Algorithms to guide ambulance clinicians in the management of emergencies in patients with implanted rotary left ventricular assist devices.

Advances in left ventricular assist device (LVAD) therapy have resulted in increasing numbers of adult LVAD recipients in the community. However, device failure, stroke, bleeding, LVAD thrombosis and systemic infection can be life-threatening emergencies. Currently, four LVAD systems are implanted in six UK transplant centres, each of which provides device-specific information to local emergency services. This has resulted in inconsistent availability and content of information with the risks of delayed or inappropriate decision-making. In order to improve patient safety, a consortium of UK healthcare professionals with expertise in LVADs developed universally applicable prehospital emergency algorithms. Guidance was framed as closely as possible on the standard ABCDE approach to the assessment of critically ill patients.

Myocardial Recovery Strategy with Decommissioning for the HeartWare Left Ventricular Assist Device.

To manage myocardial recovery in patients with the HeartWare left ventricular assist device (HVAD), we describe a minimally invasive approach (decommissioning) that involves disconnecting the driveline and occluding the outflow tract through a small left thoracotomy incision, leaving the device in situ, in conjunction with optimal medical therapies and comprehensive assessment of left ventricular recovery. Nine patients (all male, 37 ± 12 years, all nonischemic dilated cardiomyopathy) had an HVAD implanted for 766 ± 343 days. When left ventricular function improved to mild impairment by echocardiography, patients underwent assessment at reduced flow (2578 ± 148 to 1822 ± 67 rpm) with documentation of compensated right heart hemodynamics and ejection fraction 52 ± 8%. Eight of nine patients underwent decommissioning, and 1 patient had a hybrid procedure of percutaneous occlusion of outflow graft and surgical division of driveline. Two patients died postoperatively at 413 days (sepsis) and 810 days (heart failure). In conclusion, in selected patients with nonischemic dilated cardiomyopathy, a prolonged period of HVAD support in conjunction with heart failure medications can lead to recovery of left ventricular function. Surgical decommissioning is then an option to remove these patients from support. These patients are, however, not cured and remain at risk for future deterioration in ventricular function and infections.

International coordinator survey results on the outpatient management of patients with the HeartWare® ventricular assist system.

PURPOSE: While the HeartWare® Ventricular Assist System (HVAS) is a successful therapy for end-stage heart failure, outpatient management methods can vary significantly and require further investigation. METHODS: A survey to assess the long-term HVAS patient management and monitoring strategies was completed by 36 international heart centers that currently have over 1,450 patients on VAD support either at home or in the hospital. Multiple choice questions examined VAD program characteristics, anticoagulation management, driveline exit-site dressing and showering recommendations, blood pressure and pump parameter monitoring, and patient discharge protocols. RESULTS: Outpatient international normalized ratio (INR) was most frequently measured every 3-4 days (28.6%), and the most frequent schedule for changing driveline exit site dressings was 3 times per week (30.6%). Only 25.7% of centers required their patients to measure blood pressure at home. A subgroup analysis was performed to assess the influence of center experience and larger centers generally had more frequent monitoring compared to smaller centers. CONCLUSIONS: This survey showed specific differences in outpatient management strategies that were previously unreported. However, further studies with correlations to patient outcomes are necessary to determine optimal patient management recommendations.

Impact of aortic valve closure on adverse events and outcomes with the HeartWare ventricular assist device.

BACKGROUND: This study examined whether aortic valve opening (AVO) and other echocardiographic parameters influence outcomes in patients on left ventricular (LV) assist device (LVAD) support. Pump thrombosis (PT) and ischemic stroke (IS) are known complications of LVAD, but mechanisms that could influence them are not completely understood. METHODS: This was a retrospective analysis of 147 patients who received a HeartWare Ventricular Assist Device ( HeartWare International) as a bridge to transplant or to candidacy between July 2009 and August 2015, of whom 126 had at least 30 days of follow-up before the first event (30-days-out cohort). Outcomes included survival, PT, IS, and PT+IS (combined thrombotic event; CTE). RESULTS: Median time on support was 518 days. Of the 30-days-out cohort, 29% had a first PT and 19% a first IS. AVO was associated with longer survival on device (1,081 vs 723 days; p = 0.01) in the entire cohort. In the 30-days-out cohort, the aortic valve was more frequently closed in patients with lower ejection fractions on support (14% ± 6% vs 18% ± 9%; p = 0.009), more dilated pre-event echocardiogram (LV end-diastolic diameter, 66 ± 12 mm vs 62 ± 10 mm; p = 0.04), and pre-implant LV end-diastolic diameter (70 ± 10 mm vs 66 ± 9 mm; p = 0.06). CTE-free survival on the device was lower with a closed aortic valve (897 vs 1,314 days; p = 0.003) as was PT-free survival on the device (1,070 vs 1,457 days; p = 0.02). Cox regression analysis showed that AVO was an independent predictor of CTE (p = 0.03) CONCLUSIONS: Thrombotic events are relatively frequent in patients on long-term LVAD support. A closed aortic valve was associated with decreased overall survival, thrombosis-free survival, and poorer LV function on support. These are high-risk patients, so whether they require more intense anti-coagulation or prioritizing for transplantation requires further research.

Development of de novo aortic valve incompetence in patients with the continuous-flow HeartWare ventricular assist device.

BACKGROUND: In this study we investigated the development of aortic incompetence (AI) and change in aortic root and left ventricular dimensions after implantation of the continuous-flow HeartWare ventricular assist device (HVAD) in our adult patient cohort. METHODS: A retrospective analysis of serial echocardiograms was performed on patients implanted with an HVAD between July 2009 and July 2013. Data from echocardiograms performed before and at 1 and 2 years (±3 months) were analyzed. Patients with native aortic valves (AoVs) with no previous intervention and HVAD in situ for ≥6 months were included. RESULTS: A total of 73 HVADs in 71 patients with a mean duration of support of 624 ± 359 days were included in our study. One patient developed moderate AI at 1 year (1.9%). Mild or greater AI was more likely in those with a closed or intermittently opening AoV at 1 year (p = 0.005). Aortic annulus dimensions increased significantly at 1 and 2 years, regardless of extent of AI. At 2 years, in those with mild or worse AI, the sinuses of Valsalva were also larger (p = 0.002). Left ventricular end-diastolic dimension (LVEDD) was significantly reduced in those with no or trace AI at 1 and 2 years (p = 0.012 and p = 0.008, respectively), but remained unchanged in those with AI at both time-points. CONCLUSIONS: The development of more than mild AI is rare in HVAD patients at our center. When encountered, it is more common with a closed AoV. Dilation of the aortic annulus, and root dilation in those with mild or more AI, is seen with HVAD support over time.

Successful HeartWare Bridge to Recovery in a 3-Year Old: A Game Changer?

We report a 3-year-old boy weighing 13.5 kg who presented with intractable cardiac failure resulting from myocarditis and was treated by implantation of a HeartWare (HVAD) device. He was discharged home with the device. His cardiac function subsequently recovered, and the device was decommissioned. We believe this to be the youngest HVAD recipient and the only child to have recovered and had the device decommissioned.

An Extended Role of Continuous Flow Device in Pediatric Mechanical Circulatory Support.

BACKGROUND: Mechanical circulatory support in the pediatric population is currently limited to pulsatile ventricular assist devices (VAD). In recent years, the use of durable, newer generation, continuous flow devices have increased substantially among adults with end-stage heart failure. We examined the extended role of this device in the pediatric population (aged less than 18 years). METHODS: Between 2010 and 2015, 12 patients (median age 7.1 years; range, 3.7 to 17.0; one third of patients were aged 5 years or less) received a HeartWare ventricular assist device (HVAD; HeartWare, Framingham, MA), 11 for cardiomyopathy and 1 for posttransplant rejection. Right VAD support (n = 5; 42%) was provided by a short-term device (Levitronix, Zurich, Switzerland). RESULTS: Overall, 1 patient died (day 638), 8 patients (67%) underwent transplantation, 1 patient (8.3%) recovered, and 2 patients (17%) remain on HVAD. The mean length of support was 150 days (range, 16 to 638). Four patients (33.3%) were discharged home (all left VAD). In the left VAD group (n = 7), 3 patients subsequently received transplants (days 185, 201, and 234, respectively), 1 recovered (day 149), 1 died (day 638), 1 remained on HVAD (day 198), and 1 needed conversion to biventricular assist device (BIVAD [day 73]). In the BIVAD group (n = 5), right VAD was weaned in 3 (60%), all subsequently received transplants, and 2 remained on BIVAD support until transplant (days 16 and 17, respectively). One BIVAD patient required conversion to central cannulation for longer-term support. Four BIVAD patients (80%) were in Interagency Registry for Mechanically Assisted Circulatory Support level 1 before VAD compared with 2 (29%) in the left VAD group (p = not significant). The actuarial survival rate was 100% at 1 year with no neurologic events. CONCLUSIONS: The third-generation, continuous flow device can provide durable support in the pediatric population. The selection strategy for patients who benefit most from the device continues to evolve. It is anticipated that a smaller design in the future will benefit an even wider pediatric population with heart failure.

Rescue cardiac transplantation for early failure of the Fontan-type circulation in children.

OBJECTIVE: Early failure of the Fontan-type circulation is a potentially fatal complication. We review our experience with cardiac transplantation in children presenting with end-stage heart failure in this scenario. METHODS: We performed a retrospective review. Between 1985 and 2003, 6 children aged less than 16 years were referred for cardiac transplantation. The indication for cardiac transplantation was end-stage cardiac failure early after the completion of the Fontan-type operation. RESULTS: All 6 patients listed for transplantation underwent cardiac transplantation; the median interval to transplantation from the operation was 36 days (range, 6-180 days). Four patients had undergone the Fontan procedure, and 2 had one-and-a-half-ventricle repair. All 6 patients were ventilated and inotrope dependent, with varying degrees of multiorgan dysfunction. One patient was bridged to transplantation with extracorporeal membrane oxygenation. The median age at transplantation was 7.1 years (range, 3-12.5 years), and weight was 18.9 kg (range, 11-35 kg). One patient died on the operating table (graft failure and hemorrhage). In 5 survivors the median intensive care unit stay was 10 days (range, 8-61 days). On follow-up of 6 to 81 months, there have been no subsequent deaths, and the quality of life in survivors is good. CONCLUSION: Rescue cardiac transplantation in the setting of an early failure of the Fontan-type circulation and end-stage cardiac failure is an effective treatment option and can be performed with acceptable early mortality and encouraging short-term to medium-term results.

Care of the heart transplant patient.

Cardiac transplantation is recognised as an effective treatment option for severe heart failure in carefully selected recipients. This article emphasises the importance of a multidisciplinary team approach and focuses on the first 24-48 hours of postoperative care. It discusses organ rejection; pain control; infection; psychological implications and rehabilitation. Survival rates and a brief history of transplantation are also provided.

Four-year outcomes with third-generation centrifugal left ventricular assist devices in an era of restricted transplantation.

OBJECTIVES: Third-generation ventricular assist devices (VADs) are associated with improved outcomes, though in recent clinical trials bridge-to-transplant (BTT) rates are ∼30% at 6 months, so that transplantation can be used as a 'bail out' for serious complications. In the UK, there was a significant reduction in heart transplantation rates over the last decade, so that transplantation from VADs is much less frequent. The objective of this study was to determine outcomes and their predictors in this situation of low BTT rates, and as patients were exposed to long-term support, the incidence and outcomes of VAD thrombosis. METHODS: We analysed outcomes for 102 consecutive patients between 2009 and 2013 (mean age 47 ± 13; VentrAssist n = 6 and HeartWare n = 96). The median duration of support was 462 ± 426 days. RESULTS: Survival rates on the device were 75 and 66% at 1 and 2 years, respectively. Older age and more acute INTERMACS groups were significantly related to reduced survival within the first 90 days (P = 0.030 and 0.010, respectively). Poor preoperative right ventricular (RV) function had a negative effect on survival after 1 year (P = 0.009), though not earlier. VAD thrombosis (n = 24 HeartWare and n = 1 VentrAssist) occurred at 0.18 events per patient-year for HeartWare and 0.07 for VentrAssist devices at a median time of onset at 404 ± 281 days. There was no significant effect of VAD thrombosis on survival. Only 14 of 102 patients were transplanted at a median of 334 ± 347 days, and only 3 were transplanted within the first 6 months. CONCLUSIONS: Third-generation left ventricular assist device implants with a low rate of transplantation have similar survival to destination therapy, and are susceptible to long-term complications of VAD thrombosis and right heart failure.

Durable ventricular assist device support for failing systemic morphologic right ventricle: early results.

BACKGROUND: The systemic morphologic right ventricle (RV) in congenitally corrected transposition of the great arteries or after atrial switch for transposition of the great arteries is associated with late ventricular failure. Although the role of the left ventricular assist device (LVAD) in supporting the failing LV is established, the indications and outcomes of using LVAD in a systemic RV remain unclear. We assessed the role of a third-generation LVAD for systemic RV support. METHODS: Seven patients (mean age, 36 years) received the HeartWare (HeartWare International Inc, Framingham, MA) VAD for systemic RV failure (congenitally corrected transposition of the great arteries in 1 and after atrial switch in 6). Four patients (57%) had severe subpulmonic LV failure, and aggressive perioperative diuresis with or without hemofiltration was used to offload the subpulmonic LV. The indications of VAD were (1) bridge to transplant in 3 and (2) bridge to decision for a high transpulmonary gradient in 4. Transplantation outcome was compared with systemic RV failure without VAD bridge in 19 patients (years 1989 to 2013). RESULTS: Systemic RV support alone was achieved in all patients, with no early deaths (≤30 days). Overall, 6 (86%) returned home, 3 (44%) received a transplant, 2 (28%) died of noncardiac causes, and 2 (28%) continue on VAD support (median support, 232 days). Repeat catheterization (n = 4) showed an improved median transpulmonary gradient in 3 patients (median 18.5 mm Hg pre-VAD vs 8.0 mm Hg post-VAD). Two bridge-to-decision patients received transplants at 640 and 685 days. The stroke rate on VAD support was 43% (2 thromboembolic and 1 hemorrhagic; 3 with satisfactory recovery). De novo aortic regurgitation was 29% (n = 2; 1 valve replacement). All patients (n = 3) survived transplantation (vs 10.5% early mortality without VAD bridge; p = 1.00) and were well at follow-up (range, 53 to 700 days). CONCLUSIONS: The third-generation VAD provides durable support for systemic RV failure as a bridge to transplant and as a strategy to reduce pulmonary vascular resistance. Although concomitant subpulmonic LV failure is common, systemic RV support alone was achieved in all patients.

Hemodynamic, echocardiographic, and exercise-related effects of the HeartWare left ventricular assist device in advanced heart failure.

The aim of this study was to determine the effects of the HeartWare left ventricular assist device (HVAD) (HeartWare International, Inc, Framingham, MA) on hemodynamics, ventricular function, and exercise capacity. Between July 2009 and March 2011, 46 patients with advanced heart failure had implantation of the HVAD. Of these patients, 30 had subsequent assessments for transplantation and these patients formed the study cohort. Thirty patients had assessments at a mean of 201±86 days and 13 went on to have a second assessment at 351±86 days. There were marked improvements in hemodynamics and exercise capacity at both assessments, with significant decreases in right and left heart filling pressures; increases in cardiac index, New York Heart Association class, and peak exercise oxygen consumption; and reduction in pulmonary vascular resistance (all P<.05). Left ventricular end-diastolic and end-systolic dimensions were unchanged at the first assessment, although there was a significant reduction in end-diastolic diameter at the second assessment (P<.01). There were no significant changes in a visual grade of right ventricular function. After up to 1 year of support, the HVAD system results in significant benefits in overall heart failure status, with improved hemodynamics and exercise capacity. This occurs in the absence of marked changes in left ventricular size or right ventricular function.

An alternative approach to explantation and exchange of the HeartWare left ventricular assist device.

OBJECTIVES: Left ventricular assist device (LVAD) explantation and exchange is a relatively infrequent but potentially complex procedure. Patients requiring such procedures have multisystem suboptimal physiological reserve due to end-stage heart failure and are prone to complications. Less-invasive procedures are believed to facilitate postoperative recovery and early mobilization. We describe an alternative approach to explantation and exchange of the HeartWare LVAD through left thoracotomy. METHODS: Six patients (M = 4, F = 2, mean age = 49.16 years) underwent device explant/exchange or initial implant (explant = 2, exchange = 3, initial implant = 1) through left thoracotomy utilizing cardiopulmonary bypass and induced ventricular fibrillation (VF). The mean bypass time and mean VF arrest time were 82 and 3 min, respectively. A new outflow graft was anastomosed to the previous outflow graft in 3 cases of device exchange and to the descending aorta in 1 case of initial implant. RESULTS: One patient died in the intensive care unit due to unrelated causes (gram-negative sepsis) after device exchange. All others were discharged alive and currently remain on follow-up. The mean length of hospital stay was 40.66 days. CONCLUSIONS: On-pump approach through single thoracotomy incision is safe and equally suitable for device explant, exchange and initial implant. However, structural heart defects requiring surgical correction and the requirement of simultaneous right ventricular assist device are the limitations of this approach.

Outcomes following more than two decades of paediatric cardiac transplantation.

OBJECTIVE: There have been significant changes in the field of paediatric cardiac transplantation over the last two decades. We report experience of over 22 years from a single UK transplant centre. METHODS: A total of 189 orthotopic cardiac transplants were performed in 182 children aged <18 years between March 1987 and March 2009 in our institution. Patients were identified and outcomes reviewed using the cardiopulmonary transplant database and hospital medical records. RESULTS: 182 patients underwent cardiac transplantation, mean age 8.3 years (0.1-17.9 years), 91 (50%) male. Mean follow-up time was 9.0 years (0.3-22.3 years). 117 patients (64%) had a diagnosis of cardiomyopathy, 65 (36%) had congenital heart disease. There was no significant difference in age at transplant between the group with cardiomyopathy and the group with congenital heart disease. 32 patients (17.6%) were on mechanical support prior to transplant. Three (1.6%) patients have required long-term renal replacement therapy post transplant, and 16 (8.8%) developed post-transplant lymphoproliferative disease. Survival was 93% at 30 days, 89% at 1 year, 85% at 5 years, 70% at 10 years and 67% at 15 years with a decrease in mortality over time. Seven patients (3.8%) were re-transplanted. CONCLUSIONS: Outcomes following cardiac transplantation in childhood are improving with increased experience. There has been a reduction in 30-day mortality over time.