Invasive evaluation of patients with angina in the absence of obstructive coronary artery disease

Area of Science:

• Cardiology
• Vascular Medicine
• Diagnostic Imaging

Background:

• Over 20% of patients with angina show no obstructive coronary artery disease on angiography.
• These patients frequently experience persistent symptoms, hospitalizations, and poor functional status without a clear diagnosis.
• This highlights a gap in understanding and diagnosing angina in the absence of significant coronary artery narrowing.

Purpose of the Study:

• To investigate the prevalence of occult coronary abnormalities in patients with angina and non-obstructive coronary artery disease (NOCAD).
• To assess the safety and diagnostic yield of a comprehensive invasive evaluation in this patient cohort.
• To identify potential causes for angina symptoms despite normal-appearing coronary arteries on angiography.

Main Methods:

• 139 patients with angina and NOCAD underwent assessment of endothelial function, index of microcirculatory resistance, coronary flow reserve, fractional flow reserve, and intravascular ultrasound.
• Intracoronary acetylcholine was used to assess endothelial function.
• Intravascular ultrasound evaluated for atherosclerosis, and myocardial bridging was identified.

Main Results:

• 61% of patients (44%) exhibited endothelial dysfunction, and 29% (21%) had microvascular impairment.
• Atherosclerosis was present in all patients on intravascular ultrasound.
• Myocardial bridging was identified in 58% of patients, and only 23% had no identifiable coronary explanation for their angina.

Conclusions:

• The majority of patients with angina and NOCAD possess occult coronary abnormalities.
• Comprehensive invasive assessment, including physiological measurements and imaging, is safe and diagnostically valuable.
• Identifying these hidden coronary issues can guide treatment and improve patient outcomes.