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Updated: Aug 8, 2026
Full-root Aortic Valve Replacement by Stentless Aortic Xenografts in Patients with Small Aortic Roots
Published on: May 21, 2017
Patient-prosthesis mismatch does not affect survival following aortic valve replacement
Neil J Howell1, Bruce E Keogh, Vivien Barnet
1Department of Cardiothoracic Surgery, University Hospital NHS Foundation Trust, Birmingham, UK.
Objective:
Patient-prosthesis mismatch (PPM) has been reported to increase perioperative mortality and reduce postoperative survival in patients undergoing aortic valve replacement (AVR). We analysed the effect of PPM at values predicting severe mismatch on survival following AVR in our unit.
Methods:
Prospectively collected data on 1481 consecutive patients who had undergone AVR with or without coronary artery revascularisation between 1997 and 2005 were analysed. Projected in vitro valve effective orifice area (EOA) and geometric prosthesis internal orifice area (GOA) were evaluated and values were indexed to body surface area (cm(2)m(-2)). PPM was defined as EOAi<0.6 and/or GOAi<1.1. Long-term survival data were obtained from the National Institute of Statistics.
Results:
One thousand four hundred and eighteen patients were identified. 67/1418 (4.7%) patients had GOAi<1.1; 122/1418 (8.6%) had EOAi<0.6 and 38 (2.6%) patients exhibited both forms of mismatch. One thousand two hundred and sixty-seven patients (89%) demonstrated no mismatch (reference group). There were 75 in-hospital deaths (overall mortality 5.3%) with no significant difference between the mismatch and the reference groups. Survival data were available for up to 8 years (median 36 months, IQR 6-60 months). There were 160 late deaths (13/143 PPM group vs 147/1198 reference group). The 5-year survival estimate was similar for both groups (83% PPM group; 81% reference group; p=0.47). Cox-hazard analysis identified advanced age as the only predictor of reduced survival (age>80, RR 2.13, 95% CI 1.38-4.586, p=0.004).
Conclusions:
Severe patient-prosthesis mismatch was predicted in 4-10% of patients undergoing AVR but this did not affect in-hospital mortality or mid-term survival.
Insights
Severe patient-prosthesis mismatch (PPM) after aortic valve replacement (AVR) was found in 4-10% of patients. This mismatch did not impact in-hospital mortality or mid-term survival rates.
Area of Science:
- Cardiovascular Surgery
- Biomedical Engineering
- Clinical Outcomes Research
Background:
- Patient-prosthesis mismatch (PPM) is a potential complication following aortic valve replacement (AVR).
- Previous studies suggest PPM may increase perioperative mortality and decrease long-term survival.
- The clinical significance of severe PPM following AVR requires further investigation.
Purpose of the Study:
- To analyze the effect of severe patient-prosthesis mismatch on survival after AVR.
- To evaluate the incidence of severe PPM in patients undergoing AVR in a specific clinical unit.
- To identify predictors of survival in patients following AVR.
Main Methods:
- Prospective data collection from 1481 patients undergoing AVR between 1997 and 2005.
- Evaluation of projected in vitro valve effective orifice area (EOA) and geometric prosthesis internal orifice area (GOA), indexed to body surface area.
- Definition of severe PPM as EOAi<0.6 and/or GOAi<1.1; long-term survival data obtained from national statistics.
Main Results:
- Severe PPM (EOAi<0.6 or GOAi<1.1) was identified in 4.7% to 8.6% of patients (combined 2.6%).
- No significant difference in in-hospital mortality (5.3% overall) between mismatch and reference groups.
- Five-year survival estimates were similar (83% PPM group vs. 81% reference group; p=0.47), with advanced age (>80) as the only predictor of reduced survival.
Conclusions:
- Severe patient-prosthesis mismatch occurs in a small percentage of AVR patients (4-10%).
- This degree of mismatch did not adversely affect in-hospital mortality.
- Mid-term survival following AVR was not significantly impacted by severe patient-prosthesis mismatch.
