Abstract
Background
Speckle tracking echocardiography with assessment of left ventricular global longitudinal strain (GLS) allows to identify early signs of cardiac dysfunction.
The superiority of GLS in the prediction of all-cause mortality in the general population compared with LVEF is well known; in addiction GLS improves risk stratification and recognize early left ventricular dysfunction in several clinical setting.
Purpose
the aim of this study was to assess the diagnostic and prognostic role of global and segmental strain in the early identification of cardiac dysfunction in patients with myocardial infarction without persistent ST segment elevation (NSTEMI) and without obvious wall motion abnormalities and to assess the ability to predict the presence/extension of coronary artery disease in this population.
Methods
an observational study was carried out enrolling 56 patients (median age 66 ± 11,7 years) admitted for NSTEMI. Electrocardiogram, echocardiogram with global and segmental strain measurement (GE’s Automated Function Imaging) and coronary angiography were performed in all patients. In addition we measured territorial longitudinal strain (TLS) defined as the mean of peak systolic strain of the segments pertinent to the perfusion territories of each epicardial coronary arteries in a 17-segment LV model.
Results
mean LVEF was 53%. We found a significant relationship between GLS values and coronary artery disease extension: GLS -19,1 % ±5,7% in patients without significant coronary artery stenosis, -18,74% ±4,85% in patients with one coronary artery disease, -15,6% ±4,3% in patients with two coronary artery disease, -14,2% ±5,4% in patients with 3 coronary artery disease (p = 0,03).
We also found a correlation between territorial strain value and corresponding coronary artery stenosis.
TLS was significantly reduced in patients with significant coronary disease of the perfused territory for each artery (LAD TLS 15,1% ± 6,74 % vs -20,73± 4,47 p = 0,002; CX TLS -11,42 % ± 6,59 %,vs -17,06 ± 7,1, p = 0,0 05 , RCA -14,02 % ± 6,00 % vs-17,6 ± 5,21 p = 0,02).
At ROC analysis we identified a TLS value of -16,9 % to identify patients with significant stenosis of LAD (sensibility 58,3% and specificity 89,4%, AUC = 0,74, P < 0,001), TLS -18,2% for circumflex artery (sensibility 86,2% and specificity 78,9%, AUC = 0,78, P < 0,001) TLS -18% for right coronary (sensibility 73,9% and specificity 56,2%, AUC = 0,67, P = 0,027)
Conclusions
global and segmental strain measurement in patients with NSTEMI help to identify the presence and extension of significant coronary artery disease.
Value of global longitudinal strain by two dimensional speckle tracking echocardiography in predicting coronary artery disease severity
