Coronary Microvascular Disease Management
Importance of Specialist Referral
- The American Heart Association and American College of Cardiology recommend referral to a specialist with expertise in coronary microvascular disease because invasive coronary function testing guided by specialists significantly improves angina severity and quality of life compared to conventional management, with demonstrated improvements of 11.7 units on the Seattle Angina Questionnaire 1, 2
- Specialist-guided invasive testing changes management in approximately 20% of patients and enables stratified medical therapy that directly targets the specific endotype of coronary microvascular dysfunction 1, 2, 3
Diagnostic Testing and Accurate Phenotyping
- Invasive coronary function testing is reasonable for patients with persistent stable chest pain and nonobstructive CAD with at least mild myocardial ischemia on imaging to improve diagnosis and enhance risk stratification, according to the American College of Cardiology 4
- Non-invasive advanced imaging with myocardial blood flow reserve measurement using PET or cardiac MRI is reasonable for diagnosing microvascular dysfunction and estimating risk of major adverse cardiovascular events, as recommended by the American Heart Association 4
- Specialists can distinguish between microvascular angina and vasospastic angina through acetylcholine testing, which is critical because beta-blockers are absolutely contraindicated in vasospastic angina, as stated by the European Society of Cardiology 8, 9, 3, 10
Evidence-Based Treatment
- The 2023 AHA/ACC guidelines give a Class 2a recommendation that stratified medical therapy guided by invasive coronary physiologic testing can be useful for improving angina severity and quality of life in symptomatic patients with nonobstructive CAD, with moderate strength of evidence 1, 8
- First-line therapy for confirmed microvascular dysfunction includes vasodilating beta-blockers, ACE inhibitors, statins, and aspirin to directly improve coronary flow reserve and repair endothelial function, as recommended by the American College of Cardiology 8, 9, 3, 10
Prognostic Implications and Specialist Follow-Up
- Nonobstructive CAD is present in >50% of patients undergoing elective coronary angiography and is associated with increased risk of all-cause death and myocardial infarction, according to the American Heart Association 8, 9, 3, 10
- Impaired coronary flow reserve (<2.32) among patients with nonobstructive CAD is associated with elevated hazard for major coronary events with 10-year follow-up, as reported by the European Society of Cardiology 4