Hemodynamical Evaluation of a New Surgically Implanted Pulsatile Right Ventricular Assist Device Driven by a Conventional Intra-Aortic Balloon Pump Console.

Severe right heart failure, often overlooked and challenging to manage, has prompted a growing interest in innovative approaches to provide functional support. This study uses experimentation in large porcine models to introduce a novel prototype of a pulsatile mechanical circulatory support device and document its effects when deployed as a right ventricular assist device (RVAD). The pulsatile ventricular assist platform (pVAP), featuring a membrane pump driven by an intra-aortic balloon pump console, actively generates pulsatile flow to propel right ventricular blood into the pulmonary artery. This novel prototype demonstrates promising potential in addressing the challenges of right heart failure management. After preliminary in vitro assessments, the pVAP was tested on seven porcine models in a healthy state and after the induction of right ventricular failure. During the procedure, a set of standard (ie, standard-of-care) hemodynamic measurements was obtained. Additionally, invasive pressure-volume loop analysis was employed to examine left ventricular hemodynamics. Results indicated that activation of the pVAP during right ventricular failure significantly improved systemic hemodynamics and enhanced left ventricular function. This study sheds light on the potential of the pVAP in managing right heart failure.

Left ventricular assist device implantation in patients with left ventricular thrombus.

An intra-cavitary left ventricular (LV) thrombus is a relative contraindication to LV assist device (LVAD) implantation based on increased thromboembolic risks. Herein, we present our experience with LVAD patients with or without preoperative diagnosis of LV-thrombus. We retrospectively investigated 563 patients who received LVAD implantation between 2004 and 2018. Diagnosis of LV-thrombus was verified with computed tomography scan, magnetic resonance imaging, echocardiography, or intraoperative LV inspection. The primary endpoint was 30-day survival free of stroke and pump thrombosis. Overall, 72 patients (12.8%) had a diagnosis of LV-thrombus. They were younger (51 years; IQR:41-59), affected by severely reduced ejection fraction (15%; IQR:10-20), more often presenting with dilated cardiomyopathy (61.8%) and INTERMACS profile 1 (33.3%). Preoperative atrial fibrillation was frequent in patients without LV-thrombus (38.9%). Conventional sternotomy was the preferred approach in LV-thrombus patients (77.8%), based on more HMII implantations in these patients (41.7%). Survival free of strokes and pump thrombosis at 30 days was comparable (P = .5751) between patients with (83.3%) or without LV-thrombus (80.9%). LVAD implantation in patients with preoperative LV-thrombus is safe and feasible. When managed through correct diagnostic and intraoperative strategies including accurate inspection of the LV cavity, these patients show similar 30-day outcomes compared to patients without LV-thrombus.

Device profile of the heartware HVAD system as a bridge-to-transplantation in patients with advanced heart failure: overview of its safety and efficacy.

Introduction: Heart failure (HF) is one of the rising problems in the contemporary society with growing incidences of end-stage HF. While heart transplantation (HT) is the gold standard treatment for end-stage HF, its availability is limited by the lack of heart donors. As a consequence, left ventricular assist devices (LVADs) are becoming key therapies as bridge to transplant (BTT) strategy to improve survival and outcomes.Areas covered: A significant advancement for wider applications of LVADs as BTT was facilitated by the introduction of miniaturized pumps such as the HVAD (HeartWare®, Medtronic, MN, USA), allowing intrapericardial implants and less-invasive approaches. In this review article, we describe the technical features of the HVAD and its outcomes in terms of efficacy and safety when implanted as BTT strategy. Moreover, we discuss the postoperative results of HT in HVAD recipients and its application in the pediatric population.Expert opinion: It has been demonstrated that the HVAD positively influences the survival of end-stage HF patients awaiting HT, with an acceptable rate of adverse events. Due to its reduced size, it is particularly suitable for LVAD implantations through lateral thoracotomy and in patients with small thoracic dimensions.

An acoustic method for systematic ventricular assist device thrombus evaluation with a novel artificial thrombus model.

BACKGROUND: Pump thrombosis (PT) is still one of the major adverse events in patients supported with left ventricular assist devices. Nowadays, thrombus detection relies on clinical parameters like reoccurring heart failure symptoms, on changes in pump power consumption, and on laboratory parameters such as increased LDH and hemolysis. Once detected PT is most often persistent and refractory to medical therapy. We therefore designed a novel, non-invasive acoustic method for early pump thrombus detection in an in vitro artificial thrombus model. METHODS: The study was performed in vitro using a mock circulation loop, artificial blood (water-glycerin) and artificial thrombus material (silicon) allowing for repeatable and defined testing. Tested ventricular assist device (VAD) type was HVAD (Medtronic). Three different thrombus locations were evaluated: on the tilted pad of the rotor, in the primary flow path, and in the secondary flow path beneath the rotor. After evaluating baseline parameters (no thrombus, n=20 for each pump), the influence of thrombi of seven different masses (no thrombus, 0.5-5.0 mg) on pump power consumption and acoustic emission of four HVAD devices was investigated via a microphone system (Sennheiser) and subsequent frequency spectrum analysis (n=12). The acoustic analysis algorithm included the number of frequency peaks recorded. RESULTS: Measurements with thrombi on the tilted pad showed an increased number of frequency peaks with all thrombus sizes compared to baseline measurements without any thrombus (baseline: 32.7±7.4; 0.5 mg: 45.3±10.4 up to 5 mg: 80.4±5.5). Power consumption was relevantly elevated in 5mg thrombus measurement only (6.3±1.29 W compared to 4.9±0.14 W at baseline). Measurements with thrombi in the primary and secondary showed no relevant alteration in power consumption and frequency peak count. CONCLUSIONS: We present an acoustic method that detects pump thrombi located on the tilted pad of the HVAD rotor requiring ten times less mass compared to thrombi detected by power consumption alterations used in current detection algorithms. Assuming that pump thrombi are growing over several days, the presented method may detect PT much earlier thereby increasing efficacy of medical therapy and helping to avoid pump exchange.

MitraClip procedure prior to left ventricular assist device implantation.

BACKGROUND: Functional mitral valve regurgitation is a frequent consequence of left ventricular dysfunction in patients with severe heart failure and is associated with a poor prognosis. It is hypothesized that in this patient group the mitral valve repair, respectively replacement, improves hemodynamics and clinical symptoms. As operative interventions with the help of heart-lung-machine are high risk procedures in these cases, the transcatheter mitral repair with MitraClip® (Abbott Vascular, IL, USA) has recently become frequently used. Most of these cases experience a progress in left ventricular dysfunction, which finally leads to in an implantation of a left ventricular assist device. In this report, we describe a series of six cases in which patients with end stage heart failure and consecutive functional mitral valve regurgitation were supported with a left ventricular assist device after MitraClip implantation. We aimed to investigate, whether the MitraClip implantation leads to an improvement of the hemodynamic prior left ventricular assist device (LVAD)-implantation. METHODS: We retrospectively analyzed the data of 6 patients (5 males, 1 female) with severe heart failure, who underwent LVAD implantation after the MitraClip procedure. The mean age at MitraClip procedure was 64.6 years, mean age at time of LVAD implantation was 65.5 years. The parameters examined were cardiac index (CI), left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVEDD) and the pulmonary capillary wedge pressure (PCWP). RESULTS: All patients had functional mitral regurgitation (MR). Severity of MR was reduced successfully in all treated patients. All patients were discharged with MR I-II and NYHA functional class III or IV after MitraClip procedure. The mean CI was 2.93 before MitraClip procedure and 2.36 before LVAD-Implantation. Mean LVEDD was 71 mm before MitraClip, mean LVEDD was 70.6 mm before LVAD, and 63.2mm after LVAD implantation respectively. The mean PCWP was 21.5 mmHg before MitraClip and 19.8 mmHg before LVAD implantation respectively. The mean left ventricular ejection fraction (LVEF) was 19.2% before MitraClip, the mean LVEF was 17.6% before LVAD and 15% after LVAD implantation. Two of the LVAD implanted patients died due to post-operative complications. There were no complications after MitraClip procedure. CONCLUSIONS: Our presented patient cohort presented little hemodynamic improvement after the MitraClip procedure. There was no clinical benefit for the patients after MitraClip procedure, progressing left ventricular dysfunction could not be prevented and resulted in subsequent LVAD implantation.

Clinical overview of the HVAD: a centrifugal continuous-flow ventricular assist device with magnetic and hydrodynamic bearings including lateral implantation strategies.

Growing worldwide incidences of end-stage heart failure and declining rates of cardiac transplants have given rise to the need for alternative treatment options, based on mechanical circulatory support (MCS) devices such as left ventricular assist devices (LVADs). Technologically advanced LVADs such as the HVAD® (HeartWare®, Medtronic) facilitate safe and efficient treatment of heart failure patients with reduced post-operative complications, which is attributed to their considerably miniaturized size. This also facilitates the development and implementation of novel, minimally-invasive surgical techniques. The HVAD is a centrifugal pump, manufactured by HeartWare Inc., (Framingham, MA, USA) and subsequently by Medtronic Inc., (Minnesota, MN, USA), and has been approved for clinical application after receiving the CE Mark approval in 2008 and the FDA approval in 2012. Current research efforts are focused on further miniaturization alongside optimization of electronic and software controllers as well as implementation of the transcutaneous energy transfer (TET) technology. Salient features of the HVAD pump technology, clinical applications and future optimization strategies have been discussed in this article.

A new tool for an explantation strategy of HeartMate 3™ left ventricular assist device.

Although rare, recovery of cardiac function after mechanical support of the left ventricle is the most desirable therapeutic goal in the treatment of end-stage heart failure.Herein, we present a novel implantable device for explantation of the HeartMate 3™ left ventricular assist device (LVAD) in patients, following cardiac recovery, avoiding (re-) sternotomy.This article demonstrates the feasibility of applying this novel device, which fits into the sewing ring of the LVAD.This custom-made mechanical plug offers a promising alternative to standard device-explantation procedures.

Exercise Capacity and Functional Performance in Heart Failure Patients Supported by a Left Ventricular Assist Device at Discharge From Inpatient Rehabilitation.

Adequate physical and functional performance is an important prerequisite for renewed participation and integration in self-determined private and (where appropriate) professional lives following left ventricular assist device (LVAD) implantation. During cardiac rehabilitation (CR), individually adapted exercise programs aim to increase exercise capacity and functional performance. A retrospective analysis of cardiopulmonary exercise capacity and functional performance in LVAD patients at discharge from a cardiac rehabilitation program was conducted. The results from 68 LVAD patients (59 males, 9 females; 55.9 ± 11.7 years; 47 HVAD, 2 MVAD, 15 HeartMate II, 4 HeartMate 3, and 4 different implanting centers) were included in the analysis. Exercise capacity was assessed using a cardiopulmonary exercise test on a bicycle ergometer (ramp protocol; 10 W/min). The 6-min walk test was used to determine functional performance. At discharge from CR (53 ± 17 days after implantation), the mean peak work load achieved was 62.2 ± 19.3 W (38% of predicted values) or 0.79 ± 0.25 W/kg body weight. The mean cardiopulmonary exercise capacity (relative peak oxygen uptake) was 10.6 ± 5.3 mL/kg/min (37% of predicted values). The 6-min walk distance improved significantly during CR (325 ± 106 to 405 ± 77 m; P < 0.01). No adverse events were documented during CR. The results show that, even following LVAD implantation, cardiopulmonary exercise capacity remains considerably restricted. In contrast, functional performance, measured by the 6-min walk distance, reaches an acceptable level. Light everyday tasks seem to be realistically surmountable for patients, making discharge from inpatient rehabilitation possible. Long-term monitoring is required in order to evaluate the situation and how it develops further.

Five-year results of patients supported by HeartMate II: outcomes and adverse events.

OBJECTIVES: Improved outcomes over the past decade have increased confidence of physicians and patients in extended duration of left ventricular assist device (LVAD) support. This single-centre cohort study reports 5-year outcomes with the HeartMate II (HMII) LVAD. METHODS: We describe a cohort of 89 patients who received a HMII LVAD between February 2004 and December 2010. The causes of death and adverse events were assessed by examination of medical records. A total of 202.74 patient-years were analysed. RESULTS: After 5 years, of the 89 patients, 15 patients remained on device therapy, 39 patients died, 28 patients underwent heart transplantation and 7 patients underwent explantation of the HMII for recovery. One year after the HMII implantation, there was a survival of 71% in the study cohort. In the following years, the survival rate was 65% in the 2nd year, 63% in the 3rd year, 56% in the 4th year and 54% after 5 years of LVAD support. Ten LVAD exchanges were performed in 8 (11%) patients. Currently (March 2017), 12 patients still remain on their original device. The longest ongoing patient on the HMII has been supported for over 11 years (4097 days). The most common adverse events were bleeding (68%; 1.5837 events per patient-year) and LVAD infection [49%; 1.0666 events per patient-year]. Seven cases of pump thrombosis were described (8%; 0.1131 events per patient-year). CONCLUSIONS: This is the first single-cohort study to describe a 5-year survival of HMII patients on extended duration of support. A 5-year survival of 54% was observed in this single-centre cohort.

Adaptive Pump Speed Algorithms to Improve Exercise Capacity in Patients Supported with a Left-Ventricular Assist Device.

For the treatment of terminal heart failure, the therapy with left-ventricular assist devices has already been established. In the systems used today, pump speed does not adjust during physical activity so that cardiac output and exercise capacity remain markedly limited. It is the aim of this study to develop an automatic pump speed control based on filling pressure values in order to improve exercise capacity and quality of life in these patients. Different approaches are planned, to be tested in an in vitro patient simulator. The algorithms aim to match the pump speed with the increased venous return. In addition, preservation of aortic valve function should be taken into account.

Telemonitoring and Medical Care of Heart Failure Patients Supported by Left Ventricular Assist Devices - The Medolution Project.

Long-term survival after left ventricular assist device (LVAD) implantation in heart failure patients is mainly determined by a sophisticated after-care. Ambulatory visits only take place every 12 weeks. In case of life-threatening complications (pump thrombosis, driveline infection) this might lead to delayed diagnosis and delayed intervention. It is the intention of the international project Medolution (Medical care evolution) to develop new approaches in order to create best structures for telemonitoring of LVAD patients. In the very early period of the project a questionnaire was sent to 180 LVAD patients to evaluate the need and acceptance of telemonitoring. Thereafter, a graphical user interface (GUI) mockup was developed as one of the first steps to improve the continuous contact between the LVAD patient and the physician. As a final goal the Medolution project aims to bundle all relevant informations from different data sources into one platform in order to provide the physician a comprehensive overview of a patient's situation. In the systems background a big data analysis should run permanently and should try to detect abnormalities and correlations as well. At crucial events, a notification system should inform the physician and should provide the causing data via a decision support system. With this new system we are expecting early detection and prevention of common and partially life-threatening complications, less readmissions to the hospital, an increase in quality of life for the patients and less costs for the health care system as well.

First experiences with HeartMate 3 follow-up and adverse events.

BACKGROUND: The novel HeartMate 3 (HM3) left ventricular assist device (LVAD) received its CE mark in October 2015. It is a new compact LVAD featuring fully magnetically levitated pump, artificial pulse, large pump gaps, and a modular driveline. Here, we present outcomes and adverse events of a single-center cohort 6 months after HM3 implantation. METHODS: We retrospectively studied a patient cohort of 27 patients who were supported with the HM3 at a single institution. We excluded patients with biventricular assist devices and other types of assist devices as well as LVAD exchange and re-operative procedures. RESULTS: Twenty-seven patients were enrolled into the study. Within 1 year after HM3 implantation, 1 patient received a heart transplant and 3 patients died. Thirty-day survival was 88.9% and 6 months 85.2%. No pump thrombosis and no strokes were observed within 6 months. Right heart failure was diagnosed in 1 patient after HM3 implantation (3.7%). No technical complications of the pump were documented. No pump exchanges were necessary. CONCLUSIONS: The novel LVAD HM3 has already shown good CE mark trial results. Within this first report after the CE mark trial, the 6-month survival after HM3 implantation was 85.2%. The HM3 showed excellent midterm results with 0% stroke and 0% pump thrombosis rates 6 months after implantation.

First series of left ventricular assist device exchanges to HeartMate 3.

OBJECTIVES: Left ventricular assist device (LVAD) exchange is becoming a standard surgical procedure. The exchange procedure is an opportunity to upgrade patients to a new generation pump that offers advanced reduction of adverse events or longer battery hours. METHODS: We performed an analysis of 6 consecutive patients who underwent LVAD exchange to HeartMate 3 either from a HeartWare or HeartMate (HM) II device. Minimally invasive operations were performed through a lateral thoracotomy. Follow-up time was 6 months after LVAD exchange. RESULTS: We present 4 patients with the HM II and 2 patients with the HeartWare ventricular assist device (HVAD) who underwent LVAD exchange to HM III. The average age was 57.5 years. At the time of the LVAD exchange, all patients were classified as Interagency Registry for Mechanically Assisted Circulatory Support level 3. In 5 cases, LVAD infection led to LVAD exchange (83%, 5/6). The remaining patient underwent LVAD exchange due to pump thrombosis (16%, 1/6). The 6-month survival rate after LVAD exchange was 100% (6/6). None of the patients was postoperatively supported by extracorporeal membrane oxygenation. No patient experienced postoperative relevant bleeding. One patient suffered minor cerebral bleeding (16.6%, 1/6). At the 6-month follow-up examination, 1 patient reported a single syncope and several low-flow alarms (1/6). The remaining 5 patients showed no adverse events or technical malfunctions of the VAD (5/6). CONCLUSIONS: LVAD exchanges from HM II as well from HVAD to HM 3 are proven to be technically feasible. Due to the advantages and technical improvements of the new-generation pumps, this procedure is an excellent opportunity to give patients access to a superior generation of assist device.

In Vitro Evaluation of Inflow Cannula Fixation Techniques in Left Ventricular Assist Device Surgery.

The therapy of terminal heart failure with left ventricular assist devices has become a standard in cardiac surgery. Yet the surgical implantation technique is not standardized and differs from center to center. Complications associated with left ventricular assist device (LVAD) inflow cannula placement are thrombosis, suction events, and flow disturbances. Within this in vitro study we aimed to investigate if the fixation technique of the sewing ring has an impact on the position of the inflow cannula. For this in vitro study the HeartMate III LVAD (Thoratec Corporation, Pleasanton, CA, USA) was used. In five sessions, two approaches were considered for coring of the ventricle for LVAD inflow cannula insertion: "sew-then-core" and "core-then-sew." In the "sew-then-core" technique, the sewing cuff is first affixed to the heart, usually with 8-16 interrupted pledgeted mattress sutures. Subsequently, a cylindrical knife is used to resect a cylindrical core of myocardium to permit cannula insertion. In the "core-then-sew" technique, the sequence is reversed such that the knife is used before the suture ring is affixed. When the "sew-then-core" technique is used, the mattress sutures may be placed with full-thickness bites that penetrate the endocardium (i.e., transmural stitching) or partial-thickness bites that do not penetrate the endocardium (i.e., epicardial stitching). When the "core-then-sew" technique is used, the suture is passed fully into the ventricular lumen and fed back through the cored hole, at which point the needle may be reinserted into the freshly cored myocardium such that it exits the epicardium (i.e., transmural stitching with back stitch) or not (i.e., transmural stitching without back stitch). These four different sewing ring fixation suturing techniques were tested by experienced surgeons to affix the sewing ring: transmural stitching, epicardial stitching, transmural stitching with back stitch, and transmural stitching without back stitch. The sewing ring was sewed onto a silicone dummy designed to simulate the left ventricle with standard 2-0 Ethibond sutures (Ethicon, Somerville, NY, USA). Afterward, the dummies were measured and documented via photography. In addition, porcine hearts were used to simulate the suturing techniques in a physiological setting. The setting of the inflow cannula is substantially influenced by the fixation method of the sewing ring. Epicardial stitching showed the best results with stable cannula fixation, minimal gap around the cannula and no contact between the sutures and sewing ring with blood. The method of transmural stitching without back stitch showed the worst results by creating the biggest epithelial gap between inflow cannula and tissue as well as proving the biggest surface for blood contact between sewing ring and sutures. In general, both "sew-then-core" techniques resulted in a greater degree of apposition between the cuff and epicardial tissue. Within the study we revealed that the surgical fixation of the sewing ring has a significant impact on the inflow cannula stability, position, and tissue apposition in LVAD implantation surgery. Epicardial stitching of the sewing ring provides the best results in order to prevent suction events as well as thrombosis formation.

Physical and psychological long-term outcome after traumatic brain injury in children and adult patients.

BACKGROUND: Several studies have indicated that younger age is associated with worse recovery after pediatric traumatic brain injury (TBI) compared to elder children. In order to verify this association between long-term outcome after moderate to severe TBI and patient's age, direct comparison between different pediatric age groups as well as an adult population was performed. METHODS: This investigation represents a retrospective cohort study at a level I trauma center including patients with moderate to severe, isolated TBI with a minimum follow-up of 10 years. According to their age at time of injury, patients were divided in pre-school (0-7 years), school (8-17 years) and adult (18-65 years) patients. Physical examination and standardized questionnaire on physical and psychological aspects (Glasgow Outcome Scale, Barthel Index, Impact of Event Scale, Hospital Anxiety and Depression Scale, short form 12) were performed. RESULTS: 135 traumatized patients were included. Physical and psychological long-term outcome was associated with injury severity but not with patients' age at time of injury. Outcome recovery measured by Glasgow Outcome Scale was demonstrated with best results for pre-school aged children (p = 0.009). According to the Hospital Anxiety and Depression Scale an increased incidence of anxiety (p = 0.010) and depression (p = 0.026) was evaluated in older patients. CONCLUSION: Long-term outcome perceptions after moderate to severe TBI presented in this study question current views of deteriorated recovery for the immature brain. The sustained TBI impact seemed not to reduce the child's ability to overcome the suffered impairment measured by questionnaire based psychological, physical and health related outcome scores. These results distinguish the relevance of rehabilitation and family support in the long term.

Subjective impact of traumatic brain injury on long-term outcome at a minimum of 10 years after trauma- first results of a survey on 368 patients from a single academic trauma center in Germany.

BACKGROUND: Traumatic Brain Injury (TBI) may lead to significant impairments in personal, social and professional life. However, knowledge of the influence on long-term outcome after TBI is sparse. We therefore aimed to investigate the subjective effects of TBI on long-term outcome at a minimum of 10 years after trauma in one of the largest study populations in Germany. METHODS: The current investigation represents a retrospective cohort study at a level I trauma center including physical examination or standardized questionnaires of patients with mild, moderate or severe isolated TBI with a minimum follow-up of 10 years. We investigated the subjective physical, psychological and social outcome evaluating the Glasgow Outcome Scale, short-form 12, and social as well as vocational living circumstances. RESULTS: 368 patients aged 0 to 88 years were included. Patients with severe TBI were younger compared to patients with moderate or mild TBI (p < 0.05). Patients with severe TBI lived more often as single after the trauma impact. A significantly worse outcome was associated with higher severity of TBI resulting in an increased incidence of mental disability. A professional decline was analyzed in case of severe TBI resulting in significant loss of salary. CONCLUSIONS: The severity of TBI significantly influenced the subjective social and living conditions. Subjective mental and physical outcome as well as professional life depended on the severity of TBI 10 years after the injury.