Refining Diagnostic and Revascularisation Decisions and Outcomes Using Coronary Functional Assessments.

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Abstract in Hungarian

INTRODUCTION Percutaneous coronary intervention (PCI) for coronary revascularisation has made substantial progress, yielding increasingly favourable outcomes for high-risk patients, such as those with multivessel disease and notable comorbidities. Nevertheless, avoiding unnecessary interventions is critical, especially in stable coronary artery disease (sCAD) or chronic coronary syndromes (CCS). Precise lesion evaluation and verification of functional significance are vital for achieving optimal outcomes. Historically, coronary angiography has relied on visual assessment of coronary stenosis to decide the need for physiologic evaluation of a lesion’s functional significance. However, this approach is prone to interobserver and intraobserver variability, resulting in inconsistent determinations of lesion severity. While these challenges in lesion assessment are well-recognized within the context of CCS, they are further magnified in patients with advanced peripheral artery disease (PAD), particularly those presenting with critical limb ischemia (CLI). Peripheral artery disease is associated with heightened cardiovascular risk. Moreover, non-invasive diagnostic methods to detect coronary artery disease (CAD) often lack accuracy in CLI patients due to limitations in exercise testing, frequent balanced ischemia, and extensive coronary calcification. BACKGROUND Decisions about coronary revascularisation in CCS still rely heavily on angiographic visual assessment, despite known discordance with functional significance. This thesis evaluates how systematic coronary functional assessment can refine diagnosis, decisions, and outcomes. It comprises: (1) ABNORM, a prospective single-centre registry assessing operator decisions made without pressure-wire testing using retrospective quantitative flow ratio (QFR); and (2) INCORPORATE, a multicentre randomised trial in patients with critical limb ischaemia (CLI) comparing a default invasive strategy (angiography with fractional flow reserve (FFR)-guided revascularisation when indicated) versus conservative management after successful peripheral revascularisation. METHODS: Two studies were conducted. ABNORM prospectively enrolled consecutive CCS patients undergoing elective angiography when lesions were judged non-intermediate; management followed operator discretion. Blinded, post-hoc QFR (≤0.80) adjudicated appropriateness at vessel and patient levels. INCORPORATE randomised post-revascularisation CLI patients 1:1 to conservative therapy (OMT) or an invasive strategy (angiography with physiology-guided, reasonably complete revascularisation when indicated). Primary endpoint: all-cause death or spontaneous MI at 12 months; secondary: MACCE. RESULTS: ABNORM analysed 488 vessels: agreement between angiography-based decisions and QFR was 90% (21% appropriate revascularisations; 69% appropriate deferrals), with 10% misclassification (5% inappropriate revascularisation; 5% inappropriate deferral). Patient-level strategy was appropriate in 75%, with 13% incomplete revascularisation and 13% functional overtreatment. INCORPORATE enrolled 185 patients (96 conservative, 89 invasive). In the invasive arm, 81% had angiographic CAD and 60% functionally significant disease; 91% were discharged without residual functionally significant stenosis. The primary endpoint was neutral (11% vs 10%; HR 1.21, 95% CI 0.49–2.98). MACCE was numerically lower with the invasive strategy in PP/AT analyses; ITT showed a non-significant trend. CONCLUSION Both studies address diagnostic gaps in chronic coronary syndromes and critical limb ischaemia patients with suspected chronic coronary syndromes. First, persistent discordance between angiography and functional significance underscores integrating physiology in all angiograms, feasible via angiogram based functional assessments and artificial intelligence. Second, high rates of undiagnosed severe coronary artery disease in critical limb ischaemia remain unmasked pre-revascularisation due to limited mobility. An upfront invasive strategy with physiology-guided detection of functional relevance may reduce major adverse cardiac and cerebrovascular events, as per one-year trends, with greater long-term benefit.

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