Ventricular Assist Device Group Research Articles

Vascular function in patients with advanced heart failure and continuous-flow or pulsatile ventricular assist devices.

A significant proportion of patients with heart failure (HF) progress to an advanced stage, which is associated with a substantial increase in morbidity and mortality. These patients may be eligible for advanced treatment strategies such as mechanical circulatory support with ventricular assist devices (VAD). Vascular dysfunction is a hallmark of heart failure pathophysiology and prognosis. However, whether and to what degree the hemodynamic benefits of VADs influence vascular function remain unknown. In this study, we evaluated endothelial vascular function with flow-mediated vasodilatation (FMD) and with flicker-light induced retinal vasodilatation (FID). 34 patients with a VAD (age 58 ± 10years, 85% male, 74% ischemic heart disease, 26 continuous-flow (CF)-LVAD, and 8 pulsatile biventricular (bi)-VAD) were compared to 34 propensity-matched patients (mean age 62 ± 9years, 68% male, 59% ischemic heart disease) with advanced HF (AdvHF). Endothelial function of larger arteries (FMD) was significantly better in patients after VAD implantation compared to matched AdvHF patients (7.2 ± 4.6% vs. 5.0 ± 3.2%, p = 0.03), whereas microvascular arteriolar function (FIDart) did not differ (0.99 ± 1.43% vs. 1.1 ± 1.7%, p = 0.78). The arterio-venous ratio (AVR) was higher in the VAD group (0.90 ± 0.06 vs 0.85 ± 0.09, p = 0.01), reflecting wider retinal arteriolar and narrower venular diameters. There was no difference in vascular function between patients with CF-LVAD and pulsatile Bi-VAD. In patients with advanced heart failure, VAD implantation was associated with better endothelial function at the level of large arteries, but not in the microcirculation.

Impact of ventricular assist device use on pediatric heart transplant waitlist mortality: Analysis of the scientific registry of transplant recipients database.

Children awaiting heart transplant (Tx) have a high risk of death due to donor organ scarcity. Historically, ventricular assist devices (VADs) reduced waitlist mortality, prompting increased VAD use. We sought to determine whether the VAD survival benefit persists in the current era. Using the Scientific Registry of Transplant Recipients, we identified patients listed for Tx between 3/22/2016 and 9/1/2020. We compared characteristics of VAD and non-VAD groups at Tx listing. Cox proportional hazards models were used to identify risk factors for 1-year waitlist mortality. Among 5054 patients, 764 (15%) had a VAD at Tx listing. The VAD group was older with more mechanical ventilation and renal impairment. Unadjusted waitlist mortality was similar between groups; the curves crossed ~90 days after listing (p = .55). In multivariable analysis, infant age (HR 2.77, 95%CI 2.13-3.60), Black race (HR 1.57, 95%CI 1.31-1.88), congenital heart disease (HR 1.23, 95%CI 1.04-1.46), renal impairment (HR 2.67, 95%CI 2.19-3.26), inotropes (HR 1.28, 95%CI 1.09-1.52), and mechanical ventilation (HR 2.23, 95%CI 1.84-2.70) were associated with 1-year waitlist mortality. VADs were not associated with mortality in the first 90 waitlist days but were protective for those waiting ≥90 days (HR 0.43, 95%CI 0.26-0.71). In the current era, VADs reduce waitlist mortality, but only for those waitlisted ≥90 days. The differential effect by race, size, and VAD type is less clear. These findings suggest that Tx listing without VAD may be reasonable if a short waitlist time is anticipated, but VADs may benefit those expected to wait >90 days.

Perioperative Morbidity and Outcomes in Pediatric Patients Transitioned From Extracorporeal Membrane Oxygenation to Ventricular Assist Device Support: A Study of the Society of Thoracic Surgeons Congenital Heart Surgery Database.

As a bridge to transplant strategy, children transitioned from extracorporeal membrane oxygenation (ECMO) to ventricular assist device (VAD) have higher waitlist mortality compared with those who receive de novo VAD. However, the contribution of the immediate perioperative period and differences in the two groups are not well studied. We performed a nested case-control study between children receiving de novo VAD (group 1) and those transitioned from ECMO to VAD (group 2) between 2014 and 2019 using The Society of Thoracic Surgeons (STS) database. A total of 735 children underwent VAD placement with 498 in group 1 and 237 in group 2. Patients in group 2 were significantly younger, smaller, and significantly sicker, were twice as likely to transition to biventricular VAD and need unplanned reoperations. Overall mortality was 16% for group 1 and 34% for group 2 ( p < 0.01). Regression analysis showed that ECMO use (odds ratio [OR], 2.17 [1.3-3.4]), ventilator need (OR, 2.2 [1.3-3.9]), and cardiogenic shock (OR, 1.8 [1.2-2.8]) were all independent preoperative predictors of VAD mortality while dialysis need (OR, 25.5 [8.6-75.3]), stroke (OR, 6.2 [3.1-12.6]), and bleeding (OR, 1.9 [1.1-3.4]) were independent postoperative predictors of VAD mortality within 30 days (all p < 0.05). The study demonstrated significant baseline differences between the two cohorts, warranting avoidance of comparison. Early elective VAD placement in this cohort of patients should be sought to avoid interim ECMO and high post-VAD mortality.

Expanding the heart donor pool: Can left ventricular assist devices substitute for marginal donor heart allografts?

BackgroundGenerally, heart transplantation with marginal donor allografts is reserved for a subset of high-risk patients. However, given the improved survival rates for patients on left ventricular assist devices, it is worth analyzing if they could potentially substitute for marginal donor allografts. This study aimed to compare survival outcomes of waitlisted patients with left ventricular assist devices who did not undergo heart transplantation to those who underwent heart transplantation with marginal allografts. MethodsThis was a retrospective cohort study of adults (≥18 years) listed for heart transplantation between 2010 and 2022 in the Organ Procurement and Transplantation Network database. A previously validated risk score was used to define marginal donor organs. The primary outcome was death after transplantation or on the waitlist, as appropriate. ResultsOf 5,713 patients with left ventricular assist devices, 4,683 (82%) comprised the left ventricular assist devices group and 1,030 (18%) the marginal group. The marginal cohort was older (57 [49–64] vs 55 [45–62] years, P < .001), similarly female (26 vs 24%, P = .16), and less often White (51 vs 60%, P < .001). Relative to the left ventricular assist devices group, the marginal group demonstrated higher 5-year survival from 2010 to 2014 (81 vs 43%, P < .001) and from 2015 to 2019 (77 vs 66%, P < .001). After adjustment, marginal patients demonstrated a significantly reduced hazard of 5-year mortality for those listed from 2010 to 2014 (hazard ratio 0.25, confidence interval 0.20–0.31; P < .001) and from 2015 to 2019 (hazard ratio 0.46, confidence interval 0.37–0.57; P < .001). ConclusionOur study validates the superiority of transplantation relative to left ventricular assist devices but also underscores the survival benefit of heart transplantation with marginal donor allografts, even in high-risk patients.

Abstract 9709: Impact of Ventricular Assist Device Use on Pediatric Heart Transplant Waitlist Mortality: Analysis of the SRTR Database

Introduction: Children in need of heart transplant (Tx) have a high risk of death on the Tx waitlist due to scarcity of donor organs. Studies of previous eras have shown that ventricular assist devices (VADs) reduce waitlist mortality. We sought to determine whether a survival benefit for VAD patients persists in the current Tx allocation system. Methods: Using the Scientific Registry of Transplant Recipients database, we identified patients listed for primary Tx between 3/22/2016-9/1/2020. Characteristics at time of Tx listing were compared between VAD and non-VAD groups. Cox proportional hazards models were used to identify risk factors for one-year Tx waitlist mortality. Results: Among 5,054 total patients, 764 (15%) had a VAD at time of Tx listing. The VAD group was older, heavier, and had higher prevalence of cardiomyopathy, mechanical ventilation (MV), and impaired renal function. Unadjusted waitlist mortality was similar between the VAD and non-VAD groups (p=0.55, Figure), with the curves crossing ~90 days after listing. A multivariable Cox model showed infant age (HR 2.94, 95% CI 2.26-3.81), Black race (HR 1.59, 95% CI 1.33-1.90), congenital heart disease (HR 1.37, 95% CI 1.56-1.62), renal impairment (HR 2.62 95% CI 2.15-3.19), IV inotropes (HR 1.19, 95% CI 1.01-1.40) and MV (HR 2.58, 95% CI 2.13-3.13), were associated with one-year waitlist mortality. VAD use was not associated with mortality in the first 90 days after Tx listing (HR 0.87, 95% CI 0.65-1.18) but was protective for those waiting ≥90 days (HR 0.40, 95% CI 0.24-0.66). Conclusions: VADs reduce waitlist mortality in the current era, but only for those waiting ≥90 days after Tx listing. Potentially modifiable risk factors, including MV and renal impairment, are associated with mortality. These findings suggest that Tx listing without VAD may be a reasonable option if a short waitlist time is anticipated. However, VAD use may confer benefits, particularly for those expected to wait more than 90 days.

Effect of preoperative extracorporeal membrane oxygenation therapy on postventricular assist device outcomes: an analysis of the STS Pedimacs database.

Extracorporeal membrane oxygenation (ECMO) support prior to ventricular assist device (VAD) therapy is frequently used for stabilizing INTERMACS 1 and 2 paediatric patients. Data regarding outcomes with this strategy is limited. Patient characteristics and outcomes post-VAD therapy with and without preop ECMO support were compared. Survival and risk factor analysis was performed for all patients and INTERMACS profile 1 subgroup. Of 541 INTERMACS 1 and 2 patients enrolled in Paediatric Interagency Registry for Mechanical Circulatory Support registry, 391 received primary VAD implantation and ECMO prior to VAD therapy was utilized in 150 patients. Younger age (P < 0.0001) and shock (P < 0.0001) were more common in group 2, with lower survival at 1, 6 and 12 months compared to group 1 (P < 0.0001). Freedom from infection (P = 0.03) was higher in group 1. Freedom from stroke (P = 0.7) was similar. Paracorporeal continuous flow devices led to poor survival in both groups 1 and 2 (P = 0.4). Implantable continuous flow (P < 0.0001) and paracorporeal pulsatile devices (P = 0.007) had better survival in primary VAD group. INTERMACS profile 1, lower weight, hepatic dysfunction, renal failure, paracorporeal continuous and percutaneous devices were associated with higher mortality. Preop ECMO therapy was not associated with higher mortality (P = 0.12). Survival of INTERMACS profile 1 patient was similar at 1, 6 and 12 months in both groups (P = 0.1). INTERMACS profile 1, lower weight, hepatic dysfunction, renal failure and use of paracorporeal continuous flow or percutaneous assist devices are associated with a higher postoperative mortality. Preop ECMO therapy however is not independently associated with higher postop mortality.

Left Ventricular Support for Unprotected Left Main Coronary Artery Interventions (The Dayton Heart and Vascular Impella Registry).

Coronary artery bypass grafting is the standard of care for patients with obstructive left main (LM) coronary disease. In poor surgical candidates, high-risk percutaneous coronary artery intervention (PCI) is an alternative. We investigated a retrospective cohort of patients who underwent LM PCI from January 2010 to March 2014 (n = 89). Obstructive LM disease was defined as 50% angiographic obstruction of luminal flow, and the primary endpoint was inhospital mortality. Ventricular assist device (VAD) was defined as the use of either intra-aortic balloon pump (IABP) or Impella 2.5 devices before, during, or following PCI. A total of 89 patients with LM PCI were divided into those with (n = 39) and without (n = 50) VAD support. The former group was further divided into those with support from either Impella 2.5 (n = 28) or IABP (n = 11). Age, race, and gender did not differ between patients who received unassisted LM-PCI from those with VAD support (P = 0.142, 1.0, and 0.776, respectively). The angiographic stenosis of atherosclerotic lesions in LM, proximal left anterior descending artery, and other native/surgical coronary vessels was similar between the groups. The duration of hospitalization was significantly longer for patients with VAD support compared to those without (7.19 ± 6.89 vs. 2.78 ± 3.39, P < 0.001). The incidence of cardiogenic shock and inhospital mortality was significantly higher in the VAD group (P = 0.009 and 0.001, respectively). Overall, inhospital mortality was 9% (8/89). The IABP and Impella 2.5 groups had mortality proportions of 46% (5/11) and 11% (3/28), respectively; P = 0.028. For all patients, inhospital mortality was higher for those with versus without cardiogenic shock (56% or 5/9 vs. 4% or 3/80; P < 0.001), and for those with versus without left ventricular systolic function <40% (17% vs. 2%;P < 0.025). In a selected group of patients with LM disease, unsupported PCI appears to be a feasible and safe procedure. In high-risk patients, the use of Impella 2.5 appears to be superior to IABP in LM PCI resulting in favorable short-term outcomes.

Perioperative Morbidity and Outcomes of Transitioning from ECMO to VAD Support in Pediatric Patients: A STS Study

<h3>Purpose</h3> As a bridge to transplant strategy, children transitioned from ECMO to VAD (ventricular assist device) have higher waitlist mortality compared to those who receive de novo VAD. However, the reasons and timing for such additive morbidity and mortality are unclear. We therefore studied the acute perioperative morbidity and mortality in de novo VAD (group 1) to those transitioned from ECMO to VAD (group 2) using the comprehensive data from The Society of Thoracic Surgeons (STS) database. <h3>Methods</h3> Pediatric patients receiving VAD between 2014-19 reported to STS database were identified and selected based on surgical codes and device specifications. Patients were then divided into group 1 and 2 and perioperative data analyzed using appropriate statistical tests. <h3>Results</h3> A total of 735 children underwent VAD placement with 498 in group 1 and 237 in group 2. Patients in group 2 were significantly younger, smaller, were in cardiogenic shock or have CPR. Patients in group 2 also were significantly likely to have hepatic, renal and neurologic dysfunction at baseline and be three times as likely to be on ventilator (all p <0.001, Table 1). Group 2 patients were twice as likely to transition to biVAD compared to group 1. Post-operative course was significant for unplanned reoperations in 8% group 1 versus 34% in group 2 (p<0.001). VAD related complications were similar after VAD implantation in both groups except intracranial bleeding in 4% for group 1 while 13% for group 2 (p<0.01). Overall mortality was 16% for group 1 and 34% for group 2 (p<0.01). Regression analysis showed that ECMO use (OR 2.17), ventilator (OR 2.2), cardiogenic shock (OR1.8) were all independent preoperative predictors of VAD mortality while renal failure, stroke and bleeding were independent post-operative predictors of VAD mortality within 30 days. <h3>Conclusion</h3> There are significant baseline differences in the cohorts undergoing de novo VAD compared to those transitioned from ECMO, however the need for such ECMO is an important predictor of early post VAD mortality. Therefore, early and elective VAD placement in this cohort of patients should be sought to avoid high post-VAD mortality. Comparison of these two strategies should be avoided without accounting for baseline differences while optimal type and timing of support is researched.

Efficacy of a temporary CentriMag ventricular assist device in acute fulminant myocarditis patients revived with extracorporeal cardiopulmonary resuscitation

Although extracorporeal life support (ECLS) can provide emergency systemic perfusion for acute fulminant myocarditis (AFM), the mortality rate remains extremely high, especially in those undergoing extracorporeal cardiopulmonary resuscitation (ECPR). Temporary ventricular assist device (VAD) can provide a more physiological blood flow direction and better subsequent organ perfusion than ECLS. We investigated temporary VAD efficacy in ECPR-revived AFM patients. During January 2012-May 2019, we retrospectively recruited 22 AFM patients with hemodynamic collapse and ECPR; 11 underwent ECLS only and 11 underwent additional VAD support after ECLS. Systemic perfusion was compared via laboratory biochemistry at post-ECPR days 2 (D2) and 4 (D4). Consciousness and cardiac function were assessed through the Glasgow Coma Scale (GCS) and echocardiography, respectively. All major complications and causes of mortality were recorded; 30-day survival was analyzed and risk factors were predicted. The VAD group had significantly better hemodynamic improvement; more inotropes being tapered at D2 and D4; better data representative of systemic perfusion, including albumin, pH, bicarbonate, and lactate levels at D4; and better 30-day survival (72.7% vs. 27.2%, p=0.033). The causes of mortality included central failure, multiple organ failure, and bacteremia with sepsis. The risk factors included lethal dysrhythmia before ECLS, GCS <5at D2, and elevated cardiac enzymes at D4. For AFM patients, temporary VAD could provide better systemic perfusion and organ preservation than ECLS. VAD had better survival, including improved recovery and successful transplantation. Hence, temporary VAD should be considered if ECLS cannot revive the sustained cardiogenic shock.

Right and left ventricular assist devices are an option for bridge to heart transplant

BackgroundPatients with a left ventricular assist device with right ventricular failure are prioritized on the heart transplant waitlist; however, their post-transplant survival is less well characterized. We aimed to determine whether pretransplant right ventricular failure affects postoperative survival in patients with a left ventricular assist device as a bridge to transplant. MethodsWe performed a retrospective review of the 2005-2018 Organ Procurement and Transplantation Network/United Network for Organ Sharing registry for candidates aged 18 years or more waitlisted for first-time isolated heart transplantation after left ventricular assist device implantation. Candidates were stratified on the basis of having right ventricular failure, defined as the need for right ventricular assist device or intravenous inotropes. Baseline demographic and clinical characteristics were compared among the 3 groups, and post-transplant survival was assessed. ResultsOur cohort included 5605 candidates who met inclusion criteria, including 450 patients with right ventricular failure, 344 patients with a left ventricular assist device and intravenous inotropes as a bridge to transplant, 106 patients with a left ventricular assist device and right ventricular assist device, and 5155 patients with a left ventricular assist device as a bridge to transplant without the need for right side support. Compared with patients without right ventricular failure, patients with a left ventricular assist device as a bridge to transplant with right ventricular failure were younger (median age 51 years, 55 vs 56 years, P < .001) and waited less time for organs (median 51 days, 93.5 vs 125 days, P < .001). These patients also had longer post-transplant length of stay (median 18 days, 20 vs 16 days, P < .001). Right ventricular failure was not associated with decreased post-transplant long-term survival on unadjusted Kaplan–Meier analysis (P = .18). Neither preoperative right ventricular assist device nor intravenous inotropes independently predicted worse survival on multivariate Cox proportional hazards analysis. However, pretransplant liver dysfunction (total bilirubin >2) was an independent predictor of worse survival (hazard ratio, 1.74; 95% confidence interval, 1.39-2.17; P < .001), specifically in the left ventricular assist device group and not in the left ventricular assist device + right ventricular assist device/intravenous inotropes group. ConclusionsPatients with biventricular failure are prioritized on the waiting list, because their critical pretransplant condition has limited impact on their post-transplant survival (short-term effect only); thus, surgeons should be confident to perform transplantation in these severely ill patients. Because liver dysfunction (a surrogate marker of right ventricular failure) was found to affect long-term survival in patients with a left ventricular assist device, surgeons should be encouraged to perform transplantation in these severely ill patients after a recipient's optimization by inotropes or a right ventricular assist device because even when the bilirubin level is elevated in these patients (treated with right ventricular assist device/inotropes), their long-term survival is not affected. Future studies should assess recipients' optimization before organ acceptance to improve long-term survival.

Contemporary outcomes of durable ventricular assist devices in adults with congenital heart disease as a bridge to heart transplantation.

This study aimed to compare the clinical characteristics, risk factors, and overall survival outcomes in adults with congenital heart disease (ACHD) bridged to transplantation with a ventricular assist device (VAD) versus no-VAD. The study included 894 ACHD patients aged ≥18years listed for primary heart transplantation between 2010 and 2019 from the United Network for Organ Sharing database. Primary outcomes were waitlist and 1-year post-transplant mortality between VAD and no-VAD ACHD patients. Of 894 ACHD patients included in the study, 91(10.1%) had VAD support at the time of listing. Patients who needed VAD support were mostly males, heavier, and had higher pulmonary artery pressure than the no-VAD group at the listing. The overall waitlist mortality was 38% in the VAD group than 17% in the no-VAD group (p<0.01). ECMO use was associated with significantly higher mortality than either group. There was no significant difference in 1-year post-transplant mortality between VAD versus no-VAD at the time of transplant (15% vs. 17%; p=0.66). Multivariate regression analysis found that BMI <20kg/m2 (hazard ratio (HR) 1.1; p=0.01), bilirubin >2mg/dl (HR 1.1; p=0.03), creatinine >2mg/dl (HR 1.3; p=0.04) and ECMO at transplant (HR 1.4; p=0.03) increased early post-transplant mortality. The one-year post-transplant mortality rate was no different for ACHD patients that received VAD versus no-VAD. These findings suggest that a VAD should be considered an option to support ACHD patients as a bridge to heart transplantation.

The Effect of Infectious Complications During Ventricular Assist Device Use on Outcomes of Pediatric Heart Transplantation.

To describe the impact of infectious adverse events (IAEs) during ventricular assist device (VAD) support on graft loss, infection, and rejection after pediatric heart transplant (HT). Pedimacs data were linked to Pediatric Heart Transplant Society (PHTS) data for patients receiving a VAD followed by HT between September 2012 and December 2016. Linked patients were categorized into IAE on VAD (group A) and no IAE on VAD (group B). Infectious adverse event locations included nondevice, device (external or internal), and sepsis. Post-HT outcomes for analysis were graft loss, infection, and rejection. Time-dependent analysis included Kaplan-Meier and multiphase parametric hazard function analysis. We linked 207 patients (age 9.4 ± 6.3 years). Post-HT follow-up was 19.4 patient-months (<8 days-4.1 years). Group A included 42 patients (20%) with 62 IAEs. Group B included 165 patients without an IAE. Group A patients were younger (7.4 ± 6.1 vs. 9.5 ± 6.3 years; p = 0.03), waited longer for HT (5.3 ± 4.1 vs. 2.9 ± 2.5 months; p = 0.0005), and were hospitalized longer post-HT (42 ± 59 vs. 23 ± 22 days; p = 0.05). VAD-related IAEs were rare (N = 11). Groups A and B had similar freedom from first post-HT infection, rejection, and graft loss (all p > 0.1). However, patients with VAD-related IAE were somewhat more likely to experience rejection (p = 0.03) and graft loss (p = 0.01). Children with an IAE on VAD who survive to HT are younger, wait longer for HT, and remain hospitalized longer than those without an IAE on VAD. Overall, IAE on VAD did not impact post-HT outcomes, but VAD-related IAE may be associated with graft loss and rejection.

Pediatric Heart Transplant Recipients Bridged with Biventricular Assist Device Have Worse 1 Year Graft Survival.

There are little data on postheart transplant (HT) outcomes for pediatric patients that were supported to HT with biventricular assist device (BiVAD). The United Network for Organ Sharing database was queried for patients <18 years old at time of HT between January 2005 and March 2018, excluding patients bridged with total artificial hearts and right ventricular assist device (VAD). Of 4,904 pediatric HT recipients, patients were grouped by no VAD support (3,934; 80.2%), left ventricular assist device only (736; 15%), and BiVAD (234; 4.8%). Overall graft survival analysis indicates crossing hazard rates between groups over time with the BiVAD group having a significantly lower graft survival at 1 year post-HT. A Cox model adjusted for age, era, diagnosis, and time by group interaction demonstrated increased 1 year hazard ratio (HR) of 8.5 (95% confidence intervals [CI]: 6.15-11.79) comparing BiVAD to no VAD. Comparable hazard between BiVAD and no VAD groups were found at 5 years (HR 1.01; 95% CI: 0.67-1.51), while lower hazard for the BiVAD group was found at 10 years post-HT (HR 0.07; 95% CI: 0.03-0.18). Although pre-HT BiVAD support leads to worse graft survival 1 year post-HT, long-term survival is acceptable.

Ventricular assist devices and middle age reduce heart transplantation rates for waitlist candidates.

Ventricular assist devices (VADs) are commonly employed as a bridge to transplantation for heart failure. The full effects of VADs on transplantation rates are not fully understood. We sought to compare transplantation rates stratified by age and VAD status. Using the Organ Procurement and Transplantation Network (OPTN) database, we investigated the impact of age and VAD status on heart allocation rates among all transplant-eligible patients from January 2005 to September 2018. Patients were grouped based on the presence (+) or absence (-) of a VAD as well as age (<45, 45-65, and >65 years). Demographics were compared with a multivariate competing risk analysis that yielded risk-adjusted subdistribution hazard ratios (SHR). Among the 50 602 total waitlist candidates, 18 271 patients with a VAD had higher rates of diabetes and cerebrovascular disease at waitlist entry. Multivariate analysis found statistically significant lower rates of transplantation for all (+)VAD groups compared with age-matched (-)VAD counterparts, with the 45- to 65-year-old (+)VAD group having the lowest transplantation rate (SHR = 0.62; P < .0005). Among (-)VAD patients, transplantation rates increased with increase in age. There is a statistically significant reduced rate of transplantation for patients with a VAD compared with those without a VAD, with the lowest rate among those of ages 45 to 65 years with a VAD. The increasing prevalence of this demographic and the deprioritization of VADs in the new heart allocation criteria have the potential to further exacerbate this difference.

Left Ventricular Filling Pressures Contribute to Exercise Limitation in Patients with Continuous Flow Left Ventricular Assist Devices.

We sought to determine hemodynamic mechanisms of exercise intolerance in a group of patients with the HeartWare ventricular assist device (VAD) compared to a group of heart failure patients. Twenty VAD and 22 heart failure patients underwent symptom-limited active straight leg raising exercise during right heart catheterization with thermodilution (TD), and upright cycling cardiopulmonary stress testing with cardiac output measurement by inert gas rebreathing (IGR) method. The TD and IGR exercise cardiac indexes were higher in VAD compared with heart failure group (both P < 0.05), although there was only a borderline increase in peak exercise oxygen consumption (VO2) (P = 0.06). Baseline and exercise right heart catheterization pressures were not significantly different between the two groups. The only significant independent predictors of peak VO2 in the heart failure group were exercise heart rate and cardiac index (both P < 0.05). In contrast, for the VAD group only, resting pulmonary arterial wedge and pulmonary arterial mean pressures were independently related to peak VO2 (both P < 0.05). Thus, in heart failure, exercise cardiac index is an important limitation to exercise capacity, and VADs increase exercise cardiac index. However, in VAD patients, this only produces limited benefits as increased pulmonary and pulmonary wedge pressures limit increases in exercise capacity.

Early and long-term results of heart transplantation with reoperative sternotomy.

This study aims to investigate the effects of reoperative sternotomy on early and long-term outcomes after heart transplantation. We retrospectively reviewed data of a total of 92 patients (72 males, 20 females; mean age 36 years; range, 3 to 61 years) who underwent orthotopic heart transplantation between May 1998 and July 2014. The patients were divided into three groups. Group A (n=23) included patients who underwent previous cardiac surgery with sternotomy other than ventricular assist device implantation; Group B (n=12) included patients who were bridged-to-transplant with a ventricular assist device; and Group C (n=57) included patients who for the first time underwent heart transplantation without previous sternotomy. Preoperative and operative data of the three groups were compared. The short- and long-term outcomes of all groups were analyzed. There was no significant difference among the groups, except for the age and preoperative international normalized ratio. Total ischemia time in the ventricular assist device group was longer than Group C. The length of intensive care unit stay was also longer in the ventricular assist device group than the other groups. The amount of postoperative chest tube drainage and blood transfusion was higher in Group A. Early mortality rate was significantly higher in Group A. There was no significant difference in survival among the three groups in the long-term. According to the logistic regression analysis, no variable was found to be a significant risk factor for mortality. Reoperative sternotomy other than ventricular assist device implantation was found to be a risk factor for early mortality; however, mid and long-term survival rates were similar to patients in whom transplantation was the primary procedure. In patients with reoperative sternotomy, heart transplantation can be performed with similar risks to patients without resternotomy with careful selection and accurate pre- and intraoperative surgical approach.

Early outcomes with durable left ventricular assist device replacement using the HeartMate 3

BackgroundThe HeartMate 3 (HM3) left ventricular assist device (LVAD) (Abbott, Inc, Chicago, Ill) is a fully magnetically levitated centrifugal implantable pump used to treat patients with chronic heart failure. The MOMENTUM (Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy With HeartMate 3) trial demonstrated that patients treated with the HM3 experienced reduced need for reoperation for LVAD replacement compared with a control group receiving an axial flow design, Heartmate II (Abbott, Inc). However, there are few reports of using HM3 as the replacement pump in patients who already are supported by a durable LVAD and experience a device-related complication necessitating replacement. MethodsAn institutional LVAD database was used to identify 19 consecutive patients who underwent pump replacement to HM3 (group 1) versus 85 consecutive control patients who underwent pump replacement to either Heartmate II or HeartWare Ventricular Assist Device (Medtronic Inc, Minneapolis, Minn) (group 2), at a single institution from January 2010 to August 2018. Patient baseline characteristic and outcomes were obtained from a prospectively maintained database. The primary endpoint was a composite of freedom from death or need for another replacement surgery. ResultsThere was no difference between the groups in heart failure etiology, indication for replacement, as well as the average days on the previous pump or the type of previous pump. The HM3 group did have a significantly greater body mass index (37 vs 31.6 P = .01), a greater number of previous LVAD implants (36.8% vs 5.9%, had 2 previous LVADs, P < .001), and a greater number of previous sternotomies (31.6% vs 7.1%, had 3 previous sternotomies, P = .001). No difference was found between the groups in terms of postoperative adverse event rates. With regards to the primary endpoint, the patients with HM3 replacements (group 1) versus group 2 experienced significantly greater freedom from either death or need for another replacement during the follow-up period (P = .039). During follow-up, there were no thrombosis events for the patients who received replacement with HM3. ConclusionsLVAD replacement with HM3 can be performed safely and may be considered as the pump of choice in patients requiring LVAD replacement.

Long-term outcome of heart transplantation performed after ventricular assist device compared with standard heart transplantation

Data on the long-term outcome of heart transplantation in patients with a ventricular assist device (VAD) are scarce. To evaluate long-term outcome after heart transplantation in patients with a VAD compared with no mechanical circulatory support. Consecutive all-comers who underwent heart transplantation were included at a single high-volume centre from January 2005 until December 2012, with 5 years of follow-up. Clinical and biological characteristics, operative results, outcomes and survival were recorded. Regression analyses were performed to determine predictors of 1-year and 5-year mortality. Fifty-two patients with bridge to transplantation by VAD (VAD group) and 289 patients transplanted without a VAD (standard group) were enrolled. The mean age was 46±11 years in the VAD group compared with 51±13 years in the standard group (P=0.01); 17% of the VAD group and 25% of the standard group were women (P=0.21). Ischaemic time was longer in the VAD group (207±54 vs 169±60minutes; P<0.01). There was no difference in primary graft failure (33% vs 25%; P=0.22) or 1-year mortality (17% vs 28%; P=0.12). In the multivariable analysis, preoperative VAD was an independent protective factor for 1-year mortality (odds ratio 0.40, 95% confidence interval 0.17-0.97; P=0.04). Independent risk factors for 1-year mortality were recipient age>60 years, recipient creatinine, body surface area mismatch and ischaemic time. The VAD and standard groups had similar long-term survival, with 5-year mortality rates of 35% and 40%, respectively (P=0.72). Bridge to transplantation by VAD was associated with a reduction in 1-year mortality, leading critically ill patients to similar long-term survival compared with patients who underwent standard heart transplantation. This alternative strategy may benefit carefully selected patients.

Implication of Ventricular Assist Devices in Extracorporeal Membranous Oxygenation Patients Listed for Heart Transplantation.

The new allocation criteria classify patients on veno-arterial extracorporeal membranous oxygenation (VA-ECMO) as the highest priority for receiving orthotopic heart transplantation (OHT) especially if they are considered not candidates for ventricular assist devices. The outcomes of patients who receive ventricular assist devices (VADs) after being listed for heart transplantation with VA-ECMO is unknown. We analyzed 355 patients listed for OHT with VA-ECMO from the United Network for Organ Sharing database from 2006 to 2014. Univariate and multivariate Cox proportional-hazards models were used to determine the contribution of prognostic variables to the outcome. Thirty-three patients (9.3%) received VADs (15 dischargeable, 7 non-dischargeable VADs). The VAD and non-VAD groups had similar listing characteristics except that the VAD group were more likely to have non-ischemic cardiomyopathy (48.5% vs. 25.2%), and less likely to be obese (6.1% vs. 25.2%) or have a history of prior organ transplant (3% vs. 31.1%). Patients who underwent VAD implantation had more days on the list (median 189 vs. 14 days) compared to the non-VAD group. Amongst the patients who had VADs, (25/33) 75.5% patients were subsequently transplanted with similar post-transplant survival compared to the non-VAD group (72% vs. 60.5%; p = 0.276). Predictors of one-year post-transplant mortality included panel reactive antibodies (PRA) class I ≥ 20%, recipient smoking history, increased serum creatinine and total bilirubin. Therefore, a small proportion of patients listed for transplantation with VA ECMO undergo VAD implantation. Their waitlist survival is better than non-VAD group but with similar post-transplant survival.

Revealing a new mode of sensitization induced by mechanical circulatory support devices: Impact of anti‐AT1R antibodies

Increased levels of angiotensin II type 1 receptor (AT1 R) antibody have been shown to be associated with allograft rejection. This study aims to determine the rate of development of antibody to AT1 R after mechanical circulatory support device (MCS) implantation, and if the development of strong binding AT1 R antibodies is associated with survival. Eighty-eight patients who had one MCS implantation were accessed based on serum availability. Mechanical circulatory support devices in this cohort included pneumatic bilateral paracorporeal ventricular assist device, continuous flow left ventricular assist device, and total artificial heart. Of 88 patients, seven patients had AT1 R antibodies ≥40U/mL preimplantation. For 81 patients who had AT1 R antibodies <40U/mL, the median value was 8U/mL. Of these 81 patients, AT1 R antibody levels in 55 (68%) patients reached the saturated concentration (≥40U/mL) postimplantation (P<.0001), with the highest percentage of patients with the saturated level of AT1 R antibody observed in the pneumatic bilateral paracorporeal ventricular assist device group. Compared to patients without the saturated level of AT1 R antibodies, patients with the saturated AT1 R antibody level had lower 18-month survival (P=.040). Mechanical circulatory support devices implantation significantly increases AT1 R antibody levels. The saturated level of AT1 R antibodies is associated with lower patient survival postimplantation.