Evaluation of Prothrombin Time and Activated Partial Thromboplastin Time in Antithrombotic-Treated Cardiac Patients: A Cross-Sectional Study from Sana’a City, Yemen

Background: Antithrombotic therapy is a cornerstone of managing cardiac diseases, necessitating routine monitoring of coagulation parameters like Prothrombin Time (PT) and Activated Partial Thromboplastin Time (APTT). Data on the coagulation profiles of treated patients in resource limited settings like Yemen are scarce. Objective: This study aimed to evaluate PT and APTT in antithrombotic-treated cardiovascular patients and assess their variation across different cardiac diagnoses and therapy regimens in Sana’a, Yemen. Methods: A cross-sectional study was conducted on 200 cardiovascular patients on antithrombotic therapy at selected hospitals in Sana’a City between January and March 2024. Demographic, clinical, and therapeutic data were collected. Coagulation parameters (PT, INR, APTT) were measured and compared across diagnostic groups and treatment types using Kruskal–Wallis and Mann–Whitney U -tests, with Bonferroni correction for multiple comparisons. Results: The study group was predominantly male (69.0%), aged 51– 80 years (57.0%). Coagulation parameters varied significantly across cardiac diagnoses (p < 0.01 for PT, INR, APTT). Patients with Mitral Valve Replacement (MVR) had the highest median PT (36.45s) and INR (2.75). Post-hoc analysis confirmed MVR patients had significantly elevated parameters compared to other groups (e.g. PT 19.01s higher than Segment Elevation Myocardial Infarction (STEMI), p=0.003). Rheumatic Heart Disease (RHD) patients showed intermediate PT elevation. No significant differences were found between STEMI and Non-ST-segment Elevation - Acute Coronary Syndrome (NSTE-ACS) subtypes. Antithrombotic type significantly influenced results: warfarin patients had the highest median PT (20.00s), INR (1.53), and APTT (40.00s) (p< 0.05). Dosage analysis confirmed warfarin’s significant impact compared to aspirin doses. Conclusion: Coagulation profiles in cardiovascular patients vary significantly according to both the underlying cardiac diagnosis and the type of antithrombotic therapy. MVR and RHD patients display notably elevated parameters, while ACS subtypes show similar profiles. These findings underscore the need for diagnosis-specific monitoring strategies and confirm the expected pharmacological effects of different antithrombotic agents in a Yemeni population. Keywords: antithrombotic therapy, coagulation monitoring, prothrombin time, international normalized ratio, cardiovascular diseases, Yemen