Introduction:
Low-flow significant aortic stenosis (AS) with preserved left ventricular ejection fraction (LVEF>50%) is associated with worse clinical outcomes. In classical severe AS, guidelines have indicated that deterioration of LVEF to <50% is a Class I indication for aortic valve replacement. However, predictors of LVEF deterioration in patients with low-flow AS have not been studied. We developed a model, based on clinical and echocardiographic parameters to predict LVEF deterioration to <50%.
Methods:
Consecutive subjects (n=162) with low-flow (stroke volume index <35mg/ml) significant AS and paired echocardiographic studies (>180 days apart) were studied. Significant predictors of LVEF deterioration on univariate analyses were fit into a multivariable logistic regression. A risk score was then developed by converting the B-coefficients into weights, and its performance in predicting the LVEF deterioration to <50% was evaluated.
Results:
There were 50 patients (30.9%) with significant deterioration of LVEF to <50% from baseline. A risk score was developed based on five clinical and echocardiographic predictors (History of hypertension (p=0.008) – 1 point, initial LVEF <65% (p=0.012) – 2 points, Tissue Doppler S’ velocity <7.3cm/s (p=0.049) – 1 point, End-systolic wall stress >70g/cm2 (p=0.001) – 2 points, and left ventricular mass index >100g/m2 (p=0.010) – 1 point). The risk score performed well under receiver operating characteristic curve (AUC=0.78, 95%CI 0.72-0.85, p<0.001). A score of 4 points or more was the optimal cut-off, predicting most cases (98%, 48 out of 50).
Conclusions:
Despite preserved LVEF, subclinical myocardial dysfunction may represent an important comorbidity in patients with low-flow AS, which may accelerate inappropriate left ventricular remodelling. The risk score may be used to identify patients at risk of significant LVEF deterioration, thereby allowing for closer monitoring and earlier surgical intervention.
Angiographic predictors of left ventricular ejection fraction after successful angioplasty in acute myocardial infarction: An angiographic risk score for use in the catheterization laboratory
