To determine the effectiveness of the beta-blocker nebivolol in controlling symptoms and improving the quality of life in patients with angina and coronary microvascular dysfunction.
Objective To determine the effectiveness of the beta-blocker nebivolol in controlling symptoms and improving the quality of life in patients with angina and coronary microvascular dysfunction. Hypothesis Treatment with titrated nebivolol will result superior to placebo in symptoms control in patients presenting with coronary microvascular disease (CMD). Study design Prospective, multicenter, controlled, double-blinded, randomized clinical trial. Inclusion criteria • Patients over 18 years old with symptoms or evidence of myocardial ischemia and coronary arteries without lesions or with epicardial lesions (\<50% by visual estimation or FFR \>0.80 / RFR \>0.90), and • CFR ≤ 2.0 and/or IMR≥25 Exclusion criteria Life expectancy \<1 year, inability to provide informed consent, severe valve disease, left ventricular ejection fraction \<30%, clinical contraindication for betablockers treatment. Treatment arms Randomization will be performed after invasive diagnostic of CMD: Study group: Nebivolol • Patients will start with a dose of 5 mg every 24 hours. Biweekly dose adjustments will be performed during the first two months, increasing the dose (if tolerated with respect to heart rate, blood pressure, and symptoms) up to a maximum of 20 mg/24 hours. Control group: Placebo • Patients will be treated with one tablet every 24 hours. Primary endpoint: The effectiveness of nebivolol treatment in improving angina symptoms was measured using the SAQ questionnaire after 6 months of treatment. Secondary endpoints • Quality of life at 6 months. * Functional capacity at 6 months. * Major cardiac events at 1 year.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
150
Beta-blockers are the first-line treatment for patients with stable angina secondary to classic epicardial atherosclerotic disease, where their clinical benefits are well-established (4). However, their efficacy has not yet been demonstrated in ANOCA patients with MVD, where beta-blockers are frequently used due to their physiological plausibility. Beta-blockers act by competitively inhibiting catecholamine receptors. The therapeutic benefits of beta-blockade in patients with stable angina are mediated by a reduction in myocardial oxygen demand. Myocardial oxygen demand depends on heart rate, contractility, and left ventricular wall tension, all of which are reduced with beta-adrenergic blockade. The reduction in wall tension is partly mediated by the antihypertensive action of these drugs. The decrease in heart rate occurs both at rest and during sympathetic activation such as exercise or stress. The negative inotropic effect of these drugs also contributes to reducing myocardial oxyg
Placebo
SAQ questionnaire
The pre-specified primary outcome criterion is the improvement in angina severity assessed by the Seattle Angina Questionnaire (SAQ SS - Summary Score) at 6 months from the start of treatment compared to baseline. It will be evaluated by the mean difference in change within the same patient in SAQ between the two groups at 6 months of treatment. The SAQ is a validated self-administered scale that allows assessment of angina severity, frequency, quality of life, and functional limitation. It is the most commonly used and validated patient-reported outcome measure for angina. The SAQ provides a scale for evaluating the severity of angina that has been shown to be valid, reproducible, and sensitive to changes.
Time frame: 6 months
Quality of Life Status using the EuroQOL questionnaire (EQ5D-5L)
Patient's quality of life in both treatment groups will be assessed using the EuroQOL questionnaire (EQ5D-5L). The EQ5D-5L is the most widely used instrument for assessing health-related quality of life.
Time frame: 6 months
the Brief Illness Perception Questionnaire (B-IPQ)
Changes in disease perception will also be recorded using the Brief Illness Perception Questionnaire (B-IPQ)
Time frame: 6 months
anxiety and depression using PHQ-4
Quality of Life Status
Time frame: 6 months
The treatment satisfaction using the Treatment Satisfaction Questionnaire for Medication (TSQM-9)
Quality of Life Status
Time frame: 6 months
Functional Capacity
Functional capacity in both groups will be objectively assessed by performing a baseline and 6-month exercise treadmill test (ergometry) according to the Bruce protocol. The evaluated parameter will be the total duration of maximum exercise (seconds).
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Time frame: 6 months
Major Cardiac Events
The presence of major cardiac events will be adjudicated by an Independent Events Committee. Major cardiac events are defined as death from any cause, acute myocardial infarction, and hospitalization due to unstable angina, stroke, or heart failure requiring hospitalization.
Time frame: 6 months