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19 clinical studies listed.

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Microvascular Angina

Tundra lists 19 Microvascular Angina clinical trials. Each listing includes eligibility criteria, study locations, and direct links to research sites in the Tundra directory.

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RECRUITING

NCT04674449

iCorMicA - Stratified Medicine in Angina

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.

Gender: All

Ages: 18 Years - Any

Updated: 2026-04-09

1 state

Microvascular Angina
Angina, Stable
Ischemia With No Obstructive Coronary Arteries (INOCA)
+7
NOT YET RECRUITING

NCT07449325

Self Expanding Coronary Sinus Reducer for Treatment of Symptomatic Coronary Microvascular Dysfunction (CMD)

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.

Gender: All

Ages: 18 Years - Any

Updated: 2026-03-04

Angina Pectoris
Myocardial Ischemia
Heart Diseases
+3
ACTIVE NOT RECRUITING

NCT06025994

Standardizing the Management of Patients With Coronary Microvascular Dysfunction

The SAMCRO is an all comers, prospective, randomized, multicenter, open-label study with blinded adjudicated evaluation of outcomes (PROBE). The diagnosis of angina in non obstructive coronary artery disease (ANOCA) will be confirmed with coronary artery angiography and with the invasive assessment of coronary microvascular dysfunction (CMD) and coronary vasomotion. At least 120 ANOCA patients with invasively confirmed CMD will be randomized to i) multi-domain lifestyle intervention (experimental arm) vs. ii) standard of care (control arm). All patients will undergo follow-up visits at 6, 12, 24, 36, 48 and 60 months. The study endpoints will be the improvement of angina status and quality of life as assessed by validated questionnaires at one year. All participants in the multi-domain lifestyle group will receive five different kinds of intervention: i) dietary counselling, ii) strict management of cardiovascular (CV) and metabolic risk factors, iii) tailoring of medical therapy on the basis of the invasive assessment of CMD and coronary vasomotion, iv) exercise training and v) psychological intervention. Patients randomized to the control group will be managed according to current guidelines. The angina status will be assessed by the Seattle Angina Questionnaire (SAQ). Quality of life will be assessed using the EuroQoL (EQ5D-5L). Anxiety and depression will be assessed using the Beck Depression Inventory (BDI).

Gender: All

Ages: 18 Years - Any

Updated: 2026-02-19

2 states

Coronary Artery Disease
Microvascular Angina
Microvascular Ischemia of Myocardium
RECRUITING

NCT06692751

The Value of Measuring Retinal Vascular Density by Optical Coherence Tomography-Angiography (OCT-A) in Patients With Microvascular Angina Confirmed by Myocardial Microcirculatory Resistance Index (MRI).

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.

Gender: All

Ages: 18 Years - Any

Updated: 2026-02-17

Microvascular Angina
ACTIVE NOT RECRUITING

NCT05288361

The DISCOVER INOCA Prospective Multi-center Registry

The overall objective of this multi-center registry is to identify specific phenotypes of INOCA with both an anatomic evaluation (coronary angiography and intravascular imaging) and physiologic assessment with the Abbott Coroventis Coroflow Cardiovascular System, and to determine long-term outcomes.

Gender: All

Ages: 18 Years - Any

Updated: 2025-12-18

6 states

Ischemia and No Obstructive Coronary Artery Disease
Coronary Microvascular Dysfunction
Coronary Vasospasm
+3
ACTIVE NOT RECRUITING

NCT05619653

Myocardial Protection in Patients With Post-acute Inflammatory Cardiac Involvement Due to COVID-19

Long COVID or Postacute sequelae of COVID-19 infection (PASC) are increasingly recognised complications, defined by lingering symptoms, not present prior to the infection, typically persisting for more than 4 weeks. Cardiac symptoms due to post-acute inflammatory cardiac involvement affect a broad segment of people, who were previously well and may have had only mild acute illness (PASC-cardiovascular syndrome, PASC-CVS). Symptoms may be contiguous with the acute illness, however, more commonly they occur after a delay. Symptoms related to the cardiovascular system include exertional dyspnoea, exercise intolerance chest tightness, pulling or burning chest pain, and palpitations (POTS, exertional tachycardia). Pathophysiologically, Long COVID relates to small vessel disease (endothelial dysfunction) vascular dysfunction and consequent tissue organ hypoperfusion due to ongoing immune dysregulation. Active organs with high oxygen dependency are most affected (heart, brain, kidneys, muscles, etc.). Thus, cardiac symptoms are often accompanied by manifestations of other organ systems, including fatigue, brain fog, kidney problems, myalgias, skin and joint manifestations, etc, now commonly referred to as the Long COVID or PASC syndrome. Phenotypically, PostCOVID Heart involvement is characterised by chronic perivascular and myopericardial inflammation. We and others have shown changes using sensitive cardiac MRI imaging that relate to cardiac symptoms (Puntmann et al, Nature Medicine 2022; Puntmann et al, JAMA Cardiol 2020; Summary of studies included in 2022 ACC PostCOVID Expert Consensus Taskforce Development Statement, JACC 2022, references below). Early intervention with immunosuppression and antiremodelling therapy may reduce symptoms and development of myocardial impairment, by minimising the disease activity and inducing disease remission. Low-dose maintenance therapy may help to maintain the disease activity at the lowest possible level. The benefits of early initiations of antiremodelling therapy to reduce symptoms of exercise intolerance are well recognised, but not commonly employed outside the classical cardiology contexts, such as heart failure or hypertension. As most patients with inflammatory heart disease only have mild or no structural abnormalities, they are left untreated (standard of care). The aim of this study is to examine the efficacy of a combined immunosuppressive / antiremodelling therapy in patients with PASC symptoms and inflammatory cardiac involvement determined by CMR, to reduce the symptoms and inflammatory myocardial injury and thereby stop the progression to reduced LVEF, HF and death.

Gender: All

Ages: 18 Years - 65 Years

Updated: 2025-12-09

1 state

COVID-19 Associated Cardiac Involvement
Remodeling, Left Ventricle
Remodeling, Vascular
+6
RECRUITING

NCT07196397

POLish Registry of CArdioneuroablation and CArdioneuromodulation

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.

Gender: All

Ages: 18 Years - Any

Updated: 2025-09-29

Vasovagal Syndrome VVS
Cardioinhibitory Carotid Sinus Syndrome CSS
Symptomatic Sinus Bradycardia SB or Atrioventricular Block AV
+9
RECRUITING

NCT07103317

Comprehensive Coronary Physiology in Patients With Angina With Nonobstructive Coronary Arteries - Czech Republic

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.

Gender: All

Ages: 18 Years - Any

Updated: 2025-08-05

1 state

ANOCA
ANOCA - Angina With Non-obstructive Coronary Arteries
MINOCA
+4
RECRUITING

NCT06681896

Microvascular Coronary Rehabilitation For Improving Treatment - Feasibility Study

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.

Gender: All

Ages: 18 Years - Any

Updated: 2025-06-18

Microvascular Coronary Dysfunction
Microvascular Angina
Coronary Microvascular Dysfunction (CMD)
RECRUITING

NCT05492110

Coronary Sinus Reducer Implantation in Patients With Ischaemia and Non-obstructed Coronary Arteries and Coronary Microvascular Dysfunction.

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.

Gender: All

Ages: 18 Years - Any

Updated: 2025-04-03

Refractory Angina
Microvascular Angina
Microvascular Coronary Artery Disease
+2
RECRUITING

NCT06076551

Sex Difference of Coronary Microvascular Dysfunction in Patients With Non-obstructive Coronary Artery Disease

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

Gender: All

Ages: 20 Years - 80 Years

Updated: 2025-03-26

Microvascular Angina
ACTIVE NOT RECRUITING

NCT04805814

Coronary Microvascular Angina Cardiac Magnetic Resonance Imaging (CorCMR) Trial

Anginal symptoms due to ischaemia with no obstructive coronary arteries (INOCA) is a common clinical problem, however, diagnosis and onward management is heterogeneous, and prognosis is affected. Recent advances in quantifying myocardial blood flow using stress perfusion cardiac magnetic resonance imaging (CMR) has potential for accurate detection coronary microvascular dysfunction. The CorCMR diagnostic study involves stress perfusion CMR in patients with suspected INOCA to clarify the prevalence of subgroups of patients with underlying problems, such as microvascular disease or undisclosed obstructive coronary artery disease, that might explain their anginal symptoms. A nested, prospective, randomised, controlled, double-blind trial will determine whether stratified medical therapy guided by the results of the stress perfusion CMR improves symptoms, well-being, cardiovascular risk and health and economic outcomes.

Gender: All

Ages: 18 Years - Any

Updated: 2025-01-30

2 states

Microvascular Angina
Angina Pectoris
Angina, Stable
+3
RECRUITING

NCT06070662

Non-invasive Diagnosis of Coronary Microvascular Disease: Pilot Study

* 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.

Gender: All

Ages: 18 Years - Any

Updated: 2024-12-05

1 state

Microvascular Angina
RECRUITING

NCT06424834

Efficacy of Targeted Medical Therapy in Angina and Nonobstructive Coronary Arteries

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.

Gender: All

Ages: 18 Years - Any

Updated: 2024-11-27

1 state

Angina Pectoris
Microvascular Angina
Vasospastic Angina
+1
ACTIVE NOT RECRUITING

NCT03477890

Coronary Microvascular Function and CT Coronary Angiography (CorCTCA)

Angina in patients without obstructive coronary artery disease (CAD) is a clinical conundrum and patient management is heterogeneous. Hypothesis: Abnormal coronary function is common and clinically relevant in this population. Design: An observational cohort study and nested randomised controlled diagnostic strategy trial. Methods: 250 patients with known or suspected angina informed by validated questionnaires but without obstructive CAD (\<70% stenosis) in an artery \>=2.5 mm or structural heart disease, as revealed by CT coronary angiography (CTCA), will be invited to undergo coronary function testing (FFR, CFR, IMR; intra-coronary ACh) during invasive angiography. Patients will be randomised following angiography but before testing coronary function to disclosure of the coronary function test results or not. Treatment decisions by the attending cardiologist will be recorded before and after disclosure of results. Outcomes: Primary: The between-group difference in the reclassification rate of the initial diagnosis using logistic regression, adjusted for baseline factors associated with the likelihood of reclassification of the initial diagnosis. Secondary: Prevalence of microvascular or vasospastic angina; health status reflected by the EuroQol group 5-Dimensions (EQ-5D), Seattle Angina Questionnaire, Illness perception, treatment satisfaction questionnaires and functional status questionnaires; angina medication and adherence. Value: This research will provide new insights into the conundrum of angina in patients without obstructive CAD or structural heart disease.

Gender: All

Ages: 18 Years - Any

Updated: 2024-10-29

3 states

Angina, Stable
Angina Pectoris, Variant
Microvascular Angina
RECRUITING

NCT06401291

Transcutaneous Electrical Nerve Stimulation in Patients With Angina and Non-Obstructive Coronary Arteries

In patients with angina pectoris undergoing a coronary angiography (CAG) up to 40% do not have obstructive coronary artery disease (CAD). The majority of patients with no obstructive CAD are women with a frequency of up to 70% compared to 50% in men. These patients are diagnosed as having angina and non-obstructive coronary arteries (ANOCA). There are two endotypes of ANOCA. The first endotype is microvascular angina (MVA) caused by a combination of structural microcirculatory remodelling and functional arteriolar dysregulation, also called coronary microvascular dysfunction (CMD). The second endotype is vasospastic angina (VSA) caused by epicardial coronary artery spasm that occurs when a hyper-reactive epicardial coronary segment is exposed to a vasoconstrictor stimulus. Both endotypes of ANOCA are associated with significantly greater one-year risk of myocardial infarction (MI) and all-cause mortality, have a significantly impaired quality of life and have a high health care resource utilisation. The current treatment for ANOCA consists of three aspects. The first aspect is managing lifestyle factors such as weight management, smoking cessation and exercise. The second aspect is managing known cardiovascular risk factors such as hypertension, dyslipidaemia and diabetes mellitus. And the third aspect is antianginal medication. In both endotypes ACE inhibitors or angiotensin II receptor blockers should be considered. In MVA the antianginal medication that can be used are betablocker, calcium channel blocker, nicorandil, ranolazine, ivabradine and/or trimetazidine. In VSA calcium channel blocker, long-acting nitrate and/or nicorandil can be initiated as antianginal therapy. Despite these treatment option approximately 25% of ANOCA patients have refractory angina symptoms. A possible treatment modality for ANOCA patients with refractory angina pectoris is spinal cord stimulation (SCS) or transcutaneous electrical nerve stimulation (TENS). Previous research (in patients with cardiac syndrome X) has shown that SCS improves time until angina and ischaemia, significantly less angina and an improvement in quality of life. These findings suggest that SCS and/or TENS could be a possible treatment modality for patients with ANOCA. The aim of this pilot study is to investigate whether treatment with TENS during a one month period leads to a significant reduction of angina pectoris and therefore a significant improvement in quality of life in patients with proven ANOCA, encompassing both endotypes (MVA and VSA).

Gender: All

Ages: 18 Years - Any

Updated: 2024-05-06

1 state

Microvascular Angina
Vasospastic Angina
RECRUITING

NCT06243653

Relationship Between Coronary Microvascular Dysfunction and Improvement of Left Ventricular Systolic Function in Patients With Heart Failure With Reduced Ejection Fraction Caused by Non-ischemic Etiology

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.

Gender: All

Ages: 19 Years - Any

Updated: 2024-02-06

Heart Failure
Microvascular Angina
Non-ischemic Cardiomyopathy
RECRUITING

NCT06092736

Microvascular Angina Intervention With Compound Danshen Dripping Pill (MAIDS)

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.

Gender: All

Ages: 30 Years - 75 Years

Updated: 2023-10-23

1 state

Microvascular Angina
ACTIVE NOT RECRUITING

NCT04777045

Efficacy of Diltiazem to Improve Coronary Microvascular Dysfunction: a Randomized Clinical Trial

Rationale: Up to 40% of patients undergoing a coronary angiogram for symptoms/signs of ischemia do not have obstructive coronary artery disease (CAD). In about half of them the mechanism underlying cardiac ischemia is coronary microvascular dysfunction (CMD). In CMD, myocardial ischemia is caused by impaired endothelial and/or non-endothelial coronary vasoreactivity resulting in the coronary microvasculature not dilating properly or becoming vasospastic. Recently published diagnostic criteria state that to confirm the diagnosis, CMD patients should either have an impaired coronary flow reserve (CFR), increased microvascular resistance (IMR) or have evidence of microvascular spasms. Hence, invasive coronary function testing (CFT) is considered the reference standard for a definitive diagnosis of CMD. Patients with microvascular angina often have continuing episodes of chest pain leading to frequent first aid visits and hospital re-admissions with associated high health care costs. Moreover, CMD is associated with a worsened cardiovascular prognosis. Therefore, adequate treatment is paramount. However, current treatment options are based on a limited number of small studies, most of which were not placebo-controlled. Based on prior studies and our clinical experience we believe diltiazem, a calcium channel blocker (CCB) could improve coronary microvascular function in patients with CMD. Objective: Our primary objective is to assess the effect of diltiazem on coronary microvascular function as assessed by CFT in symptomatic patients with CMD. Our secondary objective is to assess the effect of diltiazem on the individual coronary function parameters. Study design: This is a clinical multi-center randomized with 1:1 ratio, double-blind, placebo-controlled study. Patients with chronic angina in the absence of obstructive CAD will be screened for study enrollment. Eligible patients will be asked for informed consent after which the screening visit will take place. Within 8 weeks after screening they will undergo CFT with the assessment of the coronary flow reserve (CFR), index of microcirculatory resistance (IMR) and coronary spasm. * Intervention arm: if CFT shows either a CFR ≤ 2.0, an IMR ≥ 25 and/or coronary spasm, the patient will continue in the intervention arm of the trial and will be randomized to either diltiazem or placebo treatment for 6 weeks. After 6 weeks, a CFT will be repeated and the diltiazem/placebo treatment will be discontinued. Follow-up will be obtained after 6 weeks of treatment, and 1 year and 5 years after treatment discontinuation. * Registration arm: If the CFT at baseline shows no signs of vascular dysfunction, patients will enter in the registration arm of the study. These patients will not receive any study medication. Follow-up will be obtained after 1 year and 5 years. Study population: Adult patients with chronic angina in the absence of obstructive CAD will be screened for participation. They will be recruited from the outpatient clinic of the cardiology department of the participating sites. Patients with contra-indications for coronary function testing (with the use of adenosine and acetylcholine) and/or diltiazem treatment (i.e. severe AV conduction delay, hypersensitivity, reduced left ventricular function) will not be eligible. Intervention: After establishing an abnormal coronary vascular function, 6 weeks treatment with either diltiazem 120-360 mg or placebo will be initiated in a double-blind fashion. Every two weeks dose titration will be performed if possible, under the guidance of patient tolerance (dizziness, leg oedema, etc.), blood pressure and heart rate. Main study parameters/endpoints: The proportion of patients having a successful treatment with diltiazem, defined as normalization of at least one abnormal parameter and none of the normal parameters becoming abnormal.. A normal IMR is specified as IMR \< 25, a normal CFR being a CFR \> 2 and a normal acetylcholine test is specified as one without ECG abnormalities and without signs of spasm at the same acetylcholine dose used at baseline. Main secondary endpoints will be the change in the individual coronary function parameters. Nature and extent of the burden and risks associated with participation, benefit and group relatedness: The extensive experience with diltiazem and the favourable safety profile in combination with the short duration of treatment make the treatment risk low for participants. Related to the study procedure several reports show that CFT is a safe procedure with serious complication rates (death, myocardial infaction, etc.) ranging from 0 to 0.7%. The first CFT is clinically indicated by the treating physician. The second CFT will bring additive risk to the participants in the intervention arm. However, we believe it is essential to investigate the effect of diltiazem on coronary function to justify its use in CMD patients.

Gender: All

Ages: 18 Years - Any

Updated: 2023-03-30

1 state

Microvascular Angina
Coronary Vasospasm
Microvascular Ischemia of Myocardium