  The cardiologist's main tool for measuring systolic heart failure is left
ventricular ejection fraction (LVEF). Trained cardiologist's report both a
visual and machine-guided measurement of LVEF, but only use this machine-guided
measurement in analysis. We use a Bayesian technique to combine visual and
machine-guided estimates from the PARTNER-IIA Trial, a cohort of patients with
aortic stenosis at moderate risk treated with bioprosthetic aortic valves, and
find our combined estimate reduces measurement errors and improves the
association between LVEF and a 1-year composite endpoint.
