Coronary Physiology Guidance vs Conventional Angiography for Optimization of Percutaneous Coronary Intervention: The AQVA-II Trial

Functional coronary angiography to indicate and guide revascularization in STEMI patients with multivessel disease: Rationale and design of the AIR-STEMI trial

BACKGROUND

Complete revascularization has been shown to be superior to culprit-only treatment in patients with ST-segment elevation myocardial infarction (STEMI) and multivessel disease. However, it remains unclear whether complete revascularization should be guided by coronary physiology or conventional angiography. Angiography-derived physiology may allow functional assessment and procedural guidance using angiograms from primary percutaneous coronary intervention (PCI), potentially maximizing the benefits of a physiology-guided approach. We present the design of a dedicated study that will address this research gap.

METHODS AND DESIGN

The Functional Coronary Angiography to Indicate and Guide Revascularization in STEMI Patients with Multivessel Disease (AIR-STEMI) trial is a prospective, randomized, international, multicenter, open-label study with blinded adjudicated evaluation of outcomes. After successful treatment of the culprit lesion, patients will be randomized to receive PCI of the nonculprit lesions guided by conventional angiography or by angiography-derived fractional flow reserve (FFR). The primary endpoint is the composite endpoint of all-cause death, any myocardial infarction (MI), any cerebrovascular accident, or any revascularization. It will be censored once the last enrolled patient reaches 1-year follow-up. The secondary endpoint will be the composite of cardiovascular death or MI and each single component of the primary endpoint. All endpoints will be tested also at 3 and 5 years. The sample size for the study is a minimum of 1,800 patients.

IMPLICATIONS

The AIR-STEMI trial will provide novel evidence on whether a specific complete revascularization strategy should be applied to patients with STEMI and multivessel disease to improve their clinical outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05818475.

Prognostic Value of Postpercutaneous Coronary Intervention Murray-Law-Based Quantitative Flow Ratio: Post Hoc Analysis From FLAVOUR Trial

Background

Coronary physiology measured by fractional flow reserve (FFR) is superior to angiography for assessing the efficacy of percutaneous coronary intervention (PCI). Yet, the clinical adoption of post-PCI FFR is limited. Murray law-based quantitative flow ratio (μQFR) may represent a promising alternative, as it can quickly compute FFR from a single angiographic view.

Objectives

The authors aimed to investigate the potential role of post-PCI μQFR in predicting clinical outcomes.

Methods

This was a post hoc blinded analysis of the FLAVOUR trial. Patients with angiographically intermediate lesions randomized 1:1 to receive FFR or intravascular ultrasound-guided PCI were included. Post-PCI μQFR was assessed in successfully stented vessels, blinded to clinical outcomes. Suboptimal physiological outcome post-PCI was defined a priori as post-PCI μQFR <0.90. The primary endpoint was 2-year target vessel failure, including cardiac death, target vessel myocardial infarction, and target vessel revascularization. Secondary endpoints included the diagnostic concordance of pre-PCI μQFR with FFR in the FFR-guidance arm.

Results

Post-PCI μQFR was successfully analyzed in 806 vessels from 777 participants (feasibility 97.0% [806 of 831]). Suboptimal physiological outcome post-PCI was identified in 24.7% (199 of 806) of vessels and post-PCI μQFR <0.90 was associated with higher risk of 2-year target vessel failure (6.1% [12 of 199] vs 2.7% [16 of 607]; HR: 2.45 [95% CI: 1.14-5.26]; P = 0.022). Pre-PCI μQFR was obtained in 877 of 919 vessels (feasibility 95.4%), showing 90% accuracy, 82% sensitivity, and 94% specificity for identifying physiologically significant stenosis defined by pre-PCI FFR ≤0.80.

Conclusions

In patients with intermediate lesions who underwent PCI with contemporary imaging or physiology guidance, lower post-PCI μQFR values predict subsequent adverse events. (Fractional FLow Reserve And IVUS for Clinical OUtcomes in Patients With InteRmediate Stenosis [FLAVOUR]; NCT02673424).

Angiography-derived physiological patterns of coronary artery disease: implications with post-stenting physiology and long-term clinical outcomes

BACKGROUND

Physiological patterns of coronary artery disease (CAD) have emerged as potential determinants of functional results of percutaneous coronary interventions (PCI) and of vessel-oriented clinical outcomes (VOCE).

OBJECTIVES

In this study, we evaluated the impact of angiography-derived physiological patterns of CAD on post-PCI functional results and long-term clinical outcomes.

METHODS

Pre-PCI angiography-derived fractional flow reserve (FFR) virtual pullbacks were quantitatively interpreted and used to determine the physiological patterns of CAD. Suboptimal post-PCI physiology was defined as an angiography-derived FFR value ≤ 0.91. The primary endpoint was the occurrence of VOCE at the longest available follow-up.

RESULTS

Six hundred fifteen lesions from 516 patients were stratified into predominantly focal (n = 322, 52.3%) and predominantly diffuse (n = 293, 47.7%). Diffuse pattern of CAD was associated with lower post-PCI angiography-derived FFR values (0.91 ± 0.05 vs. 0.94 ± 0.05; p = 0.001) and larger rate of suboptimal post-PCI physiology (43.0 vs. 22.7%; p = 0.001), as compared to focal CAD. At the median follow-up time of 37 months (33-58), post-PCI suboptimal physiology was related to a higher risk of VOCE (16.2% vs. 7.6%; HR: 2.311; 95% CI 1.410-3.794; p = 0.0009), while no significant difference was noted according to baseline physiological pattern. In diffuse disease, the use of intracoronary imaging was associated with a lower incidence of long-term VOCE (5.1% vs 14.8%; HR: 0.313, 95% CI 0.167-0.614, p = 0.030).

CONCLUSIONS

Suboptimal post-PCI physiology is observed more often in diffusely diseased arteries and it is associated with higher risk of VOCE at follow-up. The use of intravascular imaging might improve clinical outcomes in the setting of diffuse CAD.

Coronary angiography: a review of the state of the art and the evolution of angiography in cardio therapeutics

Traditionally, coronary angiography was restricted to visual estimation of contrast-filled lumen in coronary obstructive diseases. Over the previous decades, considerable development has been made in quantitatively analyzing coronary angiography, significantly improving its accuracy and reproducibility.  Notably, the integration of artificial intelligence (AI) and machine learning into quantitative coronary angiography (QCA) holds promise for further enhancing diagnostic accuracy and predictive capabilities. In addition, non-invasive fractional flow reserve (FFR) indices, including computed tomography-FFR, have emerged as valuable tools, offering precise physiological assessment of coronary artery disease without the need for invasive procedures. These innovations allow for a more comprehensive evaluation of disease severity and aid in guiding revascularization decisions. This review traces the development of QCA technologies over the years, highlighting key milestones and current advancements. It also explores prospects that could revolutionize the field, such as AI integration and improved imaging techniques. By addressing both historical context and future directions, the article underscores the ongoing evolution of QCA and its critical role in the accurate assessment and management of coronary artery diseases. Through continuous innovation, QCA is poised to remain at the forefront of cardiovascular diagnostics, offering clinicians invaluable tools for improving patient care.

Role of physiology in the management of multivessel disease among patients with acute coronary syndrome

Multivessel coronary artery disease (CAD), defined as ≥50% stenosis in 2 or more epicardial arteries, is associated with a high burden of morbidity and mortality in acute coronary syndrome (ACS) patients. A salient challenge for managing this cohort is selecting the optimal revascularisation strategy, for which the use of coronary physiology has been increasingly recognised. Fractional flow reserve (FFR) is an invasive, pressure wire-based, physiological index measuring the functional significance of coronary lesions. Understanding this can help practitioners evaluate which lesions could induce myocardial ischaemia and, thus, decide which vessels require urgent revascularisation. Non-hyperaemic physiology-based indices, such as instantaneous wave-free ratio (iFR), provide valid alternatives to FFR. While FFR and iFR are recommended by international guidelines in stable CAD, there is ongoing discussion regarding the role of physiology in patients with ACS and multivessel disease (MVD); growing evidence supports FFR use in the latter. Compelling findings show FFR-guided complete percutaneous coronary intervention (PCI) can reduce adverse cardiovascular events, mortality, and repeat revascularisations in ACS and MVD patients compared to angiography-based PCI. However, FFR is limited in identifying non-flow-limiting vulnerable plaques, which can disadvantage high-risk patients. Here, integrating coronary physiology assessment with intracoronary imaging in decision-making can improve outcomes and quality of life. Further research into novel physiology-based tools in ACS and MVD is needed. This review aims to highlight the key evidence surrounding the role of FFR and other functional indices in guiding PCI strategy in ACS and MVD patients.

QFR for the Revascularization of Nonculprit Vessels in MI Patients: Insights From the FIRE Trial

BACKGROUND

The role of quantitative flow ratio (QFR) in the treatment of nonculprit vessels of patients with myocardial infarction (MI) is a topic of ongoing discussion.

OBJECTIVES

This study aimed to investigate the predictive capability of QFR for adverse events and its noninferiority compared to wire-based functional assessment in nonculprit vessels of MI patients.

METHODS

The FIRE (Functional Assessment in Elderly MI Patients With Multivessel Disease) trial randomized 1,445 older MI patients to culprit-only (n = 725) or physiology-guided complete revascularization (n = 720). In the culprit-only arm, angiographic projections of nonculprit vessels were prospectively collected, centrally reviewed for QFR computation, and associated with endpoints. In the complete revascularization arm, endpoints were compared between nonculprit vessels investigated with QFR or wire-based functional assessment. The primary endpoint was the vessel-oriented composite endpoint (VOCE) at 1 year.

RESULTS

QFR was measured on 903 nonculprit vessels from 685 patients in the culprit-only arm. Overall, 366 (40.5%) nonculprit vessels showed a QFR value ≤0.80, with a significantly higher incidence of VOCEs (22.1% vs 7.1%; P < 0.001). QFR ≤0.80 emerged as an independent predictor of VOCEs (HR: 2.79; 95% CI: 1.64-4.75). In the complete arm, QFR was used in 320 (35.2%) nonculprit vessels to guide revascularization. When compared with propensity-matched nonculprit vessels in which treatment was guided by wire-based functional assessment, no significant difference was observed (HR: 0.57; 95% CI: 0.28-1.15) in VOCEs.

CONCLUSIONS

This prespecified subanalysis of the FIRE trial provides evidence supporting the safety and efficacy of QFR-guided interventions for the treatment of nonculprit vessels in MI patients. (Functional Assessment in Elderly MI Patients With Multivessel Disease [FIRE]; NCT03772743).