September 2025: New In Coagulation
by Donna Castellone • September 03, 2025
Our Monthly complilation of the latest studies, guidelines and discussions in coagulation.
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APOE4 May Raise Brain Bleed Risk in Apixaban Users With AF
A study (n=2000, mean age 71, 55% male) found that carriers of the apolipoprotein E episilon 4 (APOE ε4) allele had a threefold higher risk for ICH when taking apixaban for AF.
Carriers (n-483) were classified as those having one or two alleles and noncarrier (n=1555) had no alleles. Primary outcome was ICH after initiating apixaban therapy, secondary outcomes included intraparenchymal hemorrhage, ischemic stroke, and a composite of ischemic stroke and ICH. HAS-BLED scores were included to look at age, hypertension, stroke and predisposition for bleeding to predict bleeding risk.
ICH developed in 26 participants and was significantly higher in carriers with a threefold increase seen for ICH (hazard ratio [HR] 3.1) and intraparenchymal hemorrhage (HR 3.7). No difference was seen in the other secondary outcomes. This information is important in personalizing pharmacological therapy and identifying high-risk patients.
Limitations in this study include its reliance on EHR and the limited ability to determine the contribution of hypertension and cerebral amyloid angiopathy to lobar and deep hemorrhages. The predominance of European ancestry of the participants may limit the generalization of the findings.
Restarting DOAC Early After a Serious Bleed Risks More Bleeding
OAC are important in preventing strokes in people with AF, butAF but also increase the risk for bleeding. A study from Denmark looked at 10,000 medical records of patients on OAC who presented with an intracranial bleed, GI bleed or nosebleed that required hospitalization. Patients were divided into two groups, those who restarted within 60 days, those later than 60 days. Results showed that those who restarted early were 21% more likely to experience recurrent bleeding without an increased risk for stroke. Restarting early did not show a benefit, but the optimal time to resume OAC was not defined.
New Chapter in Pediatric ITP Treatment: FDA Approves Avatrombopag for Children Aged One and Up
The FDA has approved avatrombopag for age one and older with persistent or chronic immune thrombocytopenia (ITP) who have previously not responded to treatment. ITP affects five in 100,000 children each year with most cases that resolve on their own, however up to 25% of those develop chronic ITP which can impact quality of life and lead to bleeding complications.
Avatrombopag is a thrombopoietin receptor agonist used in adults with chronic liver disease and in adults with chronic ITP who had prior insufficient response to treatment. The Doptelet Sprinkle formulation is configured for children 1-6 years while the tablet is for patients aged 6 and older. The Sprinkle formulation has no food restriction. The AVA-PED-301 study was a phase 3 study that looked at safety and efficacy. Up to 27.8% of patients maintained platelet counts above 50,000/uL for six of the last eight weeks of the study, compared to 0% in the placebo group. Additionally, 81.5% of patients exhibited a strong platelet response without requiring rescue medication, and by Day 8, more than half had achieved platelet counts above 50,000.
Most common side effects were mild and included viral infections, cough, fever and throat pain. There is a small risk of thrombotic events and should not be used to normalize platelet counts.
For coagulation labs, a deep dive into key testing variables
Many variables impact coagulation testing from preanalytic to postanalytic. "CLSI H21: Collection, Transport, and Processing of Blood Specimens for Testing Plasma-Based Coagulation Assays," has released its sixth edition and has important updates to specimen stability. For fibrinogen, D-dimer, and thrombin time, specimen stability time went from four hours in the fifth edition to 24 hours in the sixth. Other examples: Antithrombin was four hours in the fifth edition and is 72 hours in the sixth, and some factor assays went from four to upward of 48 hours. These updated guidelines are based on peer-reviewed literature. UFH stability remains one hour unless collected in CTAD. If the laboratory is using the aPTT to monitor heparin, they need to be aware of the effect of PF4 which neutralizes heparin, this will happen at the four hour mark. When using a chromogenic assay for heparin, it may be extended beyond 1 hour. There was a negligible drop at 75 minutes and a statistically significant drop between 90 minutes and up to two hours.
A frequent deficiency from the CAP checklist for Hematology is to measure the actual platelet count of the PPP used for coagulation tests. This was one of the most cited deficiencies found in 1.6% of labs. The presence of platelets can release microparticles/phosphatidylserine, fibrinogen, factors V and VIII, von Willebrand factor, and platelet factor 4, all of which can neutralize heparin and affect other coagulation tests.
Platelet-poor plasma is defined as less than 10 × 109/L. Platelet activation can result from a freeze-thaw, a cooling of the sample, hemolysis, or use of a pneumatic tube system. Activated platelets release procoagulant phospholipids that can neutralize lupus inhibitors, which can bind to the procoagulant phospholipids, which can lead to a false negative LA test. To demonstrate PPP take a capped tube centrifuged at a speed and time that results in a platelet-poor plasma, <10 × 109/L platelets. The laboratory must establish the speed and time and it will vary depending on the centrifuge in use. The most common centrifugation protocol (and the one cited in H21) is 1,500 g for 15 minutes. Other published protocols have a shorter centrifuge time at a faster speed (4,400 g). The platelet count should be verified with an automated counter. If the plasma is not platelet poor, consider double centrifugation, or a longer centrifugation time.
Stability for platelet function studies is within four hours and must be kept at room temperature. Hand delivery is the preferred way for the specimens to be sent to the lab. It was found that aggregometry and PFA were prolonged in patients on aspirin when samples were sent via pneumatic tube, while TEG clot formation was shorter.
Other issues include hemolysis, icterus and lipemia. Some analyzers have detection capabilities. The photo-optical method is sensitive to HIL in particular to hemolysis and can interfere with results. The electro mechanical is less affected. However, hemolysis may indicate a suboptimal specimen. Manufacturers guidelines have specific limits for interference. Hemolysis that is due to trauma may result in the activation of the coagulation system which could impact results. The most sensitive tests affected are fibrinogen, D-dimer, AT, anti-Xa and lupus.
The ICSH recommends that the aPTT not be performed on samples with hemolysis that occurred in vitro during collection, transport and processing. The PT is not as impacted. However, if the hemolysis occurred in vivo, these can be accepted for coagulation testing. The etiology is important, which can be a challenge for a reference laboratory.
Lipemia can be handled using ultacentrifugation. There can be an impact on vWF and FVIII levels with vWF activity being 31.9% lower, vWF antigen being 12.1% lower and FVIII levels being 23.2% lower, but with minimal impact on the aPTT. These large proteins spin out in ultracentrifugation and should not be used for those tests. The most impacted samples are those who can go from normal to abnormal. Icterus may be handled by dilution protocols to minimize interferences.
The interferences for the D-dimer are free hemoglobin, hyperbilirubinemia, hyper-triglyceridemia, and rheumatoid factor. Some reagents have a RF blocking agent to mitigate the impact. Heterophile antibodies will interfere by binding to the latex beads in the assay and cause agglutination resulting in an overestimation of the D-dimer.
Requirements for factor assays include they be run in a minimum of three dilutions and determined if nonparallelisim is to be reported. The inhibitor interference requires the highest factor activity with the dilution in the factor assay. When a sample is parallel the patient result shows a consistent result on each dilution. Nonspecific inhibitors are seen in lupus anticoagulants, as well as pharmaceutical anticoagulant inhibitors such as heparin, direct oral anticoagulants, or direct thrombin inhibitors. Specific factor inhibitors in acquired hemophilia are nonspecific factor VIII inhibitor. The use of middleware can help to determine inhibitors. Use can result in ease of training, minimization of required technologist time, reduction in staff fatigue, and better consistency and quality, among others.
Simple CT Tweak Detects Stroke Clots 6x Faster, Study Shows
An adjustment to a routine CT angiography in patients with ischemic stroke or TIA could enhance diagnosis. If the area of the trachea is extended 6 cm below it can detect cardiac clots by sixfold. This would result in improving the identification of stoke causes and optimize treatment as seen in the DAYLIGHT study. The study included 465 participants with ischemic stroke or TIA, median age 78, 51% women. There were 226 who had extended CTA versus 239 had a standard CTA. The primary outcome was the detection of cardio-aortic thrombus which was seen in 20 patients in the extended CTA group versus four in the standard CTA, making the extended detection CTA have increased detection of 500%. Up to 95% of these clots were found in the left atrial appendage. The time for the extended detection increased by only 1 minutes therefore it did not significantly delay access to therapy. Radiation exposure was slightly higher but clinically insignificant. Detection of these clots helps to identify the probable origin of the episode improving patient management. If these clots were undetected the stroke would be classified as "undetermined cause". Finding the clots with the extended CTA can accelerate the initiation of anticoagulation. Currently CTA is used in the detection of stroke in 73% of South American centers and 76% of North American centers.
Primary Care Doctors Guide to Prescribing Anticoagulants for AF: Timing, Risks, and Patient Education
The primary care physician is the first professional that identifies cardiac issues including AF. These patients have a fivefold risk for stroke and are often placed on anticoagulants. Up to six million Americans have AF, the risk increases with age and result in 450,000 hospitalizations annually. These patients need to be followed due to the higher incidence of bleeding during the first 3 months of treatment. Prescribing OAC should be based upon the patient's risk for significant bleeding.
Patients should be aware that a clot as small as 2mm can cause a major stroke if it were to break lose from the inside of the top chamber of the heart. This risk is reduced with OAC. They also need to be aware that these DOACs drugs work quickly and wear off fast so daily use is important to prevent a stroke. Warfarin has a more prolonged effect and missing a single dose may not be as consequential.
However, it comes with several drug-drug interactions such as antibiotics as well as dietary restrictions, such as green leafy vegetables since warfarin is a vitamin K antagonist.
On any anticoagulation, minor bleeding events such as gum or nose bleeds should be noted in case of an injury. If bleeding doesn't stop, reversal agents may be required. It is important to know what medication they patients are on, what is the dosethe dose is, and when it was last taken.
JOURNAL CLUB
2025 focused update of the 2020 ISTH guidelines for management of thrombotic thrombocytopenic purpura
X. Long Zheng1, xzheng2@kumc.edu ∙ Zainab Al-Housni ∙ Spero R. Cataland ∙ Rawan Tarawneh ∙ Sara K. Vesely on behalf of the International Society on Thrombosis and Haemostasis
Journal of Thrombosis and Hemostasis
ISTH SSC COMMUNICATIONSArticles in PressJune 17, 2025
Abstract
Background
Over the past few years, new information has emerged in the management of both immune thrombotic thrombocytopenic purpura (iTTP) and congenital (or hereditary) thrombotic thrombocytopenic purpura (cTTP).
Methods
In March 2024, the International Society on Thrombosis and Haemostasis (ISTH) formed a multidisciplinary panel comprising hematologists, intensivists, nephrologists, pathologists, patient representatives, and a methodology team. The panel discussed all treatment questions related to thrombotic thrombocytopenic purpura (TTP) using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) method to appraise evidence and formulate recommendations.Results
For patients with cTTP in remission, a new strong recommendation was issued for the use of recombinant ADAMTS-13 over fresh frozen plasma in the context of moderate certainty evidence. The panel also revised a previous recommendation and suggested using fresh frozen plasma over a watch-and-wait approach for patients with cTTP in remission based on very low certainty evidence should recombinant. The panel reviewed and referenced new publications supporting therapeutic efficacy, potential survival benefit, and cost considerations of adding caplacizumab to therapeutic plasma exchange, corticosteroids, and rituximab, but concluded that no change was warranted to the previous recommendations in the management of iTTP. Good practice statements on the concomitant use of antithrombotic agents were marginally modified.
Conclusions
For patients with iTTP, no change to 2020's recommendations. For patients with cTTP, the panel supports ADAMTS-13 replacement. Where accessible, recombinant ADAMTS-13 provides the most favorable balance of benefits and risks. Otherwise, fresh frozen plasma may still be effective. Shared decision-making should include the benefits, the potential harms, and the burden of care.
Alteplase for Acute Ischemic Stroke at 4.5 to 24 Hours: The HOPE Randomized Clinical Trial
Ying Zhou, PhD; Yaode He, MD; Bruce C. V. Campbell, PhD; et al
JAMA, Published Online: August 7, 2025
Abstract
Importance The safety and efficacy of intravenous thrombolytics beyond 4.5 hours after ischemic stroke onset remain inadequately studied.
Objective To evaluate the safety and efficacy of intravenous alteplase administered 4.5 to 24 hours after stroke onset in patients with salvageable brain tissue, regardless of the presence of large vessel occlusion.
Objective To evaluate the safety and efficacy of intravenous alteplase administered 4.5 to 24 hours after stroke onset in patients with salvageable brain tissue, regardless of the presence of large vessel occlusion.
Design, Setting, and Participants This randomized, open-label, blinded end-point trial was conducted at 26 stroke centers across China. A total of 372 patients with acute ischemic stroke and salvageable brain tissue identified by perfusion imaging were enrolled between June 21, 2021, and June 30, 2024 (final follow-up October 2, 2024). Eligibility criteria included stroke onset (or the midpoint between last known well and symptom recognition if onset was unknown) of 4.5 to 24 hours prior to presentation, and no initial plan for endovascular thrombectomy. Data were analyzed from December 2024 to February 2025.
Interventions Patients were randomly assigned (1:1) using a minimization algorithm to receive intravenous alteplase (0.9 mg/kg; maximum dose, 90 mg; n = 186) or standard medical treatment (n = 186).
Main Outcomes and Measures The primary efficacy outcome was functional independence, defined as a modified Rankin Scale score of 0 to 1 at 90 days. Safety outcomes included symptomatic intracranial hemorrhage within 36 hours and all-cause mortality within 90 days.
Results Among 372 patients who were enrolled (median [IQR] age, 72 [64-80] years; 160 [43%] women), all completed the trial. The primary outcome occurred in 75 of 186 patients (40%) in the alteplase group and 49 of 186 (26%) in the control group (adjusted risk ratio, 1.52 [95% CI, 1.14-2.02];
Conclusions and Relevance In patients with acute ischemic stroke with salvageable brain tissue identified by perfusion imaging who did not initially receive thrombectomy, intravenous alteplase administered 4.5 to 24 hours after onset provided functional benefit, despite an increase in symptomatic intracranial hemorrhage.
Coagulation Disorders in Pregnancy
Juliana Perez Botero
Obstet Gynecol Clin North Am, 2025 Sep;52(3):457-473.
Abstract
Coagulation disorders cause significant morbidity and mortality during pregnancy, and evaluation of hypercoagulability or bleeding are frequently encountered in females of reproductive age. The physiologic changes of the hemostatic system during pregnancy increase the risk of venous thromboembolism and also make laboratory test result interpretation challenging. The risk of thrombosis can be reduced with anticoagulation, but appropriate risk stratification to assure that the benefits outweigh the risks is required. Only patients with severe bleeding disorders typically need preventive management antepartum: however, delivery planning, which has both maternal and fetal implications, is complex and requires coordination between multiple providers.
Immune Thrombotic Thrombocytopenic Purpura: A Review
Allyson M. Pishko, MD, MSCE; Ang Li, MD, MS; Adam Cuker, MD, MS
JAMA Published Online: May 19, 2025. 2025;334;(6):517-529. doi:10.1001/jama.2025.3807
Abstract
Importance Immune thrombotic thrombocytopenic purpura (iTTP) is a life-threatening thrombotic microangiopathy that presents with microangiopathic hemolytic anemia (MAHA) and thrombocytopenia. Worldwide annual incidence of iTTP is 2 cases per million to 6 cases per million.
Observations Immune TTP is caused by an autoantibody to a disintegrin and metallopeptidase with thrombospondin type 1 motif 13 (ADAMTS13), an enzyme that cleaves von Willebrand factor (vWF). With severely low ADAMTS13 activity (<10%), large multimers of vWF accumulate and bind platelets, forming microvasculature thromboses that cause ischemic organ injury (eg, myocardial infarction and stroke). The incidence of iTTP is higher in adults than children (incident rate ratio [IRR], 31.62 per million person-years [95% CI, 14.68-68.10]), females than males (IRR, 3.19 [95% CI, 2.65-3.85]), and Black compared with non-Black individuals (IRR, 7.09 [95% CI, 6.05-8.31]). Common presenting symptoms are neurologic (eg, headache, confusion, or seizures [39%-80%]) and abdominal pain (35%-39%). For patients presenting with MAHA and thrombocytopenia, clinical prediction scores for iTTP using laboratory data, such as platelet count less than 30 × 109/L and creatinine level less than 2.0 mg/dL (176.8 μmol/L), can help guide empirical treatment initiation for iTTP before ADAMTS13 results are available. Prompt initiation of therapy with therapeutic plasma exchange, corticosteroids, and rituximab improves survival with iTTP from almost zero to approximately 93%. Caplacizumab, a synthetic small antibody (nanobody) that blocks platelet binding to vWF, administered concurrently with immunosuppression and therapeutic plasma exchange and continued until ADAMTS13 recovery, reduces the time to normalization of platelet count and decreases the risk of early recurrence (defined as within 30 days of completing therapeutic plasma exchange) compared with placebo (risk difference [RD], −29% [95% CI, −42 to −14%]) but increases bleeding risk (RD, 17% [95% CI, 4%-30%]). After obtaining clinical remission (defined as at least 30 days of sustained normalization of platelet count, decreased serum lactate dehydrogenase level, and absence of new or progressive ischemic organ injury without therapeutic plasma exchange or caplacizumab), 16% of patients have at least 1 relapse of iTTP. Regular monitoring of ADAMTS13 activity in remission and administration of rituximab when ADAMTS13 activity is less than 20% reduces risk of relapse (odds ratio, 0.09 [95% CI, 0.04-0.24]).
Conclusions and Relevance Immune TTP is a rare immune-mediated disorder that presents with thrombocytopenia and MAHA and may cause life-threatening thrombosis. Treatment with therapeutic plasma exchange, corticosteroids, and rituximab is associated with 30-day survival rates of more than 90%. Addition of caplacizumab shortens time to normalization of platelet count and reduces recurrences while receiving the drug but increases bleeding risk. Monitoring ADAMTS13 activity in survivors and initiation of rituximab for those with low ADAMTS13 activity reduces the risk of clinical relapse.
Questions About Strategies and Dosing Levels of PCC for Coagulopathic Bleeding in Cardiac Surgery
Francisco Javier González-Ruiz, MD; Nadia Melisa Queb-Pech, MD; Itzel Elena Portillo-Yañez, MD
JAMA, Published Online: July 28, 2025
To the Editor The recent Factor Replacement in Surgery II (FARES-II) randomized clinical trial compared 4-factor prothrombin complex concentrate (PCC) with frozen plasma in patients undergoing cardiac surgery and experiencing coagulopathic bleeding.1 Although the study presents compelling evidence favoring PCC, several aspects deserve further consideration.
An important limitation lies in the use of point-of-care international normalized ratio (INR) testing as a stand-alone tool to assess coagulation factor deficiency. INR prolongation may result from incomplete heparin reversal, heparin rebound, or hepatic dysfunction rather than actual factor depletion. Moreover, only about 25% of patients undergoing cardiac surgery have true factor deficiency, limiting the generalizability and accuracy of INR-guided protocols.
Postoperative bleeding following cardiac surgery is a multifactorial phenomenon and may involve factors such as thrombocytopenia, platelet dysfunction, fibrinolysis, hypothermia, hemodilution, protamine overdosing, and acquired von Willebrand syndrome. Because patients vary from being stable and undergoing elective procedures to being critically ill individuals undergoing prolonged cardiopulmonary bypass, a one-size-fits-all approach based solely on INR is insufficient. For example, the acquired von Willebrand syndrome commonly observed in severe aortic stenosis, which leads to dual coagulopathy involving both von Willebrand factor and factor VIII, is unlikely to be fully corrected with PCC.
Effective management, therefore, requires tailored strategies. Fibrinogen supplementation for low fibrinogen levels or desmopressin for von Willebrand deficiency may offer more targeted, cost-effective solutions and avoid the fluid burden associated with large-volume plasma transfusions. Moreover, empirical use of PCC could inadvertently delay surgical reexploration in patients with ongoing surgical bleeding, thereby increasing morbidity and mortality.
In this context, viscoelastic assays such as rotational thromboelastometry and thromboelastography offer a more comprehensive, individualized assessment of hemostatic function. These tests have demonstrated benefits in reducing transfusion requirements, shortening hospital stays, and improving survival after cardiac surgery. Consequently, a multimodal, patient-specific approach appears superior to empirical PCC or plasma administration guided solely by INR.
Questions About Strategies and Dosing Levels of PCC for Coagulapathic Bleeding in Cardiac Surgery
Lachlan F. Miles, PhD; Erica M. Wood, PhD; Rinaldo Bellomo, PhD
JAMA ; Published Online: July 28, 2025
A recent trial1 comparing PCC with frozen plasma to treat coagulopathic bleeding in cardiac surgery reported that PCC delivered superior hemostasis and reduced severe or massive bleeding, chest tube drainage, and acute kidney injury. Considerations of possible mechanisms behind these findings is warranted.
First, patients who weighed 60 kg or less were randomized to received either 1500 IU of PCC or 3 units of frozen plasma; those weighing more than 60 kg were randomized to receive either 2000 IU of PCC or 4 units of plasma. Dosing of PCCs was based on factor IX activity. The concentration of factor IX in Canadian plasma (mean, 0.77 [SD, 0.05] IU/mL), and the approximate unit volume (290 mL) are known. Thus, the dose of factor IX administered to patients weighing more than 60 kg (91% of the cohort) in the PCC group (2000 IU) was substantially greater than the mean dose administered to patients in the frozen plasma group (893 IU). Was there a difference in chest drainage between patients who weighed 60 kg or less vs those who weighed more than 60 kg?
Second, once treatment was started, a completed infusion took 7 minutes with PCC vs 26 minutes with frozen plasma. The initiation of PCC could be reduced to less than 5 minutes as opposed to more than 40 minutes in the trial, depending on the proximity of the blood bank to the operating room and the thawing time for frozen plasma.3 Do the authors have information on the relationship between time to trial treatment delivery completion and chest drainage?
Unlike frozen plasma, PCC does not contain fibrinogen. Yet fibrinogen concentrate or cryoprecipitate were given to less than 50% of patients in both groups. Can the authors comment on fibrinogen levels before or after trial drug administration and on the differential chest tube drainage of patients who did and did not receive fibrinogen concentrate or cryoprecipitate?
The volume administered to patients in the frozen plasma group (870-1160 mL based on the average volume of a unit of Canadian plasma)2 was substantially greater than the volume administered to patients in the PCC group (60-80 mL based on a reconstituted volume of 20 mL/vial). This larger volume could increase right atrial pressure and venous congestion and, in turn, increase the risk of bleeding and acute kidney injury. Do the authors have data on central venous pressure following delivery of the trial intervention?
Platelet Transfusion 2025 AABB and ICTMG International Clinical Practice Guidelines
Ryan A. Metcalf, MD1,2; Susan Nahirniak, MD3; Gordon Guyatt, MD4 et al
JAMA Published Online: May 29, 2025
2025;334;(7):606-617. doi:10.1001/jama.2025.7529
Abstract
Importance Platelet transfusion is a frequent procedure with benefits and risks.
Objective To provide recommendations in adult and pediatric populations in whom platelet transfusions are commonly performed.
Evidence Review Grading of Recommendations Assessment Development and Evaluation (GRADE) methodology was applied to findings from 21 randomized trials and 13 observational studies in contexts of limited randomized clinical trial data. Transfusion strategies using fewer (restrictive) vs greater (liberal) amounts of platelets were compared.
Findings Evidence demonstrated that restrictive transfusion strategies probably did not cause increases in mortality or bleeding relative to liberal strategies across predefined clinical populations. Exceedingly low incidence of spinal hematoma was identified in patients with thrombocytopenia undergoing lumbar puncture. Because definitions of restrictive strategies varied across trials, recommendations reflect practical guidance. The following recommendations are strong recommendations with high/moderate–certainty evidence. For hypoproliferative thrombocytopenia in nonbleeding patients receiving chemotherapy or undergoing allogeneic stem cell transplant, platelet transfusion is recommended when platelet count is less than 10 × 103/μL. For consumptive thrombocytopenia in neonates without major bleeding, platelet transfusion is recommended when platelet count is less than 25 × 103/μL. In patients undergoing lumbar puncture, platelet transfusion is recommended when platelet count is less than 20 × 103/μL. In patients with consumptive thrombocytopenia due to Dengue without major bleeding, platelet transfusion is not recommended. The following recommendations are conditional recommendations with low/very low–certainty evidence. For hypoproliferative thrombocytopenia in nonbleeding adults undergoing autologous stem cell transplant or with aplastic anemia, prophylactic platelet transfusion is not recommended. In adults with consumptive thrombocytopenia without major bleeding, platelet transfusion is recommended when platelet count is less than 10 × 103/μL. In adults undergoing central venous catheter placement in compressible anatomic sites, platelet transfusion is recommended when platelet count is less than 10 × 103/μL. In adults undergoing interventional radiology, platelet transfusion is recommended when platelet count is less than 20 × 103/μL for low-risk procedures and less than 50 × 103/μL for high-risk procedures. For adults undergoing major nonneuraxial surgery, platelet transfusion is recommended when platelet count is less than 50 × 103/μL. For patients without thrombocytopenia undergoing cardiovascular surgery in the absence of major hemorrhage, including those receiving cardiopulmonary bypass, platelet transfusion is not recommended. For nonoperative intracranial hemorrhage in adults with platelet count greater than 100 × 103/μL, including those receiving antiplatelet agents, platelet transfusion is not recommended.
Conclusions And Relevance A consistent pattern of evidence supports the implementation of restrictive platelet transfusion strategies. Restrictive strategies reduce risk of adverse reactions, mitigate platelet shortages, and reduce costs. It is good practice to consider overall clinical context and alternative therapies in the decision to perform platelet transfusion.