Predictores de eventos cardiovasculares adversos mayores en la ecocardiografía intravascular tras el implante de stents liberadores de everolimus en lesiones coronarias largas

Impact of Stent Expansion Index on Stent Failure After Left Main Stenting

Impact of the stent expansion index (EXPI) in percutaneous coronary intervention (PCI) for unprotected left main distal bifurcation lesions (ULMD) has been not completely understood especially in current-generation drug-eluting stent (cDES) era. We evaluated the impact of EXPI on clinical outcomes after PCI with cDES for ULMD. We identified 342 patients treated with cDES for ULMD and postintervention intravascular ultrasound between January 2010 and December 2019. In this study, the ratio of minimum stent area (MSA) to reference vessel area at the MSA site was adopted to assess the stent expansion. We defined the patients with the first and second tertile as low-intermediate EXPI group and those with the third tertile as high EXPI group and compared the clinical outcomes between both groups. The primary end point was target lesion failure (TLF). TLF was defined as a composite of cardiac death, target lesion revascularization (TLR) ,and myocardial infarction. The MSA was located in the ostium of left anterior descending coronary artery in most cases (318 of 342 patients; 93.0%). There were no significant differences between both groups in the baseline clinical, lesion, and procedural characteristics. The high EXPI group had lower TLF rate than the low-intermediate EXPI group (10.2% vs 19.9%, log-rank p = 0.033). In conclusion, this is the first report that the higher ratio of MSA to reference vessel area at the MSA site, which was defined as stent EXPI, was associated with more favorable clinical outcomes after PCI for ULMD.

Accuracy of IVUS-Based Machine Learning Segmentation Assessment of Coronary Artery Dimensions and Balloon Sizing

Background

Accurate intravascular ultrasound (IVUS) measurements are important in IVUS-guided percutaneous coronary intervention optimization by choosing the appropriate device size and confirming stent expansion.

Objectives

The purpose of this study was to assess the accuracy of machine learning (ML) automatic segmentation of coronary artery vessel and lumen dimensions and balloon sizing.

Methods

Using expert analysis as the gold standard, ML segmentation of 60 MHz IVUS images was developed using 8,076 IVUS cross-sectional images from 234 patients, which were randomly split into training (83%) and validation (17%) data sets. The performance of ML segmentation was then evaluated using an independent test data set (437 images from 92 patients). The endpoints were the agreement rate between ML vs experts' measurements for appropriate balloon size selection, and lumen and acute stent areas. Appropriate balloon size was determined by rounding down from the mean vessel diameter or rounding up from the mean lumen diameter to the next balloon size. The difference of lumen area ≥0.5 mm2 was considered as clinically significant.

Results

ML model segmentation correlated well with experts' segmentation for training data set with a correlation coefficient of 0.992 and 0.993 for lumen and vessel areas, respectively. The agreement rate in lumen and acute stent areas was 85.5% and 97.0%, respectively. The agreement rate for appropriate balloon size selection was 70.6% by vessel diameter only and 92.4% by adding lumen diameter.

Conclusions

ML model IVUS segmentation measurements were well-correlated with those of experts and selected an appropriate balloon size in more than 90% of images.

Optical Coherence Tomography-Guided Percutaneous Coronary Intervention: Practical Application

Optical coherence tomography (OCT) provides high-resolution imaging of coronary arteries and can be used to optimize percutaneous coronary intervention (PCI). Intracoronary OCT, however, has had limited adoption in clinical practice. Novelty and relative complexity of OCT interpretation compared with the more established intravascular ultrasound, lack of a standardized algorithm for PCI guidance, paucity of data from randomized trials, and lack of rebate for intravascular imaging have contributed to the modest practical adoption of OCT. We provide a practical step-by-step guide on how to use OCT in PCI, including device set-up, simplified image interpretation, and an algorithmic approach for PCI. optimization.

Intravascular Ultrasound-Guided Percutaneous Coronary Intervention: Practical Application

Why is intravascular ultrasounography (IVUS) highly encouraged for the practical guidance of percutaneous coronary intervention (PCI)? First reason is to understand the mechanism of revascularization. Even if stenoses look similar in angiography, the pathophysiology could be different in each lesion. Second reason is to anticipate possible complications in advance. With prediction and appropriate preparation, most complications can be avoided or managed calmly when they occur. Third reason is to optimize PCI results with interactive IVUS use during the procedure. All these are essential to maximize the results of revascularization while minimizing acute complications, ultimately leading to improved long-term clinical outcomes.

Current clinical use of intravascular ultrasound imaging to guide percutaneous coronary interventions (update)

There are 3 main reasons to promote the practical application of IVUS during PCI. First reason is to understand the mechanism of vessel dilatation. Even if angiographic stenoses are similar, their pathophysiologies are different. It is important to understand what can happen by dilating coronary artery with balloon/stent, and to develop a strategy to achieve the maximum effect. Second reason is to anticipate possible complications and to reduce them in advance. In that case, we can deal with it as calmly as possible. Third reason is to validate the PCI performed. This should lead to further improvements of the procedures, which in turn will lead to improved short- and long-term prognosis. Then, high-quality PCI could be possible. This review summarizes the standard usage of IVUS in routine clinical practice and the use of IVUS in specific situations, especially complex lesions.

Rotational Atherectomy or Balloon-Based Techniques to Prepare Severely Calcified Coronary Lesions

BACKGROUND

The comparative efficacy of percutaneous techniques for the preparation of calcified lesions before stenting remains poorly studied.

OBJECTIVES

This study sought to compare the performance of up-front rotational atherectomy (RA) or balloon-based techniques before drug-eluting stent implantation in severely calcified coronary lesions as assessed by angiography and optical coherence tomography (OCT).

METHODS

Patient-level data from the PREPARE-CALC (Comparison of Strategies to Prepare Severely Calcified Coronary Lesions) and ISAR-CALC (Comparison of Strategies to Prepare Severely Calcified Coronary Lesions) randomized trials were pooled. The primary endpoint was stent expansion as assessed by OCT imaging. The secondary endpoints included stent eccentricity, stent asymmetry, angiographic acute lumen gain, strategy success and in-hospital occurrence of cardiac death, target vessel myocardial infarction, and repeat revascularization.

RESULTS

Among 274 patients originally randomized, 200 participants with available OCT data after lesion preparation with RA (n = 63), a modified balloon (MB, n = 103), or a super high-pressure balloon (n = 34) before stenting were analyzed. The use of RA versus MB or a super high-pressure balloon led to comparable stent expansion (73.2% ± 11.6% vs 70.8% ± 13.6% vs 71.8% ± 12.2%, P = 0.49) and stent asymmetry (P = 0.83). Compared with RA or MB, a super high-pressure balloon was associated with less stent eccentricity (P = 0.03) with a numerically higher acute lumen gain, albeit not significantly different (P = 0.08). Strategy success was more frequent with RA versus MB (P = 0.002) and numerically more frequent with RA versus a super high-pressure balloon (P = 0.06). Clinical outcomes did not differ between groups.

CONCLUSIONS

In patients with severely calcified lesions undergoing drug-eluting stent implantation, lesion preparation with RA, MB, or a super high-pressure balloon was associated with comparable stent expansion. A super high-pressure balloon is associated with less stent eccentricity, whereas strategy success is more frequent with RA.

Improving PCI Outcomes Using Postprocedural Physiology and Intravascular Imaging

Although clinical outcomes after percutaneous coronary intervention (PCI) are improving, the long-term risk for target vessel failure remains concerning. Although the application of intravascular imaging and physiological indexes significantly improves outcomes, their routine use in practice remains limited. Nevertheless, merely using these modalities is not enough, and to truly improve patient outcomes, optimal intravascular dimensions with minimal vascular injury should be targeted. When assessing post-PCI results using either type of physiological or imaging technology, a broad spectrum of stent- and vessel-related anomalies can be expected. As not all of these issues warrant treatment, a profound knowledge of what to expect and how to recognize and when to treat these intraluminal problems is needed. Additionally, promising new modalities such as angiography-derived coronary physiology and hybrid imaging catheters are becoming available. The authors provide an overview of the currently available tools and techniques to define suboptimal PCI and when to apply these technologies to improve outcomes.

Stent Expansion Indexes to Predict Clinical Outcomes: An IVUS Substudy From ADAPT-DES

OBJECTIVES

The aim of this study was to evaluate various stent expansion indexes to determine the best predictor of clinical outcomes.

BACKGROUND

Numerous intravascular ultrasound (IVUS) studies have shown minimum stent area (MSA) to be the most powerful predictor of future events.

METHODS

ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) was a prospective, multicenter registry of 8,582 patients undergoing percutaneous coronary intervention (PCI) with drug-eluting stents. Native coronary artery lesions treated with IVUS-guided PCI with final analyzable IVUS were included. Ten stent expansion indexes (MSA, MSA/vessel area at MSA site, conventional stent expansion [MSA/average of proximal and distal reference luminal area], minimum stent expansion using Huo-Kassab or linear model accounting for vessel tapering, stent asymmetry [minimum/maximum stent diameter within the entire stent], stent eccentricity [smallest minimum/maximum stent diameter at a single slice within the stent], IVUS-XPL [Impact of intravascular Ultrasound Guidance on Outcomes of Xience Prime Stents in Long Lesions] criteria, ULTIMATE [Intravascular Ultrasound Guided Drug Eluting Stents Implantation in "All-Comers" Coronary Lesions] criteria, and ILUMIEN IV criteria) were evaluated for their associations with lesion-specific 2-year clinically driven target lesion revascularization (TLR) or definite stent thrombosis.

RESULTS

Overall, 2,140 lesions in 1,831 patients were included; final MSA measured 6.2 ± 2.4 mm². Among the 10 stent expansion indexes, only MSA/vessel area at the MSA site was independently associated with 2-year clinically driven TLR or definite stent thrombosis (hazard ratio: 0.77; 95% confidence interval: 0.59-0.99; P = 0.04) after adjusting for morphologic and procedural parameters.

CONCLUSIONS

In this IVUS-guided PCI cohort with excellent final MSA overall, stent/vessel area at the MSA site, an index of relative stent expansion, was superior to absolute MSA and other expansion indexes in predicting 2-year clinically driven TLR or definite stent thrombosis.

Intracoronary optical coherence tomography: state of the art and future directions

Optical coherence tomography (OCT) has been increasingly utilised to guide percutaneous coronary intervention (PCI). Despite the diagnostic utility of OCT, facilitated by its high resolution, the impact of intracoronary OCT on clinical practice has thus far been limited. Difficulty in transitioning from intravascular ultrasound (IVUS), complex image interpretation, lack of a standardised algorithm for PCI guidance, and paucity of data from prospective clinical trials have contributed to the modest adoption. Herein, we provide a comprehensive up-do-date overview on the utility of OCT in coronary artery disease, including technical details, device set-up, simplified OCT image interpretation, recognition of the imaging artefacts, and an algorithmic approach for using OCT in PCI guidance. We discuss the utility of OCT in acute coronary syndromes, provide a summary of the clinical trial data, list the work in progress, and discuss the future directions.

Influences of different dose of tirofiban for acute ST elevation myocardial infarction patients underwent percutaneous coronary intervention

Tirofiban is widely used in patients with acute ST elevation myocardial infarction (STEMI) underwent percutaneous coronary intervention (PCI). This drug can efficiently improve myocardial perfusion and cardiac function, but its dose still remains controversial. We here investigated the effects of different dose of tirofiban on myocardial reperfusion and heart function in patients with STEMI. A total of 312 STEMI patients who underwent PCI in our hospital from March 2017 to March 2018 were enrolled and randomly divided into control group (75 cases, 0 μg/kg), low-dose group (79 cases, 5 μg/kg), medium-dose group (81 cases, 10 μg/kg) and high-dose group (77 cases, 20 μg/kg). The infarction-targeted artery flow grade evaluated by thrombolysis in myocardial infarction (TIMI), corrected TIMI frame count (CTFC) and sum-ST-segment resolution were recorded. At Day 7 and Day 30 after PCI, the left ventricular ejection fraction (LVEF), left ventricular end diastolic diameter, left ventricular end systolic diameter, major adverse cardiovascular events and the hemorrhage and thrombocytopenia were also evaluated. After PCI, the rate of TIMI grade 3, CTFC and incidence of sum-ST-segment resolution > 50% of high-dose group were significantly higher than those of control group, low-dose group and medium-dose group (P < .05), and the CTFC of medium -dose group were significantly higher than that of control group, low-dose group (P < .05). Moreover, the LVEF, left ventricular end diastolic diameter and left ventricular end systolic diameter of high-dose group were significantly improved than those of other groups, and the LVEF of medium-dose group was significantly superior to that of low-dose group (P < .05). However, the incidence of major adverse cardiac events in high-dose group was significantly decreased, while the hemorrhage and incidence of thrombocytopenia of high-dose group were significantly higher than those of other 3 groups (P < .05). The tirofiban can effectively alleviate the myocardial ischemia-reperfusion injury and promote the recovery of cardiac function in STEMI patients underwent PCI. Although the high-dose can enhance the clinical effects, it also increased the hemorrhagic risk. Therefore, the rational dosage application of tirofiban become much indispensable in view of patient's conditions and hemorrhagic risk, and a medium dose of 10 μg/kg may be appropriate for patients without high hemorrhagic risk.

Current clinical use of intravascular ultrasound imaging to guide percutaneous coronary interventions

During the past three decades, since the invention of intravascular ultrasound (IVUS), it has become increasingly important as daily clinical applications. However, it evolved with no Japanese standards for the measurement of images, the index of percutaneous coronary intervention (PCI) procedures, and the reporting of results. Accordingly, the purpose of this review article is to provide an optimal and consistent approach to IVUS usage during PCI for clinicians and investigators.

Comparison of Fractional FLow Reserve And Intravascular ultrasound-guided Intervention Strategy for Clinical OUtcomes in Patients with InteRmediate Stenosis (FLAVOUR): Rationale and design of a randomized clinical trial

BACKGROUND

Coronary angiography has limitations in defining the ischemia-causing stenotic lesion, especially in cases with intermediate coronary stenosis. Fractional flow reserve (FFR) is a current standard method to define the presence of ischemia, and intravascular ultrasound (IVUS) is the most commonly used invasive imaging tool that can provide the lesion geometry and can provide the information on plaque vulnerability. The primary aim of this study is to compare the safety and efficacy of FFR-guided and IVUS-guided percutaneous coronary intervention (PCI) strategies in patients with intermediate coronary stenosis.

TRIAL DESIGN

Comparison of Fractional FLow Reserve And Intravascular ultrasound-guided Intervention Strategy for Clinical OUtcomes in Patients with InteRmediate Stenosis (FLAVOUR) trial is an international, multicenter, prospective, randomized clinical trial. A total of 1,700 consecutive patients with intermediate stenosis (40%-70% by visual estimation) in a major epicardial coronary artery will be randomized 1:1 to receive either FFR-guided or IVUS-guided PCI strategy. Patients will be treated with PCI according to the predefined criteria for revascularization; FFR ≤ 0.80 in the FFR-guided group and Minimal Lumen Area (MLA) ≤3 mm² (or 3 mm²<MLA ≤4 mm² and plaque burden >70%) in the IVUS-guided group. The primary end point is the patient-oriented composite outcome, which is a composite of all-cause death, myocardial infarction, and any repeat revascularization at 24months after randomization. We will test noninferiority of current standard FFR-guided PCI strategy compared with IVUS-guided decision for PCI and stent optimization strategy.

CONCLUSION

The FLAVOUR trial will compare the safety and efficacy of FFR- and IVUS-guided PCI strategies in patients with intermediate coronary stenosis. This study will provide an insight on optimal evaluation and treatment strategy for patients with intermediate coronary stenosis.

IVUS Findings in Late and Very Late Stent Thrombosis. A Comparison Between Bare-metal and Drug-eluting Stents

INTRODUCTION AND OBJECTIVES

Stent thrombosis (ST) is a life-threatening complication after stent implantation. Intravascular ultrasound is able to discern most causes of ST. The aim of this study was to compare intravascular ultrasound findings between bare-metal stents (BMS) and drug-eluting stents (DES) in patients with late (31 days to 1 year) or very late ST (> 1 year).

METHODS

Of 250 consecutive patients with late or very late ST in 7 Spanish institutions, 114 patients (45.5% BMS and 54.5% DES) were imaged with intravascular ultrasound. Off-line intravascular ultrasound analysis was performed to assess malapposition, underexpansion, and neoatherosclerosis.

RESULTS

The median time from stent implantation to ST was 4.0 years with BMS and 3.4 years with DES (P = .04). Isolated malapposition was similarly observed in both groups (36.5% vs 46.8%; P = .18) but was numerically lower with BMS (26.6% vs 48.0%; P = .07) in patients with very late ST. Isolated underexpansion was similarly observed in both groups (13.5% vs 11.3%; P = .47). Isolated neoatherosclerosis occurred only in patients with very late ST and was more prevalent with BMS (22.9%) than with DES (6.0%); P = .02. At 2.9 years' follow-up, there were 0% and 6.9% cardiac deaths, respectively (P = .06) and recurrent ST occurred in 4.0% and 5.2% of patients, respectively (P = .60).

CONCLUSIONS

Malapposition was the most common finding in patients with late and very late ST and is more prevalent with DES in very late ST. In contrast, neoatherosclerosis was exclusively observed in patients with very late ST and mainly with BMS.