Administration Of Unfractionated Heparin Research Articles

Strategy to optimize PeriproCeduraL AnticOagulation in structural transseptal interventions: Design and rationale of the STOP CLOT trial

Both transcatheter edge-to-edge repair (TEER) of mitral regurgitation or left atrial appendage closure (LAAC) require periprocedural anticoagulation with unfractionated heparin (UFH) that is administered either before or immediately after transseptal puncture (TSP). The optimal timing of UFH administration (before or after TSP) is unknown. The Strategy To Optimize PeriproCeduraL AnticOagulation in Structural Transseptal Interventions trial (STOP CLOT Trial) was designed to determine if early anticoagulation is effective in reducing ischemic complications without increasing the risk of periprocedural bleeding.The STOP CLOT trial is a multicenter, prospective, double-blind, placebo-controlled, randomized trial. A total of 410 patients scheduled for TEER or LAAC will be randomized 1:1 either early UFH administration (iv. bolus of 100Units/kg UFH or placebo, given after obtaining femoral vein access and at least 5 minutes prior to the start of the TSP) or late UFH administration (iv. bolus of 100Units/kg UFH or placebo given immediately after TSP). Prespecified preliminary statistical analysis will be performed after complete follow-up of the first 196 randomized subjects. To ensure blinding, a study nurse responsible for randomization and UFH/placebo preparation is not involved in the care of the patients enrolled into the study. The primary study endpoint is a composite of (1) major adverse cardiac and cerebrovascular events (death, stroke, TIA, myocardial infarction, or peripheral embolization) within 30 days post-procedure, (2) intraprocedural fresh thrombus formation in the right or left atrium as assessed with periprocedural transesophageal echocardiography, or (3) occurrence of new ischemic lesions (diameter ≥4 mm) on brain magnetic resonance imaging performed 2-5 days after the procedure. The safety endpoint is the occurrence of moderate or severe bleeding complications during the index hospitalization. Protocols of periprocedural anticoagulation administration during structural interventions have never been tested in a randomized clinical trial. The Stop Clot trial may help reach consensus on the optimal timing of initiation of periprocedural anticoagulation.

Prevention of symptomatic pulmonary embolism for gynecologic malignancies with preoperative asymptomatic venous thromboembolism: GOTIC-VTE trial.

In Japan, perioperative prophylaxis of pulmonary embolism (PE) in gynecologic cancer patients with preoperative asymptomatic venous thromboembolism (VTE) has not been well established yet. The GOTIC-VTE trial was a prospective, multi-center, single-arm clinical trial to investigate the prevention of postoperative symptomatic PE onset by seamless anticoagulant therapy from the preoperative period to 4 weeks after surgery instead of using intermittent pneumatic compression. Anticoagulant therapy was started immediately after asymptomatic VTE diagnosis and stopped preoperatively according to the rules of each institution. Unfractionated heparin administration was resumed within 12 hours postoperatively, and this was followed by the switch to low-molecular-weight heparin and subsequently, edoxaban; this cycle was continued for 28 days. Primary outcome was the occurrence of symptomatic PE in 28 days postoperatively. Secondary outcomes were the incidence of VTE-related events in 28 days and 6 months postoperatively and protocol-related adverse events. Between February 2018 and September 2020, 99 patients were enrolled; of these, 82 patients were assessed as the full analysis set, including 58 for ovarian cancer, fallopian tube, or peritoneal cancer; 21 for endometrial cancer; and 3 for cervical cancer. No symptomatic PE was observed within 28 days postoperatively; two patients had bleeding events (major bleeding and clinically relevant nonmajor bleeding) and three had grade 3 adverse events (increased alanine transaminase, aspartate aminotransferase, or gamma-glutamyl transferase). The multifaceted perioperative management for gynecologic malignancies with asymptomatic VTE effectively prevented postoperative symptomatic PE. JRCT Identifier: jRCTs031180124.

Fresh Frozen Plasma Versus Solvent Detergent Plasma for Cardiopulmonary Bypass Priming in Neonates and Infants Undergoing Cardiac Surgery: A Retrospective Cohort Study

ObjectiveCompared with Fresh Frozen Plasma (FFP), Omniplasma has been attributed to an increased coagulation potential and an increased fibrinolytic potential. This study aimed to compare Omniplasma and FFP used for cardiopulmonary bypass (CPB) priming regarding the incidence of post-operative thrombotic-or haemorrhagic complications and outcome in paediatric patients undergoing cardiac surgery. DesignA retrospective observational cohort study SettingThis single-center study was performed in the University Medical Center Groningen ParticipantAll paediatric patients up to 10 kg undergoing cardiac surgery with CPB. InterventionsProcedures where FFP was used for CPB priming were compared with those where Omniplasma was used. Measurements and main resultsThe primary outcome parameter was a composite endpoint consisting of 1) Paediatric Intensive Care Unit (PICU) mortality, 2) thromboembolic complications, and 3) haemorrhagic complications during PICU stay. We included 143 procedures in the analyses, 90 (63%) in the FFP- and 53 (37%) in the Omniplasma-group. The occurrence of the combined primary endpoint (FFP 20% vs omniplasma 11%, p=0.18 and its components did not differ between the used CPB priming agent). Omniplasma for CPB priming was associated with decreased Unfractionated Heparin administration per kg bodyweight (585 IU vs 510 IU, p=0.03), a higher pre- and post-operative Activated Clotting Time (ACT) discrepancy (90% vs 94%, p=0.03), a lower post-operative ACT value (125 seconds vs 118 seconds, p=0.01), and less Red Blood Cell transfusion per kilogram bodyweight (78 ml vs. 55 ml, p=0.02). However, none of the variables differed statistically significant in the multivariate logistic regression analyses. ConclusionsWe did not find an association between the used plasma for CPB priming and thromboembolic, haemorrhagic complication, and death in neonates and infants undergoing cardiac surgery. Omniplasma seems to be safe to use in this population.

Increased Antithrombotic Properties of Unfractionated Heparin in Rats Following Oral Administration of Multiple Doses and Its Correlation with Endothelial Heparin Concentration

In a rat model of venous thrombosis, a single oral dose of 7.5mg kg-1 of Unfractionated Heparin (UFH) lowers thrombosis by 50%. Since clinical long-term use is necessary, our goals were to investigate the antithrombotic effects of repeated oral UFH administration. Rats were given three doses of 7.5mg kg-1 every 12, 24, 48, and 72 hours apart—as well as three or fifteen doses of 1 mg kg—1 every 48 hours—by oral gavage of cow lung UFH. The final dosage was injecting 10% formalin in methanol into the jugular vein right after thrombus start. Four hours later, the vessel was checked for thrombosis. Heparin levels in endothelium and tissue as well as plasma anticoagulant activity were assessed. As 3×7.5 When heparin (mg kg-1) was administered, the incidence of thrombosis was notably lower during 48-hour dosing intervals than with a single dose. Endothelial heparin concentration and thrombotic incidence were negatively correlated, while anticoagulant activity was not. Treatment with three doses of 1mg kg-1 every 48 hours resulted in a thrombotic incidence comparable to that of a single dosage. The total thrombotic incidence after 15 doses was comparable to that following s.c. treatment and was lower than that of 3 doses. Oral UFH delivery resulted in increased antithrombotic activity and antithrombotic effects that were comparable to those of s.c. administration. Heparin’s antithrombotic effect on endothelium was linked to it.

Platelet reactivity and activated clotting time predict haemorrhagic site complications in patients with chronic coronary syndromes undergoing percutaneous coronary intervention

Abstract Background/Introduction Same-day discharge has become a standard of care for patients with chronic coronary syndromes (CCS) treated with ad hoc percutaneous coronary interventions (PCI). QuickClot Radial kaolin-based haemostatic device may shorten haemostasis time and reduce the incidence of vascular site complications. Besides unfractionated heparin (UFH) and aspirin (ASA), an ad hoc procedure demands a loading dose of clopidogrel. Dynamic changes in platelets and thrombotic activity may influence the outcomes at vascular sites. Rapid "point-of-care" testing measures the effects of anticoagulation but the optimal threshold during and after PCI still requires further research. Purpose We investigated the effect of a standard dose of UFH and a loading dose of clopidogrel measured with point-of-care devices: Hemochron activated clotting time device (ACT), VerifyNow P2Y12 test on on-site outcomes. Methods We conducted a prospective, observational study of consecutive patients with CCS who qualified for ad hoc PCI. Patients were on chronic ASA therapy, received 100 IU/kg UFH, and a 600 mg loading dose of clopidogrel. ACT was measured before and 10 min, 2 h, and 6 h after the administration of UFH and clopidogrel, respectively, and the VerifyNow P2Y12 test measured after 2 and 6 h. A QuickClot haemostatic pad with gradually released compression for up to 2 h was used in all patients. Ultrasonographic assessment of artery diameter and patency was performed before and 6 h after the procedure. Bleeding (BARC criteria) or local haematoma (EASY scale) were observed regularly until hospital discharge. Results Forty patients were enrolled in the study. The mean±SD age was 68.8±8.8 years, 30 (75%) patients were men, 13 (35%) had diabetes, 38 (95%) hypertension, 16 (40%) previous myocardial infarction, and 15 (37,5%) were active smokers. Patients received a median [interquartile range (IQR)] 8000 [7000-9000] IU of UFH and 600 mg of clopidogrel. All of the radial arteries remained patent during observation; local bleeding (BARC 2) was observed in 11 (27,5%) and haematomas (EASY 1 and 2) in 11 (27,5%) patients. Patients with bleeding had lower platelet activity measured with platelet reactivity units (PRU) after 2 h (122.5± 51 vs 158.7± 43, p= 0.04) and higher ACT (s) (216.9 ±40 vs. 184.6±28 s, p=0.006). An ACT >196 s, measured 2 h after the procedure, predicted the occurrence of bleeding or haematoma (AUC 0.72; 95%CI 0.56-0.85, p=0.008). Conclusion Lower platelet activity and higher ACT after PCI were associated with higher risk of haemorrhagic site complications. "Point-of-care" measures post PCI in CCS patients may be clinically applicable.

PB1529 Anticoagulation Protocol of Therapeutic Unfractionated Heparin Administration for Pregnant Women with Mechanical Prosthetic Heart Valves

PB1529 Anticoagulation Protocol of Therapeutic Unfractionated Heparin Administration for Pregnant Women with Mechanical Prosthetic Heart Valves

A-390 Implementation of the New GEM Hemochron 100 Point-of-care Coagulation System for Heparin Monitoring During Cardiopulmonary Bypass Procedures

Abstract Background The Ohio State University Wexner Medical Center has monitored the administration of unfractionated heparin (UFH) during cardiopulmonary bypass (CPB) procedures with the activated coagulation time test, using the Hemochron Signature Elite (Elite) instrument (Werfen) with the ACT+ cartridge. An assessment was conducted to evaluate the performance of the newest Hemochron model, the GEM Hemochron 100 (Werfen), to upgrade current instruments. Methods Precision and Methods Comparison studies were conducted with nine GEM Hemochron 100 systems. Each GEM Hemochron 100 instrument was analyzed with two levels of directCHECK liquid quality control, five replicates, over four days. The Method Comparison study compared the results from one Elite system's result, against the average result reported from one to three GEM Hemochron 100 systems. This methodology was repeated in multiple groups, using different Elite and GEM Hemochron 100 systems. All tests were performed with the ACT+ assay, which is sensitive to UFH from 1–6 IU/mL. Results Precision: All nine GEM Hemochron 100 instruments yielded: Level 1 CV ≤ 9.5%, and Level 2 CV ≤ 2.5%. Method Comparison: Total datasets 66; range 94–902 seconds; estimated bias at the 300, 420, and 480 second ACT+ clinical decision points were 1.6, 3.2, 4.1 seconds respectively; correlation (r) 0.97; slope 1.01; average CV across GEM Hemochron 100 systems 6.0%. Conclusion The performance of the new GEM Hemochron 100 system demonstrated acceptable agreement compared to the Elite system during CPB, maintaining existing ACT+ procedural target times. Results of system performance were consistent with the manufacturer's package insert, as well as previously published data. Based on the clinical performance, GEM Hemochron 100 systems have been implemented into our surgical suites.

Meta-analysis of the effectiveness of heparin in suppressing physiological myocardial FDG uptake in PET/CT.

The present meta-analysis aims to investigate the effectiveness of heparin administration in suppressing physiological myocardial 18F-fluorodeoxyglucose (FDG) uptake on positron emission tomography (PET)/computed tomography (CT), as its role in this regard has not been well investigated. PRISMA guidelines were used to interrogate the PubMed, Embase, Cochrane library, Web of Knowledge, and www.clinicaltrail.gov databases from the earliest records to March 2023. The final analysis included five randomized controlled trials (RCTs). Meta-analysis was conducted to compare the effectiveness of unfractionated heparin (UFH) administration versus non-UFH administration, and subgroup analysis based on fixed and variable fasting durations was conducted. Effect sizes were pooled using a random-effects model, and the pooled odds ratios (ORs) were calculated. Five eligible RCTs with a total of 910 patients (550 with heparin, 360 without heparin) were included. The forest plot analysis initially indicated no significant difference in the suppression of myocardial FDG uptake between the UFH and non-UFH groups (OR 2.279, 95% CI 0.593 to  8.755, p = 0.23), with a high degree of statistical heterogeneity (I2 = 91.16%). Further subgroup analysis showed that the fixed fasting duration group with UFH administration had statistically significant suppression of myocardial FDG uptake (OR 4.452, 95% CI 1.221 to 16.233, p = 0.024), while the varying fasting duration group did not show a significant effect. According to the findings of our meta-analysis, we suggest that intravenous administration of UFH can be considered as a supplementary approach to suppress myocardial FDG uptake.

Cerebral venous sinus thrombosis associated with SRA-negative heparin-induced thrombocytopenia: case report

BackgroundThere are very few documented reports in literature of cerebral venous sinus thrombosis (CVST) caused by immune-mediated heparin-induced thrombocytopenia (HIT). Further, there are very few reports of false negative serotonin release assays (SRAs) when testing for immune-mediated HIT.Case presentationWe present a case of a 60- year-old male with recent unfractionated heparin administration for venous thromboembolism prophylaxis, an elevated 4T score of 5 and acute CVST in which immune-mediated HIT was suspected. The enzyme-linked immunosorbent assay (ELISA) screening assay was positive for PF4 antibodies and subsequent reflexive SRA testing was negative. However, given the clinical picture, a false-negative SRA was suspected (and eventually confirmed), prompting use of the alternative PF4-dependent p-selectin expression assay (PEA) which was confirmed to be positive. The patient was successfully managed with a bivalirudin infusion and eventually transitioned to apixaban.ConclusionIt is uncommon for immune-mediated HIT with thrombosis to manifest as CVST. Similarly, false-negative SRA is uncommon in immune-mediated HIT. Take-away lessons from our case report include considering HIT in CVST patients with an elevated 4T score and considering the entire clinical picture and degree of suspicion for HIT when interpreting negative HIT testing results. The PEA, in conjunction with the 4Ts score, may be considered as an alternate diagnostic assay for HIT.

Liver toxicity of intravenous heparin treatment in patients with acute ischemic stroke

ObjectiveSerum alanine aminotransferase (ALT), which is an indicator of liver dysfunction, may increase during treatment in patients in the acute phase of stroke. However, the cause of the ALT elevation is unclear, as multiple medications are often being used. We investigated the relationship between medications used in acute ischemic stroke, including cerebral infarction and transient ischemic attack, and ALT elevation. MethodsThe subjects were 230 patients who had been diagnosed with cerebral infarction or TIA and treated at the Stroke Care Unit of Fukuoka University Hospital. We investigated ALT abnormalities that occurred from the start of the treatment over the subsequent 14 days. We also followed patients for an additional seven days to confirm the peak ALT levels. A binomial logistic regression analysis was performed to evaluate the association between medications used during the period and ALT elevation. ResultsThe incidence of ALT abnormality was 23.9% (55/230). ALT elevation was mostly mild and peaked within 21 days of treatment initiation in 93.2% of the patients, excluding indeterminate patients. A binary logistic regression analysis showed that unfractionated heparin (odds ratio [OR] 2.759, 95% confidence interval [CI] 1.328–5.729, p = 0.007) was extracted as a cause of ALT elevation. In a receiver operating characteristic (ROC) analysis for the administration period of unfractionated heparin, the cut-off value (area under the ROC curve) for ALT elevation was 6 days (0.575). Significant factors contributing to ALT elevation caused by unfractionated heparin included an unfractionated heparin administration period of ≥ 6 days (OR 2.951, 95% CI 1.244–7.000, p = 0.014) and edaravone combination (OR 2.594, 95% CI 1.159–5.808, p = 0.021). ConclusionIn the acute phase of stroke, we believe that unfractionated heparin discontinuation is not necessary when hepatotoxicity of unfractionated heparin is suspected. However, physicians should be aware of the risk of liver toxicity when unfractionated heparin is administered for more than six days or when edaravone is used in combination.

Smoking and Activated Clotting Time during coronary angiography and angioplasty: protocol for the ACT-Tobacco trial

BackgroundDuring percutaneous transluminal coronary angioplasty (PTCA), activated clotting time (ACT) measurements are recommended to attest a correct anticoagulation level and, if needed, to administer further unfractionated heparin (UFH) to obtain a therapeutic ACT value. Our clinical routine led us to observe that smokers had lower ACT values after standardized UFH administration during PTCA. Procoagulant status in smokers is well documented. ObjectivesTo determine whether tobacco negatively affects UFH anticoagulation during PTCA when evaluated by ACT. MethodsThe ACT-TOBACCO trial is a single-center, noninterventional, prospective study. The primary end point is the comparison of ACT values after standardized UFH administration between active smokers and nonsmokers (active smoker group vs nonsmoker group) requiring coronary angiography followed by PTCA. The main secondary end points include ACT comparison after the first and second standardized UFH administration according to the patient’s smoking status (active, ex-, or nonsmoker) and the clinical presentation of ischemic cardiomyopathy: stable (silent ischemia or stable angina) or unstable (unstable angina or acute coronary syndrome without or with ST-segment elevation). ConclusionsTo the best of our knowledge, ACT values during PTCA between smokers and nonsmokers have not previously been compared. As current PTCA procedures increase in complexity and duration, the understanding of procoagulant risk factors such as smoking and the need for reliable anticoagulation monitoring becomes essential to balance hemorrhagic risk against thrombotic risk.

Comparison between unfractionated heparin (UFH) and fondaparinux on platelets and D-dimer level in COVID-19 patients with hypercoagulation

Introduction: This study aimed to compare the clinical effects between UFH and fondaparinux in COVID-19 patients with hypercoagulation. Material and methods: This was a prospective cohort study. Samples were taken consecutively from hospitalized COVID-19 patients with hypercoagulation who received UFH or fondaparinux based on the standardized guidelines. A total of 71 patients met the inclusion criteria. Patients were evaluated for platelet and D-dimer values before and after administration of UFH or fondaparinux. Results: Although there was no difference in D-dimer reduction between the two groups (p = 0.44), fondaparinux showed a greater reduction, 26% against 22% for UFH. While on platelets, there was a significant difference (p = 0.04) between fondaparinux and UFH. Fondaparinux showed a reduced thrombocytopenia impact, as seen by an increase in pre- and post-therapy platelets of up to 50%, compared to 16% in UFH. In regard to the incidence of Heparin-Induced Thrombocytopenia (HIT), there was no significant difference between post-UFH therapy and post-fondaparinux therapy (p = 0.361). Conclusion: Fondaparinux did not reduce platelet levels as much as UFH, but there was no difference between the fondaparinux group compared to the UFH group in the effect of decreasing D-dimer levels and the sign of HIT.

Heparin Does Not Regulate Circulating Human PCSK9 (Proprotein Convertase Subtilisin-Kexin Type 9) in a General Population-Brief Report.

PCSK9 (proprotein convertase subtilisin-kexin type 9) chaperones the hepatic LDLR (low-density lipoprotein receptor) for lysosomal degradation, elevating serum LDL (low-density lipoprotein) cholesterol and promoting atherosclerotic heart disease. Though the major effect on the hepatic LDLR comes from secreted PCSK9, the details of PCSK9 reuptake into the hepatocyte remain unclear. In both tissue culture and animal models, HSPGs (heparan sulfate proteoglycans) on hepatocytes act as co-receptors to promote PCSK9 reuptake. We hypothesized that if this PCSK9:HSPG interaction is important in humans, disrupting it with unfractionated heparin (UFH) would acutely displace PCSK9 from the liver and increase plasma PCSK9. We obtained remnant plasma samples from 160 subjects undergoing cardiac catheterization before and after administration of intravenous UFH. PCSK9 levels were determined using a commercial enzyme-linked immunosorbent assay. Median plasma PCSK9 was 113 ng/mL prior to UFH and 119 ng/mL afterward. This difference was not significant (P=0.83 [95% CI, -6.23 to 6.31 ng/mL]). Equivalence testing provided 95% confidence that UFH would not raise plasma PCSK9 by > 4.7%. Among all subgroups, only subjects with the lowest baseline PCSK9 concentrations exhibited a response to UFH (8.8% increase, adj. P=0.044). A modest correlation was observed between baseline plasma PCSK9 and the change in plasma PCSK9 due to UFH (RS=-0.3634; P<0.0001). Administration of UFH does not result in a clinically meaningful effect on circulating PCSK9 among an unselected population of humans. The results cast doubt on the clinical utility of disrupting the PCSK9:HSPG interaction as a general therapeutic strategy for PCSK9 inhibition. However, the observations suggest that in selected populations, disrupting the PCSK9:HSPG interaction could still affect PCSK9 reuptake and offer a therapeutic benefit.

Subcutaneous Enoxaparin for Systemic Anticoagulation of COVID-19 Patients During Extracorporeal Life Support.

BackgroundExtracorporeal membrane oxygenation, with an inherent requirement for anticoagulation to avoid circuit thrombosis, is a key element in the treatment of respiratory failure associated with COVID-19. Anticoagulation remains challenging, the standard of care being intravenous continuous administration of unfractionated heparin. Yet regimens vary. Some intensive care units in our center have successfully used enoxaparin subcutaneously in recent years and throughout the pandemic.MethodsWe retrospectively analyzed adult COVID-19 patients with respiratory failure who had been systemically anticoagulated using either enoxaparin or unfractionated heparin. The choice of anticoagulant therapy was based on the standard of the intensive care unit. Defined thromboembolic and hemorrhagic events were analyzed as study endpoints.ResultsOf 98 patients, 62 had received enoxaparin and 36 unfractionated heparin. All hazard ratios for the thromboembolic (3.43; 95% CI: 1.08–10.87; p = 0.04), hemorrhagic (2.58; 95% CI: 1.03–6.48; p = 0.04), and composite (2.86; 95% CI: 1.41–5.92; p = 0.007) endpoints favored enoxaparin, whose efficient administration was verified by peak levels of anti-factor Xa (median: 0.45 IU ml−1; IQR: 0.38; 0.56). Activated partial thromboplastin time as well as thrombin time differed significantly (both p<0.001) between groups mirroring the effect of unfractionated heparin.ConclusionsThis study demonstrates the successful use of subcutaneous enoxaparin for systemic anticoagulation in patients with COVID-19 during extracorporeal membrane oxygenation. Our findings are to be confirmed by future prospective, randomized, controlled trials.

Delayed-Type Heparin Allergy: Intravenous Tolerance Despite Inflammatory Skin Reaction After Subcutaneous Injection

Heparin allergy most frequently manifests as delayed-type hypersensitivity (DTH) causing an itchy inflammatory skin reaction at the site of subcutaneous injection. An important differential diagnosis is circumscribed skin necrosis due to heparin-induced thrombocytopenia. An inflammatory skin reaction to subcutaneously injected heparin generally entails the quest for alternative anticoagulation; concerns may particularly arise in an emergency situation requiring intravenous heparin administration. All heparin DTH cases seen in our department over the last 17 years underwent standardized allergy diagnostics including challenge testing, that is, subcutaneous injection of fondaparinux and intravenous administration of unfractionated heparin (UFH). Of a total of 50 patients with confirmed heparin allergy, DTH was found in 48 (96.0%), and immediate-type, presumably IgE-mediated hypersensitivity was diagnosed in only 2 (4.0%). In the 48 DTH cases, intradermal testing revealed broad cross-reactivity between UFH and low-molecular-weight heparins (LMWH) including nadroparin, dalteparin, and enoxaparin. Cross-reactivity with (or concomitant sensitization to) fondaparinux was seen in only 3 (6.3%) cases. Intravenous administration of UFH was tolerated by all 45 patients challenged, despite DTH to UFH and LMWH as demonstrated by intradermal testing. If an inflammatory skin reaction at the site of subcutaneously injected heparin is observed or reported without any evidence of skin necrosis or thrombocytopenia, intravenous administration of UFH seems to be sufficiently safe and may be considered without allergy testing if urgently indicated in an emergency situation. Fondaparinux is the most suitable alternative for subcutaneous application.

Parenteral anticoagulants in the treatment of acute coronary syndrome: what modern clinical guidelines say

Parenteral administration of high (therapeutic) doses of anticoagulants is a mandatory component of the initial treatment of acute coronary syndrome (ACS) unless contraindicated. In ACS, intravenous administration of unfractionated heparin, the use of low molecular weight heparin enoxaparin, selective antagonist of activated X clotting factor fondaparinux sodium and direct thrombin antagonist bivalirudin are possible. The review presents current approaches to the choice of drugs and the specifics of parenteral anticoagulant use depending on ACS variant (with or without persistent ST-segment elevations on ECG), approaches to myocardial revascularization, previous use of oral anticoagulants, renal function, risk of major bleeding, presented in current versions of European Society of Cardiology and Russian Society of Cardiology guidelines, approved by the Russian Ministry of Health. It is shown that, according to the results of randomized controlled trials and expert opinion, for most ACS treatment scenarios (streptokinase thrombolytic therapy or no reperfusion therapy in ACS with persistent ST elevation on ECG, ACS without persistent ST elevation) the optimal approach is parenteral administration of sodium fondaparinux. Exceptions include primary percutaneous coronary intervention and very early invasive treatment of ACS without persistent ST-segment elevation, but initial treatment with sodium fondaparinux does not prevent these approaches. Additional advantages of sodium fondaparinux are the absence of the need to monitor the coagulation system, a fixed dose, as well as the possibility of use in patients with significant thrombocytopenia. If short-term use of parenteral anticoagulant is expected (in early invasive treatment of ACS), there are contraindications or limitations to the use of sodium fondaparinux and sodium enoxaparin, the means of choice for most cases is intravenous administration of unfractionated heparin.

Timing and Associated Outcomes of Chemical Prophylaxis Against Venous Thromboembolism in the Elderly Trauma Population.

This study aims to assess chemical VTE prophylactic type and timing and associated outcomes within the elderly trauma population. This is a single center study of Trauma Registry data, inclusive years July 1, 2016, to February 28, 2021. The patients were grouped based upon discharge disposition. 7261 elderly trauma patients were included in the analysis. Late administration of VTE prophylaxis was associated with a discharge disposition to hospice. Administration of unfractionated heparin was most associated with in-hospital mortality. Xa inhibitors had the least impact on morbidity and mortality, with most likely associations in discharge to rehab or a skilled nursing facility. LMWH associated with a discharge to a rehab facility. The timing of administration and type of VTE prophylaxis may significantly affect the morbidity and mortality outcomes in elderly trauma.

Aspirin, heparin and ischemia time in microvascular free flap surgery - their influence and an optimal anticoagulation protocol

BackgroundMicrovascular surgery has become a standardized technique for reconstruction of large tissue defects in Head and Neck Reconstructive Surgery. However, the main dreaded complications are thrombosis of blood vessels or major bleeding after surgery. Several different anticoagulation protocols have been established in the last decades to overcome these problems with varying degrees of success. MethodsOver a period of six years, a standardized anticoagulation protocol including acetylsalicylic acid (ASA) and unfractionated heparin (UFH) for direct intraoperative and postoperative administration was established, optimized and compared to a previously used non-standardized protocol. A total of 178 flap surgeries were included in the development and optimization process of the protocol. ResultsASA significantly increased the risk of complications when used for longer than 72 h (OR = 2.52; p = 0.002; 95% CI 1.39–4.59). Administration of UFH reduced flap loss (bolus: OR 0.68; p = 0.47; 95% CI 0.24–1.93; continuous UFH administration: OR = 0.61; p = 0.33; 95% CI 0.22–1.66), however doses greater than 500 IU/ h of UFH as continuous infusion increased the risk of complications. Reduction in ischemia time had no effect on the occurrence of complications. ConclusionAnticoagulation regimes in microvascular surgery can influence the postoperative complication rate. The optimal protocol should consist of a combination of ASA and UFH for the intraoperative and direct postoperative phase. Prolonged administration of ASA as well as doses >500 IU/ h of UFH are to be avoided due to the increased complication rate.

Heparin in the treatment of aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis.

Cerebral vasospasm and the resulting infarction remain the most devastating complications of aneurysmal subarachnoid hemorrhage (aSAH). Limited treatment options are available, with nimodipine as the only approved prophylactic medication. In addition to its anticoagulant properties, heparin also has a pleiotropic and anti-inflammatory effect that could be beneficial in vasospasm. In this study, the authors sought to evaluate the efficacy and safety of heparin in the treatment of aSAH. The PubMed, EBSCOhost, Europe PMC, and Cochrane Central databases were searched to find studies including patients with aSAH who were treated with intravenous unfractionated heparin (UFH) after an aneurysm-securing procedure. Studies that did not include a comparison with UFH or low-molecular-weight heparin in deep vein thrombosis prophylactic doses were excluded. The primary outcome was cerebral vasospasm, and the secondary outcomes were cerebral infarction, clinical deterioration caused by delayed cerebral ischemia, bleeding complications, and thromboembolism complications. Overall, 5 nonrandomized studies were included; 4 studies evaluated the safety and 3 studies evaluated the efficacy of intravenous heparin. From the analysis of 3 studies with a total of 895 patients, administration of intravenous UFH for > 48 hours was related to a significantly lower rate of cerebral infarction (OR 0.44, 95% CI 0.25-0.79). No significant association was found with other efficacy outcomes. Regarding cognitive outcome, one study found a significant improvement in Montreal Cognitive Assessment scores; however, the functional outcome as indicated by the modified Rankin Scale score was not improved by heparin administration. From the analysis of 4 studies with 1099 patients, no significant increases in bleeding and other complications were found. Administration of intravenous UFH for more than 48 hours reduced the rate of cerebral infarction with a good safety profile. This result supports the ongoing clinical trial.

Complement activation during cardiopulmonary bypass and association with clinical outcomes.

In this prospective, single‐centre observational study of 30 patients undergoing cardiopulmonary bypass (CPB), the effect of unfractionated heparin (UFH), CPB surgery and protamine sulphate on complement and on post‐operative blood loss were assessed. Although C3 and C4 levels decreased significantly immediately following the administration of UFH, C3a, C5a, Bb fragment and SC5b‐9 remained unchanged. During CPB, C3 and C4 continued to fall whilst both alternative and classical pathways activation markers, Bb, C3a, C5a and SC5b‐9 increased significantly. Protamine sulphate had no effect on classical pathway components or activation markers but decreased alternative pathway activation marker Bb. Over the 12–24 h post‐surgery, both classical and alternative pathway activation markers returned to baseline, whilst C3 and C4 levels increased significantly but not to baseline values. Total drain volume 24 h after the surgery showed a moderate inverse correlation with post‐protamine C3 (r = −0.46, p = 0.01) and C4 (r = −0.57, p = 0.0009) levels, whilst a moderate positive correlation was observed with post‐protamine C3a (r = 0.46, p = 0.009), C5a (r = 0.37, p = 0.04) and SC5b‐9 (r = 0.56, p = 0.001) levels but not with Bb fragment (r = 0.25, p = 0.17). Thus, inhibition of complement activation may be a therapeutic intervention to reduce post‐operative blood in patients undergoing CPB.