The impact of the Impeller's hub design on the performance and blood damage in a microaxial mechanical circulatory support device - A numerical study.

This study uses CFD methods to investigate the effects of the impeller's geometry on the hemodynamic characteristics, pump performance, and blood damage parameters, in a percutaneous microaxial Mechanical Circulatory Support (MCS) device. The numerical simulations employ the steady state Reynolds-Averaged Navier-Stokes approximation using the SST k-ω turbulent model. Three different impeller models are examined with different hub conversion angles (α = 0○, 3○ and 5○). The analysis includes 23 cases for different pressure heads (Δp = 60-80 mmHg) and angular velocities (ω = 30-52 kRPM). The obtained flow rate is compared between the cases to assess the effect of the impeller's design and working conditions on the pump performance. The comparative risk of shear-induced platelet activation is estimated using the statistical median of the stress-accumulation values calculated along streamlines. The risk of hemolysis is estimated using the average exposure time to shear stress above a threshold (τ > 425 Pa). The results reveal that the shape of the impeller's hub has a great impact on the flow patterns, performance, and risk of blood damage, as well as the angular velocity. The highest flow rate (Q = 3.7 L/min) and efficiency (η = 11.3 %) were achieved using a straight hub (α = 0○). Similarly, for the same condition of flow and pressure, the straight hub impeller has the lowest blood damage risk parameters. This study shed light on the effect of pump design on the performance and risk of blood damage, indicating the roles of the hub shape and angular velocity as dominant parameters.

The use of venoarterial extracorporeal membrane oxygenation in cardiogenic shock: a narrative review.

Aims: Cardiogenic shock (CS) develops in up to 10% of patients with acute myocardial infarction (AMI) and carries a 50% risk of mortality. Despite the paucity of evidence regarding its benefits, venoarterial extracorporeal membrane oxygenation (VA-ECMO) is increasingly used in clinical practice in patients with AMI in CS (AMI-CS). This review aims to provide an in-depth description of the four available randomized controlled trials to date designed to evaluate the benefit of VA-ECMO in patients with AMI-CS. Methods and results: The literature search was conducted on PubMed, Google Scholar, and clinicaltrials.gov to identify the four relevant randomized control trials from years of inception to October 2023. Despite differences in patient selection, nuances in trial conduction, and variability in trial endpoints, all four trials (ECLS-SHOCK I, ECMO-CS, EUROSHOCK, and ECLS-SHOCK) failed to demonstrate a mortality benefit with the use of VA-ECMO in AMI-CS, with high rates of device-related complications. However, the outcome of these trials is nuanced by the limitations of each study that include small sample sizes, challenging patient selection, and high cross-over rates to the intervention group, and lack of use of left ventricular unloading strategies. Conclusion: The presented literature of VA-ECMO in CS does not support its routine use in clinical practice. We have yet to identify which subset of patients would benefit most from this intervention. This review emphasizes the need for designing adequately powered trials to properly assess the role of VA-ECMO in AMI-CS, in order to build evidence for best practices.

Temporary mechanical circulatory support as a bridge to durable left ventricular assist device as destination therapy in fulminant giant cell myocarditis：A case report.

Fulminant giant cell myocarditis is a fatal form of acute myocarditis leading to a rapid-onset clinical presentation with lethal arrhythmias, acute heart failure, or cardiogenic shock requiring mechanical circulatory support. We report the case of a 52-year-old female diagnosed with fulminant myocarditis requiring veno-arterial extracorporeal membrane oxygenation (V-A ECMO) and intra-aortic balloon pump(IABP) support. Due to hemodynamic instability, she was transferred to our hospital by helicopter on day 4. On arrival at our hospital, she underwent percutaneous balloon atrial septostomy to decompress the left ventricle. Although the left ventricular distension and pulmonary edema improved after atrial septostomy, no signs of biventricular function recovery were identified on day 14. On day 23, V-A ECMO and IABP were switched to a durable left ventricular assist device(LVAD) system and a right ventricular assist device(RVAD) with ECMO (RVAD-ECMO) under median sternotomy. On day 37, RVAD-ECMO was eventually removed and rehabilitation was started with the remaining LVAD support as destination therapy. On day 78, the patient was finally discharged with LVAD support to follow-up as an outpatient. This case underscores the importance of a multidisciplinary approach and rigorous monitoring to optimize outcomes in the treatment of fulminant giant cell myocarditis.

Circulatory support with triple cannulation V-PaA ECMO in a patient with acute right ventricular failure and refractory hypoxemia secondary to diffuse alveolar hemorrhage: A case report.

A 48-year-old woman presented to the emergency department with a one-week history of progressive dyspnea. During her hospitalization, the diagnosis of diffuse alveolar hemorrhage was made. She subsequently developed respiratory failure and acute right ventricular failure. Despite medical treatment, she continued to experience distributive shock due to a generalized inflammatory response. Circulatory support with ECMO was needed. We opted for triple cannulation to manage the multiorgan failure as a bridge to recovery. We describe our experience with an uncommon cannulation technique: veno-pulmonary-arterial cannulation, which enabled us to address cardiogenic shock, refractory hypoxemia, and distributive shock, leading to the successful recovery of the patient.

Preemptive Impella 5.5 insertion to reduce operative risk in high-risk cardiac surgery: A case report.

INTRODUCTION AND IMPORTANCE: Society of thoracic surgery (STS) risk score has been used as a tool to gauge operative risk of cardiac surgery patients. High-risk patients, with STS risk score > 8 %, are considered as having prohibitive risk and are not offered surgery. There is no established strategy to minimize postoperative hemodynamic instability using mechanical circulatory support (MCS), despite growing interest in utilizing MCS prior to hemodynamic instability. The Impella 5.5 can provide enough perfusion and unload the left ventricle. CASE PRESENTATION: We managed a 75-year-old male with multiple comorbidities and a presumed Society of Thoracic Surgeons (STS) score higher than 9.8 %, who had redo coronary artery bypass grafting and aortic and mitral valve replacement with concomitant implantation of the Impella 5.5. Patient had a good recovery despite developing post-operative atrial fibrillation. DISCUSSION: Impella is used as a mechanical circulatory support device in patients with cardiogenic shock. It provides forward flow and effectively unloads the left ventricle. The concomitant placement of the Impella 5.5 in high-risk cardiac candidates may be associated with reduced operative risk. CONCLUSION: Placement of the device as part of surgical plan can potentially mitigate the perioperative risk by providing adequate endogean perfusion, decrease pressor support, unloading LV.

Safety and utility of mechanical circulatory support in patients with acute myocardial infarction complicated by cardiogenic shock: A systematic review and meta-analysis.

BACKGROUND: Acute myocardial infarction complicated by cardiogenic shock (AMI-CS) is a major cause of morbidity and mortality. Although mechanical circulatory support (MCS) is an increasingly utilized therapeutic option in AMI-CS, studies evaluating the efficacy and safety of different forms of MCS have yielded conflicting results. This systematic review and meta-analysis aims to evaluate the safety and efficacy of different forms of MCS. METHODS: A database search was performed for studies reporting on the association of different forms of MCS with clinical outcomes in patients with AMI-CS. The primary efficacy endpoints were short term (≤30 days) and long term (>30 days) all-cause mortality. Secondary efficacy endpoints included recurrent AMI, cardiovascular (CV) mortality, device-related limb complications, moderate to severe bleeding events, and cerebrovascular accidents (CVA). RESULTS: 2752 patients with AMI-CS met inclusion criteria. Results were available comparing ECMO to other MCS or medical therapy alone, comparing IABP to medical therapy alone, and comparing pLVAD to IABP. Use of ECMO was not associated with lower risk of 30-day or long-term mortality compared to pVAD or standard medical therapy with or without IABP placement but was associated with higher risk of device-related limb complications and moderate to severe bleeding compared to pVAD. IABP use was not associated with a lower risk of 30 day or long-term mortality but was associated with higher risk of recurrent AMI and moderate to severe bleeding compared to medical therapy. Compared to IABP, pVAD use was associated with lower risk of CV mortality but not recurrent AMI. pVAD was associated with a higher risk of device-related limb complications and moderate to severe bleeding compared to IABP use. CONCLUSION: Use of ECMO or IABP in patients with AMI-CS is not associated with significant improvement in mortality. pVAD is associated with a lower risk of CV mortality. All MCS types are associated with increased risk of complications. Additional high-quality studies are needed to determine the optimal MCS therapy for patients with AMI-CS.

Implantation and removal of central temporary paracorporeal biventricular support for COVID-19-associated myocarditis.

This case report illustrates how to implant a central paracorporeal temporary biventricular assist device in a 17-year-old patient with acute heart failure due to a fulminant form of coronavirus disease 2019 myocarditis. The procedure was carried out after prior veno-arterial extracorporeal membrane oxygenation support. Myocardial biopsies and biventricular assist device explants are also included in the report. The patient was weaned on postoperative day 6 and discharged without any significant complications. One year after the event, the patient remains asymptomatic with normal biventricular function and a normal lifestyle.

Cardiac power output ratio: Novel survival predictor after percutaneous ventricular assist device in cardiogenic shock.

AIMS: Currently, there is limited data on prognostic indicators after insertion of percutaneous ventricular assist device (PVAD) in the treatment of cardiogenic shock (CS). This study evaluated the prognostic role of cardiac power output (CPO) ratio, defined as CPO at 24 h divided by early CPO (30 min to 2 h), in CS patients after PVAD. METHODS AND RESULTS: Consecutive CS patients from the QEH-PVAD Registry were followed up for survival at 90 days after PVAD. Among 121 consecutive patients, 98 underwent right heart catheterization after PVAD, with CPO ratio available in 68 patients. The CPO ratio and 24-h CPO, but not the early CPO post PVAD, were significantly associated with 90-day survival, with corresponding area under curve in ROC analysis of 0.816, 0.740, and 0.469, respectively. In multivariate analysis, only the CPO ratio and lactate level at 24 h remained as independent survival predictors. The CPO ratio was not associated with age, sex, and body size. Patients with lower CPO ratio had significantly lower coronary perfusion pressure, worse right heart indices, and higher pulmonary vascular resistance. A lower CPO ratio was also significantly associated with mechanical ventilation and higher creatine kinase levels in myocardial infarction patients. CONCLUSION: In post-PVAD patients, the CPO ratio outperformed the absolute CPO values and other haemodynamic metrics in predicting survival at 90 days. Such a proportional change of CPO over time, likely reflecting native heart function recovery, may help to guide management of CS patients post-PVAD.

Temporary Mechanical Circulatory Support after Cardiac Surgery.

Postcardiotomy shock in the cardiac surgical patient is a highly morbid condition characterized by profound myocardial impairment and decreased systemic perfusion inadequate to meet end-organ metabolic demand. Postcardiotomy shock is associated with significant morbidity and mortality. Poor outcomes motivate the increased use of mechanical circulatory support (MCS) to restore perfusion in an effort to prevent multiorgan injury and improve patient survival. Despite growing acceptance and adoption of MCS for postcardiotomy shock, criteria for initiation, clinical management, and future areas of clinical investigation remain a topic of ongoing debate. This article seeks to (1) define critical cardiac dysfunction in the patient after cardiotomy, (2) provide an overview of commonly used MCS devices, and (3) summarize the relevant clinical experience for various MCS devices available in the literature, with additional recognition for the role of MCS as a part of a modified approach to the cardiac arrest algorithm in the cardiac surgical patient.

Effect of impeller rotational phase on the FDA blood pump velocity fields.

BACKGROUND: The Food and Drug Administration (FDA) blood pump is an open-source benchmark cardiovascular device introduced for validating computational and experimental performance analysis tools. The time-resolved velocity field for the whole impeller has not been established, as is undertaken in this particle image velocimetry (PIV) study. The level of instantaneous velocity fluctuations is important, to assess the flow-induced rotor vibrations which may contribute to the total blood damage. METHODS: To document these factors, time-resolved two-dimensional PIV experiments were performed that were precisely phase-locked with the impeller rotation angle. The velocity fields in the impeller and in the volute conformed with the previous single blade passage experiments of literature. RESULTS: Depending on the impeller orientation, present experiments showed that volute outlet nozzle flow can fluctuate up to 34% during impeller rotation, with a maximum standard experimental uncertainty of 2.2%. Likewise, the flow fields in each impeller passage also altered in average 33.5%. Considerably different vortex patterns were observed for different blade passages, with the largest vortical structures reaching an average core radii of 7 mm. The constant volute area employed in the FDA pump design contributes to the observed velocity imbalance, as illustrated in our velocity measurements. CONCLUSIONS: By introducing the impeller orientation parameter for the nozzle flow, this study considers the possible uncertainties influencing pump flow. Expanding the available literature data, analysis of inter-blade relative velocity fields is provided here for the first-time to the best of our knowledge. Consequently, our research fills a critical knowledge gap in the understanding of the flow dynamics of an important benchmark cardiovascular device. This study prompts the need for improved hydrodynamic designs and optimized devices to be used as benchmark test devices, to build more confidence and safety in future ventricular assist device performance assessment studies.

Treatment time limit for successful weaning from veno-arterial extracorporeal membrane oxygenation in cardiogenic shock.

AIMS: Knowing the upper time limit for successful weaning from temporary mechanical circulatory support in cardiogenic shock will help with decision-making regarding advanced heart failure (HF) therapy or considering withdrawal of care. The aim of this study was to investigate the association between the support duration and successful weaning from veno-arterial extracorporeal membrane oxygenation (VA-ECMO) in patients with cardiogenic shock. METHODS AND RESULTS: A retrospective single-centre cohort study was conducted between January 2013 and June 2023. It included 100 consecutive patients with cardiogenic shock who were treated with VA-ECMO. Patients with out-of-hospital cardiac arrest were excluded. The primary outcome was successful weaning from VA-ECMO (i.e., VA-ECMO decannulation and survival to discharge). The association between the length of support duration and the weaning success rate was analysed. Patients were divided into three groups according to ECMO support duration: Group A (≤7 days), Group B (8-14 days), and Group C (≥15 days). Multivariable logistic regression analysis was used to evaluate the impact of the length of support duration on successful weaning of VA-ECMO. The median age was 67 years, and 73% of study participants were male. The underlying aetiologies of cardiogenic shock were as follows: acute myocardial infarction, 50; fulminant myocarditis, 19; cardiomyopathy, 15; valvular heart disease, 8; and other, 8. Seventy-five patients (75%) were attempted to wean VA-ECMO, and 67 moved on to decannulation. In total, 43 (43%) patients were successfully weaned from VA-ECMO. The median length of ECMO support duration was 8 [3-15] days. Compared with those who underwent successful ECMO decannulation, those who did not had a significantly longer support duration of VA-ECMO (5 [3-9] days vs. 12 [3-22] days, P = 0.004). The weaning success rate was significantly higher in patients with short support duration; 58% (29/50), 40% (10/25), 16% (4/25) in Groups A, B, and C, respectively (P = 0.002). Overall, none of the patients supported for over 24 days (0/11) were successfully weaned from VA-ECMO. On multivariable logistic regression analysis, the length of support duration was independently associated with successful weaning after adjusting for age, sex, underlying aetiology, and left ventricular ejection fraction (odds ratio, 0.813 [per 3 days]; 95% confidence interval, 0.679-0.914; P = 0.025). CONCLUSIONS: Long support duration of VA-ECMO was significantly associated with a low rate of successful weaning in patients with cardiogenic shock. Patients who require VA-ECMO for over 1 week should start considering advanced HF therapy or withdrawal of care.

Mortality in Recipients of Durable Left Ventricular Assist Devices Undergoing Ventricular Tachycardia Ablation.

BACKGROUND: Left ventricular assist device (LVAD) recipients have a higher incidence of ventricular tachycardia (VT). However, the role of VT ablation in this population is not well-established. OBJECTIVES: This single-center retrospective cohort study sought to examine the impact of post-LVAD implant VT ablation on survival. METHODS: This retrospective study examined a cohort of patients that underwent LVAD implantation at Baylor St. Luke's Medical Center and Texas Heart Institute between January 2011 and January 2021. All-cause estimated mortality was compared across LVAD recipients based on the incidence of VT, timing of VT onset, and the occurrence and timing of VT ablation utilizing Kaplan-Meier survival analysis and Cox proportional hazards models. RESULTS: Post-implant VT occurred in 53% of 575 LVAD recipients. Higher mortality was seen among patients with post-implant VT within a year of implantation (HR: 1.62 [95% CI: 1.15-2.27]). Among this cohort, patients who were treated with a catheter ablation had superior survival compared with patients treated with medical therapy alone for the 45 months following VT onset (HR: 0.48 [95% CI: 0.26-0.89]). Moreover, performance of an ablation in this population aligned mortality rates with those who did not experience post-implant VT (HR: 1.18 [95% CI: 0.71-1.98]). CONCLUSIONS: VT occurrence within 1 year of LVAD implantation was associated with worse survival. However, performance of VT ablation in this population was correlated with improved survival compared with medical management alone. Among patients with refractory VT, catheter ablation aligned survival with other LVAD participants without post-implant VT. Catheter ablation of VT is associated with improved survival in LVAD recipients, but further prospective randomized studies are needed to compare VT ablation to medical management in LVAD recipients.

Re-imagining the future state of the ventricular assist device controller interface through human-centered design.

BACKGROUND: Ventricular assist devices (VADs) are effective therapy for patients with end-stage heart failure. Current VAD controllers offer improved interactivity, yet limitations of the visual, tactile, and auditory interface persist that impact patient experience and quality of life (QoL). This study explores how VAD controllers can be redesigned using a human-centered design approach to enhance the emotional and functional experience of the device for patients. METHODS: VAD patients (n = 21), caregivers (n = 4) and healthcare practitioners (n = 24) were interviewed to uncover design opportunities. From this, a series of realistic scenarios to design for emerged. A "design by analogy" method took inspiration from existing consumer products to ideate new functionality for the VAD wearable system, creating concepts for a controller interface and paired wearable device. An additional 15 patients and 2 caregivers were engaged to explore current VAD controller experiences and evaluate the future-state concepts. RESULTS: This research validated the need for increased automation and emergency functionality in VAD controllers, including remote monitoring of data, accurate communication of battery status, and automated medical alerts for critical device alarms. "Manage my health," "Feeling normal," "Social belonging," "Feeling safe," and "Sense of control" emerged as key patient concerns to be met by future VAD controller designs. CONCLUSIONS: The study demonstrated an innovative and relevant approach to improve usability of future VAD peripherals. By considering both emotional and functional perspectives in the design of lifesaving medical devices such as VADs, device manufacturers can uncover new opportunities to improve patient QoL through improved user experiences.

The Management of Cardiogenic Shock From Diagnosis to Devices: A Narrative Review.

Cardiogenic shock (CS) is a heterogenous syndrome broadly characterized by inadequate cardiac output leading to tissue hypoperfusion and multisystem organ dysfunction that carries an ongoing high mortality burden. The management of CS has advanced rapidly, especially with the incorporation of temporary mechanical circulatory support (tMCS) devices. A thorough understanding of how to approach a patient with CS and to select appropriate monitoring and treatment paradigms is essential in modern ICUs. Timely characterization of CS severity and hemodynamics is necessary to optimize outcomes, and this may be performed best by multidisciplinary shock-focused teams. In this article, we provide a review of CS aimed to inform both the cardiology-trained and non-cardiology-trained intensivist provider. We briefly describe the causes, pathophysiologic features, diagnosis, and severity staging of CS, focusing on gathering key information that is necessary for making management decisions. We go on to provide a more detailed review of CS management principles and practical applications, with a focus on tMCS. Medical management focuses on appropriate medication therapy to optimize perfusion-by enhancing contractility and minimizing afterload-and to facilitate decongestion. For more severe CS, or for patients with decompensating hemodynamic status despite medical therapy, initiation of the appropriate tMCS increasingly is common. We discuss the most common devices currently used for patients with CS-phenotyping patients as having left ventricular failure, right ventricular failure, or biventricular failure-and highlight key available data and particular points of consideration that inform tMCS device selection. Finally, we highlight core components of sedation and respiratory failure management for patients with CS.

Changes in waiting time, need for mechanical circulatory support and outcomes in paediatric heart transplant recipients.

AIMS: Heart transplantation is a well-established treatment for end-stage heart failure in paediatric patients, demonstrating excellent long-term outcomes. METHODS: This retrospective study analyses 35 years of data on 244 paediatric recipients (<18 years) at a single institution from 1986 to 2022. The analysis explores changes in diagnoses, survival, waiting times and mechanical circulatory support (MCS) over three decades (1991-2000, 2001-2010 and 2011-2020). RESULTS: Survival outcomes significantly improved over the study period, with 1-year survival rates increasing from 79.3% (1991-2000) to 92.3% (2011-2020, P = 0.041). The median overall survival was 18.0 years, and median conditional survival to 1 year post-transplant was 20.9 years. Survival differences were noted among age groups, with infants under 1 year of age experiencing higher early mortality, and adolescents (aged 11-17 years) facing increased long-term risks, possibly linked to adult donor characteristics. Waiting times for heart transplantation increased, especially for younger age groups (0-5 and 6-10 years), reflecting the growing demand for donor organs. The use of MCS, including ventricular assist devices (VAD), surged, with 67% of recipients in the most recent decade receiving pre-transplant VAD support. Importantly, despite prolonged waiting times and increased VAD use, overall survival continued to be favourable. CONCLUSIONS: Early and long-term results after paediatric heart transplantation have been continuously improving over the past decades. Despite an increased demand for donor organs and the growing reliance on VAD as bridge to transplantation, post-transplantation survival is not compromised.

Comparison of Intraoperative Blood Product Use During Heart Transplantation in Patients Bridged with Impella 5.5 versus Durable Left Ventricular Assist Devices.

OBJECTIVE: To determine if the intraoperative transfusion requirements differ based on the mechanical circulatory device used as a bridge to heart transplantation. DESIGN: A single-center retrospective analysis of intraoperative transfusion requirements in all patients undergoing heart or heart/kidney transplantation between November 2018 and July 2021 who were bridged with a temporary (Impella 5.5) or durable left ventricular assist device (LVAD). SETTING: A tertiary care hospital. PARTICIPANTS: Forty-three adult patients bridged to heart or heart/kidney transplantation with a temporary or durable LVAD between 2018 and 2021 INTERVENTIONS: Recording of baseline characteristics and intraoperative transfusion requirements, including packed red blood cells, fresh frozen plasma, cryoprecipitate, autologous blood salvage, and platelets. The difference in cardiopulmonary bypass times, intensive care unit length of stay, and the vasoactive inotrope score following transplantation were also recorded. MEASUREMENTS AND MAIN RESULTS: The primary outcome was the volume of blood products transfused intraoperatively. Patients who underwent bridge to transplantation using the Impella 5.5 had statistically significant lower median transfusions of cryoprecipitate (155 mL versus 200 mL, p = 0.015), autologous blood salvage (675 mL versus 1,125 mL, p ≤ 0.01), and platelets (412 mL versus 675 mL, p ≤ 0.01). Additionally, there was a trend toward lower transfusion of intraoperative packed red blood cells (4.5 units versus 6.5 units, p = 0.29) and fresh frozen plasma (675 mL versus 800 mL, p = 0.11), but these were not statistically significant. CONCLUSIONS: The results suggest a reduction in certain intraoperative transfusion requirements in patients undergoing heart transplantation bridged with the Impella 5.5 versus durable left ventricular assist device.

Early-stage Development of the CoRISMA Mechanical Circulatory Support (CMCS) System for Heart Failure Therapy.

PURPOSE: CoRISMA MCS Systems Inc (Hamden CT) is developing an innovative mechanical circulatory support system (CMCS) as a durable therapeutic option for heart failure (HF) patients. The CMCS system is comprised of an axial flow pump, non-contacting hydrodynamic bearings, and integrated DC motor designed to be fully implantable in a left atrial (LA) to aortic (Ao) configuration; this unloading strategy may be particularly beneficial for HF patients with preserved ejection fraction (HFpEF). The small (5.5 cm3), lightweight (20 g), and low power (5-7 W) device design should allow for a less invasive off-pump implant. We present early-stage engineering development and testing of the prototype CoRISMA pumps. METHODS: Computational fluid dynamics (CFD) modeling was performed to evaluate flow and shear in two impeller (3 blades, 0.5 mm thickness, 8.9 mm diameter, 0.15 mm gap, polished titanium) and diffusor (5 blades, polished titanium) candidate designs. Test apparatuses were custom built to expedite development of the impeller/diffuser designs and iteratively refine the CFD models. Two candidate impeller/diffusor designs were fabricated and tested in each of the two test apparatuses (n = 4 impeller/diffuser + test fixture configurations) in static mock flow loops (hydrodynamic H-Q curves, 3.5 cP glycerol solution at 37 °C), and in dynamic mock flow loops (hemodynamics, 3.5 cP glycerol solution at 37 °C) tuned to HF conditions (mean aortic pressure 50 mmHg, central venous pressure 15 mmHg, aortic flow 3.0 L/min, and heart rate 80 bpm). RESULTS: CFD predicted flows of 4.56 L/min and 4.82 L/min at 100 mmHg for impellers/diffusers 1 and 2, respectively. Impeller 2 required less torque to generate a 6% increase in fluidic flow, and the diffuser had a larger area of high pressure, indicative of lower friction, which likely contributed to the increased efficiency. Experimental testing for all four configurations in the static and dynamic mock loops met performance metrics as evidenced by generating 4.0-4.5 L/min flow against 70-76 mmHg pressure at 25,000 rpm and restoring hemodynamics in the dynamic mock flow loop (MAP = 80 mmHg, CVP = 0 mmHg, total flow = 5.5 L/min) from baseline simulated HF test conditions. CONCLUSION: These results demonstrate proof-of-concept of the early engineering design and performance of the prototype CoRISMA pumps. Engineering specifications, challenges observed, and proposed solutions for the next design iteration were identified for the continued development of an effective, reliable, and safe LA-to-Ao CMCS system for HF patients. Current design plans are underway for incorporating a wireless energy transfer system for communication and power, eliminating the need for and complications associated with an external driveline, to achieve a fully-implantable system.

The effect of high-dose selenium on mortality and postoperative organ dysfunction in post-cardiotomy cardiogenic shock patients supported with mechanical circulatory support - A post-hoc analysis of the SUSTAIN CSX trial.

PURPOSE: Cardiac surgery, post-cardiotomy cardiogenic shock (PCCS), and temporary mechanical circulatory support (tMCS) provoke substantial inflammation. We therefore investigated whether a selenium-based, anti-inflammatory strategy would benefit PCCS patients treated with tMCS in a post-hoc analysis of the sustain CSX trial. METHODS: Post-hoc analysis of patients receiving tMCS for PCCS in the Sustain CSX trial, which investigated the effects of high-dose selenium on postoperative organ dysfunction in cardiac surgery patients. PRIMARY OUTCOME: duration of tMCS therapy. SECONDARY OUTCOMES: postoperative organ dysfunction and 30-day mortality. RESULTS: Thirty-nine patients were treated with tMCS for PCCS. There was no difference in the median duration of tMCS between the selenium and the placebo group (3 days [IQR: 1-6] vs. 2 days [IQR: 1-7], p = 0.52). Median dialysis duration was longer in the selenium group (1.5 days [0-21.8] vs. 0 days [0-1.8], p = 0.048). There was no difference in 30-day mortality (53% vs. 41%, OR 1.44, 95% CI 0.32-6.47, p = 0.62). CONCLUSION: In this explorative study, a perioperative high-dose selenium-supplementation did not show beneficial effects on organ dysfunctions and mortality rates in patients with PCCS receiving tMCS.

Single center outcomes after temporary mechanical circulatory assist device prior to Heartmate 3 implantation - a retrospective cohort study.

Objectives. Temporary mechanical circulatory support (TMCS) has become a component in the therapeutic strategy for treatment of cardiogenic shock as a bridge-to-decision. TMCS can facilitate recovery of cardiopulmonary function, end-organ function, and potentially reduce the surgical risk of left ventricular assist device (LVAD) implantation. Despite the improvements of hemodynamics and end-organ function, post-LVAD operative morbidity might be increased in these high-risk patients. The aim of the study was to compare outcomes after Heartmate 3 (HM3) implantation in patients with and without TMCS prior to HM3 implant. Methods. In this retrospective cohort study of all HM3 patients in the period between November 2015 and October 2021, patients with and without prior TMCS were compared. Patients' demographics, baseline clinical characteristics, laboratory tests, intraoperative variables, postoperative outcomes, and adverse events were collected from patient records. Results. The TMCS group showed an improvement in hemodynamics prior to LVAD implantation. Median TMCS duration was 19.5 (14-26) days. However, the TMCS group were more coagulopathic, had more wound infections, neurological complications, and more patients were on dialysis compared with patient without TMCS prior to HM3 implantation. Survival four years after HM3 implantation was 80 and 82% in the TMCS (N = 22) and non-TMCS group (N = 41), respectively. Conclusion. Patients on TMCS had an acceptable short and long-term survival and comparable to patients receiving HM3 without prior TMCS. However, they had a more complicated postoperative course.