Pump Exchange Research Articles

Graft Resistance Difference after HVAD to HeartMate 3 Left Ventricular Assist Device Exchange

A likely consequence of the discontinued distribution and sale of the HVAD System (Medtronic, Minneapolis, MN) will be an increase in replacement with the HeartMate 3 (Abbott, Chicago, IL) left ventricular assist device when device exchange is necessary. If part or all of the HVAD 10-mm-diameter outflow graft is retained during replacement, the HeartMate 3 will have to run at a higher speed than it would with its 14-mm-diameter graft. A steady-state, invitro study was run with 250-mm-long samples of HVAD, HeartMate 3, and half-HVAD/half-HeartMate 3 grafts and additionally 125- and 375-mm-long samples of the HVAD graft. Flows of 3.0, 3.9, 4.3, 4.7, and 6.0 L/min were applied to encompass expected clinical conditions. At typical and high flow rates of 4.3 and 6.0 L/min, HeartMate 3 rotor speeds with the full HVAD graft had to be increased relative to those with the HeartMate 3 graft from 5350 to 5700 and 6350 to 6900 rpm, respectively, with power consumption increases from 3.7 to 4.3 W (16%) and 5.5 to 6.8 W (24%), respectively. The study did not elucidate a severe consequence of using a remnant HVAD graft during pump exchange, but the incremental risks of a higher rotor speed, disadvantage to the patient in battery runtime, and the general benefit of complete conversion to the HeartMate 3 graft should be balanced against other procedural considerations. Complete graft replacement during HVAD-to-HeartMate 3 conversion remains the preferred approach from an engineering point of view.

Abstract 11868: A Reduced Anticoagulation Strategy Among Patients Supported With Ventricular Assist Device is Not Associated With Increased Mortality

Introduction: Patients with left ventricular assist device (VAD) are typically treated with aspirin and warfarin. However, some patients are unable to tolerate full anticoagulation (AC). There is limited information available regarding intermediate-term outcomes in patients on reduced or no anticoagulation. Methods: Patients who underwent VAD implantation at California Pacific Medical Center from January 2015 to January 2020 were studied retrospectively. Patients received aspirin 81 mg daily and warfarin with a target INR of 2-3, and anticoagulation was gradually de-intensified or withdrawn in response to recurrent mucosal bleeding. Pre-implantation characteristics, thrombolytic events (hemolysis, pump thrombosis requiring exchange, TIA, or ischemic CVA), and survival post-implant were compared among patients treated with full AC vs. reduced or no AC. We performed nonparametric survival analysis to obtain Kaplan-Meier survival estimates as of 9/15/2020. Cox proportional hazards regression was used to adjust for confounders measured at baseline. Results: 91 patients underwent VAD implant (80 HeartMate 3 and 11 HeartMate II). The median age was 65, and the majority of patients (79%) were treated as destination therapy. Reduced AC was used in 43 patients (47%), including no anticoagulation (12 patients), aspirin monotherapy (2 patients), warfarin monotherapy (16), warfarin monotherapy with a reduced INR target (10), and aspirin plus warfarin with a reduced INR target (3). During a median follow-up of 22 months, 15 thrombotic events were observed (12 in the reduced AC group and 3 in the full AC group, P=0.19). Two patients underwent pump exchange. 67% of thrombotic events and both pump exchanges occurred in HMII recipients. Survival was similar in both groups (Figure). Conclusions: The use of a reduced or no anticoagulation strategy after VAD implant is not uncommon and is associated with acceptable outcomes, particularly among HeartMate 3 recipients.

HVAD to Heartmate 3 Device Exchange: A Society of Thoracic Surgeons Intermacs Analysis

BackgroundOn June 3, 2021 Medtronic, Inc announced discontinuation of the HVAD left ventricular assist device. The purpose of this analysis was to provide summary data on surgical risks of HVAD to HeartMate 3 exchange and compare survival after HVAD to HeartMate 3 exchange to survival after primary HVAD implantation. MethodsThree cohorts within The Society of Thoracic Surgeons Intermacs database were identified: primary HVAD implant cohort (January 2017 to March 2021, n = 3797), HVAD to HeartMate 3 exchange cohort (December 2017 to March 2021, n = 45), and HVAD to HVAD exchange cohort (January 2017 to March 2021, n = 234). Mortality after HVAD to HeartMate 3 exchange was modeled and compared with the constant hazard phase for risk of mortality while on continued HVAD support. As a secondary analysis outcomes and survival were compared between patients who underwent HVAD to HeartMate 3 and HVAD to HVAD exchange. ResultsHVAD to HeartMate 3 exchange was associated with significantly reduced survival compared with survival while remaining on HVAD support (6 months after exchange, 73.8% [70% confidence interval, 68.6-77.8] vs 79.0% [70% confidence interval, 78.3-79] for continued HVAD support). Compared with HVAD to HVAD exchange, survival was higher after replacement with HeartMate 3 (1 year: 85.9% [70% confidence interval, 79.5-90.5] vs 66.6% [70% confidence interval, 63.0-70.0], P = .009). ConclusionsCompared with continued support on HVAD, an exchange to HeartMate 3 was found to be associated with a significant increase in mortality. For patients who required pump exchange on HVAD support, exchange to HeartMate 3 demonstrated superior survival. Currently there is insufficient evidence to support elective exchange from an HVAD to HeartMate 3.

Contemporary outcomes of continuous-flow biventricular assist devices.

Significant right ventricular failure (RVF) complicating left ventricular assist device (LVAD) placement has been reported at 10-30%. Although primarily indicated for left ventricular failure, ventricular assist devices (VADs) have become utilized in a biventricular setup to combat right ventricular failure (RVF) following LVAD implantation. With the advent of continuous-flow LVADs (CF-LVADs) superseding their pulsatile predecessors, the shift towards CF-biventricular assist devices (CF-BiVADs) come with the prospect of improved outcomes over previous pulsatile BiVADs. We aim to review the literature and determine the outcomes of CF-BiVAD recipients. A systematic review was performed to determine the outcomes of CF-BiVADs. Pre-operative demographics and device configuration data was collected. Primary outcomes evaluated were short-term survival, long-term survival, duration of support, and survival to transplant. Secondary outcomes evaluated included intensive care unit (ICU) and hospital length of stay (ICU-LOS and HLOS, respectively), pump thrombosis, pump exchange. Median and interquartile range was reported where appropriate. A major limitation was the likely overlap of cohorts across publications, which may have contributed to some selection bias. Of 1,282 screened, 12 publications were evaluated. Sample size ranged from 4 to 93 CF-BiVAD recipients, and follow-up ranged from 6 to 24 months. Mean age ranged from 34 to 52 years old. Forty-five percent of CF-BiVADs had right atrial (RA-) inflow cannulation, with the remaining being right ventricular (RV). Thirty-day survival was a median of 90% (IQR 82-97.8%) and 12-month survival was a median of 58.5% (IQR 47.5-62%). Where reported, rate of pump thrombosis (predominantly the right VAD) was a median of 31% (IQR 14-36%), although pump exchange was only 9% (IQR 1.5-12.5%). RVF post-LVAD implantation is a high morbidity and mortality complication. There is no on-label continuous-flow RVAD currently available. Thus, the modifications of LVADs for right ventricular support to combat pump thrombosis has resulted in various techniques. BiVAD recipients are predominantly transplant candidates, and complications of pump thrombosis and driveline infection whilst on wait-list are of great consequence. This study demonstrates the need for an on-label CF-BiVAD.

Pre-implant right ventricular free wall strain predicts post-LVAD right heart failure.

The aim of this study is to evaluate the predictive utility of preoperative right ventricular (RV) global longitudinal strain (GLS) and free wall strain (FWS) on outcomes following left ventricular assist devices (LVADs) implantation. Preoperative transthoracic echocardiograms were retrospectively reviewed in adults undergoing continuous-flow LVAD implantation between 2004 and 2018 at a single center. Patients undergoing pump exchange were excluded. RV GLS and FWS were calculated using commercially available software with the apical four-chamber view. The primary outcome was RV failure as defined by the Interagency Registry for Mechanically Assisted Circulatory Supportwithin 1-year post-LVAD insertion. A total of 333 patients underwent continuous-flow LVAD implantation during the study period and 137 had adequate preoperative studies for RV strain evaluation. RV FWS was found to be a significant predictor of postoperative RV failure in univariate analysis (odds ratio [OR] = 1.12, p = .03), and this finding persisted after risk adjustment in multivariable analysis (OR = 1.14, p = .04). Using the optimal cutoff value of -5.64%, the c-index of FWS in predicting RV failure was 0.65. RV GLS was not associated with post-LVAD RV failure (OR = 1.07, p = .29). PCWP was the only additional significant predictor of RV failure using multivariable analysis (OR = 0.90, p = .02). Pre-implant RV FWS is predictive of RV failure in the first postoperative year after LVAD implantation.

Driveline Fractures in the Heartmate II Left Ventricular Assist Device - A Single Center Experience in Asia

Purpose The incidence of driveline fractures among patients on HeartMate II Left Ventricular Assist Device (LVAD) support is reviewed Methods This is a single-center, retrospective review of all the patients on HeartMate II LVAD support who presented with driveline fractures. Patients’ presentation, interventions, and outcome following corrective treatment were examined. Results Between May 2009 and October 2018, 60 HeartMate II LVAD were implanted. Over a cumulative support period of 81 patient-years (maximum, 8.5 years), 15 patients (25%) had driveline fractures (age 14-70, 2 female), 5 of them were destination therapy (> 65 years old). Mean duration from the time of implant to driveline fractures was 44.5 ± 15.5 months. 12 patients had significant weight gain following LVAD implant, ranging from 5.2 to 32.3kg (median 17.4kg). While tethered on to power module, 8 patients (53.3%) encountered intermittent pump stoppage, 5 (33.3%) had transient low pump speed, 1 (6.7%) had recurrent driveline fault and 1 more (6.7%) presented with hemoserous discharge leaking from broken insulation in the external driveline with multiple recurrent low voltage advisory. Ungrounded cable was issued to 13 patients as a temporary measure with mean duration of its usage of 259 days (range 26-980 days), before corrective treatment. There were 2 patients with ongoing use of the ungrounded cable (mean 1 year). 8 patients (53.3%) underwent pump replacement, 2 with significant external driveline fractures successfully underwent external driveline replacement and 1 underwent heart transplant. Of the 9 pumps returned for analysis, 7 (78%) were found to have damaged internalized part of the driveline while 2 (22%) had circumferential fractures at the edge of the pump housing extending across the diameter of the bend relief. There were 3 mortality (20%), 1 due to recurrent pump pocket infection and pump thrombosis following the initial pump replacement for driveline fractures, 1 died of subdural haemorrhage before elective pump exchange and 1 died 3 weeks after pump stoppage. Conclusion The incidence of HeartMate II internal driveline fractures seemed to be higher in our Asian experience as opposed to what have been reported in literature. An ungrounded cable served as a temporary measure for short to shield and a timely pump exchange maybe lifesaving when driveline damage progressed into phase to phase.

RAAS Inhibition Provides Improvement in 1 Year Mortality Post LVAD Implantation

<h3>Purpose</h3> Advances have allowed left ventricular assist devices (LVAD) to be used with greater success, however, optimal medical management of LVAD patients remains unclear. <h3>Methods</h3> We performed a single-center retrospective cohort study at the University of Florida to evaluate 1-year outcomes of mortality and major adverse events in LVAD recipients. All recipients of a continuous flow LVAD between April 2005 and November 2019 were included (n=293). Demographic data, pre-operative laboratory values and medication use on discharge were collected. Patients were followed up to one year post-implantation or to time of death, transplant, or pump exchange. Cox hazards-proportional regression analysis was performed to test predictors of mortality and major adverse events of INTERMACS major bleeding and thromboembolic events . <h3>Results</h3> Patients were followed up for a median time of 12 months. Mortality occurred in 16% (n=48). There was a trend to lower mortality with time, with a HR of 0.91 for every additional year across our study period (p=0.017). On univariate analysis, predictors of a higher mortality were older age, male sex, white race, ischemic cardiomyopathy and elevated serum creatinine, while predictors of a lower mortality were use of an ACEI/ARB/ARNI on discharge and use of an aspirin dose greater than 325mg. In a multivariable model including all these variables, only older age independently predicted a higher mortality (HR 1.06 for each additional year, p-value <0.001), while use of an ACEI/ARB/ARNI on discharge was associated with a 91% reduction in mortality (HR 0.09, p-value <0.001). INTERMACS major bleeding occurred in 33% of patients, and older age was the only independent predictor of it (HR 1.02 for each additional year, p-value 0.010). Thromboembolic events occurred in 15% of patients with no identifiable predictors. <h3>Conclusion</h3> Addition of an ACE/ARB/ARNI to LVAD recipients may lead to an overall reduction in one-year mortality. Older age is associated with worse outcomes of mortality and major bleeding events.

Thromboelastography of Limited Benefit in LVAD Patient Management

Purpose The role of utilizing thromboelastography (TEG) in managing antiplatelet therapy (APT) in LVAD patients is controversial. The purpose of this study was to determine if the removal of TEG from APT protocol reduced late onset bleeding without an increase in thromboembolic events. Methods We performed a single-center retrospective cohort study at the University of Florida including all recipients of a HeartMate II, HeartMate III, or Heartware LVAD between April 2005 and November 2019 (n=293). LVAD recipients before June 1st,2017 (n=221) whose APT was monitored and adjusted using TEG were compared to LVAD recipients after June 1st,2017 (n=72) where TEG was not utilized. The occurrence of late-onset bleeding events after post-operative day 7, as defined by INTERMACs major bleeding, as well as thromboembolic events were collected. Patients were followed up to one year post-implantation or to time of death, transplant, or pump exchange. APT doses, warfarin use and INR values were collected at discharge as well as 1, 3, 6 and 12 months post-implantation. Results Over a median follow-up period of 12 months, INTERMACS major bleeding events occurred in 35% of patients where TEG was utilized compared to 29% where TEG was not utilized (p-value 0.375), and procedural intervention was required in 29% compared to 18% respectively (p-value 0.058). After June 1st 2017, patients had a higher average BMI (31 compared to 29, p-value 0.020), were more likely to be on digoxin on discharge (24% compared to 12%, p-value 0.019), and were less likely to be of white race (p-value 0.043) or have ischemic cardiomyopathy (p-value 0.019). In a multivariable Cox proportional-hazards regression model including all these variables, older age was the only independent predictor of bleeding events (HR 1.03 for each additional year of age, 95% CI 1.01-1.05, p 0.008). Use of TEG was associated with use of higher doses of aspirin (>325mg 41% vs. 0%), and use of a second antiplatelet (43% vs. 1%). There was no significant difference in thromboembolic events (15% in each). Conclusion In this single center retrospective study, thromboelastography monitoring after LVAD implantation was associated with significantly higher rates of multidrug antiplatelet regimen use, at significantly higher doses, with no difference in thromboembolic events compared to LVAD patients managed without TEG. Bleeding events were more common in elderly recipients.

Left Ventricular Assist Device Exchange to HeartMate III Using Minimally Invasive Approach

<h3>Purpose</h3> Pump thrombosis, infection or device malfunction are major complications of LVAD that may need to be treated with pump exchange. There is limited data on exchanges to HMIII. Our purpose was to review outcomes of patients undergoing any LVAD to HMIII exchange at our center using minimally invasive approach (subcostal and/or left anterolateral thoracotomy). <h3>Methods</h3> We retrospectively reviewed records of patients undergoing any LVAD to HMIII exchange from January 2016 to October 2020. Pre-operative characteristics, indication, hospitalization course and post discharge data was collected. <h3>Results</h3> Ten patients underwent LVAD (7 HMII, 2 HMIII, 1 HeartWare) to HMIII exchange. Baseline characteristics are described in Table 1. Indications for exchange were pump thrombosis (3), infection + thrombosis (2), malposition (1), malposition + thrombosis (1), outflow graft obstruction from external compression (1), outflow graft twisting and thrombosis (1) and drive line injury (1). All patients underwent minimally invasive approach but 5 needed additional sternotomy to clear abscess collection or due to anatomical complexity. Post exchange, 1 patient needed pericardial window, 1 needed short term hemodialysis, 1 had recurrence of GI bleeding, 1 had CVA on POD 1 and 3 patients needed washout and debridement or hematoma evacuation. There was no change in RV function. Mean length of stay was 20.8 ±2 days. There was only 1 re-admission (sternal wound drainage needing debridement) within 30 days of discharge. There were a total of 8 other admissions (2 for MSSA Bacteremia, 1 for HF exacerbation, 1 for GI bleeding, 1 repeat debridement of sternal wound, 1 for renal failure and 2 for unrelated reasons) within 1 year post discharge. There was no recurrence of thrombosis. Mortality was 0% at 30 days and 0% at 1 year for 5/10 patients (others are alive and less than 1 year from exchange). <h3>Conclusion</h3> LVAD to HMIII exchange with a minimally invasive approach has low surgical mortality and acceptable intermediate- term outcomes.

Effects of ACE Inhibitors, Angiotensin Receptor Blockers and Angiotensin Receptor-Neprilysin Inhibitors on Survival Free from Gastrointestinal Bleeding in HeartMate 3 Patients - A Marginal Structural Modeling Analysis

<h3>Purpose</h3> The HeartMate 3 (HM3) is superior to HMII in survival free from disabling stroke and pump exchange, however, rates of GIB remain high. Prior studies show a protective effect of digoxin and ACEi/ARB on risk for GIB, whereas phosphodiesterase 5 inhibitors (PDE5i) have opposite effect in HMII using Cox Proportional Hazard (PH) models with inverse probability weighting (IPW). Compared to this approach, marginal structural modeling (MSM) accounts for time-dependent confounding thereby producing results closer to true causal effect. Targeted Maximum Likelihood Estimation (TMLE) can help estimate MSM effects making minimal assumptions on data distribution. We studied the impact of outpt medications on survival free from GIB in HM3 pts using TMLE-MSM. <h3>Methods</h3> Data were retrospectively collected in HM3 pts up to 18 mo after discharge from implant and summarized in 3-mo time intervals. Medication status was defined as receiving vs. not ACEi/ARB/ARNi, PDE5i and digoxin at each time-node. Medication use was calculated by summarizing duration in days within each time node. Creatinine, potassium, INR and mean arterial pressure of each node were averaged. We fit TMLE-MSMs and compared results to IPW Cox PH models using both time variant and invariant covariates. Endpoint was survival free from GIB. <h3>Results</h3> 128 HM3 pts (60±13 y, 16% F) were studied. 5 deaths and 19 first GIB events occurred in 22 (17.2%) pts during follow up. 60 pts were exposed to ACEi/ARB/ARNi, 43 to digoxin and 39 to PDEi5. There was no effect of ACEi/ARB/ARNi, PDE5i or digoxin on the endpoint when using IPW Cox PH model. When using TMLE-MSM a statistically significant effect between ACEi/ARB/ARNi and the endpoint was observed (Table). <h3>Conclusion</h3> ACEi/ARB/ARNi improves survival free from GIB in HM3 pts using TMLE-MSM. Prospective randomized studies are needed to further test the impact of pharmacotherapy on outcomes in HM3 pts.

Case of Outflow Graft Obstruction from Extrinsic Compression in HM III LVAD

<h3>Introduction</h3> Pump thrombosis is an important adverse outcome to be aware of in patients with left ventricular assist devices (LVADs). While Heart Mate III (HMIII) has significantly lower rates of pump thrombosis, outflow graft obstruction remains a possibility. We present a case of outflow graft obstruction secondary to extrinsic compression at the site of the bend relief in a HMIII. <h3>Case Report</h3> A 36-year-old male with a history of non-ischemic cardiomyopathy status post HMIII as a bridge to transplant, with history of two LVAD pump exchanges due to pump thrombosis, presented with dyspnea and low flow alarms. Computed tomography (CT) of the chest demonstrated luminal narrowing with near obstruction of the outflow graft, concerning for thrombus. Urgent right heart catheterization demonstrated cardiogenic shock with elevated biventricular filling pressures. He was placed on Veno-Arterial Extracorporeal Membrane Oxygenation support and his listing status was upgraded to Status 1 for heart transplant. He was started on intravenous heparin for suspected pump thrombosis, and ultimately went on to transplant. With removal of the LVAD intra-operatively, proteinaceous material was noted between the bend relief collar and the outflow graft, leading to extrinsic compression of the graft, with no evidence of thrombus. <h3>Summary</h3> When evaluating patients with suspected outflow graft obstruction, it is important to consider not only pump thrombosis, but also the possibility of extrinsic compression of the outflow graft leading to obstruction. Distinguishing these etiologies is important as management may greatly vary.

Chances of Prolonged 5- and 10-year Survival after Continuous-Flow LVAD Implantation?

<h3>Purpose</h3> Continuous-flow LVADs (CF-LVADs) have been implanted for both bridge-to-transplant and for destination therapy. Extended survival with CF-LVADs has not been completely examined. We examined the likelihood of surviving more than 5 to 10 years with a CF-LVAD <h3>Methods</h3> We reviewed the 198 patients alive and currently being followed at our institution after CF-LVAD implantation. Patients were stratified as to type of pump implanted (HeartMate 2, HeartWare, or HeartMate 3), reason for implantation (Bridge-to-transplant or destination therapy), and length of survival (<5 years, 5-10 years, or >10 years). <h3>Results</h3> Seven (7) of the 198 patients being followed had a CF-LVAD in place and functioning for more than 10 years. 4 of these 7 patients surviving more than 10 years had not required pump exchange. There were 18 patients being followed with a CF-LVAD in place for 5-10 years. There were 173 being followed with a CF-LVAD in place for < 5 years. Of the 7 patients with a CF-LVAD in place >10 years, 6 were HeartMate 2 (HM2) CF-LVADs and one was a HeartWare (HW). Five (5) of the 7 patients with a CF-LVAD in place >10 years had the LVAD implanted as a bridge-to-transplant. Of the 18 patients with a CF-LVAD in place for 5-10 years, 9 had a HM2, 8 had a HW, and 1 had a HeartMate3 (HM3). The CF LVAD was implanted as a bridge-to-transplant in 5 of the 18 patients <h3>Conclusion</h3> Prolonged survival after CF-LVAD implantation is increasingly likely. A substantial number of patients with a CF-LVAD in place for more than 5 years originally had the device implanted as a bridge-to-transplant.

Effects and Outcomes of Pulmonary Function Testing after Left Ventricular Assist Device Implantation

Purpose The use of left ventricular assist device (LVAD) has increased significantly over the past several years. The physiologic effects of LVAD implantation on pulmonary function are not well elucidated. Studies evaluating the effects of LVAD implantation on pulmonary function testing (PFT) are inconsistent and data regarding the prognostic implications of PFT data on survival are scarce. Our study aims to evaluate the changes of PFT data after LVAD implantation in our own patient population and to assess the impact of pre-operative PFT data in regards to patient survival. Methods This was a single-center, retrospective analysis. Electronic medical records of all patients who underwent LVAD implantation at our institution between October 2011 to December 2019 were reviewed. PFTs prior to implantation were reviewed and were compared to records at 3 months and 12 months, when available. A change in a PFT value of greater than 10% was considered significant. Kaplan-Meier analysis and multivariable Cox regressions were performed to evaluate mortality. Results A total of 318 patients who underwent LVAD implantation at our center were reviewed. 44 patients who underwent pump exchanges were excluded. 81% of the patients were male and the mean age was 60 years old ± 12 years with a range of 24-83 years. Overall, there were no significant changes in FEV1 or FVC after LVAD implantation, with a mean increase of 2% and 4% in FEV1 at 3 months and 12 months respectively and a mean increase of 6% at both 3 months and 12 months in FVC. On the other hand, DLCO worsened at 3 months and 12 months and decreased by 21% and 10% respectively. A pre-operative DLCO of Conclusion Pulmonary physiology following LVAD implantation is complex. While patients with heart failure historically report improvement in dyspnea and exercise tolerance following their implant, our study indicates that a majority of their PFT values either remain unchanged or even worsen. Our analysis demonstrates a decrease in DLCO after LVAD implantation, which may be related to changes in pulmonary pressures following implantation. A pre-operative DLCO of

Impact of Using a Low Anti-Xa Target Heparin Protocol on Hemocompatibility-Related Outcomes after Implantation of a HeartMate 3 Device

Purpose To evaluate early hemocompatibility-related outcomes after implementation of a low anti-Xa target heparin protocol following implantation of the HeartMate 3 Left Ventricular Assist Device (LVAD). Methods We reviewed hemocompatibility-related outcomes including mediastinal bleeding, gastrointestinal bleeding (GIB), stroke, and pump thrombosis (PT) events in recipients of HeartMate 3 LVADs before and after implementation of a low anti-Xa target heparin protocol. The higher anti-Xa protocol targeted levels of 0.3-0.5 IU/ml using a starting dose of 18 units/kg/hr with a maximum starting dose of 1530 units/hr, and the lower anti-Xa protocol targeted levels of 0.1-0.3 IU/ml using a starting dose of 7 units/kg/hr with a maximum starting dose of 595 units/hr. Results Between 9/2018 and 8/2020, 152 patients were implanted with a HeartMate 3. Mean patient age was 57 ± 12 years, 74% were males, and 76% of patients were African American. Per our center's protocol, IV heparin was started on postoperative day 5. 106 patients were treated with the higher anti-Xa protocol and 21 patients were treated with the lower anti-Xa protocol. The patients treated with the higher anti-Xa target protocol experienced 10 (9.4%) post-operative mediastinal bleeding events requiring return to the operating room (OR) while patients on the lower anti-Xa protocol experienced none. Patients treated with the higher anti-Xa target protocol experienced 8 (7.5%) GIB events within 60 days of implant while patients on the lower anti-Xa protocol experienced no GIB. Patients treated with the higher anti-Xa protocol experienced one hemorrhagic stroke and no ischemic strokes, while patients on the lower anti-Xa protocol experienced one ischemic stroke and no hemorrhagic strokes. No PT events requiring pump exchange occurred in either group. Conclusion Implementation of a low anti-Xa target heparin protocol after HeartMate 3 LVAD implantation surgery was associated with a lower incidence of mediastinal and GI bleeding. No PT events requiring pump exchange were observed in either group. Stroke rate was low in both groups. Further research is needed to determine the safest and most effective anticoagulation protocol after HeartMate 3 implantation that lowers the incidence of early hemocompatibility-related events.

Clinical Outcomes of Ventricular Assist Device for Failing Bidirectional Glenn Physiology

Purpose The number of patients with failing single ventricle physiology is increasing, and ventricular assist device (VAD) support in this population is challenging. The purpose of this study was to describe our clinical experience with VAD for failing Glenn physiology. Methods A retrospective review of clinical outcomes was conducted in patients that underwent durable VAD placement for failing Glenn circulation between 2010 and 2020 at Texas Children's Hospital. Results Ten patients met inclusion criteria; all had a morphologic right ventricle (RV): 6 hypoplastic left heart syndrome/variant and 4 with isomerism with RV dominant atrioventricular septal defect. INTERMACS profiles were 1 in 3 patients (1 with ECMO) and 2 in 7 patients. Four patients were intubated. Age, weight, and body surface area at VAD implantation were 3.2 (0.9-10.1) years, 13.0 (7.7-22.8) kg, and 0.50 (0.36-0.90) m2, respectively. The device-strategy included HVAD in 6, Jarvik 2015 in 1, and Berlin cannula (with Berlin and/or Rotaflow pumps) in 3. Concomitant Fontan completion was performed in 5 patients (1 with fenestration), while the other 5 remained with Glenn circulation. PaO2/FiO2 ratio (median, range) on postoperative day 1 was significantly higher with Fontan completion [192 (53-336)] than without [76 (59-78), p=0.05] except a patient with Glenn circulation on ECMO. The median duration of mechanical ventilation after VAD was 2 days (range, 1 - 14). There was 1 early mortality 8 days after HVAD placement with Fontan completion due to neurologic insult intraoperatively. The remaining 9 patients (90%) were bridged to transplant at a median support duration of 3.8 (0.1-16.6) months. Five of the 6 HVAD patients were able to be discharged home prior to transplant. One patient encountered a pump thrombus requiring pump exchange and 1 patient suffered a thromboembolic stroke due to a mobile intraventricular thrombus. One patient had a subdural and subarachnoid hemorrhage 27 days after VAD implantation, with complete neurologic recovery without deficits. Conclusion This single-institutional experience suggests long term VAD support is sustainable for failing Glenn physiology with accompanying Fontan completion in selected patients. Further studies are warranted to optimize long term VAD support in this challenging population.

Long-Term Outcomes of Adults with Congenital Heart Disease Supported by Durable Continuous-Flow Ventricular Assist Devices

<h3>Purpose</h3> End-stage heart failure is a leading cause of morbidity and mortality in adult congenital heart disease (ACHD) patients; however, advanced therapies such as ventricular assist devices (VADs) are rarely implemented in this population. The aim of this study was to examine the outcomes of ACHD patients supported by durable continuous-flow VADs. <h3>Methods</h3> We performed a retrospective review of patients with congenital heart disease >18 years of age at time of VAD implantation at Texas Children's Hospital and Baylor St. Luke's Medical Center from 2011-2020. <h3>Results</h3> In total, 13 patients (median age 34 years [IQR, 24-47]) received a VAD <b>(Table)</b>. All devices were implanted in the subaortic ventricle; 2 patients (15%) and 11 patients (85%) had moderate and great complexity congenital heart disease, respectively. Prior to implantation, 11 patients (85%) required inotropic support and 5 patients (38%) required temporary mechanical circulatory support. 12 patients (92%) survived to hospital discharge with a median postoperative LOS of 36 days (IQR, 27-50). Among those who survived to hospital discharge, all (100%) were NYHA class I or II at follow-up and the median duration of support was 816 days (IQR, 160-1629). Patients experienced device-related complications including neurologic events (n = 5; n = 2 disabling stroke), driveline infections (n = 3), presumed device infections requiring chronic antibiotic therapy (n = 4; n = 1 associated pump exchange), GI bleeds (n = 6), and presumed pump thromboses (n = 5; n = 2 associated pump exchanges). Overall survival (heart transplant censored) at 1, 3, and 5 years was 82%, 70%, and 32%, respectively. 2 patients (50%) were successfully bridged to transplant and 1 patient initially implanted as destination therapy eventually received a transplant. <h3>Conclusion</h3> Our data demonstrate that durable VADs can be used effectively in ACHD patients with end-stage heart failure and support efforts to more readily utilize these therapies in this population.

Emergent Left Ventricular Assist Device Pump Exchange Concomitant with Aortic Valve Closure Due to Pump Thrombosis and Aortic Insufficiency

Emergent Left Ventricular Assist Device Pump Exchange Concomitant with Aortic Valve Closure Due to Pump Thrombosis and Aortic Insufficiency

Evaluation of Thoracotomy versus Median Sternotomy Approach in Third-Generation Left Ventricular Assist Device Implantation

<h3>Purpose</h3> The purpose of this study is to compare short term results of patients undergoing a third generation (HVAD™or HeartMate™ 3) Left Ventricular Assist Device (LVAD) implantation through either minimally-invasive, thoracotomy approach or standard median sternotomy. <h3>Methods</h3> We prospectively collected data on all patients at our institution that received an LVAD from September 2008 to February 2020. Surgical approach was decided by the implanting surgeon. We used 1:1 propensity score (PS) matching to compare the sternotomy versus thoracotomy groups. A logistic regression model based on 19 explanatory variables was used to estimate the propensity score. Overall survival post-implantation was summarized using Kaplan-Meier curves and compared using the log-rank test. <h3>Results</h3> A total of 272 patients were included, of whom 194 had sternotomy and 78 had either left thoracotomy and hemi-sternotomy or bilateral thoracotomies. Using PS matching, 128 (64/64) patients were selected. Demographics and operative characteristics were well balanced between groups. Overall, there was a trend towards better survival in thoracotomy group (33.1% vs 66.4%, p=0.06) at 5 years, but higher stroke rate (11% in sternotomy group vs 21% in thoracotomy group, p = 0.035). Following PS-matching, however, there was no difference in early or late mortality (Graph 1) but there was a higher rate of pump exchange in the thoracotomy group (2% vs 9%, p = 0.052). There was no difference in perioperative stroke rates (sternotomy 6% vs thoracotomy 9%), extubation time (2.5 days vs 2.5 days), right ventricular failure (13% vs 14%), renal failure (8% vs 5%) or hospital readmissions (81% vs 88%). <h3>Conclusion</h3> Minimally invasive LVAD implantation is feasible and safe in the current LVAD era. In a PS matched analysis, patients in the minimally invasive group displayed lower overall mortality, but without reaching statistical significance. Adverse events were similar in both groups.

Fusion Cardiac Resynchronization Therapy in an LVAD Patient from Two Devices and Crossing Leads

<h3>Introduction</h3> Cardiac implanted electronic devices (CIEDs) have significantly improved the survival and quality of life in heart failure patients. The role of implantable cardioverter defibrillators (ICD) and cardiac resynchronization therapy (CRT) in patients with a left ventricular assist device (LVAD) has not been well defined. CIED procedures come at a price of venous access problems, lead malfunctions and pocket complications. This requires creative approaches to tackle CIED related issues in LVAD patients. <h3>Case Report</h3> Here we describe the clinical course of a 67 year old patient with an LVAD as destination therapy. The heart failure etiology was a non-ischemic cardiomyopathy due to sarcoidosis and he was pacing dependent due to a total atrioventricular block. The patient had an ICD due to recurrent monomorphic ventricular tachycardias and a CRT indication due to previous deterioration of (right sided) heart failure in the temporary absence of biventricular pacing. He recently had a pump thrombosis which was treated medically as he was deemed too frail to undergo a pump exchange. The anticoagulation regimen consisted of a vitamin K antagonist (INR 2.5-3.0) and clopidogrel 75mg o.d.. The patient was admitted for a pulse generator exchange due to low battery voltage. We were confronted with impeding right ventricular lead failure and bilateral venous access problems due to chronic subclavian vein occlusions in a patient with 5 transvenous leads, therapeutic anticoagulation and pronounced thoracic collaterals (Fig 1). Several strategies were considered - venous angioplasty, contralateral lead tunneling and epicardial lead implantation. We sought for a creative solution to deliver biventricular fusion pacing with the existing leads from two contralateral pulse generators. This provided the least invasive solution to deliver effective CRT. <h3>Summary</h3> This case illustrates the complexity of CIED related decision making in pacing dependent LVAD patients, particularly those with an ICD and CRT indication.

Cool seal unit obstruction as an unusual cause of pump exchange of centrifugal pump EVAHEART

Cool seal unit obstruction as an unusual cause of pump exchange of centrifugal pump EVAHEART