Treatment of coronary microvascular dysfunction

Single nucleotide polymorphisms: Implications in the early diagnosis and targeted intervention of coronary microvascular dysfunction

Coronary microvascular dysfunction (CMD) is a clinical syndrome of myocardial ischemia caused by structural and/or functional abnormalities of pre-coronary arterioles and arterioles. While genetics and other factors play a role in CMD etiology, the key pathogenic mechanism remains unclear. Currently, the diagnostic procedure for CMD is still cumbersome, and there is a lack of effective targeted interventions. Single nucleotide polymorphisms (SNPs) offer promise in addressing these issues. SNPs, reflecting common genetic variations, have garnered extensive investigation across multiple diseases. Several SNPs associated with CMD have been discovered, and some have the potential to be therapeutic targets. Nevertheless, studies on CMD-related SNPs are relatively nascent and limited in number. In this review, we summarize the previously reported CMD-associated SNPs, delineate their pathophysiological mechanisms, and predict potentially important CMD sites by analyzing the SNPs linked to diseases sharing similar pathogenetic mechanisms and risk factors, such as coronary artery disease. We aim to explore reliable genetic markers implicated in CMD risk and prognosis, thereby providing a novel approach for early diagnosis and gene-targeted interventions of CMD in subsequent studies.

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.

Rationale and design of the Women's Ischemia Syndrome Evaluation Mechanisms of Coronary Microvascular Dysfunction Leading to Pre-Heart Failure With Preserved Ejection Fraction (WISE Pre-HFpEF)

BACKGROUND

There is increasing recognition that the pathophysiology of coronary microvascular dysfunction (CMD) plays a pivotal role in the development of heart failure with preserved ejection fraction (HFpEF). However, the mechanisms underlying this role are not known.

STUDY DESIGN AND METHODS

The Women's Ischemia Syndrome Evaluation Mechanisms of Coronary Microvascular Dysfunction Leading to Pre-Heart Failure With Preserved Ejection Fraction (WISE Pre-HFpEF) is a prospective cohort study enrolling 180 women and men undergoing clinically indicated invasive coronary angiography for suspected ischemia with no obstructive coronary artery disease. The study aims to investigate (i) CMD-related ischemia contribution to myocellular damage and impaired left ventricular (LV) relaxation as determined invasively by ultra-high sensitivity cardiac troponin I (u-hs-cTnI) measurements in the coronary sinus/great cardiac vein and LV pressure-volume loops, respectively, during provocative stress testing with isometric handgrip, and (ii) CMD-related ischemic myocellular damage contribution to LV diastolic dysfunction progression as assessed using cardiac magnetic resonance imaging obtained at enrollment and 1-2 years later, along with prospectively repeated ambulatory u-hs-cTnI measurements.

CONCLUSIONS

The WISE pre-HFpEF study is designed to investigate whether ischemic myocardial damage secondary to CMD contributes to the progression of LV diastolic dysfunction. The findings from this study will provide new understanding of the role of CMD in HFpEF development as well as the potential benefits of CMD-directed therapies for the prevention and treatment of HFpEF.

TRIAL REGISTRATION

ClilicalTrial.gov, NCT03876223.

Efficacy and safety of Shexiang Baoxin Pill in patients with angina and non-obstructive coronary arteries: A multicenter, randomized, double-blind, placebo-controlled, phase Ⅳ clinical trial

INTRODUCTION

Solid evidence generated from large studies supporting the recommendation of Shexiang Baoxin Pill (MUSKARDIA) as a promising treatment for angina and nonobstructive coronary arteries (ANOCA) populations is lacking.

OBJECTIVE

To evaluate the efficacy and safety of MUSKARDIA in patients with ANOCA.

METHODS

In this randomized, double-blind, placebo-controlled, phase IV trial, we enrolled 239 patients with ANOCA at 11 centers across China between May 2021 and July 2023. Patients were randomly assigned in a 1:1 ratio to receive MUSKARDIA or placebo (orally 4 pills thrice daily) based on conventional treatment for 12 weeks. The primary endpoint was the change in angina-related outcomes, assessed using the Seattle Angina Questionnaire (SAQ) scores for the treatment groups at week 12.

RESULTS

Among 239 randomized patients with ANOCA, 236 (MUSKARDIA group, n = 117; placebo group, n = 119) completed treatment and endpoint assessments. At week 12, patients in the MUSKARDIA group showed better angina-related outcomes, with a more rapid increase in SAQ scores, than those in the placebo group (all p < 0.0001). Statistically significant differences favoring MUSKARDIA over placebo were observed for change in angina attack frequency compared with baseline at week 12 (p < 0.0001). Meanwhile, according to the Canadian Cardiovascular Society grading of angina, the change in angina pectoris severity, compared with baseline, was significantly reduced in MUSKARDIA group compared with placebo group at week 12 (p < 0.0001). The percentage of patients who did not use sublingual nitroglycerin was noticeably higher in MUSKARDIA group than that in placebo group (84.16 % vs. 58.33 %; p < 0.001). The incidence of adverse events did not differ significantly between the two groups, and no serious adverse events occurred.

CONCLUSION

This randomized, placebo-controlled clinical trial firstly confirmed that MUSKARDIA was an effective, safe, and well-tolerated treatment for patients with ANOCA in clinical settings. This study was registered at ClinicalTrials.gov (NCT04897126).

ANOCA, INOCA, MINOCA: The New Frontier of Coronary Syndromes

The growing prevalence in the diagnosis of INOCA (Ischemia with Non-Obstructive Coronary Arteries), ANOCA (Angina with Non-Obstructive Coronary Arteries), and MINOCA (Myocardial Infarction with Non-Obstructive Coronary Arteries) highlights the need to reassess their clinical relevance. Historically regarded as benign syndromes, emerging evidence suggests that these conditions may cause serious cardiovascular events and considerable long-term disability. Additionally, emerging studies suggest that non-obstructive coronary artery disease (CAD) may have a higher prevalence compared to traditional obstructive forms of CAD. This leads to the need to better clarify the underlying pathogenic mechanisms as well as the risk factors associated with these syndromes. This is precisely the aim of this review, which focuses on the complex and heterogeneous mechanisms underlying these syndromes as well as the associated risk factors. This review also sums up the diagnostic steps necessary to achieve an accurate diagnosis, along with the interventional and pharmacological approaches to be implemented in light of the latest evidence.

Ischemic Myocardium Targeting Peptide-Guided Nanobubbles for Multimodal Imaging and Treatment of Coronary Microvascular Dysfunction

Coronary microvascular dysfunction (CMD) refers to clinical symptoms caused by structural and functional damage to coronary microcirculation. The timely and precise diagnosis of CMD-related myocardial ischemia is essential for improving patient prognosis. This study describes a method for the multimodal (fluorescence, ultrasonic, and photoacoustic) noninvasive imaging and treatment of CMD based on ischemic myocardium-targeting peptide (IMTP)-guided nanobubbles functionalized with indocyanine green (IMTP/ICG NBs) and characterizes their basic characteristics and in vitro imaging and targeting abilities. The IMTP/ICG NBs enable the accurate location of myocardial ischemia via photoacoustic imaging, and when loaded with tannic acid (TA), can be used to effectively treat myocardial ischemia and fibrosis in CMD mice, achieving an effect superior to that of free TA. The origin of this high therapeutic efficiency is revealed by transcriptomic and proteomic analyses. This investigation lays the groundwork for visual monitoring and the drug-targeted treatment of CMD.

Coronary microvascular dysfunction and inflammation: Insights from the Coronary Microvascular Disease Registry

BACKGROUND

Coronary microvascular dysfunction (CMD) is associated with various inflammatory conditions that worsen endothelial dysfunction. This study aimed to investigate the relationship between CMD and inflammation using common inflammatory markers derived from complete blood count (CBC) analysis.

METHODS

Information was gathered from the Coronary Microvascular Disease Registry to examine the neutrophil-to-lymphocyte ratio (NLR), eosinophil-to-monocyte ratio (EMR), and monocyte-to-high-density lipoprotein ratio (MHR) in a cohort of patients with angina who showed non-obstructive coronary arteries and underwent invasive physiological assessments for CMD.

RESULTS

Of the 171 patients studied, 126 were CMD-negative and 45 were CMD-positive, constituting two groups of interest. The average age of all patients was 61.7 ± 11.1 years, and 63.7 % were female. No significant differences were observed between the two groups in terms of baseline characteristics, cardiovascular risk factors, or potential anti-inflammatory medications. Furthermore, there were no statistically significant differences in NLR (2.54 ± 3.71 vs. 2.52 ± 2.28, p = 0.97), EMR (0.3 ± 0.21 vs. 0.34 ± 0.29, p = 0.31), or MHR (0.02 ± 0.01 vs. 0.01 ± 0.01, p = 0.54) between CMD-positive and CMD-negative patients.

CONCLUSION

Our findings did not show a noteworthy connection between CMD and inflammation, as suggested by various simple CBC-based biomarkers.

Astragaloside IV alleviates inflammation and improves myocardial metabolism in heart failure mice with preserved ejection fraction

Background

Heart failure with preserved ejection fraction (HFpEF) has grown to become the dominant form of heart failure worldwide. However, no unequivocally effective treatment for HFpEF has been identified in clinical trials. In this study, we report that Astragaloside IV (AS-IV) can be used to treat HFpEF.

Methods

Mice were fed on a high-fat diet and given 0.5 g/L L-NAME (in drinking water) for 10 weeks to establish the HFpEF model. After 10th weeks, the HFpEF mice were given 10 mg/kg empagliflozin, 10 mg/kg AS-IV, or 20 mg/kg AS-IV for 4 weeks. The echocardiography, blood pressure, hemodynamics, heart failure biomarkers, collagen deposition and fibrosis, histopathology, and inflammation in HFpEF mice were evaluated. Metabolic profiling based on NMR measurements was also performed. Myocardial glucose and fatty acid metabolism were evaluated.

Results

AS-IV improves cardiac function and myocardial remodeling in HFpEF mice. AS-IV attenuates systemic inflammatory infiltration and myocardial inflammation levels in HFpEF mice by decreasing the expression of plasma inflammatory markers GDF15, CRP, IL1RL1, and MCP-1, NLRP3, IL-1β, Caspase-1, and IL-6 in the myocardium of HFpEF mice. Metabolomic analysis suggested that AS-IV improved cardiac glucose and fatty acid metabolism in HFpEF mice. Further studies showed that AS-IV significantly improved Complex I activity, increased ATP production, and elevated plasma NAD + levels; AS-IV also significantly improved pyruvate dehydrogenase activity and decreased pyruvate and lactate accumulation, thereby improving glucose metabolism in the hearts of HFpEF mice.

Conclusion

These results provide novel evidence that Astragaloside IV alleviates inflammation and improves myocardial metabolism in HFpEF mice.

[Explorative Exmination of Coronary Microcirculatory Ischemia in Type 2 Diabetes Mellitus Patients With One-Stop Cardiac Computed Tomography]

Objective

To analyze the differences in computed tomography (CT) myocardial perfusion parameters between type 2 diabetes mellitus (T2DM) patients and nondiabetic patients diagnosed with non-obstructive coronary artery disease (CAD), using a one-stop cardiac CT scanning protocol that combines coronary CT angiography (CCTA) with dynamic CT myocardial perfusion imaging (CT-MPI). In addition, we investigated the effect of T2DM on coronary microcirculatory ischemia.

Methods

After balancing the baseline levels with propensity score matching, 92 T2DM patients (the T2DM group) and 92 nondiabetic patients (the nondiabetic group) with non-obstructive CAD were enrolled eventually. The clinical characteristics and the CCTA and CT-MPI results of the two groups were compared. A directed acyclic graph was used to analyze the causal relationships between the variables and to identify key confounding factors. A multivariable regression model was established to evaluate the independent effect of T2DM on the occurrence of coronary microcirculatory ischemia after adjusting for confounding factors.

Results

There were no statistically significant differences between the T2DM group and the nondiabetic group in terms of age, sex, hypertension, hyperlipidemia, smoking history, body mass index, chest symptoms, calcium score, CAD-reporting and data system (CAD-RADS) score, and radiation dose. In the T2DM group, the mean values of myocardial blood flow (MBF) were significantly reduced both globally and in all myocardial segments (basal, mid, and apical segments) compared to those of the nondiabetic group (P<0.05). Furthermore, the incidence of coronary microcirculatory ischemia in the T2DM group was significantly higher than that in the nondiabetic group (21.7% [20/92] vs. 5.4% [5/92], P=0.01). Multivariable logistic regression analysis showed that T2DM was an important independent risk factor for coronary microcirculatory ischemia (odds ratio=5.095, 95% confidence interval: 1.753-14.805).

Conclusion

According to our assessment with a one-stop cardiac CT scanning protocol combining CCTA and dynamic CT-MPI, patients with non-obstructive CAD and T2DM have reduced global MBF, which makes them more prone to coronary microcirculatory ischemia. Furthermore, T2DM is independently associated with coronary microcirculatory ischemia.

The effectiveness of vasodilators on chronic obstructive pulmonary disease: A systematic review and meta-analysis

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a complex progressive disease. Some vasodilators have been reported with therapeutic potential to protect vascular function therefore may delay the progression of COPD.

METHODS

We searched PubMed, Embase, Cochrane Library, Web of Science, OVID and Clinicaltrials.gov database for eligible randomized controlled trials (RCTs) published before January 1, 2024. RCTs which treatment with vasodilators to COPD patients were included. Gas-blood exchange indicators were the primary outcomes, and ventilation function and quality of life indicators were the secondary outcomes. Mean differences with 95% confidence intervals were extracted. Subgroup analysis of vasodilator category and COPD complicated with or without pulmonary hypertension (PH) were performed. The risk of bias was assessed using Cochrane risk of bias tool, and the meta-analysis was conducted.

RESULTS

Twenty studies with a total sample size of 986 were included. The results showed that the 2 types of drugs in vasodilators included PDE-5 inhibitors could improve DLCO (MD = 6.56 [95% CI (1.74, 11.39)], P = .008) and iNO could reduce PaCO2 (MD = -0.10 [95% CI (-0.17, -0.03)], P = .006). Vasodilators could reduce PaCO2 in COPD complicated with PH (COPD-PH) (MD = -0.10 [95% CI (-0.17, -0.03)], P = .006). There were no statistically significant differences in FEV1 (MD = 0.02 [95% CI (-0.11, 0.16)], P = .74), FEV1% predicted (MD = 0.07 [95% CI (-1.90, 2.05)], P = .94), FEV1/FVC (MD = 0.70 [95% CI (-4.02, 5.42)], P = .77) and VE/VCO2 (MD = -0.17 [95% CI (-2.39, 2.05)], P = .88) levels. The total SGRQ score was significantly lower in vasodilator groups (MD = -5.53 [95% CI (-9.81, -1.24)], P = .01).

CONCLUSIONS

The therapeutic effects of vasodilators for COPD are controversial. In this meta-analysis, vasodilators have benefits in improving gas-blood exchange function and quality of life in COPD patients. However, vasodilators may have a limited capacity to improve pulmonary function.

Effects of statins in patients with coronary artery spasm: A nationwide population-based study

Controversies regarding the benefits of statin treatment on clinical outcomes in coronary artery spasm (CAS) without obstructive coronary artery disease (CAD) persist due to limited data. In this retrospective nationwide population-based cohort study from the Taiwan National Health Insurance Research Database during the period 2000-2012, the matched cohorts consisted of 12,000 patients with CAS. After propensity score matching with 1:1 ratio, 2216 patients were eligible for outcome analysis in either statin or nonstatin group, with the mean follow-up duration of 4.8 and 4.6 years, respectively. Statin users versus nonusers had a significantly reduced risk of major adverse cardiovascular events (MACEs) (6.7% vs. 9.5%, hazard ratio [HR] 0.68; 95% confidence interval [CI] 0.55-0.84) and all-cause mortality (6.0% vs. 7.6%; HR 0.77; 95% CI 0.61-0.96). While the results of MACEs were mainly contributed by cardiovascular death (1.9% vs. 3.2%; HR 0.56; 95% CI 0.38-0.83) and ischemic stroke (3.8% vs. 5.4%; subdistribution HR 0.69; 95% CI 0.52-0.91), they were primarily driven by reductions in ischemic but not hemorrhagic stroke. The benefit of statins was significantly pronounced in patients with hypertension and diabetes. Nevertheless, the effect on MACEs was consistent irrespective of age, sex, dyslipidemia, and mental disorder. Statins significantly reduced the risk of MACEs and all-cause mortality in CAS patients. The benefit of statin therapy in reducing MACEs appeared to be linear, with greater risk reduction with higher doses and longer duration without upper threshold, reflecting the dose-dependent relationship of statins with MACEs in CAS patients.

Metabolic and Proteomic Profiling of Coronary Microvascular Dysfunction: Insights from Rat Models

Coronary microvascular dysfunction (CMD) represents a principal etiological factor in ischemic heart disease. Nonetheless, a considerable subset of CMD patients experiences diagnostic delays attributable to the inadequacy of current diagnostic methodologies; which in turn results in deferred therapeutic interventions and elevated mortality rates. This study seeks to elucidate the distinct metabolic profile associated with CMD in rat models and to identify specific diagnostic markers that could enhance the diagnostic accuracy for CMD. In this study, 18 Wistar rats were randomly allocated into two groups: the sham group and the CMD group. The CMD group received injections of embolic microspheres into the left ventricle to establish a CMD model. Subsequently, non-targeted metabolomics and acetylated proteomics analyses were conducted. Machine-learning techniques were employed to identify the co-diagnostic markers of the disease. This study identified 53 key proteins through differential expression proteins (DEPs) and modular proteins analysis. Subsequently, four core proteins (Emc1; Ank1; Fbln2; and Hp) were determined as diagnostic markers for CMD using lasso regression, support vector machine, and random forest methodologies. Receiver operating characteristic curve analysis further demonstrated robust diagnostic performance. Gene ontology and kyoto encyclopedia of genes and genome enrichment analyses indicated that the DEPs were predominantly associated with metabolic pathways. Ultimately, the integrative analysis of proteomics and metabolomics suggested that the central metabolic mechanism underlying CMD pathogenesis may be linked to the tricarboxylic acid cycle. This study revealed specific changes in the proteomic and metabolic profiles of CMD rats and identified four diagnostic markers, which are proteins and metabolites that could be potential diagnostic biomarkers for CMD.

Comparing planned versus ad hoc coronary microvascular assessment: Early findings from the Coronary Microvascular Disease Registry

BACKGROUND

Coronary microvascular dysfunction (CMD) is an etiology for angina with non-obstructive coronary disease. However, the initial adoption of CMD assessment, whether planned or conducted ad hoc, is limited. We characterize planned and ad hoc CMD assessments and highlight evolving trends of a CMD referral center.

METHODS

We analyzed outpatient data from the Coronary Microvascular Disease Registry from 2021 to 2023. Patients were categorized into planned or ad hoc CMD assessment groups, and baseline characteristics, hospital stay, medications, and physiological measurements were compared. Secondary analysis evaluated a CMD referral center's evolution.

RESULTS

Of 101 included outpatients, 67.3 % underwent ad hoc procedures and 32.7 % planned procedures. Average age was 63.1 ± 10.1 years. The planned procedure group was 87.9 % female, and the ad hoc procedure group was 51.5 % female. There were no significant differences in index of microvascular resistance or coronary flow reserve between groups. Hospital stay duration was <1 day for both groups, and neither reported complications. Ad hoc patients were more frequently prescribed aspirin before (64.7 % vs. 36.4 %, p = 0.007) and after the procedure (66.2 % vs. 39.4 %, p = 0.01). CMD rates were higher for planned procedures (30.3 % vs. 10.3 %, p = 0.01). We observed that CMD referral centers have more planned procedures and a higher rate of positive results over time.

CONCLUSION

CMD referral centers' planned procedures, and subsequent positive cases, increased over time. This emphasizes the importance of planned procedures, appropriate patient selection, and increased awareness of CMD among healthcare providers.

CLINICAL TRIAL REGISTRATION

Coronary Microvascular Disease (CMD) Registry, NCT05960474, https://clinicaltrials.gov/study/NCT05960474.

Methylglyoxal induces endothelial cell apoptosis and coronary microvascular dysfunction through regulating AR-cPLA2 signaling

OBJECTIVE

Since diabetic patients with coronary microvascular dysfunction (CMD) exhibit high cardiac mortality and women have higher prevalence of non-obstructive coronary artery disease than men, we tried to expand the limited understanding about the etiology and the sex difference of diabetic CMD.

APPROACH AND RESULTS

Accumulated methylglyoxal (MGO) due to diabetes promotes vascular damage and it was used for mimicking diabetic status. Flow cytometry analysis and isometric tension measurement were performed to evaluate coronary artery endothelial injury. MGO induced apoptosis of coronary endothelial cells, accompanied by downregulation of androgen receptor (AR). Lentivirus-mediated stable expression of AR in coronary endothelial cells increased anti-apoptotic Bcl-2 expression and attenuated MGO-induced cell apoptosis. cPLA2 activation was the downstream of AR downregulation by MGO treatment. Moreover, MGO also activated cPLA2 rapidly to impair endothelium-dependent vasodilation of coronary arteries from mice. Reactive oxygen species (ROS) overproduction was demonstrated to account for MGO-mediated cPLA2 activation and endothelial dysfunction. Importantly, AR blockade increased endothelial ROS production whereas AR activation protected coronary artery endothelial vasodilatory function from the MGO-induced injury. Although galectin-3 upregulation was confirmed by siRNA knockdown in endothelial cells not to participate in MGO-induced endothelial apoptosis, pharmacological inhibitor of galectin-3 further enhanced MGO-triggered ROS generation and coronary artery endothelial impairment.

CONCLUSIONS

Our data proposed the AR downregulation-ROS overproduction-cPLA2 activation pathway as one of the mechanisms underlying diabetic CMD and postulated a possible reason for the sex difference of CMD-related angina. Meanwhile, MGO-induced galectin-3 activation played a compensatory role against coronary endothelial dysfunction.

Coronary microvascular disease in women: epidemiology, mechanisms, evaluation, and treatment

Coronary microvascular dysfunction (CMD) involves functional or structural abnormalities of the coronary microvasculature resulting in dysregulation of coronary blood flow (CBF) in response to myocardial oxygen demand. This perfusion mismatch causes myocardial ischemia, which manifests in patients as microvascular angina (MVA). CMD can be diagnosed non-invasively via multiple imaging techniques or invasively using coronary function testing (CFT), which assists in determining the specific mechanisms involving endothelium-independent and dependent epicardial and microcirculation domains. Unlike traditional coronary artery disease (CAD), CMD can often occur in patients without obstructive atherosclerotic epicardial disease, which can make the diagnosis of CMD difficult. Moreover, MVA due to CMD is more prevalent in women and carries increased risk of future cardiovascular events. Successful treatment of symptomatic CMD is often patient-specific risk factor and endotype targeted. This article aims to review newly identified mechanisms and novel treatment strategies for managing CMD, and outline sex-specific differences in the presentation and pathophysiology of the disease.

Establishing the longitudinal hemodynamic mapping framework for wearable-driven coronary digital twins

Understanding the evolving nature of coronary hemodynamics is crucial for early disease detection and monitoring progression. We require digital twins that mimic a patient's circulatory system by integrating continuous physiological data and computing hemodynamic patterns over months. Current models match clinical flow measurements but are limited to single heartbeats. To this end, we introduced the longitudinal hemodynamic mapping framework (LHMF), designed to tackle critical challenges: (1) computational intractability of explicit methods; (2) boundary conditions reflecting varying activity states; and (3) accessible computing resources for clinical translation. We show negligible error (0.0002-0.004%) between LHMF and explicit data of 750 heartbeats. We deployed LHMF across traditional and cloud-based platforms, demonstrating high-throughput simulations on heterogeneous systems. Additionally, we established LHMFC, where hemodynamically similar heartbeats are clustered to avoid redundant simulations, accurately reconstructing longitudinal hemodynamic maps (LHMs). This study captured 3D hemodynamics over 4.5 million heartbeats, paving the way for cardiovascular digital twins.

Novel diagnostic approaches and management of coronary microvascular dysfunction

The mechanism underlying ischaemic heart disease (IHD) has been primarily attributed to obstructive coronary artery disease (CAD). However, non-obstructive coronary arteries are identified in >50% of patients undergoing elective coronary angiography, recently leading to growing interest in the investigation and management of angina/ischaemia with non-obstructive coronary arteries (ANOCA/INOCA). INOCA is an umbrella term encompassing a multiple spectrum of possible pathogenetic entities, including coronary vasomotor disorders which consist of two major endotypes: coronary microvascular dysfunction (CMD) and vasospastic angina. Both conditions can coexist and be associated with concomitant obstructive CAD. Particularly, CMD refers to myocardial ischaemia due to reduced vasodilatory capacity of coronary microcirculation secondary to structural remodelling or impaired resting microvascular tone (functional) or a combination of both. CMD is not a benign condition and is more prevalent in women presenting with chronic coronary syndrome compared to men. In this setting, an impaired coronary flow reserve has been associated with increased risk of major adverse cardiovascular events. ANOCA/INOCA patients also experience impaired quality of life and associated increased healthcare costs. Therefore, research in this scenario has led to better definition, classification, and prognostic stratification based on the underlying pathophysiological mechanisms. The development and validation of non-invasive imaging modalities, invasive coronary vasomotor function testing and angiography-derived indices provide a comprehensive characterisation of CMD. The present narrative review aims to summarise current data relating to the diagnostic approach to CMD and provides details on the sequence that therapeutic management should follow.

Optimizing Management of Stable Angina: A Patient-Centered Approach Integrating Revascularization, Medical Therapy, and Lifestyle Interventions

Angina pectoris may arise from obstructive coronary artery disease (CAD) or in the absence of significant CAD (ischemia with nonobstructed coronary arteries [INOCA]). Therapeutic strategies for patients with angina and obstructive CAD focus on reducing cardiovascular events and relieving symptoms, whereas in INOCA the focus shifts toward managing functional alterations of the coronary circulation. In obstructive CAD, coronary revascularization might improve angina status, although a significant percentage of patients present angina persistence or recurrence, suggesting the presence of functional mechanisms along with epicardial CAD. In patients with INOCA, performing a precise endotype diagnosis is crucial to allow a tailored therapy targeted toward the specific pathogenic mechanism. In this expert opinion paper, we review the evidence for the management of angina, highlighting the complementary role of coronary revascularization, optimal medical therapy, and lifestyle interventions and underscoring the importance of a personalized approach that targets the underlying pathobiology.

Emerging Pathway to a Precision Medicine Approach for Angina With Nonobstructive Coronary Arteries in Women

Women are disproportionately affected by symptoms of angina with nonobstructive coronary arteries (ANOCA) which is associated with significant mortality and economic impact. Although distinct endotypes of ANOCA have been defined, it is underdiagnosed and is often incompletely characterized when identified. Patients are often unresponsive to traditional therapeutic options, which are typically antianginal, and the current ability to guide treatment modification by specific pathways is limited. Studies have associated specific genetic loci, transcriptomic features, and biomarkers with ANOCA. Such panomic data, in combination with known imaging and invasive diagnostic techniques, should be utilized to define more precise pathophysiologic subtypes of ANOCA in women, which will in turn help to identify targeted, effective therapies. A precision medicine-based approach to managing ANOCA incorporating these techniques in women has the potential to significantly improve their clinical care.

Endothelial microRNAs in INOCA patients with diabetes mellitus

Ischemia with non-obstructive coronary artery (INOCA) is a common cause of hospital admissions, leading to negative outcomes and reduced quality of life. Central to its pathophysiology is endothelial dysfunction, which contributes to myocardial ischemia despite the absence of significant coronary artery blockage. Addressing endothelial dysfunction is essential in managing INOCA to alleviate symptoms and prevent cardiovascular events. Recent studies have identified diabetes mellitus (DM) as a significant factor exacerbating INOCA complications by promoting endothelial impairment and coronary microvascular dysfunction. MicroRNAs (miRNAs) have emerged as potential biomarkers and therapeutic targets in various biological processes, including endothelial dysfunction and cardiovascular diseases. However, research on miRNA biomarkers in INOCA patients is sparse. In this study, we examined a panel of circulating miRNAs involved in the regulation of endothelial function in INOCA patients with and without DM. We analyzed miRNA expression using RT-qPCR in a cohort of consecutive INOCA patients undergoing percutaneous coronary intervention. We detected a significant dysregulation of miR-363-5p and miR-92a-3p in INOCA patients with DM compared to those without DM, indicating their role as biomarkers for predicting and monitoring endothelial dysfunction in INOCA patients with DM.

Stratified medicine for acute and chronic coronary syndromes: A patient-tailored approach

The traditional approach to management of cardiovascular disease relies on grouping clinical presentations with common signs and symptoms into pre-specified disease pathways, all uniformly treated according to evidence-based guidelines ("one-size-fits-all"). The goal of precision medicine is to provide the right treatment to the right patients at the right time, combining data from time honoured sources (e.g., history, physical examination, imaging, laboratory) and those provided by multi-omics technologies. In patients with ischemic heart disease, biomarkers and intravascular assessment can be used to identify endotypes with different pathophysiology who may benefit from distinct treatments. This review discusses strategies for the application of stratified management to patients with acute and chronic coronary syndromes.

Skin sympathetic nerve activity and ST-segment depression in women

Background

ST-segment depression (ST depression) on exercise electrocardiogram (ECG) and ambulatory ECG monitoring may occur without myocardial ischemia. The mechanisms of nonischemic ST depression remain poorly understood.

Objective

The study sought to test the hypothesis that the magnitudes of skin sympathetic nerve activity (SKNA) correlate negatively with the ST-segment height (ST height) in ambulatory participants.

Methods

We used neuECG (simultaneous recording of SKNA and ECG) to measure ambulatory ST height and average SKNA (aSKNA) in 19 healthy women, 6 women with a history of Takotsubo syndrome (TTS), and 4 women with ischemia and no obstructive coronary arteries (INOCA).

Results

Baseline aSKNA was similar between healthy women, women with TTS, and women with INOCA (1.098 ± 0.291 μV, 0.980 ± 0.061 μV, and 0.919 ± 0.0397 μV, respectively; P = .22). The healthy women had only asymptomatic upsloping ST depression. All participants had a significant (P < .05) negative correlation between ST height and aSKNA. Ischemic episodes (n = 15) were identified in 2 TTS and 4 INOCA participants. The ischemic ST depression was associated with increased heart rate and elevated aSKNA compared with baseline. An analysis of SKNA burst patterns at similar heart rates revealed that SKNA total burst area was significantly higher during ischemic episodes than nonischemic episodes (0.301 ± 0.380 μV·s and 0.165 ± 0.205 μV·s; P = .023) in both the TTS and INOCA participants.

Conclusion

Asymptomatic ST depression in ambulatory women is associated with elevated SKNA. Heightened aSKNA is also noted during ischemic ST depression in women with TTS and INOCA. These findings suggest that ST segment depression is a physiological response to heightened sympathetic tone but may be aggravated by myocardial ischemia.

A Randomized Controlled Study of Enhanced External Counterpulsation with Cardiac Rehabilitation in Patients with Nonobstructive Coronary Artery Disease and Coronary Microvascular Dysfunction

Treatment with enhanced external counterpulsation (EECP) or cardiac rehabilitation (CR) benefits patients with coronary heart disease; this paper intends to explore the feasibility of EECP combined with CR in patients with nonobstructive coronary heart disease (NOCAD) and coronary microcirculation disorders (CMD).In January 2021-2022 month June our income NOCAD patients as the research object, the line of cardiac magnetic resonance (CMR), myocardial perfusion reserve (MPR) < 2.0 coronary microcirculation disorders (CMD, 80 cases). Random indicator method 80 CMD patients divided into two groups, 40 cases in each. Usual treatment group: conventional drugs and CR therapy. EECP treatment group: on the basis of standard treatment group, employ EECP therapy. Comparing the two groups before and after the treatment curative effect cardiac function index, endothelial unction index, adverse cardiovascular events, etc.After EECP treatment, the treatment group showed a higher effective rate compared to the usual treatment group (P < 0.05). EECP group curative effect, left ventricular ejection fraction,plasma NO and vascular endothelial growth factor levels higher than the usual group, the incidence of adverse cardiovascular events is lower than the usual group. The difference was statistically significant (P < 0.05).EECP combined with cardiac rehabilitation in patients with CMD symptoms has better effect and safety and provides reference for treatment of CMD patients.

Inflammation and coronary microvascular disease: relationship, mechanism and treatment

Coronary microvascular disease (CMVD) is common in patients with cardiovascular risk factors and is linked to an elevated risk of adverse cardiovascular events. Although modern medicine has made significant strides in researching CMVD, we still lack a comprehensive understanding of its pathophysiological mechanisms due to its complex and somewhat cryptic etiology. This greatly impedes the clinical diagnosis and treatment of CMVD. The primary pathological mechanisms of CMVD are structural abnormalities and/or dysfunction of coronary microvascular endothelial cells. The development of CMVD may also involve a variety of inflammatory factors through the endothelial cell injury pathway. This paper first reviews the correlation between the inflammatory response and CMVD, then summarizes the possible mechanisms of inflammatory response in CMVD, and finally categorizes the drugs used to treat CMVD based on their effect on the inflammatory response. We hope that this paper draws attention to CMVD and provides novel ideas for potential therapeutic strategies based on the inflammatory response.

Optimal Medical Therapy for Stable Ischemic Heart Disease: Focus on Anti-anginal Therapy

Chronic coronary disease (CCD) is a major cause of morbidity and mortality worldwide. The most common symptom of CCD is exertional angina pectoris, a discomfort in the chest that commonly occurs during activities of daily life. Patients are dismayed by recurring episodes of angina and seek medical help in preventing or minimizing episodes. Angina occurs when the coronary arteries are unable to supply sufficient blood flow to the cardiac muscle to meet the metabolic needs of the left ventricular myocardium. While lifestyle changes and aggressive risk factor modification play a critical role in the management of CCD, management of angina usually requires pharmacologic therapy. Medications such as beta-blockers, calcium channel blockers, nitrates, ranolazine, and others ultimately work to improve the mismatch between myocardial blood flow and metabolic demand. This manuscript briefly describes the pathophysiologic basis for symptoms of angina, and how currently available anti-anginal therapies contribute to preventing or minimize the occurrence of angina.

Coronary microvascular dysfunction assessment: A comparative analysis of procedural aspects

BACKGROUND

Full adoption of coronary microvascular dysfunction (CMD) assessment faces challenges due to its invasive nature and concerns about prolonged procedure time and increased contrast and/or radiation exposure. We compared procedural aspects of CMD invasive assessment to diagnostic left heart catheterization (DLHC) in patients with chest pain who were not found to have obstructive coronary artery disease.

METHODS

A total of 227 patients in the Coronary Microvascular Disease Registry were compared to 1592 patients who underwent DLHC from August 2021 to November 2023. The two cohorts were compared using propensity-score matching; primary outcomes were fluoroscopy time and total contrast use.

RESULTS

The participants' mean age was 64.1 ± 12.6 years. CMD-assessed patients were more likely to be female (66.5% vs. 45.2%, p < 0.001) and have hypertension (80.2% vs. 44.5%, p < 0.001), history of stroke (11.9% vs. 6.3%, p = 0.002), and history of myocardial infarction (20.3% vs. 7.7%, p < 0.001). CMD assessment was safe, without any reported adverse outcomes. A propensity-matched analysis showed that patients who underwent CMD assessment had slightly higher median contrast exposure (50 vs. 40 mL, p < 0.001), and slightly longer fluoroscopy time (6.9 vs. 4.7 min, p < 0.001). However, there was no difference in radiation dose (209.3 vs. 219 mGy, p = 0.58) and overall procedure time (31 vs. 29 min, p = 0.37).

CONCLUSION

Compared to DLHC, CMD assessment is safe and requires only slightly additional contrast use (10 mL) and slightly longer fluoroscopy time (2 min) without clinical implications. These findings emphasize the favorable safety and feasibility of invasive CMD assessment.

Targeted Therapies for Microvascular Disease

Coronary microvascular dysfunction (CMD) is a common cause of ischemia but no obstructive coronary artery disease that results in an inability of the coronary microvasculature to meet myocardial oxygen demand. CMD is challenging to diagnose and manage due to a lack of mechanistic research and targeted therapy. Recent evidence suggests we can improved patient outcomes by stratifying antianginal therapies according to the diagnosis revealed by invasive assessment of the coronary microcirculation. This review article appraises the evidence for management of CMD, which includes treatment of cardiovascular risk, antianginal therapy and therapy for atherosclerosis.

Ischemia but no obstructive coronary artery disease: more than meets the eye

Symptomatic women with angina are more likely to have ischemia with no obstructive coronary arteries (INOCA) compared to men. In both men and women, the finding of INOCA is not benign and is associated with adverse cardiovascular events, including myocardial infarction, heart failure and angina hospitalizations. Women with INOCA have more angina and a lower quality of life compared to men, but they are often falsely reassured because of a lack of obstructive coronary artery disease (CAD) and a perception of low risk. Coronary microvascular dysfunction (CMD) is a key pathophysiologic contributor to INOCA, and non-invasive imaging methods are used to detect impaired microvascular flow. Coronary vasospasm is another mechanism of INOCA, and can co-exist with CMD, but usually requires invasive coronary function testing (CFT) with provocation testing for a definitive diagnosis. In addition to traditional heart disease risk factors, inflammatory, hormonal and psychological risk factors that impact microvascular tone are implicated in INOCA. Treatment of risk factors and use of anti-atherosclerotic and anti-anginal medications offer benefit. Increasing awareness and early referral to specialized centers that focus on INOCA management can improve patient-oriented outcomes. However, large, randomized treatment trials to investigate the impact on major adverse cardiovascular events (MACE) are needed. In this focused review, we discuss the prevalence, pathophysiology, presentation, diagnosis and treatment of INOCA.

The diagnosis and treatment of women with recurrent cardiac ischemia and normal coronary arteries

Cardiac disease is the leading cause of death in women. Among women with recurrent chest pain, abnormal electrocardiograms, and/or stress tests who undergo coronary angiography, as many as 50% have normal or <50% coronary artery obstructive disease. Pharmacologic stress assessment of coronary artery flow reserve in these women frequently demonstrates an inability to increase blood flow to >2.5 times normal flow. Contributory factors include abnormal epicardial or microvascular reactivity, microvascular remodeling or rarefaction, autonomic dysfunction, or coronary plaque rupture/erosion. Assessment is necessary of serum biomarkers and coronary artery flow reserve, fractional flow reserve, microvascular resistance, and epicardial/microvascular spasm. Aggressive treatment of women with positive tests is necessary because these women have an increased incidence of recurrent chest pain, repeated hospitalizations and coronary angiograms, and cardiac death.

Shedding Light on Treatment Options for Coronary Vasomotor Disorders: A Systematic Review

PURPOSE

Coronary vasomotor dysfunction embraces two specific clinical entities: coronary (micro)vascular spasm and microvascular dysfunction. The clinical manifestations of these entities are respectively called vasospastic angina (VSA) and microvascular angina (MVA). Over the years, these diseases have become more and more prominent and several studies aimed to investigate the best diagnostic and therapeutic strategies. Patients with coronary vasomotor disorders are often undertreated due to the absence of evidence-based guidelines. The purpose of this overview is to illustrate the various therapeutic options available for the optimized management of these patients.

METHODS

A Medline search of full-text articles published in English from 1980 to April 2022 was performed. The main analyzed aspects of vasomotor disorders were treatment options. We also performed research on "Clinicaltrial.gov" for ongoing trials.

CONCLUSION

Coronary (micro)vascular spasm and microvascular dysfunction are clinical entities characterized by high prevalence and clinical representation. Several therapeutic strategies, both innovative and established, are available to optimize treatment and improve the quality of life of these patients.

Myocardial ischemia/reperfusion: Translational pathophysiology of ischemic heart disease

Ischemic heart disease is the greatest health burden and most frequent cause of death worldwide. Myocardial ischemia/reperfusion is the pathophysiological substrate of ischemic heart disease. Improvements in prevention and treatment of ischemic heart disease have reduced mortality in developed countries over the last decades, but further progress is now stagnant, and morbidity and mortality from ischemic heart disease in developing countries are increasing. Significant problems remain to be resolved and require a better pathophysiological understanding. The present review attempts to briefly summarize the state of the art in myocardial ischemia/reperfusion research, with a view on both its coronary vascular and myocardial aspects, and to define the cutting edges where further mechanistic knowledge is needed to facilitate translation to clinical practice.

Noninvasive transthoracic doppler flow velocity and invasive thermodilution to assess coronary flow reserve

Background

Coronary flow reserve (CFR) provides prognostication and coronary physiological information, including epicardial coronary stenosis and microvascular function. The relationship between stress transthoracic Doppler echocardiography (TDE)-derived coronary flow velocity reserve (CFRS-TDE) and thermodilution-derived coronary flow reserve (CFRthermo) before and after elective percutaneous coronary intervention (PCI) remains unclear.

Methods

This single-center prospective registry study evaluated patients who underwent fractional flow reserve (FFR)-guided elective PCI for left anterior descending artery (LAD) lesions with wire-based invasive physiological measurements and pre- and post-PCI stress TDE examinations.

Results

A total of 174 LAD lesions from 174 patients were included in the final analysis. A modest correlation was detected between the pre-PCI CFRS-TDE and the pre-PCI CFRthermo (r=0.383, P<0.001). The frequently used CFRS-TDE threshold of 2.0 corresponded to a pre-PCI CFRthermo of 2.18. Pre-PCI CFRS-TDE underestimated pre-PCI CFRthermo [1.89 (1.44-2.31) vs. 2.05 (1.38-2.93), P<0.001]. Both CFRS-TDE and CFRthermo increased significantly post-PCI [pre-PCI CFRS-TDE 1.89 vs. post-PCI CFRS-TDE 2.33, P<0.001; pre-PCI CFRthermo 2.05 (1.38-2.93) vs. post-PCI CFRthermo 2.59 (1.63-3.55), P<0.001]. In contrast, there was no significant relationship between changes in CFRS-TDE and changes in CFRthermo after PCI (r=0.008, P=0.915) or between post-PCI CFRS-TDE and post-PCI CFRthermo (r=0.054, P=0.482).

Conclusions

Pre-PCI CFRS-TDE and CFRthermo are modestly correlated, but post-PCI CFRS-TDE and CFRthermo have no correlation. CFRS-TDE and CFRthermo are not interchangeable, particularly post-PCI, suggesting that the two metrics represent different coronary physiologies after PCI.

Clinical aspects of ischemia with no obstructive coronary artery disease (INOCA)

Ischemia with no obstructive coronary arteries (INOCA) is defined as patients with evidence of myocardial ischemia without obstructive coronary artery disease. About 3-4 million people in the United States have INOCA, more commonly affecting women, and carries adverse morbidity, mortality, and relatively high healthcare costs. The pathophysiology of INOCA appears to be multi-factorial with a variety of contributing mechanisms. Diagnosis of INOCA is suggested by non-invasive or invasive testing consistent with myocardial ischemia. Due to the high prevalence of coronary risk factors and atherosclerosis in the INOCA population, current treatment strategies target angina, coronary atherosclerosis, and atherosclerotic risk factors, as well as burgeoning treatment of coronary microvascular dysfunction (CMD). Ongoing clinical trials are assessing different options.

Urocortin2 attenuates diabetic coronary microvascular dysfunction by regulating macrophage extracellular vesicles

Diabetic patients develop coronary microvascular dysfunction (CMD) and exhibit high mortality of coronary artery disease. Methylglyoxal (MGO) largely accumulates in the circulation due to diabetes. We addressed whether macrophages exposed to MGO exhibited damaging effect on the coronary artery and whether urocortin2 (UCN2) serve as protecting factors against such diabetes-associated complication. Type 2 diabetes was induced by high-fat diet and a single low-dose streptozotocin in mice. Small extracellular vesicles (sEV) derived from MGO-treated macrophages (MGO-sEV) were used to produce diabetes-like CMD. UCN2 was examined for a protective role against CMD. The involvement of arginase1 and IL-33 was tested by pharmacological inhibitor and IL-33-/- mice. MGO-sEV was capable of causing coronary artery endothelial dysfunction similar to that by diabetes. Immunocytochemistry studies of diabetic coronary arteries supported the transfer of arginase1 from macrophages to endothelial cells. Mechanism studies revealed arginase1 contributed to the impaired endothelium-dependent relaxation of coronary arteries in diabetic and MGO-sEV-treated mice. UCN2 significantly improved coronary artery endothelial function, and prevented MGO elevation in diabetic mice or enrichment of arginase1 in MGO-sEV. Diabetes caused a reduction of IL-33, which was also reversed by UCN2. IL-33-/- mice showed impaired endothelium-dependent relaxation of coronary arteries, which can be mitigated by arginase1 inhibition but can't be improved by UCN2 anymore, indicating the importance of restoring IL-33 for the protection against diabetic CMD by UCN2. Our data suggest that MGO-sEV induces CMD via shuttling arginase1 to coronary arteries. UCN2 is able to protect against diabetic CMD via modulating MGO-altered macrophage sEV cargoes.

Evaluation of Coronary Circulation by 13N-Ammonia Myocardial Perfusion Positron Emission Tomography in Patients with Right Coronary Artery Occlusion Due to Kawasaki Disease

BACKGROUND

Although occlusion of the right coronary artery (RCA) is common in the remote stages of Kawasaki disease, revascularization of the RCA is challenging in children and is usually managed by observation without intervention.

METHODS

Using adenosine-stress 13N-ammonia myocardial perfusion positron emission tomography, we evaluated coronary circulation in 14 patients (12 males) with RCA occlusion to identify ischemia (myocardial flow ratio < 2.0) in the RCA region and examined hemodynamics, cardiac function, and coronary aneurysm diameter. These variables were also compared in patients with/without RCA segmental stenosis (SS).

RESULTS

There were five cases of ischemia in the RCA region. RCA myocardial blood flow (MBF) at rest was higher in patients with ischemia than in those without ischemia, but the difference was not significant (1.27 ± 0.21 vs. 0.82 ± 0.16 mL/min/g, p = 0.2053). Nine patients presented with RCA SS, and age at onset of Kawasaki disease tended to be lower in those with SS. The maximum aneurysm diameter of RCA was significantly smaller in patients with SS (10.0 ± 2.8 vs. 14.7 ± 1.6, p = 0.0239). No significant differences in other variables were observed between patients with/without ischemia and SS.

CONCLUSIONS

At rest, MBF in the RCA region was relatively well preserved, even in patients with RCA occlusion, and there was no progressive deterioration in cardiac function. Adenosine stress showed microcirculatory disturbances in only half of the patients, indicating that it is reversible in children with Kawasaki disease.

Efficacy of Angiotensin-Converting Enzyme Inhibitors in Coronary Microvascular Dysfunction: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Coronary microvascular dysfunction (CMD) is becoming increasingly recognized as an important contributor to the development of ischemic heart diseases. Without obstructive coronary artery disease, the physiological function of the coronary microcirculation can be altered by structural, functional, and molecular factors, leading to myocardial ischemia. CMD can significantly impact the quality of life and prognosis and imposes a huge financial burden on healthcare systems and people. This meta-analysis aims to investigate the efficacy of angiotensin-converting enzyme inhibitors (ACEIs) for treating CMD. A systematic literature review identified randomized controlled trials (RCTs) comparing ACEIs with placebo in CMD patients. Review Manager, 5.3 for Windows, was utilized. Using the Mantel-Haenszel (M-H) method, improvement in coronary flow reserve (CFR) and systolic blood pressure events was pooled as mean difference (MD) in a meta-analysis model with a fixed effect model, whereas the number of chest pain episodes was pooled as MD with a random effect model. Five randomized controlled trials involving 209 patients were included in the analysis. The analysis demonstrated a statistically significant improvement in CFR in the ACEIs group compared to the placebo group (MD -0.3, 95% CI -0.61 to 0.01, P = 0.05). However, there was no significant difference in the number of chest pain episodes between the ACEIs and placebo groups (MD 1.79, 95% CI -3.99 to 7.58, P = 0.54). Similarly, no significant difference in blood pressure change was observed between the two groups (MD 4.02, 95% CI -3.25 to 11.28, P = 0.28). In conclusion, the appropriate treatment for CMD is a source of contention because adequate data is lacking. Our findings suggest that ACEIs may have a positive effect on improving CFR in patients with microvascular angina. However, ACEIs did not demonstrate a significant impact on the number of chest pain episodes or systolic blood pressure in this patient population. Further research, including RCTs with larger sample sizes and longer follow-up durations, is warranted to provide more conclusive evidence on the role of ACEIs in CMD management.

Targeted Therapies for Microvascular Disease

Coronary microvascular dysfunction (CMD) is a common cause of ischemia but no obstructive coronary artery disease that results in an inability of the coronary microvasculature to meet myocardial oxygen demand. CMD is challenging to diagnose and manage due to a lack of mechanistic research and targeted therapy. Recent evidence suggests we can improved patient outcomes by stratifying antianginal therapies according to the diagnosis revealed by invasive assessment of the coronary microcirculation. This review article appraises the evidence for management of CMD, which includes treatment of cardiovascular risk, antianginal therapy and therapy for atherosclerosis.

Prognostic Role of Myocardial Flow Reserve in Heart Failure With Preserved Ejection Fraction

Aim      To study the role of myocardial blood flow (MBF) and myocardial flow reserve (MFR) in patients with heart failure with preserved ejection fraction (HFpEF) in stratifying the risk of HFpEF progression during 12 months of follow-up.Material and methods  The study included 58 patients with non-obstructive coronary artery disease and HFpEF. Concentrations of N-terminal pro-brain natriuretic peptide (NT-proBNP) were measured using an enzyme-linked immunosorbent assay. MFR and MBF were determined by dynamic single-photon emission computed tomography of the myocardium.Results At 12 months, the patients were divided into two groups: group 1 (n=11) included patients with an unfavorable course of HFpEF, group 2 (n=47) included patients with a favorable course. A multivariate analysis showed that NT-proBNP concentrations (odds ratio (OR), 3.23; 95% confidence interval (CI), 1.76-6.78; p=0.008) and MFR (OR, 8.09; 95% CI, 5.12-19.98; p<0.001) were independent predictors of adverse outcomes. According to ROC analysis, values of MFR ≤1.62 (area under the curve (AUC)=0.827; p<0.001) and NT-proBNP ≥760.5 pg/ml (AUC=0.708; p=0.040) can be considered as markers for HFpEF progression. Furthermore, the combined measurement of NT-proBNP concentration and MFR had a higher prognostic significance (AUC, 0.954; p<0.001).Conclusion      Values of NT-proBNP and MFR can be used as noninvasive markers for an unfavorable course of HFpEF, and their combined measurement increases the prognostic significance.

MINOCA: Diagnostic work-up, risk stratification and tailored therapies

Myocardial infarction with no obstructive coronary artery disease (MINOCA) diagnostic work-up, risk stratification and tailored therapies are emerging as the recognition of this type of MI is increasingly recognized. Diagnostic workup using advanced imaging can include coronary angiography/intravascular ultrasound (IVUS)/optical coherent tomography (OCT), echo and cardiac magnetic resonance imaging (MRI). Risk stratification portends an intermediate risk compared to multivessel obstructive coronary artery disease (CAD). While event rates are high enough to warrant concern, they are relatively low enough to require trials with large sample sizes and hard outcomes. Tailored therapies include common sense therapeutic lifestyle change (TLC) and optimal medical therapy (OMT) due to the high prevalence of non-obstructive CAD, however therapeutic clinical trials are needed. Currently one large outcome trial in ischemia with no obstructive coronary artery disease (INOCA) is ongoing.

Chinese expert consensus on the diagnosis and treatment of coronary microvascular diseases (2023 Edition)

Since the four working groups of the Chinese Society of Cardiology issued first expert consensus on coronary microvascular diseases (CMVD) in 2017, international consensus documents on CMVD have increased rapidly. Although some of these documents made preliminary recommendations for the diagnosis and treatment of CMVD, they did not provide classification of recommendations and levels of evidence. In order to summarize recent progress in the field of CMVD, standardize the methods and procedures of diagnosis and treatment, and identify the scientific questions for future research, the four working groups of the Chinese Society of Cardiology updated the 2017 version of the Chinese expert consensus on CMVD and adopted a series of measures to ensure the quality of this document. The current consensus has raised a new classification of CMVD, summarized new epidemiological findings for different types of CMVD, analyzed key pathological and molecular mechanisms, evaluated classical and novel diagnostic technologies, recommended diagnostic pathways and criteria, and therapeutic strategies and medications, for patients with CMVD. In view of the current progress and knowledge gaps of CMVD, future directions were proposed. It is hoped that this expert consensus will further expedite the research progress of CMVD in both basic and clinical scenarios.

Diseases of the Coronary Microcirculation: Diagnosis and Treatment

BACKGROUND

Coronary microvascular dysfunction (CMD) comprises a variety of pathogenic mechanisms that impair the microcirculation of the heart. Clinical studies have shown that 30-50% of patients suffering from myocardial ischemia without significant coronary artery stenosis have CMD. The disease is associated with ele - vated mortality and poor quality of life. Whenever a patient presents with symptoms of angina pectoris and no underlying disease is detected by the usual methods, CMD should be considered a possible cause.

METHODS

This review is based on publications retrieved by a selective search in PubMed and on current international guidelines and recommendations of specialty societies.

RESULTS

The diagnosis of CMD is based on objective evidence of a microvascular origin of symptoms. The guidelines contain a class IIa recommendation for invasive coronary flow reserve and microvascular resistance measurements. Noninvasive tests such as positron emission tomography and cardiac magnetic resonance imaging are less accurate and are given a class IIb recommendation. No highquality therapeutic trials are available to date, and the treatment of CMD is thus based on that of chronic coronary syndrome. Lifestyle modification is performed to reduce risk factors. Patients with an abnormal coronary flow reserve or elevated microvascular resistance can be treated with an ACE inhibitor or angiotensin receptor blocker. Beta-blockers and calcium channel antagonists can relieve angina pectoris. Statins lower the LDL level and have positive pleiotropic effects. First-line treatment can be supplemented with further medications.

CONCLUSION

Approximately 25% of patients with CMD have symptoms that do not respond to intensive treatment with the currently available modalities. New treatments, including interventional therapies, are being studied. Their long-term benefit remains to be assessed and compared to that of the existing methods.

Atherosclerosis in Systemic Lupus Erythematosus

PURPOSE OF THE REVIEW

Systemic lupus erythematosus (SLE) patients are at increased risk of cardiovascular disease (CVD) compared to the general population, despite most patients being young females, who are not classically considered to be at high risk for cardiovascular disease using traditional risk assessment tools. The purpose of this review is to discuss the pathophysiology of atherosclerosis in SLE and raise awareness of the relationship between SLE and CVD.

RECENT FINDINGS

The increased risk of CVD in SLE patients is multifactorial, due to proatherogenic lipid profiles, immune dysregulation and inflammation, side effects of lupus treatment, and microvascular dysfunction. Conventional CV risk models often underperform in the identification of SLE patients at high risk of atherosclerosis. The use of non-invasive imaging serves as a strategy to identify patients with evidence of subclinical CVD and in the evaluation of symptomatic patients. Identification of subclinical atherosclerosis allows for aggressive management of CV risk factors. SLE patients experience an increased risk of atherosclerotic CVD, which is not solely explained by traditional CV risk factors. It is imperative that clinicians are aware of this association to implement prompt detection and treatment of atherosclerotic CVD in SLE patients.

Health-related quality-of-life up to one year after myocardial infarction with non-obstructive coronary arteries

AIMS

Patients with Myocardial Infarction with Non-Obstructive Coronary Arteries (MINOCA) are a heterogenous group and previous studies indicate a decreased Health-related quality-of-life (HRQoL) compared with patients with myocardial infarction with obstructive coronary artery disease and healthy individuals. However, longitudinal data are scarce. Therefore, the aim was to explore HRQoL among patients with MINOCA during a one-year period after the acute event in comparison with a group of healthy individuals and to describe HRQoL in patients with Takotsubo Syndrome (TTS).

METHODS AND RESULTS

Patients with MINOCA were recruited from five hospitals in the Stockholm region (SMINC-2 study, clinical trials: NCT2318498). Patients responded to the HRQoL questionnaire RAND-36 between days 2-4, after 6 and 12 months respectively. A sample of population-based individuals was used as a comparison group. A total of 142 MINOCA patients, (70% women) mean age of 56 years, responded. A population-based sample of 317 volunteers (66% women) mean age of 57 years. Patients with MINOCA scored lower than the comparison group in the domains role functioning physical, social functioning, and role functioning emotional (P = 0.01-0.02) at 12 months. In these domains of HRQoL there was no improvement in MINOCA patients during 12 months follow-up. In the domains of energy/fatigue vitality and emotional well-being the scores improved and were similar to the comparison group at 12 months. Patients with TTS scored generally lower on RAND-36 than MINOCA patients without TTS.

CONCLUSION

Physical, social, and emotional functioning did not improve during the first year after MINOCA, indicating a need for increased follow-up including psychological support.

The Mechanism of Effort Intolerance in Patients with Peripheral Arterial Disease: A Combined Stress Echocardiography and Cardiopulmonary Exercise Test

AIM

We used a combined stress echocardiography and cardiopulmonary exercise test (CPET) to explore effort intolerance in peripheral arterial disease (PAD) patients.

METHODS

Twenty-three patients who had both PAD and coronary artery disease (CAD) were compared with twenty-four sex- and age-matched CAD patients and fifteen normal controls using a symptom-limited ramp bicycle CPET on a tilting dedicated ergometer. Echocardiographic images were obtained concurrently with gas exchange measurements along predefined stages of exercise. Oxygen extraction was calculated using the Fick equation at each activity level.

RESULTS

Along the stages of exercise (unloaded; anaerobic threshold; peak), in PAD + CAD patients compared with CAD or controls, diastolic function worsened (p = 0.051 and p = 0.013, respectively), and oxygen consumption (p < 0.001 and p < 0.001, respectively) and oxygen pulse (p = 0.0024 and p = 0.0027, respectively) were reduced. Notably, oxygen pulse was blunted due to an insufficient increase in both stroke volume (p = 0.025 and p = 0.028, respectively) and peripheral oxygen extraction (p = 0.031 and p = 0.038, respectively). Chronotropic incompetence was more prevalent in PAD patients and persisted after correction for beta-blocker use (62% vs. 42% and 11%, respectively).

CONCLUSIONS

In PAD patients, exercise limitation is associated with diastolic dysfunction, chronotropic incompetence and peripheral factors.

Coronary Microvascular Dysfunction: What Clinicians and Investigators Should Know

PURPOSE OF REVIEW

Abnormal structure and function of the coronary microvasculature have been implicated in the pathophysiology of multiple cardiovascular disease processes. This article reviews recent research progress related to coronary microvascular dysfunction (CMD) and salient clinical takeaways.

RECENT FINDINGS

CMD is prevalent in patients with signs and symptoms of ischemia and no obstructive epicardial coronary artery disease (INOCA), particularly in women. CMD is associated with adverse outcomes, including most frequently the development of heart failure with preserved ejection fraction. It is also associated with adverse outcomes in patient populations including hypertrophic cardiomyopathy, dilated cardiomyopathy, and acute coronary syndromes. In patients with INOCA, stratified medical therapy guided by invasive coronary function testing to define the subtype of CMD leads to improved symptoms. There are invasive and non-invasive methodologies to diagnose CMD that provide prognostic information and mechanistic information to direct treatment. Available treatments improve symptoms and myocardial blood flow; ongoing investigations aim to develop therapy to improve adverse outcomes related to CMD.

Case report: Repeat coronary function testing in women with ischemia and no obstructive coronary artery disease

Women with signs and symptoms of ischemia and no obstructive coronary artery disease (INOCA) often have coronary microvascular dysfunction (CMD). It can be diagnosed by coronary function testing (CFT), which is an invasive coronary angiogram procedure. Frequently, these women have persistent angina despite medical therapy, but it is not clear whether it is due to worsening or persistent CMD or inadequate therapy. In this brief report, we describe findings of repeat CFT in a case series of 12 women undergoing repeat CFT for the assessment of persistent angina in order to better understand the evolving pathology.

Coronary microvascular dysfunction and cardiovascular disease: Pathogenesis, associations and treatment strategies

Coronary microvascular dysfunction (CMD) is a high-risk factor for a variety of cardiovascular events. Due to its complex aetiology and concealability, knowledge of the pathophysiological mechanism of CMD is still limited at present, which greatly restricts its clinical diagnosis and treatment. Studies have shown that CMD is closely related to a variety of cardiovascular diseases, can aggravate the occurrence and development of cardiovascular diseases, and is closely related to a poor prognosis in patients with cardiovascular diseases. Improving coronary microvascular remodelling and increasing myocardial perfusion might be promising strategies for the treatment of cardiovascular diseases. In this paper, the pathogenesis and functional assessment of CMD are reviewed first, along with the relationship of CMD with cardiovascular diseases. Then, the latest strategies for the treatment of CMD and cardiovascular diseases are summarized. Finally, urgent scientific problems in CMD and cardiovascular diseases are highlighted and future research directions are proposed to provide prospective insights for the prevention and treatment of CMD and cardiovascular diseases in the future.

The impact of diabetes on the relationship of coronary artery disease and outcome: a study using multimodality imaging

BACKGROUND

Patients with prediabetes or diabetes are at increased risk of developing cardiovascular disease and adverse outcomes. First-line coronary computed tomography angiography (CTA) followed by selective use of positron emission tomography (PET) myocardial perfusion imaging is a feasible strategy to diagnose and risk-stratify patients with suspected coronary artery disease (CAD). The aim of the present study was to study whether diabetes changes the relationship of CAD and long-term outcome.

METHODS

We retrospectively identified consecutive symptomatic patients who underwent coronary CTA for suspected CAD. In patients with suspected obstructive CAD on CTA, myocardial ischemia was evaluated by ¹⁵O-water PET myocardial perfusion imaging. The relationship of the phenotype of CAD and long-term outcome in patients with no diabetes, prediabetes, or type 2 diabetes was investigated. A composite endpoint included all-cause mortality, myocardial infarction (MI), and unstable angina pectoris (UAP).

RESULTS

A total of 1743 patients were included: 1214 (70%) non-diabetic, 259 (15%) prediabetic, and 270 (16%) type 2 diabetic patients. During 6.43 years of median follow-up, 164 adverse events occurred (106 deaths, 41 MIs, 17 UAPs). The prevalence of normal coronary arteries on CTA was highest in the non-diabetic patients (39%). The prevalence of hemodynamically significant CAD (abnormal perfusion) increased from 14% in non-diabetic patients to 20% in prediabetic and 27% in diabetic patients. The event rate was lowest in patients with normal coronary arteries and highest in patients with concomitant type 2 diabetes and hemodynamically significant CAD (annual event rate 0.2% vs. 4.7%). However, neither prediabetes nor diabetes were independent predictors of the composite adverse outcome after adjustment for the clinical risk factors and imaging findings.

CONCLUSIONS

Coronary CTA followed by selective downstream use of PET myocardial perfusion imaging predicts long-term outcome similarly in non-diabetic and diabetic patients.

Comparative Evaluation of Captopril, Spironolactone, and Carvedilol Effect on Endothelial Function in Breast Cancer Women Undergoing Chemotherapy

Background

Breast cancer is the most prevalent malignancy in females which needs chemotherapy treatment. Studies demonstrated that anti-cancer agents used for chemotherapy in cancer patient causes endothelium dysfunction. Several researches showed the efficacy of angiotensin-converting enzyme inhibitors, Carvedilol and Spironolactone on improving endothelial function. This study aimed to evaluate the effect of the combination of Spironolactone, Carvedilol, and Captopril on endothelial function in breast cancer patients.

Materials and Methods

This study is a prospective Randomized Clinical Trial in breast cancer patients who underwent chemotherapy. Patients were divided into two groups who received the combination of Captopril, Spironolactone, and Carvedilol or standard regimen for 3 months during chemotherapy. Before and after intervention, ejection fraction (EF), E/A ratio and e' and flow-mediated dilation (FMD) properties were calculated and then compared.

Results

Fifty-eight patients with a mean age of 47.57 ± 9.46 years were evaluated. The mean FMD after the intervention is statistically different in case and controls (<0.001). E/A ratio and e' are not statistically different between groups after intervention. The mean EF was not statistically different between the two groups after intervention.

Conclusion

Prescribing combination of Carvedilol, Spironolactone, and Captopril in breast cancer patients undergoing chemotherapy can improve endothelial function and may have beneficial effects on diastolic function.