Prosthesis-patient mismatch affects long-term survival after mechanical valve replacement.

Area of Science:

• Cardiovascular Surgery
• Biomedical Engineering
• Clinical Outcomes Research

Background:

• Prosthesis-patient mismatch (PPM) is a potential complication after aortic valve replacement (AVR).
• The impact of PPM on long-term survival following mechanical AVR requires further investigation.

Purpose of the Study:

• To evaluate the association between the degree of PPM and long-term survival in patients undergoing mechanical AVR.
• To identify predictors of significant PPM in this patient cohort.

Main Methods:

• Analysis of prospectively collected data from 469 patients who underwent AVR between 1995 and 1998.
• Indexed effective orifice area (iEOA) used to define PPM severity: moderate (0.65–0.85 cm²/m²) and severe (<0.65 cm²/m²).
• Cox proportional-hazards model with propensity score adjustment for survival analysis.

Main Results:

• PPM occurred in 43% of patients: minimal (57%), moderate (39%), and severe (4%).
• Predictors of significant PPM included small valve size, obesity, older age, and advanced heart failure.
• Long-term survival was significantly lower in patients with moderate (63%) and severe (47%) PPM compared to minimal PPM (77%) (P < .001).
• Moderate or severe PPM was an independent predictor of poorer survival (adjusted HR, 1.2; P = .05).

Conclusions:

• Prosthesis-patient mismatch is prevalent in mechanical AVR and is associated with reduced long-term survival.
• Significant PPM adversely affects outcomes, highlighting the importance of considering mismatch in AVR selection and planning.