No abstract

Many patients with chest pain undergoing coronary angiography do not show significant obstructive coronary lesions. A substantial proportion of these patients have abnormalities in the function and structure of coronary microcirculation due to endothelial and smooth muscle cell dysfunction. The coronary microcirculation has a fundamental role in the regulation of coronary blood flow in response to cardiac oxygen requirements. Impairment of this mechanism, defined as coronary microvascular dysfunction (CMD), carries an increased risk of adverse cardiovascular clinical outcomes. Coronary endothelial dysfunction accounts for approximately two-thirds of clinical conditions presenting with symptoms and signs of myocardial ischemia without obstructive coronary disease, termed “ischemia with non-obstructive coronary artery disease” (INOCA) and for a small proportion of “myocardial infarction with non-obstructive coronary artery disease” (MINOCA). More frequently, the clinical presentation of INOCA is microvascular angina due to CMD, while some patients present vasospastic angina due to epicardial spasm, and mixed epicardial and microvascular forms. CMD may be associated with focal and diffuse epicardial coronary atherosclerosis, which may reinforce each other. Both INOCA and MINOCA are more common in females. Clinical classification of CMD includes the association with conditions in which atherosclerosis has limited relevance, with non-obstructive atherosclerosis, and with obstructive atherosclerosis. Several studies already exist which support the evidence that CMD is part of systemic microvascular disease involving multiple organs, such as brain and kidney. Moreover, CMD is strongly associated with the development of heart failure with preserved ejection fraction (HFpEF), diabetes, hypertensive heart disease, and also chronic inflammatory and autoimmune diseases. Since coronary microcirculation is not visible on invasive angiography or computed tomographic coronary angiography (CTCA), the diagnosis of CMD is usually based on functional assessment of microcirculation, which can be performed by both invasive and non-invasive methods, including the assessment of delayed flow of contrast during angiography, measurement of coronary flow reserve (CFR) and index of microvascular resistance (IMR), evaluation of angina induced by intracoronary acetylcholine infusion, and assessment of myocardial perfusion by positron emission tomography (PET) and magnetic resonance (CMR).

Several studies have shown that depression is an important predictor of morbidity and mortality in patients with ischaemic heart failure. We have investigated whether clinically recognised depression is linked to mortality in patients with non-ischaemic heart failure due to dilated cardiomyopathy (DCM) in the Royal Brompton Hospital (RBH), a tertiary cardiac centre located in London, UK. We retrospectively examined a cohort of 396 consecutive adult patients with DCM who satisfied our inclusion and exclusion criteria identified from an echocardiographic database and the hospital medical records. Mean age was 53"15 years. In all, 83 patients (21%) were clinically depressed, the majority of which (60%) were taking antidepressant therapy. After a follow-up period of 48 months, 83 (21%) patients died, 15 (4%) underwent cardiac transplantation and 130 (33%) were readmitted; 29 (35%) of the deaths and 40 (31%) of the readmissions were among clinically depressed patients. After 5 years, clinically depressed patients had significantly higher mortality and readmission rates than non-depressed; 36 vs. 16% (hazards ratio for death, 3.0; 95% CI, 1.4-6.4; Ps0.004), and 87 vs. 74% (hazards ratio for readmission, 0.25; 95% CI, 0.07-0.90; Ps 0.03), respectively. The risk of depression was greatly increased in the presence of other recognised adverse clinical variables at baseline. Depression increases the risk of death and readmission in patients with heart failure secondary to non-ischaemic DCM. The risk associated with depression appears to be greatest among patients with milder disease, those with a shorter duration of symptoms and those demonstrating a lower systolic or diastolic blood pressure, renal impairment, or a restrictive left ventricular physiology on echocardiography. Interventions targeted at reducing depression warrant further study as a possible way to improve quality of life andyor outcome in patients with heart failure.