The Clinical Application of Strain: Raising the Standard

The nice thing about standards…is that you have so many to choose from.

The development of any new technology inevitably involves a different perspective from different engineers and inventors. In the case of strain, all mainstream ultrasound equipment manufacturers as well as makers of independent measurement and reporting software have developed software for the measurement of myocardial deformation from speckle-tracking. Unfortunately, subtle differences in these iterations of software, both between and within manufacturers, have led to variability in measurements between studies that are the result of differences in the technical implementation of speckle-tracking analysis rather than reflecting changes in physiology ( Table 1 ). The implication is that comparative studies of patients across time require the use of the same equipment and possibly the same version of software. Clearly, in most laboratories, this is close to being unmanageable. The introduction of global longitudinal strain (GLS) measurement to diagnostic and management guidelines for cardiotoxicity has increased the urgency of finding a solution, because a 10% to 15% change in strain is used as a criterion for subclinical left ventricular (LV) impairment to predict a subsequent fall in ejection fraction (EF) and guide the institution of cardioprotective therapy.

Table 1

Changes in intervendor discrepancies in speckle-tracking strain measurement over time

Study Year n , clinical setting Acquisition Analysis Reference Mean difference (95% CI) between different methods for measuring GLS
Observed at time of original publication Expected differences based on present study
Bansal et al . 2008 30 IHD GE Vivid 7 EchoPAC vs VVI CMR strain 0.80 (−10.6 to 12.2) 1.0 (−3.1 to 5.2)
Manovel et al . 2010 28 normal GE Vivid 7
Toshiba Artida 4D
EchoPAC vs WM tracking None 0.7 (−2.3 to 3.7) 2.4 (−1.7 to 6.5)
Koopman et al . 2011 34 normal and abnormal (children) GE Vivid 7
Philips iE33
EchoPAC vs TomTec None 1.2 (−5 to 7) −0.7 (−4.0 to 2.7)
Koopman et al . 2011 34 normal and abnormal (children) GE Vivid 7
Philips iE33
QLAB vs TomTec None −0.3 (−8 to 7) −2.7 (−7.0 to 0.6)
Biaggi et al . 2011 47 normal GE Vivid 7 EchoPAC vs VVI None 1.0 (−6.2 to 8.2) 1.0 (−3.1 to 5.2)
Risum et al . 2012 30 normal and abnormal (adults) GE Vivid e9
Philips iE33
EchoPC vs TomTec None 0 (−3.6 to 3.6) −0.7 (−4.0 to 2.7)

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Apr 21, 2018 | Posted by in CARDIOLOGY | Comments Off on The Clinical Application of Strain: Raising the Standard

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