Assessment and Treatment for Coronary Microvascular Dysfunction by Contrast Enhanced Ultrasound

Association Between First-Phase Left Ventricular Ejection Fraction and Severity of Coronary Artery Stenosis and Changes With Interventional Treatment

BACKGROUND

Myocardial ischemia can impair the speed and intensity of myocardial contractility, frequently undetectable by conventional echocardiography in early stages. The aim of this study was to assess whether first-phase left ventricular ejection fraction (LVEF-1), a sensitive myocardial contractility marker, correlates with ischemia severity and improves following interventional treatment.

METHODS AND RESULTS

Two hundred seven patients were categorized into mild, moderate, and severe groups based on angiographic coronary maximal stenosis. LVEF-1, Gensini scores, and clinical data were compared among these groups. Logistic regression was used to assess the association between LVEF-1 and coronary artery stenosis, and linear regression identified factors linked to postintervention LVEF-1 improvement. The median LVEF-1 in the 3 groups was 29.6% (28.2-31.7), 27.8% (27.0-28.6), and 25.2% (23.6-26.5) (P<0.001). LVEF-1 showed inverse correlation with Gensini score (r=-0.694, P<0.001) and BNP (B-type natriuretic peptide; r=-0.244, P<0.001). LVEF-1 was independently associated with coronary artery stenosis ≥50% or ≥70%. A cutoff value of 26.9% for LVEF-1 had a sensitivity of 89.5% and specificity of 83.9% for predicting coronary artery stenosis ≥70%. Following intervention, LVEF-1 increased from 24.70% (23.30-26.32) to 28.10% (26.80-29.92) in 82 patients. Stent diameter was identified as an independent factor associated with improvement in LVEF-1 post intervention.

CONCLUSIONS

LVEF-1 is negatively correlated with the severity of coronary artery stenosis, and it improves significantly after coronary artery intervention therapy, suggesting that LVEF-1 can serve as a novel indicator for assessing coronary artery stenosis severity and monitoring the efficacy of interventional treatment.

Ultrasound-mediated cardiovascular thrombolysis: from Sonothrombolysis to Sonoperfusion

The incidence of coronary artery disease has been increasing in recent years, with acute myocardial infarction as its most severe onset. The major aim for clinical treatment is to restore myocardial blood supply with the recanalization of coronary circulation as early as possible, while the still existed issue of microcirculation thromboembolism has become a serious obstacle. Thus, thrombus elimination in coronary microcirculation is crucial and essential to improve the treatment outcome of acute myocardial infarction. In recent years, from sonothrombolysis to sonoperfusion, ultrasound-mediated cardiovascular thrombolysis can effectively solve the problem of vascular thromboembolism, including microcirculation thromboembolism, and the treatment method is expected to obtain satisfied thrombolytic treatment effect with microthrombus elimination in coronary microvessels and function recovery of terminal microcirculation, which has potential clinical value for the establishment of novel treatment for coronary thromboembolism. Therefore, this paper reviews ultrasound-mediated cardiovascular thrombolysis including sonothrombolysis and sonoperfusion for the application exploration in the treatment of coronary artery thromboembolism, the mechanism of action, and its research progress.

Advances in the diagnosis and management of post-percutaneous coronary intervention coronary microvascular dysfunction: Insights into pathophysiology and metabolic risk interactions

Percutaneous coronary intervention (PCI), as an essential treatment for coronary artery disease, has significantly improved the prognosis of patients with large coronary artery lesions. However, some patients continue to experience myocardial ischemic symptoms post-procedure, largely due to coronary microvascular dysfunction (CMD). The pathophysiological mechanisms of CMD are complex and involve endothelial dysfunction, microvascular remodeling, reperfusion injury, and metabolic abnormalities. Moreover, components of metabolic syndrome, including obesity, hyperglycemia, hypertension, and dyslipidemia, exacerbate the occurrence and progression of CMD through multiple pathways. This review systematically summarizes the latest research advancements in CMD after PCI, including its pathogenesis, diagnostic techniques, management strategies, and future research directions. For diagnosis, invasive techniques such as coronary flow reserve and the index of microcirculatory resistance, as well as non-invasive imaging modalities (positron emission tomography and cardiac magnetic resonance), provide tools for early CMD detection. In terms of management, a multi-level intervention strategy is emphasized, incorporating lifestyle modifications (diet, exercise, and weight control), pharmacotherapy (vasodilators, hypoglycemic agents, statins, and metabolic modulators), traditional Chinese medicine, and specialized treatments (enhanced external counterpulsation, metabolic surgery, and lipoprotein apheresis). However, challenges remain in CMD treatment, including limitations in diagnostic tools and the lack of personalized treatment strategies. Future research should focus on the complex interactions between CMD and metabolic risks, aiming to optimize diagnostic and therapeutic strategies to improve the long-term prognosis of patients post-PCI.

Multimodality Imaging in the Diagnosis of Coronary Microvascular Disease: An Update

Coronary microvascular dysfunction (CMD) is characterized by structural and functional abnormalities in the coronary microvasculature which can lead to ischaemia and angina and is increasingly recognized as a major contributor to adverse cardiovascular outcomes. Despite its clinical importance, the diagnosis of CMD remains limited compared with traditional atherosclerotic coronary artery disease. Furthermore, the historical lack of non-invasive methods for detecting and quantifying CMD has hindered progress in understanding its pathophysiology and clinical implications. This review explores advancements in non-invasive cardiac imaging that have enabled the detection and quantification of CMD. It evaluates the clinical utility, strengths and limitation of these imaging modalities in diagnosing and managing CMD. Having improved our understanding of CMD pathophysiology, cardiac imaging can provide insights into its prognosis and enhance diagnostic accuracy. Continued innovation in imaging technologies is essential for advancing knowledge about CMD, leading to improved cardiovascular outcomes and patient care.

Mapping the knowledge of omics in myocardial infarction: A scientometric analysis in R Studio, VOSviewer, Citespace, and SciMAT

Many researchers nowadays choose multi-omics techniques for myocardial infarction studies. However, there's yet to be a review article integrating myocardial infarction multi-omics. Hence, this study adopts the popular bibliometrics. Based on its principles, we use software like R Studio, Vosviewer, Citespace, and SciMAT to analyze literature data of myocardial infarction omics research (1991-2022) from Web of Science. By extracting key information and calculating weights, we conduct analyses from 4 aspects: Collaboration Network Analysis, Co-word Analysis, Citing and Cited Journal Analysis, and Co-citation and Clustering Analysis, aiming to understand the field's cooperation, research topic evolution, and knowledge flow. The results show that myocardial infarction omics research is still in its early stage with limited international cooperation. In terms of knowledge flow, there's no significant difference within the discipline, but non-biomedical disciplines have joined, indicating an interdisciplinary integration trend. In the overall research field, genomics remains the main topic with many breakthroughs identifying susceptibility sites. Meanwhile, other omics fields like lipidomics and proteomics are also progressing, clarifying the pathogenesis. The cooperation details in this article enable researchers to connect with others, facilitating their research. The evolution trend of subject terms helps them set goals and directions, quickly grasp the development context, and read relevant literature. Journal analysis offers submission suggestions, and the analysis of research base and frontier provides references for the research's future development.

Emerging Imaging Techniques for Atherosclerosis in Systemic Immune-Mediated Inflammatory Conditions

Atherosclerosis affects patients with systemic immune-mediated inflammatory diseases at an increased rate compared with the general population. In recent years, our understanding of the pathophysiology of atherosclerosis has advanced considerably. Nevertheless, cardiovascular imaging modalities that can adequately assess the biological background of atherosclerosis have not reached widespread clinical adoption. Novel developments in cardiac imaging have the potential to enhance the diagnostic yield of these modalities further while providing essential insights into the anatomy, composition, and biology of atherosclerotic lesions. In this review, we highlight some of the latest developments in the field for the evaluation of atherosclerosis using advances in echocardiography, computed tomography, positron emission tomography, and cardiovascular magnetic resonance. Additionally, we discuss evidence specifically in patients with immune-mediated inflammatory diseases and outline unmet research needs for future development.

Myocardial contrast echocardiography evaluation of coronary microvascular dysfunction to Predict MACEs in patients with heart failure with preserved ejection fraction follow-up

BACKGROUND

CMD refers to the abnormalities of the tiny arteries and capillaries within the coronary artery system, which result in restricted or abnormal blood flow. CMD is an important mechanism involved in ischemic heart disease and secondary heart failure. CMD can explain left ventricular dysfunction and poor prognosis.The European Association of Cardiovascular Imaging recommends the use of MCE for the assessment of myocardial perfusion. Myocardial contrast echocardiography (MCE) is used to evaluate the accuracy of Coronary microvascular dysfunction (CMD) for predicting major adverse cardiac events (MACEs) in patients with heart failure with preserved ejection fraction (HFpEF) at follow-up.

METHODS

The clinical data of 142 patients diagnosed with HFpEF in our hospital from January 2020 to January 2022 were retrospectively summarized and stratified into 77 cases (> 1) in the CMD group and 65 cases (= 1) in the non-CMD group based on the perfusion score index (PSI) of the 17 segments of the left ventricle examined by the admission MCE, and the perfusion parameters were measured at the same time, including the peak plateau intensity (A value), the curve slope of the curve rise (βvalue) and A × β values. At a median follow-up of 27 months till October 2023, MACEs were recorded mainly including heart failure exacerbation, revascularization, cardiac death, etc. RESULTS: Increasing age, hypertension, diabetes, and coronary artery disease in the CMD group resulted in decreased left ventricular ejection fraction (LVEF), increased plasma NT-B-type natriuretic peptide (BNP) and left ventricular global longitudinal strain (LVGLS), decreased A-values and A × β-values, and an increased incidence of MACEs (P < 0.05). Univariate and multivariate Cox regression analyses showed that LVGLS (HR = 1.714, 95% CI = 1.289-2.279, P < 0.001) and A × β values (HR = 0.636, 95% CI = 0.417 to 0.969, P = 0.035) were independent predictors of MACEs in patients with HFpEF. The receiver operating characteristic curve (ROC) showed that the area under the curve (AUC) of LVGLS combined with A × β value for diagnosis of MACEs was 0.861 (95% CI = 0.761 ~ 0.961, P < 0.001), which was significantly higher than that of LVGLS or A × β value (P < 0.05). The Kaplan-Meier survival curves showed that the cumulative survival rate in CMD group was significantly lower than non-CMD group (logrank χ2 = 6.626, P = 0.010), with the most significant difference at 20 months of follow-up.

CONCLUSION

MCE can evaluate CMD semi-quantitatively and quantitatively, LVGLS combined with A × β value has good performance in predicting the risk of developing MACEs in patients with HFpEF at 3 years of follow-up, and CMD can be used as an important non-invasive indicator for assessing clinical prognosis.

Effect of quantitative parameters of contrast-enhanced ultrasound on the long-term prognosis of patients with chronic coronary syndrome

Background

Ultrasound is one of the most commonly used examination methods in patients with coronary artery disease (CAD) and is valuable in evaluating patient prognosis. Although contrast-enhanced ultrasound (CEUS) can assess more in depth the vascular lesions of patients, there is still a lack of relevant research on the value of quantitative parameters of CEUS in predicting the long-term prognosis of patients with chronic coronary syndrome (CCS), thus, we designed this study.

Methods

From January 2016 to December 2017, a total of 473 patients with CCS admitted to Yueyang People's Hospital were retrospectively enrolled. The patients were followed up for five years. According to whether the patients had major adverse cardiovascular events (MACE), patients were divided into the MACE group (n=113) and the control group (n=360). The CEUS was performed to detect the myocardial perfusion status. The value of quantitative parameters of CEUS in predicting the MACE in patients with CCS was analyzed using the receiver operating characteristic (ROC) curve.

Results

Peak intensity of contrast agent at platform stage, rising rate of microbubble reperfusion, and left ventricular ejection fraction (LVEF) were found to be valuable in predicting the risk of MACE in patients with CCS. Among them, the peak intensity of contrast agent at platform stage had the highest predictive value, and the area under the curve (AUC) was 0.860 [95% confidence interval (CI): 0.827-0.894, P<0.001]. Multivariate logistics regression analysis showed that the peak intensity of contrast agent at platform stage <4.54 dB and rising rate of microbubble reperfusion <0.275 s were independent risk factors of MACE in patients with CCS. The relative risks were 12.238 (95% CI: 6.632-22.585) and 5.724 (95% CI: 3.149-10.405), respectively.

Conclusions

Quantitative parameters of CEUS can be used as predictors of MACE in patients with CCS, and strengthening the management of such high-risk patients may be beneficial to reduce the incidence of MACE.

Progress in molecular mechanisms of coronary microvascular dysfunction

Coronary microvascular dysfunction is a high-risk factor for many cardiovascular events. However, because of multiple risk factors and limited understanding about its underlying pathophysiological mechanisms, it was easily misdiagnosed. Therefore, its clinical diagnosis and treatment were greatly restricted. Coronary microcirculation refers to microvessels that play an important role in the physiological regulation of myocardial perfusion and regulating blood flow distribution, fulfilling myocardial metabolic needs and moderating peripheral vascular resistance. In coronary microvascular dysfunction, vascular endothelial celldamage is a critical link. The main feature of early coronary microvascular dysfunction is the impairment of endothelial cell proliferation, adhesion, migration, apoptosis, and secretion. Moreover, coronary microvascular dysfunction risk factors include hyperglycemia, lipid metabolism disorders, ischemia-reperfusion injury, aging, and hypertension, similar to coronary atherosclerosis. There are various mechanisms by which these risk factors harm endothelial function and cause microcirculatory disturbances. Therefore, we reviewed coronary microvascular dysfunction's risk factors and pathogenesis in this article.

Unveiling the Enigma: Exploring the Intricate Link Between Coronary Microvascular Dysfunction and Takotsubo Cardiomyopathy

This review article delves into the intricate and evolving relationship between coronary microvascular dysfunction (CMD) and takotsubo cardiomyopathy (TCM), two intriguing cardiovascular conditions increasingly recognised for their potential interplay. We examine their characteristics, shared pathophysiological mechanisms, diagnostic challenges, and management strategies. Emerging evidence suggests a link between microvascular dysfunction and the development of TCM, leading to a deeper exploration of their connection. Accurate diagnosis of both conditions becomes essential, as microvascular dysfunction may modify TCM outcomes. We underscore the significance of understanding this connection for improved patient care, emphasising the need for tailored interventions when CMD and TCM coexist. Collaborative research and heightened clinical awareness are advocated to advance our comprehension of this relationship. Through interdisciplinary efforts, we aim to refine diagnostic precision, develop targeted therapies, and enhance patient outcomes in cardiovascular medicine.

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

Background

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).

Materials and methods

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.

Results

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.

Conclusions

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.

Early diagnosis of coronary microvascular dysfunction by myocardial contrast stress echocardiography

Coronary microvascular dysfunction (CMD) is one of the basic mechanisms of myocardial ischemia. Myocardial contrast echocardiography (MCE) is a bedside technique that utilises microbubbles which remain entirely within the intravascular space and denotes the status of microvascular perfusion within that region. Some pilot studies suggested that MCE may be used to diagnose CMD, but without further validation. This study is aimed to investigate the diagnostic performance of MCE for the evaluation of CMD. MCE was performed at rest and during adenosine triphosphate stress. ECG triggered real-time frames were acquired in the apical 4-chamber, 3-chamber, 2-chamber, and long-axis imaging planes. These images were imported into Narnar for further processing. Eighty-two participants with suspicion of coronary disease and absence of significant epicardial lesions were prospectively investigated. Thermodilution was used as the gold standard to diagnose CMD. CMD was present in 23 (28%) patients. Myocardial blood flow reserve (MBF) was assessed using MCE. CMD was defined as MBF reserve < 2. The MCE method had a high sensitivity (88.1%) and specificity (95.7%) in the diagnosis of CMD. There was strong agreement with thermodilution (Kappa coefficient was 0.727; 95% CI: 0.57-0.88, p < 0.001). However, the correlation coefficient (r = 0.376; p < 0.001) was not high.