Revisions to the heart allocation criteria in 2018 motivated an increased use of extracorporeal membrane oxygenation (ECMO) as a bridge to transplantation. Studies have demonstrated inferior post-transplant outcomes in patients bridged with ECMO but do not account for underlying diagnosis. Our objective was to elucidate the differential impact of ECMO on outcomes by heart failure (HF) etiology. The United Network of Organ Sharing database was queried for adults who underwent isolated heart transplantation after October 2018. Patients were stratified by ECMO utilization at the time of transplantation and then by HF etiology. After baseline statistical comparisons, survival analysis relied on Kaplan-Meier estimates and Cox proportional models. A total of 13,203 patients were included, of whom 761 (5.8%) were supported with ECMO. ECMO patients were younger (48 vs 54 years, p < 0.001), less likely to have diabetes (24% vs 30%, p < 0.001), smoke cigarettes (31% vs 41%, p < 0.001), or have prior cardiac surgery (29% vs 36%, p < 0.001), more likely to require dialysis (20% vs 5%, p < 0.001), and spent fewer days on the waitlist (59 vs 190, p < 0.001). After adjustment, ECMO was associated with increased mortality (hazard ratio 1.85, p < 0.001) in the full cohort. After incorporating HF etiology, this increased mortality risk persisted in all subgroups except restrictive cardiomyopathy and congenital heart disease (CHD). Our findings illustrate that HF etiology is associated with differing outcomes when bridging with ECMO. ECMO patients with restrictive cardiomyopathy or CHD did not have increased mortality risk. With ECMO utilization increasing, these data are hypothesis-generating and serve as a basis for further studies.

We aimed to describe practice patterns and outcomes in patients with extracorporeal membrane oxygenation (ECMO) support throughout the coronavirus 2019 (COVID-19) pandemic, with the hypothesis that mortality would improve as we accumulated knowledge and experience. We included 48 patients supported on veno-venous ECMO (VV-ECMO) at a single institution between April 2020 and December 2021. Patients were categorized into three waves based on cannulation date, corresponding to the wild-type (wave 1), alpha (wave 2), and delta (wave 3) variants. One hundred percent of patients in waves 2 and 3 received glucocorticoids, compared with 29% in wave 1 (p < 0.01), and the majority received remdesivir (84% and 92% in waves 2 and 3, vs. 35% in wave 1; p < 0.01). Duration of pre-ECMO noninvasive ventilation was longer in waves 2 and 3 (mean 8.8 days and 3.9 days, vs. 0.7 days in wave 1; p < 0.01), as was time to cannulation (mean 17.2 and 14.6 days vs. 8.8 days in wave 1; p < 0.01) and ECMO duration (mean 55.7 days and 43.0 days vs. 28.4 days in wave 1; p = 0.02). Mortality in wave 1 was 35%, compared with 63% and 75% in waves 2 and 3 (p = 0.05). These results suggest an increased prevalence of medically refractory disease and rising mortality in later variants of COVID-19.

Background: Until local healthcare infrastructure is strengthened, cardiac surgical care in low- and middle-income countries is often provided by non-governmental organizations by way of visiting healthcare teams. This is generally considered to be a cost-effective alternative to transporting patients to high income countries for surgical care, but the costs of cardiac surgery consumables under this model are poorly understood. Our objective was to identify the per-patient cost of cardiac surgery consumables used in single and double valve replacements performed by a non-governmental organization in Rwanda. Methods: Financial data from 2020 were collected from Team Heart, a non-governmental organization that supports cardiac surgical care in Rwanda. A comprehensive list of consumables was generated, including surgical, perfusion, anesthesia, and inpatient supplies and medications. Acknowledging the variability in perioperative needs, the quantities of consumables were calculated from an average of six patients who underwent single or double-valve replacement in 2020. Total costs were calculated by multiplying purchasing price by average quantity per patient. Costs absorbed by the local hospital were excluded from the calculations. Results: The total cost per patient was estimated at $9,450. Surgical supplies comprised the majority of costs ($6,140 per patient), with the most substantial cost being that of replacement valves ($3,500 per valve), followed by surgical supplies ($1,590 per patient). Conclusions: This preliminary analysis identifies a cost of just over $9,000 per patient for consumables used in cardiac valve surgery in Rwanda, which is lower than the estimated costs of transporting patients to centers in high income countries. This work highlights the relative cost effectiveness of cardiac surgical care in low- and middle- income countries under this model and will be instrumental in guiding the allocation of local and international resources in the future.

Background and Aim: Ex vivo models of functional tricuspid regurgitation (FTR) are needed for pre-clinical testing of novel surgical and interventional repair strategies, but current options are costly or have not been formally validated. The objective of this research was to create and validate an ex vivo model to test novel repair methods for FTR. Methods: In explanted porcine hearts, the right atrium was excised to visualize the tricuspid valve. The pulmonary artery and aorta were clamped and cannulated, the coronary arteries ligated, and the right and left ventricles statically pressurized with air to 30 mmHg and 120 mmHg, respectively. FTR was induced by increasing right ventricular pressure to 80 mmHg for 3 h, which resulted in progressive tricuspid annular enlargement, right ventricular dilation, papillary muscle displacement, and central tricuspid malcoaptation. A structured light scanner was used to image the 3D topography of the tricuspid valve in both the native and FTR state, and images were exported into scan-to-computer-aided design software, which allowed for high-resolution 3D computational reconstruction. Relevant geometric measurements were sampled including annular circumference and area, major and minor axis diameter, and tenting height, angle, and area. Geometric measurements from the ex vivo model were compared to clinical transthoracic echocardiographic (TTE) measurements using two-sample t-tests. Results: A total of 12 porcine hearts were included in the study. Annular measurements of the native valve were comparable to published TTE data, except for the minor axis diameter, which was shorter in the ex vivo model (2.5 vs. 3.1 cm, P = 0.007). Induction of FTR in the ex vivo model resulted in annular enlargement (FTR vs. native: circumference 13.7 vs.11.8 cm, P = 0.012; area 14 vs. 11 cm2, P = 0.011). Ex vivo leaflet measurements in both the native and FTR model differed from published TTE data, but demonstrated comparable directional changes between the native and regurgitant states, including increased tenting height, area, and volume. Conclusion: The ex vivo pneumatically-pressurized porcine model closely recapitulates the geometry of both the native and regurgitant tricuspid valve complex in humans and holds promise for testing novel FTR repair strategies. Relevance for Patients: Currently available interventions for the tricuspid valve have a risk of permanent conduction abnormalities and are insufficient in addressing tricuspid disease for a subset of patients. This ex vivo model provides a platform for testing of novel interventions that address the deficiencies of current tricuspid therapies.