Pathophysiology of coronary microvascular dysfunction

Coronary microvascular dysfunction: pathophysiology, diagnosis, and therapeutic strategies across cardiovascular diseases

Ischemic heart disease (IHD) is a leading cause of morbidity and mortality worldwide, presenting with acute and chronic coronary syndromes. Although coronary atherosclerosis is a major cause of IHD, many patients with angina or myocardial ischemia do not have obstructive coronary heart disease and impairment of the coronary microcirculation has been increasingly implicated as a relevant cause of IHD. Therefore, coronary microvascular dysfunction (CMD) refers to a term covering a wide spectrum of structural and functional alterations which affect the coronary microcirculation leading to myocardial ischemia and angina. The advent of non-invasive and invasive functional tests has exponentially broadened the ability to recognize CMD and delineate related clinical and biochemical features. Despite major advances in diagnosing and stratifying this condition, therapeutic strategies remain limited and poorly defined. In this review, we will provide an overview of the pathophysiology and the diagnostic evaluation of CMD across the spectrum of cardiovascular diseases. Furthermore, we will discuss the novel therapeutic strategies available for these patients in the perspective of a personalized medicine approach.

Oxygen-ozone therapy for myocardial ischemic stroke and cardiovascular disorders

Cardiovascular diseases (CVDs) represent a major concern for human health worldwide. Emergencies in this field include wide repertories of studies dealing primarily with CVD prevention. In addition to dietary habits and lifestyles, medical knowledge is fully needed to improve public educational programs toward cardiovascular risk factors and to enrich the endowment of pharmaceutical options and therapies to address CVDs, particularly for ischemic damage due to an impairment in the endothelial-myocardial relationship. Because ozone is a stimulator of the endothelial nitric oxide synthase/nitric oxide pathway, ozone therapy has been widely demonstrated to have the ability to counteract endothelial-cardiac disorders, providing a novel straightforward opportunity to reduce the impact of CVDs, including atrial fibrillation. In this review, we attempt to establish a state-of-the-art method for the use of ozone in CVD, suggesting that future remarks be addressed to provide fundamental insights into this issue. The purpose of this study was to highlight the role of ozone in the adjunctive medical treatment of cardiovascular pathologies such as acute myocardial infarction due to ischemic disorders.

Beyond the Obstructive Paradigm: Unveiling the Complex Landscape of Nonobstructive Coronary Artery Disease

Traditionally focused on obstructive atherosclerosis, contemporary research indicates that up to 70% of patients undergoing coronary angiography for angina and ischemic symptoms do not exhibit significant stenoses. Nonobstructive coronary artery disease (CAD) has emerged as a prevalent phenotype among these patients. This review emphasizes the emerging understanding that nonobstructive coronary artery disease, encompassing conditions such as ANOCA (Angina with No Obstructive Coronary Artery Disease), INOCA (Ischemia with No Obstructive Coronary Artery Disease), and MINOCA (Myocardial Infarction with No Obstructive Coronary Arteries), represents the most prevalent phenotype in cardiac patients. It delves into the complex pathophysiology underlying these conditions, focusing on microvascular dysfunction and coronary vasoreactivity, which contribute to myocardial ischemia despite the absence of significant coronary obstructions. Additionally, the review critically examines the limitations of current treatments which primarily target obstructive lesions and underscores the necessity for tailored therapies that address the specific microvascular and immunoinflammatory pathways involved in nonobstructive CAD. The main focus of this review is to advocate for a shift in diagnostic and therapeutic strategies to better identify and manage this widely prevalent yet under-recognized subset of CAD.

Microvascular Dysfunction across the Spectrum of Heart Failure Pathology: Pathophysiology, Clinical Features and Therapeutic Implications

Coronary microvascular dysfunction (CMD) plays a crucial role across the spectrum of heart failure (HF) pathology, contributing to disease development, progression, and outcomes. The pathophysiological mechanisms linking CMD to HF are complex and still not completely understood and include chronic inflammation, oxidative stress, and neurohormonal activation. Despite the diagnostic and prognostic relevance in patients with HF, there is no specific therapeutic strategy targeting CMD to date. Moreover, the diagnosis of this clinical condition is challenging. In this review article, we aim to discuss the different clinical pathogenetic mechanisms linking CMD to HF across the different spectra of these diseases, their prognostic relevance, and the possible therapeutic targets along with the remaining knowledge gaps in the field.

Coronary microvascular dysfunction, arrythmias, and sudden cardiac death: A literature review

The coronary vascular system has a unique structure and function that is adaptive to myocardial demand. It is composed of a continuous network of vessels receding in size from epicardial arteries to the microvascular circulation. Failure to meet myocardial demand results in ischemia, angina, and adverse myocardial outcomes. It is evident that 50 % of patients with angina have a non-obstructive coronary disease and 66 % of these patients have coronary microvascular dysfunction (CMD). The impact of CMD on the atria and ventricles is exhibited through its association with atrial fibrillation and distortion of ventricular repolarization. Ultimately, this influence increases the risk of mortality, morbidity, and sudden cardiac arrest. CMD serves as an independent risk for atrial fibrillation, increases ventricular electrical inhomogeneity, and contributes to the progression of cardiac disease. The underlying pathogenesis may be attributed to oxidative stress evident through reactive oxygen species, impaired vasoactive function, and structural disorders such as fibrotic changes. Myocardial ischemia, brought about by a demand-supply mismatch in CMD, may create a milieu for ventricular arrythmia and sudden cardiac arrest through distortion of ventricular repolarization parameters such as QT dispersion and corrected QT dispersion.