Fully magnetically centrifugal left ventricular assist device and long-term outcomes: the ELEVATE registry.

BACKGROUND AND AIMS: HeartMate 3 (HM3) is a fully magnetically levitated continuous flow left ventricular assist device, which received CE marking in 2015. The ELEVATE Registry was initiated to collect real-world outcomes in patients treated with HM3 post-CE Mark approval. METHODS: A total of 540 subjects implanted at 26 centres between March 2015 and February 2017 were included in this registry. Of these, 463 received the device as a primary implant (primary implant cohort, PIC), 19 as a pump exchange (pump exchange cohort), and in 58 patients, only anonymized survival data were collected (anonymized cohort, AC). Patients in the PIC contributed to the baseline demographics, survival, adverse events, quality of life (QoL) (EuroQoL-5 Dimensions-5 Levels visual analogue scale), and functional capacity (6 min walk distance) assessments, while patients in the AC contributed only to survival. RESULTS: Primary implant cohort patients had a mean age of 56 years and were predominantly male (89%) with 48% ischaemic aetiology. The majority of subjects was designated bridge to transplant (66%) and had INTERMACS Profiles 1-3 (70%). At baseline, the subjects had poor functional capacity (104 ± 140 m) and impaired QoL (35 ± 19 points). The overall survival rate of the PIC was 63.3% and survival free of stroke was 58.1% at 5 years. Significant improvements in functional capacity and QoL were observed and maintained for 5 years (301 ± 131 m and 64 ± 20 points, respectively). CONCLUSIONS: Real-world data from the ELEVATE registry demonstrate an overall survival rate for primary implants of 63.3%. In the PIC, reductions in adverse events for patients in the extended follow-up and improved QoL and functional capacity were observed at 5 years in this patient population with advanced heart failure.

OPTN/SRTR 2022 Annual Data Report: Heart.

The number of heart transplants in the United States has continued to increase. Since 2011, pediatric heart transplants have increased 31.7% to 494 and adult heart transplants have increased 85.8% to 3,668 in 2022. The numbers of new candidates for pediatric and adult heart transplants have also increased, with 703 new pediatric candidates and 4,446 new adult candidates in 2022. Adult heart transplant rates continue to rise, peaking at 122.5 transplants per 100 patient-years in 2022; however, the pediatric heart transplant rate decreased to its lowest rate in the past decade, 104.2 transplants per 100 patient-years, a decrease of 13.9% from 121 transplants per 100 patient-years in 2011. Despite this, pretransplant mortality among pediatric candidates has decreased by 52.2%, from 20.8 deaths per 100 patient-years in 2011 to 10.0 deaths per 100 patient-years in 2022, but remains excessive for candidates younger than 1 year at 25.7 deaths per 100 patient-years. Among adult candidates, pretransplant mortality declined from 15 deaths per 100 patient-years in 2011 to 8.7 deaths per 100 patient-years in 2022. Since 2011, posttransplant mortality has been stable to slightly better; among recipients who underwent transplant in 2015-2017, the 1-, 3-, and 5-year pediatric survival rates were 93.7%, 89.2%, and 85.0%, respectively, and the adult survival rates were 91.3%, 85.7%, and 80.4%. Donor trends have been favorable, with an increase in the numbers of hearts recovered and growing numbers of hearts procured after circulatory death.

Electrical storm after left ventricular assist device (LVAD) implantation.

INTRODUCTION: Ventricular tachycardia storm or electrical storm (ES) is a common complication following left ventricular assist device (LVAD) implantation. The factors contributing to ES and outcomes are less studied. The study aimed to determine the factors associated with ES and the probability of survival in patients undergoing LVAD in three tertiary centers over a span of 15 years. METHODS: We performed a retrospective cohort study on all patients who underwent LVAD implantation at the Mayo Clinic (Rochester, Phoenix, and Jacksonville) from January 1, 2006 to December 31, 2020. ES was defined as ≥3 episodes of sustained ventricular tachycardia over a period of 24 h with no identifiable reversible cause. Detailed chart reviews of the electronic health records within the Mayo Clinic and outside medical records were performed. RESULTS: A total of 883 patients who underwent LVAD implantation were included in our study. ES occurred in 7% (n = 61) of patients with a median of 13 days (interquartile range [IQR]: 5-297 days) following surgery. We found 57% of patients (n = 35) developed ES within 30 days, while 43% (n = 26) patients developed ES at a median of 545  (IQR 152-1032) days after surgery. Following ES, 26% of patients died within 1 year. Patients with ES had a significant association with a history of ventricular arrhythmias and implantable cardioverter defibrillator (ICD) shocks before the procedure. ES was significantly associated with reduced survival compared to patients without ES (hazards ratio [HR]: 1.92, 95% CI: 1.39-2.64, p < .001). CONCLUSION: Following LVAD implantation, the rate of ES was 7% with majority of ES occurring within 30 days of LVAD. Risk factors for ES included pre-implant history of ventricular arrhythmias and ICD shock. ES was significantly associated with reduced survival compared to patients without ES.

Cardiac stereotactic radiation therapy for refractory ventricular arrhythmias in patients with left ventricular assist devices.

Left ventricular assist device (LVAD) implantation is an established treatment for patients with advanced heart failure refractory to medical therapy. However, the incidence of ventricular arrhythmias (VAs) is high in this population, both in the acute and delayed phases after implantation. About one-third of patients implanted with an LVAD will experience sustained VAs, predisposing these patients to worse outcomes and complicating patient management. The combination of pre-existing myocardial substrate and complex electrical remodeling after LVAD implantation account for the high incidence of VAs observed in this population. LVAD patients presenting VAs refractory to antiarrhythmic therapy and catheter ablation procedures are not rare. In such patients, treatment options are extremely limited. Stereotactic body radiation therapy (SBRT) is a technique that delivers precise and high doses of radiation to highly defined targets, reducing exposure to adjacent normal tissue. Cardiac SBRT has recently emerged as a promising alternative with a growing number of case series reporting the effectiveness of the technique in reducing the VA burden in patients with arrhythmias refractory to conventional therapies. The safety profile of cardiac SBRT also appears favorable, even though the current clinical experience remains limited. The use of cardiac SBRT for the treatment of refractory VAs in patients implanted with an LVAD are even more scarce. This review summarizes the clinical experience of cardiac SBRT in LVAD patients and describes technical considerations related to the implementation of the SBRT procedure in the presence of an LVAD.

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.

Early Ventricular Arrhythmias After Left Ventricular Assist Device Implantation.

BACKGROUND: Although sustained ventricular arrhythmias (VAs) are a common complication after durable left ventricular assist device (LVAD) implantation, the incidence, risk factors, and prognostic implications of postoperative early VAs (EVAs) in contemporary patients with LVAD are poorly understood. METHODS AND RESULTS: A single-center retrospective analysis was performed of patients who underwent LVAD implantation from October 1, 2006, to October 1, 2022. EVA was defined as an episode of sustained VA identified ≤30 days after LVAD implantation. A total of 789 patients underwent LVAD implantation (mean age 62.9 ± 0. years 5, HeartMate 3 41.4%, destination therapy 43.3%). EVAs occurred in 100 patients (12.7%). A history of end-stage renal disease (odds ratio [OR] 5.6, 95% confidence interval [CI] 1.45-21.70), preoperative electrical storm (OR 2.82, 95% CI 1.11-7.16), and appropriate implantable cardiac defibrillator therapy before implantation (OR 2.8, 95% CI 1.26-6.19) are independently associated with EVAs. EVA was associated with decreased 30-day survival (hazard ratio 3.02, 95% CI 1.1-8.3, P = .032). There was no difference in transplant-free survival time between patients with and without EVAs (hazard ratio 0.82, 95% CI 0.5-1.4, P = .454). CONCLUSIONS: EVAs are common after durable LVAD implantation and are associated with an increased risk of 30-day mortality.

The Future of Durable Mechanical Circulatory Support: Emerging Technological Innovations and Considerations to Enable Evolution of the Field.

The field of durable mechanical circulatory support (MCS) has undergone an incredible evolution over the past few decades, resulting in significant improvements in longevity and quality of life for patients with advanced heart failure. Despite these successes, substantial opportunities for further improvements remain, including in pump design and ancillary technology, perioperative and postoperative management, and the overall patient experience. Ideally, durable MCS devices would be fully implantable, automatically controlled, and minimize the need for anticoagulation. Reliable and long-term total artificial hearts for biventricular support would be available; and surgical, perioperative, and postoperative management would be informed by the individual patient phenotype along with computational simulations. In this review, we summarize emerging technological innovations in these areas, focusing primarily on innovations in late preclinical or early clinical phases of study. We highlight important considerations that the MCS community of clinicians, engineers, industry partners, and venture capital investors should consider to sustain the evolution of the field.

Biosensors with left ventricular assist devices.

Heart failure imposes a significant global health burden, standing as a primary contributor to mortality. Various indicators and physiological shifts within the body may hint at distinct cardiac conditions. Specific biosensors have the capability to identify these changes. Integrating or embedding these biosensors into mechanical circulatory support devices (MCSDs), such as left ventricular assist devices (LVADs), becomes crucial for monitoring alterations in biochemical and physiological factors subsequent to an MCSD implantation. Detecting abnormal changes early in the course of disease progression will allow for improved patient outcomes and prognosis following an MCSD implantation. The aim of this review is to explore the available biosensors that may be coupled or implanted alongside LVADs to monitor biomarkers and changes in physiological parameters. Different fabrication materials for the biosensors are discussed, including their advantages and disadvantages. This review also examines the feasibility of integrating feedback control mechanisms into LVAD systems using data from the biosensors. Challenges facing this emerging technology and future directions for research and development are outlined as well. The overarching goal is to provide an overview of how implanted biosensors may improve the performance and outcomes of LVADs through continuous monitoring and closed-loop control.

Sex-based differences in left ventricular assist device clinical outcomes.

BACKGROUND: Heart failure (HF) continues to be a significant public health issue, posing a heightened risk of morbidity and mortality for both genders. Despite the widespread use of left ventricular assist device (LVAD), the influence of gender differences on clinical outcomes following implantation remains unclear. OBJECTIVES: We investigated the impact of gender differences on readmission rates and other outcomes following LVAD implantation in patients admitted with advanced HF. METHODS: We conducted a retrospective study of patients who underwent LVAD implantation for advanced HF between 2014 and 2020, using the Nationwide Readmissions Database. Our study cohort was divided into male and female patients. The primary outcome was 30-day readmission (30-dr), while secondary outcomes were inpatient mortality, length of stay (LOS), procedural complication rates, and periadmission rates. Multivariate linear, Cox, and logistic regression analyses were performed. RESULTS: During the study period, 11,492 patients with advanced HF who had LVAD placement were identified. Of these, 22% (n = 2532) were females and 78% (n = 8960) were males. The mean age was 53.9 ± 10.8 years for females and 56.3 ± 10.5 years for males (adjusted Wald test, p < 0.01). Readmissions were higher in females (21% vs. 17%, p = 0.02) when compared to males. Cox regression analysis showed higher readmission events (hazard ratio: 1.24, 95% confidence interval: 1.01-1.52, p = 0.03) in females when compared to males. Inpatient mortality, LOS, and most procedural complication rates were not statistically significantly different between the two groups (p > 0.05, all). CONCLUSION: Women experienced higher readmission rates and were more likely to be readmitted multiple times after LVAD implantation when compared to their male counterparts. However, there were no significant sex-based differences in inpatient mortality, LOS, and nearly all procedural complication rates. These findings suggest that female patients may require closer monitoring and targeted interventions to reduce readmission rates.

Comparison of in-hospital outcomes of ST-elevation myocardial infarction patients with cardiogenic shock receiving left ventricular mechanical circulatory support devices based on transfer status.

BACKGROUND: We aimed to compare outcomes in patients who receive on-site left ventricular mechanical support versus those transferred to other facilities for mechanical support in ST-elevation myocardial infarction (STEMI) patients with cardiogenic shock. METHODS: This retrospective study analyzed data from the 2016 to 2020 Nationwide Inpatient Sample (NIS) database. We identified patients with STEMI and cardiogenic shock who received Impella and LVAD placement during their hospital stay. They were divided into two groups: those with in-house (direct) placement and those transferred to higher-level medical centers. The primary goal was to compare mortality rates between these groups. RESULTS: During the study, 15,934 (75.2%) received in-house left ventricular support, while 5255 (24.8%) were transferred. Mean age (63 vs. 64 years) and female percentage (25 vs. 26%) were similar. The average time from admission to receiving LV support was 0.8 days for direct group versus 2.8 days for transfer group (p < 0.001). Transferred patients had a higher rate of prior heart failure (68 vs. 79%, p < 0.001) and peripheral vascular disease (10 vs. 14%, p < 0.001) but a lower rate of hypertension (23 vs. 17%, p = 0.003). There were no significant differences in other comorbidities. Primary outcome mortality did not significantly differ (44.9 vs. 44.2, p = 0.66). After multivariate analysis, transferred patients had higher rates of ECMO usage, acute kidney injury, renal replacement therapy, major bleeding, and ischemic stroke. Length of stay (8 vs. 15 days, p < 0.001) and total charges ($391,472 vs. $581,183, p < 0.001) were significantly higher in the transferred group. CONCLUSION: Among STEMI patients with cardiogenic shock, our study found no significant difference in mortality between patients transferred for and those with on-site LV support. Those transferred patients experienced more complications, longer length of stay, and increased hospital costs.

Temporarily Reversing Warfarin With Low-Dose 4-Factor Prothrombin Complex Concentrate in Left Ventricular Assist Device Patients Undergoing an Invasive Procedure.

BACKGROUND: American Association for Thoracic Surgery and The International Society for Heart and Lung Transplantation (AATS/ISHLT) guidelines recommend warfarin in patients with continuous-flow left ventricular assist devices (LVADs) to reduce the risk of device thrombosis and systemic embolization. Left ventricular assist device patients often undergo elective and emergent procedures that require interrupted anticoagulation. Data and experience vary on the optimal strategy to rapidly reverse warfarin in LVAD patients when an emergent procedure is planned. OBJECTIVE: The purpose of this study was to describe the use of 4-factor prothrombin complex concentrate (PCC4) for warfarin reversal in patients with LVADs undergoing elective and emergent procedures. METHODS: This retrospective, single-center, cohort review describes the use of PCC4 in patients with LVADs who require warfarin reversal for elective or emergent procedures. The primary outcome was a composite incidence of pump thrombosis, venous thromboembolism, and ischemic stroke within 30 days of PCC4 administration. RESULTS: In total, 14 patients received 17 administrations of PCC4. One patient received 3 administrations, and 1 other patient received 2 administrations during separate encounters. The median dose was 500 units or 6.6 units/kg (range = 4.2-14.1 units/kg). Of the PCC4 administrations, 82% (14/17) were for low bleed risk procedures and 76% (13/17) were for elective procedures. There were no cases of pump thrombosis, venous thromboembolism, or stroke within 30 days of the procedure. CONCLUSIONS AND RELEVANCE: Low-dose PCC4 appears to be a safe and effective temporary reversal strategy for patients with LVADs undergoing low-bleed risk elective procedures.

Effect of Preoperative Mitral Regurgitation on LVAD Outcomes in Patients with Elevated Pulmonary Vascular Resistance.

PURPOSE: In patients with end-stage heart failure who undergo left ventricular assist device (LVAD) implantation, higher pulmonary vascular resistance (PVR) is associated with higher right heart failure rates and ineligibility for heart transplant. Concomitant mitral regurgitation (MR) could potentially worsen pulmonary hemodynamics and lead to worse outcomes; however, its effects in this patient population have not been specifically examined. METHODS: Using an institutional database spanning November 2003 to August 2017, we retrospectively identified patients with elevated PVR who underwent LVAD implantation. Patients were stratified by concurrent MR: moderate/severe (PVR + MR) vs. mild/none (PVR - MR). Cumulative incidence functions and Fine-Gray competing risk regression were performed to assess the effect of MR on heart transplant rates and overall survival during index LVAD support. RESULTS: Of 644 LVAD recipients, 232 (171 HeartMate II, 59 HeartWare, 2 HeartMate III) had baseline PVR > 3 Woods units; of these, 124 (53%) were INTERMACS 1-2, and 133 (57%) had moderate/severe MR (≥ 3 +). Patients with PVR + MR had larger a baseline left ventricular end-diastolic diameter than patients with PVR - MR (87.9 ± 38.2 mm vs. 75.9 ± 38.0 mm; P = 0.02). Median clinical follow-up was 18.8 months (interquartile range: 4.7-36.4 months). Moderate/severe MR was associated with lower mortality rates during index LVAD support (adjusted hazard ratio 0.64, 95% CI 0.41-0.98; P = 0.045) and higher heart transplant rates (adjusted odds ratio 2.86, 95% CI 1.31-6.25; P = 0.009). No differences in stroke, gastrointestinal bleeding, or right heart failure rates were observed. CONCLUSIONS: Among LVAD recipients with elevated preoperative PVR, those with moderate/severe MR had better overall survival and higher transplant rates than those with mild/no MR. These hypothesis-generating findings could be explained by incremental LVAD benefits resulting from reduction of MR and better LV unloading in a subset of patients with larger ventricles at baseline. In patients with preoperative elevated PVR, MR severity may be a prognostic sign that can inform patient selection for end-stage heart failure therapy.

Patients with a high defibrillation threshold: Approaches to management.

Implantable cardioverter-defibrillators (ICDs) have revolutionized the prognosis for patients at elevated risk of ventricular tachyarrhythmias. For safety, defibrillation should be effective with a minimum of 10 J below the device's maximum energy. While modern ICDs rarely deliver ineffective shocks in primary prevention, the surge in managing severe heart failure patients has led to an increased number of patients with high defibrillation thresholds (DFTs). This article elucidates the potential causes of high DFT, including clinical factors, lead and device placement, the presence of a Left Ventricular Assist Device (LVAD), prolonged ventricular arrhythmias, shock vectors, waveform tilt, medications, and manufacturer-specific options. We also detail management strategies, highlighting alternative shock coil placements, practical recommendations, and case studies from our institution. Our management algorithm suggests addressing preventable causes, re-evaluating coil positions, considering non-invasive system modifications, upgrading to a higher-capacity device, and adding extra coil(s).

Single center outcomes after temporary mechanical circulatory assist device prior to Heartmate 3 implantation - a retrospective cohort study.

Objectives. Temporary mechanical circulatory support (TMCS) has become a component in the therapeutic strategy for treatment of cardiogenic shock as a bridge-to-decision. TMCS can facilitate recovery of cardiopulmonary function, end-organ function, and potentially reduce the surgical risk of left ventricular assist device (LVAD) implantation. Despite the improvements of hemodynamics and end-organ function, post-LVAD operative morbidity might be increased in these high-risk patients. The aim of the study was to compare outcomes after Heartmate 3 (HM3) implantation in patients with and without TMCS prior to HM3 implant. Methods. In this retrospective cohort study of all HM3 patients in the period between November 2015 and October 2021, patients with and without prior TMCS were compared. Patients' demographics, baseline clinical characteristics, laboratory tests, intraoperative variables, postoperative outcomes, and adverse events were collected from patient records. Results. The TMCS group showed an improvement in hemodynamics prior to LVAD implantation. Median TMCS duration was 19.5 (14-26) days. However, the TMCS group were more coagulopathic, had more wound infections, neurological complications, and more patients were on dialysis compared with patient without TMCS prior to HM3 implantation. Survival four years after HM3 implantation was 80 and 82% in the TMCS (N = 22) and non-TMCS group (N = 41), respectively. Conclusion. Patients on TMCS had an acceptable short and long-term survival and comparable to patients receiving HM3 without prior TMCS. However, they had a more complicated postoperative course.

Unplanned hospital readmissions following HeartMate 3 implantation: Readmission rates, causes, and impact on survival.

BACKGROUND: Hospital readmissions following left ventricular assist device (LVAD) remain a frequent comorbidity, associated with decreased quality of life and increased resources utilization. This study sought to determine causes, predictors, and impact on survival of hospitalizations during HeartMate 3 (HM3) support. METHODS: All patients implanted with HM3 between November 2014 to December 2019 at Columbia University Irving Medical Center were consecutively enrolled in the study. Demographics and clinical characteristics from the index admission and the first outpatient visit were collected and used to estimate 1-year and 900-day readmission-free survival and overall survival. Multivariable analysis was performed for subsequent readmissions. RESULTS: Of 182 patients who received a HM3 LVAD, 167 (92%) were discharged after index admission and experienced 407 unplanned readmissions over the median follow up of 727 (interquartile range (IQR): 410.5, 1124.5) days. One-year and 900-day mean cumulative number of all-cause unplanned readmissions was 0.43 (95%CI, 0.36, 0.51) and 1.13 (95%CI, 0.99, 1.29). The most frequent causes of rehospitalizations included major infections (29.3%), bleeding (13.2%), device-related (12.5%), volume overload (7.1%), and other (28%). One-year and 900-day survival free from all-cause readmission was 38% (95%CI, 31-46%) and 16.6% (95%CI, 10.3-24.4%). One-year and 900-day freedom from 2, 3, and ≥4 readmissions were 60.7%, 74%, 74.5% and 26.2%, 33.3%, 41.3%. One-year and 900-day survival were unaffected by the number of readmissions and remained >90%. Male sex, ischemic etiology, diabetes, lower serum creatinine, longer duration of index hospitalization, and a history of readmission between discharge and the first outpatient visit were associated with subsequent readmissions. CONCLUSIONS: Unplanned hospital readmissions after HM3 are common, with infections and bleeding accounting for the majority of readmissions. Irrespective of the number of readmissions, one-year survival remained unaffected.

Outcomes and quality of life in patients receiving durable left ventricular assist device with biventricular support.

BACKGROUND: Patients requiring biventricular support (BIVAD) face higher morbidity than those undergoing durable left ventricular assist device (LVAD) implantation alone. The goal of the current study was to evaluate quality of life (QOL) of patients with LVAD therapy in the modern era, stratified by use of biventricular support. METHODS: All patients undergoing LVAD at our center were reviewed between October 2017 and September 2021. Patients were stratified by perioperative use of BIVAD. Patients were administered a telephone survey consisting of the Kansas City Cardiomyopathy Questionnaire (KCCQ-12) as well as free-responses regarding satisfaction surrounding their operation. Outcomes included survival, KCCQ-12 metrics, and thematic analysis of free response questions. RESULTS: 92 patients were identified, of whom 26 (28%) received BIVAD support. BIVAD patients had more preoperative ECMO use (54% vs. 12%, p < 0.001) and lower INTERMACS scores (Category 1: 46% vs. 14%, p = 0.001). Three-year survival was 73.8% among LVAD-alone patients and 50.1% among BIVAD patients (log-rank p = 0.022). Median composite KCCQ-12 score was 78 (57-88). No differences in composite or any component scores were noted between groups. 76% of patients report they would be moderately or extremely like to go through surgery again if given repeat choice. The most common themes expressed were overall gratitude (24%) and disappointment with device-related restrictions (20%). CONCLUSIONS: Patients requiring BIVAD therapy have more advanced shock, longer associated hospital courses, and lower long-term survival. However, those that survive enjoy similar overall quality of life, and many endorse positive outlooks on their surgical course. Continued assessments of quality of life are important in providing patient-centered LVAD care.

Organ blood flow assessment with the ModulHeart cardiorenal support device.

BACKGROUND: ModulHeart (Puzzle Medical Devices Inc) is a novel percutaneous flow entrainment pump anchored in the descending aorta. The current study evaluates the hemodynamic effect of ModulHeart support and its impact on cerebral, myocardial, and renal blood flow. METHODS: ModulHeart was implanted in the descending aorta of four healthy calves. A ramp protocol (2000 RPM increments) was performed with the pump operating at five different speeds from 14 000 to 22 000 RPM. For each speed, pressures proximal and distal to the pump, and right heart catheterization measurements were recorded. Stable-isotope labeled microspheres were injected in the left ventricle to evaluate organ perfusion. RESULTS: Thermodilution cardiac output increased by 23% at 22 000 RPM. Greater pump speeds resulted in greater pump gradients, up to 10 mm Hg in mean arterial pressure at 22 000 RPM, without significant reduction of proximal perfusion pressures. Arterial pulse pressure remained stable at all speeds. ModulHeart was not associated with a reduction in cerebral or myocardial blood flow at any speed. Renal cortical and medullary blood flow increased by up to 50% and 40%, respectively. CONCLUSION: The ModulHeart device implanted in the descending aorta of healthy calves resulted in significant arterial pressure gradients and preserved pulse pressure. Greater pump speeds translated into greater increases in renal blood flow, with no decrease in cerebral or myocardial perfusion.

Ventricular assist devices and sleep-disordered breathing-A mechanical heart stimulating a sleepy brain.

Sleep-disordered breathing, including obstructive sleep apnea (OSA) and central sleep apnea (CSA), is common in severe heart failure (HF) patients. There is limited data on the effect of left ventricular assist devices (LVAD) on sleep apnea. We performed a retrospective review of 350 durable LVAD patients and found 5 with a history of pre- and post-LVAD sleep studies. All five patients had OSA, and three had concomitant CSA. We observed reduced apnea-hypopnea index following LVAD placement. This was due to a near abolishment of CSA in three mixed sleep apnea patients-as seen by a central apnea index improvement from an average of 25.9 ± 13.1 to 1.4 ± 2.5 events per hour (p = 0.063). LVAD placement was associated with an increase in thermodilution cardiac output from 2.7 ± 0.6 to 4.1 ± 1.1 L/min (p = 0.014). These findings support chemoreception physiology seen in patients with poor circulation and the effect of restoring this circulation with LVAD support.

Implantation of a fully magnetically levitated left ventricular assist device to a 3-year-old patient with body surface area of 0.57 m2.

Postoperative 3D thorax computed tomographic scan image of the patient.

Evaluation of enoxaparin for bridging of warfarin in outpatients with left ventricular assist devices (LVADs).

BACKGROUND: Patients with left ventricular assist devices (LVADs) require systemic anticoagulation. The use of enoxaparin for bridging to warfarin remains understudied in this population. METHODS: This single-center retrospective study was performed to characterize enoxaparin use and associated thrombotic and bleeding outcomes in adult outpatients with LVADs from January 2018 to July 2021. RESULTS: Fifty-four enoxaparin bridging events were evaluated in 49 patients. Most patients with HeartMate II (HM2) and HeartWare (HVAD) devices received enoxaparin dosed 1 mg/kg every 12 h. In patients with HeartMate 3 (HM3) devices, an equal number of patients received 0.5 mg/kg every 12 h and 1 mg/kg every 12 h, with a smaller subset receiving intermediate doses. The median duration of bridging was 6 days (4-8 [IQR]). One major bleeding event required discontinuation of enoxaparin and hospitalization in a patient with an HM3 device. Thrombotic events occurred in four patients with two incidents of pump thrombosis requiring pump exchange and two ischemic strokes. All thrombotic events occurred in patients with HVAD or HM2 devices. CONCLUSION: These results suggest that enoxaparin bridging in LVAD patients was well-tolerated with low bleeding and thrombotic rates, particularly with the HM3 device.