Continuous-flow Left Ventricular Assist Device Research Articles

A prospective multicenter feasibility study of a miniaturized implantable continuous flow ventricular assist device in smaller children with heart failure

There is no FDA-approved left ventricular assist device (LVAD) for smaller children permitting routine hospital discharge. Smaller children supported with LVADs typically remain hospitalized for months awaiting heart transplant-a major burden for families and a challenge for hospitals. We describe the initial outcomes of the Jarvik 2015, a miniaturized implantable continuous flow LVAD, in the NHLBI-funded Pumps for Kids, Infants, and Neonates (PumpKIN) study, for bridge-to-heart transplant. Children weighing 8 to 30 kg with severe systolic heart failure and failing optimal medical therapy were recruited at 7 centers in the United States. Patients with severe right heart failure and single-ventricle congenital heart disease were excluded. The primary feasibility endpoint was survival to 30 days without severe stroke or non-operational device failure. Of 7 children implanted, the median age was 2.2 (range 0.7, 7.1) years, median weight 10 (8.2 to 20.7) kilograms; 86% had dilated cardiomyopathy; 29% were INTERMACS profile 1. The median duration of Jarvik 2015 support was 149 (range 5 to 188) days where all 7 children survived including 5 to heart transplant, 1 to recovery, and 1 to conversion to a paracorporeal device. One patient experienced an ischemic stroke on day 53 of device support in the setting of myocardial recovery. One patient required ECMO support for intractable ventricular arrhythmias and was eventually transplanted from paracorporeal biventricular VAD support. The median pump speed was 1600 RPM with power ranging from 1-4 Watts. The median plasma free hemoglobin was 19, 30, 19 and 30 mg/dL at 7, 30, 90 and 180 days or time of explant, respectively. All patients reached the primary feasibility endpoint. Patient-reported outcomes with the device were favorable with respect to participation in a full range of activities. Due to financial issues with the manufacturer, the study was suspended after consent of the eighth patient. The Jarvik 2015 LVAD appears to hold important promise as an implantable continuous flow device for smaller children that may support hospital discharge. The FDA has approved the device to proceed to a 22-subject pivotal trial. Whether this device will survive to commercialization remains unclear because of the financial challenges faced by industry seeking to develop pediatric medical devices. (Supported by NIH/NHLBI HHS Contract N268201200001I, clinicaltrials.gov 02954497).

(60) - Dynamic and Structural Ophthalmic Evaluation of Continuous-Flow Left Ventricular Assist Device Patients

(60) - Dynamic and Structural Ophthalmic Evaluation of Continuous-Flow Left Ventricular Assist Device Patients

(432) - Impact of Blood Type on Pre- and Post-Transplant Outcomes in Patients with Continuous-Flow Left Ventricular Assist Devices Listed for Orthotopic Heart Transplant

(432) - Impact of Blood Type on Pre- and Post-Transplant Outcomes in Patients with Continuous-Flow Left Ventricular Assist Devices Listed for Orthotopic Heart Transplant

(61) - Computational Fluid Dynamics Modelling of the Effect of Outflow Graft Flow on Vessel Wall Deformation: Possible Implications for Aortic Regurgitation Development in Patients with Continuous-Flow LVAD

(61) - Computational Fluid Dynamics Modelling of the Effect of Outflow Graft Flow on Vessel Wall Deformation: Possible Implications for Aortic Regurgitation Development in Patients with Continuous-Flow LVAD

(1193) - Percutaneous Left Atrial Appendage Occlusion Devices and Continuous Flow LVAD Thrombosis: An Occult Source of VAD Thrombosis?

(1193) - Percutaneous Left Atrial Appendage Occlusion Devices and Continuous Flow LVAD Thrombosis: An Occult Source of VAD Thrombosis?

Predictors and Impact of Prolonged Vasoplegia After Continuous-Flow Left Ventricular Assist Device Implantation

BackgroundVasoplegia after cardiac surgery is associated with adverse outcomes. However, the clinical effects of vasoplegia and the significance of its duration after continuous-flow left ventricular assist device (CF-LVAD) implantation are less known. ObjectivesThis study aimed to identify predictors of and outcomes from transient vs prolonged vasoplegia after CF-LVAD implantation. MethodsThe study was a retrospective review of consecutive patients who underwent CF-LVAD implantation between January 1, 2005, and December 31, 2017. Vasoplegia was defined as the presence of all of the following: mean arterial pressure ≤65 mm Hg, vasopressor (epinephrine, norepinephrine, vasopressin, or dopamine) use for >6 hours within the first 24 hours postoperatively, cardiac index ≥2.2 L/min/m2 and systemic vascular resistance <800 dyne/s/cm5, and vasodilatory shock not attributable to other causes. Prolonged vasoplegia was defined as that lasting 12 to 24 hours; transient vasoplegia was that lasting 6 to <12 hours. Patient characteristics, outcomes, and risk factors were analyzed. ResultsOf the 600 patients who underwent CF-LVAD implantation during the study period, 182 (30.3%) developed vasoplegia. Mean patient age was similar between the vasoplegia and no-vasoplegia groups. Prolonged vasoplegia (n = 78; 13.0%), compared with transient vasoplegia (n = 104; 17.3%), was associated with greater 30-day mortality (16.7% vs 5.8%; P = 0.02). Risk factors for prolonged vasoplegia included preoperative dialysis and elevated body mass index. ConclusionsCompared with vasoplegia overall, prolonged vasoplegia was associated with worse survival after CF-LVAD implantation. Treatment to avoid or minimize progression to prolonged vasoplegia may be warranted.

Kidney Function Trajectories and Right Heart Failure Following LVAD Implantation.

Preoperative kidney dysfunction is a risk factor for right heart failure (RHF) after implantation of a left ventricular assist device (LVAD). However, characteristic kidney function trajectories before and after post-LVAD RHF are uncertain, so we investigated this. We identified individuals who received primary continuous-flow LVAD implantation from July 1, 2014 to December 31, 2017 in the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) data set. Incident RHF was ascertained using the INTERMACS definition at 1 and 3 months and classified as transient or persistent. Kidney function trajectories before and after RHF onset, and relationships of baseline kidney function with RHF risk at the different time points, were assessed. We identified 8076 LVAD recipients who met inclusion criteria. Incident RHF was present at 1 month in 26.4%. There were 4850 individuals with follow-up at 3 months, with incident RHF in 4.2%. Kidney function trajectories differed from pre-LVAD implantation to 1-month follow-up by RHF category, with those developing persistent RHF having no improvement in baseline kidney function. For trajectories before the 3-month RHF ascertainment time, the shape was similar for those with and without RHF, with lower estimated glomerular filtration rate levels among those who developed RHF. Baseline estimated glomerular filtration rate levels below the normal range were associated with higher risk of RHF at 1 and 3 months. In LVAD recipients, preimplantation kidney function and subsequent kidney function trajectories differed substantially by RHF at 1 and 3 months postimplantation, even after adjustment for several confounders. This may demonstrate bidirectional associations between kidney function and right ventricular function in LVAD recipients.

Epidemiology and Risk Factors for Nosocomial Infections in Left Ventricular Assist Device Recipients.

Left ventricular assist devices (LVADs) have been increasingly used as a valid option to improve the prognosis and reduce the symptoms of end-stage heart failure. However, long-term complications, mostly infections and coagulation disorders, are frequent. We described the epidemiology and risk factors for nosocomial infections (NIs) in a cohort of adult patients who underwent continuous-flow LVAD implant between January 2010 and December 2017 in Turin, Italy. Secondary outcomes were the prevalence of multidrug-resistant (MDR) bacteria and mortality. Results: Overall, 64 LVADs were implanted. A total of 32 (50%) patients experienced at least one episode of NI, with a total of 46 infectious events. VAD-related infections occurred in 22 patients (68.8%). Non VAD-related NIs occurred in 12 patients (37.5%), mainly low respiratory tract infections. Length of intensive care unit admission was a risk factor for NI (OR 1.224, 95%CI; 1.049, 1.429). Gram-negative bacilli were responsible for 58.8% of VAD-related infections and 79.5% of non-VAD related infections. In sixteen patients (50%), at least one episode of infection was related to an MDR strain. INTERMACS class and length of MV were independent risk factors for NIs by MDR strains (respectively, OR 2.12, 95%CI: 1.08, 6.80; p = 0.02 and OR 1.46, 95%CI: 1.07, 5.52, p = 0.047). In-hospital mortality was 6.3%. No differences in mortality were observed between infected and non-infected patients (p = 0.61) even when caused by MDR strains (p = 0.143). Conclusion: the rate of nosocomial infections in LVAD patients is associated with the length of ICU admission, and the etiology of nosocomial infection after LVAD implant is mainly due to GNB, including a high rate of MDR strains, especially KPC-KP and MDR PA.

Surgical Outcomes of Centrifugal Continuous-Flow Implantable Left Ventricular Assist Devices: Heartmate 3 versus Heartware Ventricular Assist Device.

Left ventricular assist devices (LVADs) are widely employed as a therapeutic option for end-stage heart failure. We evaluated the outcomes associated with centrifugal-flow LVAD implantation, comparing 2 device models: the Heartmate 3 (HM3) and the Heartware Ventricular Assist Device (HVAD). Data were collected from patients who underwent LVAD implantation between June 1, 2015 and December 31, 2022. We analyzed overall survival, first rehospitalization, and early, late, and LVAD-related complications. In total, 74 patients underwent LVAD implantation, with 42 receiving the HM3 and 32 the HVAD. A mild Interagency Registry for Mechanically Assisted Circulatory Support score was more common among HM3 than HVAD recipients (p=0.006), and patients receiving the HM3 exhibited lower rates of preoperative ventilator use (p=0.010) and extracorporeal membrane oxygenation (p=0.039). The overall early mortality rate was 5.4% (4 of 74 patients), with no significant difference between groups. Regarding early right ventricular (RV) failure, HM3 implantation was associated with a lower rate (13 of 42 [31.0%]) than HVAD implantation (18 of 32 [56.2%], p=0.051). The median rehospitalization-free period was longer for HM3 recipients (16.9 months) than HVAD recipients (5.3 months, p=0.013). Furthermore, HM3 recipients displayed a lower incidence of late hemorrhagic stroke (p=0.016). In the multivariable analysis, preoperative use of continuous renal replacement therapy (odds ratio, 22.31; p=0.002) was the only significant predictor of postoperative RV failure. The LVAD models (HM3 and HVAD) demonstrated comparable overall survival rates. However, the HM3 was associated with a lower risk of late hemorrhagic stroke.

Improving the Prediction of 1 Year Right Ventricular Failure After Left Ventricular Assist Device Implantation.

Previous predictive models for postimplant right heart failure (RHF) following left ventricular assist device (LVAD) implantation have demonstrated limited performance on validation datasets and are susceptible to overfitting. Thus, the objective of this study was to develop an improved predictive model with reduced overfitting and improved accuracy in predicting RHF in LVAD recipients. The study involved 11,967 patients who underwent continuous-flow LVAD implantation between 2008 and 2016, with an RHF incidence of 9% at 1 year. Using an eXtreme Gradient Boosting (XGBoost) algorithm, the training data were used to predict RHF at 1 year postimplantation, resulting in promising area under the curve (AUC)-receiver operating characteristic (ROC) of 0.8 and AUC-precision recall curve (PRC) of 0.24. The calibration plot showed that the predicted risk closely corresponded with the actual observed risk. However, the model based on data collected 48 hours before LVAD implantation exhibited high sensitivity but low precision, making it an excellent screening tool but not a diagnostic tool.

Right heart reserve function assessed with fluid loading predicts late right heart failure after left ventricular assist device implantation.

BackgroundA left ventricular assist device (LVAD) is an effective therapeutic option for advanced heart failure. Late right heart failure (LRHF) is a complication after LVAD implantation associated with increasing morbidity and mortality; however, the assessment of right heart function, including right heart reserve function after LVAD implantation, has not been established. We focused on a fluid loading test with right heart catheterization (RHC) to evaluate right heart pre-load reserve function and investigate its impact on LRHF. MethodsPatients aged > 18 who received continuous-flow LVAD between November 2007 and December 2022 at our institution and underwent RHC with saline loading (10ml/kg for 15 min) 1 month after LVAD implantation were included. ResultsOverall, 31 LRHF or deaths (RHF group) have occurred in 149 patients. Comparing the RHF and non-RHF groups, pulmonary artery pulsatility index (PAPi) at rest (1.8±0.89 vs. 2.5±1.4, p=0.02) and right ventricular stroke work index (RVSWi) change ratio with saline loading (0.96±0.32 vs. 1.1±0.20, p=0.03) was significantly different. The PAPi at rest and RVSWi change ratio with saline loading were identified as the postoperative risks for LRHF or death. The cohort was divided into three groups based on whether the PAPi at rest and RVSWi change ratio were low. The event-free curve significantly differed between the three groups (p<0.001). ConclusionsHemodynamic assessment with saline loading can evaluate the right ventricular pre-load reserve function of patients with LVAD. The low RVSWi change with saline loading was a risk factor for LRHF following LVAD implantation.

Machine Learning Multicenter Risk Model to Predict Right Ventricular Failure After Mechanical Circulatory Support

The existing models predicting right ventricular failure (RVF) after durable left ventricular assist device (LVAD) support might be limited, partly due to lack of external validation, marginal predictive power, and absence of intraoperative characteristics. To derive and validate a risk model to predict RVF after LVAD implantation. This was a hybrid prospective-retrospective multicenter cohort study conducted from April 2008 to July 2019 of patients with advanced heart failure (HF) requiring continuous-flow LVAD. The derivation cohort included patients enrolled at 5 institutions. The external validation cohort included patients enrolled at a sixth institution within the same period. Study data were analyzed October 2022 to August 2023. Study participants underwent chronic continuous-flow LVAD support. The primary outcome was RVF incidence, defined as the need for RV assist device or intravenous inotropes for greater than 14 days. Bootstrap imputation and adaptive least absolute shrinkage and selection operator variable selection techniques were used to derive a predictive model. An RVF risk calculator (STOP-RVF) was then developed and subsequently externally validated, which can provide personalized quantification of the risk for LVAD candidates. Its predictive accuracy was compared with previously published RVF scores. The derivation cohort included 798 patients (mean [SE] age, 56.1 [13.2] years; 668 male [83.7%]). The external validation cohort included 327 patients. RVF developed in 193 of 798 patients (24.2%) in the derivation cohort and 107 of 327 patients (32.7%) in the validation cohort. Preimplant variables associated with postoperative RVF included nonischemic cardiomyopathy, intra-aortic balloon pump, microaxial percutaneous left ventricular assist device/venoarterial extracorporeal membrane oxygenation, LVAD configuration, Interagency Registry for Mechanically Assisted Circulatory Support profiles 1 to 2, right atrial/pulmonary capillary wedge pressure ratio, use of angiotensin-converting enzyme inhibitors, platelet count, and serum sodium, albumin, and creatinine levels. Inclusion of intraoperative characteristics did not improve model performance. The calculator achieved a C statistic of 0.75 (95% CI, 0.71-0.79) in the derivation cohort and 0.73 (95% CI, 0.67-0.80) in the validation cohort. Cumulative survival was higher in patients composing the low-risk group (estimated <20% RVF risk) compared with those in the higher-risk groups. The STOP-RVF risk calculator exhibited a significantly better performance than commonly used risk scores proposed by Kormos et al (C statistic, 0.58; 95% CI, 0.53-0.63) and Drakos et al (C statistic, 0.62; 95% CI, 0.57-0.67). Implementing routine clinical data, this multicenter cohort study derived and validated the STOP-RVF calculator as a personalized risk assessment tool for the prediction of RVF and RVF-associated all-cause mortality.

Sex Disparities in Left Ventricular Assist Device Implantation: Delayed Presentation and Worse Right Heart Failure.

We explored whether women undergo continuous-flow left ventricular assist device (CF-LVAD) implantation in later stages of heart failure (HF) than men, evidenced by worse preoperative right HF (RHF). We also compared two propensity models with and without preoperative RHF to assess its effect on outcomes. INTERMACS was queried from July 2008 to December 2017. Propensity model 1 matched men and women on age ≥50 years, HF etiology, body surface area, INTERMACS class, comorbidities, device strategy, temporary mechanical circulatory support, and device type. Model 2 included these variables plus LV end-diastolic diameter, right atrial pressure/pulmonary capillary wedge pressure, pulmonary artery pulsatility index, and right ventricular ejection fraction. The primary outcome was all-cause mortality. Secondary outcomes comprise RHF, rehospitalization, renal dysfunction, stroke, and device malfunction. In model 1, characteristics were comparable between 3,195 women and 3,195 men, except women more often had preoperative RHF and postoperative right VAD support and had worse 1 year and overall survival. In model 2, after propensity matching for additional risk factors for preoperative RHF, 1,119 women and 1,119 men had comparable post-LVAD implant RVAD use and survival. These findings suggest that women present more often with biventricular failure and after implantation have higher RHF and mortality rates.

Continuous Flow Lvad And Home Sleep Apnea Testing: Is It Feasible?

Continuous Flow Lvad And Home Sleep Apnea Testing: Is It Feasible?

Managing ventricular arrhythmias and implantable cardiac defibrillator shocks after left ventricular assist device implantation.

Continuous flow left ventricular assist devices (CF-LVADs) have been shown to reduce mortality and morbidity in patients with advanced heart failure with reduced ejection fraction. However, ventricular arrhythmias (VA) are common, are mostly secondary to underlying myocardial scar, and have a higher incidence in patients with pre-LVAD VA. Sustained VA is well tolerated in the LVAD patient but can result in implantable defibrillator (ICD) shocks, right ventricular failure, hospitalizations, and reduced quality of life. There is limited data regarding best practices for the medical management of VA as well as the role for procedural interventions in patients with uncontrolled VA and/or ICD shocks. Vast majority of CF-LVAD patients have a preexisting cardiovascular implantable electronic device (CIED) and ICD and/or cardiac resynchronization therapies are continued in many. Several questions, however, remain regarding the efficacy of ICD and CRT following CF-LVAD. Moreover, optimal CIED programming after CF-LVAD implantation. Therefore, the primary objective of this review article is to provide the most up-to-date evidence and to provide guidance on the clinical significance, pathogenesis, predictors, and management strategies for VA and ICD therapies in the CF-LVAD population. We also discuss knowledge gaps as well as areas for future research.

Aspirin and Hemocompatibility Events With a Left Ventricular Assist Device in Advanced Heart Failure

Left ventricular assist devices (LVADs) enhance quality and duration of life in advanced heart failure. The burden of nonsurgical bleeding events is a leading morbidity. Aspirin as an antiplatelet agent is mandated along with vitamin K antagonists (VKAs) with continuous-flow LVADs without conclusive evidence of efficacy and safety. To determine whether excluding aspirin as part of the antithrombotic regimen with a fully magnetically levitated LVAD is safe and decreases bleeding. This international, randomized, double-blind, placebo-controlled study of aspirin (100 mg/d) vs placebo with VKA therapy in patients with advanced heart failure with an LVAD was conducted across 51 centers with expertise in treating patients with advanced heart failure across 9 countries. The randomized population included 628 patients with advanced heart failure implanted with a fully magnetically levitated LVAD (314 in the placebo group and 314 in the aspirin group), of whom 296 patients in the placebo group and 293 in the aspirin group were in the primary analysis population, which informed the primary end point analysis. The study enrolled patients from July 2020 to September 2022; median follow-up was 14 months. Patients were randomized in a 1:1 ratio to receive aspirin (100 mg/d) or placebo in addition to an antithrombotic regimen. The composite primary end point, assessed for noninferiority (-10% margin) of placebo, was survival free of a major nonsurgical (>14 days after implant) hemocompatibility-related adverse events (including stroke, pump thrombosis, major bleeding, or arterial peripheral thromboembolism) at 12 months. The principal secondary end point was nonsurgical bleeding events. Of the 589 analyzed patients, 77% were men; one-third were Black and 61% were White. More patients were alive and free of hemocompatibility events at 12 months in the placebo group (74%) vs those taking aspirin (68%). Noninferiority of placebo was demonstrated (absolute between-group difference, 6.0% improvement in event-free survival with placebo [lower 1-sided 97.5% CI, -1.6%]; P < .001). Aspirin avoidance was associated with reduced nonsurgical bleeding events (relative risk, 0.66 [95% confidence limit, 0.51-0.85]; P = .002) with no increase in stroke or other thromboembolic events, a finding consistent among diverse subgroups of patient characteristics. In patients with advanced heart failure treated with a fully magnetically levitated LVAD, avoidance of aspirin as part of an antithrombotic regimen, which includes VKA, is not inferior to a regimen containing aspirin, does not increase thromboembolism risk, and is associated with a reduction in bleeding events. ClinicalTrials.gov Identifier: NCT04069156.

Bridging therapy and risk of major bleeding and thrombosis in continuous-flow left ventricular assist device patients: a quasi-experimental study

Abstract Background Bridging with low molecular weight heparin (LMWH) on top of vitamin K antagonist treatment is recommended in continuous-flow left ventricular assist device (CF-LVAD) patients during subtherapeutic anticoagulation. However, the consequence of bridging on the risk of bleeding and thrombosis are unknown. Aim To assess the risk of major bleeding and thrombosis associated with bridging in CF-LVAD patients, through a regression discontinuity (RD) design, a quasi-experimental design. Methods We included CF-LVAD patients implanted at our university medical center between 2010-2021. Outcomes were major bleeding (INTERMACS type 3, 4, 5) and thromboembolic events (pump thrombosis, arterial non-central nervous system and venous thromboembolism). We estimated incidence rates and hazard ratios (HR) with 95% confidence intervals (95%CI) by time-dependent Cox regression. Using an RD design, a quasi-experimental design, we compared patients using LMWH due to a subtherapeutic international normalized ratio (INR) to patients with no LMWH and an INR just in target range. As LMWH treatment is initiated based on an INR threshold (i.e., when INR is below the lower target range) and INR is subject to random variability, patients just below and in the INR target range are comparable, mimicking a randomized trial. Analyses were performed five times including INRs±0.1, ±0.2, ±0.3, ±0.4 and ±0.5 around the INR threshold. Results 77 patients were included, with a median age at implantation of 69 years, 60 (78%) were male, 45 (58%) had ischemic heart failure and 35 (45%) had INTERMACS classification 3. We included 35,466 INRs during 91 patient-years of follow-up. Bridging was associated with increased major bleeding rates compared to no-bridging in all analyses (Figure 1). In particular, the risk of major bleeding was 6.9-fold increased (95%CI 1.2-38.9) during bridging compared to no-bridging considering INR+0.1, and 3.4-fold (95%CI 1.4-8.2) considering INR±0.5 (Figure 2A). While thrombotic events were infrequent, the risk of thrombosis was around unity during bridging compared to no-bridging considering INR±0.5 (HR 1.1, 95%CI 0.1-9.9, Figure 2B). Conclusions During bridging with LMWH, CF-LVAD patients had a 6.9-fold increased risk of major bleeding, while the risk of thrombosis was around unity compared to no-bridging.Incidence ratesHazard ratios

Abstract 15424: Phase-to-Phase Short Phenomenon in a Left Ventricular Assist Device: Navigating Through Clinical and Ethical Challenges

Description of Case A 59-year-old male with an axial continuous-flow left ventricular assist device (CF-LVAD) presented asymptomatically after noticing low-flow alarms. He reported extensive external driveline damage that accumulated over one year. The CF-LVAD was connected to an ungrounded cable and the driveline was repaired by the manufacturer. However, low-flow alarms continued. Log files revealed pump stoppages on all modes of power which was compatible with phase-to-phase short phenomenon (PtPSP). The patient was cannulated in case of emergent need for ECMO and upgraded to UNOS status 1 for heart transplant. Because PtPSP was considered unrepairable, the patient underwent emergent cardiac transplantation. Discussion The CF-LVAD driveline consists of three phases, each of which is formed by two electrical wires, connected to six motor stators. PtPSP causes driveline dysfunction due to a loss of insulation between the three phases owing to multiple breaches of the insulator, causing the pump to lose power when the damaged phases come into contact. Pump stoppages are likely and unpredictable even on batteries or an ungrounded cable. Patients may notice alarms associated with low flow, pump speed drops, or pump arrest. PtPSP is unrepairable, and pump exchange or urgent heart transplantation are the only viable treatment options.This case highlights the ethical complexity of the care of patients with advanced heart failure, whereby subjective treatment decisions often translate to objectively different levels of priority on the heart transplantation waiting list without intrinsic measures of disease severity, which may incentivize more aggressive care. Conclusions: CF-LVAD driveline dysfunction due to PtPSP is a clinically asymptomatic ominous scenario often uncovered by pump-controller alarms. Given the high risk of abrupt pump stoppage, a diagnosis of PtPSP necessitates emergent device exchange or explant with an orthotopic heart transplantation.

Abstract 13838: Hemostatic Disorder During Left Ventricular Assist Device Implantation in Swine

Introduction: Implantation of left ventricular assist devices (LVAD) conventionally requires the use of cardiopulmonary bypass (CPB). Among others, mechanical circulatory support devices favor intraoperative hemostatic disorder. Hypothesis: Despite the high risk of severe bleeding and thromboembolic complications, little is known about the intraoperative extent of hemostatic disorder during LVAD implantation.This study aimed to determine the extent of hemostatic disorder during LVAD implantation in a porcine model under CPB and LVAD support, separately. Methods: We performed LVAD implantation in 10 female German Landrace pigs (body weight 104 ± 13 kg). Blood samples were collected three times: at (1) Baseline, (2) after CPB and (3) after LVAD. For CPB, cannulation of the left jugular vein and right femoral artery was performed. After sternotomy and pericardiotomy, apical coring was performed under CPB. A continuous-flow LVAD with transventricular outflow graft was implanted. For CPB and LVAD, a flow rate of 3-7 L/min and a rotational speed of 4000 to 7200 rpm were aimed, respectively. Hemostatic laboratory markers from all times were compared by Wilcoxon signed rank test. Results: Compared to Baseline, CPB led to a significant decrease of fibrinogen and antithrombin as well as an increase of von Willebrand factor (vWF) ratio and D dimer (DD). Compared to after CPB, there was a continued decrease of antithrombin and an increase of DD, as well as a significant increase of vWF and vWF activity under LVAD support. Conclusion: Among others, CPB and LVAD separately contribute to hemostatic disorder during LVAD implantation. Human laboratory markers allowed early detection of intraoperative hemostatic changes in pigs. Further studies are needed to investigate whether off-pump LVAD implantation reduces perioperative hemostatic disorder.

Abstract 12859: Clinical Correlates and Prognostic Value of B-type Natriuretic Peptide in Left Ventricular Assist Device Recipients With Cardiogenic Shock: Insights From INTERMACS

Introduction: B-type natriuretic peptide (BNP) is a robust predictor of outcomes across the heart failure (HF) spectrum. However, data characterizing BNP levels in end-stage HF with cardiogenic shock (CS) is lacking. Furthermore, the prognostic value of BNP in left ventricular assist device (LVAD) receiving Stage D HF patients with CS has not been assessed previously. Methods: Continuous flow LVAD recipients with CS enrolled in INTERMACS between 2005 to 2017 were included. CS was defined as INTERMACS profile 1-3. The primary outcome of the study was long-term mortality. Long-term mortality was assessed in patients alive at 1-month post-surgery. Secondary outcomes included peri-operative mortality (&lt;30 days of surgery), cardiovascular mortality, arrhythmia, and right HF. The cohort was stratified by quartiles of BNP levels. Multivariable Cox proportional hazard models, adjusted for age, sex, body mass index, INTERMACS profile, center volume, implantation year, device strategy, estimated glomerular filtration rate, employment status, and education level, were used to assess the association between BNP levels and outcomes. Results: Among 7,290 LVAD recipients with CS, the median pre-implantation BNP value was 859 (427, 1,614) pg/mL. Males [851(429, 1,557) pg/mL, P =0.07], non-Hispanic Blacks [777 (362, 1,514) pg/mL, P =&lt;0.001], and obese [642 (311, 1,170) pg/mL, P =&lt;0.001] patients had lower BNP values. Over a median follow-up of 14.7 (6.9, 28.7) months, the risk of long-term mortality was similar in the second [HR adj :1.06 (0.94-1.20)], third [HR adj :0.97 (0.85-1.10)], and fourth [HR adj :1.04 (0.91-1.18)] quartiles of BNP compared with the first quartile of BNP. Similarly, the risk of peri-operative mortality, cardiovascular mortality, arrhythmia, and right HF did not vary by the quartiles of BNP. Conclusions: BNP has poor prognostic value in LVAD recipients with CS and the value of routine measurement of BNP in this population needs further investigation.