CONFERENCE UPDATE: ASH 2023
Updates to the ASH guidelines on VTE: Thrombophilia testing and anticoagulation in COVID-19 patients
Both thrombophilia (acquired or hereditary) and coronavirus disease 2019 (COVID-19) are associated with an increased risk of venous thromboembolism (VTE).1,2 ASH thus developed guidelines that aimed to provide evidence-based recommendations to support decision-making about thrombophilia testing and the use of anticoagulants for COVID-19 patients.3,4 During the ASH Annual Meeting & Exposition 2023, Professor Saskia Middeldorp presented the ASH guidelines for thrombophilia testing which focused on whether testing for thrombophilia and tailoring management based on testing results would improve patient-important outcomes in different scenarios.1 Subsequently, Dr. Deborah Siegal presented the ASH COVID-19 guidelines which focused on anticoagulant dose intensity in hospitalized COVID-19 patients and in those discharged after hospitalization who do not have suspected or confirmed VTE.4
While thrombophilia testing can improve risk stratification of VTE and guide the treatment and prevention of VTE, there is a risk of false negatives (missed diagnosis) and false positives (overdiagnosis), as well as potential physical, psychological, and financial harm to patients.1 For each clinical question, the panel thus compared 2 scenarios: (a) thrombophilia testing and intervention only in individuals found to have thrombophilia and (b) no thrombophilia testing and usual care in all individuals.1 For each recommendation, the panel considered the risk of bleeding vs. recurrent thrombosis, the cost and burden of thrombophilia testing and anticoagulant treatment, as well as patient preference.1 In total 23 recommendations were provided with nearly all recommendations based on very low certainty in the evidence due to modeling assumptions (table 1).3
Recommendation (R) no. |
Population |
Recommendation |
Strength, certainty in evidence |
Patients with symptomatic VTE |
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R1 |
Unprovoked VTE |
Do not test for thrombophilia |
Conditional, very low |
R2 |
VTE provoked by surgery |
Do not test for thrombophilia |
Conditional, very low |
R3 |
VTE provoked by nonsurgical major transient risk factor |
Test for thrombophilia, and indefinite anticoagulant treatment for patients with thrombophilia |
Conditional, very low |
R4 |
VTE provoked by pregnancy or postpartum |
Test for thrombophilia, and indefinite anticoagulant treatment for patients with thrombophilia |
Conditional, very low |
R5 |
VTE associated with use of COC |
Test for thrombophilia, and indefinite anticoagulant treatment for patients with thrombophilia |
Conditional, very low |
R6 |
An unspecified type of VTE (i.e., not specified as provoked or unprovoked VTE) |
Do not test for thrombophilia |
Conditional, very low |
Patients with symptomatic VTE in unusual sites |
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R7 |
CVT |
(a) In settings when anticoagulation would otherwise be discontinued after primary short-term treatment: test for thrombophilia, and indefinite anticoagulant treatment for patients with thrombophilia |
Conditional, very low |
R8 |
CVT |
(b) In settings when anticoagulation would otherwise be continued indefinitely: do not test for thrombophilia |
Conditional, very low |
R9 |
Splanchnic venous thrombosis |
(a) In settings when anticoagulation would otherwise be discontinued after primary short-term treatment: test for thrombophilia, and indefinite anticoagulant treatment for patients with thrombophilia |
Conditional, very low |
R10 |
Splanchnic venous thrombosis |
(b) In settings when anticoagulation would otherwise be continued indefinitely: do not test forthrombophilia |
Conditional, very low |
Asymptomatic individuals with a family history of VTE and/or thrombophilia |
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Individuals with a minor transient risk factor for VTE |
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R11 |
Individuals with a family history of VTE and known thrombophilia |
Strategy #1: Selective testing for the thrombophilia known in the family |
|
Heterozygous FVL or heterozygous PGM |
Do not test for thrombophilia |
Conditional, very low |
|
Protein C, S, or antithrombin deficiency |
Test for the thrombophilia known in the family and use thromboprophylaxis in individuals with thrombophilia |
Conditional, very low |
|
R12 |
Individuals with a family history of VTE and known thrombophilia |
Strategy #2: Doing a thrombophilia panel |
|
Heterozygous FVL or heterozygous PGM |
Do not test for a panel of hereditary thrombophilias (panel) |
Conditional, very low |
|
Protein C, S, or antithrombin deficiency |
Test for all hereditary thrombophilia (panel) and use thromboprophylaxis in individuals with thrombophilia |
Conditional, very low |
|
R13 |
Individuals with a family history of VTE and unknown thrombophilia status |
Do not test for thrombophilia |
Conditional, very low |
R14 |
Individuals with a family history of thrombophilia but no VTE |
|
|
Heterozygous FVL or heterozygous PGM |
Do not test for thrombophilia |
Conditional, very low |
|
Protein C, S, or antithrombin deficiency in first-degree relatives |
Test for the thrombophilia known in the family and use thromboprophylaxis in individuals with thrombophilia |
Conditional, very low |
|
Protein C, S, or antithrombin deficiency in second-degree relatives |
Either test or do not test for the thrombophilia known in the family to guide thromboprophylaxis |
Conditional, very low |
|
Women considering using COC or HRT |
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R15 |
Women from the general population considering COCs |
Do not test for thrombophilia |
Strong, low |
R16 |
Women from the general population considering HRT |
Do not test for thrombophilia |
Conditional, low |
R17 |
Women with a family history of VTE and unknown thrombophilia in the family considering COCs |
Do not test for thrombophilia |
Conditional, very low |
R18 |
Women with a family history of VTE and unknown thrombophilia in the family considering HRT |
Do not test for thrombophilia |
Conditional, very low |
R19 |
Women with a family history of VTE and thrombophilia considering COCs |
Strategy: Selective testing for the thrombophilia known in the family |
|
FVL or PGM |
Do not test for thrombophilia |
Conditional, very low |
|
Protein C, S, or antithrombin deficiency |
Test for thrombophilia and avoid COCs in women with thrombophilia |
Conditional, very low |
|
R20 |
Women with a family history of VTE and thrombophilia considering HRT |
Strategy: Selective testing for the thrombophilia known in the family |
|
|
FVL or PGM |
Do not test for thrombophilia |
Conditional, very low |
|
Protein C, S, or antithrombin deficiency |
Test for thrombophilia and avoid HRT in women with thrombophilia |
Conditional, very low |
Women who are planning pregnancy |
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Antepartum prophylaxis |
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R21 |
Women with a family history of VTE and thrombophilia |
Strategy: Selective testing for the thrombophilia known in the family |
|
|
Known homozygous FVL, combination of FVL and PGM, or antithrombin deficiency |
Test for the thrombophilia known in the family and use antepartum thromboprophylaxis in women with thrombophilia |
Conditional, very low |
|
Known protein C or protein S deficiency in the family |
Either test or do not test for the thrombophilia known in the family to guide antepartum thromboprophylaxis |
Conditional, very low |
Postpartum prophylaxis |
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R22 |
Women with a family history of VTE and thrombophilia |
Strategy: Selective testing for the thrombophilia known in the family |
|
Known homozygous FVL, combination of FVL and PGM, or antithrombin, protein C, or protein S deficiency |
Test for the thrombophilia known in the family and use postpartum thromboprophylaxis in women with thrombophilia |
Conditional, very low |
|
Known combination of FVL and PGM, or antithrombin deficiency in second-degree relatives |
Test for the thrombophilia known in the family and use postpartum thromboprophylaxis in women with thrombophilia |
Conditional, very low |
|
Known protein C or protein S deficiency in the family |
Either test or do not test for the thrombophilia known in the family to guide postpartum thromboprophylaxis |
Conditional, very low |
|
Patients with cancer |
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R23 |
Ambulatory patients with cancer who are classified to be at low or intermediate risk for VTE, who have a family history of VTE in first-degree relatives |
Strategy: Doing a thrombophilia panel test for all hereditary thrombophilia (panel) and use thromboprophylaxis in individuals with thrombophilia |
Conditional, very low |
Table 1: Summary of recommendations for thrombophilia testing3
COC: Combined oral contraceptive; CVT: Cerebral venous thrombosis; FVL: Factor V Leiden; HRT: Hormone replacement therapy; PGM: Prothrombin 20210A gene mutation; R: Recommendation; VTE: Venous thromboembolism
Similarly, recognizing and minimizing the risk of harm from anticoagulants is a critical component for the treatment of VTE in COVID-19 patients.4 The updated ASH focused on providing recommendations on adjusting the intensity of anticoagulants for acutely or critically ill hospitalized COVID-19 patients, and for patients who were discharged after hospitalization for COVID-19 who do not have suspected or confirmed VTE (table 2).2,4 The guideline also included an initial phase and a living phase, during which monthly updated searches for baseline risk estimates, prognostic factors, and the effect of anticoagulation strategies are performed, allowing guideline recommendations to be continuously revisited if new evidence meets pre-specified criteria.4
Recommendation |
Strength, certainty in evidence |
R1: The ASH guideline panel suggests using prophylactic-intensity over intermediate-intensity or therapeutic-intensity anticoagulation for patients with COVID-19-related critical illness who do not have suspected or confirmed VTE |
Conditional, very low
|
R2a: The ASH guideline panel suggests using prophylactic-intensity over intermediate-intensity anticoagulation for patients with COVID-19-related acute illness who do not have suspected or confirmed VTE R2b; The ASH guideline panel suggests using therapeutic-intensity over prophylactic-intensity anticoagulation for patients with COVID-19-related acute illness who do not have suspected or confirmed VTE |
Conditional, very low
|
R3: The ASH guideline panel suggests against using post-discharge prophylactic-intensity anticoagulation in patients with COVID-19 discharged from the hospital who do not have suspected or confirmed VTE |
Conditional, very low |
Table 2: Summary of recommendations on the use of anticoagulation in COVID-19 patients2,4
ASH: American Society of Hematology; COVID-19: Coronavirus disease 2019; R: Recommendation; VTE: Venous thromboembolism