View clinical trials related to Coronary Vasospasm.
Filter by: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.
This study was recommended by NICE, as part of its 2006 guidance for the treatment of hypertension, and is urgently required to provide evidence for the treatment recommendations in patients with resistant hypertension. The study will be a randomised placebo-controlled double-blind crossover comparison of an α-blocker (α), β-blocker (β), and K+-sparing diuretic (∆). Patients will have a BP at entry above target on ABPM or home monitoring despite supervised administration of maximum tolerated doses of A+C+D. Over 48 weeks they will then receive, in random order either placebo or two doses each of doxazosin (α), bisoprolol (β) or spironolactone (∆). Each treatment cycle will last 12 weeks, with a forced dose-doubling at 6 weeks. The time course for the study will be similar to study one. 340 patients will provide 90% power, at α=0.01 to detect a 3 mmHg overall difference in home sBP between any one drug and placebo, with spironolactone hypothesized to be best overall. The study will be able to detect a 6 mmHg difference in sBP between each subject's best and second-best drug predicted by tertile of plasma renin, justifying routine use of the measurement in patients with resistant hypertension.
The TIVUS II is a prospective, multicenter, non-randomized, open-label clinical study of the safety and performance of the TIVUS™ System consisting of three (3) concurrent cohorts: - TIVUS™ Severe Resistant HTN Cohort - TIVUS™ Moderate Resistant HTN Cohort - TIVUS™ Failed RF Therapy Cohort
Hypertension is still one of the major preventable risk factor for cardiovascular as well as cerebrovascular diseases globally, including ischaemic heart disease, heart failure, and renal impairment. Despite knowledge on hypertension and the availability of effective antihypertensive medications have progressed dramatically in recent years, the rate of uncontrolled hypertension ( reached 90%) remains high in China[1]. Among those with uncontrolled hypertension，it has been reported that 8.9% in all individuals with hypertension, and 12.8% in the hypertensive drug-treated population[2] are attributed to resistant hypertension. Resistant hypertension has been defined by AHA as high blood pressure (BP) in spite of appropriate lifestyle interventions and treatment of three or more different types of antihypertensive drugs at optimal dose, including at least one diuretics[3,4] or achieving adequate BP control with optimal doses of 4 or more antihypertensive drugs. At present, not many specifically designed prospective researches concerning resistant hypertension are available. The prevalence of resistant hypertension is not well established and most knowledge about resistant hypertension derives from cross-sectional analyses and clinical trials. The patients with resistant hypertension have been expected to have server target damage, and worse prognosis than those who are non-resistant, but not well established either in the literature[2]. The purpose of this study is to determine the prevalence of resistant hypertension ascertained with systemic investigation and optimal treatment with antihypertensive drugs in community populations and clinic as well as the prognosis among patients with resistant hypertension compared with those who are non-resistant.
The purpose of this study is to demonstrate that Renal Sympathetic Denervation (RDN) improves the control of blood pressure (BP) in patients with treatment-resistant hypertension, as compared to intensive medical therapy (IMT) using hemodynamic parameters and then applying a predefined algorithm of drug selection (i.e. integrated hemodynamic management - IHM) during 6 months intensive treatment program (receiving antihypertensive care according to the 2007 ESH Guidelines). Working hypothesis: When it is possible to disrupt the sympatho-renal axis by RDN - BP reduction occurs to a greater extent and more rapidly than applying intensive medical therapy using IHM.