Low target-INR anticoagulation is safe in selected aortic valve patients with the Medtronic Open Pivot mechanical prosthesis: long-term results of a propensity-matched comparison with standard anticoagulation

Abstract OBJECTIVES: To investigate the long-term results of a low international normalized ratio (INR)-anticoagulation program in selected patients after aortic valve replacement (AVR) with the Medtronic Open Pivot mechanical heart valve (OPMHV). METHODS: From January 1993 to December 2012, 909 OPMHV valves were used for single AVR. Patients with preserved sinus rhythm and left ventricular function (Low-INR, n = 552), were managed to an INR of 1.5–2.5 and compared to patients (Standard-INR, n = 357) treated with standard anticoagulation (INR 2.5–3.5). Long-term outcome was analysed for survival and valve-related events, on propensity score matched pairs of 169 patients/group. RESULTS: Within a follow-up cumulating 3096 patient-years, 10- and 15-year survival was significantly better for Low-INR patients: 79% and 63% vs 63% and 34% (P