LVAD Thrombosis Research Articles

(1193) - Percutaneous Left Atrial Appendage Occlusion Devices and Continuous Flow LVAD Thrombosis: An Occult Source of VAD Thrombosis?

(1193) - Percutaneous Left Atrial Appendage Occlusion Devices and Continuous Flow LVAD Thrombosis: An Occult Source of VAD Thrombosis?

Risk of Infections With Long-Term Left Ventricular Assist Device Support.

We retrospectively reviewed all the patients who underwent new continuous-flow (C-F) LVAD implantation between January 1, 2013, and December 31, 2014, at the University of Nebraska Medical Center. Patients were followed until heart transplant, LVAD explantation, death, or December 31, 2017. We defined LVAD infections as per the International Society of Heart and Lung Transplantation (ISHLT) definition: VAD-specific, VAD-related, and non-VAD infections. The primary outcome was to calculate the incidence of LVAD infections per 1000 days of LVAD support. Secondary outcomes were to assess the cause of death and the effect of bloodstream infections on LVAD thrombosis, stroke, and death. During the study period, a total of 94 patients underwent a C-F LVAD implantation. Five patients were lost in follow-up; 89 patients were included in the study. The mean age at LVAD implantation was 54 (SD+15) years. Out of 89 patients, 67 (75%) were men, and 53/89 (71%) received LVAD as destination therapy (DT). At the time of LVAD implantation,34/89 (38%) patients had ITERMACS (interagency registry for mechanically assisted circulatory support)score 1 (cardiogenic shock). The median duration of LVAD support was 387+493 days, with an interquartile range of 140 to 1083 days. The incidence rate of infections post-LVAD implantation decreased from 3.2 /1000 LVAD days (95% confidence interval [CI] 2.54-4.03) during the first year of LVAD support to 0.78/1000 LVAD days (95% CI, 0.38-1.65) during the following third year of LVAD support. Similarly, the incidence of VAD-specific infections in the first year post-LVAD implantation versus the third-year post LVAD implantation decreased from 0.83/1000 LVAD days (95% CI, 0.53-1.30) to 0.33/1000 LVAD days (95% CI, 0.10-1.04). On univariate survival analysis, an increased risk of death was associated with a one-year increase in age at LVAD implantation (hazard ratio (HR) 1.05 (95% CI, 1.01-1.09), p=0.01), the presence of infection within 30 days before LVAD implantation (HR 2.44 (95% CI, 1.09-5.48), p=0.03), underlying ischemic cardiomyopathy (HR 2.96 (95% CI, 1.28-6.80), p=0.01), and lower ITERMACS profile HR 3.64 (95% CI, 1.09-12.13, p=0.04). Bloodstream infections (BSIs) were not associated with an increased risk of death (HR 1.63 (95% CI, 0.56-4.80, p=0.37). Univariate survival analysis for poor outcomes (LVAD thrombosis, stroke, or death) showed BSIs increased the risk of having a poor outcome (HR 2.39 (95% CI, 1.02-5.57), p=0.04). The incidence rate of post-LVAD infections decreased significantly over time. LVAD implantation may not be contributing to immune suppression as previously suggested. In our study, BSIs were found to have a significantly increased hazard ratio for a poor outcome post-LVAD implantation.

Assessing in-hospital cardiovascular, thrombotic and bleeding outcomes in patients with chronic liver disease undergoing left ventricular assist device implantation

IntroductionChronic liver disease (CLD) and advanced heart failure (HF) often co-exist with coagulopathy and hematologic abnormalities being major concerns in this cohort. Perioperative outcomes of patients undergoing LVAD implantation can be affected by coagulopathy, associated with a higher International Normalized Ratio (INR) and cytopenias, as well as pre-operative use of antiplatelet therapy and systemic anticoagulation. Our study is aimed at evaluating the in-hospital mortality and clinical outcomes of patients with CLD who underwent LVAD implantation compared to patients who underwent LVAD implantation without CLD. MethodsThe National Inpatient Sample Database was queried from 2012 to 2017 for relevant International Classification of Diseases (ICD)-9 and ICD-10 procedural and diagnostic codes.Baseline characteristics and in-hospital outcomes were compared in patients with chronic liver disease and those without, who underwent LVAD implantation. ResultsA total of 22,955 patients underwent LVAD implantation, 2200 of which had CLD. There was no difference in mean age between those with and without CLD (52.8 ± 14.2 vs. 55.7 ± 15.4 years old, p < 0.001), and 23.7% of patients were female. The proportion of patients with CLD undergoing LVAD implantation trended downward between 2012 and 2017 (average annual growth rate: “−14.8%”). In-hospital post-LVAD outcomes revealed: all-cause inpatient mortality (14.8% vs. 11.1%), major bleeding (34.3% vs. 30.2%), transfusion of platelets (18.0% vs. 14.0%), subarachnoid hemorrhage (1.6% vs. 0.7%) and hospital length of stay were greater in patients with CLD (p < 0.001 for all values). LVAD thrombosis (6.6% vs. 9.4%) and postoperative ischemic stroke (3.4% vs. 6.1%) occurred less in patients with CLD (p < 0.001 for both). There were no statistically significant differences in occurrence of post-LVAD gastrointestinal bleeding and transfusion of fresh frozen plasma or packed red blood cells (p > 0.05 for all). Using a multivariate logistic regression model to adjust for confounding factors, CLD was predictive of increased in-hospital all-cause mortality in patients undergoing LVAD implantation (adjusted odds ratio: 1.29, 95% confidence interval [CI]; 1.06 to 1.56, p = 0.010). ConclusionLVAD implantation in patients with chronic liver disease was associated with increased mortality and post-LVAD major bleeding with increased utilization of platelet products yet comparable thrombotic complications. Further studies are needed to evaluate the balance and pathophysiology of bleeding risks when compared to thrombosis, as well as predictors in patients with chronic liver disease.

Management of Ischemic Stroke Following Left Ventricular Assist Device

BackgroundAcute ischemic stroke is a common complication and an important source of morbidity and mortality in patients with left ventricular assist devices. There are no standardized protocols to guide management of ischemic stroke among patients with left ventricular assist device. We evaluated our experience treating patients who had an acute ischemic stroke following left ventricular assist device placement. MethodsWe retrospectively reviewed all patients who underwent left ventricular assist device placement from 2010–2019 and identified patients who had acute ischemic stroke following left ventricular assist device placement. ResultsOf 216 patients having left ventricular assist device placement (mean±SD age 52.9±16.2 years, women 26.9%), 19 (8.8%) had acute ischemic stroke (mean±SD age 55.8±12.0 years, women 36.8%). Median (interquartile range) time to ischemic stroke following left ventricular assist device placement was 96 (29-461) days. At the time of the ischemic stroke, 16/19 (84.2%) patients were taking both antiplatelet and anticoagulation therapy, 1/19 (5.3%) patient was receiving only anticoagulants, 1/19 (5.3%) patient was taking aspirin and dipyridamole, and 1/19 (5.3%) patient was not taking antithrombic agents. INR was subtherapeutic (INR<2.0) in 7/17 (41.2%) patients. No patient was eligible to receive thrombolytic therapy, while 5/19 (26.3%) underwent mechanical thrombectomy. Anticoagulation was continued in the acute stroke phase in 11/19 (57.9%) patients and temporarily held in 8/19 (42.1%) patients. Hemorrhagic transformation of the ischemic stroke occurred in 6/19 (31.6%) patients. Anticoagulation therapy was continued following ischemic stroke in 4/6 (66.7%) patients with hemorrhagic transformation. ConclusionsWhile thrombolytic therapy is frequently contraindicated in the management of acute ischemic stroke following left ventricular assist device, mechanical thrombectomy remains a valid option in eligible patients. Anticoagulation is often continued through the acute phase of ischemic stroke secondary to concerns for LVAD thrombosis. The risks and benefits of continuing anticoagulation must be weighed carefully, especially in patients with large infarct volume, as hemorrhagic transformation remains a common complication.

Hybrid Thrombolysis for Left Ventricular Assist Device Thrombosis

LVAD thrombolysis can be effective but carries a bleeding risk. Existing data suggest intraventricular (vs peripheral) delivery may reduce bleeding, but is associated with early recurrence. We have developed a novel hybrid thrombolytic approach (hTL) using an initial high dose LV delivery of alteplase followed by a maintenance LV infusion. We studied all patients with durable LVAD pump thrombosis (PT) treated with hTL in our institution between 1/2015 and 9/2019. We report the technique, procedural success and complications. We identified 10 patients with median (IQR) age 56 years (50, 64 years). All had undergone Heartware HVAD implantation. Duration of LVAD support preceding PT was 518 days (172, 920 days). All patients had significant increases in power and haemolysis markers, and were treated initially with heparin and tirofiban (n=9) or heparin alone (n=1). Time to hTL was 3 days (2, 5 days). hTL was done in the cardiac catheterisation laboratory after informed consent. Heparin and tirofiban were stopped in advance. An arterial sheath was placed in a femoral (n=5) or radial (n=5) artery. A pigtail catheter was advanced to the LV under fluoroscopic guidance. Alteplase was infused at 1mg/min and stopped when LVAD power returned to baseline. The pigtail catheter was left in situ, and the alteplase maintenance infusion continued at 1mg/hour to a weight-adjusted maximum. The sheath and catheter were then removed. Median total alteplase dose was 74mg (48, 90mg). There was acute normalisation of pump power in 8 patients, and 6 remained free of thrombosis at 1 year. Among these 6, 3 were bridged to transplant and 3 continue on LVAD support. In the 2 patients with recurrent thrombus (at days 8 and 37), 1 was managed with inotropes and urgent transplant, and 1 died. In the 2 acute non-responders, 1 went for urgent pump exchange and 1 died. There was no procedure-related bleeding or death. Two patients had vascular access site haematoma (both femoral access), and a further 3 patients had minor bleeding not requiring intervention. Three patients developed acute kidney injury probably related to haemolysis. We report a hTL protocol for LVAD thrombosis with 80% initial success, low rate of recurrent thrombosis, and no major bleeding. Interpretation is limited by small group size and retrospective design. These outcomes require comparison with other approaches, ultimately in a randomised trial.

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.

Comparison of Unfractionated Heparin and Bivalirudin for Treatment of Suspected Device Thrombosis during Heart Mate II Support

Purpose Although intravenous anticoagulation is the mainstay medical therapy employed during CF LVAD thrombosis, the comparative impact of indirect thrombin inhibition with unfractionated heparin (UH) and direct thrombin inhibition with bivalirudin (BV) is unknown. Methods We conducted a single center review of all patients with a Heart Mate(HM) II who were admitted for suspected device thrombosis (SDT) from September 2011 to September 2018. Device thrombosis was suspected due to elevated outpatient lactate dehydrogenase (LDH), evidence of systemic emboli, or device alarms. After admission, patients were categorized into those receiving UH or BV. Crossovers were excluded. Freedom from device exchange was calculated with Kaplan Meier analysis. Results Twenty-three patients were admitted for SDT, of whom 13 received UH and 10 received BV. There were no differences in age (UH: 49.2 vs. BV: 46.9 years, p=0.60) and time from implant to SDT (UH: 10.3 vs. BV: 10.4 months, p=0.98). LDH remained elevated after UH (879, IQR: 755-1049 to 1028, IQR: 550-1438 U/L, p=0.34) but dropped with BV (839, IQR: 733-914 to 453, IQR: 352-465 U/L, p=0.002). During the follow up period, there was a lower likelihood of a device exchange in patients treated with BV (HR: 0.28, 95% CI: 0.09-0.89, p=0.04, figure 1). Conclusion In this sample of HM II patients, intravenous direct thrombin inhibition was more effective in treating device thrombosis.

Premature Myocardial Infarction as the Presenting Sign of Hypercoagulable Syndrome

Introduction Premature myocardial infarction (MI) in a young patient proves to be a challenge to manage. In the absence of family history or provoking factors, etiology can be difficult to determine. Hypercoagulable syndromes should be considered as an etiology for premature MI, as future management may be influenced by the presence of these syndromes. We report the case of a young heart-kidney transplant recipient presenting with multiple thrombotic events including premature MI, LVAD thrombosis, and deep vein thrombosis (DVT) in the setting of May-Thurner Syndrome (MTS) exemplifying the importance of thorough hypercoagulability testing. Case Report Our patient is a 41-year-old male with a history of MI at age 37, resulting in ischemic cardiomyopathy complicated by cardiogenic shock requiring LVAD placement for bridge to transplant. Patient's post LVAD course was complicated by recurrent LVAD thrombosis despite adequate anticoagulation (AC) requiring two device exchanges. Hypercoagulability testing was limited due to the necessity of chronic AC. One month after undergoing heart-kidney transplant, patient presented with left lower extremity (LLE) pain and difficulty ambulating with duplex ultrasound showing DVT of LLE extending from the L common iliac vein to the L popliteal vein, requiring thrombectomy. Venography identified narrowing of the L common iliac vein confirming the diagnosis of MTS and an iliac vein stent was placed. Repeat hypercoagulability testing revealed an elevated factor VIII (FVIII) activity level to 319% of normal, warranting long-term AC with an elevated therapeutic INR range and high dose aspirin. Patient has had no recurrent thrombosis since starting this regimen. Summary Patients with multiple thrombotic events should undergo thorough hypercoagulability testing to identify risk for future thromboses and need for AC. Traditionally, elevated FVIII levels are thought to be an acute phase reactant, not necessitating AC. However, it has recently been shown that patients with an elevated FVIII level are at significant risk for thrombosis and require long-term AC. Our case highlights the importance of early FVIII level testing in hypercoagulability evaluation.

Advanced telemonitoring of Left Ventricular Assist Device patients for the early detection of thrombosis

In modern times, advanced heart failure is a serious issue. Due to a shortage of donor hearts, the implantation of “Left Ventricular Assist Device” (LVAD) as destination therapy has become a common alternative. The LVAD is a mechanical continuous flow pump. However, there are several LVAD complications e.g. a pump thrombosis as a formation of a blood clot inside the LVAD pump. It can result in pump stoppage and lead to death. In order to ensure the success of thrombolytic therapy, it is important to detect a thrombosis early. Since an increase in LVAD power consumption is one indication for a pump thrombosis, this paper shows three algorithms analyzing the LVAD power. These algorithms test absolute and relative threshold and also consider the circadian fluctuation in LVAD power during the day. For the evaluation, a set of 352 LVAD log files including 7 thromboses was used. Compared to the “High Power Alarm”, which is a predefined thrombosis alarm of the LVAD controller, these algorithms detect all tested LVAD thrombosis up to 140 h earlier. Nevertheless, the algorithms still cause false alarms (<5%) in patients without an LVAD thrombosis.To reach an earlier and more precise LVAD thrombosis detection, continuous LVAD monitoring is required. Because the LVAD does not provide an interface, an Electrocardiography (ECG) based approach is tested as an alternative monitoring to acquire LVAD data. The LVAD produces an electromagnetical field, whose signal is visible in the ECG. It is utilized to calculate the LVAD speed of 9 LVAD patients using the Fast Fourier Transform. An accuracy of 99.8% was achieved. As external events also influence the LVAD measurements, changes in body posture on the LVAD is tested. The results show that the amplitude, measured during supine position, is significantly different to the amplitude measured during sitting and standing.

Feasibility, Efficacy and Safety of Fibrinogen Guided Very Low Dose Multi-Day Thrombolytics in the Management of LVAD Thrombosis

Feasibility, Efficacy and Safety of Fibrinogen Guided Very Low Dose Multi-Day Thrombolytics in the Management of LVAD Thrombosis

Durability of Medical Therapy for Heartware LVAD Thrombosis

Ventricular assist device (VAD) thrombosis in continuous flow (CF) VADs remains a complication that leads to morbidity and mortality. Although treatment of VAD thrombosis in the heartmate II device has favored early pump exchange, Heartware VAD (HVAD) thrombosis may be treated with thrombolytic (lytic) therapy, especially if power consumption does not rise precipitously. The durability of medical therapy with systemic lytics for VAD thrombosis has not yet been described in the literature.

(638) - Early Post-Implant Lactate Dehydrogenase Level and LVAD Thrombosis: A Comparison of Heartmate II and Heartmate III

(638) - Early Post-Implant Lactate Dehydrogenase Level and LVAD Thrombosis: A Comparison of Heartmate II and Heartmate III

(1027) - A Big (Clot) Problem! Extreme Obesity Is Associated with a Higher Incidence of Durable LVAD Thrombosis

(1027) - A Big (Clot) Problem! Extreme Obesity Is Associated with a Higher Incidence of Durable LVAD Thrombosis

(269) - Management and Outcomes of LVAD Thrombosis: A Systematic Review and Meta-Analysis

(269) - Management and Outcomes of LVAD Thrombosis: A Systematic Review and Meta-Analysis

New Challenges in the Treatment of Patients With Left Ventricular Support: LVAD Thrombosis.

Mechanical circulatory support has revolutionized the treatment of heart failure, affording patients significantly improved survival and quality of life. However, further advancements in this technology have been hindered by adverse events, particularly gastrointestinal bleeding, driveline infection, stroke, and device thrombosis. Recently, there has been a renewed focus on device thrombosis as the reported incidence has increased. This review focuses on an update on the diagnostic modalities and current treatment algorithms of this serious complication.

(686) - Elevated Preoperative Plasma Free Hemoglobin and Hemin May Predict LVAD Thrombosis

(686) - Elevated Preoperative Plasma Free Hemoglobin and Hemin May Predict LVAD Thrombosis

Between Scylla and Charybdis: Difficult Balance between Anticoagulation and Bleeding in the Management of LVAD Thrombosis: A Case Report

Case: The patient was a 67 years old male. The patient experienced an episode of LVAD thrombosis. Device replacement was not possible due to high surgical risk. Pharmacological strategy was adopted with intraventricular fibrinolysis+intravenous Tirofiban infusion. Outcome: Despite thrombosis resolution, two episodes of bleeding occurred. Thus we lowered antithrombotic drugs dose with subsequent relapse risk. At the end, a successful therapeutic strategy was achieved. Conclusion: Our case report shows how the balance between anticoagulation and bleeding is a tricky feature of LVAD thrombosis management. When device replacement is not an option, trying to remove the clot soon with aggressive antithrombotic therapy can be a winning strategy and can quickly stop the haemolysis. Unfortunately, it can produce major bleeding events, harmful and potentially life-threatening. To be aware of potential cause of bleeding and looking for the appropriate dosage of antithrombotic drugs can be useful to manage these complications

Increased Risk of LVAD Thrombosis in Patients With a Previous History Thromboembolic Event

Increased Risk of LVAD Thrombosis in Patients With a Previous History Thromboembolic Event

(574) - LVAD Thrombosis Detection Using Third Harmonic Frequency Measured With 3D Accelerometer

(574) - LVAD Thrombosis Detection Using Third Harmonic Frequency Measured With 3D Accelerometer

Diagnosis and Management of LVAD Thrombosis.

Ventricular assist device (VAD) thrombosis is one of the most devastating complications for patients on mechanical assist devices, and has been occurring more frequently during the last 3years for unknown reasons. The diagnosis of VAD thrombosis is challenging and requires knowledge of the various clinical presentations and high vigilance. The current review summarizes various aspects of VAD thrombosis, including possible mechanisms for the formation of VAD thrombus and its clinical presentation, and presents a suggested algorithm in diagnosing this entity, with therapeutic options. High awareness and knowledge of the variable clinical presentations of VAD thrombosis are essential in order to allow early diagnosis, which may decrease the morbidity and mortality associated with this complication.