Detection of Functionally Significant Coronary Artery Disease: Role of Regional Post Systolic Shortening.

BACKGROUND: The main goal of this manuscript was to evaluate the diagnostic value of the global and regional postsystolic shortening (PSS) parameters, assessed by two-dimensional (2D) speckle-tracking echocardiography, at rest and during dobutamine stress for the detection of functionally significant coronary artery stenoses in patients with moderate pretest probability of stable coronary artery disease (CAD). METHODS: Dobutamine stress echocardiography (DSE) and adenosine stress myocardial perfusion imaging by cardiac magnetic resonance (CMR-MPI) were performed on 83 patients with moderate pretest probability of stable CAD and left ventricle ejection fraction ≥55%. CAD was defined as ≥50% diameter stenoses on invasive coronary artery angiography (CAA) validated as hemodynamically significant by CMR-MPI. According to invasive CAA and CMR-MPI results, patients were divided into two groups: Nonpathologic CAD (-) group: 38 (45.8%) and pathologic CAD (+) group: 45 (54.2%). RESULTS: There were no significant differences in clinical characteristics, conventional 2D echocardiography between the two groups at rest and during low dobutamine dose. Regional postsystolic index (PSI) during recovery phase had the highest area under the receiver operating characteristic curve (AUC) (AUC 0.882, sensitivity 87%, specificity 92%) for the detection of functionally significant one-vessel disease. During high dobutamine dose, regional PSI had sensitivity 78% and specificity 81% (AUC 0.78) to detect significant CAD. Regional PSI remained the same tendency remains for the detection of multiple-vessel CAD. Other myocardial deformation parameters were less sensitive and specific during high dobutamine dose and recovery phase. CONCLUSIONS: PSS parameters showed to be sensitive and specific in detecting hemodynamically significant coronary artery stenosis in patients with stable CAD with moderate pretest probability. The study revealed that the assessment of regional PSI performed during recovery improves the diagnostic accuracy of DSE for the detection of functionally significant CAD.

Accuracy of three-dimensional systolic dyssynchrony and sphericity indexes for identifying early left ventricular remodeling after acute myocardial infarction.

OBJECTIVE: Left ventricle (LV) geometry and dyssynchrony are associated with LV remodeling after acute myocardial infarction (AMI). The aim of this prospective study was to assess the diagnostic value of new three-dimensional echocardiography (3DE) parameters [sphericity (SI) and systolic dyssynchrony indexes (SDI)] for the prediction of LV remodeling after AMI and to compare them with two-dimensional echocardiography (2DE) parameters. METHODS: 2DE and 3DE were performed in 75 patients with AMI within 3 days from the onset of MI and 6 months later. LV remodeling was defined as a ≥15% increase in the LV end-diastolic volume (EDV) at follow-up. 3D SI was calculated by dividing EDV by the volume of a sphere whose diameter was derived from the major end-diastolic LV long axis. SDI was considered as a standard deviation of the time from cardiac cycle onset to minimum systolic volume in 16 LV segments. RESULTS: LV remodeling was identified in 34 (45%) patients using the 2DE method and in 22 (29%) patients using the 3DE method. Evaluated 3DE parameters, such as EDV [area under the receiver operating characteristic (ROC) curve (AUC) 0.742, sensitivity 71%, specificity 79%], end-systolic volume (AUC 0.729, sensitivity 69%, specificity 78%), SDI (AUC 0.777, sensitivity 73%, specificity 77%), and SI, had significant prognostic value for LV remodeling. According to the AUC, the highest predictive value had 3D SI (AUC 0.957, sensitivity 90%, specificity 91%). CONCLUSION: 3DE parameters, especially 3D SI and SDI, play important roles in the prediction of LV remodeling after AMI and can be used in clinical practice.

Early and late diastolic strain rate vs global longitudinal strain at rest and during dobutamine stress for the assessment of significant coronary artery stenosis in patients with a moderate and high probability of coronary artery disease.

BACKGROUND: The aim of this prospective study was to assess the usefulness of global longitudinal strain (GLS), regional diastolic and systolic strain, strain rate (SR) parameters at rest and during dobutamine stress echocardiography for detecting significant coronary artery stenosis in patients with a moderate or high probability of coronary artery disease (CAD). METHODS: Dobutamine stress echocardiography and adenosine magnetic resonance imaging (AMRI) were performed on 127 patients with a moderate and high probability of CAD and left ventricle ejection fraction ≥55%. CAD was defined as ≥70% diameter stenosis on coronary angiography validated as hemodynamically significant by AMRI. Patients were grouped according to coronary angiography and AMRI results: CAD (-) n=67 (52.8%) vs CAD (+) n=60 (47.2%). RESULTS: There were no significant differences of clinical characteristics, conventional echocardiography, and deformation parameters between the two groups at rest except that GLS was higher in the CAD (-) group (-21.5±2.4% vs -16.2±2.1%, P=.00). GLS at high dobutamine doses had the highest area under the ROC curve (AUC) (AUC 0.955, sensitivity 94%, specificity 92%). Radial late diastolic SR at low doses performed best out of all diastolic parameters with an AUC of 0.789, sensitivity 76.7%, specificity 91.7%. Other deformation parameters including visual assessment were inferior. CONCLUSIONS: Global longitudinal strain is highly sensitive and specific in detecting hemodynamically significant coronary artery stenosis in moderate- to high-risk patients without known CAD. This is the first study showing that GLS is more sensitive and specific compared with early and late diastolic SR parameters or visual assessment in detecting CAD.