Association of pre-existing antithrombotic therapy with clinical outcomes in patients with acute dengue infection.

BACKGROUND

Dengue infection frequently causes thrombocytopenia and bleeding complications. Patients with cardiovascular disease who receive antiplatelet or anticoagulant therapy represent a clinically challenging population during acute dengue infection. Data regarding clinical outcomes and platelet recovery in these patients remain limited.

METHODS

This observational study included a single-center retrospective cardiovascular dengue cohort and an exploratory platelet-monitoring cohort. In the retrospective cohort, patients were classified according to pre-existing antithrombotic therapy (ATT) at dengue diagnosis: no antithrombotic therapy (No ATT), single antiplatelet therapy (SAPT), dual antiplatelet therapy (DAPT), or oral anticoagulant therapy (OAC). Major bleeding was assessed within 7 and 30 days after dengue diagnosis. In the exploratory platelet-monitoring cohort, serial platelet count and platelet function were assessed during dengue illness.

RESULTS

The retrospective cohort included 1,693 patients (No ATT, n = 1,493; SAPT, n = 163; DAPT, n = 22; OAC, n = 15). ATT users were older and had a greater burden of cardiovascular comorbidities and more frequent severe dengue manifestations. The observed 7-day major bleeding rates in the No ATT, SAPT, DAPT, and OAC groups were 0.34%, 0.61%, 4.55%, and 6.67%, respectively (P = 0.011), with corresponding 30-day rates of 1.15%, 1.84%, 9.09%, and 13.33% (P = 0.002). In the exploratory platelet-monitoring cohort (six non-antiplatelet users and two aspirin users), aspirin users had a longer platelet count nadir-to-recovery time than non-antiplatelet users [median (IQR), 7.5 (6.0-9.0) vs 4.0 (3.75-4.25) days; P = 0.04] and a longer interval from the lowest platelet function value to recovery [median (IQR), 9.5 (8.0-11.0) vs 4.0 (3.75-4.25) days; P = 0.04].

CONCLUSIONS

Pre-existing ATT users had a greater comorbidity burden and more severe dengue manifestations. SAPT users showed similar observed short-term major bleeding rates to patients without ATT. Exploratory monitoring suggested delayed platelet count and function recovery among aspirin users.