Influence of Myocardial Ischemia Extent on Left Ventricular Global Longitudinal Strain in Patients After ST-Segment Elevation Myocardial Infarction

Association of resting left ventricular global longitudinal strain with myocardial perfusion abnormalities evaluated by 13 N-ammonia positron emission tomography in patients with stable angina pectoris and normal left ventricular ejection fraction

AIMS

Little is known about whether resting left ventricular global longitudinal strain (GLS) impairment is associated with myocardial perfusion abnormalities evaluated using ¹³ N-ammonia positron emission tomography (¹³ N-NH₃ -PET)-myocardial perfusion imaging (MPI). This study aimed to investigate the correlation between resting GLS and myocardial perfusion parameters in patients with a normal left ventricular ejection fraction (LVEF). We evaluated whether resting GLS can predict myocardial perfusion abnormalities in these patients.

METHODS AND RESULTS

We selected 157 patients with suspected stable angina pectoris who underwent both ATP-stress NH₃ -PET-MPI and 2-dimentional speckle tracing echocardiography. All subjects had a preserved LVEF and no known history of myocardial infarction. Patients were stratified into Group N (normal perfusion; summed stress score [SSS], 0-3; n = 101), Group M (mildly to moderately abnormal perfusion; SSS, 4-11; n = 41), or Group S (severely abnormal perfusion; SSS, 12+; n = 15). GLS was more impaired as myocardial perfusion abnormality severity increased (-17.9 ± 2.9% for Group N, -16.8 ± 3.1% for Group M, and -14.2 ± 3.5% for Group S; p < .001). GLS was weakly but significantly correlated with SSS (R = .32, p < .001), summed difference score (R = .32, p < .001), and myocardial blood flow during stress (R = -0.27, p < .001). Multivariate logistic regression analysis showed that male sex, diabetes mellitus, systolic blood pressure, and GLS were independent predictors of myocardial perfusion abnormality defined as Groups M and S. Additionally, the area under the curve for GLS for detecting myocardial perfusion abnormality was .65, and the optimal cutoff value for GLS was -16.5%, with sensitivity and specificity of 59% and 66%, respectively.

CONCLUSION

In patients with suspected angina pectoris, resting GLS impairment despite a normal LVEF might aid the detection of hemodynamically significant coronary artery disease.

Clinical Utility of Three-Dimensional Speckle-Tracking Echocardiography in Heart Failure

Heart failure (HF) is an extremely major health problem with gradually increasing incidence in developed and developing countries. HF may lead to cardiac remodeling; thus, advanced imaging techniques are required to comprehensively evaluate cardiac mechanics. Recently, three-dimensional speckle-tracking echocardiography (3D-STE) has been developed as a novel imaging technology that is based on the three-dimensional speckle-tracking on the full volume three-dimensional datasets. Three-dimensional speckle-tracking echocardiography allows a more accurate evaluation of global and regional myocardial performance, assessment of cardiac mechanics, detection of subclinical cardiac dysfunction, and prediction of adverse clinical events in a variety of cardiovascular diseases. Therefore, this review summarizes the clinical usefulness of 3D-STE in patients with HF.

Pregnancy Complications Lead to Subclinical Maternal Heart Dysfunction—The Importance and Benefits of Follow-Up Using Speckle Tracking Echocardiography

Pregnancy complications such as gestational diabetes (GDM) and hypertensive disorders of pregnancy (HDP) are frequent and influence not only fetal outcomes but also the maternal cardiac function. GDM and HDP may act as a proxy for increased metabolic and cardiovascular risk later in life. Speckle tracking echocardiography (STE) is a relatively new imaging technique that provides more sensitive assessment than conventional echocardiography of the maternal cardiac function. Recent research suggests that STE can be used during pregnancy and postpartum as a useful method of early detection of subclinical maternal cardiac changes related to pregnancy complications, such as GDM and HDP, and as an indicator for future maternal cardiovascular disorders. The aim of this review was to underline the current value of STE in the follow-up protocol of high-risk pregnant women, as a mean for pre- and postpartum monitoring. A review of the literature was conducted in the PubMed database to select relevant articles regarding the association of STE changes and HDP or GDM in the prenatal and postpartum maternal evaluations. Both GDM and HDP are associated with subtle myocardial changes in shape, size and function; these preclinical cardiac changes, often missed by conventional evaluation, can be detected using STE. Left ventricular global circumferential strain might be an important predictor of maternal cardiovascular disorders and might help to define a high-risk group that requires regular monitoring later in life and timely intervention.

Copeptin levels predict left ventricular systolic function in STEMI patients: A 2D speckle tracking echocardiography-based prospective observational study

In the present study, we aimed to investigate whether copeptin values on admission are related to left ventricle (LV) systolic function and its improvement at 6 months in ST-segment elevation myocardial infarction (STEMI) patients.In this single-center, prospective observational study, we included 122 STEMI patients from January 2016 to November 2016. LV systolic functions in the form of global longitudinal strain (GLS) in addition to conventional echocardiography parameters were evaluated on admission and at 6-month. Serum copeptin levels were determined using an ultrasensitive immunofluorescence assay.The study population was divided into 2 groups according to median values of copeptin. GLS was significantly lower in patients with high copeptin levels compared to those with low copeptin levels at early stage and 6-month (-16% (16-16.5) vs -15% (15-15.5), P < .001 and -18% (18-19) vs -16% (16-16.25), P < .001, respectively). Copeptin values were negatively correlated with an early and 6-month GLS (r = -0.459 at early stage and r = -0.662 at 6-month). In addition, we observed that copeptin values were negatively correlated with the improvement of GLS at 6-month follow-up (r = -0.458, P < .001 and r = -0.357, P = .005, respectively).Serum copeptin levels in STEMI patients at the time of admission may predict early and 6-month LV systolic function assessed by two-dimensional GLS. To the best of our knowledge, this study is the first to specifically address the relationship between copeptin values and GLS in STEMI patients.

Improvement of left ventricular function assessment by global longitudinal strain after successful percutaneous coronary intervention for chronic total occlusion

The benefit of revascularization of chronic total occlusion (CTO) in percutaneous coronary intervention (PCI) is controversial. On the other hand, left ventricular (LV) global longitudinal strain (GLS) is a more sensitive marker of LV myocardial ischemia and LV function than LV ejection fraction (EF). The purpose of this study was to investigate the impact of revascularization of CTO on LV function using LV GLS. A total of 70 consecutive patients (65.1±8.9 years, 59 males, LVEF 51.0±12.0%) with CTO who had a positive functional ischemia and underwent PCI, were included in this study. Echocardiography was performed before and 9 months after the procedure with conventional assessment including LV end-diastolic and end-systolic volume (LVEDV, LVESV), LVEF, and with 2DSTE analysis of GLS. Successful PCI was obtained in 60 patients (86%). There were no stent thromboses during follow-up. GLS showed a significant improvement 9 months after successful PCI (pre-PCI -12.4±4.1% vs. post-PCI -14.5±4.1%, P< 0.01), whereas in failed PCI group that did not change significantly (pre-PCI -13.2±4.2% vs. post-PCI -14.0±4.7%, P = 0.64). LVEF, LVEDV and LVESV did not change significantly during follow-up in both successful and failed groups. Successful PCI for CTO improved LV function, assessed by LV GLS.

Effect of Guideline-Based Therapy on Left Ventricular Systolic Function Recovery After ST-Segment Elevation Myocardial Infarction

Little is known about the proportion of ST-segment elevation myocardial infarction (STEMI) patients treated with primary percutaneous coronary intervention, who have reduced left ventricular ejection fraction (LVEF) within 48 hours (baseline) of admission and exhibit LVEF recovery under optimal guideline-based medical treatment. Therefore, the present study evaluates the evolution of LVEF in patients after STEMI and under guideline-based medical therapy. In 2,853 STEMI patients treated with primary percutaneous coronary intervention, echocardiography was performed at baseline and at 6 months follow-up. Patients with previous myocardial infarction, reinfarction, coronary artery bypass grafting or incomplete echocardiographic data at 6 months follow-up were excluded. Reduced LVEF at baseline was defined as <40%. LVEF recovery was defined as LVEF >50% at 6 months follow-up. The prevalence of LVEF <40% at baseline was 13% (n = 371 patients; mean age 60 [range 33 to 88] years; 76% men). At follow-up, 31% of patients remained with a LVEF <40%, 30% showed a LVEF between 41% and 49% and in 39% of patients LVEF improved to >50%. There were no differences in usage of guideline-based medications at discharge across groups. On multivariable analysis, peak troponin T levels (odds ratio [OR] 0.895; p < 0.001), baseline LVEF (OR 1.069; p = 0.023) and absence of significant mitral regurgitation (OR 0.376; p = 0.018) were independently associated with LV recovery at follow-up. In conclusion, the prevalence of LVEF <40% is low. With optimal medical therapy, LVEF normalizes in 39% of patients. Smaller enzymatic infarct size, baseline LVEF and absence of mitral regurgitation were independently associated with LVEF recovery at follow-up.

Attenuation correction in myocardial perfusion imaging affects the assessment of infarct size in women with previous inferior infarct

BACKGROUND

Myocardial perfusion imaging is a well-established diagnostic tool in patients with known or suspected coronary artery disease. Numerous clinical trials have shown that attenuation correction (AC) in single photon emission computed tomography (SPECT) improves the diagnostic accuracy of myocardial perfusion imaging over non-AC SPECT, differentiating between scar and attenuation artifacts. We have previously shown that attenuation artifacts produce an overestimation of the size of inferior infarcts in the male population. It is assumed that women are less affected by inferior attenuation artifacts than men.

PURPOSE

The aim of this study is to evaluate the role of AC in the assessment of infarct size in female patients with a history of myocardial inferior infarct.

PATIENTS AND METHODS

We studied a population of 66 consecutive women, with a history of previous inferior myocardial infarct, by SPECT/computed tomography (CT) with 370+370 MBq of technetium-99m labeled compounds by a 2-day stress-rest protocol. Both AC and uncorrected gated-SPECT/CT studies were reconstructed after scatter and motion correction by ordered-subset expectation maximization iterative reconstruction and resolution recovery. The coregistration of the transmission and emission scans was verified for all patients; any misalignment was realigned manually. Uncorrected and corrected SPECT images were analyzed by software QPS/QGS package using a 17-segment model. For each segment, perfusion and wall motion were quantified using a five-point score according to the American Society of Nuclear Cardiology guidelines. Summed stress, summed rest score (SRS), and summed difference score of the inferior left ventricle wall (inferior, inferoseptal, inferolateral, and apical inferior segments) were calculated. A linear correlation was used to assess the relationship between perfusion and the regional wall motion score as determined by uncorrected gated-SPECT.

RESULTS

The results of quantitative analysis of non-AC and CT-AC SPECT images, respectively, were as follows: summed stress score: 9.47±5.01 and 6.58±4.77% (P<0.001); SRS was 6.05±5.02 and 4.14±4.12% (P<0.001); the summed difference score was 2.92±2.74 and 2.52±2.63% (P=NS), respectively. The correlation between corrected and uncorrected SRS and the regional summed wall motion score of the same segment was R=0.31 versus R=0.34.

CONCLUSION

In the female population, like in men, attenuation artifacts affect the calculation of the infarct size of the inferior wall, with overestimation of the infarct size in uncorrected images. The AC regional perfusion score (SRS) better correlates with the regional wall motion score of the inferior wall in women with previous inferior infarct.

Myocyte membrane and microdomain modifications in diabetes: determinants of ischemic tolerance and cardioprotection

Cardiovascular disease, predominantly ischemic heart disease (IHD), is the leading cause of death in diabetes mellitus (DM). In addition to eliciting cardiomyopathy, DM induces a ‘wicked triumvirate’: (i) increasing the risk and incidence of IHD and myocardial ischemia; (ii) decreasing myocardial tolerance to ischemia–reperfusion (I–R) injury; and (iii) inhibiting or eliminating responses to cardioprotective stimuli. Changes in ischemic tolerance and cardioprotective signaling may contribute to substantially higher mortality and morbidity following ischemic insult in DM patients. Among the diverse mechanisms implicated in diabetic impairment of ischemic tolerance and cardioprotection, changes in sarcolemmal makeup may play an overarching role and are considered in detail in the current review. Observations predominantly in animal models reveal DM-dependent changes in membrane lipid composition (cholesterol and triglyceride accumulation, fatty acid saturation vs. reduced desaturation, phospholipid remodeling) that contribute to modulation of caveolar domains, gap junctions and T-tubules. These modifications influence sarcolemmal biophysical properties, receptor and phospholipid signaling, ion channel and transporter functions, contributing to contractile and electrophysiological dysfunction, cardiomyopathy, ischemic intolerance and suppression of protective signaling. A better understanding of these sarcolemmal abnormalities in types I and II DM (T1DM, T2DM) can inform approaches to limiting cardiomyopathy, associated IHD and their consequences. Key knowledge gaps include details of sarcolemmal changes in models of T2DM, temporal patterns of lipid, microdomain and T-tubule changes during disease development, and the precise impacts of these diverse sarcolemmal modifications. Importantly, exercise, dietary, pharmacological and gene approaches have potential for improving sarcolemmal makeup, and thus myocyte function and stress-resistance in this ubiquitous metabolic disorder.

ATP5J and ATP5H Proactive Expression Correlates with Cardiomyocyte Mitochondrial Dysfunction Induced by Fluoride

To investigate the effect of excessive fluoride on the mitochondrial function of cardiomyocytes, 20 healthy male mice were randomly divided into 2 groups of 10, as follows: control group (animals were provided with distilled water) and fluoride group (animals were provided with 150 mg/L F^- drinking water). Ultrastructure and pathological morphological changes of myocardial tissue were observed under the transmission electron and light microscopes, respectively. The content of hydrolysis ATP enzyme was observed by ATP enzyme staining. The expression levels of ATP5J and ATP5H were measured by Western blot and quantitative real-time PCR. The morphology and ultrastructure of cardiomyocytes mitochondrial were seriously damaged by fluoride, including the following: concentration of cardiomyocytes and inflammatory infiltration, vague myofilaments, and mitochondrial ridge. The damage of mitochondrial structure was accompanied by the significant decrease in the content of ATP enzyme for ATP hydrolysis in the fluoride group. ATP5J and ATP5H expressions were significantly increased in the fluoride group. Thus, fluoride induced the mitochondrial dysfunction in cardiomyocytes by damaging the structure of mitochondrial and interfering with the synthesis of ATP. The proactive ATP5J and ATP5H expression levels were a good response to the mitochondrial dysfunction in cardiomyocytes.

Comparison of Left Ventricular Function and Myocardial Infarct Size Determined by 2-Dimensional Speckle Tracking Echocardiography in Patients With and Without Chronic Obstructive Pulmonary Disease After ST-Segment Elevation Myocardial Infarction

Patients with chronic obstructive pulmonary disease (COPD) have a high risk of mortality after acute ST-segment elevation myocardial infarction (STEMI). We compared STEMI patients with versus without COPD in terms of infarct size and left ventricular (LV) systolic function using advanced 2-dimensional speckle tracking echocardiography. Of 1,750 patients with STEMI (mean age 61 ± 12 years, 76% male), 133 (7.6%) had COPD. With transthoracic echocardiography, left ventricular ejection fraction (LVEF) and wall motion score index were measured. Infarct size was assessed using biomarkers (creatine kinase and troponin T). LV global longitudinal strain (GLS), reflecting active LV myocardial deformation, was measured with 2-dimensional speckle tracking echocardiography to estimate LV systolic function and infarct size. STEMI patients with COPD were significantly older, more likely to be former smokers, and had worse renal function compared with patients without COPD. There were no differences in infarct size based on peak levels of creatine kinase (1315 [613 to 2181] vs 1477 [682 to 3047] U/l, p = 0.106) and troponin T (3.3 [1.4 to 7.3] vs 3.9 [1.5 to 7.8] µg/l, p = 0.489). Left ventricular ejection fraction (46% vs 47%, p = 0.591) and wall motion score index (1.38 [1.25 to 1.66] vs 1.38 [1.19 to 1.69], p = 0.690) were comparable. In contrast, LV GLS was significantly more impaired in patients with COPD compared with patients without COPD (-13.9 ± 3.0% vs -14.7 ± 3.9%, p = 0.034). In conclusion, despite comparable myocardial infarct size and LV systolic function as assessed with biomarkers and conventional echocardiography, patients with COPD exhibit more impaired LV GLS on advanced echocardiography than patients without COPD, suggesting a greater functional impairment at an early stage after STEMI.