Efficacy of Targeted Medical Therapy in Angina and Nonobstructive Coronary Arteries

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