In Vivo Calcium Score Measurement After Freestyle Full Root Replacement in Young Adults

A recent update of the American Hear Association and American College of Cardiology Guidelines for the Management of Patients With Valvular Heart Disease1 recommended that for patients between 50 and 70 years of age, it is reasonable to the choice of either a mechanical or bioprosthetic valve; the threshold for biological valves continues to decrease and more younger adults will receive this kind of prosthesis. However the best biological option for these patients is still a matter of debate. Stented bio-prosthesis is the most common choice. However, the predicted 15-year risk of needing reoperation because of structural deterioration is 22% for patients 50 years of age2.

In the late 80's stentless valve as the Medtronic Freestyle (FS) has been introduced with the hope that it may provide physiological flow in the aortic root, sinuses, and coronary orifices and a low risk of thromboembolism. Several randomized study and meta-analysis demonstrated improved hemodynamic, a larger orifice area and a midterm survival advantage of stentless aortic valve compared to stented aortic valve replacement3, 4. The FS valve is believed to provide greater durability and superior hemodynamic performance due to the low mechanical stress on the leaflet tissues. The failure mode of the FS is thought to be mostly calcification of the aorta wall and cusp tears because collagen degradation5. This phenomenon is inflammation mediated process.

Aim of this study is to evaluate the rate and anatomy of the aortic wall and leaflet calcification of the FS prosthesis implanted as full root in patients younger than 60 years compared to a stented bioprostheses (Perimount Magna Ease, PM). A 3D CT scan will be used to assess the calcification score and to determine the relationship between calcification and aortic valve leaflet.

Between 2007 and 2017, among patients younger than 60 years of age, 51 patients underwent a full root replacement with a FS and 49 received a Perimount Magna Ease prosthesis. Those patients will undergo a 3D CT scan. The group of the patient with PM will be matched in function of age and interval of follow-up with the FS group.

A transthoracic echocardiogram will be performed to check residual valve insufficiency and trans-valvular gradients. A cardiopulmonary exercise test ( with extraction of maximal oxygen consumption ) combined with a trans thoracic echocardiography (stress echocardiography) will be performed to evaluate the patients exercise capacity and its influence on the cardiac and valve function.