Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography & Interventions
October 18, 2026 · via Europe PMC
Additive Value of Acetylcholine Testing in ANOCA: A US-Based Multicenter FlowLab Study.
Ha ET, Shah SM, Toleva O, +8 more, Kobayashi Y.
AI summary — for doctors, generated from the abstract only
Adding acetylcholine vasospasm testing to ANOCA workup more than doubled diagnostic yield and led to endotype-directed medication changes.
What was studied
Prospective multicenter US study (FlowLab) of 253 catheterization procedures at 14 sites in patients with angina and non-obstructive coronaries, comparing sites that did versus did not perform spasm provocation testing alongside bolus thermodilution.
Key findings
- 155 procedures were at sites performing spasm testing and 98 at sites that did not
- Before catheterization, sites with spasm testing were less likely to suspect epicardial disease as the cause (27% vs 59.2%)
- Adding spasm provocation more than doubled diagnostic yield and was followed by medication changes matched to the diagnosed endotype
Clinical relevance
Without vasospasm provocation, a sizeable share of ANOCA endotypes may go undiagnosed, leaving patients on therapy that does not match their mechanism.
Who should care
Limitations
Non-randomized comparison across sites, so differences also reflect variation in procedural practice and patient selection rather than testing alone.
Consider including acetylcholine provocation in invasive ANOCA evaluation where available, so treatment can target the actual endotype.
This is an AI-generated summary of the published abstract, not a clinical recommendation. It may not reflect the full text or subsequent updates — verify against the original source before acting on it.
Abstract
Background
Angina with non-obstructive coronary arteries (ANOCA) is an underrecognized cause of angina with non-universal diagnostic techniques and patient management strategies. Among ANOCA testing, vasospasm provocation is not always performed mainly due to differences in institutional availability.
Aims
Using the FlowLab Study, we quantified vasospasm prevalence among patients with ANOCA at US centers and compared physician decision-making, endotype distribution, and management between sites that did and did not include vasospasm testing in their workup.
Methods
The FlowLab Study was a prospective, multicenter, US-based study of patients who were referred for coronary angiography and underwent ANOCA testing using the bolus thermodilution method. Presumed diagnosis before cardiac catheterization and final diagnosis after ANOCA testing were compared between participating sites with or without acetylcholine testing availability.
Results
A total of 253 procedures at 14 US sites were included in this study. There were 155 procedures among sites performing spasm provocation testing and 98 procedures among sites not performing spasm provocation testing. Prior to cardiac catheterization, sites with spasm provocation testing were less likely to suspect epicardial coronary artery disease as the cause of angina compared to sites without (27% vs. 59.2%, p < 0.0001). A diagnosis of CMD was made more frequently at sites performing spasm testing compared to sites not performing spasm testing (68% vs. 29.6%, p < 0.0001). Similarly, among 125 patients who underwent spasm provocation testing, diagnostic yield increased from 34.4% with bolus thermodilution alone to 84.8% after the addition of spasm provocation testing (p < 0.001). In these patients, intensification involving calcium channel blockers was more frequent with epicardial (67%) and microvascular spasm (41%) than without spasm (24%, p = 0.001).
Conclusions
In contemporary US practice, adding spasm provocation testing to bolus thermodilution more than doubled diagnostic yield and was followed by medication changes directed toward the diagnosed endotype. Differences between sites with and without spasm testing also reflected variation in procedural practice.
DOI
10.1002/ccd.70947
PMID
42894360
Research metadata (titles, abstracts, authors, publication dates) is sourced from Europe PMC, which aggregates content from PubMed/MEDLINE, PubMed Central, and other providers under the U.S. National Library of Medicine (NLM/NCBI). NLM does not claim copyright on abstracts; the original journal publishers or authors may hold rights to the full articles. AI-generated summaries are derived only from the abstract, never the full text, and are always labeled as AI-generated.
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