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Hybride Testkreisläufe (HTK) stellen eine verbreitete Plattform für präklinische Untersuchungen von Blutpumpen dar. Dennoch sind herkömmliche Testkreisläufe bisher nicht in der Lage realistische hämodynamische Bedingungen zu reproduzieren, ohne dass zusätzliche Blutschädigung durch verwendete Komponenten entsteht. Dies beschränkt in-vitro Hämokompatibilitätsuntersuchungen von Blutpumpen auf statische Experimente, die die klinische Anwendung nicht realistisch wiedergeben. Das Ziel dieser Arbeit ist die Entwicklung eines atraumatischen Testkreislaufs, auf der Grundlage eines Hardware-in-the-Loop Konzeptes, um in-vitro Hämokompatibilitätsbetrachtungen unter realistischen hämodynamischen Bedingungen zu ermöglichen. Dieser neuartige atraumatische Testkreislauf ist für eine geringe Blutmenge von 450±50mL ausgelegt, wobei zwei Reservoire, Schlauchelemente und die zu untersuchende Blutpumpe die einzigen Komponenten mit direktem Blutkontakt darstellen. Diese Designmaßnahmen orientieren sich an aktuellen Standards der American Society for Testing and Materials. Das neue Hardware-Design erfordert eine fortschrittliche Regelungsstrategie um die Drücke und Füllstände des Systems zu regeln, zugehörige Referenzdrücke werden dabei auf der Basis der aktuellen Unterstützung durch die Blutpumpe durch ein Modell des kardiovaskulären Systems berechnet. In diesem Zusammenhang wird eine entkoppelnde nichtlineare Regelungsstrategie für die Systemdrücke entworfen, um internen Kopplungseffekten entgegenzuwirken und eine hohe Regelgenauigkeit sicherzustellen. Die Regelungsstrategie basiert auf der Methode der globalen Linearisierung und wird durch einen Regelungsansatz für die Füllstandshöhe der Reservoirs ergänzt. Mit dem atraumatischen Design ist die Füllstandshöhe periodisch nicht regelbar. Diese Problematik wird mit Hilfe eines Optimierungsproblems adressiert, woraus eine Regeltrajektorie resultiert, die den Füllstand bei minimaler Aktuatorbetätigung sicher innerhalb der Randbedingungen führt. Um die Genauigkeit des neuen HTKs zu evaluieren werden typische hämodynamische Zustände von Patienten die mit einem HeartMate 3 (HM3) unterstützt werden simulativ und experimentell nachgebildet. Die untersuchten hämodynamischen Zustände entsprechen Patienten die teilweise oder vollständig mit einem HM3 entlastet werden, wobei unterschiedliche Herzfrequenzen berücksichtigt sind – diese Zustände werden durch die entworfene Regelungsstrategie mit marginalen Kopplungseffekten und hoher Genauigkeit abgebildet, wobei der Füllstand stabil um den Sollwert schwankt. Diese Genauigkeit lässt sich in diesem Rahmen nicht mit herkömmlichen Eingrößenregelungen abbilden. Der neuartige atraumatische HTK erweitert damit den Stand der Technik und ermöglicht Hämokompatibilitätsuntersuchungen von Blutpumpen unter realistischen hämodynamischen Zuständen., Mock circulatory loops (MCL) have become a favorable platform for in-vitro testing of blood pumps. To date, conventional MCLs are not suitable to mimic realistic hemodynamic conditions without inducing hemolysis. Accordingly, in-vitro hemocompatibility assessment of blood pumps is limited to constant operating conditions that do not comply with the clinical application. The aim of this thesis was to develop an atraumatic MCL based on a hardware-in-the-loop concept (H-MCL) that allows hemocompatibility examinations under realistic pressure and flow conditions. The novel atraumatic H-MCL was designed for a low blood volume suitable for one blood bag (450±50 mL), with hemocompatible materials, atraumatic sensors and actuators, and a heating module in compliance with the standards of the American Society for Testing and Materials. These design choices required an advanced control structure, to control the pressures and the blood level within the system, based on a cardiovascular model that is calculating the hemodynamic response (new set pressures) to the current pump support (measured flow rate): To ensure physiologic reference tracking and to account for inherent coupling effects a decoupling pressure control was derived by feedback linearization and dynamic extension. Moreover, the level control was addressed by an optimization task, which provides a feasible control trajectory to overcome periodic loss of controllability and to ensure atraumatic actuator effort. As blood pump, the HeartMate 3 (HM3) was deployed to evaluate the H-MCL’s accuracy at characteristic hemodynamic conditions within partial and full support conditions, which were assessed for different dynamics in simulative and experimental studies. With the novel control approach all hemodynamic scenarios were replicated with marginal coupling effects while the mean fluid level consistently met the target value. Of note, this quality could not be achieved with a SISO control approach. The presented novel atraumatic design extends state-of-the-art H-MCLs and enables hemocompatibility assessment of blood pumps within realistic hemodynamic conditions.

The treatment of patients with advanced acute heart failure is still challenging. Intra-aortic balloon pump (IABP) has widely been used in the management of patients with cardiogenic shock. However, according to international guidelines, its routinary use in patients with cardiogenic shock is not recommended. This recommendation is derived from the results of the IABP-SHOCK II trial, which demonstrated that IABP does not reduce all-cause mortality in patients with acute myocardial infarction and cardiogenic shock. The present position paper, released by the Italian Association of Hospital Cardiologists, reviews the available data derived from clinical studies. It also provides practical recommendations for the optimal use of IABP in the treatment of cardiogenic shock and advanced acute heart failure.

In atrial and ventricular tachyarrhythmias, reduced time for ventricular filling and loss of atrial contribution lead to a significant reduction in cardiac output, resulting in cardiogenic shock. This may also occur during catheter ablation in 11% of overall procedures and is associated with increased mortality. Managing cardiogenic shock and (supra) ventricular arrhythmias is particularly challenging. Inotropic support may exacerbate tachyarrhythmias or accelerate heart rate; antiarrhythmic drugs often come with negative inotropic effects, and electrical reconversions may risk worsening circulatory failure or even cardiac arrest. The drop in native cardiac output during an arrhythmic storm can be partly covered by the insertion of percutaneous mechanical circulatory support (MCS) devices guaranteeing end-organ perfusion. This provides physicians a time window of stability to investigate the underlying cause of arrhythmia and allow proper therapeutic interventions (e.g., percutaneous coronary intervention and catheter ablation). Temporary MCS can be used in the case of overt hemodynamic decompensation or as a "preemptive strategy" to avoid circulatory instability during interventional cardiology procedures in high-risk patients. Despite the increasing use of MCS in cardiogenic shock and during catheter ablation procedures, the recommendation level is still low, considering the lack of large observational studies and randomized clinical trials. Therefore, the evidence on the timing and the kinds of MCS devices has also scarcely been investigated. In the current review, we discuss the available evidence in the literature and gaps in knowledge on the use of MCS devices in the setting of ventricular arrhythmias and arrhythmic storms, including a specific focus on pathophysiology and related therapies. ispartof: FRONTIERS IN CARDIOVASCULAR MEDICINE vol:9 ispartof: location:Switzerland status: published

Background: Risk factors for driveline infection (DLI) in patients with left ventricular assist devices are multifactorial. The aim of this study was to analyze the correlation between mechanical driveline features and DLI occurrence.Methods: A meta-analysis was conducted that included studies reporting DLI rates at 6 months after implantation of any of three contemporary devices (HVAD with Pellethane or Carbothane driveline, HeartMate II, and HeartMate 3). Further, outer driveline diameter measurements and ex-vivo experimental three-point bending and torsion tests were performed to compare the stiffness of the four different driveline types.Results: 21 studies with 5,393 patients were included in the meta-analysis. The mean weighted DLI rates ranged from 7.2% (HeartMate II) to 11.9% (HeartMate 3). The HeartMate II driveline had a significantly lower maximal bending force (Loadmax) (4.52 ± 0.19 N) compared to the Carbothane HVAD (8.50 ± 0.08 N), the HeartMate 3 (11.08 ± 0.3 N), and the Pellethane HVAD driveline (15.55 ± 0.14 N) (p < 0.001). The maximal torque (Torquemax) of the HeartMate II [41.44 (12.61) mNm] and the Carbothane HVAD driveline [46.06 (3.78) mNm] were significantly lower than Torquemax of the Pellethane HVAD [46.06 (3.78) mNm] and the HeartMate 3 [95.63 (26.60) mNm] driveline (p < 0.001). The driveline of the HeartMate 3 had the largest outer diameter [6.60 (0.58) mm]. A relationship between the mean weighted DLI rate and mechanical driveline features (Torquemax) was found, as the the HeartMate II driveline had the lowest Torquemax and lowest DLI rate, whereas the HeartMate 3 driveline had the highest Torquemax and highest DLI rate.Conclusions: Device-specific mechanical driveline features are an additional modifiable risk factor for DLI and may influence clinical outcomes of LVAD patients.

The patient in this report had a catastrophic case of transcatheter aortic valve replacement–related valve thrombosis manifesting within 1 month of valve implantation that was complicated by acute heart failure and cardiogenic shock. Anticoagulation and thrombolytic agents were not successful, and the patient was treated with TandemHeart (Cardiac Assist, Pittsburgh, Pennsylvania)–supported balloon aortic valvuloplasty and cerebral embolic protection. (Level of Difficulty: Advanced.), Graphical abstract, The patient in this report had a catastrophic case of transcatheter aortic valve replacement–related valve thrombosis manifesting within 1 month of…

Background: The literature on outcomes of patients requiring durable mechanical circulatory support (MCS) after extra-corporeal life support (ECLS) is limited. The aim of this study was to investigate the impact of preoperative ECLS cannulation on postoperative outcome after durable MCS implantation. Methods: The durable MCS after ECLS registry is a multicenter retrospective study that gathered data on consecutive patients who underwent durable MCS implantation after ECLS between January 2010 and August 2018 in eleven high volume European centers. Patients who underwent the implantation of total artificial heart, pulsatile pumps, or first-generation pumps after ECLS were excluded from the analysis. The remaining patients were divided into two groups; central ECLS group (cECLS) and peripheral ECLS group (pECLS). A 1:1 propensity score analysis was performed to identify two matched groups. The outcome of these two groups was compared. Results: A total of 531 durable MCS after ECLS were implanted during this period. The ECLS cannulation site was peripheral in 87% (n=462) and central in 13% (n=69) of the patients. After excluding pulsatile pumps and total artificial heart patients, a total of 494 patients remained (pECLS =434 patients, cECLS =60 patients). A 1:1 propensity score analysis resulted in 2 matched groups (each 55 patients) with median age of 54 years (48–60 years) in cECLS group and 54 years (43–60 years) in pECLS group. HeartWare HVAD (Medtronic, Minneapolis, MN) was implanted in the majority of the patients (cECLS =71% vs. pECLS =76%, P=0.67). All postoperative morbidities were comparable between the groups. The thirty-day, one year and long-term survival was comparable between the groups (P=0.73). Conclusions: The cannulation strategy of ECLS appears to have no impact on the post-operative outcome after durable MCS implantation.

Extracorporeal membrane oxygenation (ECMO) is life-saving for potentially reversible heart failure and respiratory injuries not responsive to conventional therapies. Technological innovations have produced over the years significant improvements in ECMO devices (pump, cannula design and oxygenator) and have allowed a better risk/benefit profile. Alongside with recognized advantages in the treatment of very sick patients, ECMO remains an invasive procedure for mechanical circulatory support (MCS) and it is associated with complications that strongly influence the prognosis. Current review was designed to provide a comprehensive outline on ECMO complications, analyzing risk factors and strategies of management, focusing on adult population undergoing veno-arterial ECMO (VA-ECMO) therapy.

Extracorporeal membrane oxygenation (ECMO) is life-saving for potentially reversible heart failure and respiratory injuries not responsive to conventional therapies. Technological innovations have produced over the years significant improvements in ECMO devices (pump, cannula design and oxygenator) and have allowed a better risk/benefit profile. Alongside with recognized advantages in the treatment of very sick patients, ECMO remains an invasive procedure for mechanical circulatory support (MCS) and it is associated with complications that strongly influence the prognosis. Current review was designed to provide a comprehensive outline on ECMO complications, analyzing risk factors and strategies of management, focusing on adult population undergoing veno-arterial ECMO (VA-ECMO) therapy.

Cardiogenic shock (CS), a state of inadequate tissue perfusion due to cardiac dysfunction, remains the leading cause of death following acute myocardial infarction (AMI). While the prognosis of CS post-AMI has improved in recent decades due to advances in treatment modalities, the mortality rates remain unacceptably high (~40–50% according to recent registries and clinical trials). Current treatment strategies for this condition include early revascularisation to restore blood flow to the ischaemic myocardium, the use of fluids and vasopressor or inotropic agents to reinstate haemodynamic parameters, and initiation of intra-aortic balloon counterpulsation (IABP) systems and active assist devices to maintain circulation. However, there is little evidence that these treatments actually improve survival rates. Even the most recent randomised trial conducted in this field (the IMPRESS trial comparing intra-aortic balloon counterpulsation to the Impella CP mechanical assist device) again failed to demonstrate any improvement in patient outcomes. The lack of evidence may reflect the relatively few randomised trials conducted in this area, likely due to difficulties in conducting such trials in an emergency setting. Moreover, most recent trials have focussed on patients in the late stages of CS, when they have become refractory to medical treatment and require mechanical circulatory support. This article reviews the available literature concerning the treatment of CS post-AMI in light of these limitations, and provides some evidence-based recommendations for best practice, including an updated treatment protocol.

Left ventricular assist devices (LVADs) have revolutionized therapy for patients with Stage D heart failure (HF) with reduced systolic function providing not only improved survival benefits but also meaningful changes in quality of life and functional capacity. With technological advances and improved durability of devices, length of survival has significantly improved. With continued organ donor shortage, LVADs are frequently serving as a substitute for cardiac transplant as destination therapy, particularly among the elderly. Internists not only face the important challenge of identifying the patients in need referral for these advanced therapies, they are also faced with the challenges of taking care of these patients. This review will help the internists to better understand the present status, indications and advances in LVADs and also understand the complications and adverse effects associated with these devices.

ObjectiveThe survival benefit of using mechanical circulatory support (MCS) in patients with acute myocardial infarction (AMI) is still controversial. It is necessary to explore the impact on clinical outcomes of MCS in patients with AMI undergoing stenting.DesignSystematic review and meta-analysis.Data sourcesEmbase, Cochrane Library, Medline, PubMed, Web of Science, ClinicalTrials.gov and Clinicaltrialsregister.eu databases were searched from database inception to February 2021.Eligibility criteriaRandomised clinical trials (RCTs) on MCS use in patients with AMI undergoing stent implantation were included.Data extraction and synthesisData were extracted and summarised independently by two reviewers. Risk ratios (RRs) and 95% CIs were calculated for clinical outcomes according to random-effects model.ResultsTwelve studies of 1497 patients with AMI were included, nine studies including 1382 patients compared MCS with non-MCS, and three studies including 115 patients compared percutaneous ventricular assist devices (pVADs) versus intra-aortic balloon pump (IABP). Compared with non-MCS, MCS was not associated with short-term (within 30 days) (RR=0.90; 95% CI 0.57 to 1.41; I2=46.8%) and long-term (at least 6 months) (RR=0.82; 95% CI 0.57 to 1.17; I2=37.6%) mortality reductions. In the subset of patients without cardiogenic shock (CS) compared with non-MCS, the patients with IABP treatment significantly had decreased long-term mortality (RR=0.49; 95% CI 0.27 to 0.90; I2=0), but without the short-term mortality reductions (RR=0.51; 95% CI 0.22 to 1.19; I2=17.9%). While in the patients with CS, the patients with MCS did not benefit from the short-term (RR=1.09; 95% CI 0.67 to 1.79; I2=46.6%) or long-term (RR=1.00; 95% CI 0.75 to 1.33; I2=22.1%) survival. Moreover, the application of pVADs increased risk of bleeding (RR=1.86; 95% CI 1.15 to 3.00; I2=15.3%) compared with IABP treatment (RR=1.86; 95% CI 1.15 to 3.00; I2=15.3%).ConclusionsIn all patients with AMI undergoing stent implantation, the MCS use does not reduce all-cause mortality. Patients without CS can benefit from MCS regarding long-term survival, while patients with CS seem not.