OC 62.4 - Hormonal contraceptive use after a first venous thromboembolism and the risk of recurrence in premenopausal women

Tuesday, June 25, 2024

15:30 – 15:45 ICT

Room: Ballroom B2

Presenting Author(s)

Judith Verlaan, MSc

PhD Student
Leiden University Medical Center
Leiden, Zuid-Holland, Netherlands

Co-Author(s)

BS

Bernardine Stegeman

PhD
Leiden University Medical Center
Leiden, Zuid-Holland, Netherlands
JT

Jasmijn Timp

PhD
Leiden University Medical Center
Leiden, Zuid-Holland, Netherlands
LS

Luuk Scheres

Post doc
Leiden University Medical Center
Leiden, Zuid-Holland, Netherlands
LF

Linda Flinterman

PhD
Leiden University Medical Center
Leiden, Zuid-Holland, Netherlands
FH

Frans Helmerhorst

MD, PhD
Leiden University Medical Center
Leiden, Zuid-Holland, Netherlands
FR

Frits R Rosendaal

Professor at Leiden University Medical Center and Chairman of the Clinical Epidemiology Department
Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands.
Leiden, Zuid-Holland, Netherlands
Suzanne C. Cannegieter

MD, PhD, prof
Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands.
Leiden, Zuid-Holland, Netherlands
Astrid van Hylckama Vlieg

Associate professor
Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands.
Leiden, Zuid-Holland, Netherlands

Background: Extensive evidence is available on hormonal contraceptive (HC) use and the risk of a first venous thromboembolism (VTE). Despite recommendations to the contrary, some women continue or start combined hormonal contraceptive (CHC) after a first VTE.

Aims: We aimed to evaluate the VTE recurrence risk associated with HC use in premenopausal women.

Methods: Premenopausal women with a first VTE, included in the MEGA study between 1999 and 2004, were followed for a recurrence until 2010. Data on HC use were available through linkage to the Dutch Foundation for Pharmaceutical Statistics. The risk of recurrence was assessed 1) during the initial anticoagulant treatment period and 2) after cessation of anticoagulation. Time-dependent Cox-proportional hazards models were used to estimate hazard ratios (HR) with 95% confidence intervals (95%CI), adjusted for age and BMI at baseline and episodes of thromboprophylaxis use during follow-up. All participants provided informed consent, and the study was approved by the Leiden University Medical Center's medical ethical committee.

Results: 650 women were uniquely linked and followed-up for a total of 3538 person-years (median 6.1 years) during which 57 VTE recurrences occurred. Five occurred (8.8%) during initial anticoagulation treatment, with no clear risk difference for CHC use vs. non-use: HR: 0.8, 95% CI: 0.1-8.2 (Table). After anticoagulation cessation, CHC use was associated with a 2.4-fold higher risk of recurrence (HR: 2.4, 95% CI: 1.2-5.0) compared with non-use (Table). The recurrence risk associated with levonorgestrel-releasing intra-uterine device use was similar with non-use (HR: 1.1, 95% CI: 0.3-3.6) (Figure).

Conclusion(s): CHC use after a first VTE appeared to be safe during anticoagulant use, but substantially increased the risk of a recurrent event in the absence of anticoagulant use. This study adds to the evidence regarding a levonorgestrel-releasing intra-uterine device as a safe alternative.