Stress Echo Image Acquisition Quality is Dramatically Improved by a Novel Image Audit Program

Abstract

Introduction: Timely acquisition of on-axis images with good endocardial visualisation is imperative for accurate interpretation of stress echocardiographic (SE) images and diagnosis of inducible ischaemia. Method: Quarterly image audits of 5% (n=636) of all SE (n= 12720) from April 2014 to December 2015 performed at HeartCare Partners were conducted by 2 randomly selected experienced sonographers. Peak-stress images were scored for endocardial definition (Wall Clarity Score (WCS): 0 inadequately visualised; 1 suboptimal definition; 2 well defined); on- vs. off-axis image obtained, and resting vs. peak-stress images matching. Result: Time taken to complete peak image acquisition from exercise cessation was <40s in 12%, 40-69s in 68% and <90s in the remainder. High quality peak-exercise endocardial definition was obtained overall (WCS: 1.83±0.04) with the inferior, inferoseptal and anteroseptal walls best visualised (WCS: 1.87±0.02), with the anterior, anterolateral and inferolateral walls proving more challenging (WCS: 1.80±0.02, p<0.001). Resting on-axis imaging improved from 82±5% to 91±2%. Peak images improved from 63±11% to 85±3% (p<0.001). Pre-/post-stress image matching improved across observation period (76±2% vs. 85±4%, p<0.05). Summary: Whilst previous stress echo validation studies have assessed diagnostic accuracy and inter-observer variability, the use of this novel image audit program has produced dramatic and clinically important improvements in endocardial definition, on-axis acquisition and pre-/post-exercise image matching.