Ischemic heart disease still represents a large burden on individuals and health care resources worldwide. By conventions, it is equated with atherosclerotic plaque due to flow-limiting obstruction in large–medium sized coronary arteries. However, clinical, angiographic and autoptic findings suggest a multifaceted pathophysiology for ischemic heart disease and just some cases are caused by severe or complicated atherosclerotic plaques. Currently there is no well-defined assessment of ischemic heart disease pathophysiology that satisfies all the observations and sometimes the underlying mechanism to everyday ischemic heart disease ward cases is misleading. In order to better examine this complicated disease and to provide future perspectives, it is important to know and analyze the pathophysiological mechanisms that underline it, because ischemic heart disease is not always determined by atherosclerotic plaque complication. Therefore, in order to have a more complete comprehension of ischemic heart disease we propose an overview of the available pathophysiological paradigms, from plaque activation to microvascular dysfunction.

Heart failure is a complex syndrome responsible for high rates of death and hospitalization. Ischemic heart disease is one of the most frequent causes of heart failure and it is normally attributed to coronary artery disease, defined by the presence of one or more obstructive plaques, which determine a reduced coronary blood flow, causing myocardial ischemia and consequent heart failure. However, coronary obstruction is only an element of a complex pathophysiological process that leads to myocardial ischemia. In the literature, attention paid to the role of microcirculation, in the pathophysiology of ischemic heart disease and heart failure, is growing. Coronary microvascular dysfunction determines an inability of coronary circulation to satisfy myocardial metabolic demands, due to the imbalance of coronary blood flow regulatory mechanisms, including ion channels, leading to the development of hypoxia, fibrosis and tissue death, which may determine a loss of myocardial function, even beyond the presence of atherosclerotic epicardial plaques. For this reason, ion channels may represent the link among coronary microvascular dysfunction, ischemic heart disease and consequent heart failure.

Advanced heart failure (AdHF) represents a challenging aspect of heart failure patients. Because of worsening clinical symptoms, high rates of re-hospitalization and mortality, AdHF represents an unstable condition where standard treatments are inadequate and additional interventions must be applied. A heart transplant is considered the optimal therapy for AdHF, but the great problem linked to the scarcity of organs and long waiting lists have led to the use of mechanical circulatory support with ventricular-assist device (VAD) as a destination therapy. VAD placement improves the prognosis, functional status, and quality of life of AdHF patients, with high rates of survival at 1 year, similar to transplant. However, the key element is to select the right patient at the right moment. The complete assessment must include a careful clinical evaluation, but also take into account psychosocial factors that are of crucial importance in the out-of-hospital management. It is important to distinguish between AdHF and end-stage HF, for which advanced therapy interventions would be unreasonable due to severe and irreversible organ damage and, instead, palliative care should be preferred to improve quality of life and relief of suffering. The correct selection of patients represents a great issue to solve, both ethically and economically.

Background: IHD is determined by an inadequate coronary blood supply to the myocardium, and endothelial dysfunction may represent one of the main pathophysiological mechanisms involved. Genetic predisposition to endothelial dysfunction has been associated with IHD and its clinical manifestation. However, studies are often confounding and inconclusive for several reasons, such as interethnic differences. Validation of results in larger cohorts and new populations is needed. The aim of this study is to evaluate the associations between the allelic variants of the eNOS rs1799983 single-nucleotide polymorphism, IHD susceptibility and its clinical presentation. Methods: A total of 362 consecutive patients with suspected myocardial ischemia were enrolled. Patients were divided into three groups: G1, coronary artery disease (CAD); G2, coronary microvascular dysfunction (CMD); and G3, a control group with anatomically and functionally normal coronary arteries. Analysis of three allelic variants, GT, GG and TT, of rs1799983 for the NOS3 gene, encoding for eNOS, was performed. Results: rs1799983_GT was significantly more expressed by the ischemic groups (G1 and G2) compared to G3. The TT variant was significantly more expressed by the G1 group, compared to the G2 group. Among ischemic patients, GT was significantly more expressed in patients with acute coronary syndrome (ACS) presentation, compared to other clinical presentations. In the multivariate analysis, the allelic variant GT was found to potentially represent an independent predictor of IHD and ACS presentation. Conclusion: The presence of the SNP rs1799983_GT, encoding for eNOS, is an independent risk factor for IHD and, remarkably, for ACS presentation, independently of cardiovascular risk factors. These results may be useful for the prediction of IHD development, particularly with an acute clinical manifestation. They may allow the early identification of patients at high risk of developing IHD with an ACS, promoting a genetic-based prevention strategy against IHD.

Among the most common causes of death worldwide, ischemic heart disease (IHD) is recognized to rank first. Even if atherosclerotic disease of the epicardial arteries is known as the leading cause of IHD, the presence of myocardial infarction with non-obstructive coronary artery disease (MINOCA) is increasingly recognized. Notwithstanding the increasing interest, MINOCA remains a puzzling clinical entity that can be classified by distinguishing different underlying mechanisms, which can be divided into atherosclerotic and non-atherosclerotic. In particular, coronary microvascular dysfunction (CMD), classifiable in non-atherosclerotic mechanisms, is a leading factor for the pathophysiology and prognosis of patients with MINOCA. Genetic susceptibility may have a role in primum movens in CMD. However, few results have been obtained for understanding the genetic mechanisms underlying CMD. Future studies are essential in order to find a deeper understanding of the role of multiple genetic variants in the genesis of microcirculation dysfunction. Progress in research would allow early identification of high-risk patients and the development of pharmacological, patient-tailored strategies. The aim of this review is to revise the pathophysiology and underlying mechanisms of MINOCA, focusing on CMD and actual knowledge about genetic predisposition to it.

Heart failure with preserved ejection fraction (HFpEF) is a complex clinical syndrome responsible for high mortality and morbidity rates. It has an ever growing social and economic impact and a deeper knowledge of molecular and pathophysiological basis is essential for the ideal management of HFpEF patients. The association between HFpEF and traditional cardiovascular risk factors is known. However, myocardial alterations, as well as pathophysiological mechanisms involved are not completely defined. Under the definition of HFpEF there is a wide spectrum of different myocardial structural alterations. Myocardial hypertrophy and fibrosis, coronary microvascular dysfunction, oxidative stress and inflammation are only some of the main pathological detectable processes. Furthermore, there is a lack of effective pharmacological targets to improve HFpEF patients’ outcomes and risk factors control is the primary and unique approach to treat those patients. Myocardial tissue characterization, through invasive and non-invasive techniques, such as endomyocardial biopsy and cardiac magnetic resonance respectively, may represent the starting point to understand the genetic, molecular and pathophysiological mechanisms underlying this complex syndrome. The correlation between histopathological findings and imaging aspects may be the future challenge for the earlier and large-scale HFpEF diagnosis, in order to plan a specific and effective treatment able to modify the disease’s natural course.