Duration of myocardial early systolic lengthening for diagnosis of coronary artery disease

Abstract

Objective: Myocardial early systolic lengthening (ESL) duration is prolonged in patients with coronary artery disease (CAD). However, the relationship between the fractional flow reserve (FFR), the current gold standard for evaluating physiological myocardial ischaemia, and ESL has not been studied. The aims of this study were to investigate whether left ventricular (LV) ESL duration could identify patients with CAD, and to examine the relationship between FFR and LV ESL duration.

Methods: In this single-centre, cross-sectional, prospective study of 75 patients with suspected or known CAD, we performed two-dimensional speckle tracking echocardiography at rest on the day before coronary angiography or percutaneous coronary intervention. Apical 3 views were used to examine ESL duration, defined as time from onset of the Q wave to maximum myocardial systolic lengthening.

Results: Thirty-five patients had non-significant stenosis. Forty patients with CAD underwent FFR testing: 17 had an FFR≥0.8 and 23 had an FFR<0.8. Global ESL duration was 20.9±22.2 ms in patients with non-significant stenosis, 36.4±23.2 ms in patients with FFR≥0.8 and 39.6±29.5 ms in patients with FFR<0.8 (p=0.020). However, global and regional ESL durations were not significantly correlated with FFR and demonstrated poor reproducibility.

Conclusion: Although myocardial ESL duration was significantly prolonged in patients with CAD compared with patients without CAD, ESL at rest showed poor reproducibility, and this new parameter did not predict FFR in patients with suspected CAD.

Keywords: fractional flow reserve; myocardial ischaemia; speckle tracking echocardiography.

Figure 1

Representative example of LV early systolic lengthening duration using two-dimensional speckle tracking echocardiography (A) and 18-LV segment model (B). LAD, left anterior descending coronary artery; LCX, left circumflex; LV ESL, left ventricular early systolic lengthening; RCA, right coronary artery.

Figure 2

Myocardial deformation in patients with and without coronary artery disease measured by LV GLS levels (A), postsystolic shortening (B), LV peak positive early strain (C), and duration of LV ESL (D). The bottom and top whiskers indicate the fifth and 95th percentile levels, respectively; the lower and upper boundaries of the boxes, the 25th and 75th percentile levels, respectively; and the horizontal line within the box, the median level. CAD, coronary artery disease; FFR, fractional flow reserve; LV ESL, left ventricular early systolic lengthening; LV GLS, left ventricular global longitudinal strain; nsCAD, non-significant coronary artery disease.

Figure 3

Correlation between fractional flow reserve and duration of (A) global LV ESL, (B) regional LV ESL, (C) regional LV ESL (first three longest segments) in the LAD, and (D) regional LV ESL (first three longest segments) in non-LAD. DESL, duration of ESL; ESL, early systolic lengthening; LAD, left anterior descending coronary artery; LV, left ventricular.

Figure 4

Receiver operating characteristic (ROC) curves for detecting (A) patients with coronary artery disease and (B) patients with FFR<0.8 in global measurements. The AUC for duration of LV ESL was the highest, with optimal ROC cut-off points of 13.4 ms (A) and 21.2 ms (B), respectively. AUC, area under the ROC curve; FFR, fractional flow reserve; LV ESL, left ventricular early systolic lengthening; LV GLS, left ventricular global longitudinal strain; PSS, postsystolic shortening.