R-R' interval in the left bundle branch block predicts long-term outcomes after cardiac resynchronization therapy by estimating greater mechanical dyssynchrony and viable myocardium.

BACKGROUND: Typical left bundle branch block (LBBB) shows 2 peaks of the R wave, which reflect activation reaching the interventricular septum (R) and posterolateral wall (R') sequentially. OBJECTIVE: The purpose of this study was to investigate the relationship among R-R' interval (RR'), mechanical dyssynchrony, extent of viable myocardium, and long-term outcomes in cardiac resynchronization therapy (CRT) candidates. METHODS: The study enrolled 49 patients (34 men; mean age: 69 ± 11 years) with LBBB who received CRT. The LBBB definition used requires the presence of mid-QRS notching in leads V1, V2, V5, V6, I, and aVL. Baseline evaluations were QRS duration (QRSd) and RR' measured from the 12-lead electrocardiogram; eyeball dyssynchrony (apical rocking and septal flash) and opposing-wall delay by speckle tracking from echocardiography, and extent of viable myocardium assessed by thallium-201 single-photon emission computed tomography. Primary outcomes included the combination of all-cause death and heart failure-related hospitalization. RESULTS: RR' predicted volumetric response better than QRSd (area under the curve 0.73 vs 0.67, respectively). The long RR' group (≥48 ms) revealed more frequent eyeball dyssynchrony and significantly greater radial (SL) and circumferential dyssynchrony (AP and SL) and %viable segment than the short RR' group. In multivariate regression analysis, only RR' ≥48 ms was independently associated with higher event-free survival rates following CRT (hazard ratio 0.21; P = .014). CONCLUSION: These findings suggest that RR' in complete LBBB was associated with mechanical dyssynchrony, extent of viable myocardium, and long-term outcomes following CRT.

Role of Antiplatelet Therapy in Patients with Severe Coronary Artery Disease Undergoing Coronary Artery Endarterectomy within Coronary Artery Bypass Surgery.

Background-Coronary endarterectomy (CEA) has been introduced to allow revascularization in end-stage coronary artery disease (CAD). After CEA, the injured remnants of the vessel's media could result in fast neo intimal tissue ingrowth, which require an anti-proliferation agent (antiplatelet therapy (APT). We aimed to review outcomes of patients undergoing CEA within bypass surgery who received either single-APT (SAPT) or dual-APT (DAPT). Methods-We retrospectively evaluated 353 consecutive patients undergoing CEA within isolated coronary artery bypass grafting (CABG) in the period 01/2000-07/2019. After surgery, patients received either SAPT (n = 153), or DAPT (n = 200) for six months then lifelong SAPT. Endpoints included early, late survival, and freedom from major-adverse-cardiac and cerebrovascular events (MACCE), which were defined as incidence of stroke, myocardial infarction, need for coronary intervention (PCI or CABG) or death for any cause. Results-Patients' mean age was 67 ± 9.3 years; they were predominantly male 88.1%. Both DAPT- and SAPT-groups had the same extent of CAD (mean SYNTAX-Score-II: 34.1 ± 11.6 vs. 34.4 ± 17.2, p = 0.91). Postoperatively, no difference between DAPT- and SAPT-groups was reported in the incidence of low-cardiac-output syndrome (5% vs. 9.8%, p = 0.16), revision for bleeding (5% vs. 6.5% p = 0.64), 30-day mortality (4.5% vs. 5.2%, p = 0.8) or MACCE (7.5% vs. 11.8%, p = 0.19). Imaging follow-up reported significantly higher CEA and total grafts patency (90% vs. 81.5% and 95% vs. 81%, p = 0.017) in DAPT patients. Late outcomes within 97.4 ± 67.4 months show lower incidence of overall mortality (19 vs. 51%, p < 0.001) and MACCE (24.5 vs. 58.2%, p < 0.001) in the DAPT patients when compared with SAPT patients. Conclusions-Coronary endarterectomy allows revascularization in end-stage CAD when the myocardium is still viable. The use of dual APT after CEA for at least six months seems to improve mid-to-long-term patency rates and survival, and reduced the incidence of major adverse cardiac and cerebrovascular events.

[The myocardial infarction size measuring using modern methods].

An accurate quantitative assessment of myocardium necrosis area and the viable zone (stunned and hibernating) in patients with myocardial infarction is crucial for the preoperative patient selection and predicting the cardiac surgery effectiveness. Currently, researchers and clinicians are most interested in the problem of determining the viable myocardium zone. However, only the necrosis zone area directly correlates with the patients prognosis and determines the heart pathological remodeling processes. In the distant period, the data obtained can be used to predict the post-infarction period course or for analysis the relationship of the necrosis zone with arrhythmogenesis, and a number of other indicators. Thus, the necrosis zone and the viable myocardium zone are two parameters that need to be monitored in dynamics in all patients after myocardial infarction. The most accurate and reproducible method for determining the necrosis area is contrast magnetic resonance imaging of the heart, however, this technique is still inaccessible in most hospitals. In this regard, it remains relevant to estimate the necrotic myocardium area by ubiquitous non-invasive methods such as electrocardiography and echocardiography.

[Association between brain glucose metabolism and cardiac dysfunction in patients with ischemic heart disease undergoing (18)F-FDG PET/CT imaging].

Objective: To evaluate the relationship between the brain glucose metabolism and left ventricular function parameters, and to explore the cerebral glucose metabolism reduction regions in patients with ischemic heart disease (IHD). Methods: A total of 110 consecutive IHD patients who underwent gated (99)Tc(m)-sestamibi (MIBI) SPECT/CT myocardial perfusion imaging, gated (18)F-fluorodeoxyglucose (FDG) PET/CT myocardial and brain glucose metabolic imaging within three days in Beijing Anzhen Hospital from April 2016 to October 2017, were enrolled in this study. Left ventricular functional parameters of SPECT/CT and PET/CT including end-diastolic volume (EDV), end-systolic volume (ESV) and left ventricular ejection fraction (LVEF) were analyzed by QGS software. Viable myocardium and myocardial infarction region were determined by 17-segment and 5 score system, and the ratio of viable myocardium and scar myocardium was calculated. According to the range of viable myocardium, the patients were divided into viable myocardium<10% group (n=44), viable myocardium 10%-<20% group (n=36) and viable myocardium≥20% group (n=30). Pearson correlation analysis was used to analyze the correlation between the range of viable myocardium and scar myocardium and the level of cerebral glucose metabolism. Brain glucose metabolism determined by the mean of standardized uptake value (SUV(mean)) was analyzed by SPM. The ratio of SUV(mean) in whole brain and SUV(mean) in cerebellum were calculated, namely taget/background ratio (TBR). Differences in cerebral glucose metabolism among various groups were analyzed by SPM. Results: There were 101 males, and age was (57±10) years in this cohort. The extent of viable myocardium and the extent of scar, LVEF evaluated by SPECT/CT and PET/CT were significantly correlated with TBR (r=0.280, r=-0.329, r=0.188, r=0.215 respectively,all P<0.05). TBR value was significantly lower in viable myocardium<10% group, compared with viable myocardium 10%-<20% group (1.25±0.97 vs. 1.32±0.17, P<0.05) and viable myocardium≥20% group (1.25±0.97 vs. 1.34±0.16, P<0.05). Furthermore, in comparison with viable myocardium≥20% group, the hypo-metabolic regions of viable myocardium<10% group were located in the precuneus, frontal lobe, postcentral gyrus, parietal lobe, temporal lobe, and so on. Conclusions: There is a correlation between impaired left ventricular function and brain glucose metabolism in IHD patients. In IHD patients with low myocardial viability, the level of glucose metabolism in the whole brain is decreased, especially in the brain functional areas related to cognitive function.

Ischaemic cardiomyopathy. Pathophysiological insights, diagnostic management and the roles of revascularisation and device treatment. Gaps and dilemmas in the era of advanced technology.

Ischaemic cardiomyopathy (ICM) represents an important cardiovascular condition associated with substantially increased morbidity and mortality. It is characterised from a broad spectrum of clinical manifestations and pathophysiological substrates and its diagnosis is based on the demonstration of significant left ventricular dysfunction in the context of significant epicardial coronary artery disease. Contemporary management aims at improving prognosis through evidence-based pharmacotherapy and device therapy, where indicated. Whilst the beneficial role of revascularisation remains clear in patients with strong indications such as those with symptoms and/or acute coronary syndromes, for those patients that are asymptomatic and suffer from stable ischaemic heart disease the impact of revascularisation on hard outcomes remains less well defined and currently its adoption is hampered by the lack of robust randomised data. The aim of this review is therefore to provide a constructive appraisal on the pathophysiology of ICM, the role of the various non-invasive imaging techniques in the diagnosis of ICM and the differentiation between viable and non-viable myocardium and finally discourse the potential role of revascularisation and contemporary device therapy in the management of patients with ICM.

Procedures for chronic total occlusion: when are they recommended and when not.

Coronary chronic total occlusion (CTO) produces an important clinical problem, often treated with medical therapy or coronary artery bypass grafting. Recent clinical studies, both registries and randomized trials, demonstrated that percutaneous coronary interventions (PCI), could provide a valid therapeutic option. Nonetheless, significant reduction in all-cause mortality, cardiac mortality, myocardial infarction, MACE, and MACCE has not been demonstrated in the subgroups analysis of randomized trials. These analyses suggest that PCI for CTO should be reserved for patients with angina or with large areas of the myocardium with reversible ischaemia. Large randomized studies should search for a personalized approach, considering the risks and complexity of PCI in CTO, which should mainly consider the extension of the ischaemia and the viability of the myocardium.

Association between brain glucose metabolism and cardiac dysfunction in patients with ischemic heart disease undergoing (18)F-FDG PET/CT imaging / 中华心血管病杂志

Objective: To evaluate the relationship between the brain glucose metabolism and left ventricular function parameters, and to explore the cerebral glucose metabolism reduction regions in patients with ischemic heart disease (IHD). Methods: A total of 110 consecutive IHD patients who underwent gated (99)Tc(m)-sestamibi (MIBI) SPECT/CT myocardial perfusion imaging, gated (18)F-fluorodeoxyglucose (FDG) PET/CT myocardial and brain glucose metabolic imaging within three days in Beijing Anzhen Hospital from April 2016 to October 2017, were enrolled in this study. Left ventricular functional parameters of SPECT/CT and PET/CT including end-diastolic volume (EDV), end-systolic volume (ESV) and left ventricular ejection fraction (LVEF) were analyzed by QGS software. Viable myocardium and myocardial infarction region were determined by 17-segment and 5 score system, and the ratio of viable myocardium and scar myocardium was calculated. According to the range of viable myocardium, the patients were divided into viable myocardium<10% group (n=44), viable myocardium 10%-<20% group (n=36) and viable myocardium≥20% group (n=30). Pearson correlation analysis was used to analyze the correlation between the range of viable myocardium and scar myocardium and the level of cerebral glucose metabolism. Brain glucose metabolism determined by the mean of standardized uptake value (SUV(mean)) was analyzed by SPM. The ratio of SUV(mean) in whole brain and SUV(mean) in cerebellum were calculated, namely taget/background ratio (TBR). Differences in cerebral glucose metabolism among various groups were analyzed by SPM. Results: There were 101 males, and age was (57±10) years in this cohort. The extent of viable myocardium and the extent of scar, LVEF evaluated by SPECT/CT and PET/CT were significantly correlated with TBR (r=0.280, r=-0.329, r=0.188, r=0.215 respectively,all P<0.05). TBR value was significantly lower in viable myocardium<10% group, compared with viable myocardium 10%-<20% group (1.25±0.97 vs. 1.32±0.17, P<0.05) and viable myocardium≥20% group (1.25±0.97 vs. 1.34±0.16, P<0.05). Furthermore, in comparison with viable myocardium≥20% group, the hypo-metabolic regions of viable myocardium<10% group were located in the precuneus, frontal lobe, postcentral gyrus, parietal lobe, temporal lobe, and so on. Conclusions: There is a correlation between impaired left ventricular function and brain glucose metabolism in IHD patients. In IHD patients with low myocardial viability, the level of glucose metabolism in the whole brain is decreased, especially in the brain functional areas related to cognitive function.

Site‐targeted imaging enhancement of viable myocardium after ischemia‐reperfusion by a novel nano‐scale ultrasound contrast agent :a vivo study / 中华超声影像学杂志

Objective To prepare a kind of lipid nanoparticle ultrasound contrast agents with the ability to target to viable myocardium for diagnosis . Methods T he agent was a biotinylated ,fluorescent‐labelled ,lipid‐coated , liquid perfluorocarbon emulsion . Physico‐chemical properties of the agent were measured ,including size distribution ,Zeta Potential ,concentration and so on . Ischemia‐reperfusion models were created in rats ,and then exposed to biotinylated anti‐MCP‐1 monoclonal antibody ,rhodamine avidin and biotinylated ,FITC‐labelled nanoparticles ,respectively . Echocardiography was taken before and after injection . Frozen sections of their hearts were observed under fluorescence microscope . Results T he particle diameter ,zeta potential and concentration of lipid nanoparticles were ( 172 .30 ± 52 .06) nm ,( －33 .10 ± 6 .50) mV and ( 2 .28 ± 0 .46 ) × 1011/ml ,respectively . From the short‐axis view ,the myocardium under endocardium of anterior wall was enhanced obviously . While myocardium of other walls were still . T he lipid nanoparticles located in the myocardium of anterior wall and gave out bright green and red fluorescence under fluorescence microscope ,w hile neither lipid nanoparticles nor fluorescence were found in other sites of ventricular myocardium . Conclusions The viable myocardium can be targeted and acoustically enhanced by the self‐made nano‐scale ultrasound contrast agent . T his new agent has potential to improve sensitivity and specificity for noninvasive identifying viable myocardium .

Site-targeted imaging enhancement of viable myocardium after ischemia-reperfusion by a novel nano-scale ultrasound contrast agent: a vivo study / 中华超声影像学杂志

Objective@#To prepare a kind of lipid nanoparticle ultrasound contrast agents with the ability to target to viable myocardium for diagnosis.@*Methods@#The agent was a biotinylated, fluorescent-labelled, lipid-coated, liquid perfluorocarbon emulsion. Physico-chemical properties of the agent were measured, including size distribution, Zeta Potential, concentration and so on. Ischemia-reperfusion models were created in rats, and then exposed to biotinylated anti-MCP-1 monoclonal antibody, rhodamine avidin and biotinylated, FITC-labelled nanoparticles, respectively. Echocardiography was taken before and after injection. Frozen sections of their hearts were observed under fluorescence microscope.@*Results@#The particle diameter, zeta potential and concentration of lipid nanoparticles were (172.30±52.06)nm, (-33.10±6.50)mV and (2.28±0.46)×1011/ml, respectively. From the short-axis view, the myocardium under endocardium of anterior wall was enhanced obviously. While myocardium of other walls were still. The lipid nanoparticles located in the myocardium of anterior wall and gave out bright green and red fluorescence under fluorescence microscope, while neither lipid nanoparticles nor fluorescence were found in other sites of ventricular myocardium.@*Conclusions@#The viable myocardium can be targeted and acoustically enhanced by the self-made nano-scale ultrasound contrast agent. This new agent has potential to improve sensitivity and specificity for noninvasive identifying viable myocardium.

Assessment of myocardial viability and contractile function in rabbits with different ischemic periods by stress echocardiography and multilayer strain / 中华超声影像学杂志

To evaluate the changes of myocardial viability and systolic function in rabbits with different ischemic periods by layer‐specific strain of ultrasound speckled tracking imaging ( ST I) and low dose dobutamine stress echocardiography ( LDDSE ) . Methods T hirty‐six rabbits were randomly divided into 3 groups( n ＝12) : ①myocardial infarction group Ⅰ :coronary artery occlusion for 45 min ; ②myocardial infarction group Ⅱ :coronary artery occlusion for 60 min ; ③ myocardial infarction group Ⅲ :coronary artery occlusion for 90 min . Echocardiography examinations were performed at baseline ,after ligation and low dose dobutamine stress . After the experiment ,rabbits were killed and the hearts were taken to assess viable or nonviable mycardium , triphenyl tetrazolium chloride and Evans blue staining were applied . Results ①After coronary artery ligation ,left ventricular ejection fraction( LVEF) decreased in 3 groups ( all P ＜ 0 .05 ) , the ventricular global endocardial longitudinal strain ( GSLsys‐endo ) , global myocardial longitudinal strain( GSLsys‐mid) ,and global epicardial longitudinal strain( GSLsys‐epi) decreased in 3 groups ( all P ＜ 0 .05 ) ,the longitudinal strain of endocardium ( SLsys‐endo ) ,longitudinal strain of myocardium ( SLsys‐mid) ,longitudinal strain of epicardium ( SLsys‐epi) decreased in viable myocardial ( all P＜0 .05) ; ②While low dose dobutamine stressing ,the GSLsys and SLsys increased in each groups ,and the GSLsys‐endo ,GSLsys‐mid ,GSLsys‐epi and SLsys‐endo of viable segments in each group were increased ( P＜0 .05) ; ③After ligation and low dose dobutamine stress ,the GSLsys in endocardium in three groups were different( P ＜0 .05) ,and the SLsys in endocardium of viable segments in three groups were different ( P＜0 .05) . Conclusions Layer‐specific strain of STI combined with LDDSE can accurately evaluate the changes of myocardial viability and systolic function in different ischemic periods ,and the longitudinal strain of endocardium is more sensitive ;moreover ,with the increase of coronary artery occlusion time ,the infarcted myocardium increases ,myocardial viability and systolic function decrease .

Evaluation of myocardium viability by cardiac magnetic resonance in patients with chronic total occlusion lesions / 中国介入心脏病学杂志

Objective To investigate the relationship of wall motion abnormality and myocardium viability with chronic total occlusion (CTO) lesions by cardiac magnetic resonance (CMR) imaging. Methods We identified 128 patients with CTO lesion of at least one coronary artery confirmed by coronary arteriography at Beijing Anzhen Hospital between December 2014 to November 2017. All of the patients received CMR examination after admission. We analyzed the CMR images according to the AHA/American College of Cardiology 17-segment model, and recorded the left ventricular ejection fraction (LVEF), end-systolic volume (ESV) and end-distolic volume (EDV) calculated by CMR. Results In the myocardium regions corresponding to the 149 CTO lesions, only 11.5％ presented transmural myocardial infarction. A 58.6％ of the myocardial segments showed no delayed enhancement. Patients with delayed enhancement degree over 75％ had the lowest LVEF and the largest EDV and ESV. Conclusion CMR showed that patients with CTO lesions had different degrees of myocardial infarction. Patients with transmural myocardial infarction had significant cardiac function decline and ventricular remodeling. Only a fraction of patients had transmural infarction, suggesting that a majority of the CTO patients would benefit from treatment.

Intravenous Allogeneic Mesenchymal Stem Cells for Nonischemic Cardiomyopathy: Safety and Efficacy Results of a Phase II-A Randomized Trial.

RATIONALE: Potential benefits of mesenchymal stem cell (MSC) therapy in heart failure may be related to paracrine properties and systemic effects, including anti-inflammatory activities. If this hypothesis is valid, intravenous administration of MSCs should improve outcomes in heart failure, an entity in which excessive chronic inflammation may play a pivotal role. OBJECTIVE: To assess the safety and preliminary efficacy of intravenously administered ischemia-tolerant MSCs (itMSCs) in patients with nonischemic cardiomyopathy. METHODS AND RESULTS: This was a single-blind, placebo-controlled, crossover, randomized phase II-a trial of nonischemic cardiomyopathy patients with left ventricular ejection fraction ≤40% and absent hyperenhancement on cardiac magnetic resonance imaging. Patients were randomized to intravenously administered itMSCs (1.5×106 cells/kg) or placebo; at 90 days, each group received the alternative treatment. Overall, 22 patients were randomized to itMSC (n=10) and placebo (n=12) at baseline. After crossover, data were available for 22 itMSC patients. No major differences in death, hospitalization, or serious adverse events were noted between the 2 treatments. Change from baseline in left ventricular ejection fraction and ventricular volumes was not significantly different between therapies. Compared with placebo, itMSC therapy increased 6-minute walk distance (+36.47 m, 95% confidence interval 5.98-66.97; P=0.02) and improved Kansas City Cardiomyopathy clinical summary (+5.22, 95% confidence interval 0.70-9.74; P=0.02) and functional status scores (+5.65, 95% confidence interval -0.11 to 11.41; P=0.06). The data demonstrated MSC-induced immunomodulatory effects, the magnitude of which correlated with improvement in left ventricular ejection fraction. CONCLUSIONS: In this pilot study of patients with nonischemic cardiomyopathy, itMSC therapy was safe, caused immunomodulatory effects, and was associated with improvements in health status and functional capacity. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02467387.

Assessment of Myocardial Viability by Low-dose Dobutamine Stress Speckle Tracking Echocardiography and Delayed Enhancement MRI in Patients With Old Myocardial Infarction / 中国循环杂志

Objective: To compare the sensitivity and specificity between low dose dobutamine stress speckling tracking echocardiography (LDDS-STE) and delayed enhancement MRI (DE-MRI) for assessing viable myocardium (VM) in patients with old myocardial infarction (OMI). Methods: A total of 30 in-hospitalized OMI patients were enrolled, all patients received cardiac MRI and LDDS-STE prior percutaneous coronary intervention (PCI). Radial peak systolic strain (RS) and strain rate (RSr) were analyzed by LDDS-STE at both resting and loading conditions, echocardiography was performed at 1, 3 and 6 months after PCI to observe the cardiac wall motion changes and the improvement of wall motion score was taken as golden standard of VM. Results: 510 left ventricular segments were obtained for analysis in 30 patients and echocardiography indicated 201 segments with abnormal wall motion. Compared with golden standard, the area under ROC curve of RSrest for detecting VM was 0.636 with the sensitivity at 60.0% , specificity at 60.5% and the area under ROC curve of RSLDDS for detecting VM was 0.806 with the sensitivity at 79.1%, specificity at 82.7%; the area under ROC curve of RSrrest for detecting VM was 0.646 with the sensitivity at 60.0% , specificity at 60.5% and the area under ROC curve of RSrLDDS for detecting VM was 0.808 with the sensitivity at 80.0%, specificity at 83.7% which were obviously improved than RSrrest . By DE-MRI, the area under ROC curve for detecting VM was 0.901 with the sensitivity at 90.8%, specificity at 87.1% and accuracy at 89.5%. Conclusion: Both DE-MRI and LDDS-STE can recognize VM in OMI patients; while DE-MRI had the better accuracy and repeatability, cost less time which may provide important basis for predicting the efficacy of PCI and for making the treatment strategy.

Metabolism of hibernating myocardium and regulation of uncoupling protein 2 / 中国药理学通报

HM(hibernating myocardium)is an adaptive phenome-non of myocardium against sustained ischemia,which maintains its tissue vitality through balancing energy supply and demand.It widely exists in patients suffering from coronary heart disease. HMhas its own metabolic pattern,instead of regular FAO(fatty acid β-oxidation)-based metabolism,glycolysis became main pro-cedure.Reduction of FAO,TCA (tricarboxylic cacidcycle),ETC (electron transport chain)enzyme has been observed,ROS(reac-tive oxygen species)and UCP2(uncoupling protein 2)have been up-regulated.UCP2,which promotes proton leak across innermembrane of mitochondrial and leads to ATP reduction,has e-merged as an important regulator of the energy production.It is regulated by up-stream proteins such as AMPK,PPARs,PGC-1α,and other factors like FFA(free fat acid),ROS and purine nucleotide.HM has potential function of ischemic myocardium, which can improve cardiac function through reasonable interven-tion.Modulation of UCP2 can optimize energy production,and is essential to HM metabolism.

Evaluation of myocardial viability in old myocardial infarcted patients with CHF: delayed enhancement MRI vs. low-dose dobutamine stress speckle tracking echocardiography.

The aim of this study was to explore the significance of delayed enhancement magnetic resonance imaging (DE-MRI) combined with two-dimensional speckle tracking echocardiography (STE) and low dose dobutamine stress echocardiography (LDDSE) to assess viable myocardium (VM) in the patients with old myocardial infarction (OMI) associated with congestive heart failure (CHF). Thirty five hospitalized OMI patients with regional wall motion abnormalities and left ventricular ejection fraction (LVEF) < 50% were recruited based on routine echocardiography. The results showed that DE-MRI facilitated the detection of VM, with a sensitivity, specificity and accuracy of 92.41%, 89.19% and 91.32%, respectively. In a parallel test of the two main parameters in STE, the sensitivity, specificity, and accuracy were improved from baseline to LDDSE (71.72% vs. 91.72%, 70.27% vs. 85.14%, and 71.23% vs. 89.50%, P < 0.05). A parallel test involving STE with LDDSE showed high sensitivity for VM. However its specificity and accuracy were lower than DE-MRI, even when combined with LDDSE. Therefore, combining these two methods, improves the sensitivity, specificity and accuracy for assessment of VM. The combination approach is the best option for the evaluation of VM using serial test. It provides further treatment options and prognosis of patients with OMI. LVEF is improved significantly after PCI in OMI patients with VM and CHF.

Prolonged QT and myocardium recovery after primary PCI: a cMRI study.

BACKGROUND: The presence of viable stunned myocardium recovering after primary angioplasty is not easy to identify in the early phase of acute myocardial infarction (AMI) by noninvasive bed-side methods. We therefore aimed to assess whether a simple electrocardiogram parameter may be of help in identifying the presence of stunned viable myocardium recovering after reperfusion with primary angioplasty. MATERIALS AND METHODS: A total of 14 consecutive patients with ST-elevation AMI (STEMI) were enrolled in the study and underwent QT duration assessment after admission: the difference between QT corrected (QTc) in the ischaemic areas and QTc values in nonischaemic areas was therefore calculated and compared with the presence and the extension of viable stunned myocardium, assessed by comparing akinetic/dyskinetic areas at admission echocardiography with akinetic/dyskinetic areas and extension of scar at 6-month cardiac magnetic resonance imaging (cMRI). RESULTS: In subjects with viable recovering myocardium, 75% had a QTc max > 440 ms (vs. 17%, P = 0·03); higher differential QTc values and smaller scar areas were found (33 ms vs. -17 ms, 14% vs. 27%, P = 0·03, 0·06 respectively). Differential QTc values > 0 were able to identify the presence of viable myocardium with an odds ratio of 35 (P < 0·05, sensitivity 88%, specificity 83%, positive predictive power 88%, negative predictive power of 83%). Differential QTc values were related to the extension of viable recovering myocardium (P < 0·001). CONCLUSION: Viable myocardium recovering after primary angioplasty in STEMI may be predicted by the presence of increased QTc values in ischaemic areas in comparison with nonischaemic areas.

The detection of viable myocardium by low-dose dobutamine stress speckle tracking echocardiography in patients with old myocardial infarction.

PURPOSE: To explore the significance and value of speckle-tracking echocardiography (STE) associated with low-dose dobutamine stress echocardiography (LDDSE) for the detection of viable myocardium (VM) in patients with old myocardial infarction (OMI). METHODS: We performed STE with LDDSE in 33 hospitalized patients with OMI and left ventricular systolic dysfunction. QLAB software was used to analyze strain (S) and strain rate (Sr). Percutaneous coronary intervention (PCI) was subsequently performed. The movement of each wall segment was observed by routine echocardiography before and after 1, 3, and 6 months of PCI, and improvement was regarded as the gold standard for diagnosing VM. RESULTS: Compared with semi-quantitative wall-motion analysis combined with LDDSE, the sensitivity, specificity, and accuracy of c-STE (combining the three directions of S and Sr) at LDDSE were 91.6%, 79.5%, and 87.5%, respectively (p < 0.02). Among the deformation parameters, longitudinal strain (LS) and longitudinal strain rate (LSr) had the highest sensitivity, specificity, and accuracy. Upon combining LS and LSr at LDDSE to parallel tests, the sensitivity, specificity, and accuracy were 91.7%, 90%, and 90.6%, respectively. Compared with baseline, LVEF after PCI increased from 43.3% ± 2.6% to 47.3% ± 2.9% (p < 0.001). CONCLUSIONS: Global strain at LDDSE is superior to semi-quantitative wall-motion analysis with LDDSE for the assessment of VM. When the multivariable analysis and the parallel tests are combined, LS combined with LSr can be considered an independent predictor of VM. LVEF is improved after PCI in patients with VM and OMI. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:545-554, 2016.

Early prediction of myocardial viability after acute myocardial infarction by two-dimensional speckle tracking imaging.

BACKGROUND: Identifying the transmural extent of myocardial necrosis and the degree of myocardial viability in acute myocardial infarction (AMI) is important clinically. The aim of this study was to assess myocardial viability using two-dimensional speckle tracking imaging (2D-STI) in patients with AMI. METHODS: 2D-STI was performed at initial presentation, three days, and six months after primary percutaneous coronary intervention (PCI) in 30 patients with AMI, who had a left anterior descending coronary artery (LAD) culprit lesion. In addition, 20 patients who had minimal stenotic lesions (< 30% stenosis) on coronary angiography were also included in the control group. At six months dobutamine echocardiography was performed for viability assessment in seven segments of the LAD territory. According to the recovery of wall motion abnormality, segments were classified as viable or non-viable. RESULTS: A total of 131 segments were viable, and 44 were nonviable. Multivariate analysis revealed significant differences between the viable and nonviable segments in the peak systolic strain, the peak systolic strain rate at initial presentation, and peak systolic strain rate three days after primary PCI. Among these, the initial peak systolic strain rate had the highest predictive value for myocardial viability (hazard ratio: 31.22, P < 0.01). CONCLUSIONS: 2D-STI is feasible for assessing myocardial viability, and the peak systolic strain rate might be the most reliable predictor of myocardial viability in patients with AMI.

Assessment of coronary artery disease with the nitroglycerin augmented ~(99m)Tc-MIBI and ~(201)Tl dual-isotopic myocardial perfusion imaging / 中国医学影像技术

Objective To assess the clinical value of dobutamine 201Tl stress-redistribution/nitroglycerin augmented ~(99m)Tc-metho~(99m)Tc-xyisobutylisonitrile (MIBI) gated myocardial perfusion imaging (MPI) in patients with coronary artery disease (CAD). Methods A total of 132 patients with suspected CAD underwent dobutamine 201Tl stress-redistribution/nitroglycerin augmented MIBI gated MPI and coronary arteriography (CAG) within two weeks after MPI. Percutaneous coronary interventions (PCI) were performed in 23 patients with myocardial infraction. The regional wall movement was assessed with echocardiography before and within three months after PCI. Results Taking stenosis ≥50% as standard of CAD, the sensitivity, specificity and accuracy of dual-isotopic SPECT imaging in diagnosing CAD was 93.41%, 87.80% and 91.67%, respectively. The sensitivity, specificity and accuracy in diagnosing left anterior descending artery (LAD) stenosis was 93.85%, 91.04% and 92.42%, for left circumflex artery (LCX) was 86.79%, 89.87% and 88.64%, while for right coronary artery (RCA) was 81.25%, 82.14% and 81.82%, respectively. Of all 207 myocardium segments in 23 patients with myocardial infarction, radioactivity defect was found in 113 segments on the redistributed ~(201)Tl images, and radiofilling was found in 52 (52/113) segments on the nitroglycerin augmented ~(99m)Tc-MIBI images, whereas 61 segments had no radiofilling. Taking regional wall movement improvement as the criterion of viable myocardium, the sensitivity, specificity and accuracy of identifying viable myocardium with nitroglycerin augmented ~(99m)Tc-MIBI imaging was 87.23%, 83.33% and 84.96%. Conclusion Dobutamine ~(201)Tl stress-redistribution/nitroglycerin augmented ~(99m)Tc-MIBI gated MPI is able to effectively detect CAD and viable myocardium and helpful in diagnosis and treatment of CAD.

Correlations between Coronary Flow Reserve and the Presence of Viable Myocardium after Acute Anterior Myocardial Infarction

BACKGROUND: Coronary flow reserve (CFR) was defined as the ability to increase coronary blood flow maximally in response to demand. The presence of viable myocardium in an infarcted zone indicates the presence of an intact microvasculature. We hypothesized that coronary flow reserve, which assesses the microcirculation, might be associated with the presence of viable myocardium. METHODS: Thirty seven patients with acute anterior myocardial infarction (mean age 55+/-10, 25 males) were enrolled and abnormal 127 segments were analyzed. Dobutamine stress echocard-iography (5 to 20 g/kg/min) was performed before coronary angiography (6+/-3 days after acute myocardial infarction (AMI)). Coronary flow reserve in infarct-related artery was measured at distal site to lesion immediately after successful angioplasty (7+/-2 days after AMI, with residual stenosis less than 20%) by using intracoronary Doppler flow wire. And follow-up 2-dimentional transthoracic echocardiography was performed in 26 patients during 333+/-161 (range of 109-780) days after acute myocardial infarction. Improvement of wall motion at least one segment by one more grade in dobutamine stress echocardiography was defined as contractile reserve. Viable myocardium was defined as the improvement of wall motion in transthoracic echocardiography during follow-up periods. RESULTS: In 26 patients, viable myocardium was detected in 19 patients (73%) and their mean CFR was 1.74+/-0.42, which was significantly increased than 1.16+/-0.14 of CFR of patients without viable myocardium (p<0.001). The agreement of CFR score and presence of viable myocardium in AMI was excellent when CFR was above 1.3 (Area under the curve was 0.906 in receiver operating characteristic (ROC) curve). Sensitivity and specificity to detect viable myocardium in CFR more than 1.3 were 84% & 85% respectively. CONCLUSION: CFR was increased in patients with viable myocardium, and the cut-off value of CFR more than 1.3 was agreed excellently to detect viable myocardium.