PO54 | CANCER-ASSOCIATED THROMBOSIS IN ASPIRIN-TREATED PATIENTS AFTER ARTERIAL THROMBOSIS: THE COMPASS-ARTECAT-ASA PROSPECTIVE COHORT STUDY

G. Gerotziafas^1|3|4|5, S. Allakhverdieva⁶, P. Henrique Fernandes Do Carmo Las Casa¹, P. Van Dreden^1|2, J. Fareed³, N. Lomakin⁶ , I. Zotova⁶, L. Buryachkovskaya⁷ | ¹Sorbonne University, INSERM UMR_S_938, CRSA, Research Department "Cancer, Vessels, Biology and Therapeutics" (CaVITE), Research Group "Cancer-Angiogenesis-Thrombosis and Haemostasis," Thrombosis Center, University Institute of Cancerology (UIC), Saint Antoine University Hospital Assistance Publique Hôpitaux de Paris (AP-HP), Paris, France; ²Clinical Research, Diagnostica Stago, Gennevilliers, France; ³Center of Translational Research and Education, Department of Pathology and Laboratory Medicine, Loyola University Stritch School of Medicine, Maywood, Chicago, USA; ⁴Thrombosis Center, Department of Obstetrics, Gynecology and Perinatal Medicine, The I. M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia; ⁵VAS-European Independent Foundation in Angiology/Vascular Medicine Milan, Italy; ⁶Federal State Budgetary Educational Institution of Further Professional Education "Russian Medical Academy of Continuous Professional Education" of the Ministry of Healthcare of the Russian Federation, Moscow, Russia; ⁷Federal State Budgetary Institution «National Medical Research Centre of Cardiology Named After Academician E. I. Chazov» of the Ministry of Health of the Russian Federation, Moscow, Russia

Introduction. Aspirin is a cornerstone of secondary prevention for arterial thrombosis. However, the influence of cancer on recurrent arterial thromboembolism (ATE), venous thromboembolism (VTE), and mortality in patients with ATE treated with aspirin remains poorly defined.

Aim. The prospective cohort study COMPASS-ARTeCAT-ASA assessed the impact of cancer on ATE recurrence, VTE incidence, and all-cause mortality in patients receiving aspirin monotherapy after an arterial thrombotic event. Specifically, we compared outcomes among patients with active cancer diagnosed before ATE, cancer diagnosed after ATE, and patients with ATE without cancer and evaluated the real-world effectiveness of aspirin in these high-risk populations.

Materials and Methods. We analyzed 2,133 consecutive patients on aspirin 75–100 mg after an index ATE. Patients were stratified into three groups: cancer preceding ATE (Group 1, n=198), cancer following ATE (Group 2, n=29), and no cancer (Group 3, n=1,906). Median follow-up 3.5 years. Primary endpoints: clinically confirmed recurrent ATE, symptomatic VTE (DVT/PE with imaging), and all-cause mortality. Continuous variables are presented as medians (IQR) and compared with Kruskal–Wallis or Mann–Whitney U tests. Categorical data are treated as counts (percentages) and compared with chi-square or two-proportion z-tests. Bonferroni-corrected p<0.0167.

Results. ATE recurrence was higher in Group 1 (8.1%) and Group 2 (6.9%) than in Group 3 (2.4%), with a significant difference between Group 1 and Group 3 (p<0.001). VTE incidence was markedly increased in cancer patients (Group 1: 4.5%; Group 2: 10.3%) compared with Group 3 (0.9%) (p<0.001 for both comparisons). All-cause mortality was significantly higher in Group 1 (12.1%) than in Group 3 (3.4%) (p<0.001). No significant differences were observed between Groups 1 and 2.

Conclusions. In patients receiving aspirin for secondary prevention of arterial thrombosis, cancer—especially when diagnosed before the arterial event—is associated with substantially higher risks of recurrent ATE, VTE, and death. Aspirin monotherapy appears insufficient to counteract cancer-associated thrombotic risk. These findings support systematic VTE risk assessment and pharmacological thromboprophylaxis in high-risk patients, development of cancer-associated arterial thrombosis risk models, and investigation of more effective strategies to prevent arterial thrombosis recurrence in active cancer.