Long-term clinical outcomes in patients between the age of 50-70 years receiving biological versus mechanical aortic valve prostheses

Abstract

Objectives: The last 2 decades have seen an incremental use of biological over mechanical prostheses. However, while short-term clinical outcomes are largely equivalent, there is still controversy about long-term outcomes.

Methods: All patients between the ages of 50 and 70 years undergoing elective/urgent isolated aortic valve replacement at our institute between 1996 and 2023 were included. Trends, early, and long-term outcomes were investigated.

Results: A total of 1708 (61% male) patients with a median age of 63.60 (interquartile range: 58.28-67.0) years were included of which 1191 (69.7%) received a biological prosthesis. After inverse propensity score weighting, there were no short-term differences when comparing patients receiving biological and mechanical valves. However, patients who received mechanical prostheses had better long-term survival (P < 0.001). Sub-group analysis revealed that patients with biological size 19 mm prosthesis had the worst long-term survival. Patients with a size 21-mm mechanical prosthesis had better survival compared to both size 19-mm [hazard ratio (HR) 0.25, 95% confidence interval (CI) 0.17-0.37, P < 0.001], 21-mm (HR 0.33, 95% CI 0.23-0.48, P < 0.001) and 23-mm (HR 0.40, 95% CI 0.27-0.60, P < 0.001) biological prosthesis. Additionally, patients with severe patient-prosthesis mismatch exhibited the lowest survival rate compared to those with moderate or no (HR 1.56, 95% CI 1.21-2.00, P < 0.001).

Conclusions: Patients aged between 50 and 70 years with a mechanical aortic prosthesis had better long-term survival compared to those with a biological prosthesis. Our study underscores the need for a critical re-evaluation of prosthesis selection strategies in this age group.

Keywords: Aortic valve replacement; Biological prosthesis; Mechanical prosthesis; Transcatheter aortic valve replacement.

Graphical abstract

Figure 1:

The trend in the number of biological and mechanical aortic valve prosthesis used from 1996 to 2022.

Figure 2:

Survival in patients who received biological or mechanical aortic valve prosthesis in the whole cohort before propensity score matching.

Figure 3:

The long-term survival in patient’s age between 50 and 70 years receiving biological or mechanical aortic valve prostheses in the propensity score matching cohort (0: biological, 1: mechanical). IPTW: inverse probability of treatment weighting.

Figure 4:

The freedom from repeat valvular intervention in patients age between 50 and 70 years receiving biological or mechanical aortic valve prostheses in the propensity score matching cohort (0: biological, 1: mechanical). IPTW: inverse probability of treatment weighting.

Figure 5:

The Kaplan–Meier curve in patients age between 50 and 70 years receiving aortic valve size 19, 21 and 23 mm after propensity score matching, subclassified by prosthesis type (0: 19-mm biological, 1: 21-mm biological, 2: 23-mm biological, 3: 19-mm mechanical, 4: 21-mm mechanical). IPTW: inverse probability of treatment weighting.

Figure 6:

The Kaplan–Meier curve for patients with no, moderate, and severe prosthesis mismatch after surgical aortic valve replacement in the whole cohort (0: no, 1: moderate, 2: severe prosthesis mismatch). PPM: patient–prosthesis mismatch.