Survey of Anticoagulation Practices with the Impella Percutaneous Ventricular Assist Device at High-Volume Centers

European practices on antithrombotic management during percutaneous mechanical circulatory support in adults: a survey of the Association for Acute CardioVascular Care of the ESC and the European branch of the Extracorporeal Life Support Organization

AIMS

Bleeding and thrombotic complications compromise outcomes in patients undergoing percutaneous mechanical circulatory support (pMCS) with veno-arterial extracorporeal membrane oxygenation (V-A ECMO) and/or microaxial flow pumps like Impella™. Antithrombotic practices are an important determinant of the coagulopathic risk, but standardization in the antithrombotic management during pMCS is lacking. This survey outlines European practices in antithrombotic management in adults on pMCS, making an initial effort to standardize practices, inform future trials, and enhance outcomes.

METHODS AND RESULTS

This online cross-sectional survey was distributed through digital newsletters and social media platforms by the Association of Acute Cardiovascular Care and the European branch of the Extracorporeal Life Support Organization. The survey was available from 17 April 2023 to 23 May 2023. The target population were European clinicians involved in care for adults on pMCS. We included 105 responses from 26 European countries. Notably, 72.4% of the respondents adhered to locally established anticoagulation protocols, with unfractionated heparin (UFH) being the predominant anticoagulant (Impella™: 97.0% and V-A ECMO: 96.1%). A minority of the respondents, 10.8 and 14.5%, respectively, utilized the anti-factor-Xa assay in parallel with activated partial thromboplastin time for UFH monitoring during Impella™ and V-A ECMO support. Anticoagulant targets varied across institutions. Following acute coronary syndrome without percutaneous coronary intervention (PCI), 54.0 and 42.7% were administered dual antiplatelet therapy during Impella™ and V-A ECMO support, increasing to 93.7 and 84.0% after PCI.

CONCLUSION

Substantial heterogeneity in antithrombotic practices emerged from participants' responses, potentially contributing to variable device-associated bleeding and thrombotic complications.

Usefulness of bicarbonate-based Impella purge solution in a patient with heparin-induced thrombocytopenia: the first case report of long-term management in Japan

Percutaneous mechanical circulatory support utilizing micro-axial flow pumps, such as the Impella group of devices, has become a life-saving technique in the treatment of refractory cardiogenic shock, with ever-increasing success rates. A 30-year-old man presented with acute decompensated heart failure and a severely reduced left ventricular ejection fraction (17%). Despite initial treatment with inotropic drugs and intra-aortic balloon pump support, his hemodynamic status remained unstable. Transition to Impella CP mechanical circulatory support was made on day 6 owing to persistently low systolic blood pressure. A significant decline in platelet count prompted suspicion of heparin-induced thrombocytopenia (HIT), later confirmed by positive platelet-activated anti-platelet factor 4/heparin antibody and a 4Ts score of 6 points. Argatroban was initially used as the purge solution, but owing to complications, a switch to Impella 5.0 and a bicarbonate-based purge solution (BBPS) was performed. Despite additional veno-arterial extracorporeal membrane oxygenation support on day 24, the patient, aiming for ventricular assist device treatment and heart transplantation, died from infection and multiple organ failure. Remarkably, the Impella CP continued functioning normally until the patient's demise, indicating stable Impella pump performance using BBPS. This case highlights the usefulness of BBPS as an alternative to conventional Impella heparin purge solution when HIT occurs.

Safety and Effectiveness of an Anti-Xa-based Unfractionated Heparin Protocol for Impella Percutaneous Ventricular Assist Devices

Background: Impella devices are used for mechanical circulatory support in patients with cardiogenic shock or those undergoing high-risk percutaneous coronary intervention (PCI). Anticoagulation protocols in this population are not well established and are complicated by concomitant use of purge solutions containing unfractionated heparin (UFH) and intravenous UFH continuous infusion (CI) for systemic anticoagulation. Objectives: To evaluate thrombotic and bleeding complications when using a novel UFH protocol with a reduced initial UFH CI dose of 6 units/kg/hour targeting an anti-Xa goal of 0.3 to 0.5 units/mL in patients receiving Impella support. Methods: This single-center, retrospective study included 41 patients on Impella support who received an UFH purge solution and/or an IV UFH infusion. The primary outcome was overall composite bleeding. Secondary outcomes included thrombotic events and systemic UFH exposure. An exploratory analysis was performed to identify risk factors for bleeding. Results: Anti-Xa values were in therapeutic range 46% of the time while on support (interquartile range 16.6%-75%), with a median IV UFH dose of 6 units/kg/hour. The overall bleeding rate was 29.2%, with 6 minor bleeds and 2 major bleeds with no fatal bleeding or intracranial hemorrhage. Rate of overall thrombosis was 4.9%, including 1 ischemic stroke and 1 occurrence of limb ischemia. Conclusion: Use of a modified UFH protocol to target an anti-Xa goal of 0.3 to 0.5 units/mL resulted in bleeding and thrombotic event rates similar to previous literature. This protocol utilizing an initial rate of 6 units/kg/hour may be a useful approach to achieve therapeutic anticoagulation while accounting for UFH exposure from the purge solution and minimizing need for frequent calculations.

Heparin dosing in patients with Impella-supported cardiogenic shock

BACKGROUND

Impella™ is increasingly used in cardiogenic shock. However, thromboembolic and bleeding events are frequent during percutaneous mechanical circulatory support (pMCS).

OBJECTIVE

Therefore, we aimed to explore the optimal anticoagulation regime for pMCS to prevent thromboembolism and bleedings.

METHODS

This hypothesis-generating multi-center cohort study investigated 170 patients with left-Impella™ support. We (A) compared bleeding/thrombotic events in two centers with therapeutic range (TR-aPTT) activated partial thromboplastin time (60-80s) and (B) compared events of these centers with one center with intermediate range aPTT (40-60s).

RESULTS

After matching, there were no differences in patients' characteristics. In centers aiming at TR-aPTT, major bleeding was numerically lower with aPTT <60s within 48 h of left-Impella™ support, versus patients that achieved the aimed aPTT of ≥60s [aPTT ≥60s: 22 (37.3%) vs. aPTT<60s 14 (23.7%); Hazard ratio [HR], 0.62 (95%) CI, 0.28-1.38; p = 0.234]. Major cardiovascular and cerebrovascular adverse events (MACCE) did not differ between groups. In comparison of centers, TR-aPTT strategy showed higher major bleeding rates [TR: 8 (47.1%) vs. intermediate range: 1 (5.9%); HR, 0.06 (95%) CI, 0.01-0.45; p = 0.006]. MACCE were lower in the intermediate range aPTT group as well [TR 12 (70.6%) vs. intermediate range 5 (29.4%) HR, 0.32 (95%) CI, 0.11-0.92; p = 0.034].

CONCLUSION

This pilot analysis showed that lowering UFH-targets in left-Impella™ supported CS patients seems to be a safe and promising strategy for reducing major bleedings without increasing MACCE. This needs to be validated in larger, randomized clinical trials.

Impella Versus Intra-Aortic Balloon Pump in Patients With Cardiogenic Shock Treated With Venoarterial Extracorporeal Membrane Oxygenation: An Observational Study

BACKGROUND

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is increasingly used for patients with cardiogenic shock. Although Impella or intra-aortic balloon pump (IABP) is frequently used for left ventricular unloading (LVU) during VA-ECMO treatment, there are limited data on comparative outcomes. We compared outcomes of Impella and IABP for LVU during VA-ECMO.

METHODS AND RESULTS

Using the Nationwide Readmissions Database between 2016 and 2020, we analyzed outcomes in 3 groups of patients with cardiogenic shock requiring VA-ECMO based on LVU strategies: extracorporeal membrane oxygenation (ECMO) only, ECMO with IABP, and ECMO with Impella. Of 15 980 patients on VA-ECMO, IABP and Impella were used in 19.4% and 16.4%, respectively. The proportion of patients receiving Impella significantly increased from 2016 to 2020 (6.5% versus 25.8%; P-trend<0.001). In-hospital mortality was higher with ECMO with Impella (54.8%) compared with ECMO only (50.4%) and ECMO with IABP (48.4%). After adjustment, ECMO with IABP versus ECMO only was associated with lower in-hospital mortality (adjusted odds ratio [aOR], 0.83; P=0.02). ECMO with Impella versus ECMO only had similar in-hospital mortality (aOR, 1.09; P=0.695) but was associated with more bleeding (aOR, 1.21; P=0.007) and more acute kidney injury requiring hemodialysis (aOR, 1.42; P<0.001). ECMO with Impella versus ECMO with IABP was associated with greater risk of acute kidney injury requiring hemodialysis (aOR, 1.49; P=0.002), higher in-hospital mortality (aOR, 1.32; P=0.001), and higher 40-day mortality (hazard ratio, 1.25; P<0.001).

CONCLUSIONS

In patients with cardiogenic shock on VA-ECMO, LVU with Impella, particularly with 2.5/CP, was not associated with improved survival at 40 days but was associated with increased adverse events compared with IABP. More data are needed to assess Impella platform-specific comparative outcomes of LVU.

Sodium bicarbonate as a local adjunctive agent for limiting platelet activation, aggregation, and adhesion within cardiovascular therapeutic devices

Cardiovascular therapeutic devices (CTDs) remain limited by thrombotic adverse events. Current antithrombotic agents limit thrombosis partially, often adding to bleeding. The Impella® blood pump utilizes heparin in 5% dextrose (D5W) as an internal purge to limit thrombosis. While effective, exogenous heparin often complicates overall anticoagulation management, increasing bleeding tendency. Recent clinical studies suggest sodium bicarbonate (bicarb) may be an effective alternative to heparin for local anti-thrombosis. We examined the effect of sodium bicarbonate on human platelet morphology and function to better understand its translational utility. Human platelets were incubated (60:40) with D5W + 25 mEq/L, 50 mEq/L, or 100 mEq/L sodium bicarbonate versus D5W or D5W + Heparin 50 U/mL as controls. pH of platelet-bicarbonate solutions mixtures was measured. Platelet morphology was examined via transmission electron microscopy; activation assessed via P-selectin expression, phosphatidylserine exposure and thrombin generation; and aggregation with TRAP-6, calcium ionophore, ADP and collagen quantified; adhesion to glass measured via fluorescence microscopy. Sodium bicarbonate did not alter platelet morphology but did significantly inhibit activation, aggregation, and adhesion. Phosphatidylserine exposure and thrombin generation were both reduced in a concentration-dependent manner-between 26.6 ± 8.2% (p = 0.01) and 70.7 ± 5.6% (p < 0.0001); and 14.0 ± 6.2% (p = 0.15) and 41.7 ± 6.8% (p = 0.03), respectively, compared to D5W control. Platelet aggregation via all agonists was also reduced, particularly at higher concentrations of bicarb. Platelet adhesion to glass was similarly reduced, between 0.04 ± 0.03% (p = 0.61) and 0.11 ± 0.04% (p = 0.05). Sodium bicarbonate has direct, local, dose-dependent effects limiting platelet activation and adhesion. Our results highlight the potential utility of sodium bicarbonate as a locally acting agent to limit device thrombosis.

Anticoagulation practices and complications associated with Impella® support at an advanced cardiac center in the Middle East gulf region

Anticoagulation during Impella® support is a challenge due to its complications and inconsistent practice across the globe. This observational, retrospective chart review included all patients with Impella® support at our advanced cardiac center at a quaternary care hospital in the Middle East gulf region. The study was conducted over six years (2016-2022), a time period during which manufacturer recommendations for purge solution, anticoagulation protocols as well as Impella® place in therapy and utilization were all evolving. We aimed to evaluate the efficacy of different anticoagulation practices and association with complications and outcomes. Forty-one patients underwent Impella® during the study period, including 25 patients with support for more than 12 h, and are the focus of our analysis. Cardiogenic shock (n = 25, 60.9%) was the primary indication for Impella®, followed by facilitating high-risk PCI (n = 15, 36.7%) and left ventricular afterload reduction in patients undergoing veno-arterial extracorporeal membrane oxygenation (n = 1, 2.4%). Our overall Impella® usage evolved over the years from a primary use to facilitate a high-risk PCI to the recent more common use of LV unloading in cardiogenic shock. No patients experienced device malfunction and the incidence of other complications including ischemic stroke and bleeding were comparable to those reported in the literature (12.2% and 24% respectively). The 30-day all-cause mortality of 41 patients was 53.6%. In line with the evolving recommendations and evidence, we observed an underutilization of non-heparin-based purge solutions and inconsistent management of anticoagulation in the setting of both Impella® and VA ECMO which necessitates more education and protocols.

Outcomes of systemic bivalirudin and sodium bicarbonate purge solution for Impella 5.5

BACKGROUND

Impella 5.5 (Abiomed; Danvers, MA) (IMP5) is a commonly used, surgically implanted, tMCS device that requires systemic anticoagulation and purge solution to avoid pump failure. To avoid heparin-induced thrombocytopenia (HIT) from unfractionated heparin (UFH) use, our program has explored the utility of bivalirudin (BIV) for systemic anticoagulation and sodium bicarbonate-dextrose purge solution (SBPS) in IMP5.5.

METHODS

This single center, retrospective study included 34 patients supported on IMP5.5 with BIV based AC and SBPS between December 1st 2020 to December 1st 2021.The efficacy and safety end points were incidence of development of HIT, Tissue Plasminogen Activator (tPA) use for suspected pump thrombosis, stroke, and device failure as well as clinically significant bleeding.

RESULTS

The median duration of IMP5.5 support was 9.8 days (IQR: 6-15). Most patients were bridged to HTX (58%) followed by recovery (27%) and LVAD implantation (15%). Patients were therapeutic on bivalirudin for 64% of their IMP5.5 support. One patient (2.9%) suffered from ischemic stroke and 26.5% (9) patients developed clinically significant bleeding. tPA was administered to 7(21%) patients. One patient in the entire cohort developed HIT.

CONCLUSIONS

Our experience supports the use of systemic BIV and SBPS as a method to avoid heparin exposure in a patient population predisposed to the development of HIT.

Strategies for Reducing Vascular and Bleeding Risk for Percutaneous Left Ventricular Assist Device-supported High-risk Percutaneous Coronary Intervention

In patients at high risk for haemodynamic instability during percutaneous coronary intervention (PCI), practitioners are increasingly opting for prophylactic mechanical circulatory support, such as the Impella® heart pump (Abiomed, Danvers, MA, USA). Though Impella-supported high-risk PCI (HRPCI) ensures haemodynamic stability during the PCI procedure, access-related complication rates have varied significantly in published studies. Reported variability in complication rates relates to many factors, including anticoagulation practices, access and closure strategy, post-procedure care and variations in event definitions. This article aims to outline optimal strategies to minimize vascular and bleeding complications during Impella-supported HRPCI based on previously identified clinical, procedural and postprocedural risk factors. Practices to reduce complications include femoral skills training, standardized protocols to optimize access, closure, anticoagulation management and post-procedural care, as well as the application of techniques and technological advances. Protocols integrating these strategies to mitigate access-related bleeding and vascular complications for Impella-supported procedures can markedly limit vascular access risk as a barrier to appropriate large-bore mechanical circulatory support use in HRPCI.

What is known in pre-, peri-, and post-procedural anticoagulation in micro-axial flow pump protected percutaneous coronary intervention?

Interest in the use of percutaneous left ventricular assist devices (p-LVADs) for patients undergoing high-risk percutaneous coronary intervention (PCI) is growing rapidly. The Impella™ (Abiomed Inc.) is a catheter-based continuous micro-axial flow pump that preserves haemodynamic support during high-risk PCI. Anticoagulation is required to counteract the activation of the coagulation system by the patient’s procoagulant state and the foreign-body surface of the pump. Excessive anticoagulation and the effect of dual antiplatelet therapy (DAPT) increase the risk of bleeding. Inadequate anticoagulation leads to thrombus formation and device dysfunction. The precarious balance between bleeding and thrombosis in patients with p-LVAD support is often the primary reason that patients’ outcomes are jeopardized. In this chapter, we will discuss anticoagulation strategies and anticoagulant management in the setting of protected PCI. This includes anticoagulant therapy with unfractionated heparin, direct thrombin inhibitors, DAPT, purge blockage prevention by bicarbonate-based purge solution, and monitoring by activated clotting time, partial thromboplastin time, as well as anti-factor Xa levels. Here, we provide a standardized approach to the management of peri-interventional anticoagulation in patients undergoing protected PCI.

Position Statement on Vascular Access Safety for Percutaneous Devices in AMI Complicated by Cardiogenic Shock

In the United States, the frequency of using percutaneous mechanical circulatory support devices for acute myocardial infarction complicated by cardiogenic shock is increasing. These devices require large-bore vascular access to provide left, right, or biventricular cardiac support, frequently under urgent/emergent circumstances. Significant technical and logistical variability exists in device insertion, care, and removal in the cardiac catheterization laboratory and in the cardiac intensive care unit. This variability in practice may contribute to adverse outcomes observed in centers that receive patients with cardiogenic shock, who are at higher risk for circulatory insufficiency, venous stasis, bleeding, and arterial hypoperfusion. In this position statement, we aim to: 1) describe the public health impact of bleeding and vascular complications in cardiogenic shock; 2) highlight knowledge gaps for vascular safety and provide a roadmap for a regulatory perspective necessary for advancing the field; 3) propose a minimum core set of process elements, or "vascular safety bundle"; and 4) develop a possible study design for a pragmatic trial platform to evaluate which structured approach to vascular access drives most benefit and prevents vascular and bleeding complications in practice.

Impella Management for the Cardiac Intensivist

The Impella mechanical circulatory support (MCS) system is a catheter-based continuous flow cardiac assist device that is widely used in the treatment of cardiogenic shock in medical and surgical cardiac intensive care units. As with all forms of MCS, device-related complications remain a major concern, the incidence of which can be mitigated by adhering to a few fundamental concepts in device management. The purpose of this review is to comprehensively describe our strategy for managing, repositioning, and weaning the Impella catheter.

Anticoagulation for Percutaneous Ventricular Assist Device-Supported Cardiogenic Shock: JACC Review Topic of the Week

Interest in the use of mechanical circulatory support for patients presenting with cardiogenic shock is growing rapidly. The Impella (Abiomed Inc), a microaxial, continuous-flow, short-term, ventricular assist device (VAD), requires meticulous postimplantation management. Because systemic anticoagulation is needed to prevent pump thrombosis, patients are exposed to increased bleeding risk, further aggravated by sepsis, thrombocytopenia, and high shear stress-induced acquired von Willebrand syndrome. The precarious balance between bleeding and thrombosis in percutaneous VAD-supported cardiogenic shock patients is often the main reason that patient outcomes are jeopardized, and there is a lack of data addressing optimal anticoagulation management strategies during percutaneous VAD support. Here, we present a parallel anti-Factor Xa/activated partial thromboplastin time-guided anticoagulation algorithm and discuss pitfalls of heparin monitoring in critically ill patients. This review will guide physicians toward a more standardized (anti)coagulation approach to tackle device-related morbidity and mortality in this critically ill patient group.

Antithrombotic management for Impella® temporary ventricular assist devices: An analysis of an academic health-system experience

The use of acute mechanical circulatory support (MCS) has increased over the last decade. For patients with left-ventricular failure, an Impella^® (Abiomed, Danvers, MA) may be used to improve cardiac output. The purpose of this study is to describe Impella^® anticoagulation patterns and evaluate the safety and effectiveness of our protocol. This is a retrospective review of all adult patients who required at least 24 h of Impella^® support and received a heparin-based purge solution. In total, 109 patients were included in the final analysis. The most common indication for Impella^® device insertion was cardiogenic shock (76%) with the remaining patients receiving a device for a high-risk procedures; typically coronary artery bypass grafting or percutaneous coronary intervention. A total of 9 thrombotic events occurred among 8 (7%) patients and 50 bleeding events occurred among 43 (39%) patients, with the most common classification being BARC 3a (60%). A univariate analysis revealed that patients were more likely to bleed if they were less than 65 years old, had an indication of cardiogenic shock for Impella^®, inserted the device peripherally, were on dual antiplatelet therapy, or had an intra-aortic balloon pump prior to Impella^® insertion, the latter of which was confirmed with a multivariate analysis (OR 2.5 [1.072-5.830]; p = 0.034). For those monitored by anti-Xa, the presence of two or more values greater than 0.40 IU/mL was a risk factor for bleeding (p = 0.037). Our study identifies risk factors for bleeding in patients receiving temporary MCS with an Impella^®.

A Multidisciplinary Educational Approach to Anticoagulation Management for a Percutaneous Endovascular Mechanical Circulatory Support Device

Background

Anticoagulation (AC) management of the Impella varies considerably among treatment centers. Published data regarding the management of complications including heparin-induced thrombocytopenia, bleeding and thrombosis are limited.

Objective

A multidisciplinary team was assembled to 1) identify baseline knowledge of nurses and pharmacists involved in Impella anticoagulation management; 2) develop an educational tool specific to Impella anticoagulation; 3) reassess knowledge following implementation of the tool.

Methods

A team consisting of pharmacists, nurses and a physician developed surveys that were subsequently distributed to 28 nurses and 17 pharmacists. Survey questions measured knowledge in 4 areas of anticoagulation management: product selection, administration, monitoring and therapeutic recommendation. A pocket card containing flow diagrams for Impella anticoagulation management was developed. Following distribution of the card and education on its application, surveys were redistributed to measure the change in knowledge.

Results

The frequency (%) of correct answers for all survey questions for both pharmacists and nurses significantly increased from 38% to 84% (p < 0.00001) and 63% to 93% (p < 0.00001), respectively. Substantial increases in the frequency of correct answers in the majority of question categories were observed for both pharmacists and nurses postintervention.

Conclusion and Relevance

Using a multidisciplinary approach, an institution-specific pocket card addressing the complexities of Impella anticoagulation was developed. Following dissemination of the card and education on its application, improved knowledge across the scope of Impella anticoagulation management was observed in both pharmacists and nurses.

Optimizing anticoagulation for patients receiving Impella support

Anticoagulation of patients treated with the Impella percutaneous mechanical circulatory support (MCS) devices is complex and lacks consistency across centers, potentially increasing the risk of complications. In order to optimize safety and efficacy, an expert committee synthesized all available evidence evaluating anticoagulation for patients receiving Impella support in order to provide consensus recommendations for the management of anticoagulation with these devices. The evidence synthesis led to the creation of 42 recommendations to improve anticoagulation management related to the use of the Impella devices. Recommendations address purge solution management, intravenous anticoagulation, monitoring, evaluation and management of heparin-induced thrombocytopenia (HIT), and management during combination MCS support. The use of a heparinized, dextrose-containing purge solution is critical for optimal device function, and a bicarbonate-based purge solution may be an alternative in certain situations. Likewise, intravenous (ie, systemic) anticoagulation with heparin is often necessary, although evidence supporting the optimal assay and target range for monitoring the level of anticoagulation is generally lacking. Patients treated with an Impella MCS device may develop HIT, which is more difficult to evaluate and treat in this setting. Lastly, the use of Impella with extracorporeal membrane oxygenation or for biventricular support creates additional anticoagulation challenges.

Use of a novel bicarbonate-based Impella 5.5 purge solution in a coagulopathic patient

The Impella 5.5 with Smart Assist (Abiomed) is a life-saving treatment option in acute heart failure which utilizes a continuous heparin purge solution to prevent thrombosis. In patients with contraindications to heparin, alternative anticoagulation strategies are required. We describe the stepwise management of anticoagulation in a coagulopathic patient with persistent cardiogenic shock following a coronary artery bypass procedure who underwent Impella 5.5 placement. A direct thrombin inhibitor-based purge solution was utilized while evaluating for heparin-induced thrombocytopenia. The use of a novel bicarbonate-based purge solution (BBPS) was successfully used due to severe coagulopathy. There were no episodes of pump thrombosis or episodes of severe bleeding on the BBPS and systemic effects of alkalosis and hypernatremia were minimal.

Use of an argatroban systemic infusion and purge solution in a patient with a percutaneous ventricular assist device with suspected heparin-induced thrombocytopenia

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PURPOSE

Thrombocytopenia can occur when using an Impella percutaneous ventricular assist device (pVAD), and heparin-induced thrombocytopenia (HIT) is often suspected. Data on heparin- and anticoagulant-free purge solutions in these devices are limited. Previous case reports have described argatroban-based purge solutions, both with and without systemic argatroban, at varying concentrations in patients with known or suspected HIT.

SUMMARY

A 33-year-old male was transferred to our institution and emergently initiated on life support with venoarterial extracorporeal membrane oxygenation (ECMO), an Impella pVAD, and continuous venovenous hemofiltration to receive an urgent aortic valve replacement. Over the next several days, the patient's platelet count declined with a nadir of 17 × 10 3/µL on hospital day 13. The patient's 4T score for probability of HIT was calculated as 4. All heparin products were discontinued on hospital day 15, and the patient was initiated on systemic infusion with argatroban 1,000 µg/mL at a rate of 0.2 µg/kg/min with a purge solution of argatroban 0.05 mg/mL. The systemic infusion remained at a rate of 0.2 µg/kg/min, and the total argatroban dose was, on average, less than 0.25 µg/kg/min. On hospital day 21, the patient was transferred to another institution.

CONCLUSION

Systemic infusion and a purge solution with argatroban were used in a patient with an Impella pVAD with multisystem organ dysfunction and suspected HIT. The patient achieved therapeutic activated partial thromboplastin times without adjustment of the systemic argatroban infusion and did not experience bleeding or thrombosis. Further studies concerning the safety and effectiveness of argatroban-based purge solutions in patients with pVADs are needed.

Joint EAPCI/ACVC expert consensus document on percutaneous ventricular assist devices

There has been a significant increase in the use of short-term percutaneous ventricular assist devices (pVADs) as acute circulatory support in cardiogenic shock and to provide haemodynamic support during interventional procedures, including high-risk percutaneous coronary interventions. Although frequently considered together, pVADs differ in their haemodynamic effects, management, indications, insertion techniques, and monitoring requirements. This consensus document summarizes the views of an expert panel by the European Association of Percutaneous Cardiovascular Interventions (EAPCI) and the Association for Acute Cardiovascular Care (ACVC) and appraises the value of short-term pVAD. It reviews the pathophysiological context and possible indications for pVAD in different clinical settings and provides guidance regarding the management of pVAD based on existing evidence and best current practice.

Impact of the whole activated clotting time during Impella support on short-term prognosis

Impella (Abiomed, Danvers, MA, USA) is a percutaneous trans-catheter left ventricular assist device. Anticoagulant therapy targeting whole activated clotting time (ACT) between 160 and 180 s is recommended to prevent pump thrombosis during support. However, we sometimes experience fatal bleeding despite achieving the target ACT range. Consecutive patients who received Impella support in our institute between March 2018 and October 2020 were included in this retrospective study. The association between the averaged ACT levels during the Impella support and 30-day mortality was investigated. A total of 36 patients (71 years old, 61% males) were included. Most of the patients were managed within the recommended therapeutic range of ACT, and the average ACT level was 162 s. The higher ACT group (> 168 s) had older age, smaller body mass index, and higher serum creatinine compared with the lower ACT group (p < 0.05 for all). A higher ACT level was an independent risk factor of 30-day mortality with an adjusted hazard ratio of 1.085 (95% confidence interval 1.037-1.154) with a cut-off level of 168 s. There were only two thromboembolic events. Patients managed with higher ACT levels had a higher risk of 30-day mortality during Impella support. A low-dose heparin purge solution might be recommended in patients with high-risk for bleeding events.

Bivalirudin as a Systemic Anticoagulant and Flush Solution Additive for Sequential Mitral and Tricuspid Valve Percutaneous Edge-to-Edge Repair in a Patient With Heparin-Induced Thrombocytopenia

Herein the case of a patient with a prior history of heparin-induced thrombocytopenia who underwent percutaneous mitral valve edge-to-edge repair that was followed by a tricuspid edge-to-edge repair two months later is presented. Recommendations exist for systemic anticoagulant alternatives for percutaneous mitral valve edge-to-edge repair with the MitraClip device (Abbott, Chicago, IL), but minimal guidance and experience are present regarding alternative systemic anticoagulation during the performance of right-sided interventions, including tricuspid edge-to-edge repair (TriClip; Abbott). Notably, there is no clear consensus regarding the use of an alternative anticoagulant in the catheter flush solution for the delivery systems used during these procedures, particularly for right-sided interventions.

Safety and Efficacy of a Percutaneously Inserted Ventricular Support Device Purge Solution Heparin 25 U/mL

Background:

The Impella is a percutaneous ventricular assist device (pVAD) that provides temporary hemodynamic support to patients with cardiogenic shock or for protected percutaneous coronary intervention. The manufacturer recommends a 50-U/mL concentration of heparin purge solution (or 25 U/mL as an alternative), with systemic heparin to maintain therapeutic anticoagulation during device support. Concomitant use of systemic heparin with the purge solution may increase the risk of bleeding.

Objectives:

The primary objective of this study was to describe the prevalence of thrombosis and bleeding using a less-concentrated heparin purge solution (25 U/mL) in combination with systemic heparin therapy.

Methods:

This was a retrospective observational cohort study of patients who required at least 12 hours of pVAD support and received 25-U/mL concentration of heparin purge solution between January 1, 2014, and May 31, 2017. The primary end points were the rate of thrombotic and bleeding events. Secondary end points included the percentage of time within the therapeutic activated partial thromboplastin time (aPTT) range. Descriptive statistics were utilized for data analysis.

Results:

Of the 161 patients screened, 100 met inclusion criteria; 63% of patients experienced a bleeding event, with Bleeding Academic Research Consortium (BARC) type 3a being the most common. Median percentages of subtherapeutic and supratherapeutic aPTT values were similar between the bleeding and nonbleeding groups. Two patients experienced thrombotic events.

Conclusion and Relevance:

Based on our findings, the device thrombosis rate was 2% and the rate of major bleeding (BARC 3a and higher) was 35%. This study provides descriptive outcomes data of a lower-concentration heparin purge solution.

Anticoagulation Management for Impella Percutaneous Ventricular Assist Devices: An Analysis of a Single-Center Experience

BACKGROUND

Impella devices offer temporary mechanical circulatory support for cardiogenic shock. The manufacturer recommends systemic anticoagulation with a target activated clotting time of 160 to 180 s but provides no guidance on how to manage both the heparinized purge solution and the additional intravenous heparin needed to reach this therapeutic range. Previous publications demonstrated a lack of standardization in heparin management for Impella devices.

OBJECTIVE

The purpose of this study was to compare the effectiveness and safety of 2 different heparin protocols for long-term Impella support.

METHODS

This single-center, retrospective study included adult patients on Impella support for greater than 24 hours. The primary end point was time to therapeutic range measured in hours, from time of implantation to the first of 2 consecutive measurements within the therapeutic range. Secondary end points included percentage of time in therapeutic range, rates of major bleeding, pump thrombosis, hemolysis, and nursing satisfaction.

RESULTS

There were 19 patients identified, with 7 using the original protocol and 12 using the revised protocol. Time to therapeutic range was similar between protocols (15.5 vs 12 hours, P = NS). Another 14 patients were managed with patient-specific protocols as a result of bleeding or physician preference. In total, 42% of all patients in this study experienced major bleeding. There were no confirmed thrombosis events. This study was limited by a small sample size.

CONCLUSION AND RELEVANCE

Despite using different heparin protocols, outcomes and bleeding events were similar between groups. Future studies are needed to determine the optimal degree of anticoagulation necessary to reduce bleeding risk.