-
Analytical Sciences : the International... Sep 2023This paper describes a sensitive method for determining protamine and heparin by utilizing a glucose oxidase enzymatic reaction. Polycationic protamine significantly...
This paper describes a sensitive method for determining protamine and heparin by utilizing a glucose oxidase enzymatic reaction. Polycationic protamine significantly promoted the enzymatic reaction rate with [Fe(CN)], so that the increase could be used to determine protamine. The promotion effect was stoichiometrically decreased by the addition of polyanionic heparin through the polyion complex formation with protamine, so that the enzymatic reaction also allowed for the determination of heparin. We thus applied the proposed method to blood plasma containing heparin and found that heparin did not stoichiometrically form a polyion complex with protamine, likely due to strong interactions between heparin and some components of the plasma. The proposed method allowed for the detection of free protamine (and/or weakly binding protamine with heparin) existing in the condition that protamine did not neutralize all of the heparin in the plasma. The method also permitted for the estimation of heparin concentrations using calibration curves. Thus, the proposed method would help reduce the risks of protamine overdose in heparin neutralization and would be a helpful tool in clinical practices that use heparin and protamine.
Topics: Heparin; Protamines; Glucose Oxidase
PubMed: 37243969
DOI: 10.1007/s44211-023-00373-x -
Journal of Thrombosis and Haemostasis :... Oct 2018Essentials Heparin-protamine balance (HPB) modulates bleeding after neonatal cardiopulmonary bypass (CPB). HPB was examined in 44 neonates undergoing CPB. Post-operative... (Observational Study)
Observational Study
UNLABELLED
Essentials Heparin-protamine balance (HPB) modulates bleeding after neonatal cardiopulmonary bypass (CPB). HPB was examined in 44 neonates undergoing CPB. Post-operative bleeding occurred in 36% and heparin rebound in 73%. Thrombin-initiated fibrin clot kinetic assay and partial thromboplastin time best assessed HPB.
SUMMARY
Background Neonates undergoing cardiopulmonary bypass (CPB) are at risk of excessive bleeding. Blood is anticoagulated with heparin during CPB. Heparin activity is reversed with protamine at the end of CPB. Paradoxically, protamine also inhibits blood coagulation when it is dosed in excess of heparin. Objectives To evaluate heparin-protamine balance in neonates undergoing CPB by using research and clinical assays, and to determine its association with postoperative bleeding. Patients/Methods Neonates undergoing CPB in the first 30 days of life were studied. Blood samples were obtained during and after surgery. Heparin-protamine balance was assessed with calibrated automated thrombography, thrombin-initiated fibrin clot kinetic assay (TFCK), activated partial thromboplastin time (APTT), anti-FXa activity, and thromboelastometry. Excessive postoperative bleeding was determined by measurement of chest tube output or the development of cardiac tamponade. Results and Conclusions Of 44 neonates enrolled, 16 (36%) had excessive postoperative bleeding. The TFCK value was increased. By heparin in neonatal blood samples, but was only minimally altered by excess protamine. Therefore, it reliably measured heparin in samples containing a wide range of heparin and protamine concentrations. The APTT most closely correlated with TFCK results, whereas anti-FXa and thromboelastometry assays were less correlative. The TFCK and APTT assay also consistently detected postoperative heparin rebound, providing an important continued role for these long-established coagulation tests in the management of postoperative bleeding in neonates requiring cardiac surgical repair. None of the coagulation tests predicted the neonates who experienced postoperative bleeding, reflecting the multifactorial causes of bleeding in this population.
Topics: Anticoagulants; Blood Coagulation; Blood Coagulation Tests; Cardiopulmonary Bypass; Drug Monitoring; Female; Heparin; Heparin Antagonists; Humans; Infant, Newborn; Male; Postoperative Hemorrhage; Predictive Value of Tests; Prospective Studies; Protamines; Risk Factors; Treatment Outcome
PubMed: 30016577
DOI: 10.1111/jth.14245 -
BMC Cardiovascular Disorders May 2022Compared to simple percutaneous coronary intervention (PCI), complex PCI is associated with higher bleeding and thrombotic risk. No previous study has evaluated the use...
BACKGROUND
Compared to simple percutaneous coronary intervention (PCI), complex PCI is associated with higher bleeding and thrombotic risk. No previous study has evaluated the use of protamine after PCI with contemporary technologies. This study aimed to evaluate the safety and efficacy of manual compression with and without protamine after transfemoral complex PCI.
METHODS
We retrospectively analyzed 160 patients (protamine group, n = 92; non-protamine group, n = 68) who underwent complex PCI via the femoral artery. The primary outcome was a composite of in-hospital death, myocardial infarction, stent thrombosis, stroke/systemic embolism, bleeding requiring blood transfusion, and vascular access complications.
RESULTS
The primary outcome was significantly lower in the protamine group than in the non-protamine group (4.3% vs. 17.6%; p = 0.006). This was driven mainly by the lower incidences of hematoma in the protamine group (3.3% vs. 13.2%, p = 0.020). Furthermore, the protamine group had a significantly shorter hospital stay than the non-protamine group (4.8 ± 3.7 days vs. 8.4 ± 8.3 days, p = 0.001). While > 90% of the patients had acute coronary syndrome, there were no incidences of myocardial infarction or stent thrombosis in either group.
CONCLUSIONS
Among patients who underwent complex PCI via transfemoral access, immediate protamine administration was associated with a significantly lower rate of vascular access complications, especially hematoma, and shorter hospital stay than no protamine administration.
Topics: Anticoagulants; Hematoma; Hemorrhage; Heparin; Hospital Mortality; Humans; Myocardial Infarction; Percutaneous Coronary Intervention; Protamines; Retrospective Studies; Thrombosis; Treatment Outcome
PubMed: 35538419
DOI: 10.1186/s12872-022-02650-5 -
Reviews in Cardiovascular Medicine Jan 2022Perioperative anticoagulation management with uninterrupted or minimally interrupted anticoagulation during atrial fibrillation (AF) ablation is thought to be critical... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Perioperative anticoagulation management with uninterrupted or minimally interrupted anticoagulation during atrial fibrillation (AF) ablation is thought to be critical to minimize thromboembolic complications. Protamine is often administered to neutralize the effects of heparin and expedite vascular hemostasis post-procedure.
OBJECTIVE
We performed a systematic review and meta-analysis to determine the effectiveness of protamine to expedite vascular hemostasis and ambulation in patients undergoing AF ablation.
METHODS
Electronic searches on PubMed, The Cochrane Library, EMBASE, EBSCO, Web of Science, and CINAHL databases from the inception through August 7, 2021, were performed. The primary outcomes included-time to hemostasis (minutes) and time to ambulation (minutes). The secondary outcomes included - any vascular complications (excluding minor hematoma), minor hematoma, or cerebrovascular accidents (CVA).
RESULTS
A total of 5 eligible studies (3 retrospective cohort studies and two randomized trials) consisting of 1012 patients (515 patients received protamine group and 497 patients did not receive protamine group) were included in the meta-analysis. There was a significant reduction in time to ambulation [weighted mean difference (WMD) -176.6 minutes, 95% Confidence interval (CI) -266.9 to -86.3; < 0.01] and time to hemostasis (WMD -13.72 minutes, 95% CI -22 to -5.4, < 0.01) in the protamine group compared to the contrary. At a follow-up up to 3 months, there was no statistical difference between the two groups with regards to vascular complications (2.9% vs. 7.4%; Risk ratio (RR) 0.46 95% CI 0.17 to 1.24; = 0.12), minor hematoma (2.1% vs. 5.8%; RR 0.43, 95% CI 0.16 to 1.2; = 0.11) or CVA (0 vs. 0.3%; RR 0.62, 95% CI 0.08 to 4.98; = 0.65).
CONCLUSION
Protamine administration was associated with reduced time to ambulation (176 minutes reduction) and time to hemostasis (13 minutes reduction) without an increase in any adverse events.
Topics: Anticoagulants; Atrial Fibrillation; Catheter Ablation; Humans; Protamines; Retrospective Studies; Treatment Outcome
PubMed: 35092226
DOI: 10.31083/j.rcm2301034 -
Andrology Sep 2016Existing literature suggests evidence that protamine deficiency is related to DNA damage and male fertility. In this meta-analysis, we analyzed the relationship between... (Meta-Analysis)
Meta-Analysis Review
Existing literature suggests evidence that protamine deficiency is related to DNA damage and male fertility. In this meta-analysis, we analyzed the relationship between the ratio of protamine-1 and protamine-2 with male fertility and the association of protamine deficiency with sperm DNA damage. Quality of available cohort studies was evaluated using the Newcastle-Ottawa Scale checklist. Summary effect estimates with 95% confidence intervals (CI) were derived using a random effects model. The effect of the protamine ratio on male fertility was analyzed in nine studies demonstrating a significantly higher value of the protamine ratio in subfertile men (n = 633) when compared with controls (n = 453, SMD = 0.46, 95% CI 0.25-0.66, Z = 4.42, p < 0.00001). Both protamine mRNA (SMD = 0.45, 95% CI 0.11-0.79, Z = 2.63, p = 0.009) and protein ratio (SMD = 0.46, 95% CI 0.25-0.68, Z = 4.22, p < 0.0001) showed significantly increased values in subfertile patients. The association between protamine deficiency and DNA damage was analyzed in 12 studies (n = 845) exhibiting a combined overall correlation coefficient (COR) of 0.53 (95% CI 0.28-0.71, Z = 3.87, p < 0.001). Protamine deficiency measured by CMA3 staining was significantly associated with sperm DNA damage (COR = 0.71, 95% CI 0.48-0.85, Z = 4.87, p < 0.001), whereas the P1/P2 ratio was not (COR = 0.17, 95% CI -0.16 to 0.46, Z = 0.99, p = 0.33). It is concluded that the protamine ratio represents a suitable biomarker for the assessment of sperm quality and protamine deficiency is closely related with sperm DNA damage.
Topics: DNA Damage; DNA Fragmentation; Humans; Infertility, Male; Male; Protamines; Spermatozoa
PubMed: 27231200
DOI: 10.1111/andr.12216 -
Annals of Cardiac Anaesthesia 2021Protamine is routinely administered to neutralize the anticlotting effects of heparin, traditionally at a dose of 1 mg for every 100 IU of heparin-a 1:1 ratio protamine... (Observational Study)
Observational Study
CONTEXT
Protamine is routinely administered to neutralize the anticlotting effects of heparin, traditionally at a dose of 1 mg for every 100 IU of heparin-a 1:1 ratio protamine sparing effects-but this is based more on experience and practice than literature evidence. The use of Hemostasis Management System (HMS) allows an individualized heparin and protamine titration. This usually results in a decreased protamine dose, thus limiting its side effects, including paradox anticoagulation.
AIMS
This study aims to assess how the use of HMS allows to reduction of protamine administration while restoring the basal activated clotting time (ACT) at the end of cardiac surgery.
SETTINGS AND DESIGN
A retrospective observational study in a tertiary care university hospital.
SUBJECTS AND METHODS
We analyzed data from 42 consecutive patients undergoing cardiopulmonary bypass (CPB) for cardiac surgery. For all patients HMS tests were performed before and after CPB, to determine how much heparin was needed to reach target ACT, and how much protamine was needed to reverse it.
RESULTS
At the end of cardiopulmonary bypass, 2.2 ± 0.5 mg/kg of protamine was sufficient to reverse heparin effects. The protamine-to-heparin ratio was 0.56:1 over heparin total dose (a 44% reduction) and 0.84:1 over heparin initial dose (a 16% reduction).
CONCLUSION
A lower dose of protamine was sufficient to revert heparin effects after cardiopulmonary bypass. While larger studies are needed to confirm these findings and detect differences in clinically relevant outcomes, the administration of a lower protamine dose is endorsed by current guidelines and may help to avoid the detrimental effects of protamine overdose, including paradox bleeding.
Topics: Anticoagulants; Cardiac Surgical Procedures; Cardiopulmonary Bypass; Heparin; Heparin Antagonists; Humans; Protamines; Whole Blood Coagulation Time
PubMed: 33884973
DOI: 10.4103/aca.ACA_26_19 -
European Journal of Vascular and... Sep 2016The aim was to evaluate the safety and efficacy of heparin reversal with protamine after completion of carotid endarterectomy (CEA), summarising the available data from... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
The aim was to evaluate the safety and efficacy of heparin reversal with protamine after completion of carotid endarterectomy (CEA), summarising the available data from both randomised and non-randomised studies.
METHODS
The study was a meta-analysis. Pooled odds ratios (ORs) with 95% confidence intervals (95% CIs) were calculated for the outcomes of stroke and wound haematoma among patients receiving or not receiving protamine after CEA. Meta-regression analysis was performed to examine whether the documented differences were modified by potentially meaningful patient related or procedure related predictors, namely publication year, general anesthesia used, number of patients treated, mean age (years), males, neurological symptoms, use of patch, and use of shunt.
RESULTS
Seven studies were included in the meta-analysis reporting on 3,817 patients receiving protamine after CEA and 6,070 patients not receiving protamine for heparin reversal. Only one study was randomised. A statistically significant reduction in wound haematoma requiring re-operation was recorded after heparin reversal with protamine in patients undergoing CEA (OR, 0.42, 95% CI, 0.22-0.80, p = .008). In contrast, no significant difference was observed in stroke rates between groups of patients that received and did not receive protamine (OR, 0.71, 95% CI, 0.49-1.03, p = .07). Meta-regression analysis did not reveal any significant effect mediated by the modifiers examined.
CONCLUSION
On the basis of the available data, heparin reversal with protamine seems to reduce the risk of wound haematoma, without increasing the risk of procedural stroke. However, taking into account the limitations of the analysis, further studies are needed to increase the level of evidence provided by the current meta-analysis.
Topics: Endarterectomy, Carotid; Heparin Antagonists; Humans; Postoperative Hemorrhage; Protamines; Stroke
PubMed: 27389942
DOI: 10.1016/j.ejvs.2016.05.033 -
The Annals of Pharmacotherapy Feb 2021The recent shortage of protamine prompted an investigation of alternatives for reversal of unfractionated heparin. Heparin is an anticoagulant utilized in the hospital... (Review)
Review
The recent shortage of protamine prompted an investigation of alternatives for reversal of unfractionated heparin. Heparin is an anticoagulant utilized in the hospital setting. Available options for anticoagulation include direct oral anticoagulants, vitamin K antagonists, thrombin inhibitors, low-molecular-weight heparins, and heparin. Protamine is the approved reversal agent for heparin with few alternatives under investigation. Although andexanet was designed as an antidote for apixaban and rivaroxaban, in vitro studies show that in a dose-dependent technique, andexanet had near full reversal of heparin, reversed anti-factor Xa activity, and neutralized anticoagulant effects of activated partial thromboplastin time and thrombin time induced by heparin.
Topics: Anticoagulants; Blood Coagulation; Blood Coagulation Tests; Factor Xa; Hemorrhage; Heparin; Heparin Antagonists; Humans; Protamines; Recombinant Proteins
PubMed: 32667214
DOI: 10.1177/1060028020943160 -
PLoS Medicine Jun 2021The dose of protamine required following cardiopulmonary bypass (CPB) is often determined by the dose of heparin required pre-CPB, expressed as a fixed ratio. Dosing... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
The dose of protamine required following cardiopulmonary bypass (CPB) is often determined by the dose of heparin required pre-CPB, expressed as a fixed ratio. Dosing based on mathematical models of heparin clearance is postulated to improve protamine dosing precision and coagulation. We hypothesised that protamine dosing based on a 2-compartment model would improve thromboelastography (TEG) parameters and reduce the dose of protamine administered, relative to a fixed ratio.
METHODS AND FINDINGS
We undertook a 2-stage, adaptive randomised controlled trial, allocating 228 participants to receive protamine dosed according to a mathematical model of heparin clearance or a fixed ratio of 1 mg of protamine for every 100 IU of heparin required to establish anticoagulation pre-CPB. A planned, blinded interim analysis was undertaken after the recruitment of 50% of the study cohort. Following this, the randomisation ratio was adapted from 1:1 to 1:1.33 to increase recruitment to the superior arm while maintaining study power. At the conclusion of trial recruitment, we had randomised 121 patients to the intervention arm and 107 patients to the control arm. The primary endpoint was kaolin TEG r-time measured 3 minutes after protamine administration at the end of CPB. Secondary endpoints included ratio of kaolin TEG r-time pre-CPB to the same metric following protamine administration, requirement for allogeneic red cell transfusion, intercostal catheter drainage at 4 hours postoperatively, and the requirement for reoperation due to bleeding. The trial was listed on a clinical trial registry (ClinicalTrials.gov Identifier: NCT03532594). Participants were recruited between April 2018 and August 2019. Those in the intervention/model group had a shorter mean kaolin r-time (6.58 [SD 2.50] vs. 8.08 [SD 3.98] minutes; p = 0.0016) post-CPB. The post-protamine thromboelastogram of the model group was closer to pre-CPB parameters (median pre-CPB to post-protamine kaolin r-time ratio 0.96 [IQR 0.78-1.14] vs. 0.75 [IQR 0.57-0.99]; p < 0.001). We found no evidence of a difference in median mediastinal/pleural drainage at 4 hours postoperatively (140 [IQR 75-245] vs. 135 [IQR 94-222] mL; p = 0.85) or requirement (as a binary outcome) for packed red blood cell transfusion at 24 hours postoperatively (19 [15.8%] vs. 14 [13.1%] p = 0.69). Those in the model group had a lower median protamine dose (180 [IQR 160-210] vs. 280 [IQR 250-300] mg; p < 0.001). Important limitations of this study include an unblinded design and lack of generalisability to certain populations deliberately excluded from the study (specifically children, patients with a total body weight >120 kg, and patients requiring therapeutic hypothermia to <28°C).
CONCLUSIONS
Using a mathematical model to guide protamine dosing in patients following CPB improved TEG r-time and reduced the dose administered relative to a fixed ratio. No differences were detected in postoperative mediastinal/pleural drainage or red blood cell transfusion requirement in our cohort of low-risk patients.
TRIAL REGISTRATION
ClinicalTrials.gov Unique identifier NCT03532594.
Topics: Aged; Anticoagulants; Blood Coagulation; Cardiac Surgical Procedures; Cardiopulmonary Bypass; Drug Dosage Calculations; Drug Monitoring; England; Female; Heparin; Heparin Antagonists; Humans; Male; Middle Aged; Models, Biological; Protamines; Thrombelastography; Time Factors; Treatment Outcome; Victoria
PubMed: 34097705
DOI: 10.1371/journal.pmed.1003658 -
Oncoimmunology 2022Nanoparticles of different sizes formulated with unmodified RNA and Protamine differentially engage Toll-like Receptors (TLRs) and activate innate immune responses ....
Nanoparticles of different sizes formulated with unmodified RNA and Protamine differentially engage Toll-like Receptors (TLRs) and activate innate immune responses . Here, we report that similar differential immunostimulation that depends on the nanoparticle sizes is induced in wild type as well as in humanized mice. In addition, we found that the schedule of injections strongly affects the magnitude of the immune response. Immunostimulating 130 nm nanoparticles composed of RNA and Protamine can promote lung metastasis clearance but provides no control of subcutaneous tumors in a CT26 tumor model. We further enhanced the therapeutic capacity of Protamine-RNA nanoparticles by incorporating chemotherapeutic base analogues in the RNA; we coined these (icRNAs). Protamine-icRNA nanoparticles were successful at controlling established subcutaneous CT26 and B16 tumors as well as orthotopic glioblastoma. These data indicate that icRNAs are promising cancer therapies, which warrants their further validation for use in the clinic.
Topics: Animals; Mice; RNA; Antineoplastic Agents; Nanoparticles; Glioblastoma; Protamines
PubMed: 36419823
DOI: 10.1080/2162402X.2022.2147665