Three-dimensional transesophageal echocardiographic study of aortic-mitral valve coupling after coronary artery bypass grafting.

AIMS: To observe the geometric changes in aortic-mitral valve coupling (AMC) on three-dimensional transesophageal echocardiography and the factors leading to decreased mitral regurgitation (MR) after coronary artery bypass grafting (CABG). METHODS AND RESULTS: This study included 23 patients undergoing CABG for coronary artery disease. Fifteen patients with moderate to severe MR were separately analyzed to determine whether the severity of MR influences the geometric change in AMC. Echocardiographic examinations were performed pre- and post-CABG, and the studied parameters were obtained using Siemens Auto Valve Analysis software. The effective mitral regurgitant orifice area, left ventricular ejection fraction (LVEF), end-diastolic volume (EDV), and end-systolic volume (ESV) were measured pre- and post-CABG using Philips QLAB software. Ischemic MR, EDV, and ESV significantly decreased (all P < 0.05) and LVEF significantly improved (P < 0.05) after CABG. There were no significant differences between the pre- and post-CABG mitral valve (MV) parameters, aortic valve parameters, aortic-mitral annular angle, or centroid distance (all P > 0.05). Patients with moderate to severe MR exhibited the same results. CONCLUSION: The results of this study show that CABG does not cause an acute change in the geometry of AMC. Improved left ventricular function might increase the closing force of the MV, leading to decreased MR after CABG alone. MR significantly improved after CABG alone without MV treatment in the present study. This result may help to guide surgeons in choosing the optimal surgical methods for individual patients.

Assessment of Left Ventricular Global Myocardial Work in Patients With Different Degrees of Coronary Artery Stenosis by Pressure-Strain Loops Analysis.

Global myocardial work (MW) analysis by pressure-strain loops (PSL) allows the non-invasive assessment of left ventricular (LV) function. We aimed to investigate the relationship between LV global MW and the degree of coronary artery stenosis in suspected coronary artery disease (CAD) patients with normal LV ejection fraction and regional wall motion. A total of 164 suspected CAD patients were divided into four groups according to coronary artery angiography. The results showed that global work efficiency (GWE) as the most significant predictor in all MW parameters had the optimal cut-off value of 94.5% for detecting moderate stenosis, and the sensitivity and specificity was 89.7% and 85.8%, respectively. A cut-off value of 94.0% for GWE was the most significant predictor of severe stenosis, and the sensitivity and specificity was 81.4% and 76.1%, respectively. In conclusion, LV global MW is a sensitive tool in detecting the degree of coronary artery stenosis and a potential valuable method to provide early diagnosis for CAD patients.

Prognostic potential of layer-specific global longitudinal strain in patients with non-ST-segment elevated acute coronary syndrome and preserved left ventricular ejection fraction.

This study sought to investigate the prognostic potential of layer-specific global longitudinal strain (GLS) in predicting cardiac events among non-ST-segment elevated acute coronary syndrome (NSTE-ACS) patients with preserved LVEF. In this prospective study, we enrolled 160 consecutive NSTE-ACS patients with preserved LVEF (≥ 50%) who underwent successful percutaneous coronary intervention (PCI). Transthoracic two-dimensional echocardiography examinations were performed within 48 h of admission (before PCI). Cardiac events were defined as all-cause death, re-infarction, and hospitalization for heart failure. During a median follow-up of 30.2 months, 23 patients (14.4%) developed cardiac events. GLS for all three myocardial layers were reduced in patients with adverse outcome (all P < 0.001). Yet GLSendo (area under curves = 0.85) and GLSmid (area under curves = 0.83) showed relatively higher predictive power than GLSepi when identifying patients with cardiac events. The best cut-off value of GLSendo was - 20.8%, with a diagnostic sensitivity and specificity of 87% and 71% respectively. A significant increase in the risk of cardiac events development was shown among patients with impaired layer GLS (log-rank test, P < 0.001). In conclusion, NSTE-ACS patients with preserved LVEF, layer GLS assessed before PCI all had good abilities to predict cardiac events, which might provide more prognostic information against conventional echocardiographic risk factors.

Mesenchymal Stromal Cells from Patients with Cyanotic Congenital Heart Disease are Optimal Candidate for Cardiac Tissue Engineering.

Engineered heart tissues (EHTs) are regarded as being the most promising alternative to synthetic materials, and autologous mesenchymal stem cells (MSCs) are widely used as seeding cells. However, few studies have evaluated the feasibility of using MSCs from patients with cyanotic congenital heart disease (C-CHD) as seeding cells for EHTs, in comparison with cells from patients of acyanotic congenital heart disease (A-CHD). In the present study, we cultured MSCs from A-CHD and C-CHD patients in normoxia or hypoxia conditions, and compared their pro-angiogenic, anti-apoptotic and inflammation-modulatory potentials. In vivo, we seeded the cells into collagen patches conjugated with, or without, proangiogenic cytokines, which were used to repair the right ventricular outflow tract (RVOT) of rats. The in vitro results showed that C-CHD MSCs expressed higher levels of VEGFA and VEGFR2, and secreted more pro-angiogenic and anti-inflammatory cytokines under hypoxic conditions. On the other hand, apoptosis-related genes from C-CHD MSCs were modulated adaptably, converting these cells into an anti-apoptotic phenotype. In vivo studies demonstrated that in 4 weeks after RVOT reconstruction, cytokine-immobilized patches seeded with C-CHD MSCs exhibited preserved morphology, prolonged cell survival and enhanced angiogenesis compared to A-CHD MSCs. C-CHD MSCs that undergo "naturally hypoxic precondition" present a better cell source for EHTs, which would provide a promising individualized biomaterial for C-CHD patients.

Assessment of global and regional left ventricular function after surgical revascularization in patients with coronary artery disease by real-time triplane echocardiography.

OBJECTIVE: The purpose of this study was to evaluate the capability of real-time triplane echocardiography (RT3PE) for monitoring global and regional systolic function of the left ventricle (LV) after surgical revascularization and for evaluating the effect of surgery and predicting restenosis. METHODS: Forty-nine patients underwent RT3PE before and at 10 days and 1, 3, and 6 months after coronary artery bypass grafting (CABG). The global systolic function of the LV was assessed with the parameters of end-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF), and stroke volume (SV). The regional myocardial deformation was detected by triplane strain rate imaging. Recovery of myocardial function after surgery and the correlation between global and regional function were investigated. RESULTS: In 41 of the 49 patients, the EDV and ESV decreased, and the EF and SV increased gradually and showed statistical significance at 3 and 6 months after surgery (P < .05; P < .01). The systolic strain rate (SR(sys)) and systolic strain (S(sys)) increased, and the postsystolic strain index (PSI) decreased progressively after CABG, with significant changes in almost all studied segments at 6 months (P < .05; P < .01). In addition, recovery of the SR(sys), S(sys), and PSI at each follow-up stage after surgery correlated well with EF improvement, with a positive correlation between the SR(sys), S(sys), and EF and a negative correlation between the PSI and EF. Restenosis was suspected in the other 8 patients. The sensitivity, specificity, and accuracy of RT3PE to predict restenosis were 75.00%, 89.47%, and 85.19%, respectively. CONCLUSIONS: Real-time triplane echocardiography can be used to quantitatively assess global and regional myocardial function. It may represent a new, powerful method to monitor improvement of myocardial function after CABG and to predict restenosis.

Comparison of adipose­ and bone marrow­derived stem cells in protecting against ox­LDL­induced inflammation in M1­macrophage­derived foam cells.

Adipose­derived stem cells (ADSCs) and bone marrow­derived stem cells (BMSCs) are considered to be prospective sources of mesenchymal stromal cells (MSCs), that can be used in cell therapy for atherosclerosis. The present study investigated whether ADSCs co­cultured with M1 foam macrophages via treatment with oxidized low­density lipoprotein (ox­LDL) would lead to similar or improved anti­inflammatory effects compared with BMSCs. ADSCs, peripheral blood monocytes, BMSCs and ox­LDL were isolated from ten coronary heart disease (CHD) patients. After three passages, the supernatants of the ADSCs and BMSCs were collected and systematically analysed by liquid chromatography­quadrupole time­of­flight­mass spectrometry (6530; Agilent Technologies, Inc., Santa Clara, CA, USA). Cis­9, trans­11 was deemed to be responsible for the potential differences in the metabolic characteristics of ADSCs and BMSCs. These peripheral blood monocytes were characterized using flow cytometry. Following peripheral blood monocytes differentiation into M1 macrophages, the formation of M1 foam macrophages was achieved through treatment with ox­LDL. Overall, 2x106 ADSCs, BMSCs or BMSCs+cis­9, trans­11 were co­cultured with M1 foam macrophages. Anti­inflammatory capability, phagocytic activity, anti­apoptotic capability and cell viability assays were compared among these groups. It was demonstrated that the accumulation of lipid droplets decreased following ADSCs, BMSCs or BMSCs+cis­9, trans­11 treatment in M1 macrophages derived from foam cells. Consistently, ADSCs exhibited great advantageous anti­inflammatory capabilities, phagocytic activity, anti­apoptotic capability activity and cell viability over BMSCs or BMSCs+cis­9, trans­11. Additionally, BMSCs+cis­9, trans­11 also demonstrated marked improvement in anti­inflammatory capability, phagocytic activity, anti­apoptotic capability activity and cell viability in comparison with BMSCs. The present results indicated that ADSCs would be more appropriate for transplantation to treat atherosclerosis than BMSCs alone or BMSCs+cis­9, trans­11. This may be an important mechanism to regulate macrophage immune function.

Improved Left Ventricular Aneurysm Repair with Cell- and Cytokine-Seeded Collagen Patches.

BACKGROUND: Engineered heart tissues (EHTs) present a promising alternative to current materials for surgical ventricular restoration (SVR); however, the clinical application remains limited by inadequate vascularization postimplantation. Moreover, a suitable and economic animal model for primary screening is another important issue. METHODS: Recently, we used 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride chemistry (EDC) to initiate a strengthened, cytokine-conjugated collagenous platform with a controlled degradation speed. In vitro, the biomaterial exhibited an enhanced mechanical strength maintaining a porous ultrastructure, and the constant release of cytokines promoted the proliferation of seeded human mesenchymal stem cells (hMSCs). In vivo, with the hMSC-seeded, cytokine-immobilized patch (MSCs + GF patch), we performed modified SVR for rats with left ventricular aneurysm postmyocardial infarction (MI). Overall, the rats that underwent modified SVR lost less blood and had lower mortality. After 4 weeks, the rats repaired with this cell-seeded, cytokine-immobilized patch presented preserved cardiac function, beneficial morphology, enhanced cell infiltration, and functional vessel formation compared with the cytokine-free (MSC patch), cell-free (GF patch), or blank controls (EDC patch). Furthermore, the degradable period of the collagen patch in vivo extended up to 3 months after EDC treatment. CONCLUSIONS: EDC may substantially modify collagen scaffold and provide a promising and practical biomaterial for SVR.

Tissue synchronization imaging of myocardial dyssynchronicity of the left ventricle in patients with coronary artery disease.

OBJECTIVE: The purpose of this study was to evaluate regional myocardial dyssynchronicity and velocity of the left ventricle in patients with coronary artery disease. METHODS: Tissue synchronization imaging analysis of the time to peak velocity (Tp) and peak velocity (Vp) of left ventricular longitudinal myocardial segments was performed for 60 patients with coronary artery disease and 40 healthy subjects. RESULTS: Tissue synchronization imaging revealed synchronous myocardia in the control group and disturbed myocardial synchrony in patients, with greater dyssynchrony than in the control group (P < .005). Compared with the control group, patients showed a higher Tp of the left ventricular anterior wall and interventricular septum (P < .001). The apex-to-base gradient of tissue velocity was absent in patients. The mean Vp of all segments except the apical segment of the interventricular septum in patients was decreased significantly (P < .05). CONCLUSIONS: Tissue synchronization imaging is a novel and noninvasive technique for quantitatively assessing regional myocardial Tp and Vp and can directly and quickly determine ischemia or infarction in myocardial segments.