Thromboembolic Risk among Patients on Dual Antiplatelet Therapy with or without Heparin Thromboprophylaxis

Abstract

Background

Venous thromboembolism (VTE) is a common complication among hospitalized patients. Low-molecular-weight heparin (LMWH) is recommended for thromboprophylaxis, but its benefits in non-surgical patients, particularly those receiving dual antiplatelet therapy (DAPT), remain unclear. Currently, evidence on the risks and benefits of LMWH thromboprophylaxis in patients on DAPT is lacking.

Methods

This retrospective cohort study included patients hospitalized in the cardiology departments of two hospitals of LMU University Munich between May 2015 and April 2025. Patients receiving DAPT, defined as treatment with aspirin and a P2Y12 inhibitor, were analyzed. The study population was divided into two groups: those who received LMWH prophylaxis and those who did not. The primary endpoint was the incidence of VTE during hospitalization, confirmed through imaging techniques. Secondary endpoints included the need for erythrocyte transfusion.

Results

A total of 8,619 patients receiving DAPT were included, of which 2,378 were receiving LMWH prophylaxis. The incidence of VTE was very low and did not differ between the LMWH and non-LMWH groups (0.04% versus 0%, p = 0.28). Subgroup analysis revealed higher bleeding rates as mirrored by more erythrocyte transfusions in the LMWH group (9.4 versus 5.1%, p = 0.004).

Conclusion

In patients receiving DAPT, LMWH thromboprophylaxis was associated with a comparably low incidence of VTE but a higher rate of erythrocyte transfusions in subgroup analysis.

Keywords

venous thromboembolism - dual antiplatelet therapy - heparin - low molecular weight

Ethical Approval Statement

The study was approved by the local ethics committee of the Ludwig-Maximilians University Munich (IRB number: 18–001).

Data Availability Statement

The datasets generated and/or analyzed during the current study are not publicly available due to ethical committee regulations but might be available from the corresponding author on reasonable request and provided that ethical committee approves data sharing.

Authors' Contribution

J.G. contributed to data interpretation, drafting of manuscript, statistical analysis, final approval. R.K. contributed to data interpretation, revision of manuscript. J.F., A.K., L.W., T.M.S., K.S., J.H., and S.M. contributed to substantial contribution to data acquisition. C.S. contributed to data acquisition, statistical analysis, drafting of manuscript, final approval.

Publication History

Received: 26 January 2025

Accepted: 18 May 2025

Accepted Manuscript online:
19 May 2025

Article published online:
29 May 2025

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