Myocardial Contrast Echocardiography Research Articles

Myocardial perfusion improvement and mechanism after percutaneous intramyocardial septal radiofrequency ablation in obstructive hypertrophic cardiomyopathy: a study of myocardial contrast echocardiography.

The data on myocardial perfusion of the percutaneous intramyocardial septal radiofrequency ablation (PIMSRA) for obstructive hypertrophic cardiomyopathy (HOCM) are still lacking, although PIMSRA have been proved to be of great safety and efficacy. The aim of this study was to quantitatively analyze the changes in myocardial perfusion after PIMSRA using myocardial contrast echocardiography (MCE). 27 HOCM patients treated with PIMSRA were retrospectively analyzed, and their echocardiographic parameters and perfusion parameters of MCE were collected before and 12 months after PIMSRA. A reperfusion curve was used to quantify microvascular blood volume (A), microvascular flux rate (β), and microvascular blood flow (MBF) of each segment. Then the value difference (Δ) of parameters between post- and pre-operation were calculated. Finally, the correlation between the changes in MBF and in each echocardiographic parameter was analyzed. (1) Compared with baseline, the global A, β and MBF were significantly increased in HOCM patients after PIMSRA (all P < 0.001). The β, MBF were increased in the interventricular septum (P < 0.001, respectively), and the A, β, MBF were increased in the left ventricular wall (all P < 0.001). (2) Correlation analysis showed that the ΔMBF of interventricular septum was mainly negatively correlated with the maximum interventricular septum thickness (ΔIVSTmax, r=-0.670, P < 0.001), mean interventricular septum thickness (ΔIVSTmean, r=-0.690, P < 0.001), and left ventricular mass index (ΔLVMI, r=-0.774, P < 0.001), while the ΔMBF of left ventricular wall was positively correlated with left ventricular end-diastolic volume index (ΔLVEDVI, r = 0.621, P = 0.001) and stroke volume index (ΔSVI, r = 0.810, P < 0.001). Myocardial perfusion was improved at both interventricular septum and ventricular wall in HOCM patients after PIMSRA. MCE can provide a new dimension for the efficacy evaluation to PIMSRA procedure.

Coronary Microvascular Dysfunction in Acute Cholestasis-Induced Liver Injury.

Previous studies have shown cardiac abnormalities in acute liver injury, suggesting a potential role in the associated high mortality. We designed an experimental study exploring the short-term effects of acute cholestasis-induced liver injury on cardiac function and structure in a rodent bile duct ligation (BDL) model to elucidate the potential interplay. Thirty-seven male Sprague-Dawley rats were subjected to BDL surgery (n = 28) or served as sham-operated (n = 9) controls. Transthoracic echocardiography, Doppler evaluation of the left anterior descending coronary artery, and myocardial contrast echocardiography were performed at rest and during adenosine and dobutamine stress 5 days after BDL. Immunohistochemical staining of myocardial tissue samples for hypoxia and inflammation as well as serum analysis were performed. BDL animals exhibited acute liver injury with elevated transaminases, bilirubin, and total circulating bile acids (TBA) 5 days after BDL (TBA control: 0.81 ± 2.54 µmol/L vs. BDL: 127.52 ± 57.03 µmol/L; p < 0.001). Concurrently, cardiac function was significantly impaired, characterized by reduced cardiac output (CO) and global longitudinal strain (GLS) in the echocardiography at rest and under pharmacological stress (CO rest control: 120.6 ± 24.3 mL/min vs. BDL 102.5 ± 16.6 mL/min, p = 0.041; GLS rest control: -24.05 ± 3.8% vs. BDL: -18.5 ± 5.1%, p = 0.01). Myocardial perfusion analysis revealed a reduced myocardial blood flow at rest and a decreased coronary flow velocity reserve (CFVR) under dobutamine stress in the BDL animals (CFVR control: 2.1 ± 0.6 vs. BDL: 1.7 ± 0.5 p = 0.047). Immunofluorescence staining indicated myocardial hypoxia and increased neutrophil infiltration. In summary, acute cholestasis-induced liver injury can lead to impaired cardiac function mediated by coronary microvascular dysfunction, suggesting that major adverse cardiac events may contribute to the mortality of acute liver failure. This may be due to endothelial dysfunction and direct bile acid signaling.

Cardiac Allograft Vasculopathy: Challenges and Advances in Invasive and Non-Invasive Diagnostic Modalities.

Cardiac allograft vasculopathy (CAV) is a distinct form of coronary artery disease that represents a major cause of death beyond the first year after heart transplantation. The pathophysiology of CAV is still not completely elucidated; it involves progressive circumferential wall thickening of both the epicardial and intramyocardial coronary arteries. Coronary angiography is still considered the gold-standard test for the diagnosis of CAV, and intravascular ultrasound (IVUS) can detect early intimal thickening with improved sensitivity. However, these tests are invasive and are unable to visualize and evaluate coronary microcirculation. Increasing evidence for non-invasive surveillance techniques assessing both epicardial and microvascular components of CAV may help improve early detection. These include computed tomography coronary angiography (CTCA), single-photon emission computed tomography (SPECT), positron emission tomography (PET), and vasodilator stress myocardial contrast echocardiography perfusion imaging. This review summarizes the current state of diagnostic modalities and their utility and prognostic value for CAV and also evaluates emerging tools that may improve the early detection of this complex disease.

Ultrasound study of right ventricular myocardial perfusion and functional changes in hypertrophic cardiomyopathy.

To evaluate the changes of right ventricular (RV) myocardial perfusion and function in patients with hypertrophic cardiomyopathy (HCM) by myocardial contrast echocardiography (MCE) and speckle tracking (2D-STE), and to explore the relationship between RV myocardial perfusion and strain. Conventional ultrasound, MCE and 2D-STE were performed on 29 HCM patients and 21 healthy subjects to analyze RV myocardial perfusion, RV global strain, RV free wall strain, and strain of each segment. The correlation between RV myocardial perfusion and strain was further analyzed in HCM patients. MCE results showed that the regional myocardial perfusion of the RV in HCM patients was decreased. Compared with the normal control group, the mean slope (β) in the middle and apical segments of the RV free wall, and the peak intensity (A), β, myocardial blood flow (MBF) of the ventricular septum decreased in HCM patients (P < 0.05). RV function was impaired in HCM patients. The RV global strain (RV GLS), and the strain of RV free wall and each segment were lower than those in the normal control group (P < 0.05). Correlation analysis showed that there was a certain correlation between RV myocardial perfusion and strain, such as the β of the whole RV in HCM group had a positive correlation with the strain of the middle segment of the interventricular septum (r = 0.550, P = 0.002). The regional myocardial perfusion and strain of the RV in HCM patients are reduced, and there is a positive correlation between them, suggesting that the reduction of myocardial strain may be related to the impairment of myocardial microcirculation.

Establishment of nonobstructive coronary microcirculatory disorders in rabbits using three established methods and a comparative study

To compare the merits and drawbacks of three approaches for establishing a rabbit model of nonobstructive coronary microcirculatory disease, namely, open thoracic subtotal ligation of coronary arteries, ultrasound-guided cardiac microsphere injection, and sodium laurate injection. New Zealand rabbits were allocated to four groups: a normal group (Blank group), an Open-chest group (Open-chest), a microsphere group (Echo-M), and a sodium laurate group (Echo-SL), each comprising 10 rabbits. The rabbits were sacrificed 24 h after the procedures, and their echocardiography, stress myocardial contrast echocardiography, pathology, and surgical times were compared. The results demonstrated varying degrees of reduced cardiac function in all three experimental groups, the Open-chest group exhibiting the most significant decline. The myocardial filling in the affected areas was visually analyzed by myocardial contrast echocardiography, revealing sparse filling at rest but more after stress. Quantitative analysis of perfusion parameters (β, A, MBF) in the affected myocardium showed reduced values, the Open-chest group having the most severe reductions. No differences were observed in stress myocardial acoustic imaging parameters between the Echo-M and Echo-SL groups. Among the pathological presentations, the Open-chest model predominantly exhibited localized ischemia, while the Echo-M model was characterized by mechanical physical embolism, and the Echo-SL model displayed in situ thrombosis as the primary pathological feature. Inflammatory responses and collagen deposition were observed in all groups, with the severity ranking of Open-chest > Echo-SL > Echo-M. The ultrasound-guided intracardiac injection method used in this experiment outperformed open-chest surgery in terms of procedural efficiency, invasiveness, and maneuverability. This study not only optimizes established cardiac injection techniques but also offers valuable evidence to support clinical investigations through a comparison of various modeling methods.

Myocardial Contrast Echocardiography as a mode of evaluation of asymptomatic ECG abnormality

Myocardial Contrast Echocardiography as a mode of evaluation of asymptomatic ECG abnormality

Association between Troponin Elevation and Decreased Myocardial Blood Flow Reserve in Patients without Obstructive Coronary Artery Disease

Introduction: To study the prognostic factors of patients with chest pain and without obstructive coronary artery disease is of great significance for the management of such patients. We assessed whether a high-sensitivity troponin I (hs-TnI) is associated with prognosis in patients with chest pain and without obstructive coronary artery disease. Methods: From 2011 to 2017, 489 consecutively hospitalized patients with chest pain and without significant coronary artery stenosis (<50%) were tested for hs-TnI and underwent stress myocardial contrast echocardiography (MCE). Myocardial blood flow reserve (MBFR) was measured by stress MCE. Patients were followed (median, 41 months) for composite endpoints, including cardiovascular death and non-fatal myocardial infarction. Cox proportional hazards models were performed to determine associations between hs-TnI and the composite endpoints. Results: Among 489 patients with chest pain and without significant coronary artery stenosis, 257 patients (52.6%) had elevated hs-TnI. Compared to patients with normal hs-TnI, patients with elevated hs-TnI were older (p = 0.013) and had a higher prevalence of atrial fibrillation (p = 0.003), higher left ventricular mass index (p = 0.002) and E/e’ septal (p < 0.001), and a lower MBFR (p < 0.001). After adjustment, there was still a significant association between hs-TnI and MBFR (odds ratio = 1.145; 95% confidence interval [CI], 1.079–1.214; p < 0.001). Compared with patients with normal hs-TnI, patients with elevated hs-TnI had a greater cumulative event rate (log-rank p = 0.002). Males (hazard ratio [HR], 4.770; 95% CI, 1.175–19.363; p = 0.029) and reduced MBFR (HR, 2.496; 95% CI, 1.446–4.311; p = 0.001) were risk factors associated with composite endpoints in patients with elevated hs-TnI. Conclusions: In patients with chest pain and without obstructive coronary artery disease, elevated hs-TnI is associated with decreased myocardial perfusion by contrast echocardiography as well as a higher incidence of cardiovascular events.

Abstract 12378: Association of Hypertensive Disorders of Pregnancy With Coronary Microvascular Dysfunction 8-10 Years After Delivery

Introduction: Hypertensive disorders of pregnancy ( HDP ) are associated with subsequent adverse cardiac remodeling and cardiovascular disease ( CVD ). The pathophysiologic mechanisms linking HDP to CVD, including the role of myocardial microvascular disease, are understudied. Hypothesis: Individuals with HDP history will have abnormal microvascular coronary flow reserve ( CFR ) 8-10 years after delivery and abnormal CFR will correlate with left ventricular ( LV ) remodeling. Methods: Individuals with pregnancies delivered 2008-2010 underwent burst-replenishment myocardial contrast echocardiography (2017-2020) to quantify myocardial perfusion at rest and during dobutamine stress. Video intensity vs. time data were used to derive β, the rate of rise of video intensity, a correlate for myocardial blood flow. CFR was calculated as the ratio of β at peak stress to β at rest, averaged across LV myocardial regions of interest. Results: We studied 91 individuals (age 38±6, 9.1±0.9 years post-delivery), 19 with a history of HDP). Individuals with abnormal CFR (β ratio &lt;2.0, n=13) had higher pre-pregnancy BMI, baseline heart rate, hemoglobin A1c, and a history of HDP (46.2% vs 16.7%; p =0.026). Association of CFR and HDP was attenuated after adjusting for pre-pregnancy BMI and hemoglobin A1c ( p =0.114). In exploratory subgroup analyses, individuals with both LV remodeling (relative wall thickness&gt;0.42) and HDP had the highest proportion of microvascular dysfunction (41.7% vs. +HDP-LV remodeling 14.3%, -HDP+LV remodeling 7.7%; p =0.0498). Conclusions: Individuals with HDP history may be more likely to have coronary microvascular dysfunction one decade after delivery. Larger studies are needed to determine if microvascular dysfunction may be a mechanism for development of CVD among individuals with HDP.

Contrast Echocardiography for Assessing Myocardial Perfusion.

Improvements in ultrasound methods for detecting microbubble ultrasound enhancing agents have led to an increase in the use of perfusion imaging with myocardial contrast echocardiography (MCE). This technique is now beginning to play an important role in specific clinical scenarios, which is the focus of this review. MCE was originally conceived as a technique for detecting resting perfusion abnormalities related to ischemia at rest or during stress from coronary artery disease. More recently, MCE has increasingly been used in circumstances where the technique's ability to provide rapid, quantitative, or bedside assessment of perfusion is advantageous. Quantitative MCE is also increasingly being used as a research technique for evaluating pathobiology and therapy that involve changes in the myocardial microcirculation. While MCE was developed and validated decades ago, it is only now beginning to be used by an increasing number of clinicians due to improvements in imaging technology and recognition of specific situations where the technique is impactful.

Automatic Myocardial Contrast Echocardiography Image Quality Assessment Using Deep Learning: Impact on Myocardial Perfusion Evaluation.

The image quality of myocardial contrast echocardiography (MCE) is critical for precise myocardial perfusion evaluation but challenging for echocardiographers. Differences in quality may lead to diagnostic heterogeneity. This study was aimed at achieving automatic MCE image quality assessment using a deep neural network (DNN) and investigating its impact on myocardial perfusion evaluation. The Resnet-18 model was used for training and testing on internal and external data sets. Quality assessment involved three aspects: left ventricular opacification (LVO), shadowing, and flash adequacy; the quality score was calculated based on image quality. This study explored the impact of the DNN-based quality score on perfusion evaluation (normal, delay or obstruction) by echocardiographers (two seniors, one junior and one novice). Additionally, the effect of the score difference between re-scans on perfusion evaluation was investigated. The time cost for DNN prediction was 0.045 s/frame. In internal validation and external testing, the DNN achieved F1 and macro F1 scores >90% for quality assessment and had high intraclass correlation coefficients (0.954 and 0.892, respectively) in sequence quality scores. The proportion of segments deemed uninterpretable increased as the DNN-based quality score decreased. The agreement of perfusion assessment between one senior and others decreased as the quality score decreased. And the greater the score difference between the re-scans, the lower was the agreement on perfusion assessment by the same echocardiographer. This study determined the effectiveness of DNN for real-time automatic MCE quality assessment. It has the potential to reduce the variability in perfusion evaluation among echocardiographers.

ATP Stress Myocardial Contrast Echocardiography Assessment of Coronary Microvascular Disease with Spasmodic Characteristics: A Case Report

Here, a patient with chest pain and &lt;50% stenosis on coronary angiography, where ATP stress myocardial contrast echocardiography (MCE) revealed that coronary flow reserve was reduced to 1.71 was presented. Perfusion delay occurred in the left ventricular wall of the apex of the heart before ATP stress, and the perfusion delay area was significantly reduced at peak stress. Similar to the characteristics of “reverse redistribution” of radionuclide myocardium perfusion in coronary vasospasm, the delayed perfusion area in the recovery period was larger than that detected before stress. Together with increased spectral resistance of the distal segment of left anterior descending coronary artery and chest pain, these findings indicated coronary microvascular disease with spasmodic characteristics in this patient. The perfusion characteristics on ATP stress determined by MCE and changes in coronary spectrum have value for the diagnosis and treatment of coronary microvascular disease with spasmodic characteristics.

Retracted: Evaluation of Cardiac Space-Occupying Lesions by Myocardial Contrast Echocardiography and Transesophageal Echocardiography.

[This retracts the article DOI: 10.1155/2022/2066033.].

Value of Myocardial Contrast Echocardiography in Detecting Coronary Microcirculatory Dysfunction in Ischemia With Non-obstructive Coronary Artery Disease

The aim of this study was to evaluate the value of myocardial contrast echocardiography (MCE) in detecting coronary microcirculation function dysfunction in ischemia with non-obstructive coronary artery (INOCA) disease. Twenty-one patients with a clinical diagnosis of INOCA were admitted to the First Affiliated Hospital of Xinjiang Medical University because of chest pain. All participants underwent MCE and [18F]fluorodeoxyglucose (FDG) positron emission tomography/computed tomography myocardial metabolic imaging. With the results of FDG PET taken as the gold standard, all myocardial segments were divided into a normal control group and a coronary artery microcirculation dysfunction (CMCD) group. We used MCE to measure myocardial perfusion parameters, including the ascending slope (β), time to peak (TTP), A and A×β. The receiver operating characteristic (ROC) curves of β, TTP, A and A×β were calculated to evaluate the diagnostic value of MCE for CMCD. A total of 122 and 218 segments were investigated in the CMCD and control groups, respectively. On the basis of the statistical analysis of the MCE parameters of the two groups, the myocardial perfusion parameters β, A and A×β of all segments in the CMCD group decreased, and the TTP in the basal segment of the CMCD group was longer than that of the normal control group (all p values <0.05). On the basis of analysis of the ROC curve, β had the highest diagnostic efficiency in the middle segment. This study found that MCE is valuable in the diagnosis of non-obstructive coronary artery complicated by CMCD.

Association Between Segmental Noninvasive Myocardial Work and Microvascular Perfusion in ST-Segment Elevation Myocardial Infarction: Implications for Left Ventricular Functional Recovery and Clinical Outcomes

Predicting left ventricular recovery (LVR) after acute ST-segment elevation myocardial infarction (STEMI) is of prognostic importance. This study aims to explore the prognostic implications of segmental noninvasive myocardial work (MW) and microvascular perfusion (MVP) after STEMI. In this retrospective study, 112 patients with STEMI who underwent primary percutaneous coronary intervention and transthoracic echocardiography after percutaneous coronary intervention were enrolled. Microvascular perfusion was analyzed by myocardial contrast echocardiography, and segmental MW was analyzed by noninvasive pressure-strain loops. A total of 671 segments with abnormal function at baseline were analyzed. The degrees of MVP were observed following intermittent high-mechanical index impulses: replenishment within 4seconds (normal MVP), replenishment >4seconds and within 10seconds (delayed MVP), and persistent defect (microvascular obstruction). The correlation between MW and MVP was analyzed. The correlation of the MW and MVP with LVR (normalization of wall thickening, >25%) was assessed. The prognostic value of segmental MW and MVP for cardiac events (cardiac death, admission for congestive heart failure, or recurrent myocardial infarction) was evaluated. Normal MVP was seen in 70 segments, delayed MVP in 236, and microvascular obstruction in 365. The segmental MW indices were independently correlated with MVP; 244 (36.4%) segments had segmental LVR at 3-month follow-up. Segmental MW efficiency and MVP were independently associated with segmental LVR (P<.05). The χ2 of combination of segmental MW efficiency and MVP was higher than either index alone for identifying segmental LVR (P<.001). At a median follow-up of 42.0months, cardiac events occurred in 13 patients; all regional MW parameters, high sensitivity troponin I, regional longitudinal strain, and so on were associated with cardiac events. Segmental MW indices are associated with MVP within the infarct zone following reperfused STEMI. Both are independently associated with segmental LVR, and regional MW is associated with cardiac events, providing prognostic value in STEMI patients.

0008 The endogenous circadian system provides for enhanced coronary microvascular function in the morning

Abstract Introduction Major adverse cardiovascular events occur most commonly in the morning compared to other times of the day or night. Evaluation of coronary microvascular reserve perfusion can be used to reflect the anatomic and functional status of the coronary vascular system, both of which contribute to major adverse cardiovascular events. Prior work suggests that coronary microvascular function is attenuated in the morning, but whether the circadian system contributes to this attenuation is unknown. Methods To determine if the circadian system drives the morning attenuation in coronary microvascular function, we studied 13 healthy participants (8 females, 5 males; 42+/-13 years [mean+/-SD]) in a 5-day forced desynchrony protocol in dim light, where all behaviors and measurements were distributed across the 24-hour cycle. Coronary microvascular function was evaluated by vasodilator myocardial contrast echocardiography, sequentially 16 hours apart, corresponding to each participant’s morning, evening and night. We analyzed time-intensity data to calculate microvascular flux rate (beta) at rest and during hyperemia for each measurement. Circadian phases were calculated based on individual dim-light melatonin onsets. We grouped data into three ~8-hour circadian bins corresponding to each participant’s morning, evening and night. Mixed model analyses were used to determine if there were significant differences between data collected in the circadian morning compared to the other times while controlling for the measurement schedule and between-subject variability. Results There were no significant time-dependent differences in echocardiographic indices of ventricular function, including stroke volume, cardiac output, or myocardial work. Contrary to our hypothesis, hyperemic perfusion was lowest in the evening rather than the morning (2.49 /s vs. 2.82 /s, p=0.042) but not different between morning and night (also 2.82 /s, p=0.96). Conclusion In healthy people, there is no circadian-system-driven morning attenuation in coronary microvascular function: indeed, the circadian system facilitates coronary vascular flow in the morning, possibly to accommodate the anticipated behaviorally driven increases in myocardial demand after awakening. Support (if any) NIH KL2TR002370, R01HL163232, R35HL155681, R01HL140577, R01HL130046, R01HL078610, R01HL156948, K01HL146992, K01HL151745, ULTR00128, Sleep Research Society Foundation, Oregon Institute of Occupational Health Sciences.

A novel risk stratification model for STEMI after primary PCI: global longitudinal strain and deep neural network assisted myocardial contrast echocardiography quantitative analysis.

In ST-segment elevation myocardial infarction (STEMI) with the restoration of TIMI 3 flow by percutaneous coronary intervention (PCI), visually defined microvascular obstruction (MVO) was shown to be the predictor of poor prognosis, but not an ideal risk stratification method. We intend to introduce deep neural network (DNN) assisted myocardial contrast echocardiography (MCE) quantitative analysis and propose a better risk stratification model. 194 STEMI patients with successful primary PCI with at least 6 months follow-up were included. MCE was performed within 48 h after PCI. The major adverse cardiovascular events (MACE) were defined as cardiac death, congestive heart failure, reinfarction, stroke, and recurrent angina. The perfusion parameters were derived from a DNN-based myocardial segmentation framework. Three patterns of visual microvascular perfusion (MVP) qualitative analysis: normal, delay, and MVO. Clinical markers and imaging features, including global longitudinal strain (GLS) were analyzed. A calculator for risk was constructed and validated with bootstrap resampling. The time-cost for processing 7,403 MCE frames is 773 s. The correlation coefficients of microvascular blood flow (MBF) were 0.99 to 0.97 for intra-observer and inter-observer variability. 38 patients met MACE in 6-month follow-up. We proposed A risk prediction model based on MBF [HR: 0.93 (0.91-0.95)] in culprit lesion areas and GLS [HR: 0.80 (0.73-0.88)]. At the best risk threshold of 40%, the AUC was 0.95 (sensitivity: 0.84, specificity: 0.94), better than visual MVP method (AUC: 0.70, Sensitivity: 0.89, Specificity: 0.40, IDI: -0.49). The Kaplan-Meier curves showed that the proposed risk prediction model allowed for better risk stratification. The MBF + GLS model allowed more accurate risk stratification of STEMI after PCI than visual qualitative analysis. The DNN-assisted MCE quantitative analysis is an objective, efficient and reproducible method to evaluate microvascular perfusion.

Elevated LDL Cholesterol Increases Microvascular Endothelial VWF and Thromboinflammation After Myocardial Infarction.

In reperfused myocardial infarction, VWF (von Willebrand factor)-mediated platelet adhesion contributes to impaired microvascular reflow and possibly also to postmyocardial infarction inflammation. We hypothesized that postischemic thromboinflammatory processes are worsened by elevated LDL (low-density lipoprotein) cholesterol. Myocardial ischemia-reperfusion or sham procedure was performed in wild-type mice and hyperlipidemic mice deficient for the LDL receptor and Apobec-1 (apolipoprotein-B mRNA editing enzyme catalytic polypeptide-1; DKO [double knockout]). DKO subgroups were treated with N-acetylcysteine, which inhibits pro-adhesive VWF multimers or with recombinant ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin motifs-13), which enzymatically cleaves endothelial surface-associated VWF. Myocardial contrast echocardiography perfusion imaging and molecular imaging for VWF, platelet glycoprotein Ibα, and leukocyte CD18 (cluster of differentiation) were performed 30 minutes post-reperfusion. Histology, infarct sizing, and echocardiography were performed at 1.5 or 72 hours; late echocardiography was performed at day 21. After ischemia-reperfusion, DKO compared with wild-type mice had ≈2-fold higher (P<0.05) risk area signal for microvascular platelet adhesion, VWF, and CD18; greater impairment in microvascular reflow, and 2-fold larger infarct size. Treatment of DKO mice with N-acetylcysteine and ADAMTS13 reduced molecular imaging signal for microvascular platelet adhesion, VWF, and CD18; improved early microvascular reflow; and reduced eventual infarct size. ADAMTS13 suppressed the postmyocardial infarction neutrophil and monocyte infiltration, enhanced the time-dependent recovery of left ventricular systolic function, and prevented late left ventricular remodeling. In reperfused myocardial infarction, elevated LDL cholesterol promotes thromboinflammation through excess microvascular endothelial VWF and platelet adhesion, resulting in less microvascular reflow and larger infarct size. In the presence of elevated LDL cholesterol, therapies that suppress endothelial-associated VWF can promote recovery of left ventricular function and protect against remodeling.

Misplacement in myocardial contrast echo during alcohol septal ablation in hypertrophic obstructive cardiomyopathy indicates intraseptal collateralization.

A 42-year-old patient with HOCM was submitted for percutaneous transluminal septal myocardial ablation (PTSMA). Coronary angiography (Panel A) identified the first septal branch (SB) (yellow arrow) as estimated target vessel and a second SB (white arrow). Compared with intraprocedural baseline transthoracic echocardiography (TTE) (Panel B), myocardial contrast echocardiography (MCE) with injection of 1.5 mL cold gelafundin 4% through an inflated over the wire balloon catheter (OTW-BC) in the first SB (Panel C) identified a correct septal depot (orange arrow), but also opacification at the left ventricle apex (dotted orange arrow). Contrast dye injection through the OTW-BC (dotted yellow arrow) showed collateralization from the first (yellow arrow) into the second SB (yellow arrow) and drainage into the left anterior descending (LAD) (red arrow) as reason for the misplacement (Panel D). We placed a second OTW-BC in the collateralized second SB (dotted white arrow; Panel E). Contrast injection through both inflated OTW-BC showed only distal first (yellow arrow) and second SB (white arrow) without further collaterals and without drainage into the—in the meantime wired—LAD (red arrow). MCE (Panel E) showed only opacification of the targeted septal area (orange arrow) as TTE (Panel F) does after injection 1.5 cc of alcohol through each balloon. After deflation and retraction of the BCs, 10 min after alcohol injection, haemodynamic measurements ensured elimination of resting and provocable gradients. Final coronary angiography (Panel G) showed occluded SBs (arrows) and unchanged LAD.

[Microvascular perfusion and cardiac function after revascularization assessed by myocardial contrast echocardiography in patients with acute ST-segment elevation myocardial infarction].

Objectives: To evaluate microvascular perfusion and left ventricular function in patients with acute ST-segment elevation myocardial infarction after revascularization using myocardial contrast echocardiography (MCE), and to explore clinical influencing factors of abnormal microvascular perfusion in these patients. Methods: This is a cross-sectional study. The analysis was performed among patients admitted to Peking University People's Hospital for acute ST-segment elevation myocardial infarction (STEMI) from June 2018 to July 2021. All patients underwent percutaneous coronary intervention (PCI) and completed MCE within 48 hours after PCI. Patients were divided into normal myocardial perfusion group and abnormal perfusion group according to the myocardial perfusion score. The echocardiographic indexes within 48 hours after PCI, including peak mitral valve flow velocity (E), mean value of early diastolic velocity of left ventricular septum and lateral mitral annulus (Em), left ventricular global longitudinal strain (GLS) and so on, were analyzed and compared between the two groups. Multivariate logistic regression analysis was used to evaluate the influencing factors of myocardial perfusion abnormalities. Results: A total of 123 STEMI patients, aged 59±13 years with 93 (75.6%) males, were enrolled. There were 50 cases in the normal myocardial perfusion group, and 73 cases in the abnormal myocardial perfusion group. The incidence of abnormal myocardial perfusion was 59.3% (73/123). The left ventricular volume index ((62.3±18.4)ml/m2 vs. (55.1±15.2)ml/m2, P=0.018), wall motion score index (WMSI) (1.59 (1.44, 2.00) vs. 1.24(1.00, 1.47), P<0.001) and mitral E/Em (17.8(12.0, 24.3) vs. 12.2(9.2, 15.7), P<0.001) were significantly higher whereas left ventricular global longitudinal strain (GLS) ((-10.8±3.4)% vs. (-13.8±3.5)%, P<0.001) was significantly lower in the abnormal myocardial perfusion group than those in the normal myocardial perfusion group. Multivariate logistic regression analysis showed that left anterior descending (LAD) as culprit vessel (OR=3.733, 95%CI 1.282-10.873, P=0.016), intraoperative no/low-reflow (OR=6.125, 95%CI 1.299-28.872, P=0.022), and peak troponin I (TnI) (OR=1.018, 95%CI 1.008-1.029, P=0.001) were independent risk factors of abnormal myocardial perfusion. As for ultrasonic indexes, deceleration time of mitral E wave (OR=0.979, 95%CI 0.965-0.993, P=0.003), mitral E/Em (OR=1.100, 95%CI 1.014-1.194, P=0.022) and WMSI (OR=7.470, 95%CI 2.630-21.222, P<0.001) were independently related to abnormal myocardial perfusion. Conclusions: The incidence of abnormal myocardial perfusion after PCI is high in patients with acute STEMI. Abnormal myocardial perfusion is related to worse left ventricular systolic and diastolic function. LAD as culprit vessel, intraoperative no/low-reflow and peak TnI are independent risk factors of abnormal myocardial perfusion.

Dynamic evolution of left ventricular strain and microvascular perfusion assessed by speckle tracking echocardiography and myocardial contrast echocardiography in diabetic rats: Effect of dapagliflozin.

This experimental study aimed to determine the dynamic changes in myocardial strain and microvascular perfusion in diabetic rats by comprehensive echocardiography while evaluating the effect of dapagliflozin (DAPA). Male Sprague-Dawley rats (n = 128) were randomly divided into four groups based on the presence or absence of a high-fat diet and streptozotocin-induced diabetes with or without DAPA treatment (n = 32/group). Serial conventional ultrasound, two-dimensional speckle tracking echocardiography (2D-STE) and myocardial contrast echocardiography (MCE) were performed at 2, 4, 6, and 8 weeks, and left ventricular global longitudinal strain (GLS), myocardial blood flow velocity (MBFV), myocardial blood flow (MBF), and myocardial blood volume (MBV) were determined. All animals were sacrificed immediately after the last echo measurement for histopathological assessment. Despite similar conventional Doppler-echo indexes among the groups at 2, 4, 6, and 8 weeks (p > 0.05), left ventricular GLS, MBFV, MBF, and MBV were decreased at 8 weeks in diabetic rats (p < 0.05) as detected by both 2D-STE and MCE. These indexes were significantly improved at 6 and 8 weeks after treatment with DAPA for diabetic rats (p < 0.05), reaching similar values observed in non-diabetic controls. DAPA treatment was associated with increased myocardial vacuolization and microvessel density and reduced interstitial fibrosis in diabetic rats. Combined 2D-STE and MCE is sensitive for detecting left ventricular deformity and impaired microvascular perfusion in prediabetes and the early stage of diabetes mellitus. DAPA exerts a beneficial effect on protecting myocardial perfusion in diabetic rats.