Related Experiment Video
Updated: Jun 22, 2025
Interventional Diagnostic Procedure: A Practical Guide for the Assessment of Coronary Vascular Function
Published on: March 15, 2022
Protocol Variation in Functional Coronary Angiography Among Patients With Suspected Angina With Non-Obstructive
Jon Spiro1, Thomas J Ford2, Andy Yong3
1Department of Cardiology, Royal Perth Hospital, Perth, WA, Australia; University of Western Australia, Perth, WA, Australia.
Insights
Functional coronary angiography (FCA) protocols vary significantly across Australia and New Zealand, hindering diagnosis of coronary vasomotor disorders. Standardizing FCA can improve patient access and research collaboration.
Area of Science:
- Cardiology
- Diagnostic Imaging
- Clinical Research
Background:
- Functional coronary angiography (FCA) is recommended for angina patients with non-obstructive coronary arteries to characterize endotypes like vasospastic angina (VSA) and coronary microvascular disease (CMD).
- Existing diagnostic criteria for VSA and CMD lack a standardized FCA protocol, potentially limiting widespread adoption, result generalizability, and collaborative research.
- No prior data existed on FCA protocol variations across a major geographic region like Australia and New Zealand.
Purpose of the Study:
- To capture current practice variations in functional coronary angiography (FCA) protocols across Australia and New Zealand.
- To identify barriers to FCA program expansion and inform strategies for improved standardization.
- To enhance access and standardization for diagnosing coronary vasomotor disorders.
Main Methods:
- A national survey was conducted between July 2022 and July 2023.
- The survey targeted all centers in Australia and New Zealand with active FCA programs.
- 39 clinicians from 33 hospitals provided data on FCA attitudes and protocols.
Main Results:
- Significant variations in FCA protocols were observed, including testing techniques (Doppler vs. thermodilution), order of tests, acetylcholine administration, use of pacing wires, and vessel selection.
- Barriers to expanding FCA programs included cost, catheter laboratory time, and the lack of a national protocol.
- Despite perceived clinical utility, FCA was performed infrequently, with limited follow-on testing.
Conclusions:
- This survey reveals, for the first time, substantial variations in FCA protocols across Australia and New Zealand.
- FCA is considered clinically important, yet its utilization and follow-on testing remain infrequent.
- Developing and adopting a standardized national FCA protocol could improve patient access and facilitate collaborative research.
Background:
Functional coronary angiography (FCA) for endotype characterisation (vasospastic angina [VSA], coronary microvascular disease [CMD], or mixed) is recommended among patients with angina with non-obstructive coronary arteries. Whilst clear diagnostic criteria for VSA and CMD exist, there is no standardised FCA protocol. Variations in testing protocol may limit the widespread uptake of testing, generalisability of results, and expansion of collaborative research. At present, there are no data describing protocol variation across an entire geographic region. Therefore, we aimed to capture current practice variations in the approach to FCA to improve access and standardisation for diagnosis of coronary vasomotor disorders in Australia and New Zealand.
Method:
Between July 2022 and July 2023, we conducted a national survey across all centres in Australia and New Zealand with an active FCA program. The survey captured attitudes towards FCA and protocols used for diagnosis of coronary vasomotor disorders at 33 hospitals across Australia and New Zealand.
Results:
Survey responses were received from 39 clinicians from 33 centres, with representation from centres within all Australian states and territories and both North and South Islands of New Zealand. A total of 21 centres were identified as having an active FCA program. In general, respondents agreed that comprehensive physiology testing helped inform clinical management. Barriers to program expansion included cost, additional catheter laboratory time, and the absence of an agreed-upon national protocol. Across the clinical sites, there were significant variations in testing protocol, including the technique used (Doppler vs thermodilution), order of testing (hyperaemia resistance indices first vs vasomotor function testing first), rate and dose of acetylcholine administration, routine use of temporary pacing wire, and routine single vs multivessel testing. Overall, testing was performed relatively infrequently, with very little follow-on FCA performed, despite nearly all respondents believing this would be clinically useful.
Conclusions:
This survey demonstrates, for the first time, variations in FCA protocol among testing centres across two entire countries. Furthermore, whilst FCA was deemed clinically important, testing was performed relatively infrequently with little or no follow-on testing. Development and adoption of a standardised national FCA protocol may help improve patient access to testing and facilitate further collaborative research within Australia and New Zealand.
