Pump Thrombosis Rates Research Articles

Shared care for patients with a left ventricular assist device: a scoping review.

Left ventricular assist devices (LVADs) are increasingly implanted in patients with advanced heart failure. Currently, LVAD care is predominantly concentrated at specialized tertiary care hospitals. However, the increasing workload and logistical burden for implanting centres pose significant challenges to accessing care for individual patients in remote areas. An emerging approach to LVAD patient management is the use of a shared care model (SCM), which facilitates collaboration between implanting centres and local non-implanting hospitals. This scoping review explores and synthesizes the current scientific evidence on the use of SCMs in LVAD care management. Eligible studies were identified in EMBASE, PubMed MEDLINE, Web of Science, Cochrane and Google Scholar. Findings were synthesized in accordance with PRISMA-ScR guidelines. Of the 950 records screened, five articles met the inclusion criteria. Four review articles focused on the proposed benefits and challenges of using SCMs. Main benefits included improved patient satisfaction and continuity of care. Important challenges were initial education of non-implanting centre staff and maintaining competency. One prospective study showed that absence of LVAD-specific care was associated with impaired survival and higher rates of pump thrombosis and LVAD-related infections. The use of SCMs is a promising approach in the long-term management of LVAD patients. However, sufficient evidence about the impact of SCMs on patients and the healthcare system is not currently available. Standardized protocols based on prospective studies are needed to develop safe and effective shared care for LVAD patients.

Comparing left ventricular assist device inflow cannula angle between median sternotomy and thoracotomy using 3D reconstructions.

Left ventricular assist device (LVAD) implantation via thoracotomy has many potential advantages compared to conventional sternotomy, including improved inflow cannula (IFC) positioning. We compared the difference in IFC angles, postoperative, and long-term outcomes for patients with LVADs implanted via thoracotomy and sternotomy. A single-center, retrospective analysis of 14 patients who underwent thoracotomy implantation was performed and matched with 28 patients who underwent sternotomy LVAD implantations for a total of 42 patients. Inclusion required a minimum LVAD support duration of 30 days and excluded concomitant procedures. A postoperative CT-chest was used to measure the angle the between the IFC and mitral valve in two-dimensions and results were compared with three-dimensional reconstruction using the same CT chest. Outcome data were extracted from medical records. There was no significant difference in gender, INTERMACS score, BMI, or age between the two groups. Median cardiopulmonary bypass time was longer in the thoracotomy group compared to the sternotomy group, 107min (86-122) versus 76min (56-93), p < 0.01. 3D reconstructions revealed less deviation of the IFC away from the mitral valve in devices implanted via thoracotomy compared to sternotomy, median (IQR) angle 16.3° (13.9°-21.0°) versus 23.2° (17.9°-26.4°), p < 0.01. Rates of pump thrombosis, stroke, and gastrointestinal bleeding were not significantly different. Devices implanted via thoracotomy demonstrated less deviation away from mitral valve. However, there was no difference in morbidity between the two approaches. 3D reconstruction of the heart is an innovative technique to measure angulation and is clinically advantageous when compared to 2D imaging.

Triple Antithrombotic Therapy in Patients With Left Ventricular Assist Devices.

Data on the efficacy and safety of the combination of warfarin and dual-antiplatelet therapy compared with warfarin and mono-antiplatelet therapy (MAPT) in patients with left ventricular assist devices (LVAD) remains scarce. Single-center study of 130 consecutive patients with durable LVAD. Baseline demographics, antithrombotic and antiplatelet regimen, and outcomes were compared between patients receiving warfarin plus dual-antiplatelet therapy (Group 1) and warfarin plus MAPT (Group 2). Antiplatelet therapy was assessed at hospital discharge post-LVAD implant and included aspirin, clopidogrel and dipyridamole. Outcomes at 1-year were assessed in each group. All patients were on aspirin and warfarin. No significant differences with regards to age, gender or ethnicity were noted at baseline between the two groups. Group 1 was more likely to have higher lactate dehydrogenase LDH levels at discharge and a history of stroke. No significant differences in international normalized ratio INR, hemoglobin or hematocrit were noted at discharge. During the study period, 48 patients had gastrointestinal bleeding events: 28 of 68 (41.2%) in Group 1 vs 20 of 62 (32.2%) in Group 2 (P = 0.293). At 1year, no statistically significant differences were noted in gastrointestinal bleeding (Group 1=27.90% vs Group 2 = 25.80, P = 0.784), ischemic stroke (Group 1 = 8.8% vs group 2 = 6.5%, P = 0.612), hemorrhagic stroke (Group 1 = 4.4% vs group 2 = 3.2%, P = 0.725) or mortality (Group 1 = 5.9% vs Group 2 = 1.6%, P = 0.206). Rates of pump thrombosis however were lower in Group 1 (Group 1 = 0% vs Group 2 = 6.5%, P = 0.033). Our study showed a high prevalence of triple-therapy antithrombotic use in LVAD patients with no significant differences in bleeding, stroke or survival. However, the risk for pump thrombosis was lower at 1-year when compared to patient receiving MAPT.

Utility of Routine Serum LDH After HeartMate 3 Left Ventricular Assist Device Implantation

<h3>Purpose</h3> This study aims to evaluate the fluctuation of serum Lactate Dehydrogenase (LDH) in patients who are post-HeartMate 3 (HM3) Left Ventricular Assist Device (LVAD) implantation and to determine if routine monitoring of serum LDH values has changed management of patients, outcomes, or detected any pump thrombosis events. <h3>Methods</h3> This is a retrospective cohort study reviewing the electronic medical records of forty-eight HM3 LVAD patients at a tertiary care center in New Jersey, USA with implant dates ranging from 2017 to 2021. For each of these patients, serum LDH values were obtained including baseline values pre-implantation as well as fixed points in time post-operatively, specifically one week, one month, three months, six months, one year, one and a half years, and two years post-implantation as applicable for each patient. Each abnormal LDH value underwent further chart analysis to see if there was any change in clinical status, outcomes, management, or pump thrombosis event. An abnormal serum LDH value was defined as greater than 2.5 times the upper limit of normal, which has been standard practice to evaluate for pump thrombosis and/or hemolysis. <h3>Results</h3> Chart review of forty-eight HM3 LVAD patients showed that routine monitoring of serum LDH values did not change clinical outcomes or management of patients. Forty-six out of forty-eight patients did not have any recorded serum LDH value greater than 2.5 times the upper limit of normal post-implantation. The two patients with elevated serum LDH values post-operatively were never stable enough to be discharged from the hospital and expired shortly after implantation. There was also a 0% rate of pump thrombosis. <h3>Conclusion</h3> Routine monitoring of serum LDH in patients who are post-HM3 LVAD implantation does not change management or outcomes in asymptomatic patients. Therefore, ending routine monitoring of serum LDH eliminates unnecessary blood draws for patients and could represent a savings in healthcare costs as well as resources.

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.

Comparing HVAD Inflow Cannula Angle between Median Sternotomy and Thoracotomy

<h3>Purpose</h3> Left ventricular assist device (VAD) implantation via thoracotomy is a safe operation with potential advantages compared to conventional sternotomy. One proposed advantage is improved inflow cannula (IFC) positioning due to better visualisation. We investigated the difference in IFC angles for patients with HVADs implanted via these techniques and compared post-operative as well as long term outcomes. <h3>Methods</h3> 42 patients were retrospectively selected from our VAD database. 28 in the sternotomy group and 14 in the thoracotomy group. We included all thoracotomy implants performed at our centre and consecutive sternotomy implants from 2015-2019. Inclusion required a minimum support time of 30 days. Patients with concomitant procedures were excluded. The first post-operative CT chest scan was used to measure the angle between the IFC and mitral valve in axial and coronal planes. <h3>Results</h3> There was no significant difference in gender, INTERMACS score, BMI or age between the two groups. Median support time was not significantly different between the thoracotomy and sternotomy groups (328 vs 360 days, p=0.9). Median cardiopulmonary bypass (CPB) time was higher in the thoracotomy group (104 vs 78 minutes, p<0.01). Median ICU length of stay for the thoracotomy group was 5 days compared to 8 days in the sternotomy group, p=0.08. There was no significant difference in median IFC angle on the axial plane between the thoracotomy group and the sternotomy group (9 degrees v 10 degrees, p=0.3). Similarly, there was no difference in the coronal plane (9 degrees vs 12 degrees, p=0.9). Rates of pump thrombosis, stroke and GI bleeding were not significantly different between the two groups. <h3>Conclusion</h3> In our sample size of 42 patients, the thoracotomy group had a slightly longer CPB time, however, there was no difference in IFC angle, pump thrombosis, GI bleeding, stroke or ICU length of stay. In saying this, there may be other benefits to the thoracotomy approach such as facilitating easier sternal entry upon transplantation.

Impact of Gastrointestinal Bleeding Following LVAD Implant in a Destination Therapy Population

<h3>Purpose</h3> To determine the association of gastrointestinal bleeding (GIB) over 5 years on morbidity and mortality in patients receiving the HeartWare^TM HVAD^TM System for destination therapy. <h3>Methods</h3> HVAD patients enrolled in the ENDURANCE and ENDURANCE Supplemental trials were eligible. Patients were separated into two groups: those who experienced a GIB and those who did not. Baseline characteristics, adverse events and survival through 5 years were examined. <h3>Results</h3> Of the 604 eligible patients, 284 (47.0%) suffered at least one GIB through 5 years post implant. The median time to first GIB was 260.5 days. Patients with GIB were older (65.2 vs 62.2, p=0.001), more likely to have a history of smoking (72.5% vs. 64.1%, p-0.03), and had greater incidence of atrial fibrillation (59.2% vs. 46.3%; p=0.002). (Fig 1A) Patients with GIB had lower rates of pump thrombosis (0.07 vs. 0.13; p<0.0001), thromboembolism (0.03 vs. 0.05; p=0.02), ICVA (0.10 vs. 0.14, p=0.02), HCVA (0.06 vs. 0.10, p=0.01), driveline infection (0.16 vs. 0.23; p=0.006), and arrhythmia (0.26 vs. 0.37; p=0.01) compared to the non-GIB cohort. (Fig 1B). Time in therapeutic range (TTR) prior to first GI bleed did not differ from TTR over 2 years for patients who did not have GI bleed (64.5% vs. 64.0%, p=0.92). Three-month mortality following GIB was 13.6%. Five-year KM survival for all patients with GIB was 28.3% while 5-yr survival for patients without a GIB was 27.3%. Of the 284 patients who had GI bleed, 155 (54.6%) had >1 GIB. Patients with >1 GIB were older (66.3 vs 63.9, p=0.04), and were more likely to have a history of smoking (79.4% vs 64.3%, p=0.005) and diabetes (55.5% vs. 42.6%, p=0.03) (Fig 1C), and were more likely to have other bleeding-related events. (Fig 1D) <h3>Conclusion</h3> HVAD patients experiencing a GIB event had significantly lower rates of stroke and pump thrombosis. The reason for this observation is uncertain and deserves further exploration. Patients with recurrent GIB were older, more commonly diabetic, and more likely to have serious bleeding events.

HVAD Lavare Cycle Reduces Cerebrovascular Events and Improves Survival

<h3>Purpose</h3> The Lavare Cycle (LC) is a pre-programmed speed modulation algorithm in the HVAD device designed to automatically increase both ventricular and pump washing<b>.</b> The ReVOLVE trial suggested a reduction in adverse outcomes including stroke. We assessed the effect LC ON compared to LC OFF on HVAD implants. <h3>Methods</h3> We conducted a retrospective, single center study from 4/2017 to 6/2020 including all 46 patients who received a HVAD implant. The LC became available to our center on 06/2018. For the majority of patients LC was turned on at the time of implant admission. The primary endpoints were cerebrovascular events (CVE) by INTERMACS definition and survival between LC ON versus LC OFF. Secondary endpoints were GI bleeding and pump thrombosis rates. <h3>Results</h3> Fourty six patients (median age 57 years, 78% male, 58% non-ischemic cardiomyopathy) were implanted with HVAD device from 4/2017 to 6/2020. The median duration of HVAD support was 648 (245-902) days. The LC was activated in 33/46 patients. Median time to cycle activation in the LC ON group from implantation was, median (IQR): 4 (1-36) days. The LC ON group experienced less incidence of CVEs, with 6/33 (18%) in the ON vs. OFF 6/13 (46%), p=0.04 (Fig 1A). The median time of CVE from implant was for LC ON and OFF 223 and 104 days, respectively. Survival was significantly improved in the LC ON 31/33 (94%) vs OFF 7/13 (54%), p=0.003 (Fig 1B). There were however 7/33 GI bleeding events in the ON group while zero events in the OFF, p=0.08. Pump thrombosis events were equal rate in the ON 3/33 (9%) vs OFF 1/13 (8%), p=0.43. <h3>Conclusion</h3> LC ON was associated with a significant lower number of CVE (p =0.04) and better survival (p=0.003). The important impact of speed modulation on reducing neurologic events should be confirmed in a larger HVAD patient population.

A Hemolytic Event in a Heartmate 3 Patient in the Setting of Polycythemia

Introduction The Heartmate 3 (HM3) LVAD has significantly reduced hemocompatibility events. We present a case of a hemolytic event in a HM3 patient likely related to underling polycythemia. Case Report A 49-year-old man with multisystem sarcoidosis (pulmonary and cardiac) complicated by stage D systolic heart failure status post HeartMate 3 left ventricular assist device (LVAD) implantation and secondary polycythemia attributed to chronic hypoxic respiratory disease and pulmonary hypertension presented with symptoms of left arm numbness and tingling followed by severe substernal chest pain. Initial examination was unremarkable. EKG revealed nonspecific intraventricular conduction delay. Troponin I was elevated at 6.1. Hemoglobin was elevated to 19. LDH was elevated to LDH 568 from baseline of 300s. INR was 1.6 upon arrival. LVAD interrogation revealed speed 5600 rpm, flow 4.5 L/min, power 4.4 Watts and pulsatility index of 4.8. Heparin drip, aspirin and statin were initiated for presumed NSTEMI. LDH remained elevated to 600s. Left heart catherization revealed an acute clot in mid-circumflex associated with 50% stenosis consistent with partial resolution of thrombosis. Further workup revealed normal haptoglobin, erythropoietin and total bilirubin levels however plasma free hemoglobin was elevated to 63.1. Urine hemoglobin was not detected. A JAK2 mutation was excluded. Slow therapeutic phlebotomies with replacement of 125cc of blood with equivalent normal saline were initiated given concern for hemolytic event in the setting of worsening polycythemia. Renal imaging was negative and pretest probability for hematologic malignancies remained low. Of note, the patient reported non-compliance with home oxygen therapy used only at the time of exertion. Compliance was reinforced. Subsequently, LDH trended down to baseline following successful heparin bridge to therapeutic warfarin level. The patient was discharged in stable condition. Summary An acute hemolytic event (and possible cardioembolic NSTEMI) was seen in our patient evidenced by an elevation of LDH, plasma hemoglobin and new coronary thrombus in the setting of worsening polycythemia. Despite a remarkable low rate of pump thrombosis, HM3 recipients with acquired pro-thrombotic states such as polycythemia maybe at risk for adverse hemocompatibility events. Close surveillance is warranted for these special populations.

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.

The Root of All Thrombi: Coronary Artery Thromboembolism Post Heartmate3

<h3>Introduction</h3> Aortic root thrombosis (ART) is a rare complication of left ventricular assist device (LVAD) therapy and can cause thromboembolic events. We present a case of ART complicated by coronary artery occlusion, myocardial infarction and recurrent ventricular tachycardia (VT) 2 months after HM3 implantation. <h3>Case Report</h3> 62 year old female with non-ischemic cardiomyopathy and HM3 presented 2 months post-implant with chest pain, low flow alarms, and ICD shock. Exam showed MAP 55 mm hg, pump flow 3.4 LPM, speed 5200 RPM, pulsatility index 5.2. LVAD interrogation showed multiple PI events. Her left ventricle was 5.2 cm with closed aortic valve and midline septum. TAPSE was 1.1cm. ECG showed new RBBB. Troponin T peaked at 9035 ng/dL. LDH peaked at 1361 U/L. BNP was 2194 pg/mL. INR range was 2.4-2.7 the month prior. VT initially resolved after decreasing VAD speed to 4800 suggesting suction as a trigger. She received fluids, antiarrhythmics and developed right ventricular dysfunction requiring inotrope support. Persistent chest pain and recurrent VT led to coronary angiography, which showed occlusive thrombus from aortic root to left main and left anterior descending arteries. Using embolic protection devices, clot was mechanically aspirated (Fig 1). Eleven days later, she developed an acute left posterior cerebral and basilar artery stroke. Attempted clot aspiration was complicated by intracranial hemorrhage. <h3>Summary</h3> Hemocompatibility related adverse events remain an issue with the HM 3. Lower rates of pump thrombosis were reported in the MOMENTUM trials, but thrombi can form at other sites such as outflow graft and aortic root, causing embolic complications. Closed aortic valves form a blind pouch, increasing the risk of ART especially if INR is subtherapeutic. Early imaging of the aortic root and coronary arteries should be considered for unexplained VT irrespective of coronary anatomy and risks and benefits of intervention using embolic protection devices can be considered after careful multidisciplinary evaluation.

Flow Pulsatility and Outcomes in Continuous-Flow Ventricular Assist Devices

Purpose Flow pulsatility, or the fluctuation between low and high flows seen in native circulation, is an important factor in maintenance of normal endothelial and vascular biology. Conversely, the loss of flow pulsatility seen in continuous flow ventricular assist devices (VAD) has been implicated in the development of gastrointestinal (GI) angiodysplasia. We seek to better understand the impact of flow pulsatility on clinical outcomes. Methods We conducted a single-center retrospective cohort study examining hemodynamic and outcomes in HeartWare (HVAD)-supported patients from 2014-2020. Logfile data was interrogated for current, voltage, and pump flow. Flow pulsatility indices (PI) were derived using Granegger's validated pump flow estimation formula (Granegger M, et al. Artificial Organs. 2012). A proprietary algorithm was applied to standardize values between different generations of pump controllers. Results We calculated PI values for 90 patients, 16% of whom were female. Patients who experienced pump thrombosis had significantly higher PI compared to those who did not (1.37 vs. 0.98, p=0.033). Additionally, there were numerically fewer intracerebral hemorrhage (ICH) events in patients with low PI (tertile 1.1) (0 versus 5 and 3 respectively, p=0.052). Other complications including GI or other major bleeding, ischemic stroke, renal dysfunction, and driveline or other major infections did not differ between tertiles. Conclusion Patients with high PI experienced a higher rate of pump thrombosis compared to those with lower PI. This may be due to increased residence time of blood within the pump causing blood stasis and thrombus formation. Larger cohort studies are needed to corroborate these observations and identify other predictors of these important complications of VAD therapy.

Outcomes over One and a Half Decade Following HeartMate II versus HeartMate 3 Left Ventricular Assist Device Therapy: The Rotterdam Experience

<h3>Purpose</h3> Continuous-flow left ventricular assist device (LVAD) therapy has become an indispensable treatment modality for patient with end-stage heart failure. Therefore, our aim is to evaluate our results with 2 contemporary generations of the mainstream LVAD device types, being the HeartMate II (HMII) and HeartMate 3 (HM3), with over one and a half decade of experience, in the treatment of end-stage heart failure patients within our tertiary referral center. <h3>Methods</h3> We included all adult patients implanted with an LVAD from December 2006 until December 2019. The primary outcome was early and late survival. Secondary outcomes included multiple adverse events, both early and late. <h3>Results</h3> In total, 133 patients (mean age 56 ± 12 year, 77% male) underwent implantation of an LVAD: 64 (48%) received an HMII and 69 (52%) received an HM3, with a median follow-up period of 768 days [IQR 221-1206] and 427 days [IQR 269 - 962], respectively. The HM3 patients were compared to the HM II group older (57 ±10 vs 49±12), had a higher median body mass index (25.6 [IQR 22.5-28.1] vs 22.8 [IQR 20.7-25.1]) and less frequently implanted as bridge-to-transplant (26 (30%) vs 61 (70%)). However, despite the increased age and rate of morbidity, survival (both early and late) were similar for both patient groups, as displayed in the <b>Figure</b>. Furthermore, bleeding events, rates of stroke, re-thoracotomy rates, and confirmed pump-thrombosis rates did not differ between both groups. <h3>Conclusion</h3> Despite the older age and relatively higher risk profile of the second era HM 3 patients compared with the HM II patients, the rate of adverse events did not differ between both groups. Similarly, the survival remains favorable regardless of a lower transplantation rate and higher destination therapy strategy in the HM3 group. Therefore, LVAD therapy remains an excellent modality to improve both the quality of life and survival in a broad range of end-stage heart failure patients.

Rate of Thromboembolic and Bleeding Events in Patients Undergoing Concomitant Aortic Valve Surgery with Left Ventricular Assist Device Implantation

Background: Significant aortic regurgitation at the time of left ventricular assist device (LVAD) implantation, requires concomitant aortic valve (AoV) replacement or repair. However, the impact of concomitant AoV surgery on morbidity remains unknown. Therefore, our aim is to determine the impact of concomitant AoV surgery on thromboembolic and bleeding events. Methods: A retrospective IMACS registry study, including patients implanted from 2013 until September 2017. Differences between different concomitant AoV surgery modalities were analyzed. Results: In total, 785 (5.1%) out of 15.267 patients (median age 58 IQR 49-66 years, 79% male) underwent concomitant AoV surgery (median age 63 IQR 54-69 years, 84% male); 386 (49%) patients received biological prostheses, 71 (9%) mechanical prostheses and 328 (42%) AoV repairs. In total, 54 (8%) patients with AoV surgery experienced a thromboembolic event and 1016 (9%) patients with no AoV surgery. Only AoV repair surgery was associated with an increased rate of pump thrombosis (p=0.024). Furthermore, concomitant AoV surgery was associated with an increased rate of all and nonsurgical bleedings. Following a multivariable Cox regression, concomitant AoV surgery remained an independent predictor for bleeding events. Conclusions: In LVAD patients undergoing concomitant AoV surgery, thromboembolic event rates were not higher, however both all and nonsurgical bleeding event rates were higher. Furthermore, concomitant AoV repair surgery was associated with an increased rate of pump thrombosis.

Early Post-operative Pump Thrombosis In Heartmate 3 LVAD Recipients: A Case Series

Background The HeartMate 3 (HM3) left ventricular assist device (LVAD) has a low reported rate of pump thrombosis. In this case series, we report two HM3 LVAD recipients who developed acute pump thrombosis in the early post-operative period. Case 1 A 69 M with ischemic cardiomyopathy who underwent HM 3 implant as destination therapy (DT). Apical calcium was noted intra-operatively and was removed at the time of surgery. On post-operative day 3, the patient developed low flows alarms, high powers, and increased arterial line pulsatility. Lactate dehydrogenase (LDH) was within normal limits and heparin was therapeutic. Pump interrogation demonstrated rising pump temperature (70°C) with intermittent pump stops. The decision was made to return to the operating room (OR) and during this time the patient developed hypotension and lactic acidosis. In the OR fresh thrombus of the inflow, pump and outflow graft was encountered. The pump was exchanged to a new HM3 and the patient had full recovery with no further thrombotic events. Case 2 A 58-year-old woman with Adriamycin associated cardiomyopathy underwent DT HM3 implantation with tricuspid valve annuloplasty. The LV cavity size decreased from 5.9 cm pre- operatively to 4.0 cm post-operatively, causing septal contact with the inflow cannula and intermittent ventricular tachycardia. On post-operative day 3 the patient developed low flow alarms, followed by elevated pump flows and powers and return of arterial line pulsatility. LVAD interrogation demonstrated a high pump temperature (75 °C) with intermittent pump stops. Similar to the first patient, the second patient had a normal LDH, was therapeutic on a heparin drip, and developed hemodynamic instability. The same findings (inflow, outflow, and intra pump thrombus) were present at in the OR. This second patient's pump was re-positioned reduce septal contact at the time of exchange. Discussion Here we report 2 cases of acute HM3 pump thrombosis shortly after LVAD implantation. Full investigation into these events internally and with the manufacturer did not reveal pump malfunction. The first event was felt to be caused by ingestion of calcified material from the left ventricle leading to rotor misplacement and subsequent thrombus formation. The second case was thought to be triggered by sustained low flow from the septal contact with subsequent thrombus formation. In each case, the patients developed high powers, return arterial line pulsatility, and dangerously high internal pump temperatures. The purpose of this case series is to help the community develop pattern recognition in order to be able to quickly diagnose this rare but serious event.

Outcomes of left ventricular assist device implantation in hypercoagulable patients.

The aim of this study was to evaluate outcomes of left ventricular assist devices (LVADs) in patients who tested positive for hypercoagulable hematologic disorders. Adults undergoing continuous-flow LVAD implantation with preoperative hypercoagulability testing between 2004 and 2018 at a single center were reviewed. Hypercoagulability was defined as testing positive for antiphospholipid antibody, anticardiolipin antibody, lupus anticoagulant, protein C, protein S, factor V Leiden, and/or heparin-induced thrombocytopenia. The primary outcome was survival on the original LVAD. Secondary outcomes included rates of thromboembolic complications and readmission for intravenous heparin treatment. A total of 270 LVAD patients with pre-implant hypercoagulability testing were included, and 157 (58%) tested positive for a hypercoagulable disorder. Of those testing positive, 10 (6.4%) had a clinical pre-LVAD history of thromboembolic events. Survival was comparable between hypercoagulable and non-hypercoagulable patients (1 year: 73.3% vs 78.9%, P = .2195, 2-year: 60.7% vs 62.8%, P = .3627). Rates of pump thrombosis (14.0% vs 13.3%, P = .8618), hemolysis (4.5% vs 3.5%, P = .3536), stroke (18.5% vs 14.2%, P = .3483) and readmission for IV heparin therapy (87.3% (n = 137) vs 77.9% (n = 88), P = .7560) were similar. Outcomes were comparable in patients with positive hypercoagulable tests when stratified by pre-implant clinical history of hypercoagulability as well as stratified by recent preoperative exposure to heparin or warfarin. In this series, positive laboratory tests for hypercoagulability were common amongst patients undergoing LVAD implantation although few had positive clinical histories. Survival and freedom from thromboembolic complications were comparable to non-hypercoagulable patients. Hypercoagulability alone should therefore not serve as a contraindication to LVAD implantation.

Mechanical Blood-Immersed Bearings in Continuous-Flow Rotary Blood Pumps.

Mechanical blood-immersed bearings have been used in many continuous-flow rotary blood pumps to reduce friction between relatively moving parts, but their use has been associated with a significant incidence of pump thrombosis. As newer cardiac assist devices with more advanced bearings become available, the rate of pump thrombosis will likely decrease. Nevertheless, it is important to understand the design limitations of mechanical bearings as pumps utilizing them are still in use as chronic support devices and especially in the acute setting for temporary support devices. A properly designed journal bearing should support the spinning rotor with no surface-to-surface contact between the bearing and journal surfaces. The journal continuously undergoes orbital motion within the bearing, which can be "stable" or "unstable." Unstable orbital motion causes the journal to move progressively off-center until it collides with the bearing, and even minor variations in manufacturing can create off-design operation and dynamic instability of the journal. Since blood is the lubricant in most clinically-used rotary blood pumps, lubricant viscosity can vary abruptly in response to changes in hematocrit or plasma protein concentration. Additionally, shear stress from the high-speed rotor can cause hemolysis and plasma protein denaturation. We reviewed theoretical design and operating principles of mechanical bearings and discuss why the phenomenon of mechanical bearing thrombosis may be an inherent design issue dependent on variables that are beyond the control of clinicians.

Worldwide Gender Differences during Mechanical Circulatory Support: An Analysis of the International Society for Heart and Lung Transplantation Mechanically Assisted Circulatory Support Registry Data

The aim of this study is to investigate gender differences of patients on mechanical circulatory support (MCS) using data of the International Society for Heart and Lung Transplantation (ISHLT) Mechanically Assisted Circulatory Support (IMACS) registry. We hypothesize that gender differences lead to differences in implantation data, perioperative complication rates as well as in mid- and longterm outcome among patients undergoing MCS therapy and that these outcomes differ between continents. The study was performed using the IMACS registry database of the International Society for Heart and Lung Transplantation.Patients receiving right (temporary or permanent) or left ventricular assist devices and patients with biventricular assist devices were included leading to a total number of 17329 patients. For each computation, only cases without missing values on the variables involved in that particular analysis were analyzed. We included 17329 patients who underwent MCS, either with left ventricular support only or additional right ventricular support. Mean patients age was 54.2 ± 15.4 years and did not differ significantly between the two groups. The majority of the patients was male (78.2%). In both groups most of the devices were implanted to bridge the patients to transplantation (60.5% female vs 57.9% male). There was a significant difference regarding need of temporary right ventricular support (2.6% female vs 2 % male; p=0.048) and women underwent significantly more frequent implantation of biventricular mechanical support (6.6% female vs 4.6% male; p< 0.001). There was no significant difference for the occurrence of bleeding events in general but women showed more intra-abdominal and urinary tract associated bleeding complications (2.8% female vs 2.4% male; p= 0.025). The rate of pump thrombosis was significantly higher in the male patient group with 1.3% vs 0.8% among female patients (p=0.003). Final results including intercontinental comparisons will be presented at the annual meeting of the ISHLT 2020. Results of this study may guide physicians and caregivers in better understanding gender specific differences and may improve overall outcomes.

Increased Rate of Pump Thrombosis and Cardioembolic Events Following Ventricular Tachycardia Ablation in Patients Supported With Left Ventricular Assist Devices.

Ventricular arrhythmias are common following left ventricular assist device implantation (LVAD), and the effects of ventricular tachycardia (VT) ablation on thrombosis and embolic events are unknown. We aimed to assess LVAD thrombosis, stroke, and embolic event rates after VT ablation. Left ventricular assist device implantation patients from two academic centers who underwent endocardial VT ablation between 2009 and 2016 were compared to a control group with VT who were not ablated and followed for one year. The primary composite outcome was confirmed or suspected LVAD thrombosis, stroke, or other embolic event. Survival analysis was conducted with Kaplan-Meier curves, log-rank tests, and Cox regression. Forty-three LVAD patients underwent VT ablation, and 73 LVAD patients had VT but were not ablated. Patients who were ablated were more likely have VT prior to LVAD (p = 0.04), monomorphic VT (p < 0.01), and to be on antiarrhythmics (p < 0.01). Fifty-eight percent of the patients in the ablation group experienced the primary composite outcome (11% had confirmed device thrombosis [DT], 41% suspected DT, 39% had a stroke or embolic event) compared to 30% in the control group (12% with confirmed DT, 11% with suspected DT, 14% with stroke or embolic event) (p = 0.002). In multivariable regression, ablation was an independent predictor of the primary composite outcome (hazard ratios, 2.24; 95% confidence interval, 1.09-4.61; p = 0.03). Patients with LVADs referred for endocardial VT ablation had elevated rates of DT and embolic events.

ACUTE PUMP THROMBOSIS IN A HEARTMATE III

The newest centrifugal-flow (CF) left ventricular assist device (LVAD), the HeartMate 3 (HM3), has significantly lower rates of pump thrombosis. There is lack of literature regarding HM3 thrombosis in situ. A 55 year old man with an ischemic cardiomyopathy (LVEF 15%) and chronic idiopathic