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

Abstract

Outcomes after surgery for low-gradient AS were prospectively assessed in 152 consecutive patients from seven institutions. There were 113 men (74%); mean age was 72 years (64-76); valve area, 0.7 cm(2) (0.6-0.8); left ventricular (LV) ejection fraction 0.31 (0.25-0.37) and baseline mean transaortic pressure gradient (MPG), 30 mmHg (25-35) Among 139 patients with available prosthetic valve effective orifice area (EOA), PPM (defined by an indexed EOA < or = 0.85 cm(2)/m(2)) was present in 79 patients (57%) and had no significant impact on post-operative mortality. Independent predictors of overall mortality were LV contractile reserve [hazard ratio (HR) 0.52; 95% confidence interval (CI) 0.35-0.78; P = 0.002], associated coronary artery bypass grafting (HR 1.87; 95% CI 1.24-2.82; P =0.003), baseline MPG (per 1 mmHg decrease to 10 mmHg; HR 1.03; 95% CI 1.01-1.06; P = 0.021), previous cancer (HR 2.13; 95% CI 1.05-4.29; P = 0.037), and logistic EuroSCORE (per 1% increase; HR 1.02; 95% CI 1.01-1.04; P = 0.040). CONCLUSION In this large multicentre series of patients with low-gradient AS, we found that PPM (moderate in most cases) had no influence on post-operative mortality. Therefore, the performance of more complex interventions in order to avoid moderate PPM may not be justified in the setting of low-gradient AS, because their higher risk probably outweighs the expected benefit.

Impact of Prosthesis-Patient Mismatch on Long-Term Survival After Aortic Valve Replacement

“…Differences in age distribution, prevalence of obesity, and prevalence of moderate versus severe PPM in the patient populations may also help explain the discrepancies observed among previous studies. To this effect, studies conducted in younger patient populations (3,25) generally found that PPM has a significant impact on late survival; studies in elderly populations (11,12) often failed to demonstrate any significant association. Interaction between PPM and age.…”

Valve prosthesis-patient mismatch: hemodynamic, echocardiographic and clinical consequences

“…Alternatively, while some researchers have defended the hypothesis that PPM affect survival and/or functional class [15,16], others consider it a phenomenon with no clinical importance or that only affects the prognosis in young patients and in patients of any age with ventricular dysfunction [17,18].…”

Outcome After Aortic Valve Replacement for Low-Flow/Low-Gradient Aortic Stenosis Without Contractile Reserve on Dobutamine Stress Echocardiography

“…Gray's piecewise-constant time-varying coefficients survival model is an extension of the Cox proportional hazards model that allows the regression coefficients to change over different time intervals (16). It has, therefore, the ability to estimate how the hazards of individual risk factors change over time (6,16) and may be better suited for modeling survival after cardiac surgery. We used single-variable Gray models to identify variables associated with 5-year overall mortality.…”