Low-gradient aortic stenosis: impact of prosthesis-patient mismatch on survival

Area of Science:

• Cardiovascular Surgery
• Cardiac Surgery Outcomes
• Aortic Stenosis Management

Background:

• Low-gradient aortic stenosis (AS) presents unique challenges in surgical management.
• Prosthesis-patient mismatch (PPM) is a potential concern after aortic valve replacement.
• The prognostic significance of PPM in low-gradient AS remains debated.

Purpose of the Study:

• To evaluate the impact of prosthesis-patient mismatch (PPM) on outcomes in patients with low-gradient aortic stenosis (AS).
• To identify independent predictors of mortality following surgical intervention for low-gradient AS.

Main Methods:

• A prospective, multicenter study involving 152 consecutive patients with low-gradient AS.
• Assessment of prosthesis-patient mismatch (PPM) defined by indexed effective orifice area (EOA).
• Statistical analysis to determine predictors of overall mortality.

Main Results:

• PPM was present in 57% of patients but did not significantly affect post-operative mortality.
• Independent predictors of mortality included LV contractile reserve, coronary artery bypass grafting, baseline mean transaortic pressure gradient, prior cancer, and logistic EuroSCORE.
• Moderate PPM was common and did not correlate with worse survival.

Conclusions:

• Prosthesis-patient mismatch (PPM) does not appear to influence post-operative mortality in patients with low-gradient aortic stenosis.
• The pursuit of interventions to avoid moderate PPM in this patient group may not be clinically justified.
• Surgical decisions should prioritize established mortality predictors over avoiding moderate PPM in low-gradient AS.