5-Year Outcomes of PCI Guided by Measurement of Instantaneous Wave-Free Ratio Versus Fractional Flow Reserve

Advanced CT measures of coronary artery disease with intermediate stenosis in patients with severe aortic valve stenosis

BACKGROUND

Coronary artery disease (CAD) and severe aortic valve stenosis (AS) frequently coexist. While pre-transcatheter aortic valve replacement (TAVR) computed tomography angiography (CTA) allows to rule out obstructive CAD, interpreting hemodynamic significance of intermediate stenoses is challenging. This study investigates the incremental value of CT-derived fractional flow reserve (CT-FFR), quantitative coronary plaque characteristics (e.g., stenosis degree, plaque volume, and composition), and peri-coronary adipose tissue (PCAT) density to detect hemodynamically significant lesions among those with AS and CAD.

MATERIALS AND METHODS

We included patients with severe AS and intermediate coronary lesions (20-80% diameter stenosis) who underwent pre-TAVR CTA and invasive coronary angiogram (ICA) with resting full-cycle ratio (RFR) assessment between 08/16 and 04/22. CTA image analysis included assessment of CT-FFR, quantitative coronary plaque analysis, and PCAT density. Coronary lesions with RFR ≤ 0.89 indicated hemodynamic significance as reference standard.

RESULTS

Overall, 87 patients (age 77.9 ± 7.4 years, 38% female) with 95 intermediate coronary artery lesions were included. CT-FFR showed good discriminatory capacity (area under receiver operator curve (AUC) = 0.89, 95% confidence interval (CI) 0.81-0.96, p < 0.001) to identify hemodynamically significant lesions, superior to anatomical assessment, plaque morphology, and PCAT density. Plaque composition and PCAT density did not differ between lesions with and without hemodynamic significance. Univariable and multivariable analyses revealed CT-FFR as the only predictor for functionally significant lesions (odds ratio 1.28 (95% CI 1.17-1.43), p < 0.001). Overall, CT-FFR ≤ 0.80 showed diagnostic accuracy, sensitivity, and specificity of 88.4% (95%CI 80.2-94.1), 78.5% (95%CI 63.2-89.7), and 96.2% (95%CI 87.0-99.5), respectively.

CONCLUSION

CT-FFR was superior to CT anatomical, plaque morphology, and PCAT assessment to detect functionally significant stenoses in patients with severe AS.

CLINICAL RELEVANCE STATEMENT

CT-derived fractional flow reserve in patients with severe aortic valve stenosis may be a useful tool for non-invasive hemodynamic assessment of intermediate coronary lesions, while CT anatomical, plaque morphology, and peri-coronary adipose tissue assessment have no incremental or additional benefit. These findings might help to reduce pre-transcatheter aortic valve replacement invasive coronary angiogram.

KEY POINTS

• Interpreting the hemodynamic significance of intermediate coronary stenoses is challenging in pre-transcatheter aortic valve replacement CT. • CT-derived fractional flow reserve (CT-FFR) has a good discriminatory capacity in the identification of hemodynamically significant coronary lesions. • CT-derived anatomical, plaque morphology, and peri-coronary adipose tissue assessment did not improve the diagnostic capability of CT-FFR in the hemodynamic assessment of intermediate coronary stenoses.

Prognostic value of angiographic microvascular resistance in patients with ST-segment elevation myocardial infarction

BACKGROUND

The Angiographic Microvascular Resistance (AMR), derived from a solitary angiographic view, has emerged as a viable substitute for the Index of Microcirculatory Resistance (IMR). However, the prognostic significance in ST-Segment Elevation Myocardial Infarction (STEMI) patients is yet to be established. This research endeavors to explore the prognostic capabilities of AMR in patients diagnosed with STEMI.

METHODS

In this single-center, retrospective study, 232 patients diagnosed with STEMI who received primary Percutaneous Coronary Intervention (PCI) were recruited from January 1, 2018, to June 30, 2022. Utilizing the maximally selected log-rank statistics analysis, participants were divided into two cohorts according to an AMR threshold of 2.55 mmHg*s/cm. The endpoint evaluated was a composite of all-cause mortality or hospital readmission due to heart failure.

RESULTS

At a median follow-up of 1.74 (1.07, 3.65) years, the composite endpoint event was observed in 28 patients within the higher AMR group and 8 patients within the lower AMR group. The higher AMR group showed a significantly higher risk for composite outcome compared to those within the low-AMR group (HRadj: 3.33; 95% CI 1.30‒8.52; p = 0.03). AMR ≥ 2.55 mmHg*s/cm was an independent predictor of the composite endpoint (HR = 2.33; 95% CI 1.04‒5.21; p = 0.04). Furthermore, a nomogram containing age, sex, left ventricle ejection fraction, post-PCI Quantitative Flow Ratio (QFR), and AMR was developed and indicated a poorer prognosis in the high-risk group for STEMI patients at 3 years. (HR=4.60; 95% CI 1.91‒11.07; p < 0.01).

CONCLUSIONS

AMR measured after PCI can predict the risk of all-cause death or readmission for heart failure in patients with STEMI. AMR-involved nomograms improved predictive performance over variables alone.

Ischemia with non-obstructive coronary artery (INOCA): Non-invasive versus invasive techniques for diagnosis and the role of #FullPhysiology

Ischemia with non-obstructive coronary arteries (INOCA) is an increasingly recognized entity. It encompasses different pathophysiological subtypes (i.e., endotypes), including coronary microvascular dysfunction (CMD), vasospastic angina (VSA) and mixed entities resulting from the variable combination of both. Diagnosing INOCA and precisely characterizing the endotype allows for accurate medical treatment and has proven prognostic implications. A breadth of diagnostic technique is available, ranging from non-invasive approaches to invasive coronary angiography adjuvated by functional assessment and provocative tests. This review summarizes the strength and limitations of these methodologies and provides the rationale for the routine referral for invasive angiography and functional assessment in this subset of patients.

Assessment of Coronary Stenoses for Percutaneous Coronary Intervention: A Systematic Review and Network Meta-Analysis of Randomized Trials

Evidence regarding the comparative efficacy of the different methods to determine the significance of coronary stenoses in the catheterization laboratory is lacking. We aimed to compare all available methods guiding the decision to perform percutaneous coronary intervention (PCI). We searched Medline, Embase, and CENTRAL until October 5, 2023. We included trials that randomized patients with greater than 30% stenoses who were considered for PCI and reported major adverse cardiovascular events (MACE). We performed a frequentist random-effects network meta-analysis and assessed the certainty of evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. We included 15 trials with 16,333 participants with a mean weighted follow-up of 34 months. The trials contained a median of 49.3% (interquartile range: 32.6%, 100%) acute coronary syndrome participants. Quantitative flow ratio (QFR) was associated with a decreased risk of MACE compared with coronary angiography (CA) (risk ratio [RR] 0.68, 95% confidence interval [CI] 0.56 to 0.82, high certainty), fractional flow reserve (FFR) (RR 0.73, 95% CI 0.58 to 0.92, moderate certainty), and instantaneous wave-free ratio (iFR) (RR 0.63, 95% CI 0.49 to 0.82, moderate certainty), and ranked first for MACE (88.1% probability of being the best). FFR (RR 0.93, 95% CI 0.82 to 1.06, moderate certainty) and iFR (RR 1.07, 95% CI 0.90 to 1.28, moderate certainty) likely did not decrease the risk of MACE compared with CA. Intravascular imaging may not be associated with a significant decrease in MACE compared with CA (RR 0.85, 95% CI 0.62 to 1.17, low certainty) when used to guide the decision to perform PCI. In conclusion, a decision to perform PCI based on QFR was associated with a decreased risk of MACE compared with CA, FFR, and iFR in a mixed stable coronary disease and acute coronary syndrome population. These hypothesis-generating findings should be validated in large, randomized, head-to-head trials.

Advances in Clinical Cardiology 2023: A Summary of Key Clinical Trials

INTRODUCTION

Over the course of 2023, numerous key clinical trials with valuable contributions to clinical cardiology were published or presented at major international conferences. This review seeks to summarise these trials and reflect on their clinical context.

METHODS

The authors collated and reviewed clinical trials presented at major cardiology conferences during 2023 including the American College of Cardiology (ACC), European Association for Percutaneous Cardiovascular Interventions (EuroPCR), European Society of Cardiology (ESC), Transcatheter Cardiovascular Therapeutics (TCT), American Heart Association (AHA), European Heart Rhythm Association (EHRA), Society for Cardiovascular Angiography and Interventions (SCAI), TVT-The Heart Summit (TVT) and Cardiovascular Research Technologies (CRT). Trials with a broad relevance to the cardiology community and those with potential to change current practice were included.

RESULTS

A total of 80 key cardiology clinical trials were identified for inclusion. Key trials in acute coronary syndrome (ACS) and antiplatelet management such as HOST-IDEA, T-PASS and STOP-DAPT3 were included in addition to several pivotal interventional trials such as ORBITA 2, MULTISTARS-AMI, ILUMIEN-IV, OCTIVUS and OCTOBER. Additionally, several trials evaluated new stent design and technology such as BIOSTEMI, PARTHENOPE and TRANSFORM. Structural intervention trials included long-term data from PARTNER 3, new data on the durability of transcatheter aortic valve intervention (TAVI), in addition to major new trials regarding transcatheter tricuspid valve intervention from TRISCEND II. Heart failure (HF) and prevention covered several key studies including DAPA-MI, STEP-HF, ADVOR, DICTATE HF and CAMEO-DAPA. In cardiac devices and electrophysiology, several trial exploring novel ablation strategies in atrial fibrillation (AF) such as PULSED AF and ADVENT were presented with further data evaluating the efficacy of anticoagulation in subclinical AF in NOAH-AFNET 6, FRAIL AF and AZALEA-TIMI 71.

CONCLUSION

This article presents a summary of key clinical cardiology trials published and presented during the past year and should be of interest to both practising clinicians and researchers.

Complete Coronary Revascularization and Outcomes in Patients Who Underwent Coronary Artery Bypass Grafting: Insights from The REGROUP Trial

There is growing evidence in support of coronary complete revascularization (CR). Nonetheless, there is no universally accepted definition of CR in patients who undergo coronary bypass grafting surgery (CABG). We sought to investigate the outcomes of CR, defined as surgical revascularization of any territory supplied by a suitable coronary artery with ≥50% stenosis. We performed a preplanned subanalysis in the Randomized Trial of Endoscopic or Open Saphenous Vein Graft Harvesting (REGROUP) clinical trial cohort. Of 1,147 patients who underwent CABG, 810 (70.6%) received CR. The primary outcome was a composite of major adverse cardiac events (MACEs), including death from any cause, nonfatal myocardial infarction, or repeat revascularization over a median 4.7 years of follow-up. MACE occurred in 175 patients (21.6%) in the CR group and 86 patients (25.5%) in the incomplete revascularization (IR) group (hazard ratio [HR] 0.87, 95% confidence interval [CI] 0.67 to 1.13, p = 0.29). A total of 97 patients (12.0%) in the CR group and 48 patients (14.2%) in the IR group died (HR 0.93, 95% CI 0.65 to 1.32, p = 0.67); nonfatal myocardial infarction occurred in 49 patients (6.0%) in the CR group and 30 patients (8.9%) in the IR group (HR 0.76, 95% CI 0.48 to 1.2, p = 0.24), and repeat revascularization occurred in 62 patients (7.7%) in the CR group and 39 patients (11.6%) in the IR group (HR 0.64; 95% CI 0.42 to 0.95, p = 0.027). In conclusion, in patients with a great burden of co-morbidities who underwent CABG in the REGROUP trial over a median follow-up period of a median 4.7 years, CR was associated with similar MACE rates but a reduced risk of repeat revascularization. Longer-term follow-up is warranted.

Comparison among various physiology and angiography-guided strategies for deferring percutaneous coronary intervention: A network meta-analysis

BACKGROUND/PURPOSE

It is unclear whether coronary physiology or coronary angiography (CA)-guided strategy is the more preferable approach for deferring percutaneous coronary intervention (PCI). We sought to evaluate the clinical efficacy of various PCI strategies through a network meta-analysis of randomized controlled trials (RCTs).

METHODS/MATERIALS

We searched multiple databases for RCTs investigating the impact of the following strategies for the purpose of determining whether or not to defer PCI: fractional flow reserve, instantaneous wave-free ratio, quantitative flow ratio (QFR), and CA. We conducted a network meta-analysis for trial-defined major adverse cardiovascular events (MACE), all-cause death, cardiovascular death, myocardial infarction (MI), target lesion revascularization (TLR), and stent thrombosis. We performed a subgroup analysis for those with acute coronary syndrome (ACS).

RESULTS

Our search identified 12 eligible RCTs including a total of 13,177 patients. QFR-guided PCI was associated with reduced MACE, MI, and TLR compared with CA-guided PCI (relative risk (RR) 0.68; 95 % confidence interval (CI] [0.49 to 0.94], RR 0.58; 95 % CI [0.36 to 0.96], and RR 0.58; 95 % CI [0.38 to 0.91], respectively). There were no significant differences in any pairs for all-cause death, cardiovascular death, or stent thrombosis. QFR was ranked the best in most outcomes. In the subgroup analysis of the ACS cohort, there were no significant differences in MACE between any comparisons.

CONCLUSIONS

QFR was associated with reduced MACE, MI, and TLR compared with CA, and ranked the best in most outcomes. However, this was not applied in the ACS cohort.

Using Physiology Pullback for Percutaneous Coronary Intervention Guidance: Is this the Future?

Modern coronary intervention requires integration of angiographic, physiologic, and intravascular imaging. This article describes the use and techniques needed to understand coronary physiology pullback data and how use it to make revascularization decisions. The article describes instantaneous wave-free ratio, fractional flow reserve, and the data that support their use and how they differ when used in tandem disease. Common practical mistakes and errors are discussed together with a brief review of the limited published research data.

Hemodynamic Insights into Combined Fractional Flow Reserve and Instantaneous Wave-Free Ratio Assessment Through Quantitative [15O]H2O PET Myocardial Perfusion Imaging

In patients evaluated for obstructive coronary artery disease (CAD), guidelines recommend using either fractional flow reserve (FFR) or instantaneous wave-free ratio (iFR) to guide coronary revascularization decision-making. The hemodynamic significance of lesions with discordant FFR and iFR measurements is debated. This study compared [15O]H2O PET-derived absolute myocardial perfusion between vessels with concordant and discordant FFR and iFR measurements. Methods: We included 197 patients suspected of obstructive CAD who had undergone [15O]H2O PET perfusion imaging and combined FFR/iFR interrogation in 468 vessels. Resting myocardial blood flow (MBF), hyperemic MBF, and coronary flow reserve (CFR) were compared among 4 groups: FFR low/iFR low (n = 79), FFR high/iFR low (n = 22), FFR low/iFR high (n = 22), and FFR high/iFR high (n = 345). Predefined [15O]H2O PET thresholds for ischemia were 2.3 mL·min-1·g-1 or less for hyperemic MBF and 2.5 or less for CFR. Results: Hyperemic MBF was lower in the concordant low (2.09 ± 0.67 mL·min-1·g-1), FFR high/iFR low (2.41 ± 0.80 mL·min-1·g-1), and FFR low/iFR high (2.40 ± 0.69 mL·min-1·g-1) groups compared with the concordant high group (2.91 ± 0.84 mL·min-1·g-1) (P < 0.001, P = 0.004, and P < 0.001, respectively). A lower CFR was observed in the concordant low (2.37 ± 0.76) and FFR high/iFR low (2.64 ± 0.84) groups compared with the concordant high group (3.35 ± 1.07, P < 0.01 for both). However, for vessels with either low FFR or low iFR, quantitative hyperemic MBF and CFR values exceeded the ischemic threshold in 38% and 49%, respectively. In addition, resting MBF exhibited a negative correlation with iFR (P < 0.001) and was associated with FFR low/iFR high discordance compared with concordant low FFR/low iFR measurements, independent of clinical and angiographic characteristics, as well as hyperemic MBF (odds ratio [OR], 0.41; 95% CI, 0.26-0.65; P < 0.001). Conclusion: We found reduced myocardial perfusion in vessels with concordant low and discordant FFR/iFR measurements. However, FFR/iFR combinations often inaccurately classified vessels as either ischemic or nonischemic when compared with hyperemic MBF and CFR. Furthermore, a lower resting MBF was associated with a higher iFR and the occurrence of FFR low/iFR high discordance. Our study showed that although combined FFR/iFR assessment can be useful to estimate the hemodynamic significance of coronary lesions, these pressure-derived indices provide a limited approximation of [15O]H2O PET-derived quantitative myocardial perfusion as the physiologic standard of CAD severity.

Instantaneous wave free ratio vs. fractional flow reserve and 5-year mortality: iFR SWEDEHEART and DEFINE FLAIR

BACKGROUND AND AIMS

Guidelines recommend revascularization of intermediate epicardial artery stenosis to be guided by evidence of ischaemia. Fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) are equally recommended. Individual 5-year results of two major randomized trials comparing FFR with iFR-guided revascularization suggested increased all-cause mortality following iFR-guided revascularization. The aim of this study was a study-level meta-analysis of the 5-year outcome data in iFR-SWEDEHEART (NCT02166736) and DEFINE-FLAIR (NCT02053038).

METHODS

Composite of major adverse cardiovascular events (MACE) and its individual components [all-cause death, myocardial infarction (MI), and unplanned revascularisation] were analysed. Raw Kaplan-Meier estimates, numbers at risk, and number of events were extracted at 5-year follow-up and analysed using the ipdfc package (Stata version 18, StataCorp, College Station, TX, USA).

RESULTS

In total, iFR and FFR-guided revascularization was performed in 2254 and 2257 patients, respectively. Revascularization was more often deferred in the iFR group [n = 1128 (50.0%)] vs. the FFR group [n = 1021 (45.2%); P = .001]. In the iFR-guided group, the number of deaths, MACE, unplanned revascularization, and MI was 188 (8.3%), 484 (21.5%), 235 (10.4%), and 123 (5.5%) vs. 143 (6.3%), 420 (18.6%), 241 (10.7%), and 123 (5.4%) in the FFR group. Hazard ratio [95% confidence interval (CI)] estimates for MACE were 1.18 [1.04; 1.34], all-cause mortality 1.34 [1.08; 1.67], unplanned revascularization 0.99 [0.83; 1.19], and MI 1.02 [0.80; 1.32].

CONCLUSIONS

Five-year all-cause mortality and MACE rates were increased with revascularization guided by iFR compared to FFR. Rates of unplanned revascularization and MI were equal in the two groups.

Practical Application of Coronary Physiologic Assessment: Asia-Pacific Expert Consensus Document: Part 1

Coronary physiologic assessment is performed to measure coronary pressure, flow, and resistance or their surrogates to enable the selection of appropriate management strategy and its optimization for patients with coronary artery disease. The value of physiologic assessment is supported by a large body of evidence that has led to major recommendations in clinical practice guidelines. This expert consensus document aims to convey practical and balanced recommendations and future perspectives for coronary physiologic assessment for physicians and patients in the Asia-Pacific region based on updated information in the field that including both wire- and image-based physiologic assessment. This is Part 1 of the whole consensus document, which describes the general concept of coronary physiology, as well as practical information on the clinical application of physiologic indices and novel image-based physiologic assessment.

Prognostic impact of resting full-cycle ratio and diastolic non-hyperemic pressure ratios in patients with deferred revascularization

BACKGROUND

Non-hyperemic pressure ratios (NHPRs) like resting full-cycle ratio (RFR), diastolic pressure ratio during entire diastole (dPR[entire]) and diastolic pressure ratio during wave-free period (dPR[WFP]) are increasingly used to guide revascularization. The effect of NHPRs on mid-term prognosis has not been well established.

OBJECTIVE

We investigated the prognostic implications of NHRPs in patients whose revascularization was deferred based on fractional flow reserve (FFR) in a single-centre population.

METHODS

NHPRs and FFR were calculated offline from pressure tracings by an independent core laboratory. Follow-up data were acquired through records of hospital visits or telephone interviews. The primary outcome was a vessel-oriented composite outcome (VOCO) (a composite of cardiac death, vessel-related myocardial infarction, and ischemia-driven revascularization) in deferred vessels at 2 years.

RESULTS

316 patients with 377 deferred lesions were analysed. Discordance of NHPRs and FFR was found in 13.0-18.3% of lesions. The correlation coefficient between NHPRs was 0.99 (95% confidence interval 0.99-1.00). At 2 years, VOCO occurred in 19 lesions (5.0%). Estimated glomerular filtration rate < 30 mL/min/1.73 m2 [hazard ratio (HR) 5.7, p = 0.002], previous myocardial infarction (HR 3.3, p = 0.018), diabetes (HR 2.7, p = 0.042), RFR ≤ 0.89 (HR 2.7, p = 0.041) and dPR[WFP] ≤ 0.89 (HR 2.7, p = 0.049) were associated with higher incidence of VOCO at 2 years in the univariable analysis. A non-significant trend was found for dPR[entire] (HR 1.9, p = 0.26).

CONCLUSION

A positive RFR or dPR[WFP] were associated with a worse prognosis in deferred lesions, suggesting that the use of NHPRs in addition to FFR may improve risk estimation.

Applied coronary physiology for planning and guidance of percutaneous coronary interventions. A clinical consensus statement from the European Association of Percutaneous Cardiovascular Interventions (EAPCI) of the European Society of Cardiology

The clinical value of fractional flow reserve and non-hyperaemic pressure ratios are well established in determining an indication for percutaneous coronary intervention (PCI) in patients with coronary artery disease (CAD). In addition, over the last 5 years we have witnessed a shift towards the use of physiology to enhance procedural planning, assess post-PCI functional results, and guide PCI optimisation. In this regard, clinical studies have reported compelling data supporting the use of longitudinal vessel analysis, obtained with pressure guidewire pullbacks, to better understand how obstructive CAD contributes to myocardial ischaemia, to establish the likelihood of functionally successful PCI, to identify the presence and location of residual flow-limiting stenoses and to predict long-term outcomes. The introduction of new functional coronary angiography tools, which merge angiographic information with fluid dynamic equations to deliver information equivalent to intracoronary pressure measurements, are now available and potentially also applicable to these endeavours. Furthermore, the ability of longitudinal vessel analysis to predict the functional results of stenting has played an integral role in the evolving field of simulated PCI. Nevertheless, it is important to have an awareness of the value and challenges of physiology-guided PCI in specific clinical and anatomical contexts. The main aim of this European Association of Percutaneous Cardiovascular Interventions clinical consensus statement is to offer up-to-date evidence and expert opinion on the use of applied coronary physiology for procedural PCI planning, disease pattern recognition and post-PCI optimisation.

Midterm Clinical Outcomes for Deferred Coronary Revascularization on the Basis of Resting Full-Cycle Ratio and Fractional Flow Reserve Measurements

The midterm prognosis of patients with deferred revascularization based on resting full-cycle ratio (RFR) or fractional flow reserve (FFR) is not well established. We investigated the midterm clinical outcomes of 137 consecutive patients with deferred revascularization of 177 coronary arteries based on RFR and FFR. Patients were classified into 3 groups (concordant normal, concordant abnormal, discordant FFR and RFR), using known cutoffs for FFR (≤0.80) and RFR (≤0.89). All-cause mortality occurred in 9 (6.6%) and major adverse cardiac events (MACEs) in 16 patients (11.7%). Concordant abnormal, age, body mass index (BMI), and current or history of cancer were associated with increased risks of all-cause mortality. In a multivariable model, current or history of cancer was significantly associated with all-cause death (hazard ratio [HR] 6.8, p = 0.02). Concordant abnormal, current or history of cancer, BMI, and left ventricular ejection fraction were associated with increased risk of MACE, and all predictors correlated significantly with MACE (abnormal concordance: HR 4.2, p = 0.043; current or history of cancer: HR 4.0, p = 0.047; BMI: HR 0.8, p = 0.020; left ventricular ejection fraction: HR 0.9, p = 0.017). Although these results support performing percutaneous coronary intervention according to evidence-based RFR or FFR thresholds, deferred lesions with discordant FFR and RFR results were not associated with worse prognosis.

Comparison of vessel fractional flow reserve with invasive resting full-cycle ratio in patients with intermediate coronary lesions

BACKGROUND

Vessel fractional flow reserve (vFFR) is a novel angiography-derived index for the assessment of myocardial ischemia without the need for pressure wires and hyperemic agents. vFFR has demonstrated very good diagnostic performance compared with the hyperemic index fractional flow reserve (FFR). The aim of this study was to compare vFFR to the non-hyperemic pressure ratio resting full-cycle ratio (RFR).

METHODS

This was a retrospective, observational, single-center study of an all-comer cohort undergoing RFR assessment. Invasive coronary angiography was obtained without a dedicated vFFR acquisition protocol, and vFFR calculation was attempted in all vessels interrogated by RFR (1483 lesions of 1030 patients).

RESULTS

vFFR could be analyzed in 986 lesions from 705 patients. Median diameter stenosis was 37% (interquartile range (IQR): 30.0-44.0%), vFFR 0.86 (IQR: 0.81-0.91) and RFR 0.94 (IQR: (0.90-0.97). The correlation between vFFR and RFR was strong (r = 0.70, 95% confidence interval (CI): 0.66-0.74, p < 0.001). Using RFR ≤0.89 as reference, the sensitivity, specificity, positive predictive value, negative predictive value, and overall diagnostic accuracy for vFFR were 77%, 93%, 77%, and 92% and 89%. vFFR yielded a high area under the curve (AUC) of 0.92 (95% CI: 0.90-0.94). The good diagnostic performance of vFFR was confirmed among subgroups of patients with diabetes, severe aortic stenosis, female gender and lesions located in the left anterior descending artery.

CONCLUSION

vFFR has a high diagnostic performance taking RFR as the reference standard for evaluating the functional significance of coronary stenoses.

Revascularization and Medical Therapy for Chronic Coronary Syndromes: Lessons Learnt from Recent Trials, a Literature Review

Stable coronary artery disease (CAD) has recently been replaced by a new entity described as chronic coronary syndrome (CCS). This new entity has been developed based on a better understanding of the pathogenesis, the clinical characteristics, and the morbi-mortality associated to this condition as part of the dynamic spectrum of CAD. This has significant implications in the clinical management of CCS patients, that ranges from lifestyle adaptation, medical therapy targeting all the elements contributing to CAD progression (i.e., platelet aggregation, coagulation, dyslipidaemia, and systemic inflammation), to invasive strategies (i.e., revascularization). CCS is the most frequent presentation of coronary artery disease which is the first cardiovascular disease worldwide. Medical therapy is the first line therapy for these patients; however, revascularization and especially percutaneous coronary intervention remains beneficial for some of them. European and American guidelines on myocardial revascularization were released in 2018 and 2021, respectively. These guidelines provide different scenarios to help physicians choose the optimal therapy for CCS patients. Recently, several trials focusing on CCS patients have been published. We sought to synthetize the place of revascularization in CCS patients according to the latest guidelines, the lessons learnt from recent trials on revascularization and medical therapy, and future perspectives.

Coronary Physiology: Modern Concepts for the Guidance of Percutaneous Coronary Interventions and Medical Therapy

Recent evidence on ischemia, rather than coronary artery disease (CAD), representing a major determinant of outcomes, has led to a progressive shift in the management of patients with ischemic heart disease. According to most recent guidelines, myocardial revascularization strategies based on anatomical findings should be progressively abandoned in favor of functional criteria for the guidance of PCI. Thus, emerging importance has been assigned to the assessment of coronary physiology in order to determine the ischemic significance of coronary stenoses. However, despite several indexes and tools that have been developed so far, the existence of technical and clinical conditions potentially biasing the functional evaluation of the coronary tree still cause debates regarding the strategy of choice. The present review provides an overview of the available methods and the most recent acquirements for the invasive assessment of ischemia, focusing on the most widely available indexes, fractional flow reserve (FFR) and instant-wave free ratio (iFR), in addition to emerging examples, as new approaches to coronary flow reserve (CFR) and microvascular resistance, aiming at promoting the knowledge and application of those "full physiology" principles, which are generally advocated to allow a tailored treatment and the achievement of the largest prognostic benefits.

Percutaneous Coronary Intervention Versus Coronary Artery Bypass Grafting for Revascularization of Left Main Coronary Artery Disease

Owing to a large-jeopardized myocardium, left main coronary artery disease (LMCAD) represents the substantial high-risk anatomical subset of obstructive coronary artery disease. For several decades, coronary artery bypass grafting (CABG) has been the "gold standard" treatment for LMCAD. Along with advances in CABG, percutaneous coronary intervention (PCI) has also dramatically evolved over time in conjunction with advances in the stent or device technology, adjunct pharmacotherapy, accumulated experiences, and practice changes, establishing its position as a safe, reasonable treatment option for such a complex disease. Until recently, several randomized clinical trials, meta-analyses, and observational registries comparing PCI and CABG for LMCAD have shown comparable long-term survival with tradeoffs between early and late risk-benefit of each treatment. Despite this, there are still several unmet issues for revascularization strategy and management for LMCAD. This review article summarized updated knowledge on evolution and clinical evidence on the treatment of LMCAD, with a focus on the comparison of state-of-the-art PCI with CABG.

Editor-in-Chief's Top Picks From 2022

Each week, I record audio summaries for every paper in JACC, as well as an issue summary. This process has become a true labor of love due to the time they require, but I am motivated by the sheer number of listeners (16 million plus), and it has allowed me to familiarize myself with every paper that we publish. Thus, I have selected the top 100 papers (both Original Investigations and Review Articles) from distinct specialties each year. In addition to my personal choices, I have included papers that have been the most accessed or downloaded on our websites, as well as those selected by the JACC Editorial Board members. In order to present the full breadth of this important research in a consumable fashion, we will present these abstracts in this issue of JACC, as well as their Central Illustrations and podcasts. The highlights comprise the following sections: Basic & Translational Research, Cardiac Failure & Myocarditis, Cardiomyopathies & Genetics, Cardio-Oncology, Congenital Heart Disease, Coronary Disease & Interventions, Coronavirus, Hypertension, Imaging, Metabolic & Lipid Disorders, Neurovascular Disease & Dementia, Promoting Health & Prevention, Rhythm Disorders & Thromboembolism, and Valvular Heart Disease.^1-100.

Clinical Outcome of Revascularization Deferral With Instantaneous Wave-Free Ratio and Fractional Flow Reserve: A 5-Year Follow-Up Substudy From the iFR-SWEDEHEART Trial

Background Although physiology-based assessment of coronary artery stenosis using instantaneous wave-free ratio (iFR) and fractional flow reserve (FFR) are established methods of guiding coronary revascularization, its clinical outcome in long-term deferral needs further evaluation, especially with acute coronary syndrome as a clinical presentation. The aim was to evaluate the long-term clinical outcome of deferral of revascularization based on iFR or FFR. Methods and Results This is a substudy of the iFR-SWEDEHEART (Instantaneous Wave-Free Ratio Versus Fractional Flow Reserve in Patients With Stable Angina Pectoris or Acute Coronary Syndrome) randomized clinical trial, where patients deferred from revascularization from each study arm were selected. Nine hundred eight patients deferred from coronary revascularization with iFR (n=473) and FFR (n=435) were followed for 5 years. The national quality registry, SWEDEHEART (Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies), was used for patient data collection and clinical follow-up. The end point was major adverse cardiac events and their individual components all-cause death, cardiovascular death, noncardiovascular death, nonfatal myocardial infarction, and unplanned revascularization. No significant difference was found in major adverse cardiac events (iFR 18.6% versus FFR 16.8%; adjusted hazard ratio, 1.08 [95% CI, 0.79-1.48]; P=0.63) or their individual components. Conclusions No differences in clinical outcomes after 5-year follow-up were noted when comparing iFR versus FFR as methods for deferral of coronary revascularization in patients presenting with stable angina pectoris and acute coronary syndrome. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02166736.

Quantitative flow ratio-guided versus angiography-guided operation for valve disease accompanying coronary heart disease

Background

Valve replacement combined with coronary artery bypass graft (CABG) operation (VR + CABG) is usually associated with higher mortality and complication rates. Currently, angiography remains the most commonly used approach to guide CABG. The aim of this study is to investigate whether a quantitative flow ratio (QFR)-guided strategy can improve the clinical outcomes of VR + CABG.

Methods

Patients (n = 536) treated by VR + CABG between January 2018 and December 2021 were retrospectively assessed. In 116 patients, all lesions were revascularized entirely based on QFR (the QFR-guided group), whereas in 420 patients, all lesions were revascularized entirely based on angiography (the angiography-guided group). To minimize selection bias between the 2 groups, propensity score matching was performed at a ratio of 1:2. The primary endpoint of the study was the rate of major adverse cardiac and cerebrovascular events (MACCE) at 1-year, which was defined as a composite of cardiac mortality, myocardial infarction (MI), any repeat revascularization, and stroke.

Results

No statistically significant differences were observed in the baseline clinical characteristics between the QFR-guided and angiography-guided groups after propensity score matching. The mean age of all patients was 66.2 years [standard deviation (SD) = 8.3], 370 (69%) were men, the mean body-mass index of the population was 24.8 kg/m² (SD = 4.5), 129 (24%) had diabetes, and 229 (43%) had angina symptoms. When compared with the angiography-guided group, the QFR-guided group had a significantly shorter operative time (323 ± 60 min vs. 343 ± 71 min, P = 0.010), extra corporal circulation time (137 ± 38 min vs. 155 ± 62 min, P = 0.004), clamp time (73 ± 19 min vs. 81 ± 18 min, P < 0.001), and less intraoperative bleeding volume (640 ± 148 ml vs. 682 ± 166 ml, P = 0.022). Compared with the angiography-guided group, the 1-year MACCE was significantly lower in the QFR-guided group (6.9% vs. 14.7%, P = 0.036, hazard ratio = 0.455, 95% confidence interval: 0.211-0.982).

Conclusion

Our results raise the hypothesis that among patients who undergo VR + CABG, QFR-guided strategy is associated with optimized surgical procedure and a superior clinical outcome, as evidenced by a lower rate of MACCE at 1-year compared with conventional angiography-guided strategy.

Using Physiology Pullback for Percutaneous Coronary Intervention Guidance: Is this the Future?

Modern coronary intervention requires integration of angiographic, physiologic, and intravascular imaging. This article describes the use and techniques needed to understand coronary physiology pullback data and how use it to make revascularization decisions. The article describes instantaneous wave-free ratio, fractional flow reserve, and the data that support their use and how they differ when used in tandem disease. Common practical mistakes and errors are discussed together with a brief review of the limited published research data.

Is the world ready for the STICH 3.0 trial?

PURPOSE OF REVIEW

Coronary artery disease (CAD) is responsible for >50% of heart failures cases. Patients with ischemic left ventricular systolic dysfunction (iLVSD) are known to have poorer outcomes after percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) compared to patients with a normal ejection fraction. Nevertheless, <1% of patients in coronary revascularization trials to date had iLVSD. The purpose of this review is to describe coronary revascularization modalities in patients with iLVSD and highlight the need for randomized controlled trial evidence comparing these treatments in this patient population.

RECENT FINDINGS

Network meta-analytic findings of observational studies suggest that PCI is associated with higher rates of mortality, cardiac death, myocardial infarction, and repeat revascularization but not stroke compared to CABG in iLVSD. In recent years, outcomes for patients undergoing PCI have improved as a result of advances in technologies and techniques.

SUMMARY

The optimal coronary revascularization modality in patients with iLVSD remains unknown. In observational studies, CABG appears superior to PCI; however, direct randomized evidence is absent and developments in PCI techniques have improved post-PCI outcomes in recent years. The Surgical Treatment for Ischemic Heart Failure 3.0 consortium of trials will seek to address the clinical equipoise in coronary revascularization in patients with iLVSD.

Coronary physiology in the catheterisation laboratory: an A to Z practical guide

Coronary revascularisation, either percutaneous or surgical, aims to improve coronary flow and relieve myocardial ischaemia. The decision-making process in patients with coronary artery disease (CAD) remains largely based on invasive coronary angiography (ICA), even though until recently ICA could not assess the functional significance of coronary artery stenoses. Invasive wire-based approaches for physiological evaluations were developed to properly assess the ischaemic relevance of epicardial CAD. Fractional flow reserve (FFR) and later, instantaneous wave-free ratio (iFR), were shown to improve clinical outcomes in several patient subsets when used for coronary revascularisation guidance or deferral and for procedural optimisation of percutaneous coronary intervention (PCI) results. Despite accumulating evidence and positive guideline recommendations, the adoption of invasive physiology has remained quite low, mainly due to technical and economic issues as well as to operator-resistance to change. Coronary image-based computational physiology has been recently developed, with promising results in terms of accuracy and a reduction in computational time, costs, radiation exposure and risks for the patient. Lastly, the integration of intracoronary imaging and physiology allows for individualised PCI treatment, aiming at complete relief of ischaemia through optimised morpho-functional immediate procedural results. Instead of a conventional state-of-the-art review, this A to Z dictionary attempts to provide a practical guide for the application of coronary physiology in the catheterisation laboratory, exploring several methods, their pitfalls, and useful tips and tricks.

Left Main Coronary Artery Disease-Current Management and Future Perspectives

Due to its anatomical features, patients with an obstruction of the left main coronary artery (LMCA) have an increased risk of death. For years, coronary artery bypass grafting (CABG) has been considered as a gold standard for revascularization. However, notable advancements in the field of percutaneous coronary intervention (PCI) led to its acknowledgement as an important treatment alternative, especially in patients with low and intermediate anatomical complexity. Although recent years brought several random clinical trials that investigated the safety and efficacy of the percutaneous approach in LMCA, there are still uncertainties regarding optimal revascularization strategies. In this paper, we provide a comprehensive review of state-of-the-art diagnostic and treatment methods of LMCA disease, focusing on percutaneous methods.