Device Thrombosis Research Articles

One-year Outcomes of XIENCE Skypoint 48-mm Drug-Eluting Stents in Long Coronary Lesions: The SPIRIT 48 Trial.

Diffuse coronary artery disease may need multiple overlapping stents, associated with less favorable outcomes than those of a single stent. The availability of longer stents can circumvent the need for overlapping stents in long lesions. This prospective, single-arm, SPIRIT 48 trial evaluated the safety and effectiveness of Abbott's next-generation drug-eluting stent, XIENCE Skypoint 48, in patients with coronary artery disease with long de novo native coronary lesions. SPIRIT 48 enrolled 107 patients at 25 sites in 3 countries. Patients were required to have 1 target lesion treated with XIENCE Skypoint 48 (lesion length of >32.0 mm and ≤44.0 mm). The primary end point was target lesion failure (TLF; composite of cardiac death, target vessel-related myocardial infarction, or clinically indicated target lesion revascularization) at the 1-year compared with a prespecified performance goal of 20%, established through historical control data. This study recently completed its 1-year follow-up. XIENCE Skypoint 48 was implanted in 105 patients with a device success rate of 97.2%. SPIRIT 48 met its primary end point, with a TLF rate of 5.7%, and the upper bound of 95% CI at 9.5% (<performance goal of 20%). This was associated with a low rate of 5.8% (6/104 patients) for cardiac death/all myocardial infarction at 1 year. Definite or probable device thrombosis at 1 year occurred in only 1 subject (1.0%). Primary end point data obtained at the 1-year follow-up from the SPIRIT 48 trial present strong evidence supporting the deliverability, safety, and effectiveness of XIENCE Skypoint 48 mm drug-eluting stent in treating long de novo coronary lesions.

BIO29: A Microfluidic Model Of Extracorporeal Circuit Thrombosis

Purpose: Cardiovascular medical devices such as extracorporeal membrane oxygenation (ECMO) machines are critical for the treatment and management of cardiorespiratory illnesses. However, blood contact with medical device biomaterials causes dangerous blood clot formation (thrombosis). In ECMO, blood clots can grow large enough to occlude circuitry and fail the device, or clots may dislodge and potentiate stroke and embolism in patients. While medical device thrombosis is clinically managed with systemic anticoagulation, thrombosis and its associated complications still exist, and anticoagulation frequently worsens patient outcomes by causing severe bleeding. There remains an urgent need to understand the mechanisms of biomaterial thrombosis and develop thromboresistant biomaterials. We hereby demonstrate a novel biomaterial thrombosis on-a-chip model system for real-time, high-throughput evaluation of ECMO thrombosis. Methods: Our study combines computational fluid dynamics (CFD) and microfluidic technology to design in vitro models with customizable, clinically relevant biomaterials and flow conditions, which are two key factors influencing thrombus formation. ANSYS Fluent was used to model the flow parameters within ECMO tubing and tubing-connector junctions (TCJ). Microfluidic devices were fabricated using standard photolithography and soft lithography with unplasticized polyvinylchloride (UPVC) and polycarbonate (PC), replicating ECMO tubing and TCJ respectively. Biomaterial thrombosis was visualized in real-time via confocal microscopy, and analyzed as the total fluorescent area of platelet adhesion (CD41-FITC) and human fibrin/ogen (AF647) accumulation. Results: CFD revealed that shear rates of 500 – 5000 s-1 and decelerating flow regimes are relevant to ECMO tubing thrombosis. Microfluidic evaluation at such conditions showed that compared to the low platelet adhesion observed at continuous high shear (3000 s-1) (340 ± 266 µm2), platelet adhesion increased by 16-fold at continuous low shear (1000 s-1) (5510 ± 3631 µm2), increased 5-fold at deceleration into high shear (1703 ± 598 µm2), and increased 2.7-fold at stagnant into high shear conditions (912 ± 308 µm2). These results may be used to guide clinical practice and ECMO redesign to minimize low, decelerating shear. Conclusion: We have developed a model system capable of evaluating biomaterial thrombosis at tailorable, clinically relevant biomaterial and flow combinations. Additionally, this system may be used to test novel anti-thrombotic biomaterials or patient-specific blood-biomaterial compatibility. Ultimately, this model will improve ECMO treatment efficacy by advancing the field’s knowledge in scientific mechanisms underlying biomaterial thrombosis, inform clinicians of thrombotic flow regimes which should be minimized, and identify thrombotic biomaterial and flow combinations to guide bioengineers to design the next generation of safer ECMO.Figure 1. A microfluidic device incorporating extracorporeal circuit biomaterials is used to visualize thrombus formation under clinically relevant flow.

Left Atrial Appendage Occlusion Strengths and Weaknesses of the Lobe-Only Occluder Concept in Theory and in Practice

Left atrial appendage closure aims to eliminate the stasis component of Virchow triad by eliminating a cul-de-sac that favors thrombosis, particularly when atrial contractility becomes inefficient, such as in atrial fibrillation. Left atrial appendage closure devices have a common objective of sealing the appendage completely, with device stability and avoidance of device thrombosis. Two main device designs have been used to perform left atrial appendage closure: those that use a pacifier design (lobe+disk) and those that use a plug (single lobe) design. This review highlights the potential features and benefits of the single-lobe devices.

P112 CLINICAL OUTCOMES OF LEFT ATRIAL APPENDAGE OCCLUSION WITH CONSCIOUS SEDATION WITHOUT ANESTHESIOLOGIST ON SITE: RESULTS FROM A MULTICENTER RETROSPECTIVE STUDY

Abstract Background Left atrial appendage (LAA) occlusion is an important therapeutic option to prevent cardioembolic stroke in patients with atrial fibrillation (AF) with contraindications for oral anticoagulation (OAC). It is usually performed with transesophageal echocardiography (TOE) under general anesthesia (GA). In this retrospective study we present a multicenter experience of LAA occlusion performed with conscious sedation (CS) without anesthesiologist on site. Methods We collected all the LAA occlusion procedures performed from October 2018 to May 2022. All the included patients underwent the procedure for OAC intolerance mainly due to bleeding with irreversible causes. All the procedures were performed with Watchman or Amulet LAA occluders under TOE and fluoroscopy guidance by two expert interventional cardiologists without anesthesiologist on site. CS was performed with a combination of midazolam and fentanyl. Results One hundred and fifteen patients (age 76.4 ± 7.6 year) with non–valvular AF (median CHA2DS2Vasc 4.4 ± 1.4) were included in the study. CS was performed using midazolam (mean dose 5.9 ± 2.1 mg), adding fentanyl (mean dose 52.8 ± 19.6 mcg) in case of poor tolerance of the procedure despite midazolam. Acute procedural success rate was of 99.2%. One patient suffered a cardiac tamponade, urgent necessity of cardiac surgery and died 5 days after procedure. Two patients (2.6%) had anemia with need for transfusion after interventions. A patient (0.8%) suffered from oropharynx hematoma due to TOE. One case (0,8%) of vascular access site pseudoaneurysm occurred. One case (0.8%) of device thrombosis at 3 months TOE follow–up was reported. One procedure (0.8%) result in large leak device (³5 mm), confirmed at TOE follow–up performed at 3 months follow–up. No thromboembolic complications were reported. One hundred and fourteen (99.2%) patients stopped dual antiplatelet therapy within 12 months. In a follow–up of 10 ± 9 months one case of stroke (0.8%) and one case (0.8%) of transient ischemic attack (TIA) occurred. Conclusion LAA occlusion performed under CS and without the presence of anesthesiologist in cath–lab appear to be safe and effective. It can be an attractive alternative to (GA) because of lower medical staff needed and organizational effort required. In our retrospective study the success rate and the incidence of adverse events appear to be comparable with those of previous studies on the topic of LAA occlusion

P299 WATCHMAN DEVICE THROMBOSIS FOLLOWING THE PERCUTANEOUS CLOSURE OF THE LEFT ATRIUM APPENDAGE: A "CUL–DE–SAC" IN THE ANTITHROMBOTIC STRATEGY

Abstract Background The percutaneous closure of the left atrium appendage (LAA) is a valuable therapeutic tool in patients with atrial fibrillation (AF) who have contraindications to anticoagulant drugs. However, the procedure can lead to complications and the device positioning determines a risk of thrombosis that can‘t be underestimated, especially during the first period from the intervention. Clinical Case In this report we propose the case of a 72 years old man in chronic therapy with NOAC (non–vitamin K antagonist oral anticoagulants) for a paroxysmal AF (CHA2DS2–VASC = 3), that presented intracranial hemorrhage after 3 years due to a cerebral arteriovenous malformation. This condition represents an absolute contraindication to anticoagulant therapy, because of the high hemorrhagic risk, and led to the percutaneous device positioning (WATCHMAN 24 mm) for LAA closure. After the implantation procedure we started a single antiplatelet therapy (SAPT) with clopidogrel 75 mg for 6 months. At one month follow–up a trans–esophageal echocardiogram (TEE) showed the presence of a swinging samll trombotic formation (4x2,5 mm) attached to the device. At that time antithrombotic therapy with enoxaparin 6000 IU was started, in addition to SAPT. Ten days later, another TEE showed the thrombus resolution and we decided to continue with clopidogrel alone. No relevant clinical events were observed to the subsequent follow–up. Discussion Current recommendations suggest double antiplatelet therapy (DAPT) for 1–6 months followed by SAPT, in patients who have absolute contraindication to anticoagulant drugs, or SAPT for at least 1 month in those who have an extreme hemorrhagic risk. LAA closure device thrombosis affects 3% of patients and represents an independent predictor of cerebral ischemic events, according to various registers and meta–analyses. This event determines an indication to anticoagulant therapy in patients who would have an absolute contraindication, creating a difficult management that assume clinical relevance. In our experience a 10 days therapy with heparin added to SAPT led to thrombosis resolution. However the therapeutic management of these complications is currently not standardized and more studies are needed.

5-Year Outcomes After Bioresorbable Coronary Scaffolds Implanted With Improved Technique

BackgroundBioresorbable vascular scaffolds (BVS) were designed to improve late event-free survival compared with metallic drug-eluting stents. However, initial trials demonstrated worse early outcomes with BVS, in part due to suboptimal technique. In the large-scale, blinded ABSORB IV trial, polymeric everolimus-eluting BVS implanted with improved technique demonstrated noninferior 1-year outcomes compared with cobalt chromium everolimus-eluting stents (CoCr-EES). ObjectivesThis study sought to evaluate the long-term outcomes from the ABSORB IV trial. MethodsWe randomized 2,604 patients at 147 sites with stable or acute coronary syndromes to BVS with improved technique vs CoCr-EES. Patients, clinical assessors, and event adjudicators were blinded to randomization. Five-year follow-up was completed. ResultsTarget lesion failure at 5 years occurred in 216 (17.5%) patients assigned to BVS and 180 (14.5%) patients assigned to CoCr-EES (P = 0.03). Device thrombosis within 5 years occurred in 21 (1.7%) BVS and 13 (1.1%) CoCr-EES patients (P = 0.15). Event rates were slightly greater with BVS than CoCr-EES through 3-year follow-up and were similar between 3 and 5 years. Angina, also centrally adjudicated, recurred within 5 years in 659 patients (cumulative rate 53.0%) assigned to BVS and 674 (53.3%) patients assigned to CoCr-EES (P = 0.63). ConclusionsIn this large-scale, blinded randomized trial, despite the improved implantation technique, the absolute 5-year rate of target lesion failure was 3% greater after BVS compared with CoCr-EES. The risk period for increased events was limited to 3 years, the time point of complete scaffold bioresorption; event rates were similar thereafter. Angina recurrence after intervention was frequent during 5-year follow-up but was comparable with both devices.(Absorb IV Randomized Controlled Trial; NCT02173379)

Left Atrial Appendage Closure Device Thrombosis Despite Therapeutic Anticoagulation with Rivaroxaban

Left Atrial Appendage Closure Device Thrombosis Despite Therapeutic Anticoagulation with Rivaroxaban

Bioinspired Approaches to Engineer Antithrombogenic Medical Devices for Vascular Intervention.

Medical devices form a critical component of health care systems for treating and maintaining patient health. However, devices exposed to blood are prone to blood clotting (thrombosis) and bleeding complications leading to device occlusion, device failure, embolism and stroke, and increased morbidity and mortality. Over the years, developments in innovative material design strategies have been made to help reduce the occurrence of thrombotic events on medical devices, but complications persist. Here, we review material and surface coating technologies that have taken bioinspiration from the endothelium to reduce medical device thrombosis, either by mimicking aspects of the glycocalyx to prevent adhesion of proteins and cells to the material surface or mimicking the bioactive function of the endothelium through immobilized or released bioactive molecules to actively inhibit thrombosis. We highlight newer strategies that take inspiration from multiple aspects of the endothelium or are stimuli responsive, only releasing antithrombotic biomolecules when thrombosis is triggered. Emerging areas of innovation target inflammation to decrease thrombosis without increasing bleeding, and interesting results are coming from underexplored aspects of material properties, such as material interfacial mobility and stiffness, which show that increased mobility and decreased stiffness are less thrombogenic. These exciting new strategies require further research and development before clinical translation, including consideration of longevity, cost, and sterilization, but show capacity for the development of more sophisticated antithrombotic medical device materials.

(332) Left Ventricular Functional Improvement is Associated with Lower Rates of Device Thrombosis in Patients on Durable Mechanical Circulatory Support

(332) Left Ventricular Functional Improvement is Associated with Lower Rates of Device Thrombosis in Patients on Durable Mechanical Circulatory Support

Left ventricular functional improvement appears to contribute to lower rates of device thrombosis in patients on durable mechanical circulatory support

By unloading the failing heart, left ventricular (LV) assist devices (LVADs) provide a favorable environment for reversing adverse structural and functional cardiac changes. Prior reports have suggested that an improved native LV function might contribute to the development of LVAD thrombosis. We used the Interagency Registry for Mechanically Assisted Circulatory Support and found that LV functional improvement is associated with a lower risk for device thrombosis. The risk for cerebrovascular accident and transient ischemic attack was comparable across post-LVAD LV function subgroups, while the risk of hemolysis was lower in subgroups of patients with better LV function on LVAD support.

Study protocol for neuromuscular stimulation for rehabilitation after general and vascular surgery: a pilot randomised clinical study

ObjectivesTo investigate the acceptability and safety of neuromuscular stimulation (NMES) as an adjunct for rehabilitation after vascular and general surgery.Methods and analysisProspective, single-centre, single-blind, parallel group, randomised controlled study. This...

Left ventricular assist device exchange: a review of indications, operative procedure, and outcomes.

The use of left ventricular assist devices (LVADs) is intended to treat patients with end-stage heart failure. Owing to technological advances, these devices are becoming more durable. However, LVADs may need to be exchanged when complications arise and heart transplantation is not possible. Indications for LVAD exchange (LVADE) include device thrombosis, device infections, and pump component failure. LVADE has historically been associated with a high risk of morbidity and mortality. In this review, we discuss the indications of LVADE, the decisional and technical aspects during surgery, and outcomes.

Impact of preoperative mitral regurgitation on left ventricular assist device patients: propensity score-matched analysis of the EUROMACS dataset.

Mitral regurgitation (MR) is frequently observed in patients undergoing left ventricular assist device implantation. We investigated the impact of preoperative MR on left ventricular assist device patients. A retrospective propensity score-matched analysis of adult patients enrolled in the EUROMACS registry between 1 January 2011 and 30 November 2021 was performed. Patients were divided into 2 groups according to the grade of preoperative MR: none-to-mild (MR 0-II) or moderate-to-severe (MR III-IV). Following 1:1 propensity score matching, each group consisted of 914 patients. Incidence of postoperative temporary right ventricular support, reoperation for bleeding and dialysis was similar. MR III-IV demonstrated shorter median intensive care unit stay [14 days (6; 27.8) vs 10 days (5; 22), P = 0.004] and ventilation time [72 h (22, 320) vs 31 h (18, 150), P < 0.001]. Mortality was lower for MR III-IV patients [subdistribution hazard ratio: 0.66, 95% confidence interval (CI): 0.59-0.73, P < 0.001]. The 1-year survival was 68.1% (95% CI: 65.1-71.3%) in MR 0-II and 75% (95% CI: 72.1-78%) in MR III-IV. A lower incidence of total complications [odds ratio (OR): 0.93 (0.89-0.98), P = 0.003] and trend towards a lower risk of neurological dysfunction (subdistribution hazard ratio: 0.79; 95% CI: 0.61-1.01, P = 0.063) and sustained ventricular tachycardia [OR: 0.93 (0.54-1.03), P = 0.074] were demonstrated for MR III-IV. The risk of fatal stroke and pump thrombosis was similar. Moderate-to-severe MR in patients undergoing left ventricular assist device implantation is associated with better mid-term survival and lower incidence of total major adverse events and complications. The incidence of severe postoperative complications including fatal stroke and device thrombosis was similar.

Safety and Efficacy of Everolimus-Eluting Bioresorbable Vascular Scaffold Versus Second-Generation Drug-Eluting Stents in Real-World Practice.

The risk of device thrombosis and device-oriented clinical outcomes with bioresorbable vascular scaffold (BVS) was reported to be significantly higher than with contemporary drug-eluting stents (DESs). However, optimal device implantation may improve clinical outcomes in patients receiving BVS. The current study evaluated mid-term safety and efficacy of Absorb BVS with meticulous device optimization under intravascular imaging guidance. The SMART-REWARD and PERSPECTIVE-PCI registries in Korea prospectively enrolled 390 patients with BVS and 675 patients with DES, respectively. The primary endpoint was target vessel failure (TVF) at 2 years and the secondary major endpoint was patient-oriented composite outcome (POCO) at 2 years. Patient-level pooled analysis evaluated 1,003 patients (377 patients with BVS and 626 patients with DES). Mean scaffold diameter per lesion was 3.24 ± 0.30 mm in BVS group. Most BVSs were implanted with pre-dilatation (90.9%), intravascular imaging guidance (74.9%), and post-dilatation (73.1%) at proximal to mid segment (81.9%) in target vessel. Patients treated with BVS showed comparable risks of 2-year TVF (2.9% vs. 3.7%, adjusted hazard ratio [HR], 1.283, 95% confidence interval [CI], 0.487-3.378, P = 0.615) and 2-year POCO (4.5% vs. 5.9%, adjusted HR, 1.413, 95% CI, 0.663-3.012, P = 0.370) than those with DES. The rate of 2-year definite or probable device thrombosis (0.3% vs. 0.5%, P = 0.424) was also similar. The sensitivity analyses consistently showed comparable risk of TVF and POCO between the 2 groups. With meticulous device optimization under imaging guidance and avoidance of implantation in small vessels, BVS showed comparable risks of 2-year TVF and device thrombosis with DES. ClinicalTrials.gov Identifier: NCT02601404, NCT04265443.

369: SAFETY AND EFFICACY OF ARGATROBAN MONITORING USING A FIXED ACTIVATED PARTIAL THROMBOPLASTIN TIME

Introduction: The argatroban package insert recommends monitoring for both safety and efficacy with an activated partial thromboplastin time (aPTT) goal range, created by multiplying the patient’s baseline aPTT by 1.5 and 3, not to exceed 100 seconds. If a baseline aPTT is unavailable, The University of Kansas Health System (TUKHS) recommends using a fixed aPTT goal range of 45-85 seconds. The purpose of this study was to evaluate the safety and efficacy of using a fixed aPTT goal of 45-85 seconds as compared to a patient-specific aPTT goal. Methods: This was a retrospective, single-center case control chart review of argatroban infusions titrated to a fixed aPTT range of 45-85 seconds versus a calculated patient-specific aPTT range. Patients 18 years or older were included if they received an argatroban infusion. Patients were excluded from the study if they received argatroban for less than 1 hour or if the indication for argatroban infusion was percutaneous coronary intervention or left ventricular assist device thrombosis. The primary outcome was the percent of aPTT levels within the range of 45-85 seconds for patients receiving argatroban. Secondary outcomes were the percent of aPTT values within the prescribed range and bleeding or thrombotic events. Results: A total of 146 patients were included in this study, of which 59 patients had a fixed aPTT goal range and 87 patients had a patient-specific aPTT goal range. Both groups had similar percentages of aPTT values within the 45-85 second range, 74.1% and 66.5% respectively (p = 0.09). Four patients (6.7%) with a fixed aPTT goal range and 6 patients (6.8%) with a patient-specific goal range experienced bleeding events (p = 0.978), and no patients experienced thrombotic events. Conclusions: The results of this study showed that regardless of how the target monitoring parameter was ordered, there was no statistically significant difference in the percent of aPTT values within the 45-85 second aPTT goal range. There was also no significant difference in bleeding or thrombotic events for patients among both groups. The results of this study may be used to implement a change to argatroban monitoring at TUKHS to a fixed aPTT goal range of 45-85 seconds to promote consistency in the ordered goal ranges without impacting patient safety.

Results of non-elective withdrawal of continuous-flow left ventricular assist devices in selected patients

Protocols have been developed to identify patients for elective withdrawal of continuous-flow left ventricular device (cfLVAD) support. However, little is known about non-elective explantation or decommissioning of cfLVADs. A retrospective analysis of all patients who underwent left ventricular assist device (LVAD) explantation or decommissioning at a single center between 2002 and 2021 was performed. Sixty-one patients underwent withdrawal of a cfLVAD (HeartMate II [Abbott] n=17, HeartMate 3 [Abbott] n=2, HeartWare HVAD [Medtronic] n=36, INCOR [Berlin Heart] n=6). The median follow-up after withdrawal was 1,039 days. The survival at 5 years was 76.1% (95% CI: 64.2%-95.2%). Predictors of worse outcomes in univariate regressive analysis were the duration of heart failure and the age at LVAD implantation. Of the 61 patients, 40 underwent elective withdrawal following a specific protocol. The other twenty-one patients underwent non-elective withdrawal of the cfLVAD because of device infection (n=12), device thrombosis (n=6), device malfunction (n=2) or due to acute intracerebral bleeding (n=1), also with an excellent survival at 5 years of 81.3%. (95% CI: 63.8-1). The withdrawal was performed in these patients even though they did not fulfill established criteria for successful explantation or decommissioning like clinical stability (n=21), left ventricular end-diastolic diameter ≤ 55 mm (n=3), performance of right heart catheterization (n=6), or pulmonary artery wedge pressure ≤ 15 mm Hg (n=3). Non-elective withdrawal is possible in selected patients after discussion in a team of experienced cardiac surgeons, cardiologists, technicians, and VAD coordinators. The appropriate preoperative assessment before decommissioning or explantation of a cfLVAD warrants further investigation.

Safety, efficacy, and clinical outcomes of transcatheter tricuspid valve replacement: One-year follow-up.

The aim was to evaluate the safety and efficacy of TTVR in patients with severe TR at the 1-year follow-up. This project was a single-center, observational study. From September 2020 to May 2021, 15 patients with severe or extremely severe TR at high risk of traditional surgery were enrolled. All patients had preoperative imaging assessments to evaluate the tricuspid valve and the anatomy of the right heart. All patients were planned to treated with the LuX-Valve (Ningbo Jenscare Biotechnology, Ningbo, China). The LuX-Valve was implanted under the intraoperative guidance of TEE and X-ray fluoroscopy. Data were collected at baseline, before discharge, and at 30 days, 6 months, and 1 year postoperatively. The LuX-Valves were successfully implanted in all 15 patients. TR was significantly reduced to ≤ 2 +. One patient died on postoperative day 12 of a pulmonary infection that was considered unrelated to the procedures or the devices. The remaining 14 patients (100.0%) reached the primary end point. One patient (7.1%) was rehospitalized during 1-year follow-up because of device thrombosis. The number of patients who survived at 1 year with New York Heart Association (NYHA) functional class II was higher than that before TTVR (11/14 vs. 0/15, P = 9.11 × 10-4). Patients with peripheral edema and ascites decreased from 100.0 to 46.7% at baseline to 28.6% and 14.3% at 1 year (P = 1.57 × 10-3 and 2.53 × 10-2). TTVR is associated with RV remodeling, increased cardiac output, and improvement in NYHA functional class. Using the LuX-Valve for TTVR to treat patients with severe TR is a feasible and relatively safe method with reliable clinical results. Further studies are needed to determine long-term outcomes.

Abstract 14750: Mechanical Circulatory Support Devices Among Patients With Familial Dilated Cardiomyopathy

Introduction: With increasing disease recognition and widespread availability of genetic testing, it is important to characterize the clinical outcomes and prognosis among familial dilated cardiomyopathy (DCM) patients with stage D heart failure requiring a mechanical circulatory support device (MCSD). INTERMACS (INTEragency Registry for Mechanical Assisted Circulatory Devices) was examined to assess the clinical characteristics and outcomes of familial DCM patients who received an MCSD. Methods: DCM patients who received an MCSD between June 2005-December 2017 were classified according to their etiology. The primary outcome was death (with heart transplant as a competing risk) and the secondary outcome was heart transplant (with death as a competing risk). Multivariable-adjusted Cox regression analyses were used to assess the risk of study outcomes across DCM etiologies. Results: Among 19,928 DCM patients, 8,622 (43.3%), 7,091 (35.6%), 568 (2.9%), and 3,647 (18.3%) had ischemic DCM, idiopathic DCM, familial DCM, and DCM due to other causes respectively. Familial DCM patients had the lowest median age at implantation [46 (34, 56) years] compared with other DCM etiologies. Bridge to transplant was the most common device strategy (78.4%) in the familial DCM group (45.6% were listed and an additional 32.8% were eligible for a heart transplant). Familial DCM patients had the lowest adverse events of bleeding, device thrombosis, infection, and respiratory failure post-MCSD implantation. Over a median follow-up of 1.0 (0.4, 2.0) years, familial DCM patients had the lowest risk of death [HR adj : 0.68 (95% CI: 0.55-0.83)] and the highest likelihood of heart transplantation [HR adj : 1.47 (95% CI: 1.28-1.69)] compared with the other DCM groups. Conclusions: Among DCM patients receiving MCSDs, familial DCM patients had the lowest adverse events, the lowest risk of death, and the highest likelihood of heart transplantation, compared with other DCM etiologies.

Abstract 12777: The Lingering Snag in Era of Mechanical Pumps: A Case of Acute Pump Thrombosis Immediately After Heartmate 3 Implantation

Background: Pump thrombosis (PT) remains a dreaded complication of left ventricle assist device (LVAD) implantation. PT immediately after HeartMate 3 (HM3) implantation is rare but should be kelp in mind if early low flow alarms are noted. Case: A 57-year-old male with ischemic cardiomyopathy, Stage D heart failure (LVEF ~20%), INTERMACS category 3 on 5mcg/kg/min Dobutamine drip underwent advanced heart failure therapy evaluation and was deemed suitable candidate for LVAD implant. His ECHO showed LVIDD 6.04 cm and LV Diastolic Volume Index 122 mL. He underwent HM3 implantation via left anterior thoracotomy and upper-hemi sternotomy on 5/24/2022. Surgery was successful and the patient was taken off bypass. Pre-implant some LV trabeculations and debris were removed. However, less than 1 hour from being off bypass, the low flow alarms began which did not resolve after volume and blood pressure optimization. No RV failure was noted on TEE. Decision was made to re-open the sternum. Upon exploration, no compression of the outflow graft was noted, and inlet cannula was not mispositioned. Inspection of LVAD inlet and outlet cannula showed significant amount of white thrombus (Figure 1) and device was ultimately exchanged. Thrombus was confirmed on histopathological analysis. Post-operatively no low flow alarms were noted after pump exchange. Factor V Leiden screen and protein C activity were normal and Antithrombin 3 was falsely low (due to recent thrombus) on post-op day 1. Discussion: This is the second case of HM 3 device thrombosis within 1 hour of implant in the literature. Most of the earlier reported cases were on post-Op Day 3. The etiology of PT is unknown and further investigation is required to elucidate the same. This case will create awareness among physicians to keep PT in differentials when low flow alarms are encountered immediately post-op despite volume and BP optimization.

Abstract 14511: A Single Center Experience With the Safety and Feasibility of Concomitant Atrial Fibrillation Ablation and Left Atrial Appendage Occlusion: Six-Month Outcomes

Introduction: Given the procedural similarities between atrial fibrillation (AF) catheter ablation and left atrial appendage (LAA) occlusion, interest has grown over recent years in combining them into a single concomitant procedure as a strategy for rhythm control and stroke prevention. We report on the short-term outcomes of the combined procedure in a single center case series. Methods and Results Data was gathered by retrospective chart review. Between June 2015 to August 2021, 242 patients (61% male, mean age 72 ± 8, CHA2DS2-VASc 3.8 ± 1.3, HAS-BLED 2.5 ± 1.1) underwent concomitant AF ablation and LAA occlusion with the Watchman device. Successful occlusion occurred in 224 patients (93%) with a mean procedural time of 182 ± 76 minutes, mean maximum compression of 25 ± 5.5%, and a median number of 1 device. Reasons for aborting included anatomic difficulties (83%), the presence of sludge or thrombus in the LAA (11%), and edema at the site of ablation in only 1 case (6%). Peri-procedural complications included 2 cases of left atrial appendage perforation requiring surgical device extraction, 1 stroke, 6 cases of pericarditis, and 4 vascular access site complications including 1 retroperitoneal bleed, 1 superficial hematoma, 1 persistent bleeding requiring admission, and 1 arteriovenous fistula. 205 patients (92%) had appropriate follow-up within 6 months. Anticoagulation was successfully discontinued in 90 patients (44%) at 3 months, and 178 patients (87%) at 6 months. Antiarrhythmics were discontinued in 25 patients at 3 months (12%) and 35 patients at 6 months (17%). Ninety-day complications included 12 cases of gastrointestinal bleeding, 4 cases of genitourinary bleeding, 3 cases of volume overload, 2 cases of epistaxis, and 1 intracerebral hemorrhage. All patients with repeat imaging (95%) over a mean follow-up duration of 93 days remained with adequate occlusion, with 5 cases of device thrombosis (2%). Conclusion In conclusion, the combined procedures of catheter ablation for AF and LAA occlusion with the Watchman device appears to be safe and feasible. Further data are needed on long-term outcomes of arrhythmia recurrence, bleeding, and thromboembolic events to determine which patients might benefit most from the hybrid approach.