Dynamic assessment of global longitudinal strain after isometric exercise to predict functionally significant coronary lesion

TL;DR

This study shows that measuring heart muscle strain during isometric exercise can help identify significant coronary artery blockages in patients with chronic heart disease.

Contribution

The study introduces dynamic global longitudinal strain during isometric hand-grip exercise as a novel non-invasive method for coronary lesion assessment.

Findings

ΔGLS showed strong correlation with FFR (r = 0.660, P < 0.001).

A ΔGLS threshold of 0.35 had high sensitivity (92%) and specificity (85%) for significant lesions.

44% of patients had functionally significant coronary lesions based on FFR.

Abstract

There is still a wide debate regarding the management of patients with chronic coronary syndrome, the choice of optimal non-invasive stress test, and the decision for coronary revascularization. Evidence has accumulated demonstrating the utility of global longitudinal strain (GLS) as a predictor of significant coronary disease. To evaluate the application of speckle tracking during resting echocardiography and after isometric loading with the hand-grip test, and to compare GLS parameters with fractional flow reserve (FFR).

Patients with known CCS who underwent angiography with evidence of coronary stenosis >40%<90% and were referred for functional assessment were enrolled in this study. Patients with previous MI, depressed LV systolic function, and poor acoustic window were excluded. Patients underwent a standard echocardiography with recordings suitable for LV speckle tracking. Subsequently, a dynamic hand-grip test was performed for 3 min, then the same images were captured. Global longitudinal strain was calculated at rest (rGLS), under stress conditions (sGLS), as well as the absolute difference between the two measurements – ΔGLS. Then, patients underwent invasive functional assessment with measurement of the FFR of the coronary lesion. Correlation analysis of myocardial strain parameters and FFR was performed. A total of 106 patients were included in the study. The mean rGLS was −18.5 ± 1.8, sGLS: −19.1 ± 2.0 and ΔGLS: 0.62 ± 1.4. In total, 44% of patients had a functionally significant coronary lesion when assessed with FFR. There was a statistically significant correlation between ΔGLS and FFR values, r = 0.660, P < 0.001. ΔGLS of 0.35 showed good diagnostic performance capacity (AUC 0.896, 95% CI: 0.83–0.96, specificity 85%, sensitivity 92%) for a functionally significant coronary lesion.

Dynamic GLS during isometric hand-grip exercise is a feasible method for functional assessment in patients with chronic coronary syndrome.

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