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).

Domino heart transplant following heart-lung transplantation: a systematic review and meta-analysis.

BACKGROUND: The domino-donor operation occurs when a "conditioned" heart from the heart-lung transplant (HLT) recipient is transplanted into a separate heart transplant (HT) recipient. The purpose of this systematic review was to investigate the indications and outcomes associated with the domino procedure. METHODS: An electronic search was performed to identify all prospective and retrospective studies on the domino procedure in the English literature. Eight studies reported 183 HLT recipients and 263 HT recipients who were included in the final analysis. RESULTS: HLT indications included cystic fibrosis in 58% (95% CI: 27-84%) of recipients, primary pulmonary hypertension (PPH) in 17% (95% CI: 12-24%), bronchiectasis in 5% (95% CI: 3-10%), emphysema in 5% (95% CI: 0-45%), and Eisenmenger's syndrome in 4% (95% CI: 2-8%). HT indications included ischemic heart disease in 40% (95% CI: 33-47%), non-ischemic disease in 39% (95% CI: 25-56%), and re-transplantation in 10% (95% CI: 1-59%). The pooled mean pulmonary vascular resistance (PVR) in HT recipients was 3.05 Woods units (95% CI: 0.14-5.95). The overall mortality in the HLT group was 28% (95% CI: 18-41%) at an average follow-up of 15.68 months (95% CI: 0.82-30.54), and 35% (95% CI: 17-58%) in the HT group at an average follow-up of 37.26 months (95% CI: 6.68-67.84). Freedom from rejection in HT was 94% (95% CI: 75-99%) at 1 month, 77% (95% CI: 30-96%) at 6 months, and 41% (95% CI: 33-50%) at 1 year. CONCLUSIONS: The domino procedure appears to be a viable option in properly selected patients that can be performed safely with acceptable outcomes.

The Effect of Acute Pulmonary Hypertension on Tricuspid Annular Height, Strain, and Curvature in Sheep.

The tricuspid annulus shows significant alterations in patients with functional tricuspid regurgitation-tricuspid valve dysfunction that is secondary to other diseases such as pulmonary hypertension. Early changes in annular shape and dynamics may provide an understanding of disease mechanisms and could predict disease progression. To gain a mechanistic insight into these early changes we perform a spatially-resolved analysis of the effect of acute pulmonary hypertension on the tricuspid annulus in sheep. To this end, we suture sonomicrometry crystals to the annulus of nine sheep and record their locations in the beating heart, before and after inducing acute pulmonary hypertension. Using least-squares cubic splines, we derive mathematical representations of the annulus to describe pulmonary hypertension-induced annular shape changes via strain, relative curvature, and relative annular height between the control group and the acute pulmonary hypertension group. Moreover, we determine hypertension-induced alterations to annular dynamics as within-group strains, relative curvature, and relative height throughout the cardiac cycle for each group. We confirm that the annulus in acute pulmonary hypertension dilates significantly, becomes more circular, and flattens. Our regional analysis reveals that annular dilation, circularization, and flattening are driven by highly localized changes in annular strains, curvature, and height. Additionally, we find that acute pulmonary hypertension alters annular dynamics, albeit minimally. This regionally-resolved analysis of acute hypertension-induced changes of annular shape and dynamics provides insight into early disease mechanisms, and may inspire future generations of annuloplasty devices and techniques that address spatial annular heterogeneities.

Engineering Analysis of Tricuspid Annular Dynamics in the Beating Ovine Heart.

Functional tricuspid regurgitation is a significant source of morbidity and mortality in the US. Furthermore, treatment of functional tricuspid regurgitation is suboptimal with significant recurrence rates, which may, at least in part, be due to our limited knowledge of the relationship between valvular shape and function. Here we study the dynamics of the healthy in vivo ovine tricuspid annulus to improve our understanding of normal annular deformations throughout the cardiac cycle. To this end, we determine both clinical as well as engineering metrics of in vivo annular dynamics based on sonomicrometry crystals surgically attached to the annulus. We confirm that the tricuspid annulus undergoes large dynamic changes in area, perimeter, height, and eccentricity throughout the cardiac cycle. This deformation may be described as asymmetric in-plane motion of the annulus with minor out-of-plane motion. In addition, we employ strain and curvature to provide mechanistic insight into the origin of this deformation. Specifically, we find that strain and curvature vary considerable across the annulus with highly localized minima and maxima resulting in aforementioned configurational changes throughout the cardiac cycle. It is our hope that these data provide valuable information for clinicians and engineers alike and ultimately help us improve treatment of functional tricuspid regurgitation.

Airway complications after lung transplantation: Contemporary survival and outcomes.

BACKGROUND: Airway complications are rare and cause increased morbidity and mortality after lung transplantation (LT). We sought to examine risk factors associated with this complication and its impact on survival. METHODS: We retrospectively evaluated United Network for Organ Sharing data from 2000 to 2012. A backward stepwise logistic regression was performed on recipient-, donor-, and transplant-related variables to select independent risk factors associated with airway complications and mortality. Survival was evaluated using the Kaplan-Meier method. RESULTS: We evaluated 16,156 consecutive adult LT recipients, among whom 233 (1.4%) developed airway complications. Predictors of increased risk of airway complications included male gender (odds ratio [OR] 1.61, p = 0.001), advancing recipient age (OR 1.02, p < 0.001) and pre-transplantation admission to the intensive care unit (ICU) (OR 2.13, p < 0.001). The 30-day (89.6% vs 96.2%, p = 0.001), 90-day (69.9% vs 93.1%, p < 0.001), 1-year (54.6% vs 84.4%, p < 0.001), 3-year (38.7% vs 67.4%, p < 0.001) and 5-year (33.2% vs 54.2%, p < 0.001) survival rates were each significantly reduced in recipients with airway complications. Factors associated with an increased risk of 1-year mortality included recipient age (hazard ratio [HR] 1.01, p < 0.001), use of extracorporeal mechanical support (HR 1.5, p = 0.01), diagnosis of cystic fibrosis (HR 1.22, p = 0.01), glomerular filtration rate (GFR) 60 to 90 ml/min/1.73 m2 (HR 1.61, p < 0.001), GFR <60 ml/min/1.73 m2 (HR 1.13, p = 0.01), non-ICU hospitalization (HR 1.32, p < 0.001), pre-transplantation ICU hospitalization (HR 2.54, p < 0.001), donor with positive serology for cytomegalovirus (HR 1.16, p < 0.001) and donor with a smoking history (HR 1.19, p < 0.001). Double LT (HR 0.83, p < 0.001) was associated with a decreased risk of death. Chronic obstructive pulmonary disease/emphysema was protective compared with idiopathic pulmonary fibrosis (HR 0.85, p = 0.008). CONCLUSION: Airway complications are associated with a significant mortality burden.

The effect of acute mechanical left ventricular unloading on ovine tricuspid annular size and geometry.

OBJECTIVES: Left ventricular assist device (LVAD) implantation may alter right ventricular shape and function and lead to tricuspid regurgitation. This in turn has been reported to be a determinant of right ventricular (RV) failure after LVAD implantation, but the effect of mechanical left ventricular (LV) unloading on the tricuspid annulus is unknown. The aim of the study was to provide insight into the effect of LVAD support on tricuspid annular geometry and dynamics that may help to optimize LV unloading with the least deleterious effect on the right-sided geometry. METHODS: In seven open-chest anaesthetized sheep, nine sonomicrometry crystals were implanted on the right ventricle. Additional nine crystals were implanted around the tricuspid annulus, with one crystal at each commissure defining three separate annular regions: anterior, posterior and septal. Left ventricular unloading was achieved by connecting a cannula in the left atrium and the aorta to a continuous-flow pump. The pump was used for 15 min at a full flow of 3.8 ± 0.3 l/min. Epicardial echocardiography was used to assess the degree of tricuspid insufficiency. Haemodynamic, echocardiographic and sonomicrometry data were collected before and during full unloading. Tricuspid annular area, and the regional and total perimeter were calculated from crystal coordinates, while 3D annular geometry was expressed as the orthogonal distance of each annular crystal to the least squares plane of all annular crystals. RESULTS: There was no significant tricuspid regurgitation observed either before or during LV unloading. Right ventricular free wall to septum diameter increased significantly at end-diastole during unloading from 23.6 ± 5.8 to 26.3 ± 6.5 mm (P = 0.009), but the right ventricular volume, tricuspid annular area and total perimeter did not change from baseline. However, the septal part of the annulus significantly decreased its maximal length (38.6 ± 8.1 to 37.9 ± 8.2 mm, P = 0.03). Annular contraction was not altered. The tricuspid annulus had a complex 3D saddle-shaped geometry that was unaffected during experimental conditions. CONCLUSIONS: In healthy sheep hearts, left ventricular unloading increased septal-free wall RV diameter and reduced the length of the septal annulus, without altering the motion or geometry of the tricuspid annulus. Acute left ventricular unloading alone in healthy sheep was not sufficient to significantly perturb tricuspid annular dynamics and result in tricuspid insufficiency.

Procedural volume and survival after lung transplantation in the United States: the need to look beyond volume in the establishment of quality metrics.

BACKGROUND: We sought to evaluate the effect of center volume on patient survival. METHODS: We performed a retrospective analysis on nationwide data from the Scientific Registry of Transplant Recipients provided by United Network for Organ Sharing pertaining to lung transplantation (LT) recipients transplanted between 2005 and 2013. Centers were categorized into 4 groups based on their annual volume as follows: less than 20, 20 to 29, 30 to 39, and greater than or equal to 40 LTs. Baseline characteristics were compared and Kaplan-Meier analysis was used to estimate survival. RESULTS: A total of 13,506 adult recipients underwent LT during the study period. Of these, 2,491 (18.4%) patients were transplanted in centers with volume less than 20, 2,562 (19.0%) in centers with volume 20 to 29, 2,998 (22.2%) in centers with volume 30 to 39, and 5,455(40.4%) in centers with volume greater than or equal to 40. Survival was poorest in the lowest volume centers (1-year 81.4% vs 85.5% and 5-year 49.7% vs 56.5%, respectively). CONCLUSIONS: Post-LT survival in low volume centers is significantly lower than in high volume centers but the explanatory power of volume as a predictor of survival is low.

The effect of pulmonary hypertension on ovine tricuspid annular dynamics.

OBJECTIVES: Pulmonary hypertension (PHT) is associated with tricuspid annular dilatation, but the effect of acute increase of pulmonary pressure on three-dimensional (3D) tricuspid annular dynamics and shape is unknown. Better understanding of tricuspid annular dynamics may lead to improved and more durable surgical reparative techniques. METHODS: In nine open-chest anaesthetized sheep nine sonomicrometry crystals were implanted on the right ventricle while on cardiopulmonary bypass. Additional nine crystals were implanted around the tricuspid annulus (TA) with one crystal at each commissure defining three separate annular regions: anterior, posterior and septal. Two additional equidistant crystals were implanted between each commissure, creating three segments for every region. Pressure transducers were placed in the left ventricular (LV), right ventricular (RV) and right atrium. PHT was induced by acute pulmonary artery constriction with a pneumatic occluder. Sonomicrometry and echocardiographic data were collected before and after induction of PHT. TA area, regional and total perimeter, and 3D annular geometry were calculated from 3D crystal coordinates. Regional annular contraction was defined as the percentage difference between maximal and minimal region length during the cardiac cycle. RESULTS: PHT increased RV pressure from 31 ± 9 mmHg to 46 ± 13 mmHg (P = 0.001) and decreased left ventricular (LV) pressure from 111 ± 24 mmHg to 78 ± 36 mmHg (P = 0.018). There was no significant tricuspid regurgitation observed with PHT. During PHT, the TA area increased by 12 ± 13% from 641 ± 139 mm(2) to 721 ± 177 mm(2) (P = 0.037). The total perimeter increased from 103 ± 11 mm to 109 ± 13 mm (P = 0.02). All annular regions dilated significantly with PHT with 8 ± 10, 5 ± 5 and 5 ± 5% increase in anterior, posterior and septal annular length, respectively (P < 0.05). PHT reduced regional annular contraction in the anterior region only (17 ± 7 vs 14 ± 8%; P = 0.02). The TA had a complex 3D saddle geometry and the shape of the annulus was altered during PHT only in the antero-posterior region. CONCLUSIONS: The changes in tricuspid annular conformation, contractility and its 3D geometry observed during acute ovine PHT may help in the design of new pathology-specific tricuspid annular rings.

A global perspective of lung transplantation: Part 1 - Recipient selection and choice of procedure.

Lung transplantation has grown considerably in recent years and its availability has spread to an expanding number of countries worldwide. Importantly, survival has also steadily improved, making this an increasingly viable procedure for patients with end-stage lung disease and limited life expectancy. In this first of a series of articles, recipient selection and type of transplant operation are reviewed. Pulmonary fibrotic disorders are now the most indication in the U.S., followed by chronic obstructive pulmonary disease and cystic fibrosis. Transplant centers have liberalized criteria to include older and more critically ill candidates. A careful, systematic, multi-disciplinary selection process is critical in identifying potential barriers that may increase risk and optimize long-term outcomes.

Traumatic pseudoaneurysm resulting from ruptured outflow graft due to disconnection of HeartMate II LVAD Bend Relief.

We report a rare case of a 59-year-old male who presented with a pulsating pseudoaneurysm 15 months after placement of a HeartMate II left ventricular assist device (Thoratec Corporation, Pleasanton, CA, USA). Computed tomography and echocardiogram imaging and surgical exploration revealed that bend relief spontaneously detached from the outflow conduit, and the sharp edges of the snap ring component of the bend relief caused perforation to the outflow graft. .

Results of the post-market Registry to Evaluate the HeartWare Left Ventricular Assist System (ReVOLVE).

BACKGROUND: The post-market Registry to Evaluate the HeartWare Left Ventricular Assist System (ReVOLVE) is an investigator-initiated registry established to collect post-CE Mark Trial clinical data on patients receiving a HeartWare ventricular assist device (HVAD) in the European Union and Australia. METHODS: The ReVOLVE is a multi-center, prospective, single-arm registry performed at seven centers in Europe and two in Australia. Herein we describe a total of 254 commercial HVAD implants according to labeled indications between February 2009 and November 2012. Summary statistics included patients' demographics, adverse events, length of support and outcomes. RESULTS: Compared with the clinical trial supporting the CE Mark of the HeartWare system, patient selection differed in that patients were older, and there were higher proportions of females and patients with idiopathic cardiomyopathies in the ReVOLVE cohort. Duration of support ranged from 1 to 1,057 days, with a mean of 363 ± 280 days (median 299.5 days). Transplantation was done in 56 patients (22%), explant for recovery was performed in 3 patients (1%), 43 died while on support (17%), and 152 (60%) remain on the device. Success in patients with the HeartWare system was 87% at 6 months, 85% at 1 year, 79% at 2 years and 73% at 3 years. Adverse event rates were low, comparable or improved when compared to the CE Mark Trial. CONCLUSION: Real-world use of the HeartWare system continues to demonstrate excellent clinical outcomes in patients supported with the device.

The effect of long-term left ventricular assist device support on myocardial sympathetic activity in patients with non-ischaemic dilated cardiomyopathy.

AIMS: Dilated cardiomyopathy (DCM) patients have abundant levels of norepinephrine secondary to failure of the norepinephrine transporter uptake mechanism. Little is known about the effects of an LV assist device (LVAD) on cardiac sympathetic innervations and norepinephrine transporter dysfunction. This study examines the effects of continuous-flow HeartMate II LVAD on cardiac sympathetic innervations using [(123)I]metaiodobenzylguanidine ([(123)I]MIBG) nuclear imaging. METHODS AND RESULTS: After injecting 431 ± 21 MBq of [(123)I]MIBG, planar scintigraphy was performed at 15 min and 4 h in 14 consecutive non-diabetic non-ischaemic DCM patients. Scans were executed early post-LVAD implantation (T1) and prior to either device explantation for myocardial recovery or transplant listing (T2). [(123)I]MIBG measured parameters included early and delayed heart-mediastinum (H/M) ratios and washout rate (W/O). Catecholamine levels were measured using liquid chromatography-mass spectrometry. Following 208.4 ± 85.5 days of LVAD support, both early and delayed H/M ratios increased by 42.1% (P < 0.001) and 54.7% (P < 0.001), respectively. The W/O rate decreased by 46% (P = 0.003). Plasma norepinephrine, epinephrine, and dopamine decreased significantly in correlation with [(123)I]MIBG parameters. Ten patients had recovered and had their device explanted as they had demonstrated a higher percentage change in delayed H/M ratio, W/O rate, and norepinephrine levels. Linear regression analysis revealed a strong correlation between percentage changes in both norepinephrine and epinephrine and myocardial recovery. CONCLUSION: Combination therapy with LVAD and drug resulted in enhancement of [(123)I]MIBG uptake in DCM patients.

Ventricular assist device outflow graft in congenitally corrected transposition of great arteries - a surgical challenge.

Congenitally corrected transposition of the great arteries is a complex congenital cardiac anomaly with a wide spectrum of morphologic features and clinical profiles. Most patients are diagnosed late in their life, undergoes surgical repairs, eventually leading to systemic ventricular failure needing heart transplant or mechanical circulatory assistance. As, aorta is located anterior to and left of the PA (Transposition of great arteries), the outflow graft of ventricular assist device traverse across pulmonary artery to reach aorta which poses challenge during further surgical explorations.

Long-term outcomes of patients bridged to recovery versus patients bridged to transplantation.

OBJECTIVE: The proportion of patients who can be bridged with left ventricular assist devices to myocardial recovery and the long-term outcome of these patients is unknown. METHODS: We investigated the outcomes of patients bridged to recovery compared with those bridged to transplantation. All left ventricular assist devices were implanted as a bridge to transplantation with a very proactive program of promoting myocardial recovery. A total of 40 patients were bridged to recovery and 52 to transplantation. Of the bridged to recovery (explanted) group, 33 were men (age, 32.8 ± 11.8 years), 37 had dilated cardiomyopathy (familial in 3, peripartum cardiomyopathy in 3) and 3 had myocarditis. Of the bridged to transplantation (transplanted) group, 42 were men (age, 42.3 ± 12.5 years; P < .0005 vs bridged to recovery). The diagnosis was ischemic heart disease in 24, dilated cardiomyopathy in 21 (only 13 received drug therapy), hypertrophic obstructive cardiomyopathy in 2, arrythmogenic right ventricular dysplasia in 2, myocarditis in 1, and congestive heart disease in 2. RESULTS: The survival rate was 89.9%, 73.9%, and 73.9% and 80.4%, 78.3, and 78.3% in the explanted and transplanted groups at 1, 5, and 7 years, respectively. In total, 12 (23%) patients bridged transplantation either died from, or required ventricular assist device support, for primary graft failure. Of the explanted patients, 4 (10%) subsequently required transplantation at 34, 512, 1019, and 1213 days (2 died 25 and 1867 days after transplantation and 2 were well after 1523 and 3199 days). The rate of transplant or ventricular assist device-free survival less noncardiac death for the bridged to recovery and bridged to transplantation groups, respectively, was 89.9%, 73.9%, and 73.9% and 80.4%, 78.3%, and 78.3% at 1, 3, and 7 years. At latest follow-up (1394 ± 1195 days for the bridged to recovery and 1913 ± 941 days for the bridged to transplantation group), 5 of the bridged to transplantation patients (9.6%) had malignancy, 34 (65.4%) had hypercholesterolemia, 25 (48.1%) had hypertension, and 7 (13.5%) had coronary disease. The creatinine was 125.5 ± 43.5 vs 95.2 ± 16.5 µmol/L for the bridged to transplantation and bridged to recovery groups (P < .001). CONCLUSIONS: The outcome after explantation for myocardial recovery is comparable, if not better than, after bridge to transplantation.

Multicenter evaluation of an intrapericardial left ventricular assist system.

OBJECTIVES: The aim of this study was to conduct an initial clinical evaluation of the new HeartWare Ventricular Assist System (HeartWare, Inc., Framingham, Massachusetts) in a multicenter, prospective, nonrandomized single-arm clinical trial. BACKGROUND: Heart failure is a worldwide epidemic. The effectiveness of heart transplantation and medical therapy is limited, resulting in the emergence of mechanical circulatory support as a primary treatment for end-stage heart disease. Left ventricular assist devices that use rotary pumps are small and durable, which might reduce morbidity and mortality during support. METHODS: Fifty heart transplant candidates with New York Heart Association functional class IV symptoms were supported at 5 international centers by the HeartWare System for 180 days, until heart transplant, myocardial recovery and device explant, or death. Patients who continue to be supported have been followed for a minimum of 2 years. RESULTS: Of the 50 patients, 20 (40%) received transplants, 4 (8%) had the pump explanted after myocardial recovery, and 17 (34%) continue support at 2 years. Nine (18%) patients died during support from sepsis (n = 3), multiple organ failure (n = 3), or hemorrhagic stroke (n = 3). The actual survival at 6, 12, and 24 months was 90%, 84%, and 79%, respectively. In the survivors, measures of quality of life showed a significant improvement over baseline values. Significant improvements were found for recognition memory at 3 months after implant (p = 0.006). The most frequent adverse events were infection and bleeding. CONCLUSIONS: Patients with end-stage heart failure can be safely and effectively supported by the HeartWare Ventricular Assist System with improved quality of life and neurocognitive function.

Reversal of severe heart failure with a continuous-flow left ventricular assist device and pharmacological therapy: a prospective study.

BACKGROUND: We have previously shown that a specific combination of drug therapy and left ventricular assist device unloading results in significant myocardial recovery, sufficient to allow pump removal, in two thirds of patients with dilated cardiomyopathy receiving a Heartmate I pulsatile device. However, this protocol has not been used with nonpulsatile devices. METHODS AND RESULTS: We report the results of a prospective study of 20 patients who received a combination of angiotensin-converting enzymes, ß-blockers, angiotensin II inhibitors, and aldosterone antagonists followed by the ß2-agonist clenbuterol and were regularly tested (echocardiograms, exercise tests, catheterizations) with the pump at low speed. Before left ventricular assist device insertion, patient age was 35.2 ± 12.6 years (16 male patients), patients were on 2.0 ± 0.9 inotropes, 7 (35) had an intra-aortic balloon pump, 2 were hemofiltered, 2 were ventilated, 3 had a prior Levitronix device, and 1 had extracorporeal membrane oxygenation. Cardiac index was 1.39 ± 0.43 L · min⁻¹ · m⁻², pulmonary capillary wedge pressure was 31.5 ± 5.7 mm Hg, and heart failure history was 3.4 ± 3.5 years. One patient was lost to follow-up and died after 240 days of support. Of the remaining 19 patients, 12 (63.2) were explanted after 286 ± 97 days. Eight had symptomatic heart failure for ≤6 months and 4 for >6 months (48 to 132 months). Before explantation, at low flow for 15 minutes, ejection fraction was 70 ± 7, left ventricular end-diastolic diameter was 48.6 ± 5.7 mm, left ventricular end-systolic diameter was 32.3 ± 5.7 mm, mV(O2) was 21.6 ± 4 mL · kg⁻¹ · min⁻¹, pulmonary capillary wedge pressure was 5.9 ± 4.6 mm Hg, and cardiac index was 3.6 ± 0.6 L · min⁻¹ · m⁻². Estimated survival without heart failure recurrence was 83.3 at 1 and 3 years. After a 430.7 ± 337.1-day follow-up, surviving explants had an ejection fraction of 58.1 ± 13.8, left ventricular end-diastolic diameter of 59.0 ± 9.3 mm, left ventricular end-systolic diameter of 42.0 ± 10.7 mm, and mV(O2) of 22.6 ± 5.3 mL · kg⁻¹ · min⁻¹. CONCLUSIONS: Reversal of end-stage heart failure secondary to nonischemic cardiomyopathy can be achieved in a substantial proportion of patients with nonpulsatile flow through the use of a combination of mechanical and pharmacological therapy.

Echocardiographic assessment of flow across continuous-flow ventricular assist devices at low speeds.

BACKGROUND: Testing of native myocardial function in patients with continuous-flow pumps is challenging as reduction/cessation of the pump could result in regurgitation, although the amount and significance of this regurgitation remains unknown. The aim of this study was to determine the optimal speed at which to assess the native left ventricular (LV) function and the physiologic response to speed reduction. METHODS: Fifteen male patients with a HeartMate II (HMII) device were studied prospectively on 46 occasions. Measurements were performed serially at three device speed settings: baseline speed; 6,000 rpm; and either 5,000 rpm (Group A) or 4,000 rpm (Group B). The device's forward and reverse velocity (Vmax(f), Vmax(r)), forward and reverse velocity time integral (VTI(f), VTI(r)) and blood volume (BV) were also measured using Doppler with LV echocardiographic parameters and peripheral hemodynamics. RESULTS: No adverse incidents were reported. Speed reduction to 6,000 rpm resulted in a significant decrease in Vmax(f), VTI(f) and BV. There was no significant difference in either forward or reverse flow with further speed reduction in either group. Speed reduction to <6,000 rpm did not have a significant effect on LV loading. CONCLUSIONS: Speed reduction in patients with the HMII device is safe. There was no difference between 6,000 rpm and lower speeds, suggesting that 6,000 rpm is sufficient to assess native myocardial function. The absence of significant retrograde filling suggests that LV loading is a physiologic response to speed reduction at 6,000 rpm.

Initial clinical experience with a novel left ventricular assist device with a magnetically levitated rotor in a multi-institutional trial.

BACKGROUND: Third-generation rotary blood pumps have magnetically levitated rotors that eliminate mechanical wear over the years. Together with their potential for miniaturization, these pumps seem suitable for long-term support of patients with a wide range of body surface areas (BSA). Recently, the novel HVAD pump (HeartWare Inc, Framingham, MA), a miniaturized centrifugal pump with a hydrodynamic, magnetically levitated rotor, became ready for clinical application. METHODS: In a multi-institutional trial in Europe and Australia, 23 patients (mean age, 47.9 ± 12 years) in end-stage heart failure were enrolled in 5 centers. The primary end point of the bridge-to-transplant study was survival to heart transplant or survival to 180 days on the device, whichever occurred first. Follow-up data at 1 year are presented. The small size of the device allows for intrapericardial placement of the pump. RESULTS: Implant procedures were generally fast and uneventful. Mean duration of support was 167 ± 143 days (range, 13-425 days), and mean blood flow provided by the pump was 6.1 ± 1.1 liters/min. At the 180-day end point, 2 patients had undergone successful transplant at 157 and 175 days, 2 patients died while on the device, and 19 patients continued pump support for more than 180 days. Actuarial survival after 6 months was 91% and was 86% at the 1-year follow-up. CONCLUSIONS: The design of the HVAD pump enables a quick and less invasive implantation. The results to date demonstrate satisfactory long-term survival with excellent quality of life in this cohort of 23 patients of the initial multi-institutional Conformité Européene (CE) mark trial.