P402 PROSTHETIC MECHANICAL VALVE THROMBOSIS: THE EXPERIENCE OF SALAM CENTRE FOR CARDIAC SURGERY (EMERGENCY NGO)

Abstract Mechanical heart valve (MHV) replacement in patients with rheumatic valve disease is common in Africa. MHV requires long–life anticoagulation (OAT) and managing this can be difficult. Prosthetic valve thrombosis (VT) is a pathological entity characterized by thrombus formation on the prosthetic structures, with subsequent prosthesis dysfunction. Salam Centre for Cardiac Surgery was built in Khartoum Sudan by Emergency NGO. Since April 2007 high–quality and free–of–charge medical and cardio–surgical treatment has been offered to patients. More than 10000 cardiac surgery, 80% of which for MHV replacement, were performed. The aim of the work is to analyze the characteristics of patients with VT, the risk factors and clinical follow–up. From Aug 1, 2018 to Nov 30, 2022, 287 VT involving 237 patients were collected.The incidence is 1.36% p/y. The most relevant risk factor was the interruption of anticoagulant therapy and irregular INR control (N. 142; 49,5%). In 101 cases (35,2%) a clinical factor (infection, pregnancy, eosinophilia, heart failure) was the main cause of VT. The diagnosis, suspected with the Transthoracic Echo and confirmed with fluoroscopy, was done at the OPD visit (32,4%) in asymptomatic or at triage for symptomatic patients (67,6%). 236 patients were admitted to Salam Centre.The treatments of choice were thrombolysis, performed with 2 different protocols, fast and low dose–slow infusion (Alteplase 25 mg./6 hrs), followed by Triple Therapy (TT) (Warfarin, LMWH and Aspirin) (N.189–65,8%), TT alone (N.44– 15,3%) or Warfarin and Aspirin (N.54–18,8%). 210 events (73,2%) ended with unblocked valve,24 events ended with the death of the patient (8,3%); low dose/slow infusion regimen had less deaths. Thrombolysis was more effective (unblockage 79,9%). Warfarin and Aspirin and not admission to Salam Centre were linked to less unblokage and high mortality rate. Conclusions The incorrect conduct of OAT represents the most relevant risk factor for VT.Many are the underlying causes, from economic and social factors to insufficient patient awareness. MOH intervention to offer free of charge INR check, but also patient education must be improved. VT is caused also by intercurrent clinical events such as pregnancy, infection. Eosinophilia represents a chapter that deserves a detailed study.Patients with history of VT must be followed by a dedicated clinic that aims to increase patient loyalty in order to intercept risk factors as early as possible.