Safety of intermediate left main stenosis revascularization deferral based on fractional flow reserve and intravascular ultrasound: A systematic review and meta-regression including 908 deferred left main stenosis from 12 studies

Contemporary State-of-the-Art PCI of Left Main Coronary Artery Disease

The left main coronary artery (LMCA) supplies over 70% of the myocardium, and significant LMCA disease is associated with high morbidity and mortality. With remarkable advances in percutaneous coronary intervention (PCI), including stent technology, antithrombotic agents, and evolving procedural techniques, PCI has become an important treatment option in clinical practice guidelines for the revascularization of LMCA disease. In contemporary clinical practice, a heart-team approach to shared decision-making, considering clinical/anatomic factors along with patient preferences, is emphasized for patients with significant LMCA disease requiring myocardial revascularization. Furthermore, recent progress in PCI procedures combined with intravascular imaging or functional guidance has resulted in significant improvements in PCI outcomes, especially for complex lesions, including LMCA disease. Nevertheless, owing to inherent anatomic complexities and frequent multivessel involvement, several unmet issues remain regarding the determination of the appropriate treatment approach for significant LMCA disease, for which further clinical research is required. This contemporary review article provides a comprehensive overview of left main PCI based on current guidelines and underlying trial data, addresses important unresolved diagnostic and therapeutic issues, and identifies future perspectives likely to advance progress in this field.

Diagnostic performance of intravascular ultrasound-based fractional flow reserve in evaluating of intermediate left main stenosis

BACKGROUND

The recently introduced ultrasonic flow ratio (UFR), is a novel fast computational method to derive fractional flow reserve (FFR) from intravascular ultrasound (IVUS) images. In the present study, we evaluate the diagnostic performance of UFR in patients with intermediate left main (LM) stenosis.

METHODS

This is a prospective, single center study enrolling consecutive patients with presence of intermediated LM lesions (diameter stenosis of 30%-80% by visual estimation) underwent IVUS and FFR measurement. An independent core laboratory assessed offline UFR and IVUS-derived minimal lumen area (MLA) in a blinded fashion.

RESULTS

Both UFR and FFR were successfully achieved in 41 LM patients (mean age, 62.0 ± 9.9 years, 46.3% diabetes). An acceptable correlation between UFR and FFR was identified (r = 0.688, P < 0.0001), with an absolute numerical difference of 0.03 (standard difference: 0.01). The area under the curve (AUC) in diagnosis of physiologically significant coronary stenosis for UFR was 0.94 (95% CI: 0.87-1.01), which was significantly higher than angiographic identified stenosis > 50% (AUC = 0.66, P < 0.001) and numerically higher than IVUS-derived MLA (AUC = 0.82; P = 0.09). Patient level diagnostic accuracy, sensitivity and specificity for UFR to identify FFR ≤ 0.80 was 82.9% (95% CI: 70.2-95.7), 93.1% (95% CI: 82.2-100.0), 58.3% (95% CI: 26.3-90.4), respectively.

CONCLUSION

In patients with intermediate LM diseases, UFR was proved to be associated with acceptable correlation and high accuracy with pressure wire-based FFR as standard reference. The present study supports the use of UFR for functional evaluation of intermediate LM stenosis.

Practical Application of Coronary Physiologic Assessment: Asia-Pacific Expert Consensus Document: Part 2

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 clinical data that has led to major recommendations in all 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 includes both wire- and image-based physiologic assessment. This is Part 2 of the whole consensus document, which provides theoretical and practical information on physiologic indexes for specific clinical conditions and patient statuses.

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.

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.

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.

Instantaneous Wave-Free Ratio for the Assessment of Intermediate Left Main Coronary Artery Stenosis: Correlations With Fractional Flow Reserve/Intravascular Ultrasound and Prognostic Implications: The iLITRO-EPIC07 Study

BACKGROUND

There is little information available on agreement between fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) in left main coronary artery (LMCA) intermediate stenosis. Besides, several meta-analyses support the use of FFR to guide LMCA revascularization, but limited information is available on iFR in this setting. Our aims were to establish the concordance between FFR and iFR in intermediate LMCA lesions, to evaluate with intravascular ultrasound (IVUS) in cases of FFR/iFR discordance, and to prospectively validate the safety of deferring revascularization based on a hybrid decision-making strategy combining iFR and IVUS.

METHODS

Prospective, observational, multicenter registry with 300 consecutive patients with intermediate LMCA stenosis who underwent FFR and iFR and, in case of discordance, IVUS and minimal lumen area measurements. Primary clinical end point was a composite of cardiovascular death, LMCA lesion-related nonfatal myocardial infarction, or unplanned LMCA revascularization.

RESULTS

FFR and iFR had an agreement of 80% (both positive in 67 and both negative in 167 patients); in case of disagreement (31 FFR+/iFR- and 29 FFR-/iFR+) minimal lumen area was ≥6 mm² in 8.7% of patients with FFR+ and 14.6% with iFR+. Among the 300 patients, 105 (35%) underwent revascularization and 181 (60%) were deferred according to iFR and IVUS. At a median follow-up of 20 months, major adverse cardiac events incidence was 8.3% in the defer group and 13.3% in the revascularization group (hazard ratio, 0.71 [95% CI 0.30-1.72]; P=0.45).

CONCLUSIONS

In patients with intermediate LMCA stenosis, a physiology-guided treatment decision is feasible either with FFR or iFR with moderate concordance between both indices. In case of disagreement, the use of IVUS may be useful to indicate revascularization. Deferral of revascularization based on iFR appears to be safe in terms of major adverse cardiac events.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT03767621.

The Contemporary Management of Left Main Coronary Artery Disease

The 'gold standard' in the management of left main coronary artery disease has historically been coronary artery bypass surgery. Recent innovations in drug-eluting stent technology coupled with the increasing utility of physiology and imaging guidance for procedures have led to an evolving role of percutaneous coronary intervention in left main disease of low and intermediate anatomical complexity. This revascularization modality carries the clear advantage of being less invasive and significantly reduced recovery times. This practice is currently supported by international guidelines, however, it remains a controversial topic in the field of interventional cardiology, and the long-term outcomes of a percutaneous strategy have been questioned. This review describes the current evidence base for the assessment and choice of intervention in left main coronary artery disease. The percutaneous revascularization techniques and use of imaging to optimize procedures and improve clinical outcomes have been discussed.

Quantitative flow ratio as a new tool for angiography-based physiological evaluation of coronary artery disease: a review

The functional evaluation of coronary stenoses has obtained important clinical results in recent years, resulting in strong guideline recommendations. Nonetheless, the use of coronary wire-based functional evaluation has not yet become part of the routine in catheterization laboratories for several reasons, including the need to advance a wire into the coronary vessel to interrogate the stenosis. Angiography-derived indexes have been introduced to expand the current use of physiology to estimate the functional meaning of a stenosis on the basis of angiographic data only. The most studied and validated angiography-derived index is certainly the quantitative flow ratio. This article will summarize the basics of the quantitative flow ratio, the related validation studies and its current and future applications.

Prediction of long-term patient outcome after contemporary left main stenting using the SYNTAX and SYNTAX II scores: A comparative analysis from the FAIL-II multicenter registry (failure in left main study with 2nd generation stents-Cardiogroup III study)

AIMS

To establish the value of the SYNTAX Score-II (SS-II) in predicting long-term mortality of patients treated with left main PCI (LM-PCI) using second-generation drug-eluting stents (DES).

METHODS AND RESULTS

The SYNTAX score (SS) and the SS-II were calculated in 804 patients included in the FAILS-2 registry (failure in left main study with 2nd generation stents). Patients were classified in low (SS-II ≤33; n = 278, 34.6%), intermediate (SS-II 34-43; n = 260, 32.3%) and high (SS-II ≥44; n = 266, 33.1%) SS-II tertiles. Primary endpoint was all-cause mortality. A significant difference in long-term mortality was noted (5.2 ± 3.6 years): 4.1, 7.5, and 16.7% in low, mid and high SS-II tertiles respectively (p < .001). SS-II score was more accurate in predicting mortality than SS (AUC = 0.73; 95%CI: 0.67-0.79 vs. AUC = 0.55; 95%CI: 0.48-0.63, respectively; p < .001). SS-II led to a reclassification in the risk of all-cause mortality re-allocating 73% of patients from the CABG-only indication to PCI or equipoise PCI-or-CABG indication. Using multiple Cox regression analysis, SS-II (HR: 1.07; 95%CI: 1.05-1.09; p < .001), along with Acute coronary syndrome (ACS) (HR: 1.66; 95%CI: 1.03-2.66; p = .07) and Cardiogenic shock (CS) (HR: 2.82 (95%CI: 1.41-5.64; p = .003) were independent predictors of long-term mortality. SS-II (HR: 1.05; 95%CI: 1.04-1.06; p < .001) along with Insulin dependent Type 2 DM (HR: 1.58, 95%CI: 1.09-2.30.; p < .05), ACS (HR: 1.58, 95%CI: 1.16-2.14; p < .001) and CS (HR: 2.02 95%CI 1.16-3.53; p < .05), were independent predictors of long-term MACE.

CONCLUSION

The SS-II was superior to the SS in predicting outcomes associated with contemporary LM-PCI. In this real-world population, two clinical variables not included in the SS-II, ACS and T2DM, were identified as additional markers of poor outcome.