Prevalence and Outcomes of Antiphospholipid Syndrome after Unprovoked Venous Thromboembolism: a multi-centre real-world data analysis

Abhinav Mathur; Catrin  Cox; Shabnam  Banerjee; Marilyn  Rees; Lara  Roberts; Karen A.  Breen; Claire  Lentaigne; Raza Alikhan; Andrew J.  Doyle; Mohammed Mahbub Khan

doi:10.1016/j.jtha.2026.04.036

Prevalence and Outcomes of Antiphospholipid Syndrome after Unprovoked Venous Thromboembolism: a multi-centre real-world data analysis

Abhinav Mathur^* (Corresponding Author)
, Catrin Cox
, Shabnam Banerjee
, Marilyn Rees
, Lara Roberts
, Karen A. Breen
, Claire Lentaigne
, Raza Alikhan
, Andrew J. Doyle
, Mohammed Mahbub Khan

^*Corresponding author for this work

Medical Sciences

Guy's and St Thomas' NHS Foundation Trust
University Hospitals Plymouth NHS Trust
Cardiff University
King's College Hospital NHS Foundation Trust
University of Plymouth
Cardiff & Vale University Health Board
NHS Grampian

Research output: Contribution to journal › Article › peer-review

Abstract

Background
Guidance for antiphospholipid antibody (aPL) testing after unprovoked venous thromboembolism (VTE) is inconsistent. Real-world data on the prevalence and outcomes of antiphospholipid syndrome (APS) in those presenting with unprovoked VTE are limited.
Objectives
To determine APS prevalence after unprovoked VTE, compare outcomes from universal versus selective aPL testing, and assess thrombosis recurrence in APS patients within a multi-centre UK cohort.
Methods
This retrospective analysis included 897 patients with unprovoked VTE from five UK centres. One centre used universal (n=533) and four used selective (n=364) aPL testing. The primary outcome was APS prevalence. Secondary outcomes included thrombosis-free survival by testing strategy and by anticoagulant (direct oral anticoagulant [DOAC] vs. vitamin K antagonist [VKA]) in APS patients.
Results
The overall APS prevalence was 11.7% and was higher in the universal testing compared to the selective cohort (15.8% vs. 5.8%). Baseline clinical features were poor predictors of APS. Among 105 APS patients (median follow-up 4.2 years), the annual thrombotic recurrence rate was 2.1 per 100 person-years. A non-significant trend towards higher recurrence was observed over time for DOACs vs. VKAs (3.8 vs. 1.3 events/100 person-years, p = 0.16). No thrombosis-free survival difference was found between testing strategies (p = 0.71).
Conclusions
The prevalence of APS following unprovoked VTE is notable, and selective testing identified fewer APS cases in practice. Identifying aPL antibodies in patients with unprovoked VTE may inform discussions regarding anticoagulation duration and choice, although optimal testing strategies require further prospective evaluation.

Original language	English
Journal	Journal of Thrombosis and Haemostasis
Early online date	12 May 2026
DOIs	https://doi.org/10.1016/j.jtha.2026.04.036
Publication status	E-pub ahead of print - 12 May 2026

Bibliographical note

Open Access via the Elsevier agreement

Author contributions
Contributed to the study design: AM, CC, AJD, MMK. Contributed to the data analysis: AM, CC, AJD, MMK. All authors contributed to data collection, data interpretation, critically revised the manuscript, and provided final approval of the version to be published. The Plymouth study was conducted independently; collaborators from Plymouth (SB, CL) shared their data as part of this project. All authors agree to be accountable for all aspects of the work.

Keywords

venous thrombosis
antiphospholipid syndrome
anticoagulation
epidemiology
thrombophilia

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Cite this

Mathur, A., Cox, C., Banerjee, S., Rees, M., Roberts, L., Breen, K. A., Lentaigne, C., Alikhan, R., Doyle, A. J., & Khan, M. M. (2026). Prevalence and Outcomes of Antiphospholipid Syndrome after Unprovoked Venous Thromboembolism: a multi-centre real-world data analysis. Journal of Thrombosis and Haemostasis. Advance online publication. https://doi.org/10.1016/j.jtha.2026.04.036

@article{8a7357fec3bb410185aafdd477e2ff0b,

title = "Prevalence and Outcomes of Antiphospholipid Syndrome after Unprovoked Venous Thromboembolism: a multi-centre real-world data analysis",

abstract = "Background Guidance for antiphospholipid antibody (aPL) testing after unprovoked venous thromboembolism (VTE) is inconsistent. Real-world data on the prevalence and outcomes of antiphospholipid syndrome (APS) in those presenting with unprovoked VTE are limited. Objectives To determine APS prevalence after unprovoked VTE, compare outcomes from universal versus selective aPL testing, and assess thrombosis recurrence in APS patients within a multi-centre UK cohort. Methods This retrospective analysis included 897 patients with unprovoked VTE from five UK centres. One centre used universal (n=533) and four used selective (n=364) aPL testing. The primary outcome was APS prevalence. Secondary outcomes included thrombosis-free survival by testing strategy and by anticoagulant (direct oral anticoagulant [DOAC] vs. vitamin K antagonist [VKA]) in APS patients. Results The overall APS prevalence was 11.7\% and was higher in the universal testing compared to the selective cohort (15.8\% vs. 5.8\%). Baseline clinical features were poor predictors of APS. Among 105 APS patients (median follow-up 4.2 years), the annual thrombotic recurrence rate was 2.1 per 100 person-years. A non-significant trend towards higher recurrence was observed over time for DOACs vs. VKAs (3.8 vs. 1.3 events/100 person-years, p = 0.16). No thrombosis-free survival difference was found between testing strategies (p = 0.71). Conclusions The prevalence of APS following unprovoked VTE is notable, and selective testing identified fewer APS cases in practice. Identifying aPL antibodies in patients with unprovoked VTE may inform discussions regarding anticoagulation duration and choice, although optimal testing strategies require further prospective evaluation.",

keywords = "venous thrombosis, antiphospholipid syndrome, anticoagulation, epidemiology, thrombophilia",

author = "Abhinav Mathur and Catrin Cox and Shabnam Banerjee and Marilyn Rees and Lara Roberts and Breen, \{Karen A.\} and Claire Lentaigne and Raza Alikhan and Doyle, \{Andrew J.\} and Khan, \{Mohammed Mahbub\}",

note = "Open Access via the Elsevier agreement Author contributions Contributed to the study design: AM, CC, AJD, MMK. Contributed to the data analysis: AM, CC, AJD, MMK. All authors contributed to data collection, data interpretation, critically revised the manuscript, and provided final approval of the version to be published. The Plymouth study was conducted independently; collaborators from Plymouth (SB, CL) shared their data as part of this project. All authors agree to be accountable for all aspects of the work.",

year = "2026",

month = may,

day = "12",

doi = "10.1016/j.jtha.2026.04.036",

language = "English",

journal = "Journal of Thrombosis and Haemostasis",

issn = "1538-7933",

publisher = "Elsevier BV",

}

TY - JOUR

T1 - Prevalence and Outcomes of Antiphospholipid Syndrome after Unprovoked Venous Thromboembolism

T2 - a multi-centre real-world data analysis

AU - Mathur, Abhinav

AU - Cox, Catrin

AU - Banerjee, Shabnam

AU - Rees, Marilyn

AU - Roberts, Lara

AU - Breen, Karen A.

AU - Lentaigne, Claire

AU - Alikhan, Raza

AU - Doyle, Andrew J.

AU - Khan, Mohammed Mahbub

N1 - Open Access via the Elsevier agreement Author contributions Contributed to the study design: AM, CC, AJD, MMK. Contributed to the data analysis: AM, CC, AJD, MMK. All authors contributed to data collection, data interpretation, critically revised the manuscript, and provided final approval of the version to be published. The Plymouth study was conducted independently; collaborators from Plymouth (SB, CL) shared their data as part of this project. All authors agree to be accountable for all aspects of the work.

PY - 2026/5/12

Y1 - 2026/5/12

N2 - Background Guidance for antiphospholipid antibody (aPL) testing after unprovoked venous thromboembolism (VTE) is inconsistent. Real-world data on the prevalence and outcomes of antiphospholipid syndrome (APS) in those presenting with unprovoked VTE are limited. Objectives To determine APS prevalence after unprovoked VTE, compare outcomes from universal versus selective aPL testing, and assess thrombosis recurrence in APS patients within a multi-centre UK cohort. Methods This retrospective analysis included 897 patients with unprovoked VTE from five UK centres. One centre used universal (n=533) and four used selective (n=364) aPL testing. The primary outcome was APS prevalence. Secondary outcomes included thrombosis-free survival by testing strategy and by anticoagulant (direct oral anticoagulant [DOAC] vs. vitamin K antagonist [VKA]) in APS patients. Results The overall APS prevalence was 11.7% and was higher in the universal testing compared to the selective cohort (15.8% vs. 5.8%). Baseline clinical features were poor predictors of APS. Among 105 APS patients (median follow-up 4.2 years), the annual thrombotic recurrence rate was 2.1 per 100 person-years. A non-significant trend towards higher recurrence was observed over time for DOACs vs. VKAs (3.8 vs. 1.3 events/100 person-years, p = 0.16). No thrombosis-free survival difference was found between testing strategies (p = 0.71). Conclusions The prevalence of APS following unprovoked VTE is notable, and selective testing identified fewer APS cases in practice. Identifying aPL antibodies in patients with unprovoked VTE may inform discussions regarding anticoagulation duration and choice, although optimal testing strategies require further prospective evaluation.

AB - Background Guidance for antiphospholipid antibody (aPL) testing after unprovoked venous thromboembolism (VTE) is inconsistent. Real-world data on the prevalence and outcomes of antiphospholipid syndrome (APS) in those presenting with unprovoked VTE are limited. Objectives To determine APS prevalence after unprovoked VTE, compare outcomes from universal versus selective aPL testing, and assess thrombosis recurrence in APS patients within a multi-centre UK cohort. Methods This retrospective analysis included 897 patients with unprovoked VTE from five UK centres. One centre used universal (n=533) and four used selective (n=364) aPL testing. The primary outcome was APS prevalence. Secondary outcomes included thrombosis-free survival by testing strategy and by anticoagulant (direct oral anticoagulant [DOAC] vs. vitamin K antagonist [VKA]) in APS patients. Results The overall APS prevalence was 11.7% and was higher in the universal testing compared to the selective cohort (15.8% vs. 5.8%). Baseline clinical features were poor predictors of APS. Among 105 APS patients (median follow-up 4.2 years), the annual thrombotic recurrence rate was 2.1 per 100 person-years. A non-significant trend towards higher recurrence was observed over time for DOACs vs. VKAs (3.8 vs. 1.3 events/100 person-years, p = 0.16). No thrombosis-free survival difference was found between testing strategies (p = 0.71). Conclusions The prevalence of APS following unprovoked VTE is notable, and selective testing identified fewer APS cases in practice. Identifying aPL antibodies in patients with unprovoked VTE may inform discussions regarding anticoagulation duration and choice, although optimal testing strategies require further prospective evaluation.

KW - venous thrombosis

KW - antiphospholipid syndrome

KW - anticoagulation

KW - epidemiology

KW - thrombophilia

U2 - 10.1016/j.jtha.2026.04.036

DO - 10.1016/j.jtha.2026.04.036

M3 - Article

SN - 1538-7933

JO - Journal of Thrombosis and Haemostasis

JF - Journal of Thrombosis and Haemostasis

ER -

Prevalence and Outcomes of Antiphospholipid Syndrome after Unprovoked Venous Thromboembolism: a multi-centre real-world data analysis

Abstract

Bibliographical note

Keywords

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