Thromboembolism with low profile bioprosthesis.

Low profile bioprosthesis late follow-up indicates a low incidence of thromboembolism. For the entire series of 415 consecutively operated patients (rigid and flexible stents) the actuarial probability of freedom at 6 years is 90.3% (87.8% for MVR and 92.27% for AVR and 95.24% for MVR + AVR). The linearized incidence for MVR, is 2.5 +/- 0.62 per one hundred patients per year. For AVR this is 1.2 +/- 0.49 per one hundred patients per year. The probability of freedom of thromboembolism of the new flexible stent series (247 patients) at 48 months is 90.92% for MVR, 96.6% for AVR and 100% for MVR + AVR. Endocarditis for the entire series of patients (rigid/flexible stents) at 6 years is low: the linearized incidence for both MVR and AVR is 0.54 per one hundred patients per year. Tissues degeneration, after 5 years follow-up, in patients over 35 years old carrying LPB mounted on flexible stents was not observed. In the series of MVR patients, 17/209 presented thromboembolic complications. In the group of 17 patients, 88% had atrial fibrillation before surgery and 47% of the same group were on warfarin anticoagulation therapy when the embolic accident occurred. The indications for permanent anticoagulation therapy following bioprosthetic MVR in patients with chronic atrial fibrillation is still uncertain.