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HeartMate 3 is the only durable left ventricular assist devices (LVAD) currently implanted in the United States. The purpose of this study was to develop a predictive model for 1 year mortality of HeartMate 3 implanted patients, comparing standard statistical techniques and machine learning algorithms. Adult patients registered in the Society of Thoracic Surgeons, Interagency Registry for Mechanically Assisted Circulatory Support (STS-INTERMACS) database, who received primary implant with a HeartMate 3 between January 1, 2017, and December 31, 2019, were included. Epidemiological, clinical, hemodynamic, and echocardiographic characteristics were analyzed. Standard logistic regression and machine learning (elastic net and neural network) were used to predict 1 year survival. A total of 3,853 patients were included. Of these, 493 (12.8%) died within 1 year after implantation. Standard logistic regression identified age, Model End Stage Liver Disease (MELD)-XI score, right arterial (RA) pressure, INTERMACS profile, heart rate, and etiology of heart failure (HF), as important predictor factors for 1 year mortality with an area under the curve (AUC): 0.72 (0.66-0.77). This predictive model was noninferior to the ones developed using the elastic net or neural network. Standard statistical techniques were noninferior to neural networks and elastic net in predicting 1 year survival after HeartMate 3 implantation. The benefit of using machine-learning algorithms in the prediction of outcomes may depend on the type of dataset used for analysis., Competing Interests: M.L. discloses grants and consulting fees for Abbott and Abiomed. S.L. discloses support from Abbott to attend the Heart Failure User’s meetings in May 2022 and October 2019. R.Y.L.-R. discloses support from Abbott to attend an educational meeting in August 2023. The other authors have no conflicts of interest to report., (Copyright © ASAIO 2023.)

Background: Left ventricular assist device (LVAD) is associated with a high incidence of right ventricular (RV) failure, which is hypothesized to be caused by the occurring inter-ventricular interactions when the LV is unloaded. Factors contributing to these interactions are unknown., Methods: We used computer modeling to investigate the impact of the HeartMate 3 LVAD on RV functions. The model was first calibrated against pressure-volume (PV) loops associated with a heart failure (HF) patient and validated against measurements of inter-ventricular interactions in animal experiments. The model was then applied to investigate the effects of LVAD on (1) RV chamber contractility indexed by V 60 derived from its end-systolic PV relationship, and (2) RV diastolic function indexed by V 20 derived from its end-diastolic PV relationship. We also investigated how septal wall thickness and regional contractility affect the impact of LVAD on RV function., Results: The impact of LVAD on RV chamber contractility is small at a pump speed lower than 4k rpm. At a higher pump speed between 4k and 9k rpm, however, RV chamber contractility is reduced (by ~3% at 6k rpm and ~10% at 9k rpm). The reduction of RV chamber contractility is greater with a thinner septal wall or with a lower myocardial contractility at the LV free wall, septum, or RV free wall., Conclusion: RV chamber contractility is reduced at a pump speed higher than 4k rpm, and this reduction is greater with a thinner septal wall or lower regional myocardial contractility. Findings here may have clinical implications in identifying LVAD patients who may suffer from RV failure., (© 2023 International Center for Artificial Organ and Transplantation (ICAOT) and Wiley Periodicals LLC.)

Aims: We assessed the incidence, predictors and clinical correlates of de-novo aortic regurgitation (AR), which physiologically reduces left ventricular assist device (LVAD) effectiveness due to recirculation syndrome, in the MOMENTUM 3 trial portfolio of the fully magnetically levitated HeartMate 3 (HM3) pump using the randomized pivotal trial (PT) and post-trial continued access protocol (CAP)., Methods and Results: De-novo aortic regurgitation incidence at 2 years was analysed in the randomized PT and validated in the first 1000 implanted patients of the CAP. Patients with concomitant/prior aortic valve surgery or without baseline or post-implant echocardiograms were excluded from this analysis. AR severity was assessed qualitatively by site-adjudicated echocardiograms (significant AR was defined as moderate or severe grade on echocardiogram). Of 1028 patients enrolled in the PT, 918 were eligible for inclusion in this analysis (HM3, n = 465; HMII, n = 453). At 2 years of LVAD support, freedom from significant AR was greater in the HM3 (92%) than HMII (82%) (hazard ratio 0.45, 95% confidence interval 0.27-0.75, p < 0.01). Of 907 HM3 patients analysed from the first 1000 implanted CAP patients, the rate of freedom from significant AR was 90%, consistent with the PT (p = 0.3). In the combined HM3 group (n = 1372), multivariable Cox modelling identified increasing age and female sex as significant predictors. Survival free of urgent transplant or AR corrective procedure was similar between HM3 patients with and without significant de-novo AR., Conclusions: The development of moderate or severe grade de-novo AR is reduced with the fully magnetically levitated HM3 LVAD compared to the axial-flow HMII pump. The occurrence of significant de-novo AR with the HM3 pump is not associated with a worse outcome at 2 years of follow-up., (© 2022 European Society of Cardiology.)

Background: Outcomes in patients with smaller body size after HeartMate 3 left ventricular assist device (HM3) implantation are not well characterized. We sought to evaluate outcomes in smaller vs larger body surface area (BSA) patients in the MOMENTUM 3 pivotal trial and its Continued Access Protocol cohort., Methods: The analysis cohort included 1015 HM3 patients divided into 2 groups: BSA ≤1.70 m 2 (small patients, n = 82) and BSA >1.70 m 2 (large patients, n = 933). The composite primary end point was survival at 2 years free of disabling stroke or reoperation to replace or to remove a malfunctioning device. Adverse events were compared between groups., Results: Smaller patients were more frequently women (56.1% vs 17.7%; P < .001) and had lower prevalence of diabetes (28.1% vs 43.9%; P = .005) and hypertension (51.2% vs 71.9%; P < .001), larger median indexed LVEDD (normalized by BSA, 40 vs 33 mm/m 2 ; P < .001), and lower median serum creatinine concentration (1.1 vs 1.3 mg/dL; P < .001). The proportion of patients achieving the composite end point at 2 years was 77% in both groups (adjusted hazard ratio, 1.14; 95% CI, 0.68-1.91; P = .62). Two-year adverse event rates were also similar between groups except for sepsis (6.1% vs 14.9%; P = .029) and cardiac arrhythmias (24.4% vs 35.3%; P = .005), which were higher in the larger patients., Conclusions: Outcomes after HM3 implantation were comparable between small and large patients. Smaller body size should not be used to deny HM3 implantation in patients who are otherwise suitable candidates for durable mechanical circulatory support., (Copyright © 2022 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Purpose: To evaluate the effect of the new heart transplant (HT) allocation system in left ventricular assist device (LVAD) supported patients listed as bridge to transplantation (BTT)., Methods: Adult patients who were listed for HT between October 18, 2016 and October 17, 2019, and were supported with an LVAD, enrolled in the UNOS database were included in this study. Patients were classified in the old or new system if they were listed or transplanted before or after October 18, 2018, respectively., Results: A total of 3261 LVAD patients were listed for transplant. Of these, 2257 were classified in the old and 1004 in the new system. The cumulative incidence of death or removal from the transplant list due to worsening clinical status at 360-days after listing was lower in the new system (4% vs. 7%, P = .011). LVAD Patients listed in the new system had a lower frequency of transplantation within 360-days of listing (52% vs. 61%, P < .001). A total of 1843 LVAD patients were transplanted, 1004 patients in the old system and 839 patients in the new system. The post-transplant survival at 360 days was similar between old and new systems (92.3% vs. 90%, P = .08). However, LVAD patients transplanted in the new system had lower frequency of the combined endpoint, freedom of death or re-transplantation at 360 days (92.2% vs. 89.6%, P = .046)., Conclusion: The new HT allocation system has affected the LVAD-BTT population significantly. On the waitlist, LVAD patients have a decreased cumulative frequency of transplantation and a concomitant decrease in death or delisting due to worsening status. In the new system, LVAD patients have a decreased survival free of re-transplantation at 360 days post-transplant., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Multicenter data on long term survival following LVAD implantation that make use of contemporary definitions of RV failure are limited. Furthermore, traditional survival analyses censor patients who receive a bridge to heart transplant. Here we compare the outcomes of LVAD patients who develop post-operative RV failure accounting for the transitional probability of receiving an interim heart transplantation., Methods: We use a retrospective cohort of LVAD patients sourced from multiple high-volume centers based in the United States. Five- and ten-year survival accounting for transition probabilities of receiving a heart transplant were calculated using a multi-state Aalen Johansen survival model., Results: Of the 897 patients included in the study, 238 (26.5%) developed post-operative RV failure at index hospitalization. At 10 years the probability of death with post-op RV failure was 79.28% vs 61.70% in patients without (HR 2.10; 95% CI 1.72 - 2.57; p = < .001). Though not significant, patients with RV failure were less likely to be bridged to a heart transplant (HR 0.87, p = .4). Once transplanted the risk of death between both patient groups remained equivalent; the probability of death after a heart transplant was 3.97% in those with post-operative RV failure shortly after index LVAD implant, as compared to 14.71% in those without., Conclusions and Relevance: Long-term durable mechanical circulatory support is associated with significantly higher mortality in patients who develop post-operative RV failure. Improving outcomes may necessitate expeditious bridge to heart transplant wherever appropriate, along with critical reassessment of organ allocation policies., (Copyright © 2021 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)

Background: Limited data are available regarding the outcomes of patients supported by extracorporeal membrane oxygenation (ECMO) who undergo durable mechanical circulatory support implantation (dMCS). We analyzed the clinical characteristics, outcomes, and risk factors for mortality in patients who were bridged with ECMO to dMCS., Methods: Adult patients who received dMCS between January 2008 and December 2017 (n=19 824), registered in the Society of Thoracic Surgeons-Interagency Registry for Mechanical Assisted Circulatory Support (STS-INTERMACS) database were included. Baseline characteristics, outcomes, risk factors, and adverse events were compared between ECMO-supported patients (n=933) and INTERMACS profile 1 (IP-1) patients not supported by ECMO (n=2362). A propensity match analysis was performed., Results: ECMO patients had inferior survival at 12 months (66.1%) than non-ECMO patients (75.4%; P <0.0001). The proportion of patients transplanted at 2 years after dMCS was similar between the ECMO (30.8%) and non-ECMO (31.8%) groups ( P =0.49). A multiphase parametric hazard model identified 2 different periods based on risk of death. ECMO patients had a high hazard for death in the first 6 months after implantation (hazard ratio, 2.18 [1.79-2.66]; P <0.001). Multivariable analysis showed that ECMO was an independent risk factor associated with poor outcome during the early phase after dMCS (hazard ratio, 1.69 [1.37-2.09]; P <0.0001) but not during the constant phase. ECMO patients had similar outcomes to non-ECMO patients when a propensity matched cohort was analyzed., Conclusions: ECMO-supported patients before dMCS have lower survival compared with other IP-1 patients. A multivariable analysis showed that ECMO is an independent risk factor of poor outcome after dMCS. However, a propensity matched analysis suggested that when important clinical variables are controlled the outcome of both groups is similar. These data support the implantation of dMCS in carefully selected ECMO patients.

Background: The HeartWare centrifugal-flow ventricular assist device system (HVAD) is a viable option for treatment of advanced heart failure. There is a growing trend toward the use of less invasive techniques in cardiac surgery, and the thoracotomy technique for HVAD implantation may provide benefits not available with conventional approaches., Methods: The LATERAL trial is a multicenter, prospective, non-randomized, single-arm trial that utilized data from 144 patients enrolled in the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) database at 26 centers in the United States and Canada. The primary composite end-point was success at 180 days defined as alive on the originally implanted device and free from disabling stroke (modified Rankin Scale score >3), transplanted or explanted for recovery. The key secondary end-point was mean length of initial hospital stay., Results: The primary end-point was successfully achieved in 88.1% of patients and was significantly greater than the pre-defined performance goal of 77.5% set from historical sternotomy data (p = 0.0012). The key secondary end-point-mean length of initial hospital stay -was 18 days and was significantly shorter than the pre-defined performance goal of 26.1 days obtained from historical sternotomy data (p < 0.0001). The adverse event profile further demonstrated the safety of the thoracotomy approach. The overall patient survival was good, and bleeding requiring reoperation was significantly less frequent than that observed in previous studies using the sternotomy approach., Conclusions: This prospective clinical trial provides validation that implantation of the HVAD system via the thoracotomy approach used in the LATERAL study represents a safe and effective alternative to median sternotomy in selected patients intended for a bridge-to-transplant indication., (Copyright © 2019. Published by Elsevier Inc.)

Aims: The time course of changes in pulmonary artery (PA) pressure due to left ventricular assist devices (LVADs) is not well understood. Here, we describe longitudinal haemodynamic trends during the peri-LVAD implantation period in patients previously implanted with a remote monitoring PA pressure sensor., Methods and Results: We retrospectively studied PA pressure trends in patients implanted with CardioMEMS™ PA pressure sensor between October 2007 and March 2017 who subsequently had an LVAD procedure. Data are presented as mean ± standard deviation, and P-values are calculated using standard t-test with equal variance. Among 436 patients in cohort, 108 (age 58 ± 11 years, 82% male) received an LVAD and 328 (age 60 ± 13 years, 70% male) did not. The mean PA pressure at sensor implant was higher by 29% (P < 0.001) among patients who later received LVAD. Mean PA pressure 6 months prior to LVAD implant was 35.5 ± 8.5 mmHg, increasing to 39.4 ± 9.9 mmHg (P = 0.04) at 4 weeks before LVAD, and then decreasing 27% to 28.8 ± 8.4 mmHg (P < 0.001) at 3 months post-implant and stabilizing at 31.0 ± 9.4 mmHg at 1 year., Conclusions: Patients who later receive LVADs have higher PA pressures at sensor implant and show a further increase leading up to LVAD implantation. There is a significant reduction of PA pressures post-LVAD implantation that persists long term. PA pressure monitoring may aid in the clinical decision making of timing for LVAD implantation and in management of LVAD patients., (© 2018 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of the European Society of Cardiology.)

Purpose: Psychosocial assessment of patients comprises an important element in the selection process of appropriate candidates for left ventricular assist device (LVAD) implantation. We sought to determine the association of the well-validated psychosocial assessment of candidates for transplantation (PACT) scale to clinical outcomes post-LVAD implantation., Materials and Methods: The PACT scale was used retrospectively to reconstruct psychosocial profiles of all patients who underwent a continuous-flow LVAD implantation for all indications at our institution between March 2008 and August 2012 (N = 230). Psychosocial elements including social support, psychological health, lifestyle factors, comprehension of the operation, and follow-up were evaluated. The primary outcome was overall survival, and the secondary outcomes were hospital readmission, pump thrombosis, hemolysis, gastrointestinal (GI) bleeding, and LVAD driveline infections., Results: The mean age of patients was 55.3 years, with 83% being male; 58% (N = 135) were bridge to transplant and 42% (N = 95) were destination therapy. Up to 1-year post-LVAD implant, there were no statistical differences among the 5 PACT candidate groups in terms of survival ( P = .79), hospital readmissions ( P = .55), suspected or confirmed pump thrombosis ( P = .31), hemolysis ( P = .43), GI bleeding ( P = .71), or driveline infections ( P = .06)., Conclusions: In this single-center retrospective review, post hoc reconstruction of psychosocial profiles using the PACT scale and independent assessment of postimplant outcomes, including survival and adverse events, did not show any association. However, given the small number of patients in the low score PACT groups as well as limited duration of follow-up, further studies are required to elucidate the association.

Left ventricular assist device (LVAD) therapy has emerged as an increasingly vital facet of the treatment algorithm for advanced heart failure. Growing experience with LVAD support has led to substantial improvements in outcomes, with 1-year survival rates approaching that of cardiac transplantation. These therapeutic refinements have engendered growing interests in the potential for expanding the clinical indications for LVAD therapy to patients with less advanced heart failure. The primary obstacles to this evolution of care center largely on the prevention and/or management of the adverse events associated with LVAD therapy along with patient preference. Many programs also face the mounting difficulty of balancing quality outcomes with the increased volume of implants. During the recently assembled Users Meeting organized by St. Jude Medical, heart failure clinicians from nearly 50 LVAD implanting centers discussed these and other challenges and controversies impacting the field. The present review summarizes the key insights gleaned from this meeting., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Purpose of Review: The purpose of this review is to describe the current knowledge in prevention and treatment of thrombotic (pump thrombosis and ischemic stroke) and bleeding (gastrointestinal and hemorrhagic stroke) complications in patients supported by continuous-flow left ventricular assist devices (CF-LVAD)., Recent Findings: Left ventricular assist devices (LVADs) are now widely used for the management of end-stage heart failure. Unfortunately, in spite of the indisputable positive impact LVADs have on patients, the frequency and severity of complications are limitations of this therapy. Stroke, pump thrombosis, and gastrointestinal bleeding are among the most serious and frequent complications in these patients. The balance between hemorrhagic and thrombotic complications in patients supported with CF-LVAD is difficult as most patients do not necessarily fit a "bleeder" or a "clotter" profile but rather move from one side to the other of the thrombotic/bleeding spectrum. Further research is necessary to better understand the risk factors and mechanisms involved in the development of these complications.

Objectives: The authors sought to provide the pre-specified primary endpoint of the ROADMAP (Risk Assessment and Comparative Effectiveness of Left Ventricular Assist Device and Medical Management in Ambulatory Heart Failure Patients) trial at 2 years., Background: The ROADMAP trial was a prospective nonrandomized observational study of 200 patients (97 with a left ventricular assist device [LVAD], 103 on optimal medical management [OMM]) that showed that survival with improved functional status at 1 year was better with LVADs compared with OMM in a patient population of ambulatory New York Heart Association functional class IIIb/IV patients., Methods: The primary composite endpoint was survival on original therapy with improvement in 6-min walk distance ≥75 m., Results: Patients receiving LVAD versus OMM had lower baseline health-related quality of life, reduced Seattle Heart Failure Model 1-year survival (78% vs. 84%; p = 0.012), and were predominantly INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support) profile 4 (65% vs. 34%; p < 0.001) versus profiles 5 to 7. More LVAD patients met the primary endpoint at 2 years: 30% LVAD versus 12% OMM (odds ratio: 3.2 [95% confidence interval: 1.3 to 7.7]; p = 0.012). Survival as treated on original therapy at 2 years was greater for LVAD versus OMM (70 ± 5% vs. 41 ± 5%; p < 0.001), but there was no difference in intent-to-treat survival (70 ± 5% vs. 63 ± 5%; p = 0.307). In the OMM arm, 23 of 103 (22%) received delayed LVADs (18 within 12 months; 5 from 12 to 24 months). LVAD adverse events declined after year 1 for bleeding (primarily gastrointestinal) and arrhythmias., Conclusions: Survival on original therapy with improvement in 6-min walk distance was superior with LVAD compared with OMM at 2 years. Reduction in key adverse events beyond 1 year was observed in the LVAD group. The ROADMAP trial provides risk-benefit information to guide patient- and physician-shared decision making for elective LVAD therapy as a treatment for heart failure. (Risk Assessment and Comparative Effectiveness of Left Ventricular Assist Device and Medical Management in Ambulatory Heart Failure Patients [ROADMAP]; NCT01452802)., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Early right-sided heart failure (RHF) after left ventricular assist device (LVAD) implantation is associated with increased mortality, but little is known about patients who develop late RHF (LRHF). We evaluated the incidence, risk factors, and clinical impact of LRHF in patients supported by axial-flow LVADs., Methods: Data were analyzed from 537 patients enrolled in the HeartMate II (HM II; Thoratec/St. Jude) destination therapy clinical trial. LRHF was defined as the development of clinical RHF accompanied by the need for inotropic support occurring more than 30 days after discharge from the index LVAD implant hospitalization. Clinical variables, quality of life, rehospitalizations, and survival were compared between patients with and without LRHF., Results: LRHF developed in 41 patients (8%), with a median time to LRHF of 480 days. A higher preoperative blood urea nitrogen and increased central venous pressure-to-pulmonary capillary wedge pressure ratio were independent predictors of LRHF. The Michigan and HMII RHF risk scores were both associated with an increased likelihood of LRHF (p < 0.05). Patients with LRHF had worse quality of life according to the Kansas City Cardiomyopathy Questionnaire (61 ± 26 vs 70 ± 21; p < 0.05), poorer functional capacity by 6-minute walk distance (275 ± 189 m vs 312 ± 216 m; p < 0.05), and more rehospitalizations (6 vs 3; p < 0.001). LRHF was associated with decreased survival (p < 0.001)., Conclusions: LRHF is an important complication in patients with LVADs and is associated with worse quality of life, reduced functional capacity, more frequent hospitalizations, and worse survival compared with those without LRHF., (Copyright © 2016 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)

There is insufficient data on patients with small body size to determine if this should be considered a risk factor for continuous-flow left ventricular assist device (CF-LVAD) support. We sought to evaluate survival outcomes, adverse events, and functional status of CF-LVAD patients with body surface area (BSA) <1.5 m in a large national registry. Adults with BSA < 1.5 m (n = 128) implanted with a HeartMate II (HMII)-LVAD from the Interagency Registry for Mechanically Assisted Circulatory Support registry from April 2008 to December 2012 formed this cohort. Outcomes were compared with HMII bridge to transplant (BTT) and destination therapy (DT) post approval studies. The majority of patients were female (n = 106, 83%). A total of 64% (n = 82) were implanted for BTT and 36% (n = 46) for DT. The median BSA (range) was 1.44 (1.19-1.49) and 1.45 (1.25-1.49) m for BTT and DT, respectively. Overall survival 1 year post implant was 81% ± 5% for BTT and 84% ± 6% for DT. The most common adverse events for BTT and DT patients were bleeding (0.91, 0.88 events/patient year) and driveline infection (16%, 0.28 events/patient year). Six months post implantation, 87% of BTT and 77% of DT patients were New York Heart Association functional class I or II. Post implant survival, functional status improvement, and adverse event profile for adult BTT and DT HMII patients with BSA < 1.5 m are favorable and comparable with outcomes published in the overall patient population.

Background: Allogeneic mesenchymal precursor cells (MPCs) injected during left ventricular assist device (LVAD) implantation may contribute to myocardial recovery. This trial explores the safety and efficacy of this strategy., Methods and Results: In this multicenter, double-blind, sham-procedure controlled trial, 30 patients were randomized (2:1) to intramyocardial injection of 25 million MPCs or medium during LVAD implantation. The primary safety end point was incidence of infectious myocarditis, myocardial rupture, neoplasm, hypersensitivity reaction, and immune sensitization (90 days after randomization). Key efficacy end points were functional status and ventricular function while temporarily weaned from LVAD support (90 days after randomization). Patients were followed up until transplant or 12 months after randomization, whichever came first. Mean age was 57.4 (±13.6) years, mean left ventricular ejection fraction was 18.1%, and 66.7% were destination therapy LVADs. No safety events were observed. Successful temporary LVAD weaning was achieved in 50% of MPC and 20% of control patients at 90 days (P=0.24); the posterior probability that MPCs increased the likelihood of successful weaning was 93%. At 90 days, 3 deaths (30%) occurred in control patients, and none occurred in MPC patients. Mean left ventricular ejection fraction after successful wean was 24.0% (MPC=10) and 22.5% (control=2; P=0.56). At 12 months, 30% of MPC patients and 40% of control patients were successfully temporarily weaned from LVAD support (P=0.69), and 6 deaths (30%) occurred in MPC patients. Donor-specific HLA sensitization developed in 2 MPC and 3 control patients and resolved by 12 months., Conclusions: In this preliminary trial, administration of MPCs appeared to be safe, and there was a potential signal of efficacy. Future studies will evaluate the potential for higher or additional doses to enhance the ability to wean LVAD recipients off support., Clinical Trial Registration Url: http://www.clinicaltrials.gov. Unique identifier: NCT01442129., (© 2014 American Heart Association, Inc.)

With implantable cardiac assist devices increasingly proving their effectiveness as therapeutic options for end-stage heart failure, it is important for clinicians to understand the unique physiology of device-assisted circulation. Preload sensitivity as it relates to cardiac assist devices is derived from the Frank-Starling relationship between human ventricular filling pressures and ventricular stroke volume. In this review, we stratify the preload sensitivity of 17 implantable cardiac assist devices relative to the native heart and discuss the effect of preload sensitivity on left ventricular volume unloading, levels of cardiac support, and the future development of continuous-flow total artificial heart technology., (Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

The recent success of continuous-flow circulatory support devices has led to the growing acceptance of these devices as a viable therapeutic option for end-stage heart failure patients who are not responsive to current pharmacologic and electrophysiologic therapies. This article defines and clarifies the major classification of these pumps as axial or centrifugal continuous-flow devices by discussing the difference in their inherent mechanics and describing how these features translate clinically to pump selection and patient management issues. Axial vs centrifugal pump and bearing design, theory of operation, hydrodynamic performance, and current vs flow relationships are discussed. A review of axial vs centrifugal physiology, pre-load and after-load sensitivity, flow pulsatility, and issues related to automatic physiologic control and suction prevention algorithms is offered. Reliability and biocompatibility of the two types of pumps are reviewed from the perspectives of mechanical wear, implant life, hemolysis, and pump deposition. Finally, a glimpse into the future of continuous-flow technologies is presented., (Copyright © 2013 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)

The development of ventricular assist devices (VADs) over the past 5 decades as therapy for advanced heart failure (HF) has been extraordinary. Since the original VAD design by Michael DeBakey in the early 1960s, numerous devices for mechanical circulatory support have been engineered, assessed in preclinical studies, applied to human patients in large multicenter clinical trials, and now, select devices are Food and Drug Administration-approved therapy for advanced HF patients. This review highlights select examples of durable VADs from the engineering aspect of design and conception to experimental studies and clinical application underscoring the remarkable progression of such technology to now becoming the standard of care for many advanced HF patients., (Copyright © 2013 S. Karger AG, Basel.)

Although the need for right ventricular assist device (RVAD) support for right ventricular failure after the implantation of a continuous-flow left ventricular assist device has decreased, right ventricular failure still occurs in as many as 44% of patients after continuous-flow left ventricular assist device insertion. Cleveland Clinic's DexAide continuous-flow RVAD was implanted in 34 calves during the course of its development. This review discusses lessons learned in the design and development of an implantable continuous-flow RVAD that are drawn from the results of these in vivo studies, our clinical experience with RVAD support, and a review of previously published reports on clinical RVAD use., (Copyright © 2012 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

The discrepancy between the limited availability of donor hearts and the ever-increasing number of patients with heart failure has led to the increasing use of left ventricular assist devices (LVAD) as a bridge to transplant. One of the main complications inherent following institution of LVAD therapy is right ventricular (RV) failure, manifested by the need for inotropic and/or nitric oxide support >14 days after LVAD implant and/or the need for right-sided mechanical circulatory support. RV failure is a major contributor of significant morbidity and mortality after LVAD placement. The complex pathophysiology of RV failure, which could potentially be related to RV myocardial dysfunction, interventricular dependence, and RV afterload, has led to inconsistencies in predicting risk factors for RV dysfunction. Several strategies have evolved over the years of experience with mechanical circulatory support that have aimed to avoid as well as reduce the incidence of RV failure. It is imperative that patients who definitely need biventricular support are identified. Despite the numerous risk factors identified in many studies as well as the development of risk factor profile scores, this continues to be a challenging problem. However, the lower incidence of RV failure following LVAD in the current era is encouraging, suggesting a favorable relationship between RV unloading and function, and continuous-flow physiology.

Background: Continuous-flow devices have become the standard of care for mechanical circulatory support for end-stage heart failure patients because of improved survival and durability. The effects of these devices, such as the HeartMate II (HMII) left ventricular assist device (LVAD), on right ventricular (RV) function have not been evaluated in detail. This study evaluated the incidence of RV failure, alterations in RV function, severity of tricuspid regurgitation (TR), and cardiac hemodynamics after HMII implantation., Methods: Echocardiograms (n = 22) and right heart catheterizations (n = 40) were performed before and after 4 to 6 months of HMII support in 40 bridge-to-transplant patients. Right heart failure was defined as the requirement for inotropes and/or nitric oxide requirement after LVAD implantation for >14 days or the need for right-sided mechanical circulatory support., Results: Overall, RV failure after HMII implantation occurred in 2 of 40 patients (5%). Significant improvements occurred in cardiac index, with reductions in right atrial pressure, RV stroke work index, tricuspid annular motion, mean pulmonary artery pressure, and pulmonary vascular resistance after HMII support. There was a trend towards reduction in TR after LVAD support (p = 0.075)., Conclusions: The incidence of RV failure after support with continuous-flow devices such as the HMII is low. The favorable effects of the HMII on cardiac hemodynamics result in improved RV function, improved right- and left-sided hemodynamic profiles, and a reduction in TR severity. These findings may have important implications for LVAD patients needing longer-term support.

The clinical success of left ventricular assist devices (LVADs) has been tempered by significant hemorrhagic and thromboembolic complications. In the case of LVADs, where the biomaterial is in direct contact with the blood circulation, significant changes in systemic immunologic and thrombostatic functions have been well documented. Although further investigation is warranted, significant advances have been made in both cellular biology and LVAD technology to better understand the delicate balance between the procoagulant milieu predisposing to thrombosis and the risks of both surgical and non-surgical bleeding.

Aims: A novel combination therapy consisting of a left ventricular assist device (LVAD) combined with pharmacologic therapy including the selective beta(2)-agonist, clenbuterol, has shown promise in restoring ventricular function in patients with heart failure. The aim of this study was to identify common genes and signalling pathways whose expression was associated with reversal of heart failure and restoration of ventricular function., Methods and Results: Microarray analysis was performed on six paired human heart samples harvested at the time of LVAD implant and at the time of LVAD explant for recovery of ventricular function (post). Follow-up data shows that the improvements in ventricular function have been maintained for an average of 3.8 years post-explant. Analysis of the gene expression data revealed: (i) a significant association of integrin pathway signalling with recovery and (ii) the identification of several novel targets including, EPAC2, in the well-described cAMP pathway whose expression was down-regulated with recovery, and was associated with improvements in cardiac contractility, metabolism, and function., Conclusion: This data set represents the first description of signalling pathways associated with the functional recovery of end-stage human heart failure and the identification of new targets in the human heart that are modified by this combination therapy.