The goal of this observational study o is to compare outcomes after either biological or mechanical aortic valve replacement. The main question it aims to answer:

Is survival better after mechanical aortic valve replacement compared to biological aortic valve replacement? Are there less complications and reoperations after mechanical aortic valve replacement compared to biological aortic valve replacement? We perform a retrospective Data Collection of anonymized Austrian health insurance data.

Objectives: In recent years, age recommendations for the utilization of biological prostheses rather than mechanical prostheses for surgical aortic valve replacement (sAVR) have been significantly reduced. This study evaluated survival rates, major adverse cardiac events (MACEs), and reoperation risks following surgical (sM-AVR) and biological (sB-AVR) AVR, with the aim of providing data to inform optimal prosthesis selection for middle-aged patients between 50 and 65 years.

Methods: A population-based cohort study was conducted using data from the Austrian Health System from 2010 to 2020. Patients undergoing isolated sAVR (n=3761) were categorized into sM-AVR (n=1018) and sB-AVR (n=2743) groups. Propensity score matching (PSM) was applied to balance covariates. The primary endpoint was all-cause mortality. The secondary endpoints included MACEs, reoperation, stroke, bleeding, and post-reoperation survival. Outcomes were assessed using Cox regression and Kaplan-Meier analyses.

Inclusion Criteria:

• age between 50 and 65 years
• st. p. isolated biological or mechanical aortic valve replacement

Exclusion Criteria:

• transcatheter aortic valve implantation (TAVI; MEL codes DB025, DB026, DB021, or XN010) as index procedure
• age <50 or >65 years
• concomitant heart surgery or additional procedures during the index operation
• patients receiving a coronary artery stent (MEL codes DD050 or DD060) within four months before AVR

• age between 50 and 65 years
• st. p. isolated biological or mechanical aortic valve replacement