Ezin Deniz

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.

Left Ventricular Assist Device Implantation With Outflow Graft Tunneling Through the Transverse Sinus

Impairment of coronary artery flow, in either acute or chronic conditions, is a severe complication of transcatheter aortic valve (TAV) implantation, which can arise due to improper TAV positioning. However, little work has been done to quantify the effects of the TAV positioning on the coronary flow. In this study, a realistic in vitro model of coronary artery flow was developed and used to investigate the impact of TAV deployed orientations on coronary flow. The coronary hemodynamics was first replicated mathematically using a lumped parameter model with time-varying myocardial resistance. Based on the analytical model, two stepper motor controlled stopcock valves were integrated in a left heart simulator to represent the variable myocardial resistance in the experimental setup. The coronary flow and pressure waveforms obtained from the in vitro system were consistent with published data. With a TAV deployed in different orientations, the measured results demonstrated that TAV orientation does not have a significant impact on the coronary flow. The developed in vitro model can be further utilized to simulate coronary flow under various pathological conditions.

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.

Which Approach? Traditional Versus MICS

Consistently enhanced technology, research, and gain of clinical experience within the first decade of this century have established ventricular assist devices (VADs) as important option for the treatment of congestive heart failure. The introduction of miniaturized devices allowing less invasive surgical implantation has been revolutionizing the field during the past years, excluding the need of full sternotomy. There is a growing consensus of opinion that less invasive techniques are becoming routine in LVAD surgery. Thus, recent data suggest that intrahospital survival rates following less invasive VAD implantation are surpassing 90%. The gathering of miniaturized pumps and innovative surgical techniques will push this field forward to even better outcomes and reduced complication rates. The purpose of this book chapter is to review novel surgical techniques for implantation, exchange, and explantation of left ventricular assist devices.

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.

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.

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.

Analysis of LVAD log files for the early detection of pump thrombosis

Nowadays, one standard therapy for advanced heart failure is the implantation of left ventricular assist devices (LVAD). The LVAD is a mechanical pump, which supports the heart to pump blood to the rest of the body. However, there are serious complications including pump thrombosis. Pump thrombosis is a formation of blood clot inside the LVAD pump, which can result in pump stop and worst case leads to death. To increase the probability of success in thrombosis treatment, an early diagnosis of pump thrombosis is important. An often mentioned indication for pump thrombosis is an increase in pump current. For this reason, this paper analyzes the log files of LVAD patients. Four algorithms were developed and applied to the measured pump current with the aim to detect an increase in pump current earlier as it is actually done by the physician. The first algorithm incorporated different absolute thresholds. In addition, the second algorithm considered the circadian fluctuation to estimate suitable thresholds. The third and fourth algorithms applied a relative threshold based on the standard deviation of the pump current. The third algorithm applied a standard deviation, which is calculated for each patient and each hours of the day individually. The fourth algorithm used for each patient an individual average standard deviation. This paper shows the results of 5 pump thromboses curves analyzed with the different algorithms each. Using the fourth algorithm, a pump current increase was detected approximately 4 days earlier compared to the “High Watt” alarm caused by the LVAD controller.

Successful HeartMate 3 implantation in isolated right heart failure—first in man experience of right heart configuration

In this article, we present the case of a 72-year-old male patient suffering from a severe form of singular isolated end-stage right heart failure based on arrhythmogenic right ventricular cardiomyopathy (ARVC), who was admitted to our clinic for acute cardiac decompensation.

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.