Microvascular Angina

VahatiCor's Coronary Sinus Reducer (A-FLUX) has been designed to improve angina or angina-like symptoms in patients with CMD. SERRA-I is an early feasibility study that evaluates the safety and clinical performance of the A-FLUX Reducer in this population.

* 40% of patients presenting with stable chest pain (angina) have no significant blockage of the main heart arteries. Identifying why these patients have symptoms will mean better treatment options can be developed. * About 60% of these patients have evidence of coronary microvascular disease (CMD). In this condition there is a problem with the heart's microvessels (very small blood vessels that branch from the main heart arteries). Due to problems with these vessels there is a mismatch between the blood supply to the heart and its oxygen consumption, causing chest pain and this can also lead to major heart events. * At present, to diagnose this condition, specialised techniques during an invasive test, called a coronary angiogram, are required. As this is an invasive test, it can be lead to complications and cause discomfort. * Non-invasive ways of diagnosing CMD are required to improve the diagnosis and management of this condition. * This study aims to provide initial data on whether novel imaging techniques using CT and MRI scans, which are much less invasive, could identify CMD. * To do this, patients with suspected angina referred for angiography and who are already participants in the main research study 'CMR versus CT-FFR in CAD' study will be recruited. * These will be patients with suspected CMD and also those with blockage of the main heart arteries (triple vessel disease) to compare against. * Participants in this pilot study will have additional tests used to diagnose CMD during their invasive angiography procedure. Participants will then have an MRI scan involving novel techniques and exercise MRI, where individuals exercise use a cycle or stepping machine during the MRI scan. Further analysis will also be undertaken of CT images acquired as part of the main study. * These tests will be compared against invasive test results to see which show potential in being able to diagnose CMD.

The iCorMicA study is a multicentre, prospective, randomised, double-blind, sham-controlled, parallel-group, end-point trial and registry. The investigators seek to determine whether stratified medical therapy guided by an adjunctive interventional diagnostic procedure (IDP) during the invasive management of patients with known or suspected angina but no obstructive coronary artery disease improves symptoms, wellbeing, cardiovascular risk and clinical outcomes.

Microvascular angina is thought to affect around 112 million patients worldwide. However, this figure is underestimated due to the difficulty of making the diagnosis. It is a pathology caused by an alteration in the microcirculation of the heart muscle, which is not detectable on a standard coronary angiogram. In view of its prognostic, therapeutic and medico-economic value, scientific societies currently recommend invasive measurement of the microcirculatory resistance index (MRI) to diagnose microvascular angina, in the absence of significant lesions on coronary angiography. Several research teams, including our own, have shown that cardiovascular risk is associated with alterations in the vascularization of the small vessels (microcirculation) of the retina. Unlike the study of cardiac vessels, the study of retinal microcirculation using fundus photography (OCT-A) is simple, rapid, non-invasive and inexpensive. It appears to be an interesting alternative to the measurement of IMR for the diagnosis of microvascular angina. This hypothesis has never yet been tested. The demonstration of an association between a decrease in retinal vascular density measured by OCT-A and an alteration in coronary microvascular function measured by IMR would pave the way for a completely non-invasive diagnosis of patients. This is an observational, cohort, prospective, single-center pilot study comparing people who have received an IMR measurement as part of INOCA. It is planned to include 158 participants. The overall follow-up period for each patient in the research is 12 months. In routine care, IMR is measured during coronary angiography in patients presenting with ischemia on a non-invasive test and/or stress symptoms such as angina or dyspnea, for whom coronary angiography does not reveal any significant epicardial lesion. Following this examination, two groups will be formed: a group with an IMR\<25 and a group with an IMR≥25. Clinically, the study aims to determine the potential role of retinal OCT-A as a non-invasive examination for the diagnosis and/or follow-up of INOCA.

The multicentre observational study POL-CA involves a wide spectrum of patients with a history of syncopy. The study recruits patients with diagnosed vasovagal syndrome, cardioinhibitory carotid sinus syndrome, symptomatic sinus bradycardia or atrioventricular block, postural orthostatic tachycardia syndrome, orthostatic hypotension, and inappropriate sinus tachycardia syndrome. This is an observational, controlled study with retrospective, clinical data analysis of previously treated patients and the analysis of syncopal patients prospectively recruited into the study. The aim of the POL-CA registry is to create a platform for physicians to record treatment data for patients undergoing procedures that affect innervation or modify cardiovascular reflexes (cardioneuroablation, cardioneuromodulation) in order to provide a multicentre summary of population characteristics and treatment outcomes based on a standardized POL-CA questionnaire and methodology for various arrhythmias.

Coronary artery disease (CAD) is a leading cause of morbidity and mortality. While cardiologists have been focused on discrete, visible stenoses of coronary arteries, there is increasing awareness of the importance of microcirculation and vasospastic disorders in causing angina. The microvascular bed is composed of vessels smaller than 400 microns in diameter. Their network is significantly larger than that of the epicardial vessels and serves essential functions, including regulating myocardial blood flow and cellular metabolism. Angina pectoris, a most frequent symptom of CAD or myocardial ischemia, was assumed to be caused by significant stenosis of the epicardial coronary artery. However, it was found that in over 50% of cases, there was no obstructive CAD, which is described as angina with no obstructive coronary arteries (ANOCA) or ischemia with no obstructive coronary arteries (INOCA), according to the clinical setting.

The goal of this clinical trial is to assess the feasibility of undertaking a randomized controlled trial assessing the impact of a personalised, intense cardiac rehabilitation programme involving high intensity interval exercise (HIIT) and dietary advice (termed MICROFIT) on symptom burden in patients with microvascular coronary dysfunction. The main questions it aims to answer are: 1. Feasibility of undertaking randomised controlled trial of MICROFIT in patients with coronary microvascular dysfunction (recruitment rates, retention and adherence, acceptability of MICROFIT and participants' and practitioners' experiences of trial participation) 2. Preliminary data on the effect that MICROFIT has on angina symptoms in patients with microvascular coronary dysfunction, as measured by Seattle Angina Questionnaire 3. Preliminary data on the fidelity and clinical efficacy of MICROFIT Participants will be randomized to either MICROFIT + Usual Care, or Usual Care group. Participants in both arms of the trial will: * Undergo a series of investigations, including cardiopulmonary exercise test (CPET), dual xray absorptiometry (DEXA), echocardiogram, cardiac MRI scan, blood tests, at the start of the trial and again after 6 months * Measure their living activity by using an activity tracker (GeneActiv) as well as a photographic diet diary for a week at the start of the trial and again after 6 months * Complete a series of questionnaires to assess angina symptom burden, mental health and quality of life, at the start of the trial and again after 6 months. Participants in the intervention arm of the study will: 1. Undergo MICROFIT intervention. MICROFIT includes a combination of exercise and diet management sessions over 24 weeks. It involves: * 1:1 high-intensity interval training ('HIIT') sessions with a personal trainer and guidance on exercise sessions to be performed at home * 1:1 sessions with a dietician to support them with improvements in diet. 2. Visit clinic on two additional occassions during the trial to discuss their progress with a cardiologist 3. Undergo an interview at the end of the study to discuss their experiences of participation in the study 4. Receive a debrief on their investigation results and progress made at the end of their study Participants in the Usual Care arm of the study will: 1. Receive standard Usual Care advice regarding lifestyle changes and targeted medical therapy offered to patients with coronary microvascular dysfunction. 2. Receive a debrief on their investigation results and progress made at the end of their study 3. Undergo a 'taster' session with the personal trainer to discover what the intervention involves.

To demonstrate the feasibility and efficacy of the CS Reducer for the treatment of patients with ischaemia and non-obstructed coronary arteries (INOCA) and coronary microvascular dysfunction (CMD) and through a nested mechanistic substudy investigate the physiological responses in the coronary microcirculation responsible for changes in myocardial perfusion.

Sex difference of coronary microvascular dysfunction evaluated by coronary flow reserve will be assessed in patients with non-obstructive coronary artery disease

The goal of this clinical trial is to learn if targeted medical therapy will improve symptoms and quality of life in patients with angina and non-obstructive coronary arteries compared to placebo, after the underlying cause of the chest pain has been ascertained by coronary function testing. Participants will be treated with either medications that target the underlying cause of their chest pain or placebo for 4 weeks after a drug titration phase of 1-3 weeks. They will be asked to complete a series of questionnaires to evaluate their quality of life at the beginning and end of the study.

This study aims to evaluate the incidence of coronary microvascular dysfunction (CMD) and its prognostic implication for the improvement of left ventricular function in patients who have been diagnosed with heart failure with reduced ejection fraction (HFrEF) caused by non-ischemic etiology.

Coronary microvascular disease (MVD) refers to exertional angina or myocardial ischemia caused by abnormal structure and/or function of precoronary arterioles and arterioles under the action of various pathogenic factors. The symptoms of patients with coronary microvascular disease are mainly exertion-related chest pain episodes. The basic and clinical researches of the traditional Chinese medicine compound Danshen dropping pills have found that it can improve vascular endothelial function and relieve angina pectoris, and it is widely used in clinical practice. This is a randomized, double-blind, placebo-controlled, multicenter clinical study of Compound Danshen Dropping Pills and blank control in patients with microvascular angina pectoris. The experimental drug and control drug of this clinical trial were selected according to the ratio of 1:1 patients were enrolled in the pre-experiment. After the selected patients signed the informed consent, they were divided into a compound Danshen dripping pill treatment group and a placebo group according to a random, double-blind, placebo-controlled method. Dosage of Compound Danshen Dropping Pills or placebo: 20 capsules each time, 3 times a day, for a total of 6 months. Follow-up was performed every 2 months for a total of 6 months. Primary study endpoints is the difference of the left anterior descending coronary flow reserve (CFR) measured by ultrasound between the two groups compared with the baseline. Secondary study endpoint include the Number of angina attacks per week, the time of angina pectoris and the time of ischemic ST segment depression in exercise test.