Figure 4. Correlation between myocardial strain and stenosis severity.

Scatter plots showing the relation of myocardial strain to stenosis severity demonstrated weak non-linear correlations for Sreserve (a), (r2=0.38), and for SRreserve (d), (r2=0.56). SRreserve was reduced already with moderate coronary stenosis (e), while a significant reduction in Sreserve required higher grade stenotic lesions (b). ROC analysis showed that SRreserve, with a cut-off value of SRreserve>1.64, is a highly accurate parameter for the detection of coronary artery stenosis≥50% (f).