Complete coronary artery revascularization has become the Standard Of Care for patients presenting with STEMI and multivessel corner artery disease
Functional coronary angiography (FCA) refers to invasive assessment of coronary physiology—the dynamic, hemodynamic behavior of the coronary circulation—rather than the purely anatomical, intraluminal imaging provided by conventional (structural) angiography.
Functional coronary angiography (FFR) enables and assessment of coronary physiology directly from angiographic images, including both fractional flow reserve estimates and pull back analysis, without the need for pressure wires or hyperemic agents.
In patients with chronic coronary syndrome and intermediate lesions, this approach has been shown to be non-inferior to wire based FFR and superior to angiography guided decision-making.
FCA evaluates the coronary vessels’ dynamic response to provocative agents to diagnose vasomotor disorders that structural angiography cannot detect.
Because up to ~50–60% of patients undergoing elective angiography for angina have no obstructive disease (INOCA), FCA fills a critical diagnostic gap.
It uses a pressure/flow guidewire plus intracoronary vasoactive drugs to characterize both the macro- and microvasculature:
Epicardial (macrovascular) function — high-dose intracoronary acetylcholine provocation testing to diagnose epicardial coronary spasm (vasospastic angina); now demonstrated to be safe even in the MINOCA setting.
Microvascular function — coronary flow reserve (CFR) and index of microvascular resistance (IMR)/hyperemic microvascular resistance using adenosine (endothelium-independent), plus change in coronary flow with acetylcholine (endothelium-dependent).
Fractional flow reserve (FFR) to determine whether an indeterminate stenosis is functionally obstructive.
Roughly 80% of INOCA patients have an identifiable abnormality on FCA, and the landmark CorMicA trial showed that stratified medical therapy guided by FCA improves angina and quality of life.
Current guidelines support routine invasive functional assessment of both circulations in INOCA.
Functional angiography assessment of coronary physiology derived directly from the angiographic images—applying computational fluid dynamics/machine learning to yield virtual FFR (quantitative flow ratio, QFR) and pullback analysis without a pressure wire or hyperemic agent.
This provides an anatomic-and-functional assessment, particularly useful for borderline lesions, and has been extended to estimate microvascular resistance (angio-IMR).
In chronic coronary syndromes with intermediate lesions, this approach is noninferior to wire-based FFR and superior to angiography alone for guiding revascularization.
Visual angiographic stenosis severity correlates poorly with hemodynamic significance.
in the FAME study, a substantial proportion of angiographically significant multivessel disease was functionally nonsignificant by FFR (≤0.80 cutoff), and FFR-guided PCI reduced stent use and MACE.
Functional assessment (wire-based or angiography-derived) therefore refines lesion selection for PCI and, in the vasomotor sense, identifies treatable causes of angina in patients who would otherwise be falsely reassured.
In patients with STEMI and multi vessel coronary artery disease, a strategy of complete coronary artery revascularization, guided by functional coronary angiography resulted in a lower risk of primary outcome events of death, myocardial infarction, cerebral vascular accident, or ischemia driven revascularization than a strategy guided by conventional geography.