Inter-observer and Inter-vendor Variability in Strain Measurements in Patients with Single Right Ventricular Anatomy

Area of Science:

• Cardiology
• Medical Imaging
• Biomedical Engineering

Background:

• Myocardial strain analysis provides novel insights into ventricular function.
• Limited data exists on strain analysis in single right ventricle (sRV) physiology.
• Software variability may impact clinical interpretation of strain measurements.

Purpose of the Study:

• To compare two commercial strain software applications (VVI and AFI) in patients with sRV.
• To evaluate inter-vendor and inter-observer variability of myocardial strain measurements.
• To assess the clinical reliability of strain analysis in sRV patients.

Main Methods:

• Prospective evaluation of echocardiograms from 85 sRV patients (122 studies) with Glenn/Fontan palliation.
• Longitudinal 4-chamber, inflow/outflow, circumferential, and radial strain assessed using VVI and AFI software.
• Inter-observer variability assessed by two sonographers on a subset of 45 patients (61 studies).

Main Results:

• Moderate correlation observed between VVI and AFI measurements (Circumferential strain R=0.77).
• Both software packages demonstrated modest inter-observer reproducibility for longitudinal and circumferential strain.
• Mean strain differences between vendors were minimal (≤1%), except for radial and VVI IO inferior strain.

Conclusions:

• While inter-observer variability is modest with minimal mean differences, suggesting clinical reliability, inter-vendor variability is greater.
• Serial myocardial strain assessments in sRV patients should utilize the same software package to ensure consistency.
• Further research is needed to standardize strain analysis protocols for complex single ventricle physiology.