Overview
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.
Eligibility
Inclusion Criteria:
- All patients with stable angina referred to the Stanford University Hospital cardiac catheterization laboratory for clinically indicated coronary function testing are eligible for inclusion into the study.
Specific inclusion criteria for randomization:
- Absence of significant epicardial coronary artery disease on angiography
- Fractional flow reserve > 0.80
And ≥ 1 of the following:
- Epicardial coronary spasm on acetylcholine testing
- Microvascular spasm on acetylcholine testing
- Coronary flow reserve < 2.5
- Index of microcirculatory resistance ≥ 25
- Myocardial bridge on intravascular ultrasound with dobutamine resting full-cycle ratio ≤ 0.76
Exclusion Criteria:
- Acute coronary syndrome less than one week prior to enrolment
- Cardiomyopathy
- Contraindications to beta-blockers or calcium channel blockers
- Baseline systolic blood pressure < 95 mmHg
- Baseline heart rate < 55 bpm