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The research aims to determine the effectiveness of torsional dampers with adaptive characteristics for crankshafts of piston internal combustion engines. The paper deals with the pressing issue of designing a torsional vibration damper for crankshafts of internal combustion engines, which can work efficiently in the entire operating range of speed variance. The standard approach to design the damper with constant characteristics implies one resonant operating mode, which in actual practice is not always justified. This fact decreases the operating efficiency, especially for the forced V-type engines. In order to determine the design parameters of dampers with adaptive characteristics, a multi-parameter optimization problem must be solved, which requires experimental validation. The work considers an approximate method, according to which the main parameters of the designed damper for different operating modes are determined. We obtained the general trend of changing the torsional damper characteristics by performing calculations for different engine operating modes. Based on these data, it is possible to determine the operating modes of the control mechanism. Comparing the efficiency of dampers with constant characteristics under the same modes allows validating the results’ adequacy. The scientific novelty lies in the developed method of modes determining torsional vibration damper parameters at changing speed and operating can help design new efficient forced internal combustion engines.

Objectives: Bridging from a temporary microaxial left ventricular assist device (tLVAD) to a durable left ventricular assist device (dLVAD) is playing an increasing role in the treatment of terminally ill patients with heart failure. Scant data exist about the best implant strategy. The goal of this study was to analyse differences in the dLVAD implant technique and effects on patient outcomes., Methods: Data from 341 patients (19 European centres) who underwent a bridge-to-bridge implant from tLVAD to dLVAD between January 2017 and October 2022 were retrospectively analysed. The outcomes of the different implant techniques with the patient on cardiopulmonary bypass, extracorporeal life support or tLVAD were compared., Results: A durable LVAD implant was performed employing cardiopulmonary bypass in 70% of cases (n = 238, group 1), extracorporeal life support in 11% (n = 38, group 2) and tLVAD in 19% (n = 65, group 3). Baseline characteristics showed no significant differences in age (P = 0.140), body mass index (P = 0.388), creatinine level (P = 0.659), the Model for End-Stage Liver Disease (MELD) score (P = 0.190) and rate of dialysis (P = 0.110). Group 3 had significantly fewer patients with preoperatively invasive ventilation and cardiopulmonary resuscitation before the tLVAD was implanted (P = 0.009 and P < 0.001 respectively). Concomitant procedures were performed more often in groups 1 and 2 compared to group 3 (24%, 37% and 5%, respectively, P < 0.001). The 30-day mortality data showed significantly better survival after an inverse probability of treatment weighting in group 3, but the 1-year mortality showed no significant differences among the groups (P = 0.012 and 0.581, respectively). Postoperative complications like the rate of right ventricular assist device (RVAD) implants or re-thoracotomy due to bleeding, postoperative respiratory failure and renal replacement therapy showed no significant differences among the groups. Freedom from the first adverse event like stroke, driveline infection or pump thrombosis during follow-up was not significantly different among the groups. Postoperative blood transfusions within 24 h were significantly higher in groups 1 and 2 compared to surgery on tLVAD support (P < 0.001 and P = 0.003, respectively)., Conclusions: In our analysis, the transition from tLVAD to dLVAD without further circulatory support did not show a difference in postoperative long-term survival, but a better 30-day survival was reported. The implant using only tLVAD showed a reduction in postoperative transfusion rates, without increasing the risk of postoperative stroke or pump thrombosis. In this small cohort study, our data support the hypothesis that a dLVAD implant on a tLVAD is a safe and feasible technique in selected patients., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Background: Stroke after durable left ventricular assist device (d-LVAD) implantation portends high mortality. The incidence of ischemic and hemorrhagic stroke and the impact on stroke outcomes of temporary mechanical circulatory support (tMCS) management among patients requiring bridge to d-LVAD with micro-axial flow-pump (mAFP, Abiomed) is unsettled., Methods: Consecutive patients, who underwent d-LVAD implantation after being bridged with mAFP at 19 institutions, were retrospectively included. The incidence of early ischemic and hemorrhagic stroke after d-LVAD implantation (<60 days) and association of pre-d-LVAD characteristics and peri-procedural management with a specific focus on tMCS strategies were studied., Results: Among 341 patients, who underwent d-LVAD implantation after mAFP implantation (male gender 83.6%, age 58 [48-65] years, mAFP 5.0/5.5 72.4%), the early ischemic stroke incidence was 10.8% and early hemorrhagic stroke 2.9%. The tMCS characteristics (type of mAFP device and access, support duration, upgrade from intra-aortic balloon pump, ECMELLA, ECMELLA at d-LVAD implantation, hemolysis, and bleeding) were not associated with ischemic stroke after d-LVAD implant. Conversely, the device model (mAFP 2.5/CP vs. mAFP 5.0/5.5: HR 5.6, 95%CI 1.4-22.7, p = 0.015), hemolysis on mAFP support (HR 10.5, 95% CI 1.3-85.3, p = 0.028) and ECMELLA at d-LVAD implantation (HR 5.0, 95% CI 1.4-18.7, p = 0.016) were associated with increased risk of hemorrhagic stroke after d-LVAD implantation. Both early ischemic (HR 2.7, 95% CI 1.9-4.5, p < 0.001) and hemorrhagic (HR 3.43, 95% CI 1.49-7.88, p = 0.004) stroke were associated with increased 1-year mortality., Conclusions: Among patients undergoing d-LVAD implantation following mAFP support, tMCS characteristics do not impact ischemic stroke occurrence, while several factors are associated with hemorrhagic stroke suggesting a proactive treatment target to reduce this complication., (© 2024 International Center for Artificial Organ and Transplantation (ICAOT) and Wiley Periodicals LLC.)

Background: The HeartMate 3 (HM 3; Abbott) left ventricular assist device (LVAD) has improved hemocompatibility-related adverse outcomes. In sporadic cases, external compression of the outflow graft causing obstruction (eOGO) can result from substance accumulation between the outflow graft and its bend relief. We sought to evaluate the prevalence, course, and clinical implications of eOGO in an international study., Methods: A multicenter retrospective analysis of HM 3 LVADs implanted between November 2014 and April 2021 (n = 2108) was conducted across 17 cardiac centers in 8 countries. We defined eOGO as obstruction >25% in the cross-sectional area in imaging (percutaneous angiography, computed tomography, or intravascular ultrasound). The prevalence and annual incidence were calculated. Serious adverse events and outcomes (death, transplantation, or device exchange) were analyzed for eOGO cases., Results: Of 2108 patients, 62 were diagnosed with eOGO at a median LVAD support duration of 953 (interquartile range, 600-1267) days. The prevalence of eOGO was 3.0% and the incidence at 1, 2, 3, 4, and 5 years of support was 0.6%, 2.8%, 4.0%, 5.2%, and 9.1%, respectively. Of 62 patients, 9 were observed, 27 underwent surgical revision, 15 underwent percutaneous stent implantation, 8 received a heart transplant, and 2 died before intervention. One patient underwent surgical revision and later stent implantation. The mortality with therapeutic intervention was 9/53 (17.0%)., Conclusions: Although uncommon, HM 3 LVAD-supported patients might develop eOGO with an increasing incidence after 1 year of support. Although engineering efforts to reduce this complication are under way, clinicians must maintain a focus on early detection and remain vigilant., (Copyright © 2022 The American Association for Thoracic Surgery. All rights reserved.)

Background: Takotsubo syndrome is, by definition, a reversible form of acute heart failure. If cardiac output is severely reduced, Takotsubo syndrome can cause cardiogenic shock, and mechanical circulatory support can serve as a bridge to recovery. To date, there are no recommendations on when to use mechanical circulatory support and on which device is particularly effective in this context. Our aim was to determine the best treatment strategy., Methods: A systematic literature research and analysis of individual patient data was performed in MEDLINE/PubMed according to PRISMA guidelines. Our research considered original works published until 31 July 2023., Results: A total of 93 publications that met the inclusion criteria were identified, providing individual data from 124 patients. Of these, 62 (50%) were treated with veno-arterial extracorporeal life support (va-ECLS), and 44 (35.5%) received a microaxial left ventricular assist device (Impella). Eighteen patients received an Impella CP and twenty-one an Impella 2.5. An intra-aortic balloon pump (IABP) without other devices was used in only 13 patients (10.5%), while other devices (BiVAD or Tandem Heart) were used in 5 patients (4%). The median initial left ventricular ejection fraction was 20%, with no difference between the four device groups except for the IABP group, which was less affected by cardiac output failure ( p = 0.015). The overall survival was 86.3%. Compared to the other groups, the time to cardiac recovery was shorter with Impella ( p < 0.001)., Conclusions: Though the Impella treatment is new, our analysis may show a significant benefit of Impella compared to other MCS strategies for cardiogenic shock in Takotsubo syndrome.

Ventricular septal defect (VSD) is a rare but severe complication of myocardial infarction (MI). Temporary mechanical circulatory support (MCS) can be used as a bridge to VSD closure, heart transplantation, or ventricular assist device. We describe the use of Impella device in this context based on a multicenter European retrospective registry (17 centers responded). Twenty-eight post-MI VSD patients were included (Impella device were 2.5 for 1 patient, CP for 20, 5.0 for 5, and unknown for 2). All patients were in cardiogenic shock with multiple organ failure (SAPS II 41 [interquantile range {IQR} = 27-53], lactate 4.0 ± 3.5 mmol/L) and catecholamine support (dobutamine 55% and norepinephrine 96%). Additional temporary MCS was used in 14 patients (50%), mainly extracorporeal life support (ECLS) (n = 9, 32%). Severe bleedings were frequent (50%). In-hospital and 1 year mortalities were 75%. Ventricular septal defect management was surgical for 36% of patients, percutaneous for 21%, and conservative for 43%. Only surgically managed patients survived (70% in-hospital survival). Type and combination of temporary MCS used were not associated with mortality (Impella alone or in combination with intra-aortic balloon pump [IABP] or ECLS, p = 0.84). Impella use in patients with post-MI VSD is feasible but larger prospective registries are necessary to further elucidate potential benefits of left ventricular unloading in this setting., Competing Interests: Disclosure: C.D. has received personal fees from Abott and Abiomed outside the submitted work. G.L. has received proctor, orator and consulting fees from Abbott SA. E.V.P. has received institutional fees from Abott, Medtronic, and Abiomed outside the submitted work. J.L. has received research funds that were paid to the institution from Shockwave Medical Inc. and from Abiomed, and payment or honoraria from AstraZeneca and Boston Scientific, outside the submitted work. J.M. has received personal fees from Abiomed outside the submitted work. P.L. has received personal fees from Abiomed outside the submitted work. N.M. has received personal fees from Edwards Lifesciences, Medtronic, Biotronik, Novartis, Sanofi Genzyme, AstraZeneca, Pfizer, Bayer, Abbott, Abiomed, and Boston Scientific outside the submitted work. The other authors have no conflicts of interest to report., (Copyright © ASAIO 2023.)

Objectives: Cardiogenic shock (CS) can occur in patients with Takotsubo syndrome (TTS). As TTS has received increasing attention and has been more closely researched, several aspects of the pathogenesis have been identified, particularly that an excessive release of catecholamines plays an important role. Nevertheless, evidence on specific therapy concepts is still lacking. As a result, TTS with severe hemodynamic instability and low cardiac output creates unique challenges, and mechanical circulatory support is needed with as few inotropic drugs as possible., Methods: We present a 77-year-old female patient who underwent minimally invasive surgical mitral valve replacement. After an uneventful course, the patient developed acute heart failure eleven days after surgery. Transthoracic echocardiography (TTE) revealed a new onset of TTS. The patient needed left ventricular venting and full haemodynamic flow. We successfully implanted a microaxial left ventricular assist device (Impella 5.5) using the transaxillary approach. The haemodynamic situation stabilised immediately. The patient was weaned and the Impella 5.5 was explanted after five days., Conclusion: We present the first-in-man implantation of a transaxillary Impella 5.5 in a patient with TTS. The patient benefitted from Impella 5.5 therapy with full haemodynamic support and venting of the left ventricle., (© 2023. The Author(s).)

Transaxillary implantation of a temporary microaxial left ventricular assist device in patients suffering from cardiogenic shock is an established technique. We present a 77-year-old female patient with severe mitral regurgitation. She underwent minimally invasive surgical mitral valve replacement. After an uneventful postoperative course, the patient developed acute heart failure on the 11th postoperative day. Transthoracic echocardiography revealed new onset of Takotsubo cardiomyopathy with a severely decreased left ventricular ejection fraction. Implantation of a microaxial flow pump for left ventricular decompression was scheduled. Preoperative computed tomography revealed a rectangular course of the right subclavian artery. To advance the Impella, we employed an introducer fitted over the guidewire behind the Impella device as a 'cue stick' to move the rigid part of the pump forward to overcome the kinking using a 'shuffleboard technique'. The haemodynamic situation stabilized immediately after implantation. The Impella 5.5 was successfully weaned after 6 days of support. In the event of (rectangular) kinking of the subclavian artery, the 'shuffleboard technique' can be used for the successful positioning of the pump., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery.)

Background: Impella 5.0 and 5.5 (summarized as Impella 5+) are microaxial, catheter-based left ventricular assist devices (LVAD) that are implanted via a vascular graft sutured to the axillary artery and provide blood flow of up to 5.5 liter/min. This study aims to investigate the incidence of long-term complications following circulatory support with Impella 5+., Methods: A single-center retrospective analysis of 203 consecutive adult patients treated between January 2017 and September 2021 with a surgically implanted Impella 5.0 or 5.5 via a vascular graft sutured to the axillary artery., Results: The median Impella support duration was 8 days. Of 203 patients, 78 (38.4%) died while on temporary mechanical circulatory support. Fifty-five (27.1%) were successfully weaned from Impella 5+ and 70 (34.5%) were bridged to a durable LVAD with a median follow-up time of 232 (IQR 68.5, 597) days after Impella 5+ explantation. In 119 of these patients, the Impella was explanted and the vascular graft was shortened, ligated, and pushed under the pectoralis muscle; in 6 patients early graft infection prompted complete graft removal during explantation. In addition, 13 patients (10.9%) developed a late-onset graft infection after a median of 86 days, requiring complete (n = 10) or partial (n = 2) explantation of the retained graft. In 1 patient, the graft infection was successfully treated by conservative therapy. Our analysis identified no specific risk factors for graft infections. Of the 203 patients, 5 (2.5%) developed a brachial plexus injury resulting in neurological dysfunction., Conclusions: In 10.9% of patients, retaining the vascular graft was complicated by a late graft infection. Complete explantation of the graft prosthesis may decrease the infection rate, but may in turn increase the risk of brachial plexus injury. On the other hand, this method offers the possibility of bedside explantation., (Copyright © 2022 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)

Background: A growing proportion of transplant donors and recipients have a history of COVID-19 infection. This study sought to characterize clinical practice after recipient or donor COVID-19 infection., Methods: An online survey was distributed to heart transplant clinicians through a professional society message board and social media. Responses were collected between September 29 and November 5, 2021., Results: There were 222 health care professionals (68% transplant cardiologists, 22% transplant surgeons, 10% other) across diverse geographic regions who completed the survey. While there was significant variation in donor acceptance, as it relates to past and current COVID-19 infection, the respondents were fairly cautious: 28% would not typically accept a donor with a history of COVID-19 regardless of the infection course and > 80% would not accept donors who had evidence of myocardial dysfunction during past COVID-19 infection, or who died of COVID-19 or its complications. The timing of candidate reactivation on the waiting list after COVID-19 infection also varied and often diverged from scenarios addressed by social guidelines. Eighty-one percent of the respondents felt COVID-19 vaccine should be mandatory before transplant, but this rate varied by geographic region., Conclusion: Our results reflect evolving experience of the heart transplant field at a time of lack of high-quality evidence. In the absence of longer-term outcome data for donors and transplant candidates with history of COVID-19 infection, clinicians remain cautious; however, this approach will likely need to be refined as an increasing proportion of the population will continue to be infected with COVID-19., (© 2022 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Cardiopulmonary bypass (CPB) during left ventricular assist device (LVAD) implantation provides circulatory support and allows for safe inspection of the left ventricle (LV), whereas circulatory support by veno-arterial extracorporeal life support (va-ECLS) or off-pump implantation may reduce postoperative bleeding and inflammatory response., Methods: Retrospective analysis of 616 consecutive adult patients who received an LVAD via median sternotomy between January 1, 2015 and December 31, 2019. All patients undergoing concomitant intracardiac procedures other than closure of persistent foramen ovale or atrial septal defect and redo surgeries were excluded from the analysis. The remaining patients (n = 222) were divided into two groups and 1:1 propensity score-matched regarding preoperative parameters: patients who underwent LVAD implantation with LV inspection employing CPB (CPB group, n = 62) and without LV inspection on va-ECLS or off-pump (non-CPB group, n = 62)., Results: The groups were well balanced with regard to preoperative baseline characteristics (standard difference <0.1). Patients in the CPB group required more blood transfusions (median 2 vs. 0 units, p = 0.031) during surgery and in the first 24 h afterwards. The median intensive care unit stay was longer in the CPB group (18 vs. 11 days, p = 0.021). The CPB group showed an absence of perioperative stroke and a smaller number of events per patient-year for postoperative ischemic stroke (0.02 vs. 0.12, p = 0.003). 30-day survival (87% vs. 87.1%) and 1-year survival (80.3% vs. 74%) were similar in both groups (p = 0.78)., Conclusion: Visual LV inspection on CPB may reduce the risk of postoperative ischemic stroke. Despite the negative effects of employing CPB in lieu of other intraoperative strategies, survival was similar in both groups., (© 2021 The Authors. Artificial Organs published by International Center for Artificial Organ and Transplantation (ICAOT) and Wiley Periodicals LLC.)

Objectives: Myocardial recovery allows for left ventricular assist device (LVAD) explantations after long-term support. Several surgical approaches, including interventional decommissioning, off-pump explantation using a custom-made plug and complete LVAD removal through redo sternotomy, have been described. We present the results from an evaluation of the long-term follow-up of patients who received a titanium sintered plug after LVAD explantation., Methods: We performed a retrospective, European, multicentre analysis of patients who received a titanium sintered plug to seal the apical fixation ring after LVAD explantation. Data were collected from a questionnaire that included demographics, procedural details and follow-up information., Results: Out of 54 contacted centres in 12 countries (n = 179 patients), a total of 68 patients were successfully included in the study. The median follow-up was 34 months (interquartile range: 17-58.5 months); 57 (84%) patients had >1-year follow-up. At the time of the last follow-up, 55 (81%) patients were alive, with a Kaplan-Meier 1-year survival of 90.1% (95% confidence interval: 84.0-98.1%) and a 5-year survival of 80.0% (95% confidence interval: 68.4-92.9%). One patient (1.5%) developed a plug infection originating from an infected part of the incorporated driveline and, after complete removal, is currently in good condition. No postoperative stroke has been reported after plug implantation., Conclusions: In this European multicentre study, the use of a custom-made titanium plug to close the apical fixation ring after LVAD explantation resulted in a low incidence of plug-related complications. With the volume of patients undergoing LVAD explantations after myocardial recovery increasing, the plug has evolved as a simple alternative to more invasive device explantation procedures or decommissioning with a high risk for infection of the remaining system or stroke., (© The Author(s) 2021. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery.)

Background and Methods: Microaxial left ventricular assist devices are used increasingly for treating cardiogenic shock. We compared the short-term outcome of patients supported with different microaxial devices for cardiogenic shock. A retrospective propensity score-adjusted analysis was performed in cardiogenic shock patients treated with either the Impella CP (n = 64) or the Impella 5.0/5.5 (n = 62) at two tertiary cardiac care centers between 1/14 and 12/19., Results: Patients in the Impella CP group were significantly older (69.6 ± 10.7 vs. 58.7 ± 11.9 years, p = .001), more likely in INTERMACS profile 1 (76.6% vs. 50%, p = .003) and post-C-reactive protein (CPR) (36% vs. 13%, p = .006). The median support time was 2.0 days [0.0, 5.3] in the CP group vs. 8.5 days [4.3, 15.8] in the 5.0/5.5 group (p < .001). The unadjusted 30-day survival was significantly higher in the Impella 5.0/5.5 group (58% vs. 36%, p = .021, odds ratio [OR] for 30-day survival on Impella 5.0/5.5 was 3.68 [95% confidence interval [CI]: [1.46-9.90]], p = .0072). After adjustment, the 30-day survival was similar for both devices (OR: 1.23, 95% CI: [0.34-4.18], p = .744). Lactate levels above 8 mmol/L and preoperative CPR were associated with a significant mortality increase in both cohorts (OR: 10.7, 95% CI: [3.45-47.34], p < .001; OR: 13.2, 95% CI: [4.28-57.89], p < .001, respectively)., Conclusion: Both Impella devices offer a similar effect with regard to survival in cardiogenic shock patients. Preoperative CPR or lactate levels exceeding 8 mmol/L immediately before implantation have a poor prognosis on Impella CP and Impella 5.0/5.5., (© 2021 The Authors. Journal of Cardiac Surgery Published by Wiley Periodicals LLC.)

The coronavirus disease 2019 (COVID-19) pandemic has potentiated the need for implementation of strict safety measures in the medical care of surgical patients - and especially in cardiac surgery patients, who are at a higher risk of COVID-19-associated morbidity and mortality. Such measures not only require minimization of patients' exposure to COVID-19 but also careful balancing of the risks of postponing nonemergent surgical procedures and providing appropriate and timely surgical care. We provide an overview of current evidence for preoperative strategies used in cardiac surgery patients, including risk stratification, telemedicine, logistical challenges during inpatient care, appropriate screening capacity, and decision-making on when to safely operate on COVID-19 patients. Further, we focus on perioperative measures such as safe operating room management and address the dilemma over when to perform cardiovascular surgical procedures in patients at risk., Competing Interests: Declaration of competing interest J. C. Schefold declares that the Department of Intensive Care Medicine, Inselspital, Bern, has received research or other grants from (full departmental disclosure): Orion Pharma, Abbott Nutrition International, B. Braun Medical, CSEM, Edwards Lifesciences Services, Kenta Biotech, Maquet, Nestle, Pierre Fabre Pharma, Pfizer, Bard Medica, Abbott, Anandic Medical Systems, Pan Gas Healthcare, Bracco, Hamilton Medical, Fresenius Kabi, Getinge Group Maquet, Dräger, Teleflex Medical, GlaxoSmithKline, Merck Sharp and Dohme, Eli Lilly and Company, Baxter, Astellas, AstraZeneca, CSL Behring, Novartis, Covidien, Hemotune, Phagenesis, and Nycomed outside the submitted work. The money was paid into departmental funds; and all other authors reported no conflicts of interest., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objectives: The HeartWare HVAD (HW) and the HeartMate3 (HM3) are presently the most commonly used continuous-flow left ventricular assist devices worldwide. We compared the outcomes of patients supported with either of these 2 devices based on data from the EUROMACS (European Registry for Patients with Mechanical Circulatory Support)., Methods: A retrospective analysis of the survival and complications profile in propensity score-matched adult patients enrolled in the EUROMACS between 01 January 2016 and 01 September 2020 and supported with either an HW or HM3. Matching included demographic parameters, severity of cardiogenic shock and risk-modifying end-organ parameters that impact long-term survival. Survival on device and major postoperative adverse events were analysed., Results: Following 1:1 propensity score matching, each group consisted of 361 patients. Patients were well balanced (<0.1 standardized mean difference). The median follow-up was similar in both groups [396 (interquartile range (IQR) 112-771) days for HW and 376 (IQR 100-816) days for HM3]. The 2-year survival was similar in both groups [HW: 61% 95% confidence interval (CI) (56-67%) vs HM3: 68% 95% CI (63-73%) (stratified hazard ratio for mortality: 1.13 95% CI (0.83-1.54), P = 0.435].The cumulative incidence for combined major adverse events and unexpected readmissions was similar in both groups [subdistribution hazard ratio (SHR) 1.0 (0.84-1.21), P = 0.96]. Patients in the HW group demonstrated a higher risk of device malfunction [SHR 2.44 (1.45-3.71), P < 0.001], neurological dysfunction [SHR 1.29 (1.02-1.61), P = 0.032] and intracranial bleeding [SHR 1.76 (1.13-2.70), P = 0.012]., Conclusions: Mid-term survival in both groups was similar in a propensity-matched analysis. The risk of device malfunction, neurological dysfunction and intracranial bleeding was significantly higher in HW patients., (© The Author(s) 2021. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Background: Significant right ventricular failure (RVF) complicating left ventricular assist device (LVAD) placement has been reported at 10-30%. Although primarily indicated for left ventricular failure, ventricular assist devices (VADs) have become utilized in a biventricular setup to combat right ventricular failure (RVF) following LVAD implantation. With the advent of continuous-flow LVADs (CF-LVADs) superseding their pulsatile predecessors, the shift towards CF-biventricular assist devices (CF-BiVADs) come with the prospect of improved outcomes over previous pulsatile BiVADs. We aim to review the literature and determine the outcomes of CF-BiVAD recipients., Methods: A systematic review was performed to determine the outcomes of CF-BiVADs. Pre-operative demographics and device configuration data was collected. Primary outcomes evaluated were short-term survival, long-term survival, duration of support, and survival to transplant. Secondary outcomes evaluated included intensive care unit (ICU) and hospital length of stay (ICU-LOS and HLOS, respectively), pump thrombosis, pump exchange. Median and interquartile range was reported where appropriate. A major limitation was the likely overlap of cohorts across publications, which may have contributed to some selection bias., Results: Of 1,282 screened, 12 publications were evaluated. Sample size ranged from 4 to 93 CF-BiVAD recipients, and follow-up ranged from 6 to 24 months. Mean age ranged from 34 to 52 years old. Forty-five percent of CF-BiVADs had right atrial (RA-) inflow cannulation, with the remaining being right ventricular (RV). Thirty-day survival was a median of 90% (IQR 82-97.8%) and 12-month survival was a median of 58.5% (IQR 47.5-62%). Where reported, rate of pump thrombosis (predominantly the right VAD) was a median of 31% (IQR 14-36%), although pump exchange was only 9% (IQR 1.5-12.5%)., Conclusions: RVF post-LVAD implantation is a high morbidity and mortality complication. There is no on-label continuous-flow RVAD currently available. Thus, the modifications of LVADs for right ventricular support to combat pump thrombosis has resulted in various techniques. BiVAD recipients are predominantly transplant candidates, and complications of pump thrombosis and driveline infection whilst on wait-list are of great consequence. This study demonstrates the need for an on-label CF-BiVAD., Competing Interests: Conflicts of Interest: The authors have no conflicts of interest to declare., (2021 Annals of Cardiothoracic Surgery. All rights reserved.)

The handling of left ventricular assist devices (LVADs) can be challenging for patients and requires appropriate training. The devices' usability impacts patients' safety and quality of life. In this study, an eye tracking supported human factors testing was performed to reveal problems during use and test the trainings' effectiveness. In total 32 HeartWare HVAD patients (including 6 pre-VAD patients) and 3 technical experts as control group performed a battery change (BC) and a controller change (CC) as an everyday and emergency scenario on a training device. By tracking the patients' gaze point, task duration and pump-off time were evaluated. Patients with LVAD support ≥1 year showed significantly shorter BC task duration than patients with LVAD support <1 year (p = 0.008). In contrast their CC task duration (p = 0.002) and pump-off times (median = 12.35 s) were higher than for LVAD support patients <1 year (median = 5.3 s) with p = 0.001. The shorter BC task duration for patients with LVAD support ≥1 year indicate that with time patients establish routines and gain confidence using their device. The opposite effect was found for CC task duration and pump-off times. This implies the need for intermittent re-training of less frequent tasks to increase patients' safety.

Outflow graft obstruction in left ventricular assist devices (LVADs) is a rare complication whose clinical presentation may be subtle. We present six cases of outflow graft obstruction in patients on HeartMate 3 LVAD detected between 648 and 1,222 days on support. Detection principles are described and treatment strategies discussed. Three patients were successfully managed with stents, one underwent surgical revision, one patient died despite emergency treatment, and the last patient without symptoms was listed for heart transplantation., (Copyright © ASAIO 2020.)

Implantation of a left ventricular assist device (LVAD) is an established treatment in end-stage heart failure. The longevity of LVAD support systems remains uncertain to a great extent because patients usually undergo transplantation, are weaned or die while on support before the maximum service life of these pumps is reached. We report about the hitherto longest published and still ongoing LVAD support of a 65 year old patient who received an Incor LVAD (Berlin Heart, Berlin, Germany, produced 2002-2018) 13 years ago. After pump exchange due to driveline damage, the patients were discharged home.

Aims: Sufficient myocardial recovery with the subsequent explantation of a left ventricular assist device (LVAD) occurs in approximately 1-2% of the cases. However, follow-up data about this condition are scarcely available in the literature. This study aimed to report the long-term outcomes and clinical management following LVAD explantation., Methods and Results: An analysis of the European Registry for Patients with Mechanical Circulatory Support was performed to identify all adult patients with myocardial recovery and successful explantation. Pre-implant characteristics were retrieved and compared with the non-recovery patients. The follow-up data after explantation were collected via a questionnaire. A Kaplan-Meier analysis for freedom of the composite endpoint of death, heart transplantation, LVAD reimplantion, or heart failure (HF) relapse was conducted. A total of 45 (1.4%) cases with myocardial recovery resulting in successful LVAD explantation were identified. Compared with those who did not experience myocardial recovery, the explanted patients were younger (44 vs. 56 years, P < 0.001), had a shorter duration of cardiac disease (P < 0.001), and were less likely to have ischaemic cardiomyopathy (9% vs. 41.8%, P < 0.001). Follow-up after explantation could be acquired in 28 (62%) cases. The median age at LVAD implantation was 43 years (inter-quartile range: 29-52), and 23 (82%) were male. Baseline left ventricular ejection fraction was 18% (inter-quartile range: 10-20%), and 60.7% of the patients had Interagency Registry for Mechanically Assisted Circulatory Support Profile 1 or 2. Aetiologies of HF were dilated cardiomyopathy in 36%, myocarditis in 32%, and ischaemic in 14% of the patients, and 18% had miscellaneous aetiologies. The devices implanted were HeartMate II in 14 (50%), HVAD in 11 (39%), HeartMate 3 in 2 (7%), and 1 unknown with a median duration of support of 410 days (range: 59-1286). The median follow-up after explantation was 26 months (range 0.3-73 months), and 82% of the patients were in New York Heart Association Class I or II. Beta-blockers were prescribed to 85%, angiotensin-converting enzyme inhibitors to 71%, and loop diuretics to 50% of the patients, respectively. Freedom from the composite endpoint was 100% after 30 days and 88% after 2 years., Conclusions: The survival after LVAD explantation is excellent without the need for heart transplantation or LVAD reimplantation. Only a minority of the patients suffer from a relapse of significant HF., (© 2020 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.)

Left ventricular assist device-associated infections represent a major complication during long-term support. Driveline exit site infections harbour the risk of ascending into the pump, causing deep-seated infections. We report on the successful treatment of a chronic recurrent left ventricular assist device pump-associated infection by the local application of bacteriophages as adjunct to standard surgical and antimicrobial treatment., (© The Author(s) 2019. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Objectives: Pump thrombosis (PT) and thromboembolic events (TEs) remain major adverse events in left ventricular assist device (LVAD) therapy at an annual rate of 6-8% supported with the HeartWare HVAD and HeartMate II. PT and TEs are multifactorial events. Understanding the predisposing risk factors for PT and TE is paramount to define preventive strategies. Preoperative atrial fibrillation (AF) is considered a significant and potentially modifiable risk factor. This study investigates whether LVAD patients with AF exhibit a higher rate of PT and TE than those in sinus rhythm (SR)., Methods: We evaluated medical records of consecutive patients who underwent implantation of the HeartMate II (n = 195; 25.4%) and HeartWare HVAD (n = 574; 74.6%) at our institution between 2006 and 2015. Only visually confirmed PT was included in the study. TE was defined as any peripheral embolism or cerebral embolism according to the INTERMACS definitions., Results: SR was documented preoperatively in 211 patients (SR group) and AF in 558 patients (AF group). The median duration of support was 0.78 years in the AF group and 1.03 years in the SR group. The mean age was 60.27 years in the AF group and 52.04 years in the SR group. In the AF group, 83.0% of the patients were male, compared to 77.3% in the SR group. The cumulative incidence of PT in the SR group was 2.5% [95% confidence interval (CI) 0.3-4.7%] after 1 year and 5.7% (95% CI 2.2-9.2%) after 2 years, and in the AF group 4.9% (95% CI 3.0-6.7%) and 7.8% (95% CI 5.4-10.2%), respectively (P = 0.129). TEs were recorded in the SR group in 4.4% (95% CI 1.6-7.2%) after 1 year and in 6.3% (95% CI 2.8-9.8%) after 2 years, and occurred after a median support time of 214 days (range 120-768). In the AF group, the cumulative incidence was 8.4% (95% CI 6.0-10.7%) and 10.7% (95% CI 8.0-13.4%), respectively, after a median support time of 116 days (range 37-375), P-value = 0.163. In the multivariate analysis, event-free survival was not influenced by the preoperative SR [hazard ratio (HR) 0.86, 95% CI 0.68-1.1; P = 0.19]., Conclusions: Our study showed that the preoperative rhythm has no impact on survival, PT and TEs despite different preoperative risk factor profiles in the AF and SR group. Thus, the effect of a maze procedure, catheter ablation or left atrial appendage closure on PT and TE's for AF patients during LVAD implantation is questionable. However, to obtain a definitive answer, a prospective study would be of value., (© The Author(s) 2019. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Long-term mechanical circulatory support (LT-MCS) is an important treatment modality for patients with severe heart failure. Different devices are available, and many-sometimes contradictory-observations regarding patient selection, surgical techniques, perioperative management and follow-up have been published. With the growing expertise in this field, the European Association for Cardio-Thoracic Surgery (EACTS) recognized a need for a structured multidisciplinary consensus about the approach to patients with LT-MCS. However, the evidence published so far is insufficient to allow for generation of meaningful guidelines complying with EACTS requirements. Instead, the EACTS presents an expert opinion in the LT-MCS field. This expert opinion addresses patient evaluation and preoperative optimization as well as management of cardiac and non-cardiac comorbidities. Further, extensive operative implantation techniques are summarized and evaluated by leading experts, depending on both patient characteristics and device selection. The faculty recognized that postoperative management is multidisciplinary and includes aspects of intensive care unit stay, rehabilitation, ambulatory care, myocardial recovery and end-of-life care and mirrored this fact in this paper. Additionally, the opinions of experts on diagnosis and management of adverse events including bleeding, cerebrovascular accidents and device malfunction are presented. In this expert consensus, the evidence for the complete management from patient selection to end-of-life care is carefully reviewed with the aim of guiding clinicians in optimizing management of patients considered for or supported by an LT-MCS device., (© The Author(s) 2019. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery.)

Aims: Haemodynamic load induces cardiac remodelling via mechano-transduction pathways, which can further trigger inflammatory responses. We hypothesized that particularly in an inflammatory disorder such as myocarditis, a therapeutic strategy is required which, in addition to providing adequate circulatory support, unloads the left ventricle, decreases cardiac wall stress, and mitigates inflammatory responses., Methods and Results: Axial flow pumps such as the Impella systems comply with these requirements. Here, we report a potential mode-of-action of prolonged Impella support (PROPELLA concept) in fulminant myocarditis, including a decrease in cardiac immune cell presence, and integrin α1, α5, α6, α10 and β6 expression during unloading., Conclusion: PROPELLA may provide benefits beyond its primary function of mechanical circulatory support in the form of additional disease-altering effects, which may contribute to enhanced myocardial recovery/remission in patients with chronic fulminant myocarditis., (© The Author(s) 2019. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Mechanical circulatory support (MCS) is often required to stabilize patients with acute fulminant myocarditis with cardiogenic shock. This review gives an overview of the successful use of left-sided Impella in the setting of fulminant myocarditis and cardiogenic shock as the sole means of MCS as well as in combination with right ventricular (RV) support devices including extracorporeal life support (ECLS) (ECMELLA) or an Impella RP (BI-PELLA). It further provides evidence from endomyocardial biopsies that in addition to giving adequate support, LV unloading by Impella exhibits disease-modifying effects important for myocardial recovery (i.e., bridge-to-recovery) achieved by this newly termed "prolonged Impella" (PROPELLA) concept in which LV-IMPELLA 5.0, implanted via an axillary approach, provides support in awake, mobilized patients for several weeks. Finally, this review addresses the question of how to define the appropriate time point for weaning strategies and for changing or discontinuing unloading in fulminant myocarditis.

Significant right ventricular failure accompanying left ventricular failure was treated by implantation of the fully magnetically levitated centrifugal HeartMate 3 ventricular assist device as biventricular (BiVAD) support in 14 patients at 6 medical centers worldwide. The clinical details of this first multicenter experience are presented. Nine of these patients (64%) were alive as of January 1, 2018. Eight of the 9 have continued on BiVAD support for 95 to 636 (mean 266) days: 7 at home, and 1 successfully transplanted after 98 days of support., (Copyright © 2018 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)