Active clinical trials for "Microvascular Angina"

The goal of this clinical trial is to assess the feasibility and clinical value of acetylcholine (ACH) rechallenge after intracoronary verapamil +- nitroglycerine in a patient cohort with angina and non-obstructive coronary arteries (ANOCA). The main questions it aims to answer are: to determine the efficacy of these drugs in treating ACH-induced coronary artery spasm to determine the efficacy of these drugs in preventing ACH-induced coronary artery spasm The ACH rechallenge will take place during the index coronary function tests in patients with proven ACH-induced vasospastic angina. The study is considered a feasibility study, no control arm is included.

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.

Among patients with stable ischemic heart disease who are referred for coronary angiography, a substantial proportion have non-obstructive coronary artery disease (CAD). Ischemia based on symptoms or stress testing may be due to coronary microvascular dysfunction in up to 40% of these patients. However, the mechanisms and optimal treatment of coronary microvascular dysfunction are unknown. Aberrant platelet activity and inflammation have been hypothesized as mechanisms of microvascular dysfunction. Investigators plan to evaluate association between platelet activity, inflammation, and coronary microvascular dysfunction in stable women referred for coronary angiography, and to identify non-invasive correlates of coronary microvascular dysfunction in these patients.

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.

In patients with chest pain and/or shortness of breath coronary artery disease (CAD) is suspected depending on the pattern of symptoms and the electrocardiogram (ECG). Coronary angiography is the method of choice to verify this suspicion. If the patient coronary arteries on coronary angiography are totally normal or unobstructed, one can only speculate if the patients' discomfort is from the heart or not. A possibility to get further information about the healthiness of the coronary arteries is the acetylcholine test (ACH-test). When injecting this natural, body produced-substance into the coronary arteries one can test if the vessels develop coronary spasm which can be the reason for the patient's symptoms. The investigators therefore use this test in this study to look for coronary spasm in patients with suspected CAD but normal/unobstructed coronary arteries. In case of a positive test, the patient profits from having found a cause for his/her symptoms making treatment with special tablets possible. Furthermore, the investigators want to analyze blood samples of every patient to look for signs of inflammation, vasoconstriction and genetic variants that seem to be linked with coronary spasms. On the basis of these results the ACH-test could probably be avoided in the future.

Coronary artery microvascular disease (CMVD) lacks reliable and non-invasive quantitative diagnosis methods. Improving coronary microcirculation has become one of the main goals of coronary heart disease treatment. In this study, by establishing the key influencing factors of myocardial microcirculation perfusion, an accurate three-dimensional reconstruction method of coronary artery was established, and a non-invasive coronary microcirculation resistance index (CT-IMR) calculation method based on computational fluid method mechanics was established. At the same time, a phase I single-center clinical verification and a multi-center clinical verification of the non-invasive coronary microcirculation function precision assessment system were carried out, and a non-invasive coronary microcirculation detection system and technology were established.

Exercise CMD is a prospective single-center, open-label, parallel arms randomized controlled trial. This trial aims to assess the impact of cardiac rehabilitation on top of optimal medical therapy on patient-reported outcomes in subjects with coronary microvascular disease and non-obstructive coronary artery disease. Patients will undergo a microvascular assessment using bolus thermodilution techniques and those with criteria for microvascular angina (IMR ≥ 25) will be invited to participate. Patients will be randomized in a 1:1 ratio to either optimal medical therapy (OMT) or OMT plus a program of cardiac rehabilitations (CR). After randomization, spiro-ergometry and a SAQ-19 will be performed in all patients. Medical therapy will be standardized in both arms and the CR group will follow 36 sessions of the personalized physical training program of cardiac rehabilitation. Approximately 204 subjects (102 in each group) will be included at one site (OLV Aalst, Belgium). Clinical Follow-Up will be planned at 4 months. Patients with CCTA performed in standard of care will be invited for control CCTA 6 +/- 1 month after the invasive procedure.

The MINOCA-GR registry will be the first nationwide study aiming to obtain data regarding prevalence, demographics, clinical profile, previous anginal status, presence of cardiovascular risk factors, management and outcomes in patients with Myocardial Infarction with Non-Obstructive Coronary Arteries. An additional purpose of the registry is to highlight, for the first time worldwide to the best of the investigator's knowledge, the role of cardiac computed tomography angiography for risk stratification and personalized therapeutic approach in MINOCA patients.

The last 15 years the introduction of primary angioplasty has radically improved outcomes for acute myocardial infarction (AMI). However, the system wide availability of prompt investigation has revealed an important group of patients where progress has stalled, the diagnosis is unclear and therapeutic approaches are uncertain. Myocardial infarction with non-obstructive coronary arteries (MINOCA) is found in 1 - 13% of all patients with a clinical diagnosis of AMI. These patients present a therapeutic predicament since coronary revascularization is not appropriate. Guidelines do not exist for their management - yet the condition is not benign - the 12-month prognosis, although better than obstructive coronary artery disease patients is still guarded with recent data suggesting many questions remain unanswered.

To investigate the efficacy and safety of Tongxinluo in patients with microvascular angina pectoris. Long-term follow-up of 1 to 5 years will be performed to evaluate the effect of Tongxinluo on long-term adverse cardiovascular events in patients with coronary microvascular disease.