Durability and prevalence of aortic regurgitation nine years after aortic valve replacement with the Toronto SPV stentless bioprosthesis

Background and aim of the study: Stentless aortic bio-prostheses have excellent hemodynamics. Previous investigations of the Toronto SFV valve described a correlation between the occurrence of significant aor-tic regurgitation (AR) and dilation of the sinotubular junction. The study aim was to determine the long-term durability and determinants of AR at nine years in a large, multicenter study of the Toronto SPV valve. Methods: The study included 447 patients from six centers. Clinical outcomes and echocardiographic data (gradients, effective orifice area index (EOA-I), left ventricular mass, aortic root dimensions, and presence and severity of AR) were collected prospec-tively. A multivariable logistic regression model was used to evaluate clinical and echocardiographic vari-ables for impact on the occurrence of AR. Results: Total follow up was 2,660 patient-years (mean 6.0 ± 2.5 years; range: 0 to 11.1 years). Mean gradient and EOA-I remained unchanged through nine years. There were 17 cases of structural deterio ration, of which 15 underwent explantation. The mechanism of failure was predominantly leaflet tear in the setting of sinotubular dilation. Freedom from expiant for structural failure was 90.1% at nine years (100% for patients aged ≥65 years). Freedom from hemodynamically significant AR was 96.9% at five years and 82.5% at nine years. Determinants of AR were longer duration of follow up, larger valve size, and increase in the ratio of sinotubular junction to the size of valve implanted. Conclusion: At nine years after implantation of the Toronto SPV valve, hemodynamics remained excel-lent. There was good freedom from structural deteri-oration through nine years, and structural failure occurred due to aortic root dilation and leaflet tear, without significant valve calcification. AR tends to occur with longer follow up, larger valve sizes, and dilation of the sinotubular junction.