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Interventional Diagnostic Procedure: A Practical Guide for the Assessment of Coronary Vascular Function
Published on: March 15, 2022
Coronary Endothelial Dysfunction: Diagnostic Necessity or Futile Effort in Patients With Non-Obstructive Angina?
Johanna McChord1, Astrid Hubert1, Leonie Saccardi1
1Department of Cardiology and Angiology, Robert Bosch Hospital, Stuttgart, Germany.
Insights
Endothelial dysfunction (ED) is common in angina without obstructive coronary artery disease (ANOCA) but rarely isolated. Comprehensive coronary function testing should prioritize spasm and microvascular dysfunction over ED assessment.
Area of Science:
- Cardiology
- Vascular Biology
- Diagnostic Imaging
Background:
- Angina in the absence of obstructive coronary artery disease (ANOCA) is frequently associated with endothelial dysfunction (ED), coronary microvascular dysfunction (CMD), and coronary spasm.
- Endothelial dysfunction is characterized by a limited increase in coronary blood flow (<50%) or epicardial artery narrowing in response to low-dose acetylcholine (ACh).
- The prevalence and clinical significance of isolated ED are not well-established.
Purpose of the Study:
- To determine the prevalence of ED in ANOCA patients.
- To evaluate the diagnostic utility of ED assessment within comprehensive coronary function testing (CFT).
Main Methods:
- Eighty ANOCA patients underwent invasive coronary angiography with low- and high-dose ACh testing.
- Coronary blood flow (CBF) was measured, and quantitative coronary angiography (QCA) assessed coronary diameter.
- Coronary microvascular dysfunction (CMD) was defined by coronary flow reserve (CFR) < 2.5 and/or hyperemic microvascular resistance (HMR) > 2.5; coronary spasm was diagnosed per COVADIS criteria.
Main Results:
- Endothelial dysfunction (ED) was identified in 84% of patients; coronary spasm in 80%, and CMD in 45%.
- Combined spasm and CMD testing yielded a 90% diagnostic rate, reaching 100% with ED assessment.
- All patients without CMD or spasm exhibited ED, with only 10% having isolated ED. Notably, 27% of ED patients also had spasm at low-dose ACh.
Conclusions:
- Endothelial dysfunction (ED) is highly prevalent in ANOCA but seldom occurs in isolation.
- Given the significant effort for ED testing and its minimal addition to the diagnostic yield of CFT, prioritizing spasm and CMD assessment is recommended.
- Comprehensive spasm testing is crucial, as some ED patients present with spasm even at low acetylcholine doses.
Background:
Angina in the absence of stenosing coronary artery disease (ANOCA) is a common yet challenging condition often linked to endothelial dysfunction (ED), coronary microvascular dysfunction (CMD), and coronary spasm. ED is defined as a coronary blood flow (CBF) increase of < 50% or luminal narrowing of epicardial arteries in response to low-dose acetylcholine (ACh). The prevalence and clinical significance of isolated ED remain uncertain.
Aims:
This study aimed to determine the prevalence of ED in ANOCA patients and assess its diagnostic value in comprehensive coronary function testing (CFT).
Methods:
Eighty ANOCA patients underwent invasive coronary angiography with low- and high-dose ACh testing, CBF measurement, and quantitative coronary angiography (QCA)-based coronary diameter assessment. CMD was defined as coronary flow reserve (CFR) < 2.5 and/or hyperemic microvascular resistance (HMR) > 2.5. Coronary spasm was diagnosed using the Coronary Vasomotor Disorders International Study Group (COVADIS) criteria.
Results:
ED was present in 67 patients (84%), while coronary spasm and CMD were detected in 80% and 45%, respectively. Spasm provocation and CMD testing provided a 90% diagnostic yield, increasing to 100% with ED assessment. All ANOCA patients without CMD or spasm had ED. Only 10% had isolated ED. Additionally, 27% of ED patients showed spasm at low-dose ACh, highlighting the need for comprehensive spasm testing.
Conclusions:
ED is highly prevalent in ANOCA but rarely occurs in isolation. Since ED testing requires significant effort yet adds little to the overall diagnostic yield of CFT or the management of ANOCA patients, CFT should prioritize the assessment of spasm and CMD.
Trial Registration:
This study was not registered in a public clinical trials registry as it did not meet the criteria for mandatory registration, being a non-interventional, observational study focused on diagnostic evaluation.
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