Microcirculation and Heart Failure

Abstract

The idea of coronary microcirculation playing a role in the pathophysiology of heart failure dates from decades ago, with authors hypothesizing that structural and functional alterations in the coronary microcirculation could potentially contribute to heart failure. It is known that in a wide range of primary cardiomyopathies, from dilated to hypertrophic, there are pathological alterations in myocardial vasculature structure and function, playing a role in the clinical course of the disease. Needless to say, many patients with normal epicardial coronary arteries can suffer from coronary microvascular dysfunction, that could lead to a wide variety of clinical problems - from impaired functional capacity to stable and unstable angina, Takotsubo syndrome, myocardial infarction with normal coronary arteries and can also end up with either acute or chronic heart failure. Furthermore, nowadays, it has been recognized that pathophysiology of the heart failure with preserved ejection fraction (HFpEF) is mainly due to the myocardial microcirculatory impairment. In heart failure with reduced ejection fraction (HFrEF) neurohumoral mechanisms affecting the peripheral vasculature have been identified as important factors in the development and progression of heart failure, leading to unfavourable remodelling, and thus some of them being important treatment targets. Among many new clinical scenarios where both myocardial and peripheral microcirculation play an important role, raising field of implantable continuous flow assist devices opens many questions and implies better understanding of their effects of microcirculation, as they usually lead to the improvement of end organ dysfunction caused by previous heart failure, which is probably through the positive effects of peripheral microcirculation.

Enhanced Antioxidative Defense by Vitamins C and E Consumption Prevents 7-Day High-Salt Diet-Induced Microvascular Endothelial Function Impairment in Young Healthy Individuals

“…An increasing body of evidence indicates the importance of microvascular impairment in the development of CV diseases [32][33][34]. In order to separate well established effect of elevated BP on vascular (endothelial) function from the effect of salt loading, studies were shifted from investigating hypertensive patients to the population of healthy individuals.…”

Ischemic Heart Disease and Heart Failure: Role of Coronary Ion Channels

“…Over the past few years, some authors have hypothesized the central role for CMD in the pathophysiology of HF and in myocardial remodeling [29][30][31][32].…”

“…Moreover, other authors have suggested a link between CMD, through endothelial dysfunction, and severity of symptoms in HF patients [32,33]. According to ALLAHAT trial and MEDIA (The Metabolic Road to Diastolic Heart Failure) European registry for HF, a high body mass index is often seen in these patients and cardiovascular risk factors, such as arterial hypertension, diabetes mellitus and dyslipidemia may lead to HF through microvascular dysfunction.…”

“…Endothelial dysfunction is associated with a reduced bioavailability of NO and reduced activity of K ATP . Moreover, CMD stimulates cardiomyocytes hypertrophy, fibrosis and microvascular rarefaction, which are the main histological alterations seen in HF [32,[34][35][36].…”

High-Density Lipoprotein-Targeted Therapies for Heart Failure

“…Under baseline conditions, oxygen extraction from the arterial blood in the myocardium is close to 70%, and consequently, a rise in myocardial oxygen demand can only be met by a proportionate increase in coronary blood flow. Structural and functional alterations in the coronary microcirculation may contribute to and/or aggravate heart failure [34,35]. Beneficial effects of HDLs on the coronary microcirculation may therefore be a mediator on the causal pathway between HDL-targeted therapies and clinically relevant endpoints.…”