HeartMate Left Ventricular Assist Device Research Articles

Successful Thrombolytic Therapy in a Suspected Case of HeartMate 3 LVAD Thrombosis

IntroductionAlthough less common with the HeartMate 3 (HM3), pump thrombosis remains a life-threatening complication of durable left ventricular assist devices (LVAD). We present what we believe is the first case of suspected pump thrombosis in a patient with a HM3 LVAD that was successfully managed with tissue plasminogen activator (tPA).Case ReportA 22-year-old man who underwent HM3 implantation for end stage heart failure due to left ventricular non-compaction presented after experiencing two low flow alarms. His physical examination was notable for tachycardia at 125 beats per minute and an elevated Doppler mean blood pressure of 92 mm Hg. LVAD interrogation revealed low flows without power spikes (Figure 1A). Within 24 hours, he developed persistent hypotension requiring vasopressor support and multiple low flow alarms. Serial laboratory results were notable for rising LDH, peaking at 4,741 U/L and acute liver injury with AST 2,712 U/L, ALT 798 U/L and INR 5.2. Transthoracic echocardiography and computed tomography (CT) angiography did not reveal any obvious thrombus. Given this constellation of findings, pump thrombosis was suspected. Following multidisciplinary discussion, unfractionated heparin bolus and infusion were started. After an unremarkable head CT, heparin was stopped and systemic tPA was given at a dose of 5 mg over one minute followed by 10 mg over 10 minutes due to ongoing liver dysfunction. Heparin was resumed after PTT returned to therapeutic range. Immediately post tPA infusion, his LVAD flows improved from 2.3 L/min to 4.1 L/min (Figure 1B). Vasopressor support was quickly weaned. LDH, creatinine, and liver enzymes improved over the following days. Warfarin was resumed on day 14 of admission. He was discharged on aspirin, clopidogrel and warfarin.SummaryThrombolytics may be a potential therapeutic option in select cases of HM 3 pump thrombosis. Further research is warranted to delineate LVAD parameters that facilitate early recognition of pump thrombosis and successful medical management. Although less common with the HeartMate 3 (HM3), pump thrombosis remains a life-threatening complication of durable left ventricular assist devices (LVAD). We present what we believe is the first case of suspected pump thrombosis in a patient with a HM3 LVAD that was successfully managed with tissue plasminogen activator (tPA). A 22-year-old man who underwent HM3 implantation for end stage heart failure due to left ventricular non-compaction presented after experiencing two low flow alarms. His physical examination was notable for tachycardia at 125 beats per minute and an elevated Doppler mean blood pressure of 92 mm Hg. LVAD interrogation revealed low flows without power spikes (Figure 1A). Within 24 hours, he developed persistent hypotension requiring vasopressor support and multiple low flow alarms. Serial laboratory results were notable for rising LDH, peaking at 4,741 U/L and acute liver injury with AST 2,712 U/L, ALT 798 U/L and INR 5.2. Transthoracic echocardiography and computed tomography (CT) angiography did not reveal any obvious thrombus. Given this constellation of findings, pump thrombosis was suspected. Following multidisciplinary discussion, unfractionated heparin bolus and infusion were started. After an unremarkable head CT, heparin was stopped and systemic tPA was given at a dose of 5 mg over one minute followed by 10 mg over 10 minutes due to ongoing liver dysfunction. Heparin was resumed after PTT returned to therapeutic range. Immediately post tPA infusion, his LVAD flows improved from 2.3 L/min to 4.1 L/min (Figure 1B). Vasopressor support was quickly weaned. LDH, creatinine, and liver enzymes improved over the following days. Warfarin was resumed on day 14 of admission. He was discharged on aspirin, clopidogrel and warfarin. Thrombolytics may be a potential therapeutic option in select cases of HM 3 pump thrombosis. Further research is warranted to delineate LVAD parameters that facilitate early recognition of pump thrombosis and successful medical management.

Sex-Based Differences in Survival and Readmissions After Insertion of HeartMate3 (HM3) Left Ventricular Assist Device

<h3>Purpose</h3> Left ventricular assist device (LVAD) technology remains underutilized among women with advanced heart failure, likely biased by concerns for increased risk in this population. We investigated survival and cumulative incidence of readmission in LVAD patients separated by sex. <h3>Methods</h3> We retrospectively reviewed all patients who underwent HM3 LVAD implantation from 11/26/14 to 12/4/19 at a single large-volume center. All unplanned readmissions up to 900-days of follow up were analyzed. Readmissions were categorized based on INTERMACS criteria into: major bleeding, infection, arrhythmia, volume overload, device-related complications and other causes. Survival was evaluated by KM method. Incidence of all-cause readmission was evaluated using mean cumulative function method. <h3>Results</h3> Of 182 HM3 pts, 30 were women and 152 were men. Relative to women, men were more commonly white (65.1% vs 30.0%, p=0.0003), had ischemic cardiomyopathy (42.8% vs 16.7%, p=0.007) and higher baseline serum creatinine (1.45(1.2-1.8) vs 1.12(0.81-1.4)mg/dL, p<0.0001). Overall survival during index admission and at 900-days was similar (women vs men: 93.3% vs 94.1%, p=0.9; 83.3% vs 83.0%, p=0.9, respectively (<b>Figure 1A</b>). Cumulative incidence of all-cause readmissions was similar (p=0.55). Readmissions separated by etiology were also similar, except women had a greater incidence of device-related readmissions (19.7% vs 11.3%, p=0.05) (<b>Figure 1B</b>). The most common reason among device-related readmissions was low flow alarm. Median time to first readmission (p=0.56) and length of stay during index admission (p=0.66) was similar. <h3>Conclusion</h3> Women have similar survival during index admission and at 900-days of follow up. Cumulative incidence of all-cause readmission did not differ by sex, however women were more commonly admitted with device-related complications. Future investigations into the sex related LVAD outcomes is critical to avoid this treatment disparity.

Outcomes of Patients Supported with Heartmate Three Left Ventricular Assist Device for More Than Two Years

<h3>Purpose</h3> Left ventricular assist devices (LVAD) improve two-year survival and quality of life in patients with advanced heart failure. Following the MOMENTUM 3 study, Heartmate 3 (HM3) LVAD is the only device approved in the US and Europe. Data for event-free survival beyond two years on HM 3 is limited. The aim of this study was to assess the adverse event profile in patients who survive more than 2 years on support. <h3>Methods</h3> We retrospectively reviewed all patients who received a HM3 LVAD at our center between 5/8/2015-10/29/2018. Patients who were alive two years following LVAD implant and were still on LVAD support were included in the study and followed for an additional two years. Patient outcomes including hospitalizations over the subsequent two years of follow-up were recorded (between year 2 and 4). Event percent per year (EPPY) was calculated for each of these outcomes. <h3>Results</h3> 127 patients received an LVAD during the study period with a 2 year survival rate of 85.1%. Within the first 2 years, 19 patients died, 39 patients were transplanted, and 13 transferred institutions or were lost to follow up. 56 patients remained on support and were included in this analysis and followed for an additional 2 years. The average age was 61 ± 14, 81% were male. Of those 56 patients, 50 patients were alive on support 4 years after LVAD implant (89%) (3 died and 3 patients underwent transplant). Between years 2 and 4 years from HM 3 implant, 51% were hospitalized. The most common causes of hospitalization were ADHF (0.142 EPPY), drive line infection (DLI) (.0268 EPPY) and GI bleed (0.0089 EPPY). <h3>Conclusion</h3> In patients surviving 2 years on HM3 LVAD support the overall survival rate for additional 2 years is excellent. However, half of the patients will be hospitalized during long-term support, highlighting the need for more studies of medical management to prevent complications in this cohort of patients.

Development and Validation of a Personalized Risk Score for Prediction of Patient-Specific Clinical Experiences with HeartMate 3 LVAD Implantation: An Analysis from the MOMENTUM 3 Trial Portfolio

<h3>Purpose</h3> Although clinical trials inform on efficacy of left ventricular assist device (LVAD) therapy, individualized risk assessments for outcome prediction are important in guiding implementation of such treatment. In this analysis based on the MOMENTUM 3 trial portfolio (studies sponsored by Abbott), we seek to develop and validate patient-specific risk scores to facilitate the evaluation of candidates for HeartMate 3 (HM3) LVAD implantation. <h3>Methods</h3> The MOMENTUM 3 trial portfolio includes 2200 patients that underwent HM3 LVAD implantation in the pivotal trial and Continued Access Protocol (CAP) study, between 2014-2018. Patients were followed for 2 years, and the primary results were presented at ISHLT 2021 and published in <i>Eur J Heart Fail</i>. 2021;23:1392-1400. In this analysis, we shall randomly assign all enrolled patients implanted with the HM3 LVAD to a Derivation Cohort or an internal Validation Cohort. The Derivation Cohort will be used to develop multivariate regression models incorporating common, pre-implant patient parameters that are typically assessed when an informed decision is established. Calculation of the risk scores will be based on the parameter estimates of the final derived models. Receiver operating characteristic curve analysis will be used to evaluate the discriminatory ability of each risk score. The ability of the risk scores to predict outcomes after HM3 LVAD implantation will be tested independently in the Validation Cohort (results expected by February 2022). To avoid bias in the development of the scores, the Validation Cohort will only be analyzed after the risk models are derived. The risk scores will include estimates (and range of individual outcomes) for endpoints including short and long-term survival, hospitalization burden, quality of life, hemocompatibility and non-hemocompatibility related adverse events. <h3>Endpoints</h3> The scientific discovery and validation of personalized risk scores will inform clinicians on expectations of individualized outcomes through the clinical journey following HM3 LVAD implantation. Such risk scores and individualized estimates for outcomes will facilitate enhanced decision-making and guide communication among clinicians and patients when considering LVAD therapy in advanced heart failure.

Heart Mate 3 Pump Thrombosis After Ventricular Tachycardia Ablation: Pushing the Boundaries of Hemocompatibility

<h3>Introduction</h3> The risk for pump thrombosis (PT) following ventricular tachycardia (VT) ablation in HeartMate II and HeartWare HVAD left ventricular assist devices (LVADs) has been described previously; however, it is unknown whether Heart Mate 3 (HM3) LVADs are also at increased risk of PT following VT ablation. <h3>Case Report</h3> A 51-year-old male with non-ischemic cardiomyopathy status post HM3 LVAD as destination therapy, VT on mexiletine and quinidine with previous VT ablation, and amiodarone-induced thyrotoxicosis presented to the emergency room in VT storm after multiple defibrillator shocks. He underwent successful endocardial/epicardial VT ablation of seven VT morphologies, ethanol ablation of the coronary sinus branch, as well as coil embolization of two left circumflex branches that fed the culprit territory. Target ACT was achieved throughout the procedure and he was bridged to warfarin with a therapeutic INR upon discharge. Two weeks later, he presented with low flow LVAD alarms, a subtherapeutic INR, and an elevated lactate dehydrogenase concerning for PT. Despite volume resuscitation and pressors, he required initiation of venoarterial extracorporeal membrane oxygenation (VA-ECMO), intra-aortic balloon pump, and underwent a LV outflow tract aortogram. Thrombus was noted in the LVAD outflow graft and the LVAD flow was 0 liters per minute. Thrombolytics were not given due to the patient's tenuous status and need for emergent pump exchange, so decision was made to turn off the LVAD to prevent a cardioembolic event while he was supported by VA-ECMO. Transthoracic echocardiogram confirmed PT with a large thrombus extending out of the inflow cannula. The patient was deemed not to be a surgical candidate given a high operative mortality after worsening shock, liver failure, and bacteremia. His family proceeded with comfort care and support was withdrawn. <h3>Summary</h3> While PT is rare with HM3 LVADs even with lower intensity anticoagulation, there may be a higher risk of PT after VT ablation.

Single-Center Analysis of Patients with HeartMate 3 LVAD External Outflow Graft Obstruction

<h3>Purpose</h3> There is limited published data regarding external outflow graft obstruction (EOGO) of the Heartmate 3 (HM3) left ventricular assist device (LVAD) (Abbott Labs, Chicago, IL) and its clinical consequences despite the suspicion that it is a commonly observed complication in practice. <h3>Methods</h3> The cohort included adults with HM3 LVADs at a single center. Chart review was completed to assess baseline characteristics, serial right heart catheterization and echocardiographic data while on support, as well as if there was suspicion or confirmation of EOGO including symptoms, CT of the LVAD, and pathology of the explanted device. Hospital readmissions for obstruction concerns and upgrade of status on the heart transplant list while on support were recorded. <h3>Results</h3> The cohort consisted of 24 patients with a mean age of 55 +/- 13, 25% were classified as destination therapy, and 75% had nonischemic cardiomyopathy. 12/24 patients had suspected and/or confirmed EOGO, of which 7/12 were symptomatic. The other 5/12 were discovered at the time of transplant (Table). 3/12 patients were readmitted for concerns of EOGO and 5/12 required status upgrade on the transplant waitlist. CT findings and pathology of the explanted LVADs showed compressive material between the outflow graft and the bend relief (Figure). <h3>Conclusion</h3> Although EOGO of HM3 LVADs is commonly seen in clinical practice, it has been under reported in the literature. Our study shows it is a common finding with potential of serious complications. A large multicenter study of EOGO is needed to completely understand the full scope of EOGO, and its clinical impact on patient care.

Analysis Paralysis: Transition to HeartMate 3 Left Ventricular Assist Device Despite Multiple Complications from COVID-19

IntroductionWe present a case of a 39 year old male with nonischemic cardiomyopathy who was successfully bridged to HeartMate3 Left Ventricular Assist Device (LVAD) despite multiple life threatening complications secondary to Covid-19.Case Report39-year-old male with past medical history notable for tobacco abuse and recently diagnosed non-ischemic cardiomyopathy presented to our institution with NYHA Class IV symptoms and was found to be in cardiogenic shock. On admission Covid-19 PCR was negative. He initially responded to the initiation of inotropic support and aggressive diuresis with normalization of his end-organ function and improvement in his symptoms over three days. He suddenly experienced rapid hemodynamic decline necessitating escalation of inotropic and mechanical circulatory support with VA ECMO and Impella 5.5. On that day, his wife felt unwell and was found to be positive for Covid-19. The patient's Covid-19 PCR was repeated and also positive. He underwent treatment with Regeneron. His hospital course was further complicated by multiple sequelae of Covid-19 including pneumonia, acute renal failure necessitating hemodialysis (HD), and Guillain Barre Syndrome (GBS) presenting with bilateral ascending paralysis extending to his hip flexors, improved with intravenous immune globulin (IVIG) therapy.Over a period of two weeks, he demonstrated improvement and was weaned from VA ECMO to Impella 5.5. Unfortunately, he was unable to tolerate weaning the Impella 5.5. He was aggressively rehabilitated. After extensive multidisciplinary discussion, LVAD implantation was recommended to the patient. Following insertion of a HeartMate3 LVAD, the patient demonstrated renal recovery and ongoing improvement in physical ability. He was discharged to an acute rehabilitation facility and was subsequently discharged home. He will be monitored for listing for cardiac transplantation pending abstinence from tobacco use.SummaryCovid-19 can present with multiple life threatening complications that can add novel challenges to the management of patients with stage D cardiomyopathy. Despite complications of acute renal failure and paralysis secondary to GBS from Covid-19, our patient was successfully supported with temporary mechanical circulatory support, aggressively rehabilitated, and transitioned to a durable HeartMate 3 LVAD.

CT Derived Three Dimensional Modeling to Facilitate Minimally Invasive HVAD to HeartMate3 Left Ventricular Assist Device Exchange

<h3>Introduction</h3> The optimal surgical technique for HVAD to HeartMate 3 left ventricular assist device (LVAD) exchange will be patient dependent. We report a successful minimally invasive approach. <h3>Case Report</h3> Case: A 33-year-old woman with Adriamycin induced cardiomyopathy status post destination therapy HVAD in 2006 developed progressive alarms. Imaging revealed a large left ventricular (LV) thrombus attached to the inflow cannula. An elective HVAD to HeartMate 3 exchange was considered. Pre-operative planning: CT imaging was used to generate a three dimensional (3D) model of the heart and HVAD (A). To aid in planning both new device placement and the anastomosis between the HVAD and HeartMate 3 outflow grafts, a 3D model was generated (B). Surgical description: A left thoracotomy and 5th rib resection was used to access the HVAD and LV apex (C). The femoral vessels were cannulated for cardiopulmonary bypass and the heart was minimally manipulated. The HVAD pump, apical cuff, and exposed driveline were removed and LV clot evacuated. The HeartMate 3 apical cuff was secured to the LV apex and the pump placed in standard position (D). The HeartMate 3 (14mm) outflow graft was anastomosed to the retained HVAD (10mm) outflow graft by beveling the HVAD outflow graft (E, F). The HeartMate 3 driveline was then tunneled out of the left upper abdominal quadrant using a double tunnel technique. The thoracotomy was then closed in a standard fashion. <h3>Summary</h3> Outcome: The total bypass time was 1 hour and 20 minutes. She arrived to the intensive care unit on low dose epinephrine and vasopressin, which were rapidly weaned off. She required a total of 2 packed red blood cell transfusions. She was extubated on post-operative day 3 with normal hemodynamics and intact end organ function. She was eventually discharged in stable condition. 3D modeling was invaluable in preprocedural planning and final outcomes.

Slow It Down: A Case Report Of Microangiopathic Hemolytic Anemia In A Heartmate III Patient

<h3>Introduction</h3> Incidence of hemolysis in left ventricular assist devices (LVADs) is reported from 13-18%, but with HeartMate 3 (HM3) LVAD has been decreased to <1%. Typically, hemolysis is associated with LVAD thrombosis with subsequent decreased survival rate at 1 year (38.9% vs. 89.3%). We present a case of microangiopathic hemolytic anemia (MAHA), not related to pump thrombosis in a recent implanted HM3 LVAD patient which resolved by decreasing LVAD speed. <h3>Case Report</h3> A 44 year-old man with status post LVAD HM3 4 months prior complicated with right ventricular (RV) failure, pulmonary hypertension and CKD Stage III was admitted for mixed vasodilatory and cardiogenic shock. Patient required dual inotropes, vasopressors and temporary renal replacement therapy in an effort to stabilize him and continue his evaluation for heart and kidney transplant. Meanwhile, patient developed acute, severe thrombocytopenia (platelet count of 26K) and mild anemia. Disseminated intravascular coagulation was unlikely (normal fibrinogen level). Heparin-induced thrombosis (HIT) antibody testing was non-reactive. No active sepsis. There were no power spikes or suspected LVAD thrombosis (Table 1). Intrinsic bone marrow disease was thought to be unlikely. LDH was elevated and haptoglobin level undetectable (Table 2), blood smear showed schistocytes, raising suspicious for MAHA, therefore LVAD speed was decreased to 5100 RPM to diminish red blood cell (RBC) fragmentation and maintained in systemic unfractionated heparin infusion. This resulted in recovery of platelets and hemolysis parameters (Table 2). Ultimately, patient underwent dual organ transplantation without complications. <h3>Conclusions</h3> Per our knowledge, this is the first case reported of MAHA in a LVAD HM3 patient, not related to pump thrombosis that resolves with decrease in LVAD speed. MAHA is caused by mechanical injury of RBCs. The effective treatment in this scenario was to decrease the speed of the LVAD, hypothetically to decrease excessive shear in circulation. Further research should be done to delineate efficacy of reducing LVAD speed in these patients.

Home-based Exercise Rehabilitation Using Remote Monitoring In Left Ventricular Assist Device Recipients: Pilot Data From The Prospective Move-lvad Study

Introduction Home-based exercise rehabilitation (HER), using a wearable activity monitor and smartphone app, may be an alternative to supervised cardiac rehabilitation in new left ventricular assist device (LVAD) recipients. The aim of the MOVE-LVAD study is to provide data on the feasibility, safety, and efficacy of HER. Hypothesis: We hypothesize that HER, compared to usual care (UC), is safe and associated with improved activity levels. Methods MOVE-LVAD is a randomized, controlled study conducted at a single center. We aim to prospectively enroll 30 new HeartMate 3 (HM3) LVAD recipients. Subjects in both the HER and UC groups wear an activity watch continuously to monitor daily steps. Patients in the HER group also use a smartphone app to rate perceived exertion on the Borg scale and complete video calls with an exercise physiologist. Daily steps and Borg rating are used to titrate exercise prescriptions in the HER group. Endpoints include effects of HER, compared to UC, on functional status and healthcare utilization. Results We provide functional and outcome data on the first ten patients enrolled in MOVE-LVAD through April, 2021. Four patients (mean age 66 years) were randomized to HER and six patients (mean age 55 years) to UC. Average daily steps at baseline and during follow-up in the two groups are shown in the Figure. At baseline, median daily steps were similar in the HER and UC groups (535 [IQR 355, 1319] vs. 572 [IQR 217, 1812], respectively; p=1.00). In the HER group, median daily steps were significantly increased from baseline to 8556 (IQR 5081, 12030) at 4-months (p=0.05). In contrast, in the UC group, median daily steps were not significantly different between baseline and 4-months (1078 [IQR 962, 1193] p=0.52). There were no major adverse events associated with HER. One patient in the UC group was rehospitalized for non-VAD infection. Conclusions Our preliminary data from the MOVE-LVAD study suggest that HER using remote monitoring is feasible, safe, and may lead to improved activity levels in newly implanted HM3 LVAD patients. Home-based exercise rehabilitation (HER), using a wearable activity monitor and smartphone app, may be an alternative to supervised cardiac rehabilitation in new left ventricular assist device (LVAD) recipients. The aim of the MOVE-LVAD study is to provide data on the feasibility, safety, and efficacy of HER. Hypothesis: We hypothesize that HER, compared to usual care (UC), is safe and associated with improved activity levels. MOVE-LVAD is a randomized, controlled study conducted at a single center. We aim to prospectively enroll 30 new HeartMate 3 (HM3) LVAD recipients. Subjects in both the HER and UC groups wear an activity watch continuously to monitor daily steps. Patients in the HER group also use a smartphone app to rate perceived exertion on the Borg scale and complete video calls with an exercise physiologist. Daily steps and Borg rating are used to titrate exercise prescriptions in the HER group. Endpoints include effects of HER, compared to UC, on functional status and healthcare utilization. We provide functional and outcome data on the first ten patients enrolled in MOVE-LVAD through April, 2021. Four patients (mean age 66 years) were randomized to HER and six patients (mean age 55 years) to UC. Average daily steps at baseline and during follow-up in the two groups are shown in the Figure. At baseline, median daily steps were similar in the HER and UC groups (535 [IQR 355, 1319] vs. 572 [IQR 217, 1812], respectively; p=1.00). In the HER group, median daily steps were significantly increased from baseline to 8556 (IQR 5081, 12030) at 4-months (p=0.05). In contrast, in the UC group, median daily steps were not significantly different between baseline and 4-months (1078 [IQR 962, 1193] p=0.52). There were no major adverse events associated with HER. One patient in the UC group was rehospitalized for non-VAD infection. Our preliminary data from the MOVE-LVAD study suggest that HER using remote monitoring is feasible, safe, and may lead to improved activity levels in newly implanted HM3 LVAD patients.

Abstract 11755: Adverse Events of Third Generation Left Ventricular Assist Devices: Insights From the Manufacturer and User Facility Device Experience Database

Background: Left ventricular assist devices (LVAD) are used frequently to treat end-stage heart failure. The HeartMate 3 (HM-3), the newest LVAD, has limited data on complications. We analyzed the post-marketing surveillance data from the Manufacturer and User Facility Device Experience (MAUDE) database to evaluate complications from the HM-3. Methods: We queried the MAUDE database for device event reports of the HM-3 LVAD from 1/1/2017 to 12/31/2019. We screened event reports for completeness, stratified complications into the device and patient effects, and used descriptive analyses on the compiled reported complications. Results: In this time period, 3,867 device reports met the search criteria, of which 961 identifiable device-specific complications were reported. The most common device events reported were infusion flow disruptions (21.0%), halted pump (9.2%), and material deformation (8.4%). Additionally, 5,676 events affecting patients were also reported in this period. Not counting death, blood loss (21.8%), infection (17.8%), and thrombus (3.3%) were the most commonly reported clinical events. Lastly, 535 deaths were reported, stemming from cerebral vascular accidents (9.7%) and hemorrhage (6.7%). Device events, patient events, with device and patient events associated with death are represented in Figure 1 . Conclusion: Findings from the MAUDE database provide insight into complications and risks of the HM-3 LVAD. Addressing the complications and understanding the risk may improve clinical outcomes for patients with refractory heart failure. Figures 1A, 1B, 1C, 1D

Outcomes in patients with smaller body surface area after HeartMate 3 left ventricular assist device implantation.

Due to anatomic and physiologic concerns, prior generations of the left ventricular assist devices (LVAD) have frequently been denied to patients with small body size. However, outcomes in patients with small body surface area (BSA) following HeartMate 3 (HM3) LVAD implantation remain relatively unknown. A cohort of 220 patients implanted at a single center was divided into two groups: BSA ≤1.8 m2 (small BSA, n=37) and BSA >1.8 m2 (large BSA, n=183). We investigated baseline characteristics and clinical outcomes including survival and incidence of adverse events. Small BSA patients were older (60 vs. 57years), more likely female (60% vs. 20%), had a lower body mass index (24 vs. 32kg/m2 ), lower incidence of diabetes (32% vs. 51%), history of stroke (5% vs. 19%), and left ventricular thrombus (0% vs. 11%). They had smaller left ventricular end diastolic diameter (64.8 vs. 69.3mm). Pump speed and pump flows at discharge were lower in the small BSA group. Survival at 1year and 2years was 86% versus 87% and 86% versus 79% for small versus large BSA groups (p=0.408), respectively. The rates of adverse events were similar between groups and there were no cases of confirmed pump thrombosis. The incidence of readmissions for low flow alarms was higher in the small BSA group (0.55 vs. 0.24 EPPY). These findings demonstrate comparable outcomes in patients with small body size and suggest that this parameter should not be an exclusion criterion on patients who are otherwise candidates for HM3 LVAD implantation.

Validation of mitral regurgitation reversibility in patients with HeartMate 3 LVAD implantation.

The resolution of functional mitral valve regurgitation (MR) in patients awaiting left ventricular assist device (LVAD) implantation is discussed controversially. The present study analyzed MR and echocardiographic parameters of the third-generation LVAD HeartMate 3 (HM3) over 3years. Of 135 LVAD patients (with severe MR, n=33; with none, mild, or moderate MR, n=102), data of transthoracic echocardiography were included preoperatively to LVAD implantation, up to 1month postoperatively, and at 1, 2, and 3years after LVAD implantation. Demographic data and clinical characteristics were collected. Severe MR was reduced immediately after LVAD implantation in all patients. The echocardiographic parameters left ventricular end-diastolic diameter (P<.001), right ventricular end-diastolic diameter (P<.001), tricuspid annular plane systolic excursion (P<.001), and estimated pulmonary artery pressure (P<.001) decreased after HM3 implantation independently from the grade of MR prior to implantation and remained low during the 2years follow-up period. Following LVAD implantation, right heart failure, ventricular arrhythmias, ischemic stroke as well as pump thrombosis and bleeding events were comparable between the groups. The incidences of death and cardiac death did not differ between the patient groups. Furthermore, the Kaplan-Meier analysis showed that survival was comparable between the groups (P=.073). HM3 implantation decreases preoperative severe MR immediately after LVAD implantation. This effect is long-lasting in most patients and reinforces the LVAD implantation without MR surgery. The complication rates and survival were comparable between patients with and without severe MR.

Increased pulsatility index is associated with adverse outcomes in left ventricular assist device recipients.

AimsRecipients of left ventricular assist devices (LVAD) are exposed to increased risk of adverse clinical events. One of the potential contributing factors is non‐pulsatile flow generated by LVAD. We evaluated the association of flow patterns in carotid arteries and of increased arterial stiffness with death and cerebrovascular events in LVAD recipients.Methods and resultsWe analysed data from 83 patients [mean age 54 ± 15 years; 12 women; HeartMate II (HMII), n = 34; HeartMate 3 (HM3), n = 49]. Pulsatile and resistive indexes, atherosclerotic changes in carotid arteries (measured by duplex ultrasound), and arterial stiffness [measured by Endo‐PAT 2000 as the augmentation index standardized for heart rate (AI@75)] were evaluated 3 and 6 months after LVAD implantation. Sixteen patients died during follow‐up (27.3 months; interquartile range 15.7–44.3). After adjusting for the main variables examined, the pulsatility index measured at 3 months was positively associated with increased hazard ratios (HR) for death and cerebrovascular events [HR 9.8, 95% confidence interval (CI) 1.62–59.42], with HR increasing after adding AI@75 to the model (HR 18.8, 95% CI 2.44–145.50). In HM3 recipients, HR was significantly lower than in HMII recipients (HR 0.31, 95% CI 0.11–0.91), but the significance disappeared after adding AI@75 to the model (HR 0.33, 95% CI 0.09–1.18).ConclusionsThe risk of death and cerebrovascular events in LVAD recipients is associated with increased pulsatility index in carotid arteries and potentiated by increased arterial stiffness. The same risk is attenuated by HM3 LVAD implantation, but this effect is weakened by increased arterial stiffness.

Left Ventricular Flow Dynamics with the HeartMate3 Left Ventricular Assist Device: Effect of Inflow Cannula Position and Speed Modulation.

Improper left ventricular assist device (LVAD) inflow cannula (IC) positioning creates areas of stasis and low pulsatility that predispose thromboembolism, but may be mitigated with LVAD speed modulation. A mock loop study was performed to assess the sensitivity of left ventricle (LV) flow architecture to IC position and speed modulation during HeartMate3 support. System pressure, flow, and the time-resolved velocity field were measured within a transparent silicone LV for three IC angles and three IC insertion depths at matched levels of cardiac function and LVAD speed. Inflow cannula angulation towards the septum increased the resistance to LVAD flow as well as increasing the size and energy of the counter-clockwise (CCW) vortex. Apical velocity was reduced compared to IC angulation towards the mitral valve, but regional pulsatility was maintained across all angles and LVAD speeds. Increased IC protrusion decreased LVAD flow resistance, increasing velocity within the IC but reducing flow and pulsatility in the adjacent apical region. Increasing LVAD flow resistance improves aortic valve opening and strengthens the CCW vortex which directs inflow towards the septum, producing higher blood residence time and shear activation potential. Despite this impact on flow architecture, pulsatility reduction with increased LVAD speed was minimal with the HeartMate3 speed modulation feature.

Primary results of long-term outcomes in the MOMENTUM 3 pivotal trial and continued access protocol study phase: a study of 2200 HeartMate 3 left ventricular assist device implants.

AimThe MOMENTUM 3 pivotal trial established superiority of the HeartMate 3 (HM3) left ventricular assist device (LVAD), a fully magnetically levitated centrifugal‐flow pump, over the HeartMate II axial‐flow pump. We now evaluate HM3 LVAD outcomes in a single‐arm prospective continuous access protocol (CAP) post‐pivotal trial study.Methods and resultsWe enrolled 2200 HM3 implanted patients (515 pivotal trial and 1685 CAP patients) and compared outcomes including survival free of disabling stroke or reoperation to replace or remove a malfunctioning device (primary composite endpoint), overall survival and major adverse events at 2 years. The 2‐year primary endpoint [76.7% vs. 74.8%; adjusted hazard ratio (HR) 0.87, 95% confidence interval (CI) 0.71–1.08, P = 0.21] and overall survival (81.2% vs. 79.0%) were similar among CAP and pivotal cohorts despite sicker patients (more intra‐aortic balloon pump use and INTERMACS profile 1) in CAP who were more often intended for destination therapy. Survival was similar between the CAP and pivotal trial in transplant ineligible patients (79.1% vs. 76.7%; adjusted HR 0.89, 95% CI 0.68–1.16, P = 0.38). In a pooled analysis, the 2‐year primary endpoint was similar between INTERMACS profiles 1–2 (‘unstable’ advanced heart failure), profile 3 (‘stable’ on inotropic therapy), and profiles 4–7 (‘stable’ ambulatory advanced heart failure) (75.7% vs. 77.6% vs. 72.9%, respectively). The net burden of adverse events was lower in CAP (adjusted rate ratio 0.93, 95% CI 0.88–0.98, P = 0.006), with consequent decrease in hospitalization.ConclusionsThe primary results of accumulating HM3 LVAD experience suggest a lower adverse event burden and similar survival compared to the pivotal MOMENTUM 3 trial.

Less Invasive HeartMate 3 Left Ventricular Assist Device Implantation under Deep Hypothermic Circulatory Arrest for Severely Calcified Aorta

Introduction Left ventricular assist devices (LVADs) such as the HeartMate 3 (HM3) are becoming more frequently implanted in those with end-stage heart failure. We present one such patient with prior sternotomies and severely calcified ascending aorta in whom we planned a less invasive LVAD implantation via redo hemi-sternotomy and left thoracotomy with short-term deep hypothermic circulatory arrest (DHCA) to avoid cross-clamping of the aorta. Case Report A 70 year old male with history of two prior cardiac surgeries and heart failure presented in cardiogenic shock requiring temporary mechanical support with Impella CP. He continued to require increasing doses of inotropes and pressors; therefore, he was approved for high risk LVAD placement. A preoperative 4D CT scan revealed severely calcified ascending aorta with only a small area of focal sparing. First, a left anterior thoracotomy in the fifth intercostal space and redo upper hemi-sternotomy was performed. The LVAD outflow graft was positioned through the thoracotomy and brought up to the ascending aorta via the right pleural space, which was opened from the hemi-sternotomy. After initiation of cardiopulmonary bypass, the patient was cooled to 28°C with selective antegrade cerebral perfusion via the right axillary artery and systemic perfusion was temporarily arrested. DHCA was achieved. The LVAD outflow graft was then anastomosed to the aorta after which circulation was restarted and the patient rewarmed. The HM3 LVAD was then implanted in the LV apex and the rest of the operation was completed successfully. Summary Placing an LVAD via thoracotomy has theoretical advantages over a median sternotomy. Surgical trauma is minimized leading to less postoperative bleeding, improved maintenance of the chest stability, earlier recovery, and less cost. Additionally, there might be a reduction in post-operative right heart failure since the pericardium remains intact. Data from the LATERAL study and ELEVATE registry support the safety of this approach. While data support the safety of DHCA in other aortic arch procedures, there are only two case reports of DHCA for LVAD implantation. Our unique case validates the safety of LVAD implantation via thoracotomy and highlights the use of preoperative CT as well as DHCA in placement of an LVAD in a patient with severely calcified ascending aorta.

Aortic Insufficiency Following Heartmate 3 Implant in Patients on Temporary Mechanical Circulatory Support

<h3>Purpose</h3> Aortic insufficiency (AI) following continuous flow left ventricular assist device (LVAD) implant is a well-established complication associated with poor outcomes. Detailed assessment of aortic valve (AV) prior to LVAD implant may be challenging in critically ill patients supported with extracorporeal membranous oxygenation (ECMO) and/or Impella. This study aimed to investigate the risk of AI in HeartMate3 (HM3) recipients bridged from ECMO and/or Impella. <h3>Methods</h3> A single center retrospective review was conducted on all INTERMACS Stage 1 and 2 patients who were bridged to HM3 LVAD between 11/2014 and 10/2019 with intra-aortic balloon pump (IABP) alone or with ECMO/Impella. Patients were excluded for both repaired and unrepaired more than trace AI at the time of implant, post-LVAD endocarditis, or death during the index hospitalization. Echocardiograms at 1, 3, 6, and 12 months post-implant were reviewed and assessed for AI severity based on jet width and/or vena contracta. <h3>Results</h3> 17 patients bridged with ECMO/Impella and 50 patients bridged with IABP alone were enrolled to the study. The ECMO/Impella cohort consisted of 10 patients with ECMO and IABP, 2 with ECMO and Impella, 2 with ECMO alone, and 3 with Impella alone. There was no significant difference in age, sex, body mass index, strategy, and etiology of cardiomyopathy between two groups. Proportion of patients without AV opening at 1-month post implant were not significantly different (ECMO/Impella 47% vs. IABP 64%, p=0.26). Cumulative incidence of greater than mild AI during the first-year follow-up was 44% in Impella/ECMO group, compared to 16% in IABP cohort (p=0.038, Figure 1). <h3>Conclusion</h3> A higher incidence of AI was observed following HM3 LVAD implant in patients bridged with ECMO or Impella support than those bridged with IABP, potentially owing to difficulty assessing the AV in this critically ill population prior to LVAD implantation.

Outflow Graft Narrowing of the Heartmate 3 Left Ventricular Assist Device: Incidence, Imaging Findings, and Outcomes

<h3>Purpose</h3> Outflow graft narrowing or occlusion has been reported in patients with the HeartMate 3 (HM3) left ventricular assist device (LVAD) due to accumulation of biodebris external to the graft. This study assesses the impact of HM3 LVAD outflow graft narrowing on clinical outcomes and left ventricular unloading. <h3>Methods</h3> A single-center retrospective cohort study was performed among patients who received a HM3 LVAD between November, 2014 and August, 2019. All patients with a Computed Tomography Angiography (CTA) or Computed Tomography (CT) with IV contrast sufficient to evaluate the outflow graft lumen were included in this analysis. A significant narrowing was defined as a hypodensity of 4mm or greater. <h3>Results</h3> Of 165 patients who received a HM3 LVAD, 46 (28%) had qualifying imaging. Fourteen patients (30%) had any hypodensity in the outflow graft, and 10 (22%) had a significant narrowing. Median (interquartile range) hypodensity was 4.5mm (3.25 to 5.75). 12 patients had asymmetric hypodensity (example shown in Figure), 2 had circumferential hypodensity, and 1 had complete obstruction. Median distance from the pump exit to the start of narrowing was 5mm (0 to 12mm), length of narrowing was 29mm (22 to 49mm), and diameter of the outflow bend relief at most narrow area of lumen was 14mm (14 to 15mm). 41 (89%) patients had a transthoracic echocardiogram (TTE) done within 35 days of imaging, with the majority (37) having a TTE within two weeks of CT imaging. Death at one year post LVAD occurred in 0 patients with narrowing vs 2 (6%) in those without narrowing (p=0.48). Mean decrease in left ventricular end diastolic diameter compared to pre-LVAD TTE was 12% in patients with narrowing vs 19% in those without narrowing (p=0.34). <h3>Conclusion</h3> HM3 patients with outflow graft narrowing due to external compression by biodebris have similar outcomes and no difference in left ventricular unloading compared to patients without outflow graft narrowing. Additional analysis with a larger population is warranted.

A Pseudotwist Pattern of LVAD Outflow Graft Stenosis - A Cautionary Tale

Introduction Left ventricular assist devices (LVADs) play a fundamental role in treating end-stage heart failure. Outflow graft stenosis (OGS) represents a serious complication that can occur at a variable time point after the implantation, although typically of the order of months to years. Different types of OGS, both intrinsic and external, were described. Notwithstanding the etiology, this clinical scenario poses a life and health-threatening complication requiring timely and precise diagnosis followed by appropriate intervention. Case Report We present a case of a 72-years-old woman on LVAD HeartMate II (HM II) support. Three years after the index implantation, she presented with clinical symptoms of outflow graft stenosis. The patient was admitted to the hospital due to”low-flow“ alarms of HMII. The CT scan revealed distal outflow graft stenosis suggestive of kinking of the graft. Subsequent percutaneous transluminal stenting of the graft was performed. However, after the intervention, signs of hemodynamic compromise persisted. Both angiography and repeated CT scans verified peculiar pattern of the proximal shift of the stenotic segment relative to the implanted stent. Given this specific feature, a diagnosis was reclassified as a previously reported pattern of the outflow graft twist scenario, and surgical subxiphoid approach reexploration was indicated. On inspection, after disconnecting the bend relief from the pump body massive”gelly mass“ plasma transudate located in the interspace between the graft and the bend relief was observed. Immediately after removing compressing gelly mass, hemodynamic and pump parameters promptly resolved, and the bend relief was re-attached. Further patient follow-up remains uneventful to the date. Summary Our observation suggests that the diagnostic assessment of the outflow graft stenosis may be confusing and challenging. As plasma transudate likely develops over an extended period of time once a distal orifice of the bend relief already gets entrapped within the adjacent adhesion, the outflow graft may become contained within incompressible interspace while limited by tight connection to the pump body. That said, the graft constriction migration upon stenting can easily get misdiagnosed as a pattern suggestive of the intrinsic twist instead of correct”pseudotwist“ diagnosis associated with the external contained compartment compression.