Intravascular ultrasound-guided versus angiography-guided percutaneous coronary intervention in unprotected left main coronary artery disease: A systematic review

BACKGROUND

Significant unprotected left main coronary artery (ULMCA) disease is encountered in approximately 5 % of patients undergoing diagnostic coronary angiography. Intravascular ultrasound (IVUS) overcomes many of the known limitations of angiography and improves outcomes of patients undergoing percutaneous coronary interventions (PCI) in stable or complex coronary artery disease. The aim of this systematic review is to evaluate the evidence on IVUS-guidance versus angiography-guidance in ULMCA PCI, highlighting the chronological frequencies of event rates in line with the maturation of PCI technique and devices over time.

METHODS

A comprehensive systematic search in Medline was performed to identify all studies that had assessed the effect of IVUS-guided versus angiography-guided ULMCA PCI on various primary and secondary endpoints.

RESULTS

Seventeen studies (2 randomized, 10 non-randomized and 5 meta-analyses) were included in this systematic review.

CONCLUSIONS

This systematic review on IVUS-guided versus angiography-guided PCI in patients with significant ULMCA disease strongly supports the hypothesis that IVUS-guided PCI is associated with a significant reduction in major adverse cardiac events composites, all-cause death, cardiac death, myocardial infarction and stent thrombosis. Ongoing, adequately powered trials will contribute significantly to the level of evidence.

Optimal Minimal Stent Area and Impact of Stent Underexpansion in Left Main Up-Front 2-Stent Strategy

BACKGROUND

We previously reported the use of minimal stent area to predict angiographic in-stent restenosis after drug-eluting stent implantation for unprotected left main (LM) disease. We aimed to evaluate the optimal minimal stent area criteria for up-front LM 2-stenting based on long-term clinical outcomes.

METHODS

We identified 292 consecutive patients with LM bifurcation stenosis who were treated using the crush technique. The final minimal stent area was measured in the ostial left anterior descending artery (LAD), ostial left circumflex artery (LCX), and distal LM. The primary outcome was 5-year major adverse cardiac events, including all-cause death, myocardial infarction, and target lesion revascularization.

RESULTS

The minimal stent area cutoff values that best predicted the 5-year major adverse cardiac events were 11.8 mm2 for distal LM (area under the curve, 0.57; P=0.15), 8.3 mm2 for LAD ostium (area under the curve, 0.62; P=0.02), and 5.7 mm2 for LCX ostium (area under the curve, 0.64; P=0.01). Using these criteria, the risk of 5-year major adverse cardiac events was significantly associated with stent underexpansion in the LAD ostium (hazard ratio, 3.14; [95% CI, 1.23-8.06]; P=0.02) and LCX ostium (hazard ratio, 2.60 [95% CI, 1.11-6.07]; P=0.03) but not in the distal LM (hazard ratio, 0.81 [95% CI, 0.34-1.91]; P=0.63). Patients with stent underexpansion in both ostial LAD and LCX had a significantly higher rate of 5-year major adverse cardiac events than those with no or 1 underexpanded stent of either ostium (P<0.01).

CONCLUSIONS

Stent underexpansion in the LAD and LCX ostium was significantly associated with long-term outcomes in patients who underwent up-front 2-stenting for LM bifurcation stenosis.

Clinical Benefit of Intravascular Imaging Compared With Conventional Angiography in Left Main Coronary Artery Intervention

BACKGROUND

The RENOVATE-COMPLEX-PCI (Randomized Controlled Trial of Intravascular Imaging Guidance Versus Angiography-Guidance on Clinical Outcomes After Complex Percutaneous Coronary Intervention) demonstrated that intravascular imaging-guided percutaneous coronary intervention (PCI) improved clinical outcome compared with angiography-guided PCI for patients with complex coronary artery lesions. This study aims to assess whether the prognostic benefit of intravascular imaging-guided procedural optimization persists in patients undergoing PCI for left main coronary artery disease.

METHODS

Of 1639 patients enrolled in the RENOVATE-COMPLEX-PCI, 192 patients with left main coronary artery disease were selected for the current prespecified substudy. Selected patients were randomly assigned to either the intravascular imaging-guided PCI group (n=138) or the angiography-guided PCI group (n=54). The primary end point was target vessel failure defined as a composite of cardiac death, target vessel-related myocardial infarction, or clinically driven target vessel revascularization.

RESULTS

At a median follow-up of 2.1 years (interquartile range 1.1 to 3.0 years), intravascular imaging-guided PCI was associated with lower incidence of primary end point compared with angiography-guided PCI (6.8% versus 25.1%; hazard ratio, 0.31 [95% CI, 0.13-0.76]; P=0.010). This significant reduction in primary end point was mainly driven by a lower risk of cardiac death or spontaneous target vessel-related myocardial infarction (1.6% versus 12.7%; hazard ratio, 0.16 [95% CI, 0.03-0.82]; P=0.028). Intravascular imaging-guided PCI was independently associated with a lower risk of primary end point, even after adjusting for various clinical factors (hazard ratio, 0.29 [95% CI, 0.12-0.72]; P=0.007).

CONCLUSIONS

Intravascular imaging-guided PCI showed clinical benefit over angiography-guided PCI for left main coronary artery disease in reducing the risk of cardiac death, target vessel-related myocardial infarction, or target vessel revascularization.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03381872.

Intravascular Imaging During Percutaneous Coronary Intervention: JACC State-of-the-Art Review

Coronary angiography has historically served as the gold standard for diagnosis of coronary artery disease and guidance of percutaneous coronary intervention (PCI). Adjunctive use of contemporary intravascular imaging (IVI) technologies has emerged as a complement to conventional angiography-to further characterize plaque morphology and optimize the performance of PCI. IVI has utility for preintervention lesion and vessel assessment, periprocedural guidance of lesion preparation and stent deployment, and postintervention assessment of optimal endpoints and exclusion of complications. The role of IVI in reducing major adverse cardiac events in complex lesion subsets is emerging, and further studies evaluating broader use are underway or in development. This paper provides an overview of currently available IVI technologies, reviews data supporting their utilization for PCI guidance and optimization across a variety of lesion subsets, proposes best practices, and advocates for broader use of these technologies as a part of contemporary practice.

Intravascular imaging for left main stem assessment: An update on the most recent clinical data

Left main (LM) stem has different structural and anatomical characteristics compared to all of the other segments of the coronary tree, thus its management through percutaneous coronary intervention (PCI) is a challenge and is associated with worse clinical outcome and higher need for revascularization as compared to other lesion settings. Intravascular imaging, by means of intravascular ultrasound (IVUS) or optical coherence tomography (OCT), is an important tool for LM PCI guidance, aiming at improving the immediate performance and the long term outcome of this procedure. Following current guidelines and recent scientific findings, IVUS becomes important to firstly assess, and finally evaluate the result of LM stenting, according to the experience and preferences of the operator. The role of OCT still remains to be defined, but recent data is shedding light also on this imaging technique. The aim of this review is to highlight the latest scientific advancements regarding intravascular imaging in LM coronary artery disease.

Treatment of coronary bifurcation lesions, part I: implanting the first stent in the provisional pathway. The 16th expert consensus document of the European Bifurcation Club

Stepwise layered provisional stenting (PS) is the most commonly used strategy to treat coronary bifurcation lesions (CBL). The term 'stepwise layered' emphasises the versatility of this approach that allows the adjustment of the procedure plan according to the CBL complexity, starting with stent implantation in one branch and implantation of a second stent in the other branch only when required. A series of refinements have been implemented over the years to facilitate the achievement of predictable procedural results using this approach. However, despite its simplicity and versatility, operators using this technique require full knowledge of the pitfalls of each procedural step. Part I of this 16^th European Bifurcation Club consensus paper provides a detailed step-by-step overview of the pitfalls and technical troubleshooting during the implantation of the first stent using the PS strategy for the treatment of CBL.

A multi-center, international, randomized, 2-year, parallel-group study to assess the superiority of IVUS-guided PCI versus qualitative angio-guided PCI in unprotected left main coronary artery (ULMCA) disease: Study protocol for OPTIMAL trial

Background

Percutaneous coronary intervention (PCI) is used increasingly for revascularization of unprotected left main coronary artery (LMCA) disease. Observational studies and subgroup analyses from clinical trials, have suggested a possible benefit from the use of intravascular ultrasound (IVUS) guidance when performing unprotected LMCA PCI. However, the value of imaging with IVUS has never been proven in an appropriately powered randomized clinical trial. The OPtimizaTIon of Left MAin PCI With IntravascuLar Ultrasound (OPTIMAL) trial has been designed to establish whether IVUS-guided PCI optimization on LMCA is associated with superior clinical outcomes when compared with standard qualitative angiography-guided PCI.

Methods

The OPTIMAL trial is a randomized, multicenter, international study designed to enroll a total of 800 patients undergoing PCI for unprotected LMCA disease. Patients will be randomized in a 1:1 fashion to IVUS-guided PCI versus angiogram-guided PCI. In patients allocated to the angiogram-guided arm, use of IVUS is discouraged, unless there are safety concerns. In patients allocated to the IVUS guidance arm, pre-procedural IVUS assessment is highly recommended, whilst post-procedural IVUS assessment is mandatory to confirm appropriate stenting result and/or to guide stent result optimization, according to predefined criteria. Patients will be followed up to 2 years after the index procedure. The primary outcome measure is the Academic Research Consortium (ARC) patient-oriented composite endpoint (PoCE) which includes all-cause death, any stroke, any myocardial infarction and any repeat revascularization at 2 years follow-up.

Discussion

The OPTIMAL trial aims to provide definitive evidence about the clinical impact of IVUS-guidance during PCI to an unprotected LMCA. It is anticipated by the investigators, that an IVUS-guided strategy will be associated with less clinical events compared to a strategy guided by angiogram alone.

Trial registration

ClinicalTrials.gov: NCT04111770. Registered on October 1, 2019.

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.

Towards a common pathway for the treatment of left main disease: contemporary evidence and future directions: Left main disease treatment

There is increasing evidence to support percutaneous treatment of left main (LM) disease. Due to its major clinical impact, any procedure in the left main should be meticulously planned and performed. In this review, we aim to integrate the available evidence into a common treatment pathway, starting with understanding the distinct anatomical features of the left main. A three-level decision-making process is presented. First, in instances of angiographic ambiguity, intravascular ultrasound and fractional flow reserve can be used to decide if revascularisation could be deferred. Second, if revascularisation is indicated, the risks and benefits of percutaneous versus surgical procedures should be evaluated. Third, if percutaneous coronary intervention (PCI) is chosen, the operator should decide between the provisional single-stent versus upfront two-stent strategies. Regardless of the PCI technique selected, it should be performed according to the recommendations of a stepwise procedure utilising proximal optimisation (POT) after each instance of crossover stenting and kissing balloon inflation (KBI) where necessary. In addition to the recognised quality markers such as POT and KBI, we discuss the clinical relevance of the operator's LM PCI experience and the intracoronary imaging guidance when treating patients with left main disease.

Angiographic-only or intravascular ultrasound-guided approach for left-main coronary artery intervention: a systematic review and meta-analysis

INTRODUCTION

The use of intravascular ultrasound (IVUS) in percutaneous revascularization of left-main coronary artery disease (LMCAD) warrants further exploration. We aimed to collate all available data on the merits of IVUS in LMCAD to help decision-making.

METHODS

The MEDLINE, Embase, and Cochrane databases were queried for relevant randomized controlled trials (RCTs) and observational cohort studies (OCS). The data were analyzed using random-effects model to calculate unadjusted odds ratio (OR) between IVUS-guided and angiography-only LMCA revascularization.

RESULTS

A total of 14 studies (2 RCTs and 12 OCS), comprising 18944 patients, were included. The pooled odds of all-cause mortality (OR 0.57, 95%CI 0.46-0.70, p = <0.00001), cardiovascular mortality (OR 0.37, 95%CI 0.26-0.54, p = <0.00001), left-main revascularization (OR 0.63, 95%CI 0.45-0.89, p = 0.009) and myocardial infarction (OR 0.80, 95% CI 0.66-0.97, p = 0.02) were significantly lower with IVUS-guidance. There was no difference observed in the odds of the stent thrombosis (OR 0.57, 95% CI 0.31-1.05, p = 0.07) and stroke (OR 1.7, 95%CI 0.56-5.14, p = 0.35) between the two groups. A subgroup analysis based on the study design and follow-up duration mirrored the pooled estimates.

CONCLUSION

IVUS-guided LMCA intervention is associated with overall improved cardiovascular outcomes than the angiography-only approach. This needs to be tested in a large randomized controlled trial.

Optical coherence tomography, intravascular ultrasound or angiography guidance for distal left main coronary stenting. The ROCK cohort II study

OBJECTIVES

to test the safety and efficacy of intravascular imaging and specifically optical coherence tomography (OCT) as a diagnostic tool for left main angioplasty and analyze the mid-term outcome accordingly.

BACKGROUND

Clinical data and international guidelines recommend the use of intravascular imaging ultrasound (IVUS) to guide left main (LM) angioplasty. Despite early experience using OCT in this setting is encouraging, the evidence supporting its use is still limited.

METHODS

ROCK II is a multicenter, investigator-driven, retrospective European study to compare the performance of IVUS and OCT versus angiography in patients undergoing distal-LM stenting. The primary study endpoint was target-lesion failure (TLF) including cardiac death, target-vessel myocardial infarction and target-lesion revascularization. We designed this study hypothesizing the superiority of intravascular imaging over angiographic guidance alone, and the non-inferiority of OCT versus IVUS.

RESULTS

A total of 730 patients, 377 with intravascular-imaging guidance (162 OCT, 215 IVUS) and 353 with angiographic guidance, were analyzed. The one-year rate of TLF was 21.2% with angiography and 12.7% with intravascular-imaging (p = 0.039), with no difference between OCT and IVUS (p = 0.26). Intravascular-imaging was predictor of freedom from TLF (HR 0.46; 95% CI 0.23-0.93: p = 0.03). Propensity-score matching identified three groups of 100 patients each with no significant differences in baseline characteristics. The one-year rate of TLF was 16% in the angiographic, 7% in the OCT and 6% in the IVUS group, respectively (p = 0.03 for IVUS or OCT vs. angiography). No between-group significant differences in the rate of individual components of TLF were found.

CONCLUSIONS

Intravascular imaging was superior to angiography for distal LM stenting, with no difference between OCT and IVUS.

Online Co-Registration Of IVUS and OCT

Intravascular imaging using both intravascular ultrasound (IVUS) and optical coherence tomography (OCT) have become important tools in the Interventional Cardiologists armamentarium. However, in some centers, intravascular imaging is not widely employed. A number of reasons for this may exist, including lack of training in the use of intravascular imaging. Co-registration with angiography may be a helpful tool for those beginning to use both IVUS and OCT in the cath lab, and may reduce the learning curve associated with its use. For experienced operators, co-registration can shorten procedure time and lessen contrast use which may be particularly important when performing complex or multivessel PCI. As a research tool, co-registration can allow for accurate comparison of interval intravascular images. In this review, we will discuss how to acquire co-registered images using both IVUS and OCT systems, and the potential advantages of this technology over non-co-registered images, and indeed angiography alone.

Optical coherence tomography to guide percutaneous coronary intervention of the left main coronary artery: the LEMON study

BACKGROUND

Intravascular ultrasound (IVUS)-guided PCI improves the prognosis of left main stem (LMS) PCI and is currently recommended by international guidelines. Although OCT resolution is greater than that of IVUS, this tool is not yet recommended in LMS angioplasty due to the absence of data.

AIMS

This pilot study aimed to analyse the feasibility, safety and impact of OCT-guided LMS PCI.

METHODS

This prospective, multicentre trial investigated whether patients might benefit from OCT-guided PCI for mid/distal LMS according to a pre-specified protocol. The primary endpoint was procedural success defined as follows: residual angiographic stenosis <50% + TIMI 3 flow in all branches + adequate OCT stent expansion (LEMON criteria).

RESULTS

Seventy patients were included in the final analysis (median age: 72 [64-81] years, 73% male). The OCT pre-specified protocol was applied in all patients. The primary endpoint was achieved in 86% of subjects. Adequate stent expansion was observed in 86%, significant edge dissection in 30% and residual significant strut malapposition in 24% of the cases. OCT guidance modified the operators' strategy in 26% of the patients. The rate of one-year survival free from major adverse clinical events was 98.6% (97.2-100).

CONCLUSIONS

This pilot study is the first to report the feasibility and performance of OCT-guided LMS PCI according to a pre-specified protocol.

Intravascular ultrasound guidance in the evaluation and treatment of left main coronary artery disease

Percutaneous coronary intervention (PCI) of left main coronary artery (LMCA) disease has become an acceptable revascularization strategy. Evaluating the extent and characteristics of obstructive disease of the LMCA by angiography is challenging and limited in its accuracy. In contrast, intravascular ultrasound (IVUS) provides accurate imaging of the coronary lumen as well as quantitative measurements and quantitative assessment of the vessel wall components. IVUS for LMCA PCI should be performed before, during, and after intervention; IVUS enhances every step in the procedure and is associated with a mortality advantage in comparison with angiographic guidance alone. In this review, we provide an update on LMCA PCI and the role of IVUS for lesion assessment and stent optimization. In addition, the latest clinical evidence of the benefits of IVUS-guided LMCA PCI as compared to angiography is reviewed.