coronary microvascular dysfunction

During an acute coronary syndrome, atherosclerotic plaque rupture triggers platelet activation and thrombus formation, which may completely occlude a coronary artery leading to ST-elevation myocardial infarction (STEMI). Although emergency percutaneous coronary intervention (PCI) is effective in re-opening the main coronary arteries, the downstream microvasculature can become obstructed by embolised plaque material and thrombus. Dual antiplatelet therapy is recommended by guidelines and used routinely for the management of STEMI to reduce the risk of recurrent atherothrombotic events...

The occurrence and development of myocardial dysfunction are associated with damage in the cardiac microvascular endothelial cells (CMECs), which can regulate nutrient exchange and oxy-gen-carbon cycling to protect cardiomyocytes. Interventions targeting microRNAs (miRNAs) can effectively mitigate CMEC injury and thus improve cardiovascular diseases. MiRNAs are a class of noncoding single-strand RNA molecules typically 21-23 nucleotides in length that are encoded by endogenous genes. They are critical regulators of organism development, cell differentiation, metabolism, and apoptosis...

Coronary vasomotor disorders (CVD) are characterized by transient hypercontraction of coronary vascular smooth muscle cells, leading to hypercontraction of epicardial and/or microvascular coronary circulation. CVDs play a relevant role in the pathogenesis of ischemia, angina and myocardial infarction with non-obstructive coronary arteries. Invasive provocative testing with intracoronary Acetylcholine (ACh) administration is the gold standard tool for addressing CVD, providing relevant therapeutic and prognostic implications...

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BACKGROUND: Microvascular resistance reserve (MRR) is a novel index reflecting coronary microcirculatory function, irrespective of epicardial coronary artery stenosis. There is limited evidence regarding whether MRR can be an independent prognostic tool in patients with stable ischemic heart disease (IHD). OBJECTIVES: The aim of this study was to evaluate clinical outcomes according to MRR in patients with stable IHD accompanied with or without significant epicardial coronary artery stenosis...

Immune checkpoint inhibitors (ICIs) exhibit remarkable antitumor activity and immune-related cardiotoxicity of unknown pathomechanism. The aim of the study was to investigate the ICI class-dependent cardiotoxicity in vitro and pembrolizumab's (Pem's) cardiotoxicity in vivo, seeking for translational prevention means. Cytotoxicity was investigated in primary cardiomyocytes and splenocytes, incubated with ipilimumab, Pem and avelumab. Pem's cross-reactivity was assessed by circular dichroism (CD) on biotechnologically produced human and murine PD-1 and in silico...

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...

BACKGROUND: Clinical management of patients with angina and no obstructive coronary artery disease (ANOCA) is still challenging. This scenario affects up to 50% of patients undergoing diagnostic coronary angiography due to suspected coronary artery disease. Many patients report a long and debilitating history before adequate diagnostics and management are initiated. OBJECTIVES: This article describes the current recommendations for diagnostic assessments and treatment in patients with ANOCA...

Over half of all patients with angina have no angiographically demonstratable obstructive coronary disease, with a significant proportion of these patients having undiagnosed microvascular dysfunction and/or vasospastic angina. In chronic coronary syndrome, ischemia with non-obstructive coronary artery disease (INOCA) often remains undiagnosed, or uninvestigated. INOCAmay occur due to vasospastic angina and microvascular dysfunction and require invasive assessment in the coronary catheterization lab. To evaluate INOCA coronary flow reserve (CFR) and the index of microcirculatory resistance (IMR) are used to assess microvascular dysfunction before acetylcholine provocation testing for coronary spasm...

Myocardial infarction without obstructive coronary artery disease (MINOCA) is defined as myocardial infarction with mild or no obstructive coronary artery disease (CAD) on angiogram. MINOCA has a number of heterogeneous causes, including coronary disruption, coronary vasospasm, coronary embolism, spontaneous coronary artery dissection (SCAD), and coronary microvascular dysfunction (CMD). Even though MINOCA might have a better prognosis than MI with obstructive CAD, it is not benign. A stepwise diagnostic approach is crucial to identifying the underlying cause of MINOCA or conditions mimicking it...

Cardiac amyloidosis (CA) is an infiltrative disease caused by amyloid fibril deposition in the myocardium; the 2 forms that most frequently involve the heart are amyloid light chain (AL) and amyloid transthyretin (ATTR) amyloidosis. Cardiac troponin (cTn) is the biomarker of choice for the detection of myocardial injury and is frequently found to be elevated in patients with CA, particularly with high-sensitivity assays. Multiple mechanisms of myocardial injury in CA have been proposed, including cytotoxic effect of amyloid precursors, interstitial amyloid fibril infiltration, coronary microvascular dysfunction, amyloid- and non-amyloid-related coronary artery disease, diastolic dysfunction, and heart failure...

BACKGROUND: Preeclampsia is a pregnancy-specific hypertensive disorder associated with an imbalance in circulating pro- and anti-angiogenic proteins. Preclinical evidence implicates microvascular dysfunction as a potential mediator of preeclampsia-associated cardiovascular risk. METHODS: Women with singleton pregnancies complicated by severe antepartum-onset preeclampsia and a comparator group with normotensive deliveries underwent cardiac positron emission tomography (PET) within 4 weeks of delivery...

BACKGROUND: The assessment of coronary microvascular dysfunction (CMD) using invasive methods is a field of growing interest, however the preferred method remains debated. Bolus and continuous thermodilution are commonly used methods, but weak agreement has been observed in patients with angina with non-obstructive coronary arteries (ANOCA). This study examined their agreement in revascularized acute coronary syndromes (ACS) and chronic coronary syndromes (CCS) patients. OBJECTIVE: To compare bolus thermodilution and continuous thermodilution indices of CMD in revascularized ACS and CCS patients and assess their diagnostic agreement at pre-defined cut-off points...

Ischemic heart disease (IHD) is the leading cause of morbidity and mortality in both genders; however, young women fare the worst, likely reflecting the more complex spectrum of IHD in women when compared to men. Substantial sex-based differences exist in the underlying risk factors, risk enhancers, presentation, diagnosis, and pathophysiology of IHD that are mainly attributed to the influence of female sex hormones. This article reviews the spectrum of IHD including obstructive epicardial coronary artery disease (CAD), myocardial infarction with no obstructive coronary artery disease, ischemia with no obstructive coronary artery disease, spontaneous coronary artery dissection, coronary microvascular dysfunction, vasospastic angina, and coronary thrombosis/embolism that occur in women throughout various stages of their life cycle...

BACKGROUND AND OBJECTIVES: Chest pain is a relatively long-term symptom that commonly occurs in patients who have contracted COVID-19. The reasons for these symptoms remain unclear, with coronary microvascular dysfunction (CMD) emerging as a potential factor. This study aimed to assess the presence of CMD in these patients by measuring the angio-derived index of microcirculatory resistance (AMR). METHODS: In this cross-sectional case-control study, patients who had chest pain and a history of COVID-19 infection within the preceding 30 to 60 days were included...

Obesity condition causes morphological and functional alterations involving the cardiovascular system. These can represent the substrates for different cardiovascular diseases, such as atrial fibrillation, coronary artery disease, sudden cardiac death, and heart failure (HF) with both preserved ejection fraction (EF) and reduced EF. Different pathogenetic mechanisms may help to explain the association between obesity and HF including left ventricular remodelling and epicardial fat accumulation, endothelial dysfunction, and coronary microvascular dysfunction...

BACKGROUND: Myocardial infarction with nonobstructive coronary artery disease (MINOCA) is defined as acute myocardial infarction (AMI) with angiographically nonobstructive coronary artery disease. MINOCA represents 6% of all AMI cases and is associated with increased mortality and morbidity. However, the wide array of pathophysiological factors and causes associated with MINOCA presents a diagnostic conundrum. Therefore, we conducted a contemporary systematic review of the pathophysiology of MINOCA...

BACKGROUND: Coronary microvascular disease (CMD) is common in patients with and without obstructive coronary artery disease, and is associated with adverse clinical outcomes. Respiratory-related variables are associated with pulmonary and systemic microvascular dysfunction, while evidence regarding their relationship with CMD is limited. We aim to evaluate respiratory-related variables as risk factors of CMD. METHODS: This is an observational, single-center study enrolling consecutive patients undergoing invasive evaluation of coronary microvascular function in the catheterization laboratory...

UNLABELLED: The patient, a 68-year-old man, presented to our emergency room with chest pain, prompting an emergency cardiac catheterization due to elevated cardiac troponin-I levels. While no obvious coronary artery stenosis was found, there was evidence of apical ballooning wall motion in the left ventricle, leading to a diagnosis of takotsubo syndrome. Three months later, he occasionally experienced chest pain at rest, prompting us to conduct another cardiac catheterization. Left ventriculography showed normal contraction...

AIMS: Long-standing hypertension may cause an impairment in microvascular coronary circulation, which is involved in many different cardiac conditions. Renal sympathetic denervation (RDN) has been successfully proven as a valuable therapeutic choice for patients with resistant hypertension; moreover, the procedure looks promising in other settings, such as heart failure and atrial fibrillation, given its ability to downregulate the sympathetic nervous system, which is a recognized driver in these conditions as well as in microvascular dysfunction progression...