Real-world risk assessment of combined cilostazol-rosuvastatin: a retrospective cohort study using Korean electronic health records

Background Cilostazol and rosuvastatin are frequently co-prescribed for cardiovascular disease management, particularly in Asian populations. Despite widespread clinical use, comprehensive real-world safety data for this drug combination remain limited. Objective To evaluate the 1-year safety profile of cilostazol-rosuvastatin combination therapy compared with that of cilostazol monotherapy in a real-world Korean population using electronic health records. Methods This retrospective cohort study utilised the Observational Medical Outcomes Partnership (OMOP) Common Data Model from Gachon University Gil Hospital (2004–2025). Patients on stable rosuvastatin therapy (≥90 days) who had cilostazol added to their treatment (n = 262) were compared to cilostazol monotherapy patients (n = 6,323). Primary outcomes were incidence of atherosclerotic cardiovascular disease (ASCVD), bleeding, and myopathy at 90 and 365 days. Secondary outcomes included changes in liver enzyme levels and platelet count. Fisher’s exact and Welch’s t-tests were used for statistical analyses. Results The combination group had higher baseline comorbidities compared with the monotherapy group, including chronic kidney disease (45.8% vs. 32.1%), diabetes mellitus (55.0% vs. 29.2%), and concurrent antithrombotic therapy (61.1% vs. 27.9%). At the 365-day follow-up, no primary safety events occurred in the combination group (0/113) versus ASCVD 2/2,307 (0.1%), bleeding 3/2,307 (0.1%), and myopathy 1/2,307 (0.0%) in the monotherapy group (p = 1.00). Laboratory parameters remained stable: AST/ALT change +14.0 vs. +5.7 U/L (p = 0.71), platelet change −8.1 vs. +18.0 ×10 9 /L (p = 0.14). Conclusion Cilostazol-rosuvastatin combination therapy demonstrated a favourable real-world safety profile despite a higher baseline risk. These findings support the safety of this combination in routine clinical practice.