Lipid levels and risk of recurrent venous thrombosis: results from the MEGA follow‐up study

Unlabelled Box Essentials • The role of lipid levels in the risk of recurrent venous thrombosis is unclear. • Lipids were assessed in patients with a first venous thrombosis (n = 2106) followed for 6.9 years. • Lipids were not associated with recurrence, overall or in patients with unprovoked first events. • Testing lipid levels is not useful to identify patients at an increased risk of recurrence. Acknowledgements We express our gratitude to all individuals who participated in the MEGA study and to the staff involved in the execution of the study. This work was supported by the Netherlands Heart Foundation (grants NHS98.113, NHS2010B167, NHS208B086 and NHS2011T012), the Dutch Cancer Foundation (RUL 99/1992) and the Netherlands Organization for Scientific Research (grant 912‐03‐033|2003). The Netherlands Heart Foundation, the Dutch Cancer Foundation and the Netherlands Organization for Scientific Research played no role in the design and conduct of the study, the collection, management, analysis and interpretation of the data, the preparation, review and approval of the manuscript, or the decision to submit the manuscript for publication. Netherlands Heart Foundation NHS98.113 NHS2010B167 NHS208B086 NHS2011T012 Dutch Cancer Foundation RUL 99/1992 Netherlands Organization for Scientific Research 912‐03‐033|2003 Summary: Background Knowledge of risk factors for recurrent venous thrombosis may guide decisions on duration of anticoagulation. The association between lipid levels and first venous thrombosis has been studied extensively. However, data on the role of lipids in the risk of recurrence are scarce. Objective To assess the association between lipid levels and recurrent venous thrombosis. Patients/Methods Patients with a first venous thrombosis from the MEGA study were included. Follow‐up started at the date of end of anticoagulant treatment. Percentile categories of total/low‐density lipoprotein/high‐density lipoprotein cholesterol, triglycerides and apolipoproteins B and A1 were established (< 10th, 10th–25th, 25th–75th [reference], 75th–90th, > 90th percentile). Lipids were measured at least 3 months after discontinuing anticoagulation. Results Of 2106 patients followed for a median of 6.9 years, 326 developed recurrence (incidence rate, 2.7/100 patient‐years; 95% confidence interval [CI], 2.5–3.1). With hazard ratios ranging from 0.88 (95% CI, 0.55–1.42) to 1.33 (95% CI, 0.86–2.04) in the highest percentile category vs. the reference, we found no association across percentile categories between recurrence and lipid levels in age‐ and sex‐adjusted models, nor after further adjustments for body mass index, diabetes, estrogen and statin use, and duration of anticoagulation. Subgroup analyses stratified by unprovoked or provoked first events, location (deep vein thrombosis or pulmonary embolism) and sex also did not reveal an association with any of the lipid levels studied. Conclusions Testing lipid levels did not identify patients at an increased risk of recurrent venous thrombosis in this study, including those with unprovoked first events, and these should not influence decisions on duration of anticoagulation.