Increasing Utilization of Extended Criteria Donor Hearts for Transplantation: The OCS Heart EXPAND Trial.

BACKGROUND: Extended criteria donor (ECD) hearts available with donation after brain death (DBD) are underutilized for transplantation due to limitations of cold storage. OBJECTIVES: This study evaluated use of an extracorporeal perfusion system on donor heart utilization and post-transplant outcomes in ECD DBD hearts. METHODS: In this prospective, single-arm, multicenter study, adult heart transplant recipients received ECD hearts using an extracorporeal perfusion system if hearts met study criteria. The primary outcome was a composite of 30-day survival and absence of severe primary graft dysfunction (PGD). Secondary outcomes were donor heart utilization rate, 30-day survival, and incidence of severe PGD. The safety outcome was the mean number of heart graft-related serious adverse events within 30 days. Additional outcomes included survival through 2 years benchmarked to concurrent nonrandomized control subjects. RESULTS: A total of 173 ECD DBD hearts were perfused; 150 (87%) were successfully transplanted; 23 (13%) did not meet study transplantation criteria. At 30 days, 92% of patients had survived and had no severe PGD. The 30-day survival was 97%, and the incidence of severe PGD was 6.7%. The mean number of heart graft-related serious adverse events within 30 days was 0.17 (95% CI: 0.11-0.23). Patient survival was 93%, 89%, and 86% at 6, 12, and 24 months, respectively, and was comparable with concurrent nonrandomized control subjects. CONCLUSIONS: Use of an extracorporeal perfusion system resulted in successfully transplanting 87% of donor hearts with excellent patient survival to 2 years post-transplant and low rates of severe PGD. The ability to safely use ECD DBD hearts could substantially increase the number of heart transplants and expand access to patients in need. (International EXPAND Heart Pivotal Trial [EXPANDHeart]; NCT02323321; Heart EXPAND Continued Access Protocol; NCT03835754).

Two-Year Follow Up of the LATERAL Clinical Trial: A Focus on Adverse Events.

BACKGROUND: The LATERAL trial validated the safety and efficacy of the thoracotomy approach for implantation of the HeartWare HVAD System, leading to Food and Drug Administration approval. We sought to analyze 24-month adverse event (AE) rates, including a temporal analysis of the risk profile, associated with the thoracotomy approach for the HVAD system. METHODS: AEs from the LATERAL trial were evaluated over 2 years postimplant. Data was obtained from the Interagency Registry for Mechanically Assisted Circulatory Support database for 144 enrolled United States and Canadian patients. Temporal AE profiles were expressed as events per patient year. RESULTS: During 162.5 patient years of support, there were 25 driveline infections (0.15 events per patient year), 50 gastrointestinal bleeds (0.31 events per patient year), and 21 strokes (0.13 events per patient year). Longitudinal AE analysis at follow-up intervals of <30 and 30 to 180 days, and 6 to 12 and 12 to 24 months revealed the highest AE rate at <30 days, with a decrease in total AEs within the first 6 months. After 6 months, most AE rates either stabilized or decreased through 2 years, including a 95% overall freedom from disabling stroke. CONCLUSIONS: Two-year follow-up of the LATERAL trial revealed a favorable morbidity profile in patients supported with the HVAD system, as AE rates were more likely to occur in the first 30 days postimplant, and overall AE rates were significantly reduced after 6 months. Importantly, 2-year freedom from disabling stroke was 95%. These data further support the improving AE profile of patients on long-term HVAD support. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02268942.

Expert Consensus Paper: Lateral Thoracotomy for Centrifugal Ventricular Assist Device Implant.

BACKGROUND: The increasing prevalence of heart failure has led to the expanded use of left ventricle assist devices (VADs) for end-stage heart failure patients worldwide. Technological improvements witnessed the development of miniaturized VADs and their implantation through less traumatic non-full sternotomy approaches using a lateral thoracotomy (LT). Although adoption of the LT approach is steadily growing, a lack of consensus remains regarding patient selection, details of the surgical technique, and perioperative management. Furthermore, the current literature does not offer prospective randomized studies or evidence-based guidelines for LT-VAD implantation. METHODS: A worldwide group of LT-VAD experts was convened to discuss these key topics openly. After a PubMed search and review with all authors, a consensus was reached and an expert consensus paper on LT-VAD implantation was developed. RESULTS: This document aims to guide clinicians in the selection of patients suitable for LT approaches and preoperative optimization. Details of operative techniques are described, with an overview of hemisternotomy and bilateral thoracotomy approaches. A review of the best surgical practices for placement of the pump, inflow cannula, and outflow graft provides advice on the best surgical strategies to avoid device malpositioning while optimizing VAD function. Experts' opinions on cardiopulmonary bypass, postoperative management, and approaches for pump exchange and explant are presented. This review also emphasizes the critical need for multidisciplinary teams and specific training. CONCLUSIONS: This expert consensus review provides a compact guide to LT for VAD implantation, from patient selection through intraoperative tips and postoperative management.

Cost-Effectiveness of Thoracotomy Approach for the Implantation of a Centrifugal Left Ventricular Assist Device.

This study reports the first analysis regarding cost-effectiveness of left ventricular assist device (LVAD) implantation via thoracotomy. Cost-effectiveness of LVADs implanted via the traditional surgical approach of sternotomy has been improved through the years because of technological advances, along with understanding the importance of patient selection and postimplant management have on positively affecting outcomes. Given the positive clinical outcomes of the thoracotomy approach, we seek to study the cost-effectiveness of a centrifugal LVAD via this less invasive approach. We developed a Markov model. Survival and quality of life inputs (QALY) for the LVAD arm were based on data from the LATERAL clinical trial. For the Medical Management arm, survival was derived from the Seattle Heart Failure Model. The heart transplant probability was derived from INTERMACS. Survival after heart transplantation used International Society for Heart and Lung Transplantation data. Cost inputs were calculated based on Medicare data and past literature. The incremental cost-effectiveness ratio was found to be $64,632 per quality adjusted life year and $57,891 per life year in the bridge to transplant indication. These results demonstrate further improvement in the overall cost-effectiveness of LVAD therapy and confirm implantation of LVADs via a less invasive approach as being cost-effective.

Cost of Thoracotomy Approach: An Analysis of the LATERAL Trial.

BACKGROUND: Less invasive techniques for left ventricular assist device implantation have been increasingly prevalent over past years and have been associated with improved clinical outcomes. The procedural economic impact of these techniques remains unknown. We sought to study and report economic outcomes associated with the thoracotomy implantation approach. METHODS: The LATERAL clinical trial evaluated the safety and efficacy of the thoracotomy approach for implantation of the HeartWare centrifugal-flow ventricular assist device system (HVAD). We collected UB-04 forms in parallel to the trial, allowing analysis of index hospitalization costs. All charges were converted to costs using hospital-specific cost-to-charge ratios and were subsequently compared with Medicare cost data for the same period (2015-2016). Because thoracotomy implants were off-label for all left ventricular assist devices during that period, the Medicare cohort was assumed to consist predominately of traditional sternotomy patients. RESULTS: Thoracotomy patients demonstrated decreased costs compared with sternotomy patients during the index hospitalization. Mean total index hospitalization costs for thoracotomy were $204,107 per patient, corresponding to 21.6% reduction (P < .001) and $56,385 savings per procedure compared with sternotomy. Across almost all cost categories, thoracotomy implants were less costly. CONCLUSIONS: In LATERAL, a clinical trial evaluating the safety and efficacy of the thoracotomy approach for HVAD, costs were lower than those reported in Medicare patient claims occurring over the same period. Because Medicare data can be presumed to consist of predominately sternotomy procedures, thoracotomy appears less expensive than traditional sternotomy.

Long-Term Survival of Patients With Advanced Heart Failure Receiving an Left Ventricular Assist Device Intended as a Bridge to Transplantation: The Registry to Evaluate the HeartWare Left Ventricular Assist System.

BACKGROUND: The paucity of available hearts for transplantation means that more patients remain on durable left ventricular support for longer periods of time. The Registry to Evaluate the HeartWare Left Ventricular Assist System was an investigator-initiated multicenter, prospective, single-arm database established to collect post-Conformité Européene mark clinical information on patients receiving the HeartWare ventricular assist device system as a bridge to transplantation. This registry represents the longest multicenter follow-up of primary left ventricular assist device outcomes. METHODS: Data were collected on 254 commercial implants performed between February 2009 and March 2012 from 9 centers in Europe (7) and Australia (2). Patients were followed to device explant, heart transplantation, or death. The outcomes of patients through July/August 2018 were analyzed. Summary statistics were used to describe patient demographics, adverse events, length of support, and outcomes for this extended-term cohort. RESULTS: A total of 122 patients were on support for >2 years, and 34 patients were on support for >5 years. Twenty nine patients are still alive on support (support ranging from 1213 to 3396 days), and 23 of those are on their original HeartWare ventricular assist device system. Kaplan-Meier survival through 7 years was 51%. Through 6 years, freedom from any stroke was 82%, while freedom from severely disabling stroke was 89%. CONCLUSIONS: Low rates of heart transplant now require longer periods of left ventricular assist device support in patients. This analysis demonstrates that long-term support using a HeartWare ventricular assist device system offers survival of 51% through 7 years.

Evaluation of a lateral thoracotomy implant approach for a centrifugal-flow left ventricular assist device: The LATERAL clinical trial.

BACKGROUND: The HeartWare centrifugal-flow ventricular assist device system (HVAD) is a viable option for treatment of advanced heart failure. There is a growing trend toward the use of less invasive techniques in cardiac surgery, and the thoracotomy technique for HVAD implantation may provide benefits not available with conventional approaches. METHODS: The LATERAL trial is a multicenter, prospective, non-randomized, single-arm trial that utilized data from 144 patients enrolled in the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) database at 26 centers in the United States and Canada. The primary composite end-point was success at 180 days defined as alive on the originally implanted device and free from disabling stroke (modified Rankin Scale score >3), transplanted or explanted for recovery. The key secondary end-point was mean length of initial hospital stay. RESULTS: The primary end-point was successfully achieved in 88.1% of patients and was significantly greater than the pre-defined performance goal of 77.5% set from historical sternotomy data (p = 0.0012). The key secondary end-point-mean length of initial hospital stay -was 18 days and was significantly shorter than the pre-defined performance goal of 26.1 days obtained from historical sternotomy data (p < 0.0001). The adverse event profile further demonstrated the safety of the thoracotomy approach. The overall patient survival was good, and bleeding requiring reoperation was significantly less frequent than that observed in previous studies using the sternotomy approach. CONCLUSIONS: This prospective clinical trial provides validation that implantation of the HVAD system via the thoracotomy approach used in the LATERAL study represents a safe and effective alternative to median sternotomy in selected patients intended for a bridge-to-transplant indication.

von Willebrand factor disruption and continuous-flow circulatory devices.

Bleeding events remain a significant and frequent complication of continuous-flow left ventricular assist devices (VADs). von Willebrand factor (VWF) is critical to hemostasis by acting as a bridging molecule at sites of vascular injury for normal platelet adhesion as well as promoting platelet aggregation under conditions of high shear. Clinical and experimental data support a role for acquired von Willebrand disease in VAD bleeding episodes caused by shear-induced qualitative defects in VWF. Pathologic shear induces VWF unfolding and proteolysis of large multimers into smaller less hemostatic multimers via ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13). This review outlines the pathobiology of VWF disruption in the context of VADs as well as current diagnostic and management strategies of the associated acquired von Willebrand disease.

Lung Transplantation in Germany Since the Introduction of the Lung Allocation Score.

BACKGROUND: The allocation of donor lungs for transplantation in Germany was changed on 10 December 2011 to a system based on the Lung Allocation Score (LAS). The aim of the present study is to determine whether this change has prolonged the survival of patients on the transplant waiting list and of those who have undergone lung transplantation (LTx). METHODS: We retrospectively compared data from the three-year periods before and after the change to an LAS-based allocation system (2009-2011 vs. 2012-2014). RESULTS: The number of patients on the active waiting list declined from 606 on 12/31/2011 to 432 on 12/31/2014, a 29% decrease. The number of patients who died while on the waiting list fell from 306 in 2009-2011 to 226 in 2012-2014 (-26%, p = 0.04). Waiting-list mortality declined across all disease groups. Meanwhile, the number of lung transplantation procedures per year increased by 21% over the period of observation, from 865 to 1045. During the period in which the LAS was used, the proportion of transplant recipients with restrictive lung disease (46% vs. 31%; p<0.001) surpassed the proportion of those with a diagnosis of obstructive lung disease (33% vs. 40%; p = 0.003). The percentage of transplantations in patients treated with mechanical ventilation or extracorporeal respiratory support before transplantation rose from 9% to 13%. The one-year survival rate after lung transplantation was 76% in 2009-2011 and 81% in 2012-2014. CONCLUSION: The introduction of the LAS in Germany was associated with a decrease in the number of patients on the waiting list, and also in the number of deaths among patients on the waiting list. The distribution of primary diagnoses among transplant recipients shifted away from obstructive and toward restrictive lung diseases. In the future, additional parameters of patients on the waiting list should be considered to enable further improvement of the allocation model.

Evaluation of the HeartWare ventricular assist device Lavare cycle in a particle image velocimetry model and in clinical practice.

OBJECTIVES: Ventricular blood stasis is a concern for continuous flow mechanical support devices and might contribute to the formation of thromboembolic events. The HeartWare® Ventricular Assist System (HVAD®) is equipped with the Lavare™ cycle that is a periodic speed modulation feature designed to alter flow patterns within the left ventricle and reduce areas of potential blood stasis. Here, we report in vitro and clinical findings on the effects of the Lavare cycle. METHODS: The effect of pump speed changes on the intraventricular flow field was examined with an in vitro particle image velocimetry model. The clinical impact of the Lavare cycle was evaluated through a retrospective review of the ReVOLVE study which includes 248 patients implanted with the HVAD following Conformité Européenne Mark in nine centres in Europe and Australia. Baseline characteristics, adverse event profiles and Kaplan-Meier survival estimates were stratified by patients using/not using the Lavare cycle. RESULTS: Particle image velocimetry showed increased ventricular washout with an active Lavare cycle as measured by the fluid velocities and angular dispersion parameters. With the Lavare cycle on, there was also a 22% decrease in the stagnation index compared with when the Lavare cycle was off. In the ReVOLVE registry, patients with the Lavare cycle turned on (n = 215) were supported for 497 patient-years, whereas patients who did not use the speed modulation (n = 33) were supported for 39.3 patient-years. The Lavare cycle did not significantly affect patient survival as both groups had approximately an 80% survival after 1 year. Patients using the Lavare cycle had significantly fewer rates of stroke [0.06 vs 0.20 events per patient-year (EPPY), P = 0.0008], sepsis (0.03 vs 0.15 EPPY, P = 0.0003) and right heart failure (0.03 vs 0.18 EPPY, P < 0.0001) with no difference in the transplant or recovery rates among the two cohorts. CONCLUSIONS: The Lavare cycle effectively generates ventricular washout and the adverse event profiles of ReVOLVE patients with the Lavare cycle on were better than those with the Lavare cycle off. Larger studies are warranted to verify the positive effect of the Lavare cycle and to optimize speed modulation settings, so additional clinically relevant improvements can be realized.

Long-term support of patients receiving a left ventricular assist device for advanced heart failure: a follow-up analysis of the Registry to Evaluate the HeartWare Left Ventricular Assist System.

OBJECTIVES: The Registry to Evaluate the HeartWare Left Ventricular Assist System (ReVOLVE) is an investigator-initiated multicentre, prospective, single-arm database established to collect post-Conformité Européenne Mark clinical information on patients receiving the HeartWare® Ventricular Assist System (HVAD®). The number of patients requiring longer periods of mechanical circulatory support is ever increasing and so further investigation into long-term outcomes in bridge-to-transplant populations is necessary. METHODS: Data were collected on 254 commercial implants performed between February 2009 and March 2012 from nine centres in Europe (7 centres) and Australia (2 centres). Patients were followed to device explant, heart transplant or death, and the outcomes of patients who remained on support longer than 2 years were analysed. Summary statistics were used to describe patient demographics, adverse events, length of support and outcomes for this long-term cohort. RESULTS: A total of 124 patients (49% of the original ReVOLVE population) were on support for more than 2 years (range: 731-2108 days), 76 of whom are still alive on support. Overall survival through 5 years was 59%. CONCLUSIONS: Owing to the low rate of heart transplants, a significant number of patients receiving a left ventricular assist device as a bridge to transplant remain on support for prolonged periods, often exceeding 2, 3 and even 4 years. Real-world use of the HVAD system continues to show excellent outcomes for patients on the device, including those on support beyond 2 years.

Repair of an acute Type A aortic dissection with LVAD patient after failed mitral and tricuspid operation.

An acute type A dissection in a patient with a left ventricular assist device was treated by replacement of the ascending aorta and the proximal arch using a prosthesis with a side branch which was connected to the left ventricular assist device outflow branch, greatly simplifying the procedure.

Preoperative Determinants of Quality of Life and Functional Capacity Response to Left Ventricular Assist Device Therapy.

BACKGROUND: Left ventricular assist devices (LVADs) improve survival, quality of life (QOL), and functional capacity (FC) among patients with end-stage heart failure. Few data are available regarding characteristics associated with QOL and FC response. METHODS AND RESULTS: Patients enrolled in the Heartmate II clinical trials that were alive with ongoing LVAD support at 6 months were included. QOL response criteria included scoring above the lowest quartile on either the Minnesota Living With Heart Failure Questionnaire or the Kansas City Cardiomyopathy Questionnaire. FC responder criteria included improvement in 6-minute walk distance (6MWD) >70 meters from baseline, a 6MWD >220 meters at 6 months, or New York Heart Association functional class I or II. Independent variables associated with QOL nonresponse included history of diabetes (odds ratio [OR] 1.82, 95% confidence interval [CI] 1.20-2.78), lower mean pulmonary arterial pressure (OR 0.97, 95% CI 0.95-0.99), or a Heartmate II right ventricular risk score >2 (OR 1.77, 95% CI 1.00-3.12). Variables associated with FC nonresponse included history of COPD (OR 1.92, 95% CI 1.22-3.03) or diabetes (OR 1.52, 95% CI 1.01-2.27). Compared with responders, QOL and FC nonresponders had reduced long-term survival. CONCLUSIONS: Preoperative comorbidities, including diabetes, COPD, and right heart failure, may limit the QOL and FC response to LVAD therapy and should be considered during the shared decision-making process.

Retrograde in situ versus antegrade pulmonary preservation in clinical lung transplantation: a single-centre experience.

OBJECTIVE: Experimental and clinical studies have indicated a beneficial effect of retrograde lung preservation on post-transplant results. Accordingly, we conducted a non-randomized trial. METHODS: A total of 209 consecutive recipients transplanted with low-potassium dextrane (LPD)-preserved lungs were eligible for analysis. Antegrade lung preservation (AP) was performed in 173 patients and retrograde in situ perfusion (RP) in 36 patients using low-potassium dextrane solution in all cases. The prostacycline was added to preservation solution. RESULTS: The main donor, graft and recipient characteristics did not differ significantly between groups. There was a beneficial trend toward improved oxygenation indices in the RP cohort within the initial 48 post-transplant hours. The incidence of severe primary graft dysfunction was comparable up to 48 h post-transplant and was significantly increased in the RP cohort 72 h post-transplant (2.2% AP vs 14.8% RP, P = 0.016). Fatal bronchial dehiscences occurred more often in RP recipients (5.6% RP vs 0.6% AP, P = 0.067). The occurrence of bronchial stenoses revealed a slightly improved trend in the RP group (24.9% AP vs 13.9% RP, P = 0.218). Survival (P = 0.927) and bronchiolitis obliterans syndrome-free survival (P = 0.337) were comparable between groups. CONCLUSION: In our clinical survey, this analysis does not confirm the beneficial results of retrograde lung preservation alone, as was previously observed in experimental studies.

Influence of aortic valve opening in patients with aortic insufficiency after left ventricular assist device implantation.

OBJECTIVES: Aortic valve insufficiency (AI) following left ventricular assist device (LVAD) implantation can potentially limit the success of mechanical circulatory support. We examined the prevalence of significant AI in the new generation of LVADs and analysed the role of aortic valve opening in the development of AI in these patients. METHODS: Currently, 102 patients that received a continuous flow LVAD (cf-LVAD) between July 2009 and December 2013 are being treated in our outpatient clinic with an HeartWare ventricular assist device (HVDA) (n = 77) or HeartMate II (HMII, n = 25) and were included and analysed in a retrospective study. The mean age of the 12 female and 90 male patients was 54 ± 12 years. Ischaemic cardiomyopathy was diagnosed in 40% of patients. Echocardiographic measurements were reviewed before and after implantation. AI was considered significant if it was more than mild. RESULTS: Mean LVAD support duration was 572 ± 437 days. Significant AI was found in 32 patients (31.4%). De novo AI occurred in mean after 183 ± 246 days of support. One patient presented severe AI and received an aortic valve replacement. A permanently closed aortic valve correlates with a greater prevalence of AI when compared with intermittent or complete opening of aortic valve (P = 0.004). Aetiology of the cardiomyopathy and the type of device had no influence on the development of AI. Smaller left ventricle end-diastolic diameter and lower body surface area were significantly associated with the development of aortic insufficiency in our cohort. CONCLUSION: Aortic insufficiency has a high prevalence following assist device continuous flow support. Echocardiographic parameters are an integral part of ambulatory care of these patients and can guide the optimal setting for LVAD. An aortic valve that does not open should be avoided in order to prevent AI. Patients with HMII or HVAD did not show any differences terms of the prevalence of aortic insufficiency prevalence.