Early and long-term (one-year) effects of the association of aspirin and oral anticoagulant on thrombi and morbidity after replacement of the mitral valve with the St. Jude medical prosthesis - A clinical and transesophagealechocardiographic study

OBJECTIVES The aim of the study was to test the value of low dose aspirin a ssociated with standard oral anticoagulants (OAC) after mechanical mitral v alve replacement (MMRV) to reduce strands, thrombi and thromboembolic event s. BACKGROUND Strands and thrombi are thought to increase the, risk of embolic events after MMVR, particularly in the immediate postoperative period. METHODS Two hundred twenty-nine patients were prospectively recruited: 109 patients (group A+) were randomly assigned to aspirin (200 mg per day) with OAC and 120 patients (group A-) to OAC alone (international normalized rat io 2.5 to 3.5). All patients were subjected to multiplane transesophageal e chocardiography at nine days and five months and were followed up for one y ear. RESULTS At nine days and five months, there was a high and comparable incid ence of strands in the two groups (group A+: 44%, 58%; group A-: 49%, 63%). However, the incidence of nonobstructive periprosthetic valve thrombi was significantly lower in group A+ at 9 days: 5% versus 13%, p = 0.03. Total thromboembolic events were reduced in group A+ (9% vs. 25%, p = 0.004 ) although there was an increased incidence of gastrointestinal hemorrhage (7% vs. 0%). Overall Valve-related events were similar in mortality was 9% in group A+ and 4% in group A-. both groups. Early thrombi, but not strands ,were associated with higher morbidity, especially thromboembolic events (3 0% vs. 13%, P = 0.003). CONCLUSIONS One year after MMVR, the association of aspirin with OAC reduce d thrombi and thromboembolic events, but not morbidity, due to an increase in hemorrhagic complications. (C) 2000 by the American College of Cardiolog y.