CHA2DS2-VASc score stratifies mortality risk in patients with and without atrial fibrillation

ObjectivesThe CHA2DS2-VASc score is the preferred risk model for anticoagulation decision-making in atrial fibrillation (AF) patients. Recent studies have found this score to have prognostic value in other cardiovascular diseases. We assessed the relationships between CHA2DS2-VASc score and long-term mortality in adults referred for stress testing,Methods165 184 consecutive patients from January 1991 to December 2014 from a prospective registry were studied, with CHA2DS2-VASc score calculated for all patients, and AF and anticoagulation status were recorded. The primary endpoint was all-cause mortality.ResultsIn this cohort, 12 450 (7.5%) patients had AF and mean CHA2DS2-VASc score was 2.2±1.2. There were 22 152 (18.4%) deaths during mean follow-up of 6.1±4.8 years. In multivariable analysis, CHA2DS2-VASc score, presence of AF and anticoagulation use, along with end-stage renal failure and smoking were all independently associated with mortality with HRs (95% CIs) of 1.23 (1.21 to 1.25), 1.18 (1.10 to 1.27) and 1.50 (1.40 to 1.60), respectively. Higher CHA2DS2-VASc score was incrementally associated with worse survival both in patients with and without AF (log-rank p<0.001). Anticoagulation use was associated with reduced survival in non-AF patients with alternative anticoagulation indications at all CHA2DS2-VASc score categories, and AF patients with lower CHA2DS2-VASc score 0–2, but was protective in AF patients with higher CHA2DS2-VASc score 4–9.ConclusionIncrementally higher CHA2DS2-VASc score, a simple clinical tool, is associated with mortality in patients regardless of presence of AF and anticoagulation status. Anticoagulation use was associated with worse survival in non-AF patients and AF patients with low CHA2DS2-VASc scores, but was protective in AF patients with high CHA2DS2-VASc scores.

Use of a Novel Bicarbonate-Based Impella 5.5 Purge Solution in a Coagulopathic Patient

The Impella 5.5 with SmartAssist (Abiomed; Danvers, MA) 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. 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.

MO871HEPARIN INDUCED THROMBOCYTOPENIA AND HEMODIALYSIS - SINGLE CENTRE EXPERINCE

Background and Aims Heparin-induced thrombocytopenia (HIT) is a potentially fatal adverse reaction after administration of unfractionated or fractionated heparin, which underlies the generation of antibodies to the heparin complex and platelet factor 4 (PF4). It occurs in 5% of patients treated with unfractionated heparin and 0.5 - 1.5% fractionated heparin. The aim of the study is to determine the incidence and outcome of hemodialysis patients with HIT over 4-years period. Method This retrospective study analyzed patients who were tested for evidence of positive anti-heparin antibody in the period from 2015 to 2020 in Zvezdara University Medical Center. The diagnosis was confirmed by the 4T clinical scoring system, a positive antiheparin-PF4 ELISA test and a positive platelet aggregation test with heparin. Results During observation period, total of 64 tests were performed, out of which 23 patients were positive. Out of them, 14 patients were on HD, 7 patients (geriatric, surgery and cardiology departments) received therapy due to peripheral thrombosis, AIM or arrhythmia and 2 patients during 2020 due to SARS-CoV-2 bilateral pneumonia. All patients treated at nephrology, started hemodialysis (HD) with unfractionated heparin, while others were treated with LMWH. 4T scoring showed that 64% of patients had a moderate risk of developing HIT, while high risk was assessed in 36% of patients. Thrombotic complications in the form of deep venous thrombosis had 53% of patients and pulmonary thromboembolism had 17,5 % of patients. The greatest decrease in Tr was the most commonly observed between 10th and 14th day (61% of patients) and 39% from 4th to 10th day from start of heparin administration. In addition to heparin withdrawal and treatment with alternative non-heparin anticoagulation (fondaparinoux), 7 patients needed plasma treatment. 11 patients on HD were transferred to peritoneal dialysis (PD), and 3 patients recovered renal function. Overall mortality was 52%, and it was below 30% in hemodialysis patients. Conclusion HIT should be considered in patients at risk. It is necessary to abolish heparin treatment and use alternative method (PD) or alternative anticoagulation. Hemodialysis patients have better prognosis than other comparable patients

A Scoping Review of Alternative Anticoagulation Strategies for Hemodialysis Patients with a Mechanical Heart Valve

<b><i>Introduction:</i></b> Patients with end-stage renal disease (ESRD) have high rates of cardiac valvulopathy but can develop contraindications for vitamin K antagonist (VKA) therapy. We explored the evidence for alternative anticoagulation strategies in patients with ESRD with a contraindication for VKA therapy. <b><i>Methods:</i></b> A scoping review was completed, searching MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and Conference abstracts from inception to March 30, 2021. The study population was patients with ESRD who were on VKA therapy and developed a contraindication to VKA therapy use. All data regarding studies, patient characteristics, anticoagulation strategy, and clinical outcomes were summarized. <b><i>Results:</i></b> Twenty-three articles met inclusion criteria. These articles included 57 patients. Contraindications to VKA therapy included calcific uremic arteriolopathy (CUA) (<i>n</i> = 55) and warfarin-induced skin necrosis (<i>n</i> = 2). All studies were either case reports or case series. There were 10 anticoagulation strategies identified. Continuation of VKA therapy was associated with increased death and decreased rates of CUA resolution (80.0% and 10.0%, respectively), compared to apixaban (24.0% and 70.8%), subcutaneous (SC) low-molecular-weight heparin (LMWH) (14.3%, 85.7%), and SC unfractionated heparin (0.0%, 100.0%). While only 5 patient cases were reported with mechanical heart valves, SC LMWH use has been reported in this context with good outcomes. <b><i>Conclusions:</i></b> In patients with ESRD who develop a contraindication to VKA therapy, several alternative anticoagulation strategies have been reported with superior outcomes to VKA continuation. While outcomes appear superior to continuation of VKA therapy, more data are required before definitive recommendations can be made for the patient with ESRD and a mechanical heart valve.

P1510INCIDENCE AND OUTCOME HEMODIALYSIS PATIENCE WITH HEPARIN INDUCED THROMBOCYTOPENIA - FOUR YEAR EXPERIENCE ZVEZDARA UNIVERSITY MEDICAL CENTER

Background and Aims Heparin-induced thrombocytopenia (HIT) is a potentially fatal adverse reaction after administration of unfractionated or fractionated heparin, which underlies the generation of antibodies to the heparin complex and platelet factor 4 (PF4). It occurs in 5% of patients treated with unfractionated heparin and 0.5 - 1.5% fractionated heparin. The aim of the study is to determine the incidence and outcome of hemodialysis patients with HIT over 4 years period. Method Our retrospective study analyzed patients who were tested for evidence of positive anti-heparin antibody in the period from 2015 to 2019 in Zvezdara University Medical Center. The diagnosis was confirmed by the 4T clinical scoring system, a positive antiheparin-PF4 ELISA test and a positive platelet aggregation test with heparin. Results During observation period, total of 54 tests were performed on HIT suspected patients, out of which 21 patients were positive. Out of them, 14 patients were on HD, and other 7 (geriatric, surgery and cardiology departments) received therapy due to peripheral thrombosis, AIM or arrhythmia. All patients treated at nephrology, started hemodialysis (HD) with unfractionated heparin, while others were treated with LMWH. 4T scoring showed that 64% of patients had a moderate risk of developing HIT, while high risk was assessed in 36% of patients. Thrombotic complications in the form of deep venous thrombosis had 50% of patients, pulmonary thromboembolism had 11% of patients. The greatest decrease in Tr was most commonly observed between 10th and 14th day (61% of patients) and 39% from 4th to 10th day from start of heparin administration. In addition to heparin withdrawal and treatment with alternative nonheparin anticoagulation (fondaparinoux), 5 patients needed plasma treatment. 11 patients on HD were transferred to peritoneal dialysis (PD), and 2 patients recovered renal function. Overall mortality was 52%, while in nephrology patients was below 30%. Conclusion HIT should be considered in patients at risk. It is necessary to abolish heparin treatment and use alternative method (PD) or alternative anticoagulation. Hemodialysis patients have better prognosis than other comparable patients.

Heparin-induced thrombocytopenia (HIT): Review of incidence, diagnosis, and management

Heparin-induced thrombocytopenia (HIT) is a life and limb-threatening complication of heparin exposure. Here, we review the pathogenesis, incidence, diagnosis, and management of HIT. The first step in thwarting devastating complications from this entity is to maintain a high index of clinical suspicion, followed by an accurate clinical scoring assessment using the 4Ts. Next, appropriate stepwise laboratory testing must be undertaken in order to rule out HIT or establish the diagnosis. In the interim, all heparin must be stopped immediately, and the patient administered alternative anticoagulation. Here we review alternative anticoagulation choice, therapy alternatives in the difficult-to-manage patient with HIT, and the problem of overdiagnosis.

A structured algorithm for judicious use of antibody test in diagnosis of heparin-induced thrombocytopenia (HIT).

314 Background: HIT diagnosis combines 4T scoring & HIT antibodies (HIT-Ab) testing, with confirmatory serotonin release assay (SRA). Latex immunoturbidometric assay (LIA) shows promise in quick & accurate HIT diagnosis, compared to particle immunofiltration assay (PIFA). We designed a HIT workflow & replaced PIFA with LIA at our hospital, to improve 4T usage rates & HIT diagnosis accuracy in a cost-efficient manner. Methods: In phase I, patients (pts) charts with HIT-Ab (PIFA) ordered between Mar2017-Mar2018 were retrospectively reviewed. Three investigators independently calculated 4T & reviewed PIFA/SRA results, with any alternative anticoagulation (AC) used. In phase II, a new workflow on electronic health record incorporating 4T algorithm with HIT-Ab test order was implemented. Our lab replaced PIFA with LIA. In phase II, charts for pts with LIA results from Jan-Mar 2019 were reviewed. Results: In phase I, 170 pts had PIFA results & 5 such pts (0.02%) had 4T score documented in chart. Per investigators, 113 (66.4%) pts had 4T scores. PIFA showed 60% sensitivity & 50% specificity compared to SRA. 19 pts received AC (4 pts had low 4T with negative PIFA). In phase II, 40 pts with LIA tested, 4T scoring by ordering physicians improved to 100%. Per investigators, 42.5% pts had low 4T scores. Clinicians documented high 4T in 11 pts; investigators confirmed high 4T in 2 pts. AC was used in 5 pts (4 with intermediate-high 4T per investigators) Conclusions: Our study showed that incorporation of 4T scoring in HIT algorithm significantly reduced unnecessary ordering of HIT-Ab, with 100% compliance in 4T reporting. Use of AC was consistent with the level of probability by 4T. Further clinician education can help in reduction of up scoring of 4T noted in our results. [Table: see text]

Enforcing the 4T: Including a Hard Stop 4T Calculator into the Electronic Medical Record for Heparin Induced Thrombocytopenia

Background: Among many causes of thrombocytopenia acquired during hospitalization, heparin-induced thrombocytopenia (HIT), an immune complex-mediated thrombogenic state with high morbidity and mortality, is one of the most feared etiologies. The clinical '4T' score is an established method to assess risk for HIT and guide immediate management(Lo, Juhl et al. 2006). However, the 4T score is not consistently used by clinicians, leading to potential over-testing and suboptimal management of suspected HIT. Our objective in this Quality Improvement (QI) project was to implement a mandatory 4T calculator (4TC) into the electronic medical record (EMR) to improve the positive predictive value of HIT antibody (HITA) testing, decrease the incidence of testing of low-risk patients, and to improve clinical management of suspected HIT. Methods: We developed a 4TC that assisted clinicians by integrating EMR-derived data on heparin exposure and the five most recent platelet counts with a link to an online calculator as well as clinical suggestions (Figure). As a part of this QI project, clinicians were required to enter the calculated 4T score before ordering a polyspecific HITA assay, which serves as the screening test for HIT in our institution. We reviewed laboratory records for all HITA tests performed over a six-month period, including 3 months before and after the implementation of a "hard stop" for HITA order in the EMR. We extracted data on the ordering hospital service team, 4T score documented in notes (if any), as well as quality of care indicators including rates of clinically recommended heparin cessation and initiation of alternative anticoagulation in the subgroup of patients with intermediate or high 4T score at the time of HITA order. In this QI project, we refrained from any statistical testing and summarized pre-specified outcome measures: incidence of HITA testing, positive predictive value of the HITA assay, and quality of care indicators. Results: We identified 99 (53 prior to the 4TC and 46 post) cases of HITA orders in the study period, among which there were 4 cases of confirmed HIT (either with positive IgG or positive serotonin-release assay [SRA]). Three HIT cases occurred after the 4TC was implemented. After the implementation of the 4TC, the positive predictive value for the HITA assay increased from 9% to 21%. The rate of clinically appropriate heparin order discontinuation increased from 72% to 88%, as did the initiation of alternative anticoagulation from 14% to 27%. HITA assay was most commonly ordered by the internal medicine service (35% of tests), non-cardiac intensive care service (30%), coronary care and cardiothoracic surgery services (21%), neurology (5%), and general surgery/other services (9%). Implementation of the 4TC did not significantly change this distribution, but the overall incidence of HITA orders decreased from 4.0 to 3.4 per 1000 admissions. We observed a high frequency of confirmatory SRA testing requested (18%), which is the reflex confirmatory test performed at our institution, even in cases of negative polyspecific HITA or HIT IgG. Conclusions: Addition of a 4T score calculator into the EMR which provides immediate feedback on patient's prior heparin exposure and recent platelet counts allows clinicians to consistently use the 4T score when considering HIT. Importantly, it also helps to educate non-hematologists on the proper management of HIT. Improved predictive value of the HITA assay suggests that our 4TC led to ordering HITA in a more appropriate patient population. We also demonstrated improved quality of care for suspected HIT, with increased rates of heparin cessation and initiation of alternative anticoagulation in patients with intermediate or high pre-test probability. Identifying clinical teams that order a disproportionate number of HITA assays will help us to direct education to improve clinical management. This QI project has led to other areas of improvement, particularly with regard to rational ordering of the SRA. At only three months of review since implementation of the 4TC, we have noted an improvement in the management of suspected HIT and a slight reduction in the incidence of testing. With continued review, we hope to demonstrate further improvement, as practitioners continue to use the 4TC and rely on clinical rationale rather than reflexive laboratory testing when evaluating thrombocytopenia in the hospital. Disclosures Olszewski: TG Therapeutics: Research Funding; Spectrum Pharmaceuticals: Consultancy, Research Funding; Genentech: Research Funding. Reagan:Alexion: Honoraria; Takeda Oncology: Research Funding; Pfizer: Research Funding.

Heparin-induced thrombocytopenia complicating extracorporeal membrane oxygenation support in pediatric patients: review of the literature and alternative anticoagulants

Heparin-induced thrombocytopenia (HIT) is a prothrombotic, immune-mediated complication of unfractionated heparin (UFH) and low molecular weight heparin therapy. HIT is characterized by moderate thrombocytopenia 5-10 days after initial heparin exposure, detection of platelet-activating anti-platelet factor 4/heparin antibodies and an increased risk of venous and arterial thrombosis. Extracorporeal membrane oxygenation (ECMO) is a form of mechanical circulatory support used in critically ill patients with respiratory or cardiac failure. Systemic anticoagulation is used to alleviate the thrombotic complications that may occur when blood is exposed to artificial surfaces within the ECMO circuit. Therefore, when HIT complicates patients on ECMO support, it is associated with a high thrombotic morbidity and mortality. The following article reviews the current knowledge in pediatric HIT, especially in ECMO patients, and the alternative anticoagulation options in the presence of HIT.