restored to a baseline level. Transseptal ECMO shows promise as a cannulation strategy to bridge patients with PH-RVF to lung transplant.

Axillary mechanical circulatory support improves renal function prior to heart transplantation in patients with chronic kidney disease.

Impaired kidney function is often associated with acute decompensation of chronic heart failure and portends a poor prognosis. Unfortunately, current data have demonstrated worse survival in patients with acute kidney injury than in patients with chronic kidney disease during durable LVAD placement as bridge therapy. Furthermore, end-stage heart failure patients undergoing combined heart-kidney transplantation have poorer short- and long-term survival than heart transplants alone. We evaluated the kidney function recovery in our heart failure population awaiting heart transplantation at our institution, supported by temporary Mechanical Circulatory Support (tMCS) with Impella 5.5. The protocol (#22004000) was approved by the Mayo Clinic institutional review board, after which we performed a retrospective review of all patients with acute on chronic heart failure and kidney disease in patients considered for only heart and kidney combined organ transplant and supported by tMCS between January 2020 and February 2021. Hemodynamic and kidney function trends were recorded and analyzed before and after tMCS placement and transplantation. After placement of tMCS, we observed a trend towards improvement in creatinine, Fick cardiac index, mixed venous saturation, and glomerular filtration rate (GFR), which persisted through transplantation and discharge. The average duration of support with tMCS was 16.5 days before organ transplantation. The median pre-tMCS creatinine was 2.1 mg/dL (IQR 1.75-2.3). Median hematocrit at the time of tMCS placement was 32% (IQR 32-34), and the median estimated glomerular filtration rate was 34 mL/min/BSA (34-40). The median GFR improved to 44 mL/min/BSA (IQR 45-51), and serum creatinine improved to 1.5 mg/dL (1.5-1.8) after tMCS. Median discharge creatinine was 1.1 mg/dL (1.19-1.25) with a GFR of 72 (65-74). None of these six patients supported with tMCS required renal replacement therapy after heart transplantation. Early adoption of Impella 5.5 in this patient population resulted in renal recovery without needing renal replacement therapies or dual organ transplantation and should be further evaluated.

Trends and predictors of intracranial hemorrhage in patients with advanced heart failure on left ventricular assist device from 2005 to 2014 in the United States.

OBJECTIVES: Left ventricular assist devices are known to extend survival in patients with advanced heart failure; however, their association with intracranial hemorrhage is also well-known. We aimed to explore the risk trend and predictors of intracranial hemorrhage in patients with left ventricular assist devices. MATERIAL AND METHODS: We included patients aged 18 years or older with left ventricular assist devices hospitalized in the US from 2005 to 2014 using the National Inpatient Sample. We computed the survey-weighted percentages with intracranial hemorrhage across the 10-year study period and assessed whether the proportions changed over time. Predictors of intracranial hemorrhage were evaluated using multivariable logistic regression model. RESULTS: Of 33,246 hospitalizations, 568 (1.7%) had intracranial hemorrhage. The number of left ventricular assist devices placements increased from 873 in 2005 to 5175 in 2014. However, the risk of intracranial hemorrhage remained largely unchanged (1.7% to 2.3%; linear trend, P = 0.604). The adjusted odds of intracranial hemorrhage were increased with the presence of one of the following variables: female sex (odds ratio [OR], 1.58; 95% CI, 1.03-2.43), history of ischemic stroke (OR, 3.13; 95% CI, 1.86-5.28), or Charlson Comorbidity Index score of 3 or more (OR, 77.40; 95% CI, 10.03-597.60). CONCLUSIONS: Over the last decade, the risk of intracranial hemorrhage has remained relatively unchanged despite an increase in the use of left ventricular assist devices in patients with advanced heart failure. Women, higher Charlson Comorbidity Index scores, and history of ischemic stroke were associated with higher odds of intracranial hemorrhage in patients with left ventricular assist devices.

A Paradigm Shift in Heart Preservation: Improved Post-transplant Outcomes in Recipients of Donor Hearts Preserved With the SherpaPak System.

Traditional ice storage has been the historic standard for preserving donor's hearts. However, this approach provides variability in cooling, increasing risks of freezing injury. To date, no preservation technology has been reported to improve survival after transplantation. The Paragonix SherpaPak Cardiac Transport System (SCTS) is a controlled hypothermic technology clinically used since 2018. Real-world evidence on clinical benefits of SCTS compared to conventional ice cold storage (ICS) was evaluated. Between October 2015 and January 2022, 569 US adults receiving donor hearts preserved and transported either in SCTS (n = 255) or ICS (n = 314) were analyzed from the Global Utilization And Registry Database for Improved heArt preservatioN (GUARDIAN-Heart) registry. Propensity matching and a subgroup analysis of >240 minutes ischemic time were performed to evaluate comparative outcomes. Overall, the SCTS cohort had significantly lower rates of severe primary graft dysfunction (PGD) ( p = 0.03). When propensity matched, SCTS had improving 1-year survival ( p = 0.10), significantly lower rates of severe PGD ( p = 0.011), and lower overall post-transplant MCS utilization ( p = 0.098). For patients with ischemic times >4 hours, the SCTS cohort had reduced post-transplant MCS utilization ( p = 0.01), reduced incidence of severe PGD ( p = 0.005), and improved 30-day survival ( p = 0.02). A multivariate analysis of independent risk factors revealed that compared to SCTS, use of ice results in a 3.4-fold greater chance of severe PGD ( p = 0.014). Utilization of SCTS is associated with a trend toward increased post-transplant survival and significantly lower severe PGD and MCS utilization. These findings fundamentally challenge the decades-long status quo of transporting donor hearts using ice.

Iatrogenic Acute Ascending Aortic Dissection During Combined Heart/Liver Transplant for Amyloidosis.

We report a case of iatrogenic acute type A aortic dissection (ATAAD) during a combined heart-liver transplant in a patient with amyloid-associated cardiac and hepatic failure. The patient developed ATAAD of the recipient's aorta during the heart transplantation. Because there was no sign of malperfusion or proximal extension into the donor aorta, we proceeded with the liver transplantation and continued medical management for ATAAD. The patient was discharged uneventfully 30 days after the transplant, and computed tomography coronary angiogram after 4 months showed stable dissection. During a heart transplant, ATAAD of the native aorta without malperfusion syndrome can be managed conservatively with close progress monitoring.

Novel treatment of bronchopleural fistula in a lung transplant recipient with endobronchial sealant and endobronchial valve placement via robotic-assisted bronchoscopy.

Bronchopleural fistulas (BPFs) are a dreaded complication following pulmonary surgery. Endobronchial valves (EVs), with endobronchial sealant (ES), instilled with robotic bronchoscopy (RB), allow occlusion of BPF, avoiding surgery. The patient was a 71-year-old woman with a history of chronic obstructive pulmonary disease and bronchiectasis who underwent bilateral lung transplantation and wedge resection of the right middle lobe and left lingula. A BPF was discovered on postoperative day (POD) 21. Conservative measures with chest tubes failed, and robotic-assisted bronchoscopy aided in reaching the bronchial segment and instilling ES, and EV was deployed with the conventional bronchoscope. The pneumothorax was cleared 12 days later, and on POD 56, she was discharged. The RB procedure was successful, with no pneumothorax or BPF symptoms after a median follow-up of POD 284. Robotic endobronchial closure of BPF with EV and ES is an effective treatment option avoiding invasive surgeries.