Continuous-flow Left Ventricular Assist Device Research Articles

Explainable Machine Learning Analysis of Right Heart Failure After Left Ventricular Assist Device Implantation.

Right heart failure (RHF) remains a common and serious complication after durable left ventricular assist device (LVAD) implantation. We used explainable machine learning (ML) methods to derive novel insights into preimplant patient factors associated with RHF. Continuous-flow LVAD implantations from 2008 to 2017 in the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) were included. A total of 186 preimplant patient factors were analyzed and the primary outcome was 30 days of severe RHF. A boosted decision tree ML algorithm and an explainable ML method were applied to identify the most important factors associated with RHF, nonlinear relationships and interactions, and risk inflection points. Out of 19,595 patients, 19.1% developed severe RHF at 30 days. Thirty top predictors of RHF were identified with the top five being INTERMACS profile, Model for End-stage Liver Disease score, the number of inotropic infusions, hemoglobin, and race. Many top factors exhibited nonlinear relationships with key risk inflection points such as INTERMACS profile between 2 and 3, right atrial pressure of 15 mmHg, pulmonary artery pressure index of 3, and prealbumin of 23 mg/dl. Finally, the most important variable interactions involved INTERMACS profile and the number of inotropes. These insights could help formulate patient optimization strategies prior to LVAD implantation.

A computational study of aortic insufficiency in patients supported with continuous flow left ventricular assist devices: Is it time for a paradigm shift in management?

De novo aortic insufficiency (AI) following continuous flow left ventricular assist device (CF-LVAD) implantation is a common complication. Traditional early management utilizes speed augmentation to overcome the regurgitant flow in an attempt to augment net forward flow, but this strategy increases the aortic transvalvular gradient which predisposes the patient to progressive aortic valve pathology and may have deleterious effects on aortic shear stress and right ventricular (RV) function. We employed a closed-loop lumped-parameter mathematical model of the cardiovascular system including the four cardiac chambers with corresponding valves, pulmonary and systemic circulations, and the LVAD. The model is used to generate boundary conditions which are prescribed in blood flow simulations performed in a three-dimensional (3D) model of the ascending aorta, aortic arch, and thoracic descending aorta. Using the models, impact of various patient management strategies, including speed augmentation and pharmacological treatment on systemic and pulmonary (PA) vasculature, were investigated for four typical phenotypes of LVAD patients with varying degrees of RV to PA coupling and AI severity. The introduction of mild/moderate or severe AI to the coupled RV and pulmonary artery at a speed of 5,500 RPM led to a reduction in net flow from 5.4 L/min (no AI) to 4.5 L/min (mild/moderate) to 2.1 L/min (severe). RV coupling ratio (Ees/Ea) decreased from 1.01 (no AI) to 0.96 (mild/moderate) to 0.76 (severe). Increasing LVAD speed to 6,400 RPM in the severe AI and coupled scenario, led to a 42% increase in net flow and a 16% increase in regurgitant flow (RF) with a nominal decrease of 1.6% in RV myocardial oxygen consumption (MVO2). Blood pressure control with the coupled RV with severe AI at 5,500 RPM led to an 81% increase in net flow with a 15% reduction of RF and an 8% reduction in RV MVO2. With an uncoupled RV, the introduction of mild/moderate or severe AI at a speed of 5,500 RPM led to a reduction in net flow from 5.0 L/min (no AI) to 4.0 L/min (mild/moderate) to 1.8 L/min (severe). Increasing the speed to 6,400 RPM with severe AI and an uncoupled RV increased net flow by 45%, RF by 15% and reduced RV MVO2 by 1.1%. For the uncoupled RV with severe AI, blood pressure control alone led to a 22% increase in net flow, 4.2% reduction in RF, and 3.9% reduction in RV MVO2; pulmonary vasodilation alone led to a 18% increase in net flow, 7% reduction in RF, and 26% reduction in RV MVO2; whereas, combined BP control and pulmonary vasodilation led to a 113% increase in net flow, 20% reduction in RF and 31% reduction in RV MVO2. Compared to speed augmentation, blood pressure control consistently resulted in a reduction in WSS throughout the proximal regions of the arterial system. Speed augmentation to overcome AI in patients supported by CF-LVAD appears to augment flow but also increases RF and WSS in the aorta, and reduces RV MVO2. Aggressive blood pressure control and pulmonary vasodilation, particularly in those patients with an uncoupled RV can improve net flow with more advantageous effects on the RV and AI RF.

Impact of Pre-Operative Right Ventricular Response to Hemodynamic Optimization on Outcomes in Patients with LVADs.

Background: Right ventricular failure (RVF) continues to affect patients supported with durable left ventricular assist devices (LVAD) and results in increased morbidity and mortality. Information regarding the impact of right ventricular response to pre-operative optimization on outcomes is scarce. Methods: Single-center retrospective analysis of consecutive patients who underwent first continuous flow LVAD implantation between 2006 and 2020. Patients with bi-ventricular support before LVAD or without hemodynamic data were excluded. Invasive hemodynamics at baseline and after pre-operative medical and/or temporary circulatory support were recorded. Patients were grouped in the following categories: A: No Hemodynamic RV dysfunction (RVD) at baseline; B: RVD with achievement of RV hemodynamic optimization goals; C: RVD without achievement of RV optimization goals. The main outcomes were right ventricular failure defined as inotropes >14 days after implantation, or postoperative right ventricular mechanical support, and all-cause mortality. Results: Overall, 128 patients were included in the study. The mean age was 58 ± 12.5 years, 74.2% were males and, 68.7% had non-ischemic cardiomyopathy. Hemodynamic RVD was present in 70 (54.7%) of the patients at baseline. RV hemodynamic goals were achieved in 46 (79.31%) patients with RVD and in all the patients without RVD at baseline. Failure to achieve hemodynamic optimization goals was associated with a significantly higher risk of RVF after LVAD implantation (adjusted OR 4.37, 95% CI 1.14–16.76, p = 0.031) compared with no RVD at baseline and increased 1-year mortality compared with no RVD (adjusted HR 4.1, 95% CI 1.24–13.2, p = 0.02) and optimized RVD (adjusted HR 6.4, 95% CI 1.6–25.2, p = 0.008).Conclusion: Among patients with RVD, the inability to achieve hemodynamic optimization goals was associated with higher rates of RV failure and increased 1-year all-cause mortality post LVAD implantation.

Intravenous Iron Repletion in Patients With Continuous-Flow Left Ventricular Assist Devices.

Intravenous Iron Repletion in Patients With Continuous-Flow Left Ventricular Assist Devices.

Preliminary Experience of Extracorporeal Cytokine Hemoadsorption during Left Ventricular Assist Device Implantation in Cardiogenic Shock Patients.

Systemic inflammation due to cardiogenic shock is associated with vasoplegia leading to organ hypoperfusion, right heart failure, and poor clinical outcome. Extracorporeal cytokine hemoadsorption emerged to attenuate excessive levels of inflammatory cytokines, potentially improving patient outcomes. Nevertheless, its prognostic impact during high-risk left ventricular assist device (LVAD) implantation remains unknown. In total, 40 consecutive patients with advanced heart failure underwent continuous-flow LVAD implantation at our institution between 2018 and 2020. Out of 25 high-risk patients in cardiogenic shock (Interagency Registry for Mechanically Assisted Circulatory Support profile 1 and 2), 9 patients (CytoSorb group) underwent LVAD implantation with and 16 patients (control group) without simultaneous cytokine hemoadsorption during cardiopulmonary bypass. Besides preoperative patient characteristics, postoperative lactate clearance, vasopressor administration and mean arterial pressure, perioperative complication, and 30-day mortality rates were retrospectively analyzed. Apart from an increased rate of reoperations within the CytoSorb group, baseline characteristics including the severity of ventricular dysfunction and consecutive signs of end-organ failure were similar in both groups. Preoperative short-term mechanical circulatory support bridging was comparable (66.7 vs. 75%; p = 0.66) prior to LVAD implantation. Procedural characteristics including intraoperative volume management and postoperative vasopressor administration were similar in both groups. There was no difference regarding postoperative lactate clearance, although postoperative mean arterial pressure was significantly higher in the control group (71.3 vs. 57.4 mm Hg; p < 0.01). Furthermore, the 30-day mortality rate was significantly higher in the CytoSorb group (33.3 vs. 0.0%; p = 0.01). Extracorporeal cytokine hemoadsorption during high-risk LVAD implantation was not associated with a decrease of postoperative vasopressor support, improved hemodynamics, or an accelerated lactate clearance.

Transcatheter Aortic Valve Replacement and Surgical Aortic Valve Replacement Outcomes in Left Ventricular Assist Device Patients with Aortic Insufficiency.

Background: Worsening aortic insufficiency (AI) is a known sequela of prolonged continuous-flow left ventricular assist device (LVAD) support with a significant impact on patient outcomes. While medical treatment may relieve symptoms, it is unlikely to halt progression. Surgical aortic valve replacement (SAVR) and transcatheter aortic valve replacement (TAVR) are among non-medical interventions available to address post-LVAD AI. Limited data are available on outcomes with either SAVR or TAVR for the management of post-LVAD AI. Methods: The National Inpatient Sample data collected for hospital admissions between the years 2015 and 2018 for patients with pre-existing continuous-flow LVAD undergoing TAVR or SAVR for AI were queried. The primary outcome of interest was a composite of in-hospital mortality, stroke, transient ischaemic attack, MI, pacemaker implantation, need for open aortic valve surgery, vascular complications and cardiac tamponade. Results: Patients undergoing TAVR were more likely to receive their procedure during an elective admission (57.1 versus 30%, p=0.002), and a significantly higher prevalence of comorbidities, as assessed by the Elixhauser Comorbidity Index, was observed in the SAVR group (29 versus 18; p=0.0001). We observed a significantly higher prevalence of the primary composite outcome in patients undergoing SAVR (30%) compared with TAVR (14.3%; p=0.001). Upon multivariable analysis adjusting for the type of admission and Elixhauser Comorbidity Index, TAVR was associated with significantly lower odds of the composite outcome (odds ratio 0.243; 95% CI [0.06-0.97]; p=0.045). Conclusion: In this nationally representative cohort of LVAD patients with post-implant AI, it was observed that TAVR was associated with a lower risk of adverse short-term outcomes compared with SAVR.

Continuous-flow left ventricular assist device treatment for arrhythmogenic right ventricular cardiomyopathy complicated by advanced biventricular failure - University of Tokyo experiences.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiomyocyte disease characterized by intractable ventricular arrhythmia in the majority of affected patients. Some of these patients also manifest right ventricular dysfunction and heart failure symptoms. Fatal ventricular arrhythmia has been the primary cause of death in ARVC patients. However, increased early recognition of ARVC and improvement in arrhythmic risk stratification and treatment have dramatically improved survival. A small proportion of the patients are further complicated by left ventricular impairment at the late phase in addition to right heart failure, for whom only heart transplantation is the last resort. Because of the relative rarity of ARVC with biventricular failure, no consensus or guideline has been reported on how to effectively support these patients with a mechanical circulatory device. Herein, four ARVC patients with biventricular failure were presented who were successfully bridged to heart transplantation after long-term support by isolated continuous-flow LVAD.

Characteristics and outcomes of left ventricular assist device recipients transplanted before and after the new donor heart allocation system

Abstract Background Concerns about the impact of the new donor heart allocation system on post-transplant outcomes have emerged after its implementation. We sought to evaluate the characteristics and outcomes of left ventricular assist device (LVAD) recipients transplanted before and after the implantation of the new policy on October 18, 2018. Methods Data on bridge to transplantation adult LVAD patients January 2015 and October 2021, with durable LVAD as a (BTT), was queried from the United Network of Organ Sharing (UNOS) registry. The main outcomes were 30-day all-cause mortality, 30-day fatal graft failure, 1-year all-cause mortality, treated acute rejection at one year and renal replacement therapy (RRT) for acute renal failure. Results In our study, 7096 patients met the inclusion criteria including 2,435 in the new allocation system. The transplanted patients in the new allocation system era had older donor age, longer ischemic time and higher proportion of newer generation LVADs. Adjusted 30-day all-cause mortality was significantly lower for LVAD recipients in the new allocation system era (sub-hazard ratio [SHR] 0.36, 95% Confidence intervals [CI] 0.27–0.48, p&amp;lt;0.001) without differences in the risk of fatal graft failure and one-year mortality. Significantly lower adjusted 30-day mortality with HVAD and HM3 devices than HM2 in the new allocation system era was found, without differences in one-year mortality. Acute allograft rejection requiring treatment was significantly lower (Odds Ratio 0.78, 95% CI 0.65–0.94, p=0.01) whereas a trend towards higher risk of renal failure requiring RRT was identified. Conclusions Despite changing donor characteristics and longer ischemic times, post-transplant outcomes in LVAD recipients have not worsened with the implementation of the new allocation system and this finding is related to the use of newer generation continuous flow LVADs. Funding Acknowledgement Type of funding sources: None.

Left ventricular assist device implantation via lateral thoracotomy: A systematic review and meta-analysis.

Left ventricular assist device (LVAD) implantation via lateral thoracotomy can offer similar effectiveness to conventional approaches with less perioperative adverse events. We performed a systematic review and meta-analysis to determine the potential benefits of lateral thoracotomy (LT) for LVAD implantation compared to median sternotomy. We searched MEDLINE and Embase databases for studies comparing continuous-flow LVAD implantation using LT with conventional sternotomy. Main outcomes were perioperative mortality and complications. Twenty-five observational studies enrolling 3072 patients were included with a median follow-up of 10 months. Perioperative mortality (30 day or in-hospital) was 7% (LT) and 14% (sternotomy); however, mortality differences were no longer statistically significant in matched/adjusted studies (RR:0.86; 95%CI:0.52-1.44; p=0.58). LT was associated with decreased need for blood product transfusions (mean difference[MD]: -4.7; 95%CI: -7.2 to -2.3 units; p < 0.001), reoperation for bleeding (RR:0.34; 95%CI:0.22-0.54; p < 0.001), postoperative RVAD implantation (RR:0.53; 95%CI:0.36-0.77; p < 0.001), days requiring inotropes (MD: -1.1; 95%CI: -2.1 to -0.03 inotrope days; p=0.04), ICU (MD: -3.3; 95%CI: -6.0 to -0.7 ICU days; p=0.01), and hospital length of stay (MD: -5.1; 95%CI: -10.1 to -0.1 hospital days; p=0.04) in matched/adjusted studies. Overall mortality during follow-up was significantly lower for LT in unmatched/unadjusted studies but not statistically significantly lower in matched/adjusted studies (Hazard Ratio:0.82; 95%CI:0.59-1.14; p=0.24). LVAD implantation via LT was associated with significantly decreased need for blood products, reoperation for bleeding, and postoperative RVAD implantation. Furthermore, days on inotropic support were also lower, likely contributing to the shorter length of stay. These findings support greater use of a LT approach for carefully selected patients.

Baseline QRS duration associates with cardiac recovery in patients with continuous-flow left ventricular assist device implantation

ObjectiveIn chronic heart failure (HF) patients supported with continuous-flow left ventricular assist device (CF-LVAD), we aimed to assess the clinical association of pre-LVAD QRS duration (QRSd) with post-LVAD cardiac recovery, and its correlation with pre- to post-LVAD change in left ventricular ejection fraction (LVEF) and left ventricular end-diastolic diameter (LVEDD). MethodsChronic HF patients (n = 402) undergoing CF-LVAD implantation were prospectively enrolled, at one of the centers comprising the U.T.A.H. (Utah Transplant Affiliated Hospitals) consortium. After excluding patients with acute HF etiologies, hypertrophic or infiltrative cardiomyopathy, and/or inadequate post-LVAD follow up (<3 months), 315 patients were included in the study. Cardiac recovery was defined as LVEF ≥ 40 % and LVEDD < 6 cm within 12 months post-LVAD implantation. Patients fulfilling this condition were termed as responders (R) and results were compared with non-responders (NR). ResultsThirty-five patients (11 %) achieved ‘R’ criteria, and exhibited a 15 % shorter QRSd compared to ‘NR’ (123 ± 37 ms vs 145 ± 36 ms; p < 0.001). A univariate analysis identified association of baseline QRSd with post-LVAD cardiac recovery (OR: 0.986, 95 % CI: 0.976–0.996, p < 0.001). In a multivariate logistic regression model, after adjusting for duration of HF (OR: 0.990, 95 % CI: 0.983–0.997, p = 0.006) and gender (OR: 0.388, 95 % CI: 0.160–0.943, p = 0.037), pre-LVAD QRSd exhibited a significant association with post-LVAD cardiac structural and functional improvement (OR: 0.987, 95 % CI: 0.977–0.998, p = 0.027) and the predictive model showed a c-statistic of 0.73 with p < 0.001. The correlations for baseline QRSd with pre- to post-LVAD change in LVEF and LVEDD were also investigated in ‘R’ and ‘NR’ groups. ConclusionChronic advanced HF patients with a shorter baseline QRSd exhibit an increased potential for cardiac recovery after LVAD support.

Safety and Efficacy of Early Post-Operative Intravenous Iron Replacement In Patients With HeartMate III Left Ventricular Assist Device

Background: While guidelines suggest intravenous (IV) iron to improve functional status and quality of life (QoL) in patients with NYHA class II-III heart failure (HF), continuous flow left ventricular assist device (CF-LVAD) recipients were not included in early IV iron studies. Our study compared outcomes between patients who did and did not receive IV iron during the index admission following Abbott HeartMate III™ (HM 3) CF-LVAD placement. Methods: Thirty-three adult patients with a HM3 placed at our institution who received early post-operative IV iron (n = 20) or no IV iron replacement (n = 13) were compared. The co-primary outcomes were mean change in quality of life (by the Minnesota Living with Heart Failure Questionnaire [MLHFQ]) and 6-minute walk distance (6MWD) from baseline to first >90 day clinic follow-up. Results: At first clinic follow-up there was no significant difference between the IV iron and no-IV iron groups in MLHFQ (−27 ± 38 vs −21 ± 41, P = .8822) or 6MWD (360 ± 740 vs 786 ± 722, P = .208). Conclusion: Patients receiving IV iron during index admission following HM3 implantation did not experience an improvement in quality of life or functional capacity when compared to those who did not receive IV iron.

Cardiac output monitoring with pulmonary versus trans-cardiopulmonary thermodilution in left ventricular assist devices: Interchangeable methods?

Cardiac output (CO) measurement is mandatory in patients with left ventricular assist devices (LVADs). Thermodilution with pulmonary artery catheter (PAC) remains the clinical gold standard to measure CO in these patients, however it is associated with several complications. Therefore, the agreement between PAC and new, minimally invasive monitoring methods in LVAD needs to be further investigated. The aim of this study was to assess the accuracy and reliability of transpulmonary thermodilution with a PiCCO2 monitor compared with pulmonary artery thermodilution with PAC in a LVAD. Continuous-flow LVADs were implanted in six mini-pigs to assist the left ventricle. We studied two methods of measuring CO—intermittent transpulmonary thermodilution (COTPTD) by PiCCO2 and intermittent pulmonary artery thermodilution by CAP, standard technique (COPTD)—obtained in four consecutive moments of the study: before starting the LVAD (basal moment), and with the LVAD started in normovolemia, hypervolemia (fluid overloading) and hypovolemia (shock hemorrhage). A total of 72 paired measurements were analysed. At the basal moment, COTPTD and COPTD were closely correlated (r 2 = 0.89), with a mean bias of −0.085 ± 0.245 L/min and percentage error of 16%. After 15 min of partial support LVAD, COTPTD and COPTD were closely correlated (r 2 = 0.79), with a mean bias of −0.040 ± 0.417 L/min and percentage error of 26%. After inducing hypervolemia, COTPTD and COPTD were closely correlated (r 2 = 0.78), with a mean bias of −0.093 ± 0.339 L/min and percentage error of 13%. After inducing hypovolemia, COTPTD and COPTD were closely correlated (r 2 = 0.76), with a mean bias of −0.045 ± 0.281 L/min and percentage error of 28%. This study demonstrates a good agreement between transpulmonary thermodilution by PiCCO monitor and pulmonary thermodilution by PAC in the intermittent measurement of CO in a porcine model with a continuous-flow LVAD.

Long-term continuous flow ventricular assist in children and adult congenital patients (HeartWare and HeartMate): Current status in France and feedback

The ACHD patient population has the highest rate of death on the transplant waiting list. Compared to optimal medical therapy, continuous flow LVADs (HeartMate and HeartWare) improve survival, quality of life, allow patients to return home. Among them, the HeartMate 3 (HM3) device has the fewest reported adverse events, and the only one available since 2021. HM3 use is associated with low mortality and few adverse events. Foreign literature reports implantations in children as small as 19 kg, as well as ACHD patients with complex heart disease. Current data on the efficacy and safety of implantation in these patients are favorable. No cases have been reported in France to date. To determine the current state of practice in France regarding long-term continuous left-sided single ventricular assist in children and adult congenital patients. To present the results of two successful French implantations. Between June and July 2022, the different pediatric and adult congenital cardiac surgery centers in France and the manufacturers Abbott (HeartMate) and Medtronic (HeartWare) were contacted. A questionnaire will be sent to surgical centers to understand the low use of this type of assistance in France in 2022. The cases of two patients implanted at the Georges Pompidou European Hospital between 2020 and 2022 will be reported: the case of a 15-year-old patient with dilated cardiomyopathy in the context of Duchenne muscular dystrophy, and the case of a 36-year-old patient with Fontan circulation and systolic dysfunction of his single ventricle. The description will include quality of life indexes, collected by means of a questionnaire under stable conditions. The aim of this study is to identify the reasons for the low use of long-term continuous left single ventricular assistance in the population concerned. The aim will be to promote this practice in this population. The sharing of experiences is essential in such a specialized field. We will propose lines of thought to promote long-term assistance in non-experienced centers.

Non-intrusive PODI-ROM for patient-specific aortic blood flow in presence of a LVAD device.

Left ventricular assist devices (LVADs) are used to provide haemodynamic support to patients with critical cardiac failure. Severe complications can occur because of the modifications of the blood flow in the aortic region. In this work, the effect of a continuous flow LVAD device on the aortic flow is investigated by means of a non-intrusive reduced order model (ROM) built using the proper orthogonal decomposition with interpolation (PODI) method based on radial basis functions (RBF). The full order model (FOM) is represented by the incompressible Navier-Stokes equationsdiscretized by using a Finite Volume (FV) technique, coupled with three-element Windkessel models to enforce outlet boundary conditions in a multi-scale approach. A patient-specific framework is proposed: a personalized geometry reconstructed from Computed Tomography (CT) images is used and the individualization of the coefficients of the three-element Windkessel models is based on experimental data provided by the Right Heart Catheterization (RHC) and Echocardiography (ECHO) tests. At FOM level, we also consider the pre-surgery configuration in order to further validate the predictive capabilities of the model in several contexts. The ROM has been tested by considering a parametric setting with respect to the LVAD flow, which is a crucial parameter of the problem. We consider a parameter range that covers typical clinical values. The accuracy of the ROM is assessed against results obtained with the FOM both for primal, velocity and pressure, and derived quantities, wall shear stress (WSS). Finally, we briefly discuss the efficiency of our ROM approach.

Impact of digoxin utilization on clinical outcomes following left ventricular assist device implantation.

We aimed to assess the impact of digoxin use following left ventricular assist device (LVAD) implantation on clinical outcomes. Patients implanted with continuous flow LVADs at a single academic medical center and survived to initial hospital discharge were included in the analysis (n = 346). Clinical events were captured at a maximum of 2 years of follow up. Digoxin use was defined as 30-day continuous use post-LVAD. Negative binomial regression and Kaplan-Meier method were used to assess the association between digoxin use and clinical outcomes. Mean age of the cohort was 56 years (±13) and 23% (79/346) were female sex. Digoxin was used in 144 patients (41.6%) for a median of 268 days (IQR 154, 616). Digoxin use was associated with a significant reduction in cumulative incidence of gastrointestinal bleeding (GIB) (15% vs 26%, p = 0.004). After adjusting for age, hypertension, post-operative hemoglobin, RDW, potassium, and GFR, and use of angiotensin receptor/neprilysin inhibitor, there remained a significant 47% reduction in GIB incidence in patients treated with digoxin. There was no significant difference in cumulative incidence in right ventricular failure (RVF) between the two groups. There was no difference in overall 2-year survival between groups. Digoxin use was associated with reduction in GIB events, but not in RVF or mortality. Further studies are needed to confirm these findings and to investigate optimal timing and patient population.

Tissue plasminogen activator in left ventricular assist device-related intravascular hemolysis after failed augmented anticoagulation.

We sought to examine the efficacy and safety of adding fibrinogen-guided low-dose multi-day Alteplase™ tissue plasminogen activator (tPA) in the management of intravascular hemolysis (IVH) in patients with the HeartMate II (HM-II) continuous flow (CF) left ventricular assist device (LVAD) who failed to achieve IVH resolution with conventional augmented anticoagulation (AAC). IVH in patients with LVAD is often treated with AAC, failing which pump exchange is considered. We hypothesized that a trial of low-dose tPA after failed AAC therapy could resolve IVH and prevent pump exchange in some patients. We performed a retrospective study of 31 HM-II CF LVAD patients admitted to our center from January 2015 to January 2020 for IVH management who received tPA following failed AAC. Primary 6-month outcomes included successful IVH resolution, unsuccessful IVH resolution requiring pump exchange, gastrointestinal bleeding, ischemic and hemorrhagic cerebrovascular accident (CVA), and death. Thirty-one patients with IVH were treated with tPA following failed AAC. Successful resolution of IVH occurred in 22/31 (71%) patients. Pump exchange occurred in 9/31 (29%) patients. Gastrointestinal bleeding occurred in 7/31 (22.6%) patients. Ischemic CVA occurred in 6/31 (19.4%) patients. Management of IVH with administration of low-dose tPA after failed AAC is feasible and may prevent pump exchange in some patients.

Relation of Sociodemographic Factors With Primary Cause of Hospitalization Among Patients With Left Ventricular Assist Devices (from the National Inpatient Sample 2012 to 2017)

Left ventricular assist devices (LVADs) are an established intervention for end-stage heart failure (HF). Rehospitalization for serious complications remains common during the continuous-flow LVAD era. Whether sociodemographic factors are associated with differences in the frequency of severe complications leading to hospitalization remains unclear. Using data from the National Inpatient Sample, we identified all hospitalizations from 2012 to 2017 of adults aged ≥18 years with previous LVAD placement. We categorized the primary cause of hospitalizations into key adverse diagnoses, including bleeding, HF, arrhythmias, LVAD complications, stroke, and a composite of device-related infection or sepsis. We assessed the association of sociodemographic markers with primary diagnoses using modified Poisson regression. We identified 62,630 hospitalizations during the study period (41% aged ≥65, 77% men, 26% Black, 5% Hispanic). Bleeding (18%), infections (15%), and HF (15%) were the most common primary diagnoses. In the multivariable analyses, gastrointestinal bleeding was more likely among older adults (relative risk [RR] 95% confidence interval [CI] 4.69 [3.57 to 6.16]; age ≥65 vs 18 to 44 years), among Black than White patients (RR 95% CI 1.17 [1.04 to 1.32]), and less likely for the highest income quartile than the lowest (RR 95% CI 0.79 [0.69 to 0.91]). Device-related infection/sepsis was also less likely for patients with higher income (RR 95% CI 0.80 [0.67 to 0.96]). Ventricular arrhythmias were less frequent diagnoses for women than men (RR 95% CI 0.59 [0.46 to 0.75]). LVADs complications were less likely in older adults than younger adults (RR 95% CI 0.70 [0.50 to 0.98]). In conclusion, after LVAD implantation, the frequency in which specific adverse events are the primary cause of rehospitalization varies significantly by sociodemographic factors. Further study is needed to determine if there are opportunities for targeted preventive measures based on sociodemographic markers.

Risk Prediction Model for Survival of Wait-List Patients on Axial CF-LVAD: A UNOS Database Analysis

Continuous flow left ventricular assist devices (CF-LVADs) have become a viable option for patients with end-stage heart failure as a bridge to transplantation or the destination therapy. Adult patients listed for heart transplantation (2010-2015) with an axial CF-LVAD on the wait list were obtained from the UNOS database. The multivariate Cox regression model was used to predict the probability of survival after listing. Patients were divided into derivation (80%) and validation (20%) groups. Receiver operating characteristics curves and area under curves were used to define the strength of the model. Risk factors on multivariate analyses were diabetes type I (hazard ratio [HR], 2.5; P=.018), presence of inotropes (HR, 1.6; P=.005), creatinine at listing (HR, 1.2; P < .001). No significant differences were observed between the derivation and validation groups for any of the variables. The area under the curve at 3, 6, and 12 months on the wait list was 0.69, 0.65, 0.63, respectively in the training set and 0.71, 0.65, 0.60, respectively in the validation set. Survival analyses showed that patients implanted with Heartmate II before listing had a better survival than those who were implanted after being on the wait list (HR, 0.78; P=.048). To our knowledge, this was the first time a risk prediction model was generated for wait-list survival of Heartmate II patients. A significant difference in survival was noted between patients who received their Heartmate II before being put on a wait list vs those who were implanted while on the list.

Obesity and outcomes after left ventricular assist device implantation: insights from the EUROMACS Registry.

The objective was to analyse associations between obesity and outcomes after left ventricular assist device (LVAD) implantation. A retrospective analysis of the EUROMACS Registry was performed. Adult patients undergoing primary implantation of a continuous-flow LVAD between 2006 and 2019 were included (Medtronic HeartWare® HVAD®, Abbott HeartMate II®, Abbott HeartMate 3™). Patients were classified into 4 different groups according to body mass index at the time of surgery (body mass index <20 kg/m2: n = 254; 20-24.9 kg/m2: n = 1281; 25-29.9 kg/m2: n = 1238; ≥ 30 kg/m2: n = 691). The study cohort was comprised of 3464 patients. Multivariable Cox proportional cause-specific hazards regression analysis demonstrated that obesity (body mass index ≥30 kg/m2) was independently associated with significantly increased risk of mortality (body mass index ≥30 vs 20-24.9 kg/m2: hazard ratio 1.36, 95% confidence interval 1.18-1.57, overall P < 0.001). Moreover, obesity was associated with significantly increased risk of infection and driveline infection. The probability to undergo heart transplantation was significantly decreased in obese patients (body mass index ≥30 vs 20-24.9 kg/m2: hazard ratio 0.59, 95% confidence interval 0.48-0.74, overall P < 0.001). Obesity at the time of LVAD implantation is associated with significantly higher mortality and increased risk of infection as well as driveline infection. The probability to undergo heart transplantation is significantly decreased. These aspects should be considered when devising a treatment strategy before surgery.

Hypotension on cardiopulmonary stress test predicts 90day mortality after LVAD implantation in INTERMACS 3-6 patients.

Cardiopulmonary stress test (CPX) is routinely performed when evaluating patient candidacy for left ventricular assist device (LVAD) implantation. The predictive value of hypotensive systolic blood pressure (SBP) response during CPX on clinical outcomes is unknown. This study aims to determine the effect of hypotensive SBP response during to clinical outcomes among patients who underwent LVAD implantation. This was a retrospective single center study enrolling consecutive patients implanted with a continuous flow LVAD between 2011 and 2022. Hypotensive SBP response was defined as peak exercise SBP below the resting value. Multivariable Cox-regression analysis was performed to evaluate the relationship between hypotensive SBP response and all-cause mortality within 30 and 90days of LVAD implantation. A subgroup analysis was performed for patients implanted with a HeartMate III (HM III) device. Four hundred thirty-two patients underwent LVAD implantation during the pre-defined period and 156 with INTERMACS profiles 3-6 met our inclusion criteria. The median age was 63years (IQR 54-69), and 52% had ischaemic cardiomyopathy. Hypotensive SBP response was present in 35% of patients and was associated with increased 90day all-cause mortality (unadjusted HR 9.16, 95% CI 1.98-42; P=0.0046). Hazard ratio remained significant after adjusting for age, INTERMACS profile, serum creatinine, and total bilirubin. Findings were similar in the HM III subgroup. Hypotensive SBP response on pre-LVAD CPX is associated with increased perioperative and 90day mortality after LVAD implantation. Additional studies are needed to determine the mechanism of increased mortality observed.