Two innovative aortic bioprostheses evaluated in the real-world setting. First results from a two-center study.

Background: The increasing use of biological substitutes for surgical aortic valve replacement (AVR), has led to the development of new bioprostheses with improved hemodynamics and expected durability.

Methods: In this observational retrospective two-center cohort study, two innovative bioprostheses, INSPIRIS Resilia and AVALUS were analyzed. We analyzed early and 2.4-year follow-up results in terms of safety, clinical outcome and hemodynamic performance.

Results: From November 2017 to February 2021, 148 patients underwent AVR with INSPIRIS Resilia (N.=74) or AVALUS (N.=74) bioprosthesis. The 30-day and mid-term mortality was comparable (1% vs. 3%, P=0.1 and 7% vs. 4%, P=0.4, respectively). Valve-related mortality was observed in one AVALUS patient. Three (4%) patients of the AVALUS group developed prosthetic endocarditis and two of them died after reoperation. No other cases of prosthetic endocarditis were observed. No cases of structural valve degeneration or significant paravalvular leak were detected at follow-up. Median follow-up peak pressure gradient was 21 vs. 23 mmHg (P=0.4) and the mean pressure gradient was 12 vs. 13 mmHg (P=0.9) for Inspiris and AVALUS, respectively. The effective orifice area (EOA) and indexed EOA were 1.5 cm² vs. 1.4 cm² (P=0.4) and 0.8 vs. 0.7 cm²/m² (P=0.5), respectively. Indexed left ventricular mass regression was -33 vs. -52 g/m² for the Inspiris and AVALUS groups, respectively, (R²-adjusted =0.14; P<0.01).

Conclusions: INSPIRIS Resilia and AVALUS bioprostheses were reliable with comparable results in safety, clinical outcome and hemodynamic performance. After statistical adjustment, AVALUS was associated with better left ventricular mass reduction. Long-term follow-up would provide definitive comparative results.