Predicting the response to acetylcholine in ischemia or infarction with non-obstructive coronary arteries: The ABCD...

Area of Science:

• Cardiology
• Diagnostic testing
• Vascular medicine

Background:

• Acetylcholine (ACh) provocation testing identifies vasomotor disorders in Ischemia and Non-Obstructed Coronary Arteries (INOCA) and Myocardial Infarction and Non-Obstructed Coronary Arteries (MINOCA) patients.
• Predicting a positive ACh test response is crucial for timely diagnosis and treatment.

Purpose of the Study:

• To derive and validate a simple risk score, the ABCD score, for predicting a positive ACh test response in INOCA and MINOCA patients.

Main Methods:

• Prospective enrollment of 551 INOCA and MINOCA patients undergoing ACh testing.
• Patients were divided into derivation (n=386) and validation (n=165) cohorts.
• The ABCD score was developed based on predictors: Myocardial Infarction and Non-Obstructed Coronary Arteries (MINOCA), myocardial bridge (MB), C-reactive protein (CRP), and dyslipidemia.

Main Results:

• The ACh test was positive in 52.3% of patients.
• Independent predictors for a positive ACh test included MINOCA, MB, elevated CRP, and dyslipidemia.
• The ABCD score demonstrated good predictive accuracy (AUC 0.703 in derivation, 0.705 in validation).
• An ABCD score ≥4 indicated a 94.3% risk of a positive ACh test; scores ≥6 were always positive.

Conclusions:

• The ABCD score can potentially obviate the need for ACh provocation testing in high-risk patients, thereby reducing procedural risks, time, and costs.
• Implementation of the ABCD score may facilitate tailored treatment strategies for INOCA and MINOCA.
• Further multicenter trials are recommended to validate and refine the ABCD score.