Ventricular Assist Device Research Articles

Utilization and Outcomes of Temporary Percutaneous Right Ventricular Assist Devices in Cardiogenic Shock

Acute right ventricular failure (RVF) is a common finding in cardiogenic shock (CS), yet the optimal method of supporting the failing RV remains unclear. This study aimed to describe CS patients receiving percutaneous right ventricular assist devices (pRVADs) using the multicenter Cardiogenic Shock Working Group (CSWG) registry. Among 6,201 patients with CS, 152 (2.4%) received pRVADs, with ProtekDuo and Impella RP being used in 71% and 29% of cases, respectively. The average age of this group was 58.5 years, with a higher proportion of men (66.4%). Heart failure–associated CS (HF-CS) was observed in 48% of patients, while myocardial infarction–associated CS (MI-CS) was seen in 27% (HF-CS versus MI-CS: 52.8% vs. 21.3% for ProtekDuo; 36.4% vs. 40.9% for Impella RP; p = 0.01). The overall in-hospital mortality rate was 54.6%, bleeding complications were more prevalent among ProtekDuo recipients (64.8% vs. 43.2%, p = 0.008), whereas Impella RP recipients had shorter hospital stays (20.4 ± 18.7 vs. 41.9 ± 31.5 days, p < 0.001). ProtekDuo was more commonly used in patients with HF-CS and was associated with higher rates of bleeding and longer hospital stays compared with Impella RP, although overall mortality was similar. Further investigation is required to determine the ideal timing and clinical conditions warranting pRVAD deployment in CS.

Abstract 4136813: Redox Serum Proteomics Of Left Ventricular Assist Device Unloaded Human Heart

Heart failure (HF) is a global epidemic claiming millions of lives worldwide. Unloading the heart of end-stage HF patients via left ventricular assist devices (LVADs) is used not only as a bridge to transplantation but also as a bridge to recovery in certain selected patients. To date, assessment of patients’ recovery from HF is based on clinical and symptomatic evaluation. The use of non-invasive biomarkers that monitor the remodeling/reverse remodeling associated with HF progression/recovery is still lacking. In this study we applied mass spectrometry-based quantitative redox proteomics to identify serum biomarkers to monitor both the progression of HF and its recovery after LVAD treatment. A fingerprint of reversed behavior at the protein and at the oxidized Cys peptide level has been discovered when comparing HF and LVAD patients. HDL proteins related to lipid metabolism were decreased in HF samples and increased in LVAD patients. In addition, a number of inflammatory proteins showed a decrease in LVAD samples and an increase in HF samples. In particular APOA4, C7, F2 or SAA2 discriminated between HF and LVAD patients. A pool of peptides containing specific oxidized Cys residues showed an inverse relationship in HF as opposed to LVAD samples. Oxidized Cys-containing peptides derived from Albumin, IGK and IGG1 discriminated HF from LVAD samples. Discriminatory sensitivity and specificity were enhanced by using a combination of the proteins APOA4, C7, F2 and the above-mentioned peptide derived from Albumin. Responders and non-responders could also be separated by proteins such as APOA4, and Cys-oxidized peptides, such as the ones derived from Albumin or IGK mentioned above. This is the first study to apply redox proteomics to explore the protein profile of the LVAD unloaded human heart. These data suggest that HDL plays an important role in LVAD recovery and that a specific group of peptides is associated with the recovery process; the mechanisms involved need further study. Our data could have important implications to the management of patients in the LVAD recovery program and could serve to identify new therapeutic targets.

Prosthetic Valve Fate in Patients With Continuous-Flow Left Ventricular Assist Devices

Prosthetic valve-related morbidity and mortality in patients with left ventricular assist devices (LVADs) remain unclear. We retrospectively reviewed patients who received a HeartMate II or 3 LVAD at our center between April 2004 and December 2022. Patients with a valve prosthesis in any position were included. Of the 726 LVAD recipients, 74 (10.2%) underwent valve replacement before (n = 37, 50.0%), concomitantly with (n = 32, 43.2%), or after (n = 6, 8.1%) LVAD insertion. Prosthetic valves were implanted in the aortic (n = 32), mitral (n = 23), and tricuspid (n = 26) positions. Mechanical valves were present in eight (three aortic, five mitral) patients. At a median follow-up of 1.97 years post-VAD (interquartile range [IQR]: 0.56–4.58 years), there was one valve-related death due to severe aortic bioprosthetic insufficiency. Five of 28 (17.9%) patients with an aortic bioprosthesis had evidence of dysfunction on follow-up echocardiography. Median time to first sign of aortic bioprosthetic valve dysfunction was 1 (IQR: 0.6–5.1) year from time of LVAD with the prosthesis in place and 10.8 (IQR: 9.5–12.6) years from date of initial valve insertion. Prosthetic valve-related mortality or reinterventions are uncommon in patients with LVADs; however, bioprosthetic aortic valve dysfunction can develop less than 1 year after LVAD implantation.

Abstract 4144502: Comparing Readmission Rates and Exercise Capacity Following Left Ventricular Assistive Device Placement With and Without Post-Operative Inpatient Rehabilitation

Introduction: Patients with heart failure may undergo mechanical assistive device placement as a bridge to heart transplantation or for destination therapy. Thereafter, patients may be discharged home or admitted to inpatient rehabilitation. Research Question: We hypothesized that within 8 months, patients admitted to inpatient rehabilitation (IR) would have fewer readmissions and greater exercise capacity compared to patients discharged home following left ventricular assistive device (LVAD) placement. Aim: The readmission rates and exercise capacity of patients admitted to (IR) were compared to those discharged home within 8 months of (LVAD) placement. Methods: Readmission rates, impairment percentages (IP) (determined by Activity Measure for Post-Acute Care scores) and walking distance after (LVAD) placement between March 1 st , 2020 to November 30 th , 2022 were collected via retrospective chart review at Jackson Memorial Hospital. Adults with heart failure and heart assistive device (ICD10 code Z95.811), discharged home or admitted to the Christine E. Lynn Rehabilitation Center for at least 7 consecutive days within 8 months were included. Patients who were noncompliant, expired, transferred, or unable to ambulate were excluded. 24 patients were admitted to rehab, and 16 were discharged home. Statistical significance was denoted at the 0.05 level using the Mann-Whitney U Test. Results: There was a higher proportion of females in the rehab group (45.8%) and males in the no rehab group (93.8%) (p=0.02). The groups were otherwise comparable. Average (IP) at hospital discharge was higher for the rehab group (51.79%, SD 17.65) compared to the no rehab group (14.20%, SD 18.93) (p<.001). Average post-(LVAD) walking distance (feet) at hospital discharge was higher for the no rehab group (305, SD 206.72) compared to the rehab group (127.73, SD 132.11) (p=0.005). Within 8 months, there was no significant difference between groups. Average readmissions were higher for the no rehab group (1.375, SD 0.957) compared to the rehab group (0.958, SD 1.49) (p= 0.059), but was not statistically significant. Conclusions: Patients with greater (IP) and shorter walking distances were admitted to rehab and became functionally comparable to the no rehab group by 8 months. Though readmission rates were lower for the rehab group, this was not statistically significant. Additional studies are warranted to evaluate the impact of (IR) following (LVAD) placement.

Abstract 4134778: Myocardial Recovery and Survival after Weaning of Left Ventricular Assist Device Therapy in Patients with Toxic and non-Toxic Cardiomyopathy, A Canadian Experience

Left ventricular assist devices (LVAD) are increasingly used in refractory heart failure, mainly as a bridge to transplant or as destination therapy. LVAD unloading of the left ventricle (LV) can also promote myocardial recovery leading to improvement of the LV systolic function, allowing LVAD explantation. However, parameters associated with LVAD weaning and long-term outcomes are not well documented. The aim of this study was to assess the clinical and echocardiographic characteristics of weaned patients and to evaluate their event-free survival post-explantation. We conducted a single-center retrospective study recruiting patients who underwent a second or third generation LVAD implantation at a Canadian cardiology center between November 2009 and October 2021. A total of 98 patients underwent LVAD implantation during this period. All patients were on guideline-directed medical therapy (GDMT). Fourteen patients (14%) had significant LV recovery and were explanted/decommissioned after a median support time of 309 days (range 55-595 days). Toxic cardiomyopathy, defined as abuse of amphetamines (n=2), energy drinks (n=2) or multiple substances (n=6), was the most likely diagnosis in 10 of the weaned patients (71%). The LVEF was significantly higher and the left ventricular end-diastolic diameter (LVEDD) was significantly lower in weaned patients compared to unweaned patients after 3 months of support. Myocardial recovery manifested as pump thrombosis in 4 of the weaned patients (29%). Prior to explantation, 12 patients had a decrease in GDMT doses to minimize post explantation vasoplegia. After explantation, median follow-up time was 40 months (range 8-109 months) and the majority of patients were anticoagulated for 3 months. At last follow up, the LVEF was 44±6% and no patient had a LVEF below 35%. All patients were NYHA I or II and no death, heart transplant, or mechanical support initiation occurred. LVAD therapy can induce LV reverse remodeling leading to myocardial recovery in a significant proportion of patients, especially young patients with toxic and non-ischemic cardiomyopathies. Early reverse remodeling with decreasing LVEDD and improving LVEF at 3 months following implantation is associated with successful weaning. Pump thrombosis seems to be associated with LV reverse remodeling and weaning of mechanical support in certain patients. Weaned patients maintain satisfactory LVEF recovery after explantation and have good long-term event-free survival.

Abstract 4138583: Incidence and Outcomes of Heparin-Induced Thrombocytopenia Among Patients Undergoing Left Ventricular Assist Device Implantation

Background: Left Ventricular Assist Devices (LVAD) are being increasingly used as a bridge to transplant and destination therapy for advanced (stage D) heart failure. Heparin-induced thrombocytopenia (HIT) increases the risk of thromboembolic and bleeding events. HIT is also a well-known complication in patients undergoing LVAD implantation. This study examines the incidence and impact of HIT on outcomes in LVAD implants using a nationwide database from 2016 to 2020. Methods: We queried the National Inpatient Sample database for 2016-2020 to identify all adults ≥ 18 who underwent LVAD insertion using ICD 10 codes. LVAD recipients were dichotomized into two cohorts by the presence of HIT. Our primary outcome was in-hospital mortality. Secondary outcomes included vascular complications, acute kidney injury (AKI), length of stay, and total cost. Outcomes were adjusted for demographic variables, hospital-level characteristics, and comorbidities using regression analysis. Results: A total of 19975 (95% CI: 18328 - 21622) hospitalization records for LVAD insertion were identified, out of which HIT occurred in 1.8%. There were significant differences in AKI requiring dialysis, (p < 0.03) cardiogenic shock, (p<0.01), mechanical ventilation (p<0.01), pulmonary embolism (PE) (p< 0.001) and acute deep vein thrombosis (DVT) (p< 0.001) which occurred more in HIT. In-hospital mortality was not significantly associated with HIT (adjusted odds ratio [aOR] 1.49, 95% CI :0.73-3.04, p value 0.28). Older age (aOR 1.02; 95% CI: 1.01-1.02) was associated with mortality after LVAD insertion. AKI, ischemic stroke, hemorrhagic stroke, acute coronary syndrome, arterial dissection, cardiogenic shock, and mechanical ventilation were significantly associated with in-hospital mortality. Our analysis did not show any differences in the incidence of vascular complications, stroke, intraoperative bleeding, blood transfusions and AKI between the HIT and non-HIT group. The HIT group stayed longer in the hospital 39 days (95% CI: 36- 38) vs 37 days (95% CI: 35- 44) and incurred higher total hospital cost of $1,101,638 vs. $1,245,616) although this was not statistically significant. Conclusion: Among US hospitalized patients undergoing LVAD implants, HIT was significantly associated with a higher risk of AKI requiring dialysis, PE, acute DVT, cardiogenic shock and need for mechanical ventilation. It was however not associated with a higher risk of in-hospital mortality.

Abstract 4138350: Candidemia in Patients with Left Ventricular Assist Device-A Case Series

Introduction: Candidemia is rare but associated, have significant morbidity and mortality. Outcomes are not well-characterized in patients with left ventricular assist devices (LVADs). With an increasing number of patients living with LVADs, we sought to characterize risk factors to help optimize outcomes for this high-risk population. Methods: We retrospectively reviewed records of 97 patients who underwent LVAD implant between January 2012 to May 2024 at Indiana University Health, Indianapolis Indiana. Demographic and clinical data were extracted. Candidemia was defined as a positive blood culture with candida species. Result: We identified three patients with candidemia, with an overall attack rate of 3.09%. All patients had a HeartMate III (HM3) at the time of infection. The mean age of patients was 40.3 years (Range 29.0 – 58.0 years) and mean BMI was 35.7 kg/m 2 (Range, 30.0 – 42.0 kg/m 2 ). One patient grew Candida auris and Candida tropicana, the other patient grew Candida auris and the third patient grew Candida globrata. All patients had an automatic implantable cardiac defibrillation, a peripherally inserted central catheter line, and right heart failure. Two patients had driveline infections (one fungal, one bacterial) while one patient developed LVAD endocarditis with a right ventricular outflow tract vegetation. Two patients had persistently positive blood cultures despite treatment with a multi-drug anti-fungal regimen (Flucytosine, Amphotericin B and micafungin) and expired. The third patient initially cleared her blood cultures after treatment with IV micafungin only but was re-admitted with muti-organ failure and expired. Summarily, all patients with candidemia died with a mortality rate of 100%. None of the patients were candidates for heart transplantation. Average survival from the time of diagnosis of candidemia was 5 months (Range 1.0 – 11.0 months). RHF, chronic DL infection and high BMI were associated with candidemia in our series. Conclusion: Candidemia in LVAD patients, while less common than bacterial infections, carry high mortality without cardiac transplantation (100% mortality in our cohort). Its rare occurrence makes it challenging to identify reversible risk factors, leading to poor survival. Multicenter registries are needed to fully elucidate these risk factors and determine effective treatment strategies.

Abstract 4113336: Characteristics and Outcomes of Ventricular Tachycardia Ablation in Patients with the HeartMate 3 Left Ventricular Assist Devices: Results From a Large Single-Center Registry

HeartMate 3 (HM3) is a fully magnetically levitated continuous flow left ventricular assist device (LVAD). In patients with HM3 and recurrent ventricular tachycardia (VT), data on the outcomes of catheter ablation (CA) are insufficient. We report our institutional experience with CA of VT in patients with the HM3.Consecutive patients with HM3 and recurrent drug-refractory VT undergoing CA were included. Ablation sites were identified using activation/entrainment mapping (stable VTs) and/or late/fractionated potential ablation and pace-mapping (unstable VTs). Between 2016-2023 a total of 431 patients (age 58±13, INTERMACS 3±0.98, 44% ischemic cardiomyopathy) received an HM3 LVAD at our institution. Of these, 15 (3.4%) underwent CA for recurrent VT despite therapy with 1.3±0.8 antiarrhythmic drugs a median of 700 days from the LVAD surgery (2 patients <1 month from the surgery). The LV access was transseptal in 12 (80%) cases, retrograde aortic in 2 (13%) and both in 1 (7%). A total of 23 distinct VTs were targeted. Of these, 21 (91%) were mapped with activation/entrainment mapping, always utilizing an intracardiac RV reference due to excessive surface ECG noise, and 2 (9%) were hemodynamically unstable with reduced LVAD flows and targeted with substrate-based ablation. A total of 3 (13%) VTs were targeted adjacent to the HM3 inflow cannula, and 20 (87%) from substrate remote from the HM3 cannula. At post-procedural programmed ventricular stimulation, non-inducibility of all targeted VTs was achieved in 13 (87%) patients, 1 patient had residual inducible clinical VT, and in 1 patient no post-procedural programmed stimulation was performed. Periprocedural complications occurred in 1 (7%) case (small pericardial effusion not requiring intervention). At 12 months follow-up following the index procedure, no death occurred and one patient received heart transplantation. Of the remaining 14 patients, 6 (42%) remained free from VT (2 with VT ablation <1 month post-LVAD and 12 with VT ablation >=1 month post-LVAD). In this large single-center HM3 registry, a minority of patients underwent CA for recurrent drug-refractory VT (3.4% over a 7-year period). CA of VT in HM3 recipients is feasible and appears safe also when performed soon after LVAD surgery. Myocardial scar from the underlying cardiomyopathic process rather than the apical cannula is the dominant substrate responsible for VT in these patients.

Abstract 4116410: A Novel Deep Learning Approach for Prediction of Right Heart Failure After Left Ventricular Assist Device Implantation using Pulmonary Artery Pressure Tracings

Introduction: Left ventricular assist device (LVAD) offers a lifeline for advanced heart failure patients, but ~30% experience post-operative right heart failure (RHF) with significant morbidity and mortality. Current methods for predicting RHF risk have limited accuracy. This study is the first of its kind to explore the feasibility of using a convolutional neural network (CNN) deep learning model with pulmonary artery pressure (PAP) tracings acquired during pre-operative hemodynamic assessment to identify patients at risk for early RHF. Methods: A CNN model was pre-trained on PAP tracings from the MIMIC-III Waveform Database to leverage transferable knowledge and improve model performance. The model learned general features and temporal relationships in hemodynamic tracing morphology for RHF prediction. It was then adapted for classification by modifying the output layers. Post-LVAD RHF was definitively adjudicated for each instance included from our 246 patient single center LVAD database. RHF was adjudicated using the 2020 Academic Research Consortium defintion. The database included 205 non-RHF instances and 41 RHF instances. We developed a novel signal processing method utilizing computer vision to extract PAP waveform data from pre-operative right heart catheterization reports. Data was reviewed to ensure accurate pressure tracing representation. SMOTE-ENN (synthetic oversampling) and class weighting addressed dataset imbalance during training to enhance model generalizability and RHF prediction accuracy. Results: The model achieved strong performance in classifying RHF from non-RHF outcomes, as evidenced by consistent AUC scores of 0.87 and 0.85 on validation and unseen test data, respectively. These findings indicate the potential for hemodynamic tracings to predict RHF after LVAD implantation. Notably, the model maintained its performance on unseen data, highlighting its generalizability. Conclusions: This study explored the feasibility of using a deep learning model for RHF risk stratification in patients with LVADs. The model, pre-trained on PAP tracings, achieved promising classification performance assessed by AUC. Further validation with larger, more diverse datasets will refine model performance and enhance generalizability for clinical application. Leveraging hemodynamic tracings within a deep learning framework holds promise for improved clinical outcome prediction.

Abstract 4117646: The Ultimate Test in Hemocompatibility: HeartMate3 Restart After Prolonged Pump Shut Down

Introduction: The HeartMate 3 (HM3) LVAD, was shown to have a higher survival free of hemocompatibility related adverse events (HRAE) compared to its predecessors (HM2, HVAD). Superior HM3 outcomes are attributed to wide blood flow pathways coupled with frictionless movement and intrinsic pulsatility, reducing shear stress and blood stasis. It is unknown if improved hemocompatibility can withstand pump restart after prolonged shutdown. We herein report a case of HM3 pump stoppage without subsequent HRAE. Case Presentation: A 41-year-old male underwent HVAD implant in 2019 for advanced non-ischemic cardiomyopathy. This was exchanged to HM3 for recurrent neurological events despite therapeutic anticoagulation. Ten months after exchange, he awakened one morning to find his LVAD had been off for an unknown period but had not heard any device alarms (85dB if on battery power, 165dB if on wall power). Since he felt well he changed to battery power resulting in immediate pump restart. Log file analysis showed pump stoppage 2 am – 10 am, without preceding low flow alarms or power elevations. Management and Outcomes: In the ER INR was 1.5 (2.8 one week prior) and systemic heparin was started. Evaluation included: 1) CT brain without acute infarcts 2) echocardiogram without intracardiac thrombus 3) CT Angiography with patency of the inflow cannula and outflow graft 4) stable serial LDH measurements. The controller was exchanged, and analysis noted normal function. 1-year later the patient is maintained on warfarin and aspirin 325mg without further HRAE. Given the patient’s neurologic history and pump stoppage event, we did not invoke ARIES trial guidance and thus continued aspirin. Conclusion: Pump stoppage occurs when there is complete battery depletion, disconnection of both power leads, or the percutaneous lead from system controller. Our case is unique in that the duration of pump shutdown was 8 hours and INR subtherapeutic, without HRAE in the background of neurologic events on HVAD support. It has been previously reported that complete outflow graft thrombosis can occur shortly after LVAD decommissioning. The HM3 User Manual recommends restarting the pump immediately if off for a few minutes and using clinical judgment for longer durations due to increased risk for thromboembolic events. Our case adds to the paucity of existing data on improved hemocompatibility of the HM3 during rare circumstances of the ultimate test in hemocompatibility: complete pump shut down.

Abstract 4137107: The Impact of Race in the Evaluation Process for Advanced Heart Failure Therapies

Introduction: Racial and socioeconomic disparities in heart failure therapy and heart transplantation have been well described. Potential racial disparities during the evaluation process for advanced heart failure (AHF) therapies is not well understood. We examined whether there were differences by race in the evaluation process for heart transplantation or left ventricular assist device (LVAD) implantation. Methods: Adult patients who underwent heart transplant or LVAD evaluation between May 1, 2014 – Dec 31, 2022 at the University of North Carolina Medical Center were included. Logistic regression models assessed whether approval for heart transplant listing or LVAD implantation differed by race. The multivariate model adjusted for demographic and clinical characteristics, LVEF, RV function, and substance use. Secondary outcomes assessed included the time between critical points in the evaluation process: first clinical encounter with an AHF specialist, evaluation initiation, and final decision. Results: The study cohort included 611 patients (304 non-Hispanic Black patients, 307 non-Hispanic White patients). Black patients were younger than White patients (52.4 vs. 60.7 years), less male-predominant (65.5% vs. 81.4%), with less ischemic cardiomyopathy (16.8% vs. 58.3%, all p<0.05). There was no significant difference in approval for advanced therapies between Black and White patients (unadjusted OR [95% CI]: 1.24 [0.90-1.72]; adjusted OR 0.98 [0.64-1.48]). Male sex was associated with a higher likelihood of approval for AHF therapies (adjusted OR 1.55 [1.02-2.36]). Age (OR 0.98 [0.96-0.99]) and creatinine (OR 0.66 [0.53-0.82]) were associated with a lower likelihood of approval for AHF therapies. Black patients had a significantly longer time interval from the first AHF specialist encounter to the initiation of evaluation for AHF therapies (median 45.5 vs. 14 days, p <0.01), and from the initiation of the evaluation process to the final decision (25.5 vs. 14 days, p <0.01). Conclusions: Male patients had a greater approval rate for advanced heart failure therapies. Black and white patients did not have significantly different approval rates for LVAD implantation or listing for heart transplantation. However, the evaluation process was longer for black patients. Further work is needed to investigate which factors contribute to these racial and sex differences in the evaluation and approval process for advanced heart failure therapies.

Abstract 4135194: Safety and Efficacy of Mechanical Circulatory Support during VT ablation

Introduction: Ventricular arrythmias are prevalent in patients with advanced heart failure and associated with increased mortality. Outcomes of electrophysiology ablation on patients requiring mechanical circulatory support (MCS) are not well described. We aimed to analyze the safety and efficacy of ventricular tachycardia (VT) ablation in patients requiring MCS at the Emory system. Methods: Patients were identified via retrospective chart review from October 2022 through August 2023. Patients who underwent VT ablation with the support of Impella, left ventricular assist device (LVAD), intra-aortic balloon pump (IABP), and venoarterial extra-corpeal membrane oxygenation (VA ECMO), or any combination of these were included. Results: A total of 7 patients of average age 56 ± 10 years, predominantly male (85.7%), with cardiomyopathy of mean EF 18.6% +/- 8.5 (ischemic 71.4%) underwent MCS supported VT ablation. One patient had 2 separate VT ablation procedures for refractory VT. Of these 8 procedures, 4 utilized a single type of MCS (2 impella, 2 LVAD) while 4 used a second type of MCS in combination with an Impella (2 impella RP, 1 VA ECMO, 1 IABP). Success at time of ablation was present in 75% of cases. Average time of outpatient follow up was 82 ± 31 days. At time of follow up, 50% of patients remained free of VT or with a single VT episode not requiring implantable cardioverter-defibrillator (ICD) shock. One patient had gone on to undergo successful heart transplantation. Procedural complications were noted in one patient, who suffered cardioembolic cerebrovascular accident (CVA) 2 days post-op. Transthoracic echo (TTE) 5 days post-op revealed LV mural thrombus as likely etiology of CVA. Conclusion: While there are no clear guidelines directing the use of MCS during VT ablation, our single academic institution experience suggests safety and feasibility of its use to support select, high risk cases.

Abstract 4136267: Racial and ethnic disparities in-hospital outcomes after out-of-hospital cardiac arrest: Insight from the United States national inpatient sample

Background: Out-of-hospital cardiac arrest (OHCA) continues to have a high mortality with an overall survivability to hospital discharge of less than 10%. Increased bystander cardiopulmonary resuscitation has resulted in better survival after OHCA. Some studies have tackled sociodemographic characteristics and rates of survival, but these are mostly localized studies with varied results. We investigated racial disparities in in-hospital mortality and mechanical circulatory support (MCS) use in OHCA. Methods: Retrospective cohort study based on the 2019-2020 National Inpatient Sample database of the Healthcare Utilization Project. Our population included patients 18 years or older with out-of-hospital cardiac arrest (OHCA) identified using ICD-10 codes. The primary risk factors examined were race/ethnicity categorized into White, Black, and Hispanic. The primary outcome was in-hospital mortality among patients with OHCA. The secondary outcome was mechanical circulatory support (MCS) use. Left ventricular assist device (LVAD), extracorporeal membrane oxygenation (ECMO), and intra-aortic balloon pump (IABP) were identified as MCS. Multivariate regression analysis was used to estimate the odds ratio. Results: During the study period, 26,640 hospitalizations with OHCA were identified, of whom 67,4% were White, 22,9% were Black, and 9,7% were Hispanic. The mean (SD) age of patients with OHCA was 65.2 (16) years old, and Black patients well as Hispanic patients had lower mean age compared to White patients (63.1 vs 63 vs 66.3 years old, p<0.001). A total of 19,425 died (72.9%) and 0.9% needed MCS. Notably, more Hispanics needed MCS, compared to White and Black patients (1.7% vs 0.9% vs 0.4%, p=0.049). In the multivariate analysis, we did not find statistical significance among racial/ethnic groups regarding in-hospital mortality. However, Hispanic patients had higher odds of MCS (OR=2.4; CI 95% 1.05-5.55, p=0.039) compared to White patients. No statistical significance was found regarding the use of IABP or LVAD. Conclusion: Overall, in-hospital mortality was elevated. Moreover, our findings highlight significant racial disparities after OHCA regarding MCS use. More research is needed to identify factors of racial disparities to improve outcomes.

Abstract 4144595: Real-World Outcomes of Impella 5.5 in Advanced Heart Failure Patients Undergoing Evaluation for Heart Transplant

Background: Impella 5.5 provides robust support as temporary mechanical circulatory support (t-MCS) device in advanced heart failure patients in cardiogenic shock. Understanding short- and long-term outcomes is crucial. Hypothesis: Impella 5.5 supports advanced heart failure patients in cardiogenic shock and successfully bridges them to cardiac replacement without affecting long-term survival. Methods: From February 2020 to April 2024, all patients who received an Impella 5.5 and underwent evaluation for advanced therapies at Houston Methodist Hospital were identified. Implantation of Heartmate 3 (HM3) Left Ventricular Assist Device (LVAD), orthotopic heart transplantation (OHT), mortality, and device removal after Impella implantation were assessed. For HM3 LVAD patients, outcomes were categorized as death, transplantation, or survival. Survival after OHT was analyzed using Kaplan-Meier analysis and compared to patients who received OHT without Impella 5.5. Cumulative incidence rates was calculated using Competing risk regression. Results: 140 patients were identified, median age 59.4 years (50.4-66.5), majority Caucasian (54%) and Black (36%). 89 (63.6%) were either bridged to advanced therapies or recovered. 52 (37.1%) underwent OHT, 21 (15%) received an HM3 LVAD, and 51 (36.4%) died post-implantation. 3 (2.1%) died post-transplant. Post-LVAD, 6 (4.3%) died, 3 (2.1%) underwent OHT, and 12 (8.6%) were alive with LVAD. 10 (7.1%) survived after Impella 5.5 removal, 2 (1.4%) went to hospice, and 1 (0.7%) was transferred to another hospital. 3 (2.1%) are currently hospitalized. Fig1a shows outcomes. Fig1b indicates death within 90 days of Impella implantation. 3-year survival of patients bridged with Impella to OHT (N=55) was 94%, comparable (p=0.27) to patients receiving OHT without Impella (N=215)(Fig 1c). Conclusion: Mortality for cardiogenic shock patients remains high. Using Impella 5.5 with a cardiac replacement strategy can salvage some patients. Long-term outcomes for patients bridged to heart transplant with Impella 5.5 are similar to those without the device. Further studies on predictors of early adverse outcomes post-implant can help mitigate risks for advanced heart failure patients in cardiogenic shock.

Abstract 4124267: Comparison of Right Ventricular Failure Prediction Models to Predict Right Ventricular Assist Device (RVAD) After HeartMate3 Implantation

Introduction: The requirement for right ventricular-assisted device (RVAD) implantation portends poor outcomes after left ventricular-assisted device (LVAD) implantation. We investigate RVF prediction models to help prediction of RV failure requiring RVAD implantation after centrifugal-flow LVAD HeartMate3 (HM3) placement. Methods: A total of 124 patients who underwent HM3 implantation at our institution from 2015-2023 were included in our analysis. We collected clinical variables used in EUROMACS RVF Risk Score (Circulation 2018), Utah Model (Am J Cardiology 2010), Michigan RVF Risk Score (JACC 2008), and CRITT (ATS 2013). Baseline scoring systems were compared with our cohort of patients with and without RVAD implantation after HM3 placement with ROC Area Under the Curve (AUC) statistical analysis. In addition, we investigated the pulmonary artery pulsatility index (PAPi) as a predictor for RV failure requiring RVAD. Results: There were 17 patients (13.7%) who underwent RVAD implantation after HM3 placement. Patients who required RVAD implant had worse survival (p = 0.037). The EUROMACS score differentiated those patients who required RVAD from those who did not (AUC: 0.66; 95% C.I: 0.51-0.81). In contrast, CRITT (AUC: 0.64; 95% C.I: 0.49-0.78), Michigan score (AUC: 0.37; 95% C.I: 0.25-0.51), and Utah (AUC: 0.53; 95% C.I: 0.40-0.68) scores did not differentiate those who required RVAD. PAPi was significantly lower in patients requiring RVAD (2.5±1.2 vs 3.9±3.0, p=0.001). Also, even as a single parameter, PAPi had an AUC of 0.63 (95% C.I: 0.50-0.76). Conclusion: RVAD implantation is associated with high early mortality. Existing RVF prediction models were not able to predict future RVAD requirements with high AUC, with the EUROMACS system having the only statistical significance. There is a lack of a strong predictive model for RV failure in HM3. Future efforts are needed to establish predictors for RV failure requiring RVAD implants in the HM3 population, especially utilizing novel hemodynamic markers such as PAPi.

Abstract 4127071: Pulmonary Artery Catheter Utilization in Cardiogenic Shock: Clinical Characteristics and Outcomes

Background: The pulmonary artery catheter (PAC) is used for hemodynamic monitoring, but its impact on patient outcomes, especially in cardiogenic shock (CS), is controversial. Several studies have shown no significant benefits and noted complications, leading to a decline in PAC use. However, PAC use appears to have increased recently in guiding management decisions in CS. Our study aims to assess the clinical characteristics and outcomes of CS patients receiving PACs versus not. Methods: We included patients with CS admitted to a tertiary academic medical center between May 2015 and December 2023. Variables were compared using Kruskal-Wallis, chi-squared, and Fisher's exact tests. Hemodynamic parameters were collected from either right heart catheterization or from a PAC. Endpoints included native heart survival to discharge, durable left ventricular assist device (LVAD) implantation, heart transplant (HTx), and 30-day and 1-year survival from discharge. Results: The study group consisted of 742 patients with CS. Of these, 385 (52%) received a PAC and 357 (48%) did not. The baseline characteristics of the two groups are shown in Table 1A . PAC patients had more severe shock, worse hemodynamics, and higher rates of temporary mechanical circulatory support (MCS) use. Hemodynamic measurements at shock onset differed, with PAC patients having higher right atrial pressures and lower cardiac index by Fick. Clinical outcomes and MCS related complications are shown in Table 1B. There was no significant difference in native heart survival at discharge, but HTx and durable LVAD implantation was higher in the PAC group. PAC placement was associated with longer hospital stays and more MCS related complications, including bleeding and hemolysis. The 30-day survival rate was similar between groups, and 1-year survival was marginally higher in the PAC group. Conclusion: PAC patients exhibited more severe clinical characteristics, longer hospital stays, higher rates of temporary MCS use and complications, durable LVAD implantation, and HTx. Short-term survival rates were similar, but 1-year survival was slightly better for PAC patients. Further studies are needed to provide clearer insights into PAC use in CS.

Abstract 4144521: Racial disparities in heart transplantation: long term graft survival and non-mortality outcomes

Background: There is conflicting evidence on whether racial disparities still exist in heart transplant (HT) outcomes, with prior studies focusing primarily on differences in short-term mortality. We examined disparities in HT survival over a longer follow-up duration alongside a broader range of post-HT outcomes. Methods: Using the United Network for Organ Sharing (UNOS) database, we evaluated adult HT recipients between 2017 and 2022 and classified each according to race as either Black, non-Hispanic White and Other. The primary outcome was graft survival and secondary outcomes included rejection, renal dysfunction, and post-transplant diabetes. Chi-squared tests were used to compare baseline clinical factors and selected outcomes by racial group. Kaplan-Meier and Cox proportional hazards analyses were performed to compare risks of the primary outcome by race. Results: Among 15,873 recipients (63% non-Hispanic White, 23% Black, 14% Other), Black recipients were more often female, less often college educated, and more often had public (vs. private) insurance. Blacks had higher use of durable ventricular assist devices (VAD) and intra-aortic balloon pump (IABP) at the time of HT. Graft survival at one year did not differ by race (91.8% for Blacks vs. 91.1% for non-Blacks), but at three years was significantly lower for Blacks (83.4%) than non-Blacks (85.7%). Blacks had higher risk of graft failure after adjustment for baseline socioeconomic status (SES) and clinical variables (HR 1.28, CI 1.17 - 1.41). Blacks also had significantly higher prevalences of acute rejection (12.4% vs. 10.2%), diabetes (10.8% vs. 7.1%), and progression of renal dysfunction at 3-years post HT (40.9% vs. 37.1%; p < 0.05 for all). Conclusions: Racial disparities in graft survival after HT remain in the contemporary era but are only evident after longer-term follow-up. These survival disparities could be mediated by concurrent disparities in shorter term outcomes such as development of acute rejection, chronic kidney disease, and new onset diabetes.

Use of Intravascular Micro-Axial Left Ventricular Assist Devices as a Bridging Strategy for Cardiogenic Shock: Mid-Term Outcomes

Objectives: Patients in cardiogenic shock (CS) may be successfully bridged using intravascular micro-axial left ventricular assist devices (M-LVADs) for recovery or determination of definitive therapy. Methods: One hundred and seven CS patients implanted with M-LVADs from January 2020 to May 2024 were divided into four groups; group-1: 34 patients (transplant); group-2: 25 patients (LVAD); group-3: 42 patients (postcardiotomy CS (PCCS)); group-4: 6 patients (decision/recovery but excluded from analysis). Multivariable logistic regression and Multivariable Coxregression models identified predictors of early -hospital and late mortality, and Odds ratios (ORs) and hazard ratios (HRs) with p < 0.05, respectively, were considered statistically significant. SPSS 29.0 and Python 3.11.1. were used for analyses. Results: Complications included device-malfunction (6%), gastrointestinal bleed (9%), long-term hemodialysis (21%), axillary hematoma requiring re-exploration (10%), heparin-induced thrombocytopenia (4%) requiring heparin therapy cessation/initiation of argatroban infusion, and non-fatal stroke (11%). Early hospital mortality included 13 patients: 2 in group-1, 1 in group-2, 10 in group-3 (p = 0.02). In the Logistic-Regression model, category of CS requiring an M-LVAD was significant (OR = 4.7, p = 0.05). Patients were followed for 4.5 years (mean follow-up was 23 ± 17 months), and 23 deaths occurred; group-1: 3 patients, group-2: 5 patients, and group-3: 15 patients (p = 0.019). At 4.5 years, actuarial survival was 90.7 ± 5.1% in group-1, 79.2 ± 8.3% in group-2, 62.8 ± 7.7% in group-3 (p = 0.01). In the Cox-Regression model, M-LVAD category (HR = 3.63, p = 0.04), and long-term postoperative dialysis (HR = 3.9, p = 0.002) emerged as predictors of long-term mortality. Conclusions: In cardiogenic shock, mid-term outcomes demonstrate good survival with M-LVADs as bridge to transplant/durable LVADs and reasonable survival with M-LVADs as a bridge to recovery following cardiotomy, accompanied by reduced ECMO usage, and early ambulation/rehabilitation.

Abstract 4118949: Factors Influencing Left Ventricular Function Recovery Following Left Ventricular Assist Device Implantation in Pediatric Dilated Cardiomyopathy: Insights from Single-Cell RNA Sequencing Analysis

Background and Objective: Heart transplantation is a recognized treatment for pediatric severe heart failure, but long-term issues necessitate alternative treatments. Some dilated cardiomyopathy (DCM) cases show left ventricular function recovery after LVAD implantation. This occurrence could lead to new treatments, but mechanisms are unclear. This study explores preoperative molecular factors interacting with LVAD's effects using single-cell transcriptomics on clinical samples. Methods: Twenty-five pediatric DCM patients underwent Berlin Heart EXCOR (BHE) implantation at our institution since 2013. Those with left ventricular ejection fraction (LVEF) improving by >20% were in the Recovery group (R), others in Non-Recovery (NR). Single-cell RNA-sequence was performed on myocardial tissue from six patients (three per group). Differential gene expression and pathway analysis were conducted for each cell type. Findings were validated by comparing them with histological evaluation or clinical examination in all 25 cases. Results: R: 10 patients; NR: 15. R's weight was 6.3 kg, NR's 9.9 kg (p=0.049); LVEF: R 23%, NR 16.5% (p=0.61). In pseudobulk analysis of cardiomyocytes, upregulated genes in R included NPPB, MYL7, PCDH9. KEGG analysis indicated activation of Tight Junction and ECM receptor pathways in R. In fibroblasts, major extracellular matrix proteins were higher in R, GSL gene expression in NR. Plasma Brain Natriuretic Peptide (BNP) at BHE implantation was significantly higher in R; 2913 [1836-3990 (95% CI)] vs 1278 [667-1888] pg/ml (Image1,2). No differences in tissue fibrosis rates were found between the groups. Conclusion: Alterations in gene expression patterns in some cell clusters, including cardiomyocytes, may contribute to left ventricular function recovery post-BHE implantation in pediatric DCM patients. Plasma BNP levels correlated with gene expression alterations, suggesting both a potentially protective effect on cardiomyocytes and a useful marker of LV functional recovery. Further validation of these candidate genes may elucidate intracellular molecular mechanisms.

Abstract 4144514: Human Immunodeficiency Virus Associated Cardiomyopathy- A Rare Cause of Heart Failure With Reduced Ejection Fraction in Era of Highly Active Antiretroviral Therapy

Introduction: Human Immunodeficiency Virus Associated Cardiomyopathy (HIVAC) is characterized by left ventricular (LV) systolic or diastolic dysfunction with or without LV dilatation and heart failure symptoms. The introduction of antiretroviral therapy (ART) has changed the fulminant systolic heart failure presentation of HIV myocarditis to diastolic heart failure. We present a unique case of dilated cardiomyopathy in a young patient without advanced HIV illness which has rarely been documented in the literature. This is a rare presentation of HIVAC in the post-ART era. Case Report: A 32-year-old male with a past medical history (PMH) of the human immunodeficiency virus (HIV) presented with complaints of new onset worsening shortness of breath and lower extremity edema for four weeks. He was diagnosed with HIV seven years ago and was not compliant with ART. Laboratory testing showed a cluster of differentiation 4 (CD4) 823 and HIV load 2550. Myocarditis was ruled out by normal troponin levels and no new changes on the electrocardiogram (ECG). Transthoracic echocardiogram (TTE) showed dilated left ventricle (LV), LV global hypokinesis, LV ejection fraction (LVEF) 10-15%, dilated right ventricle, biatrial dilation, moderate to severe mitral regurgitation, severe tricuspid regurgitation, pulmonary artery (PA) systolic pressure 73 mmHg and no pericardial effusion. Coronary angiography was negative for coronary artery disease (CAD). The patient was started on carvedilol and outpatient evaluation for a left ventricular assistance device. Discussion: Systolic dysfunction in patients with HIVAC carried a poor prognosis in the pre-ART era and was common in patients with elevated c-reactive protein (CRP), tobacco use, and previous myocardial infarction (MI). After the advent of ART, systolic dysfunction is rare and replaced by diastolic cardiomyopathy in the setting of ART use. Diagnosis is usually by excluding other etiologies and biopsy is not necessarily required. Management is usually guideline-directed medical therapy (i.e. beta blocker, renin-angiotensin-aldosterone antagonists, sodium-glucose cotransporter-2) and device-based therapy but there is still data lacking to assess its benefit.