Citations

ObjectivesTo quantify the bias of shear wave speed (SWS) measurements between different commercial ultrasonic shear elasticity systems and a magnetic resonance elastography (MRE) system in elastic and viscoelastic phantoms.MethodsTwo elastic phantoms, representing healthy through fibrotic liver, were measured with 5 different ultrasound platforms, and 3 viscoelastic phantoms, representing healthy through fibrotic liver tissue, were measured with 12 different ultrasound platforms. Measurements were performed with different systems at different sites, at 3 focal depths, and with different appraisers. The SWS bias across the systems was quantified as a function of the system, site, focal depth, and appraiser. A single MRE research system was also used to characterize these phantoms using discrete frequencies from 60 to 500 Hz.ResultsThe SWS from different systems had mean difference 95% confidence intervals of ±0.145 m/s (±9.6%) across both elastic phantoms and ± 0.340 m/s (±15.3%) across the viscoelastic phantoms. The focal depth and appraiser were less significant sources of SWS variability than the system and site. Magnetic resonance elastography best matched the ultrasonic SWS in the viscoelastic phantoms using a 140 Hz source but had a − 0.27 ± 0.027‐m/s (−12.2% ± 1.2%) bias when using the clinically implemented 60‐Hz vibration source.ConclusionsShear wave speed reconstruction across different manufacturer systems is more consistent in elastic than viscoelastic phantoms, with a mean difference bias of < ±10% in all cases. Magnetic resonance elastographic measurements in the elastic and viscoelastic phantoms best match the ultrasound systems with a 140‐Hz excitation but have a significant negative bias operating at 60 Hz. This study establishes a foundation for meaningful comparison of SWS measurements made with different platforms.

Abstract Aims Hypothesis 1 of the Surgical Treatment for Ischemic Heart Failure (STICH) trial enrolled 1212 patients with an LVEF of ≤35% and CAD amenable to coronary artery bypass grafting (CABG). Patients were randomized to CABG and optimal medical therapy (MED) or MED alone. The objective was to assess whether or not patients with diabetes mellitus (DM) enrolled in the STICH trial would have greater benefit from CABG than patients without DM. Methods and results The characteristics and clinical outcomes of patients with and without DM randomized to CABG and MED or MED alone were compared. DM was present in 40%. At baseline, patients with DM had more triple vessel CAD, higher LVEF, and smaller left ventricular volumes. In patients with DM, the primary outcome of all-cause mortality occurred in 39% of patients in the MED group and 39% in the CABG group [hazard ratio (HR) with CABG 0.96, 95% confidence interval (CI) 0.73–1.26]. In patients without DM, the primary outcome occurred in 41% of patients in the MED group and 32% in the CABG group (HR with CABG 0.80, 95% CI 0.63–1.02). While numerically it would appear that the treatment effect of CABG is blunted in patients with DM, there was no significant interaction between DM and treatment group on formal statistical testing. Conclusions Patients with DM enrolled in the STICH trial had more triple vessel disease, smaller hearts, and higher LVEF than those without DM. CABG did not exert greater benefit in patients with DM.