P3697A reappraisal of bioprosthetic aortic valve failure related to structural valve degeneration

Background

Structural valve degeneration (SVD) remains a major complication of aortic bioprostheses.

Purpose

We aimed to assess the mode of SVD leading to bioprosthetic aortic valve failure (BVF) in a large series of patients.

Methods

Between 2010 and 2017, we prospectively enrolled 261 consecutive patients with BVF related to SVD. All patients underwent a clinical work-up. Explanted bioprostheses were analysed for assessing the mechanism of SVD.

Results

The delay from surgery to SVD diagnosis was 8.5±3.3 (1.7 to 21.4) years, 10 years after exclusion of a specific type of bioprosthesis. Of the 261 SVD patients, 150 (57%) had mainly a stenotic type, and 111 (43%) a regurgitant type. In regurgitant SVD bioprosthesis was more frequently porcine (19 vs 7%, P=0.002), prosthesis diameter was larger (23.2±2.5 vs 21.6±1.9 mm; P<0.0001), severe mismatch was less frequent (6 vs 17%, P=0.005), cardiovascular risk factors and especially diabetes, obesity and hypertension were less frequent, patients were more often in NYHA class 3–4 (64 vs 49%; p=0.015), Nt-pro BNP was significantly higher (P<0.0001), and diuretic treatment was more frequent (73 vs 61%, P=0.04). Bioprostheses were explanted during redo surgery in 112 (43%) patients. Of these 112 bioprostheses, moderate to severe calcifications were present in 94 (83.9%) and was the main cause of either stenotic (n=64, 57.1%) or regurgitant SVD. A cusp tear (n=46) accounted for 41.1% of the explanted SVD. A perforation, a recent thrombus or a delamination process were occasionally identified. Structural degeneration developed with minimal calcification in 18 (16.1%) bioprostheses.

Conclusion

Structural valve degeneration remains a matter of concern in current practice with a mean delay of 8 to 10 years after surgery. Beside classical SVD with extensive calcification process other types of SVD can be observed with minimal calcification.