Oral anticoagulation in carriers of mechanical heart valve prostheses: experience of ten years.

BACKGROUND Published data suggest that rates of thromboembolism and bleeding, in patients with mechanical heart valve prostheses, can be very small by optimizing current anticoagulant therapy. OBJECTIVE To evaluate the occurrence of complications in patients with mechanical heart valve prostheses undergoing anticoagulant therapy optimized through specialized clinics. METHODS We studied the occurrence of complications over 10 years in 261 anticoagulated patients with mechanical heart valve prostheses, followed in specialized clinics. These patients were divided into two groups according to percentage of queries with prothrombin time (INR) within the desired range: G1-0% to 50.00% and G2-50.01% to 100% of appointments. We evaluated the occurrence of thromboembolic and bleeding complications in their entirety or subdivided into major and minor, according to gravity. The results are presented in an actuarial study and frequency of occurrence of linear events. RESULTS The actuarial study showed that, over time, more G2 (with 50.01% to 100% of the consultations with INR in desired range) more patients were free of the occurrence of any event, of minor bleeding events or the marked increase of RNI. The linearized frequency of occurrence in all types events, were also lower in group G2. CONCLUSIONS The period of time that patients that remain within the desired anticoagulation interval has directly relations with occurrence of complications. Even with careful follow-up at a specialized outpatient unit, only approximately one third of the patients showed an adequate anticoagulation level in more than half of the consultations.