Using Markers of Left Ventricular Filling Pressure to Predict Mortality in Mild to Moderate Aortic Stenosis: Insights from the National Echo Database of Australia (NEDA)

Abstract

Background: Echocardiographic measures of elevated left ventricular filling pressure (LVFP) predict a worse prognosis in many conditions. We hypothesised that they would reflect the haemodynamic consequences of aortic stenosis (AS) and be useful in predicting survival in this setting. The current study tested this in patients with mild-moderate AS. Objective: To determine the relationship between acute (ratio of early transmitral flow to mitral annular velocities; E/E’) and chronic (indexed left atrial volume; LAVI) markers of LVFP and mortality in mild-moderate AS. Method: Retrospective analysis of data from the National Echo Database of Australia. The first record for patients >18 years showing mild-moderate AS (mean gradient 10–40 mmHg) or no AS (<10 mmHg) was included. Data on sex, age, examination date and death were also recorded. Results: 134,500 patients were included; 53% male, mean age 63 years, mean follow-up 4.6 years, 25,929 (19%) mild-moderate AS and 108,571 (81%) no AS. The hazard ratio (HR) for mortality in mild-moderate versus no AS was 1.11 (95% CI 1.08–1.13), adjusted for age and sex. In mild-moderate AS, LAVI >34 ml/m2 (HR = 1.96) and E/E’ >14 (HR = 2.15) were associated with an increased risk of death and remained independently predictive of survival (LAVI >34 HR = 1.26 and E/E’ HR = 1.45) in a multivariate model that also included age, sex and LV ejection fraction. Conclusion: Our data confirm higher mortality associated with mild-moderate AS compared to no AS. Indices of LVFP independently predict death in this group and may be useful in risk-stratifying patients prior to developing severe AS.