Usefulness of post-systolic index in facilitating stratification of risk in patients with intermediate- or low-risk non-ST-segment elevation acute coronary syndrome.

BACKGROUND: Although there is reportedly a usefulness of left ventricular global longitudinal strain (LV GLS) on 2D speckle-tracking echocardiography in excluding significant coronary artery disease (CAD) in suspected intermediate- or low-risk non-ST-segment elevation-acute coronary syndrome (NSTE-ACS), the efficacy of post-systolic index (PSI) in this context is yet unknown. Therefore, we explored the usefulness of PSI in facilitating stratification of risk in patients with intermediate- or low-risk NSTE-ACS. METHODS AND RESULTS: We assessed 50 consecutive patients suspected of intermediate- or low-risk NSTE-ACS, and finally analyzed 43 patients whose echocardiographic images were suitable for strain analysis. All patients underwent CAG. Among the 43 analyzed patients, 26 had CAD, and 21 underwent percutaneous coronary intervention (PCI). Patients with CAD had higher PSI (25% [20.8-40.3%] vs 15% [8.0-27.5%], P = 0.007). Receiver-operator characteristic curve analysis identified that a PSI of > 20% detected performance of PCI (sensitivity 80.7%, specificity 70.6%, area under curve [AUC] 0.72, 95% confidence interval [CI] 0.57-0.88). Moreover, the AUC obtained using the GRACE risk score was 0.57 (95% CI 0.39-0.75), and increased to 0.75 (95% CI 0.60-0.90) when PSI and LV GLS were added. Thus, the addition of PSI and LV GLS improved the classification of performance of PCI (net reclassification improvement [95%CI] 0.09 [0.0024-0.18], P = 0.04). CONCLUSIONS: Post-systolic index is a useful parameter that can facilitate stratification of risk in patients with intermediate- or low-risk NSTE-ACS. We recommend measuring PSI in routine clinical practice.

Multi-parametric speckle tracking analyses to characterize cardiac amyloidosis: a comparative study of systolic left ventricular longitudinal myocardial mechanics.

Cardiac amyloidosis (CAM), the most common cardiac storage disease is associated with significant changes in left-ventricular (LV) morphology and function. To gain particular insights into LV systolic longitudinal myocardial mechanics we investigated seven parameters derived by speckle-tracking-echocardiography (STE) in patients with confirmed CAM (n = 59). The results were compared with those of individuals with healthy heart (n = 150) and another primary myocardial disease with also thickened myocardium and severe diastolic and systolic LV-dysfunction (symptomatic LV-non-compaction-cardiomyopathy, LV-NC, n = 30). In addition to standard echocardiographical measures, the STE-derived data were evaluated and documented utilizing polar-diagrams to obtain overviews of longitudinal myocardial mechanics of the entire LV. Compared with healthy individuals, patients with CAM and LV-NC showed significantly reduced LV-ejection-fraction (EF), global longitudinal systolic peak-strain, strain-rate, and displacement. Pre-systolic stretch-index, post-systolic index, and the EF/global peak-longitudinal-strain-ratio (EF/S) were increased. In contrast to healthy-hearts and the LV-NC group only patients with CAM demonstrated significantly reduced time-to-peak systolic longitudinal strain and time-to-peak strain-rate. Although the level of the segmental values in longitudinal mechanics was significantly different between the groups, comparable intraventricular baso-apical parameter-gradients were found for systolic longitudinal peak-strain and strain-rate, pre-systolic-stretch-index, post-systolic-index, and peak systolic displacement. Compared to ATTR-amyloidosis (ATTR-CAM), patients with AL-amyloidosis (AL-CAM) demonstrated significantly lower end-diastolic and end-systolic LV-volumes, LV-mass-indices, relative apical strain, time-to-peak systolic longitudinal strain, and time-to-peak longitudinal strain-rate. CAM and LV-NC demonstrated altered myocardial mechanics with significantly different STE-derived echocardiographical parameters. ATTR-amyloidosis and AL-amyloidosis had at least significantly different time-to-peak strain, time-to-peak strain-rate and relative apical sparing values.

The effect of external counterpulsation on intrinsic myocardial function evaluated by speckle tracking echocardiography in refractory angina patients: a randomized controlled trial.

External Counterpulsation (ECP) is one of the therapeutic options in patients with refractory angina inadequately controlled by medical, interventional, or surgical therapy. The 2D Speckle Tracking Echocardiography (2D-STE) method is considered superior in assessing clinical improvement. We would like to evaluate any improvement of myocardial intrinsic function using 2D-STE in patients underwent standard ECP protocol (35 sessions). We conducted a double-blind randomized controlled trial. Patients with refractory angina who could not be revascularized conventionally were randomized into two groups: (1) the ECP group (300 mmHg) and (2) the Sham/control group (75 mmHg). ECP standard therapy was given for 35 sessions (1 h/day/session). The 2D-STE data, including longitudinal strain and post systolic index (PSI) were obtained before and after therapy. 43 subjects were analyzed, with 22 subjects in ECP group and 21 control subjects (Sham group). A homogenous baseline strain was found either globally (12.42 ± 4.55 vs 12.00 ± 4.92 [- %]; P = 0.774) or segmentally/regionally (12.63 (0.01-25.16) vs 12.43 (0.01-27.20) [- %]; P = 0.570). There was no statistically significant improvement between groups in the left ventricle longitudinal strain globally (P = 0.535) and segmentally/regionally (P = 0.434). PSI parameters showed improvement in the ECP group (P = 0.049), and segments with PSI ≥ 20% seemed to improve longitudinal strains in the ECP group after therapy (P = 0.042). In conclusion, 35 ECP therapy sessions did not improve either global or segmental/regional left ventricular mechanical function in patients with refractory angina. However, the mechanical function of myocardial segments with PSS tends to improve after ECP therapy.

Rapidly and Accurately Detecting Significant Coronary Artery Stenosis in Patients with Suspected Stable Coronary Artery Disease and Normal Segmental Wall Motion by Speckle Tracking Automated Functional Imaging.

This study was performed to explore the value of a machine with built-in speckle tracking automated functional imaging (AFI) in predicting the severity of coronary artery lesions in patients with suspected stable coronary artery disease (SCAD) with normal wall motion. One hundred forty-three consecutive patients with clinically suspected SCAD with normal wall motion were included. Multiple parameters, including global longitudinal peak strain, post-systolic index (PSI) and peak strain dispersion, were automatically analyzed with AFI. Territorial longitudinal strain (TLS) and territorial PSI (TPSI) were also calculated. Receiver operating characteristic curve analyses revealed that global longitudinal peak strain and PSI were superior to other parameters in detecting left main or three-vessel SCAD. A combination of TLS and TPSI could improve diagnostic performance in identifying significant stenotic left anterior descending and right coronary arteries. In conclusion, 2-dimensional speckle tracking AFI can rapidly provide multiple parameters for detecting significant coronary artery stenosis with high accuracy in patients suspected of having SCAD with normal wall motion.

Physiological left ventricular segmental myocardial mechanics: Multiparametric polar mapping to determine intraventricular gradients of myocardial dynamics.

OBJECTIVE: We investigated physiological systolic left ventricular (LV) myocardial mechanics and gradients to provide a database for later studies of diseased hearts. METHODS: The analyses were performed in 131 heart-healthy individuals and included seven parameters of myocardial mechanics using speckle tracking echocardiography (STE). RESULTS: Basal to apical and circumferentially significant physiological intraventricular parameter gradients of myocardial activity were determined. Global mean values and segmental ranges were peak systolic longitudinal strain -21.2 ± 3.3%, 95% confidence interval [CI] -21.8% to -20.6%), gradient (basal to apical) -16.0% to -26.7%; peak systolic longitudinal strain rate -1.24 ± 0.31%/s, 95% CI -1.29% to -1.19%/s, gradient (basal to apical) -0.91% to -1.61%/s; post-systolic index 2.6 ± 3.2%, 95% CI 3.15%-2.05%, gradient (basal/medial/apical) 7.0/1.2/2.4%; pre-systolic stretch index 1.3 ± 2.7%, 95% CI 1.77%-0.83%, gradient (basal/medial/apical) 6.5/0.2/1.3%; peak longitudinal displacement 12.2 ± 2.6 mm, 95% CI 12.6-11.8 mm, gradient (basal to apical) 21.0-3.4 mm; time-to-peak longitudinal strain 370 ± 43 ms, 95% CI 377-363 ms, gradient (basal to apical) 396-361 ms; and time-to-peak longitudinal strain rate 180 ± 47 ms, 95% CI 188-172 ms, gradient (basal to apical) 150-200 ms. CONCLUSION: This study generated a database of seven STE-derived parameters of physiological segmental and global myocardial LV mechanics. The resulting sets of three-dimensional intraventricular mappings of the entire LV provide physiological parameter gradients in baso-apical and circumferential direction by applying the 17-segment polar model. This will facilitate comparison of systolic myocardial activity of the healthy LV with diseased or otherwise altered (eg, sports) hearts.

Longitudinal strain of right ventricular free wall by 2-dimensional speckle-tracking echocardiography is useful for detecting pulmonary hypertension.

AIMS: Echocardiography is widely used for screening pulmonary hypertension (PH). More recently developed two-dimensional speckle-tracking echocardiography (2D-STE) can assess regional deformation of the myocardium and is useful for detecting left ventricular dysfunction. However, its usefulness to assess right ventricular (RV) dysfunction is not clear. Therefore, the aim of this study was to investigate the ability of peak systolic strain (PSS) and post-systolic strain index (PSI) at the RV free wall determined by 2D-STE to detect PH. MAIN METHODS: Thirty-six images (27 images from PH patients, nine from patients with connective tissue disease without PH) obtained by 2D-STE were analysed. We investigated the relationship between RV hemodynamics measured by right heart catheterization and PSS, PSI and other echocardiographic parameters reflecting RV overload including RV end-diastolic diameter (RVDd) and tricuspid valve regurgitant pressure gradient (TRPG). KEY FINDINGS: PSS, PSI, RVDd and TRPG were all correlated with mean pulmonary arterial pressure (MPAP) and pulmonary vascular resistance (PVR). Furthermore, when PSS and MPAP were measured twice, the change in PSS was correlated with the change in MPAP (r=0.633, p=0.037). Multivariate logistic regression analysis identified PSS as the only independent factor associated with MPAP ≥ 35mmHg [odds ratio (OR), 1.616; 95% confidence interval (CI) 1.017-2.567; p=0.042] and PVR ≥ 400dyn·s·cm(-5) (OR, 1.804; 95% CI 1.131-2.877; p=0.013). Furthermore, the optimal PSS cut-off value to detect an elevated MPAP and PVR was -20.75%, based on receiver operating characteristic curve analysis. SIGNIFICANCE: PSS of the RV free wall might serve as a useful non-invasive indicator of PH.