Biventricular Assist Device Patients Research Articles

From Heart Failure via Biventricular Assist Device to Heart Transplantation

Purpose The Berlin Heart® EXCOR biventricular assist device (BVAD) can be used in pediatric as well as adult patients for bridge to heart transplantation (HTX). This study represents the largest population of BVAD implantations in adult patients reported so far. Methods Adult patients (>16 years) receiving a BVAD from 2006-2020 were included. Patient characteristics and outcomes were analyzed in a retrospective single center study. Results Out of the 54 patients, 45 (83%) were male, mean age of 47.4 ± 11.8 years. Mean body mass index (BMI) was 26 kg/m2 with 15 patients >30kg/m2 BMI. INTERMACS classifications were: I =23 patients (43%), II-III = 17 (31%) and IV-V= 14 (26%). Eight patients (14.8) had previous cardiac surgery before BVAD. 30% suffered from ischemic cardiomyopathy. Before BVAD 33 patients (61%) needed temporary MCS (IABP n=14, v-a ECMO n=26; with 7 patients (13%) receiving both). Mean ICU stay after BVAD was 30 days. 26 patients (48%) died on BVAD with mean time to death of 64.6 days. Causes of death were multiple organ failure (27%), septic shock (19%), cerebral hemorrhage (15%), bleeding (11%), cardiogenic shock (11%) and thrombembolic event (8%). In all 54 BVAD patients we performed 83 chamber exchanges. 28 patients were listed as high-urgency (HU) before HTX. Causes for HU-listing were VAD infections (46%, deteriorating HF under BVAD (18%), multiple VAD-related complications (14%), pump thrombosis (7%), stroke (7%), gastrointestinal bleeding (4%) and cardiac arrhythmia (4%). Complications after BVAD and HTX are listed in table 1. Mean time to HTX was 305 days. 30-day-survival after HTX was 96%. 1- and 3-year-mortality were 18 and 30% respectively. Post-HTX causes of death were cardiogenic (27%) and septic shock (36%). Conclusion These retrospective data show secondary organ failure and bleeding represented the main complications under BVAD support. Only 50% of BVAD patients were successfully transplanted but post HTX survival in BVAD patients was comparable to other HTX candidates.

Bridge to heart transplantation in patients with cardiogenic shock: a 20-year experience with two different surgical strategies

We aimed to describe how treatment of patients in cardiogenic shock bridged to heart transplantation with mechanical circulatory support, using either biventricular assist devices (BVADs) or extracorporeal life support (ECLS), has evolved in the last 20 years in our centre. Since 1998, 72 patients with refractory heart failure and indication for heart transplantation have received mechanical circulatory support: 40 had an ECLS system and 32 a BVAD. Early mortality was similar (17.5 vs. 9.4%, P = 0.25) regardless of the type of support. After a median support time of 8 (1-27) vs. 34 (0-385) days (P < 0.01), 70 vs. 65.6% (P = 0.69) of patients underwent transplantation in the two groups. Prior to transplantation, BVAD patients were more stable with lower need for mechanical ventilation (9 vs. 57%, P < 0.01) and dialysis (0 vs. 38%, P < 0.01). Thirty-day mortality after transplantation was similar (18 vs. 14%, P = 0.53). Patients with extracorporeal support had higher rates of renal (P = 0.02) and respiratory failure (P = 0.03), infections (P = 0.02), atrial fibrillation (P = 0.03) and longer ICU stay (P = 0.01). Late survival was similar, while 5-year freedom from coronary vasculopathy was higher in those with BVAD (P = 0.03). Although ECLS provides faster and simpler assistance compared with BVADs, no differences in early and medium-term outcomes in the last 20 years were observed in patients with cardiogenic shock. However, BVADs provided longer duration of support, better multiorgan recovery allowing more adequate graft selection, resulting in a lower rate of posttransplant complications.

The Cost and Length of Stay Associated with Biventricular Assist Devices in the United States (2009-2015)

The purpose of this study was to determine the national trends in utilization, mortality, cost, and length of stay (LOS) associated with implantation of biventricular assist devices (BiVADs) using the National Inpatient Sample (NIS) database. This study was a retrospective analysis of NIS from 2009 to 2015 for surgically implanted internal (n = 538) and external BiVADs (n = 727). Exploratory analyses were performed to explain the trends found in utilization, mortality, cost, and LOS. From 2009 to 2015, the utilization of all BiVADs decreased (4.8% per year, p < 0.001) driven by the decline in utilization of external BiVADs (9.4% per year, p < 0.001). Compared to external BiVADs, internal BiVADs were associated with lower mortality (45.4% vs. 59.1%, p = 0.024), but longer LOS (64.0 vs. 20.0 days, p < 0.001) and higher incidence of renal failure (85.6% vs. 74.0%, p = 0.020). During this time period, there was no significant change in mortality; however, cost and LOS associated with all BiVAD implantations increased significantly. Only those who died during hospitalization had an increase in cost (15% per year, p < 0.001) and LOS (52% per year, p = 0.002) (Figure 1). The latter trends remained significant even after controlling for complications (e.g., gastrointestinal bleed and renal failure) and co-morbidities. The decline in utilization of BiVADs between 2009 and 2015 coincided with the increase in utilization of LVADs during this time. Declining BiVAD utilization can be related to the improvement in the LVAD technology and outcomes as well as the availability of percutaneous temporary circulatory support. Although the advancement in LVAD technology has led to decrease in mortality rate and reduction in cost and LOS, BiVAD mortality remained the same over time with a rise in cost and LOS. Future studies are required to investigate optimal BiVAD configurations and strategies, as well as patient selection in order to improve mortality and reduce LOS and cost for BiVAD patients.

Ventricular arrhythmias in patients with biventricular assist devices.

Ventricular arrhythmias (VAs) are common in patients after left ventricular assist device (LVAD) implant and are associated with worse outcomes. However, the prevalence and impact of VA in patients with durable biventricular assist device (BIVAD) is unknown. We performed a retrospective cohort study of patients with BIVADs to evaluate the prevalence of VA and their clinical outcomes. Consecutive patients who received a BIVAD between June 2014 and July 2017 at our medical center were included. The prevalence of VA, defined as sustained ventricular tachycardia or fibrillation requiring defibrillation or ICD therapy, was compared between BIVAD patients and a propensity-matched population of patients with LVAD from our center. The occurrence of adverse clinical events was compared between BIVAD patients with and without VA. Of the 13 patients with BIVADs, 6 patients (46%) experienced clinically significant VA, similar to a propensity-matched LVAD population (38%, p = 1.00). There were no differences in baseline characteristics between the two cohorts, except patients in the non-VA group who had worse hemodynamics (mitral regurgitation and right-sided indices), had less history of VA, and were younger. BIVAD patients with VA had a higher incidence of major bleeding (MR 3.05 (1.07-8.66), p = 0.036) and worse composite outcomes (log-rank test, p = 0.046). The presence of VA was associated with worse outcomes in both LVAD and BIVAD groups. Ventricular arrhythmias are common in patients with BIVADs and are associated with worse outcomes. Future work should assess whether therapies such as ablation improve the outcome of BIVAD patients with VA.

Ventricular Arrhythmias in Patients with Biventricular Assist Devices

Purpose Ventricular arrhythmias (VAs) are common in patients after left ventricular assist device (LVAD) implant. However, literature on VA after biventricular assist device (BIVAD) placement is limited. We performed a retrospective cohort study of patients with BIVADs to evaluate the prevalence of VA and their clinical outcomes. Methods Consecutive patients who received a BIVAD between June 2014 to July 2017 at University of California San Diego were included. Patients who experienced clinically significant VA were compared to those who did not. We assessed for predictors of VA and clinical endpoints of cardiovascular events. Results Of the 13 patients who received BIVAD (16% ischemic cardiomyopathy), 9 experienced clinically significant VA. Baseline characteristics including age, ejection fraction, and duration of heart failure were similar between the two groups. A prior history of VA predicted patients with VA after BIVAD (100% vs 0%, p Conclusion Ventricular arrhythmias are common in patients with BIVADs and are associated with worse outcomes. Future work should assess whether therapies such as ablation improve the outcome of BIVAD patients with VA.

Successful support of biventricular heart failure patients by new EXCOR® Adult pumps with bileaflet valves: a prospective study.

The Berlin Heart EXCOR® Adult biventricular assist device (BiVAD) is an approved mechanical circulatory support for patients with end-stage biventricular heart failure. In this prospective post-market clinical follow-up study, we present the first clinical experience of the new EXCOR® Adult pump with bileaflet (BL) valves in Europe. After CE-mark approval in August 2014, a total of 12 patients were enrolled with a mean age of 44years ± 11 (range 21-58years). The majority of patients (n = 11) were in INTERMACS level 1 or 2. Eight patients had a median pre-operative extracorporeal life support (ECLS) of 6days (range 1-37days). Primary end point was survival, either to heart transplantation (HTx), recovery or alive at 12months on device, whichever occurred first. Secondary end point was the number of adverse events throughout EXCOR® BiVAD support. Median support time up to last follow-up on EXCOR® BiVAD device was 248days (range 57-381days) and patient survival at 1year was 92%. Half of the EXCOR® BiVAD patients (n = 6) were transplanted and five patients were still on support at 1year post-implantation. Complications during EXCOR® BiVAD support were thoracic bleeding, exit site infection and ischemic cerebrovascular incidents in three cases, respectively. The new EXCOR® Adult pump with BL provides pulsatile high cardiac output with excellent outcome and successful bridging to HTx, particularly in critically ill patients with INTERMACS level 1 or 2at the time of implantation.

HeartWare HVAD for Biventricular Support in Children and Adolescents: The Stanford Experience.

Despite increasing use of mechanical circulatory support in children, experience with biventricular device implantation remains limited. We describe our experience using the HeartWare HVAD to provide biventricular support to three patients and compare these patients with five patients supported with HeartWare left ventricular assist device (LVAD). At the end of the study period, all three biventricular assist device (BiVAD) patients had been transplanted and were alive. LVAD patients were out of bed and ambulating a median of 10.5 days postimplantation. The BiVAD patients were out of bed a median of 31 days postimplantation. Pediatric patients with both left ventricular and biventricular heart failure can be successfully bridged to transplantation with the HeartWare HVAD. Rapid improvement in functional status following HVAD implantation for isolated left ventricular support is seen. Patients supported with BiVAD also demonstrate functional recovery, albeit more modestly. In the absence of infection, systemic inflammatory response raises concern for inadequate support.

High pulmonary vascular resistance in addition to low right ventricular stroke work index effectively predicts biventricular assist device requirement.

Although the right ventricular stroke work index (RVSWI) is a good index for RV function, a low RVSWI is not necessarily an indicator for the need for a right ventricular assist device at the time of left VAD implantation. We here aimed to determine a more precise indicator for the need for a biventricular assist device (BiVAD). In total, 116 patients (mean age, 38 ± 14 years), who underwent hemodynamic assessments preoperatively including 12 BiVAD patients, and had been followed at our institute from 2003 to 2015, were included. Multivariate logistic regression analysis indicated that RVSWI and pulmonary vascular resistance (PVR) were independent predictors of BiVAD requirement (P < 0.05 for both). In addition, all patients were classified into 4 groups: (1) normal (RVSWI > 5 g/m, PVR < 3.7 WU), (2) pulmonary hypertension (RVSWI > 5, PVR > 3.7), (3) RV failure (RVSWI < 5, PVR < 3.7), and (4) both pulmonary hypertension and RV failure (RVSWI < 5, PVR > 3.7), and examined. Most of the patients in Group 4 (75 %), with acutely depressed hemodynamics and inflammatory responses in the myocardium, required BiVAD. Overall, patients with BiVAD had a worse survival rate as compared with those with LVAD alone. In conclusion, high PVR in addition to low RVSWI effectively predicts BiVAD requirement.

Outcomes of biventricular mechanical support patients discharged to home to await heart transplantation.

The use of left ventricular assist devices has grown rapidly in recent years for patients with end-stage heart failure. A significant proportion of patients require both left- and right-sided support with biventricular assist devices (BiVADs) as a bridge to transplantation. Traditionally, these patients have waited in the hospital until they receive a transplant. The aim of this study was to characterize the clinical course of BiVAD patients discharged to home to await heart transplantation. Between November 2009 and July 2011, 24 adult patients underwent Thoratec paracorporeal BiVAD placement at the University of California Los Angeles, all with an Interagency Registry for Mechanically Assisted Circulatory Support score 1 or 2. The disposition, complications, and rehospitalizations of these subjects were retrospectively reviewed. Fourteen of the 24 patients were successfully discharged to home, with a mean time of 60 ± 27 days from BiVAD implantation to discharge. Ninety-three percent (13/14) of the patients sent home went on to be transplanted. Eleven of the 14 (79%) came in from home to receive their transplant. The mean time from BiVAD implantation to transplantation was 100 ± 65 days. Of the 14 patients discharged to home, there were 18 readmissions in 8 patients. In this small single-center review, we found that complex medical patients with BiVADs can be discharged to home and can await a heart transplant from home under the close management of multidisciplinary acute care and outpatient teams.

Invited Commentary

The decision to use a biventricular assist device (BIVAD) versus a left ventricular assist device (LVAD) for a child awaiting transplantation remains difficult. This investigation by Zafar and colleagues [1Zafar F. Jefferies J.L. Tjossem C.J. et al.Biventricular Berlin Heart EXCOR pediatric use across the United States.Ann Thorac Surg. 2015; 99: 1328-1334Google Scholar] from the Berlin Heart EXCOR Pediatric EXCOR study reveals sobering conclusions regarding mechanical assistance in children. In essence, one-third of the patients in this study required BIVAD assistance. The demographic and clinical variables of white race, abnormal glomerular filtration rate, sites with fewer than five implants, and use of the 10-mL pump were identified as predictors of mortality in BIVAD patients. BIVAD support was not associated with improved survival in any identified subset of patients, and survival in BIVAD patients was 60% versus 80% in LVAD patients at 100 days. Although pediatric patients differ from adult patients, a similar inferior survival for BIVAD patients compared with LVAD patients exists for adults [2Cleveland Jr., J.C. Naftel D.C. Reece T.B. et al.Survival after biventricular assist device implantation: an analysis of the Interagency Registry for Mechanically Assisted Circulatory Support database.J Heart Lung Transplant. 2011; 30: 862-869Abstract Full Text Full Text PDF PubMed Scopus (123) Google Scholar]. Although one is tempted to conclude that perhaps BIVAD support should be avoided at all costs, this message is not the appropriate conclusion. As mechanical circulatory support evolves, we must continue to define which patients require BIVAD support and how we can then improve BIVAD outcomes. Clearly, the current study challenges us to question how the current pediatric BIVAD technology might change to improve BIVAD survival. Biventricular Berlin Heart EXCOR Pediatric Use Across the United StatesThe Annals of Thoracic SurgeryVol. 99Issue 4PreviewBiventricular assist device (BiVAD) support was a strong predictor of early mortality in the Berlin Heart EXCOR Pediatric investigational device exemption (IDE) study (Assess Safety and Probable Benefit of the EXCOR Pediatric Ventricular Assist Device [VAD]). In adults, it has been identified that 5% to 10% of the VAD population is benefited by BiVAD support over left ventricular assist device (LVAD) support. An analysis of the Berlin Heart study cohort was performed to characterize patients supported with BiVAD, examine risk factors of mortality in this group, and identify subsets of patients in whom BiVAD is associated with survival. Full-Text PDF

Characterization of ventricular assist device–mediated sensitization in the bridge-to-heart-transplantation patient

Ventricular assist devices (VADs) are associated with increased anti-human leukocyte antigen antibody production. The purpose of this study is to characterize differences in sensitization patterns in patients receiving axial flow, implantable VADs versus pulsatile, paracorporeal biventricular assist devices (BIVADs) as bridges to transplantation. The study is a retrospective review of 68 patients who were bridged to transplantation with either a VAD or a BIVAD, as described, from January 2007 to June 2010, at a university medical center. Five of 15 (33.3%) VAD patients became sensitized during treatment, compared with 30 of 53 (56.6%) BIVAD patients, P=.15. Multivariable analysis comparing BIVAD with VAD, while controlling for previous cardiac surgery, pregnancy, and packed red blood cell transfusion produced an odds ratio of 2.99, P=.14. Of sensitized patients, all 5 (100%) of the VAD patients had pre-existing antibodies before VAD placement, compared with 9 of 30 (30.0%) BIVAD patients, P=.006. Maximum cumulative mean fluorescence intensities for BIVAD were 46,259 ± 66,349 versus 42,540 ± 12,840 for VAD, P=.90. Time to maximum antibody expression was shorter for the VAD group (34 ± 28 days vs 5.8 ± 9 days, P=.04). Device type was not a factor in patient sensitization after implantation. However, VAD patients required pre-existing sensitization before implantation to produce antibodies during their treatment interval, whereas more than two thirds of BIVAD patients developed de novo antibodies. These data suggest that the mechanism of sensitization between VAD and BIVAD patients may differ, and further mechanistic studies into the impact of device types on patient sensitization are warranted.

Invited Commentary

Congratulations to the authors [1]. It is refreshing to find an article in the field of mechanical circulatory support that is scientifically sound and honestly presents a contemporary experience that challenges the current wave of enthusiasm for supporting everyone with continuous-flow left ventricular assist devices (LVADs). This experience is exclusively with pulsatile paracorporeal devices, LVADs and biventricular assist devices (BIVADs). The BIVADs are assist, not replacement, devices. The authors selected BIVAD support preemptively in over half of their patient population and did equally well with the BIVAD group as with the LVADs, even though there was a consistent trend for BIVAD patients to be sicker before implantation (blood urea nitrogen levels higher, INTERMACS [Interagency Registry for Mechanically Assisted Circulatory Support] status sicker, more use of inotropic agents, ejection fraction lower).

Discharge Outcomes in Patients With Paracorporeal Biventricular Assist Devices

As waiting time for heart transplantation has increased, ventricular assist devices have become critical for "bridging" patients with end-stage heart failure. Because most reported post-discharge experience is with left ventricular assist devices (LVAD), we sought to evaluate the safety and feasibility of home discharge on paracorporeal biventricular assist devices (BIVAD). We retrospectively reviewed the hospital course and post-discharge outcomes of 46 consecutive patients who received paracorporeal VADs as bridge to transplant. The success of home discharge was assessed by frequency and reasons for hospital readmission and survival to transplant. Thirty patients (65%) were successfully transferred from the intensive care unit and considered candidates for discharge. Of the 26 patients discharged home, 11 were supported with an LVAD and 15 with BIVADs. Median duration of support until transplant, explant, or death did not differ significantly between LVAD or BIVAD patients (91 days vs 158 days; p = 0.09). There were 26 readmissions for medical or device-related complications; 10 in 7 LVAD patients and 16 in 10 BIVAD patients, with no difference in median length of stay (17 days vs 25 days; p = 0.67). Out of hospital duration of support was similar between LVAD and BIVAD patients (61 days vs 66 days; p = 0.87) as were 6-month and 1-year event-free survival rates (p = 0.49). Outcomes were similar in patients bridged to transplant on home paracorporeal BIVAD versus LVAD support. We recommend discharge for stable patients demonstrating device competency and adequate home care regardless of the need for univentricular or biventricular paracorporeal support.

Combination Evaluation of Preoperative Risk Indices Predicts Requirement of Biventricular Assist Device

Patients with biventricular assist device (BiVAD) placement have a poor prognosis, but preoperative risk factors for the necessity of BiVAD have not been fully elucidated. Data from 79 patients who received left ventricular assist device (LVAD) between November 2002 and December 2011 were retrospectively reviewed. Overall, 9 patients (11.4%) required BiVAD, and the survival rate of BiVAD patients was significantly lower than that of LVAD patients (P<0.001). Multivariate analysis for BiVAD requirement showed left ventricular diastolic diameter (LVDd) ≤62 mm (odds ratio [OR], 10.97; P=0.009) to be significantly associated with BiVAD requirement. Preoperative central venous pressure (CVP)/pulmonary capillary wedge pressure (PCWP) ratio ≥0.5 (OR, 13.09; P=0.028) was also significantly associated with BiVAD requirement. A new scoring system for predicting BiVAD requirement was created from the combination of CVP/PCWP ratio (≥0.5), body surface area (≤1.4 m(2)), preoperative continuous hemodiafiltration use, B-type natriuretic peptide (≥1,200 pg/ml) and LVDd (≤62 mm), and this had a significantly larger area under the curve (0.909; P=0.003) than right ventricular stroke work index on receiver operating characteristic analysis. A score >20 using the new scoring method indicated significantly high probability of BiVAD requirement (OR, 16.00; P=0.019). The new scoring method, which includes CVP/PCWP ratio, is a novel risk stratification tool for BiVAD therapy.

Survival after biventricular assist device implantation: An analysis of the Interagency Registry for Mechanically Assisted Circulatory Support database

Patients requiring biventricular assist device (BiVAD) for mechanical circulatory support (MCS) have substantially worse outcomes than patients requiring left VAD (LVAD) support only. Patient-specific risk factors have yet to be consistently identified in a large, multicenter registry, which may underlie the poorer outcomes for BiVAD patients. The Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) is a registry of U.S. Food and Drug Administration-approved durable MCS devices used for bridge-to-transplantation, destination therapy, or recovery. The purposes of this study were to 1) identify the underlying pre-implant characteristics of the population requiring BiVAD support that contribute to reduced survival, and 2) identify differences in postoperative outcomes with respect to adverse events compared with patients supported with LVAD alone. From June 2006 to September 2009, 1,646 patients were entered into the INTERMACS database in which adverse events and outcomes were recorded for primary implants with LVAD or BiVAD. Competing outcomes methodology was used to estimate the time-related probability of death, transplant, or recovery. Overall survival for all groups was analyzed with Kaplan-Meier methods and Cox proportional regression analysis. The distribution of primary device implants included 1,440 LVADs and 206 BiVADs. BiVAD patients presented with a lower INTERMACS profile 93% in INTERMACS 1 or 2, compared with 73% for LVAD patients (p < 0.001). Survival at 6 months was 86% for LVADs and 56% for BiVADs (p < .0001). Adverse event rates, expressed as episodes/100 patient-months for the BiVAD group compared with LVAD, were significantly higher for infection (33.2 vs 14.3), bleeding (71.6 vs 15.5), neurologic events (7.9 vs 2.6), and for device failure (4.9 vs 2.0). Patients requiring BiVAD support at the time of durable MCS implant are more critically ill at the time of MCS implant. BiVAD patients experience worse survival than patients supported with LVAD alone and higher rates of serious adverse events. Characteristics of the population present at the time of BiVAD implant likely influence post-implant MCS outcomes.