Clinical Impact of Suboptimal Stenting and Residual Intrastent Plaque/Thrombus Protrusion in Patients With Acute Coronary Syndrome

Intracoronary imaging guidance of percutaneous coronary interventions: how and when to apply validated metrics to improve the outcome

Percutaneous coronary intervention (PCI) is still burdened by a substantial number of complications despite constant technological advances, including the advent of intracoronary imaging (ICI) techniques. ICI modalities have been instrumental for the understanding the mechanism of PCI failure. Thanks to the ability to detail the pre-intervention coronary anatomy and identify the features indicative of sub-optimal stent deployment, ICI techniques can be utilised to improve coronary interventions in different clinical scenarios. More recently large randomized clinical trials on ICI guidance confirmed the clinical effectiveness of this approach especially in complex high-risk interventions.

Initial experience with a novel stent-based mechanical thrombectomy device for management of acute myocardial infarction cases with large thrombus burden

BACKGROUND

Patients with acute myocardial infarction (AMI) and large thrombus burden (LTB) still represent a challenge. Afflicted patients have a high morbidity and mortality. Aspiration thrombectomy is often ineffective in those cases. Mechanical thrombectomy devices (MTDs), which are effective for management of ischemic strokes, were recently CE-approved for treatment of thrombotic coronary lesions. Real-world data about their performance in AMI cases with LTB are scarce. This study sought to summarize our early experience with a novel MTD device in this context.

METHODS

We analyzed consecutive patients from the prospective OPTIMISER registry (NCT04988672), who have been managed with the NeVa™ MTD (Vesalio, USA) for AMI with LTB at a tertiary cardiology facility. Outcomes of interest included, among others, periprocedural complications, target lesion failure (TLF), target lesion revascularization (TLR) and target vessel myocardial infarction (TV-MI).

RESULTS

Overall, 15 patients underwent thrombectomy with the NeVa™ device. Thrombectomy was successfully performed in 14 (93%) patients. Final TIMI 3 flow was achieved in 13 (87%) patients, while 2 (13%) patients had TIMI 2 flow. We encountered no relevant periprocedural complications, especially no stroke, stent thrombosis or vessel closure. After a mean follow-up time of 26 ± 2.9 months, 1 (7%) patient presented with TLR due to stent thrombosis (10 months after treatment with the MTD and stenting).

CONCLUSIONS

In AMI patients with LTB, the deployment of the novel NeVa™ MTD seems efficient and safe. Further randomized trials are warranted to assess whether the use of the NeVa™ device in cases with LTB improves procedural and clinical outcomes.

Association between apolipoprotein B/A1 ratio and quantities of tissue prolapse on optical coherence tomography examination in patients with atherosclerotic cardiovascular disease

Atherosclerotic cardiovascular disease (ASCVD) continues to be a major health concern globally. Apolipoprotein (Apo) B/A1 ratio is a reliable predictor of ASCVD and an important factor in assessing the risk of myocardial infarction. Tissue prolapse (TP) is defined as the tissue extrusion into the lumen through the stent struts after implantation, which is a significant factor for poor short-term outcomes such as acute and subacute thrombosis, severe myocardial necrosis, and vulnerable plaque. Therefore, the aim of this study was to investigate the relationship between Apo B/A1, plaque vulnerability, and tissue prolapse on optical coherence tomography (OCT). This study enrolled 199 patients with atherosclerotic cardiovascular disease (ASCVD) who underwent percutaneous coronary intervention (PCI). Both pre- and post-procedural optical coherence tomography (OCT) examinations were conducted to assess TP volume and plaque morphology. Logistic regression analyses were performed to identify potential risk factors for tissue prolapse volume. Receiver operator characteristic (ROC) curve analysis was carried out to evaluate the value of the Apo B/A1 ratio for tissue prolapse volume. The high Apo B/A1 ratio group showed a larger TP volume (P = 0.001) and a higher percentage of plaque rupture and erosion in comparison to the low Apo B/A1 ratio group (P = 0.022 and P = 0.008). The high Apo B/A1 ratio group and the high TP volume group also had a higher proportion of thin-cap fibroatheroma (TCFA) (P = 0.046, P = 0.021). Multivariate logistic regression analysis revealed that both Apo B/A1 ratio (odds ratio [OR]: 1.041, 95% confidence interval [CI] 1.007-1.076; P = 0.019) and TCFA (OR: 3.199, 95%CI 1.133-9.031; 0.028) were significantly related to high TP volume. Furthermore, the area under the curve (AUC) for predictive value of TP volume was 0.635 for Apo B/A1 (95% CI 0.554-0.717, P = 0.002) compared to 0.615 for low density lipoprotein cholesterol (LDL-C) (95% CI 0.533-0.697, P = 0.008). The Apo B/A1 ratio is an independent predictor of TP volume on OCT and is related to plaque vulnerability.

Cardiac Optical Coherence Tomography: History, Current Status, and Perspective

For more than 2 decades since the first imaging procedure was performed in a living patient, intravascular optical coherence tomography (OCT), with its unprecedented image resolution, has made significant contributions to cardiovascular medicine in the realms of vascular biology research and percutaneous coronary intervention. OCT has contributed to a better understanding of vascular biology by providing insights into the pathobiology of atherosclerosis, including plaque phenotypes and the underlying mechanisms of acute coronary syndromes such as plaque erosion, neoatherosclerosis, stent thrombosis, and myocardial infarction with nonobstructive coronary arteries. Moreover, OCT has been used as an adjunctive imaging tool to angiography for the guidance of percutaneous coronary intervention procedures to optimize outcomes. However, broader application of OCT has faced challenges, including subjective interpretation of the images and insufficient clinical outcome data. Future developments including artificial intelligence-assisted interpretation, multimodality catheters, and micro-OCT, as well as large prospective outcome studies could broaden the impact of OCT on cardiovascular medicine.

Clinical impact of OCT-derived suboptimal stent implantation parameters and definitions

AIMS

Despite growing evidence supporting the clinical utility of optical coherence tomography (OCT) guidance during percutaneous coronary interventions (PCIs), there is no common agreement as to the optimal stent implantation parameters that enhance clinical outcome.

METHODS AND RESULTS

We retrospectively examined the predictive accuracy of suboptimal stent implantation definitions proposed from the CLI-OPCI II, ILUMIEN-IV OPTIMAL PCI, and FORZA studies for the long-term risk of device-oriented cardiovascular events (DoCE) in the population of large all-comers CLI-OPCI project. A total of 1020 patients undergoing OCT-guided drug-eluting stent implantation in the CLI-OPCI registry with a median follow-up of 809 (quartiles 414-1376) days constituted the study population. According to CLI-OPCI II, ILUMIEN-IV OPTIMAL PCI, and FORZA criteria, the incidence of suboptimal stent implantation was 31.8%, 58.1%, and 57.8%, respectively. By multivariable Cox analysis, suboptimal stent implantation criteria from the CLI-OPCI II [hazard ratio 2.75 (95% confidence interval 1.88-4.02), P < 0.001] and ILUMIEN-IV OPTIMAL PCI [1.79 (1.18-2.71), P = 0.006] studies, but not FORZA trial [1.11 (0.75-1.63), P = 0.597], were predictive of DoCE. At long-term follow-up, stent edge disease with minimum lumen area <4.5 mm2 [8.17 (5.32-12.53), P < 0.001], stent edge dissection [2.38 (1.33-4.27), P = 0.004], and minimum stent area <4.5 mm2 [1.68 (1.13-2.51), P = 0.011] were the main OCT predictors of DoCE.

CONCLUSION

The clinical utility of OCT-guided PCI might depend on the metrics adopted to define suboptimal stent implantation. Uncovered disease at the stent border, stent edge dissection, and minimum stent area <4.5 mm2 were the strongest OCT associates of stent failure.

Diagnosis and Prognostic Value of the Underlying Cause of Acute Coronary Syndrome in Optical Coherence Tomography-Guided Emergency Percutaneous Coronary Intervention

Background The prognostic impact of optical coherence tomography-diagnosed culprit lesion morphology in acute coronary syndrome (ACS) has not been systematically examined in real-world settings. Methods and Results This investigator-initiated, prospective, multicenter, observational study was conducted at 22 Japanese hospitals to identify the prevalence of underlying ACS causes (plaque rupture [PR], plaque erosion [PE], and calcified nodules [CN]) and their impact on clinical outcomes. Patients with ACS diagnosed within 24 hours of symptom onset undergoing emergency percutaneous coronary intervention were enrolled. Optical coherence tomography-guided percutaneous coronary intervention recipients were assessed for underlying ACS causes and followed up for major adverse cardiac events (cardiovascular death, myocardial infarction, heart failure, or ischemia-driven revascularization) at 1 year. Of 1702 patients with ACS, 702 (40.7%) underwent optical coherence tomography-guided percutaneous coronary intervention for analysis. PR, PE, and CN prevalence was 59.1%, 25.6%, and 4.0%, respectively. One-year major adverse cardiac events occurred most frequently in patients with CN (32.1%), followed by PR (12.4%) and PE (6.2%) (log-rank P<0.0001), primarily driven by increased cardiovascular death (CN, 25.0%; PR, 0.7%; PE, 1.1%; log-rank P<0.0001) and heart failure trend (CN, 7.1%; PR, 6.8%; PE, 2.2%; log-rank P<0.075). On multivariate Cox regression analysis, the underlying ACS cause was associated with 1-year major adverse cardiac events (CN [hazard ratio (HR), 4.49 [95% CI, 1.35-14.89], P=0.014]; PR (HR, 2.18 [95% CI, 1.05-4.53], P=0.036]; PE as reference). Conclusions Despite being the least common, CN was a clinically significant underlying ACS cause, associated with the highest future major adverse cardiac events risk, followed by PR and PE. Future studies should evaluate the possibility of ACS underlying cause-based optical coherence tomography-guided optimization.

Mitigating the risk of flow deterioration by deferring stent optimization in STEMI patients with large thrombus burden: Insights from a prospective cohort study

OBJECTIVES

It is uncertain, if omitting post-dilatation and stent oversizing (stent optimization) is safe and may decrease the risk for distal thrombus embolization (DTE) in STEMI patients with large thrombus burden (LTB).

BACKGROUND

In patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI) with stenting, (DTE) and flow deterioration are common and increase infarct size leading to worse outcomes.

METHODS

From a prospective registry, 74 consecutive STEMI patients with LTB undergoing pPCI with stenting and intentionally deferred stent optimization were analyzed. Imaging data and outcomes up to 2 years follow-up were analyzed.

RESULTS

Overall, 74 patients (18% females) underwent deferred stent optimization. Direct stenting was performed in 13 (18%) patients. No major complications occurred during pPCI. Staged stent optimization was performed after a median of 4 (interquartile range (IQR) 3; 7) days. On optical coherence tomography, under-expansion and residual thrombus were present in 59 (80%) and 27 (36%) cases, respectively. During deferred stent optimization, we encountered no case of flow deterioration (slow or no-reflow) or side branch occlusion. Minimal lumen area (mm2) and stent expansion (%) were corrected from 4.87±1.86mm to 6.82±2.36mm (p<0.05) and from 69±18% to 91±12% (p<0.001), respectively. During follow-up, 1 patient (1.4%) required target lesion revascularization and 1 (1.4%) patient succumbed from cardiovascular death.

CONCLUSIONS

Among STEMI patients with LTB, deferring stent optimization in the setting of pPCI appears safe and potentially mitigates the risk of DTE. The impact of this approach on infarct size and clinical outcomes warrants further investigation in a dedicated trial.

The Usefulness of Intracoronary Imaging in Patients with ST-Segment Elevation Myocardial Infarction

Intracoronary imaging (ICI) modalities, namely intravascular ultrasound (IVUS) and optical coherence tomography (OCT), have shown to be able to reduce major adverse cardiovascular events in patients undergoing percutaneous coronary intervention (PCI). Nevertheless, patients with ST-segment elevation myocardial infarction (STEMI) have been practically excluded from contemporary large randomized controlled trials. The available data are limited and derive mostly from observational studies. Nevertheless, contemporary studies are in favor of ICI utilization in patients who undergo primary PCI. Regarding technical aspects of PCI, ICI has been associated with the implantation of larger stent diameters, higher balloon inflations and lower residual in-stent stenosis post-PCI. OCT, although used significantly less often than IVUS, is a useful tool in the context of myocardial infarction without obstructive coronary artery disease since, due to its high spatial resolution, it can identify the underlying mechanism of STEMI, and, thus, guide therapy. Stent thrombosis (ST) is a rare, albeit a potential lethal, complication that is expressed clinically as STEMI in the vast majority of cases. Use of ICI is encouraged with current guidelines in order to discriminate the mechanism of ST among stent malapposition, underexpansion, uncovered stent struts, edge dissections, ruptured neoatherosclerotic lesions and coronary evaginations. Finally, ICI has been proposed as a tool to facilitate stent deferring during primary PCI based on culprit lesion characteristics.

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.

Optical Coherence Tomography-Guided Percutaneous Coronary Intervention: Evidence and Clinical Trials

Intracoronary imaging is beneficial to optimize stent implantation and reduce the risk of stent-related complications. Optical coherence tomography (OCT) is an intravascular imaging modality that allows for detailed microstructural evaluation during the percutaneous coronary intervention (PCI). Recently, several large-scale registries, randomized trials, and meta-analyses have shown the superiority of OCT to angiography and noninferiority to IVUS with respect to both acute procedural results and mid-term clinical outcomes. This article summarizes the data supporting the application of OCT-guided PCI to several specific situations, introduces important evidence, and discusses the ongoing controversies and limitations of the current evidence base in the field of OCT-guided PCI.

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.

Coronary bioresorbable stents: Non-invasive quantitative evaluation of intra- and juxta-stent plaque composition-A computed tomography longitudinal study

PURPOSE

Coronary bioresorbable stents (BRS) do not produce blooming artifacts on computed tomography (CT), in contrast to metallic stents, as they are made of a bioresorbable polymer and are radiolucent. They allow to evaluate the coronary plaque beneath. The low-attenuation plaque (LAP) suggests plaque vulnerability and is CT assessable. The aim of our study was to show the possibility of a non-invasive CT evaluation of the volume and the LAP composition of the intra- and juxta-stent plaque.

METHODOLOGY

In our prospective longitudinal study, we recruited 27 consecutive patients (35 BRS stents total; mean age 60 +/- 9 years) with bioresorbable stents for a 256-slice ECG-synchronized CT evaluation at 1- and 12-months post stent implantation. Total plaque volume (mm3), absolute and relative (%) LAP volume per block in the pre- intra- and post-stent zones were analyzed; comparison 1- and 12-months post-implantation of BRS. Changes in the previously mentioned variables were assessed by the mixed effects models with and without spline, which also accounted for the correlation between repeated measurements.

RESULTS

Our block or spline model analysis has shown no significant difference in plaque or absolute LAP volumes in pre- intra- and post-stent zones between 1 and 12 months. Interestingly, % LAP volume increases near-significantly in the distal block of the intrastent at 12-mo follow-up (from 23.38 ± 1.80% to 26.90 ± 2.22% (increase of 15%), p = 0.052).

CONCLUSION

Our study demonstrates the feasibility of the repeated non-invasive quantitative analysis of the intrastent coronary plaque and of the in-stent lumen by CT scan.

Optical coherence tomography in coronary atherosclerosis assessment and intervention

Since optical coherence tomography (OCT) was first performed in humans two decades ago, this imaging modality has been widely adopted in research on coronary atherosclerosis and adopted clinically for the optimization of percutaneous coronary intervention. In the past 10 years, substantial advances have been made in the understanding of in vivo vascular biology using OCT. Identification by OCT of culprit plaque pathology could potentially lead to a major shift in the management of patients with acute coronary syndromes. Detection by OCT of healed coronary plaque has been important in our understanding of the mechanisms involved in plaque destabilization and healing with the rapid progression of atherosclerosis. Accurate detection by OCT of sequelae from percutaneous coronary interventions that might be missed by angiography could improve clinical outcomes. In addition, OCT has become an essential diagnostic modality for myocardial infarction with non-obstructive coronary arteries. Insight into neoatherosclerosis from OCT could improve our understanding of the mechanisms of very late stent thrombosis. The appropriate use of OCT depends on accurate interpretation and understanding of the clinical significance of OCT findings. In this Review, we summarize the state of the art in cardiac OCT and facilitate the uniform use of this modality in coronary atherosclerosis. Contributions have been made by clinicians and investigators worldwide with extensive experience in OCT, with the aim that this document will serve as a standard reference for future research and clinical application.

Intravascular imaging in coronary stent restenosis: Prevention, characterization, and management

Despite the introduction of drug-eluting stents to combat the neointimal hyperplasia that occurred after BMS implantation, in-stent restenosis is still encountered in a significant number of patients, particularly as increasingly complex lesions are tackled by percutaneous coronary intervention. Many biological and mechanical factors interplay to produce restenosis, some of which are avoidable. Intravascular imaging provided unique insights into various forms of stent-related mechanical issues that contribute to this phenomenon. From a practical perspective, intravascular imaging can therefore help to optimize the stenting procedure to avert these issues. Moreover, once the problem of restenosis eventuates, imaging can guide the management by tackling the underlying identified mechanism. Finally, it can be used to evaluate the re-intervention results. Nevertheless, with the emergence of different treatment options, more evidence is needed to define patient/lesion-specific characteristics that may help to tailor treatment selection in a way that improves clinical outcomes.

Rationale and design of the TACTICS registry: Optical coherence tomography guided primary percutaneous coronary intervention for patients with acute coronary syndrome

BACKGROUND

Recent retrospective investigations have suggested that optical coherence tomography (OCT) enables the diagnosis of underlying acute coronary syndrome (ACS) causes such as plaque rupture, plaque erosion, and calcified nodule. The relationships of these etiologies with clinical outcomes, and the clinical utility of OCT-guided primary percutaneous coronary intervention (PCI) are not systematically studied in real-world ACS treatment settings.

METHODS

The TACTICS registry is an investigator-initiated, prospective, multicenter, observational study to be conducted at 21 hospitals in Japan. A total of 700 patients with ACS (symptom onset within 24 h) undergoing OCT-guided primary PCI will be enrolled. The primary endpoint of the study is to identify the underlying causes of ACS using OCT-defined morphological assessment of the culprit lesion. The key secondary clinical endpoints are hazard ratios of the composite of cardiovascular death, non-fatal myocardial infarction, heart failure, or ischemia-driven revascularization in patients with underlying etiologies at the 12- and 24-month follow-ups. The feasibility of OCT-guided primary PCI for ACS will be assessed by the achievement rates of optimal post-procedural results and safety endpoints.

CONCLUSION

The TACTICS registry will provide an overview of the underlying causes of ACS using OCT, and will reveal any difference in clinical outcomes depending on the underlying causes. The registry will also inform on the feasibility of OCT-guided primary PCI for patients with ACS.

Clinical outcomes of suboptimal stent deployment as assessed by optical coherence tomography: long-term results of the CLI-OPCI registry

BACKGROUND

Intraprocedural optical coherence tomography (OCT) is a valuable tool for guidance of percutaneous coronary intervention, but long-term follow-up data are lacking.

AIMS

The aim of this study was to address the long-term (7.5 years) clinical impact of quantitative OCT metrics of suboptimal stent implantation.

METHODS

This retrospective study includes 391 patients with long-term follow-up (mean 2,737 days; interquartile range 1,301-3,143 days) from the multicentre Centro per la Lotta contro l'Infarto - Optimisation of Percutaneous Coronary Intervention (CLI-OPCI) registry. OCT-assessed suboptimal stent deployment required the presence of at least one of the following pre-defined OCT findings: in-stent MLA <4.5 mm², proximal or distal reference lumen narrowing with lumen area <4.5 mm², significant proximal or distal edge dissection width ≥200 μm.

RESULTS

One hundred and two patients (26.1%) with 138 stented lesions (27.7%) experienced a device-oriented cardiovascular event (DOCE). In-stent MLA <4.5 mm² (38.1% vs 19.8%, p<0.001), in-stent lumen expansion <70% (29.5% vs 20.3%, p=0.032), proximal reference lumen narrowing <4.5 mm² (6.5% vs 1.4%, p=0.004), and distal reference lumen narrowing <4.5 mm² (12.9% vs 3.6%, p=0.001) were significantly more common in the DOCE vs non-DOCE group. OCT-assessed suboptimal stent deployment was an independent predictor of long-term DOCE (HR 2.17, p<0.001), together with bare metal stent implantation (HR 1.73, p=0.003) and prior revascularisation (HR 1.53, p=0.017).

CONCLUSIONS

The presence of OCT-assessed suboptimal criteria for stent implantation was related to a worse clinical outcome at very long-term follow-up. This information further supports an OCT-guided strategy of stent deployment.

Optical Coherence Tomography: An Eye Into the Coronary Artery

Optical coherence tomography (OCT) is slowly but surely gaining a foothold in the hands of interventional cardiologists. Intraluminal and transmural contents of the coronary arteries are no longer elusive to the cardiologist's probing eye. Although the graduation of an interventionalist in imaging techniques right from naked eye angiographies to ultrasound-based coronary sonographies to the modern light-based OCT has been slow, with the increasing regularity of complex coronary cases in practice, such a transition is inevitable. Although intravascular ultrasound (IVUS) due to its robust clinical data has been the preferred imaging modality in recent years, OCT provides a distinct upgrade over it in many imaging and procedural aspects. Better image resolution, accurate estimation of the calcified lesion, and better evaluation of acute and chronic stent failure are the distinct advantages of OCT over IVUS. Despite the obvious imaging advantages of OCT, its clinical impact remains subdued. However, upcoming newer trials and data have been encouraging for expanding the use of OCT to wider indications in clinical utility. During percutaneous coronary intervention (PCI), OCT provides the detailed information (dissection, tissue prolapse, thrombi, and incomplete stent apposition) required for optimal stent deployment, which is the key to successfully reducing the major adverse cardiovascular event (MACE) and stent-related morbidities. The increasing use of OCT in complex bifurcation stenting involving the left main (LM) is being studied. Also, the traditional pitfalls of OCT, such as additional contrast load for image acquisition and stenting involving the ostial and proximal LM, have also been overcome recently. In this review, we discuss the interpretation of OCT images and its clinical impact on the outcome of procedures along with current barriers to its use and newer paradigms in which OCT is starting to become a promising tool for the interventionalist and what can be expected for the immediate future in the imaging world.

CVIT expert consensus document on primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) update 2022

Primary Percutaneous Coronary Intervention (PCI) has significantly contributed to reducing the mortality of patients with ST-segment elevation myocardial infarction (STEMI) even in cardiogenic shock and is now the standard of care in most of Japanese institutions. The Task Force on Primary PCI of the Japanese Association of Cardiovascular Interventional and Therapeutics (CVIT) society proposed an expert consensus document for the management of acute myocardial infarction (AMI) focusing on procedural aspects of primary PCI in 2018. Updated guidelines for the management of AMI were published by the European Society of Cardiology (ESC) in 2017 and 2020. Major changes in the guidelines for STEMI patients included: (1) radial access and drug-eluting stents (DES) over bare-metal stents (BMS) were recommended as a Class I indication, (2) complete revascularization before hospital discharge (either immediate or staged) is now considered as Class IIa recommendation. In 2020, updated guidelines for Non-ST-Elevation Myocardial Infarction (NSTEMI) patients, the followings were changed: (1) an early invasive strategy within 24 h is recommended in patients with NSTEMI as a Class I indication, (2) complete revascularization in NSTEMI patients without cardiogenic shock is considered as Class IIa recommendation, and (3) in patients with atrial fibrillation following a short period of triple antithrombotic therapy, dual antithrombotic therapy (e.g., DOAC and single oral antiplatelet agent preferably clopidogrel) is recommended, with discontinuation of the antiplatelet agent after 6 to 12 months. Furthermore, an aspirin-free strategy after PCI has been investigated in several trials those have started to show the safety and efficacy. The Task Force on Primary PCI of the CVIT group has now proposed the updated expert consensus document for the management of AMI focusing on procedural aspects of primary PCI in 2022 version.

Plaque Prolapse after Stent Implantation in Ectasiant Coronary Artery Atherosclerotic Disease and Large Plaque Burden

Plaque prolapse (PP) is commonly defined as tissue extrusion through the stent strut. It is not a rare event, frequently detected by intravascular ultrasound, and it is associated with stent thrombosis and adverse outcomes. We present a case of PP after stenting of the left anterior descending coronary artery.

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.

Impact of stent edge dissection detected by optical coherence tomography after current-generation drug-eluting stent implantation

Background

Stent edge dissection (SED) is a well-known predictor of worse clinical outcomes. However, impact of SED after current-generation drug-eluting stent (DES) implantation remains unknown since there was no study using only current-generation DES to assess impact of SED. This study aimed to investigate a relationship between SED detected by optical coherence tomography (OCT) and clinical outcomes after current-generation DES implantation.

Methods

This study enrolled 175 patients receiving OCT after current-generation DES implantation. The SED group was compared with the non-SED group in terms of the primary study endpoints which was the cumulative incidence of major adverse cardiac event (MACE) composed of cardiac death, target vessel myocardial infarction (TV-MI), and clinically-driven target lesion revascularization (CD-TLR).

Results

Of 175 patients, SED detected by OCT was observed in 32 patients, while 143 patients did not show SED. In the crude population, the SED group showed a significantly higher incidence of CD-TLR, definite stent thrombosis, TV-MI and cardiac death relative to the non-SED group. After adjustment by an inverse probability weighted methods, the SED group showed a significantly higher incidence of MACE compared with the non-SED group (hazard ratio 3.43, 95% confidence interval 1.09–10.81, p = 0.035). Fibrocalcific or lipidic plaques, greater lumen eccentricity, and stent-oversizing were the predictors of SED.

Conclusions

SED detected by OCT after the current-generation DES implantation led to unfavorable outcomes. Aggressive post-dilatation around the stent edge might worse clinical outcomes due to SED, although achievement of optimal stent expansion is strongly encouraged to improve clinical outcomes.

Risk Stratification of Patients with Acute Coronary Syndrome

Defining the risk factors affecting the prognosis of patients with acute coronary syndrome (ACS) has been a challenge. Many individual biomarkers and risk scores that predict outcomes during different periods following ACS have been proposed. This review evaluates known outcome predictors supported by clinical data in light of the development of new treatment strategies for ACS patients during the last three decades.

Impact of Optical Coherence Tomography Imaging on Decision-Making During Percutaneous Coronary Intervention in Patients Presented With Acute Coronary Syndromes

BACKGROUND

Optical coherence tomography (OCT) provides valuable information to guide percutaneous coronary intervention (PCI) in acute coronary syndrome (ACS) regarding lesion preparation, stent sizing, and optimization. The aim of the present study was to compare lumen expansion of stent-treated lesions immediately after the procedure for ACS between OCT-guided PCI and angiography-guided PCI.Methods and Results:This study investigated stent-treated lesions immediately after PCI for ACS by using quantitative coronary angiography in 390 patients; 260 patients with OCT-guided PCI and 130 patients with angiography-guided PCI. Before stenting, the frequency of pre-dilatation and thrombus aspiration were not different between the OCT-guided and angiography-guided PCI groups. Stent diameter was significantly larger as a result of OCT-guided PCI (3.11±0.44 mm vs. 2.99±0.45 mm, P=0.011). In post-dilatation, balloon pressure-up (48% vs. 31%, P=0.001) and balloon diameter-up (33% vs. 6%, P<0.001) were more frequently performed in the OCT-guided PCI group. Minimum lumen diameter (2.55±0.35 mm vs. 2.13±0.50 mm, P<0.001) and acute lumen gain (2.18±0.54 mm vs. 1.72±0.63 mm, P<0.001) were significantly larger in the OCT-guided PCI group. Percent diameter stenosis (14±4% vs. 24±10%, P<0.001) and percent area stenosis (15±5% vs. 35±17%, P<0.001) were significantly smaller in the OCT-guided PCI group.

CONCLUSIONS

OCT-guided PCI potentially results in larger lumen expansion of stent-treated lesions immediately after PCI in the treatment of ACS compared with angiography-guided PCI.

Optical Coherence Tomography in Acute Coronary Syndromes

Advances in intravascular imaging have enabled assessment of the underlying plaque morphology in acute coronary syndromes, which allows for the initiation of individualized therapy. The atherothrombotic substrates for acute coronary syndromes consist of plaque rupture, erosion, and calcified nodule, whereas spontaneous coronary artery dissection, coronary artery spasm, and coronary embolism constitute rarer nonatherothrombotic etiologies. This review provides a brief overview of the data from clinical studies that have used intravascular optical coherence tomography to assess the culprit plaque morphology. We discuss the usefulness of intravascular imaging for effective treatment of patients presenting with acute coronary syndromes by percutaneous coronary intervention.

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.

Effects of stent postdilatation during primary PCI for STEMI: Insights from coronary physiology and optical coherence tomography

OBJECTIVES

This study aimed to assess the impact of stent optimization by NC-balloon postdilatation (PD) during primary-PCI for STEMI with the use of coronary physiology and intracoronary imaging.

METHODS

This was a prospective observational study (ClinicalTrials.gov:NCT02788396). Optical coherence tomography (OCT) and physiological measurements were performed immediately before and after PD with the operators blinded to all measurements. The index of microcirculatory resistance (IMR), coronary flow reserve (CFR) and fractional flow reserve (FFR) were measured. OCT analysis was performed for assessment of stent expansion, malapposition, in-stent plaque-thrombus prolapse (PTP) and stent-edge dissections (SED). The change in IMR before and after PD as a measure of microvascular injury was the primary objective of the study.

RESULTS

Thirty-two STEMI patients undergoing primary-PCI had physiological measurements before and after PD. All patients received second-generation DES (diameter 3.1 ± 0.5 mm, length 29.9 ± 10.7 mm) and postdilatation with NC-balloons (diameter 3.6 ± 0.6 mm, inflation pressure 19.3 ± 2.0 atm). IMR (44.9 ± 25.6 vs. 48.8 ± 34.2, p = 0.26) and CFR (1.60 ± 0.89 vs. 1.58 ± 0.71, p = 0.87) did not change, while FFR increased after PD (0.91 ± 0.08 vs. 0.93 ± 0.06, p = 0.037). At an individual patient level, IMR increased in half of the cases. PD improved significantly absolute and relative stent expansion, reduced malapposition, and increased PTP. There was no difference in clinically relevant SED.

CONCLUSION

In this exploratory, hypothesis-generating study, postdilatation during primary-PCI for STEMI improved stent expansion, apposition and post-PCI FFR, without a significant effect on coronary microcirculation overall. Nevertheless, IMR increased in a group of patients and larger studies are warranted to explore predictors of microcirculatory response to postdilatation.

Post-Stent Optical Coherence Tomography Findings at Index Percutaneous Coronary Intervention - Characteristics Related to Subsequent Stent Thrombosis

BACKGROUND

The association between unfavorable post-stent optical coherence tomography (OCT) findings and subsequent stent thrombosis (ST) remains unclear. This study investigated the ST-related characteristics of post-stent OCT findings at index percutaneous coronary intervention (PCI).Methods and Results:Fifteen patients with ST onset after OCT-guided PCI (ST group) were retrospectively enrolled. Post-stent OCT findings in the ST group were compared with those in 70 consecutive patients (reference group) without acute coronary syndrome onset for at least 5 years after OCT-guided PCI. The incidence of acute myocardial infarction (AMI) was higher in the ST than reference group (60.0% vs. 17.1%, respectively; P=0.0005). The incidence of incomplete stent apposition (93.3% vs. 55.7%; P=0.0064), irregular protrusion (IP; 93.3% vs. 62.8%; P=0.0214), and thrombus (93.3% vs. 51.4%; P=0.0028) was significantly higher in the ST than reference group. The maximum median (interquartile range) IP arc was significantly larger in the ST than reference group (265° [217°-360°] vs. 128° [81.4°-212°], respectively; P<0.0001). In AMI patients, the incidence of a maximum IP arc >180° was significantly higher in the ST than reference group (100% vs. 58.3%, respectively; P=0.0265).

CONCLUSIONS

IP with a large arc was a significant feature on post-stent OCT in patients with ST.

Atherothrombosis in Acute Coronary Syndromes-From Mechanistic Insights to Targeted Therapies

The atherothrombotic substrates for acute coronary syndromes (ACS) consist of plaque ruptures, erosions and calcified nodules, while the non-atherothrombotic etiologies, such as spontaneous coronary artery dissection, coronary artery spasm and coronary embolism are the rarer causes of ACS. The purpose of this comprehensive review is to (1) summarize the histopathologic insights into the atherothrombotic plaque subtypes in acute ACS from postmortem studies; (2) provide a brief overview of atherogenesis, while mainly focusing on the events that lead to plaque destabilization and disruption; (3) summarize mechanistic data from clinical studies that have used intravascular imaging, including high-resolution optical coherence tomography, to assess culprit plaque morphology and its underlying pathobiology, especially the newly described role of innate and adaptive immunity in ACS secondary to plaque erosion; (4) discuss the utility of intravascular imaging for effective treatment of patients presenting with ACS by percutaneous coronary intervention; and (5) discuss the opportunities that these mechanistic and imaging insights may provide for more individualized treatment of patients with ACS.

Optical Coherence Tomography of the Coronary Arteries

Intravascular imaging, particularly optical coherence tomography, has brought significant improvement in diagnostic and therapeutical approaches to coronary artery disease and has offered superior high-resolution visualization of coronary arteries. The ability to obtain images of intramural and transmural coronary structures allows the study of the process of atherosclerosis, effect of therapies, mechanism of acute coronary syndrome and stent failure, and performance of new devices and enables the interventional cardiologist to optimize the effect of percutaneous coronary intervention. In this review, we provide the summary of the latest published data on clinical use of optical coherence tomography as well as practical algorithm for optical coherence tomography-guided percutaneous coronary intervention for daily interventional practice.

Mid-term Clinical Outcomes of Immediate Protamine Use Following Elective Percutaneous Coronary Interventions

Bleeding complication has been considered as a serious problem in current percutaneous coronary interventions (PCI). Fortunately, several groups have already reported the effectiveness of protamine use just after PCI to immediately remove any arterial sheath. However, there is a concern that protamine reversal may increase non-occlusive thrombus and, in turn, lead to mid-term cardiovascular events such as target vessel revascularization (TVR) or stent thrombosis. Thus, the purpose of this study was to evaluate whether protamine use following elective PCI was associated with mid-term clinical outcomes. In total, 472 patients were included in this study; subsequently, they were divided into protamine group (n = 142) and non-protamine group (n = 330). The primary endpoint was the composite of ischemia-driven TVR and stent thrombosis. The median follow-up period was determined to be at 562 days. In total, 32 primary endpoints were observed during the study period, and the incidence of primary endpoints tended to be greater in the protamine group than in the non-protamine group (P = 0.056). However, the lesion length, the degree of calcification, and the prevalence of hemodialysis were significantly determined greater in the protamine group than in the non-protamine group. In the multivariate Cox proportional hazards model, the use of protamine (versus non-protamine: hazard ratio 0.542 and 95% confidence interval 0.217-1.355, P = 0.191) was deemed not to be associated with the primary endpoint after controlling legion length, calcification, and hemodialysis. In conclusion, immediate protamine use following elective PCI did not increase mid-term ischemia-driven TVR or stent thrombosis. However, immediate protamine use after PCI should be discussed further for the safety of the patient.

Impact of antiplatelet therapy on tissue prolapse at super acute phase after stenting: serial OCT study in acute coronary syndrome patients

Although drug-eluting stents have improved clinical outcomes, percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS) remains a challenging procedure in terms of thrombus management. A new-generation P2Y12 receptor inhibitor, prasugrel, provides more rapid and potent antiplatelet action compared with clopidogrel. Prasugrel achieved significant reduction of ischemic events compared with clopidogrel in ACS. The aim of this optical coherence tomography (OCT) study was to evaluate temporal changes in tissue prolapse after stenting under different antiplatelet regimens (aspirin plus prasugrel or clopidogrel) in ACS patients. A total of 119 ACS patients were randomized to either prasugrel or clopidogrel at the time of PCI. OCT analysis was available in 119 patients at baseline (just after stenting), 77 patients at 2 weeks, and 62 patients at 4 months after stenting. Cross-sectional analysis for every 1 mm was performed at in-stent and adjacent reference segment. Tissue prolapse area was calculated by lumen area minus stent area within the stented segment. Baseline patient and procedural characteristics were not different between the prasugrel and clopidogrel groups. Tissue prolapse area was significantly lower in the prasugrel compared with the clopidogrel group after stenting (0.24 ± 0.23 vs. 0.36 ± 0.23 mm², p = 0.003) and at 2 weeks (0.11 ± 0.13 vs. 0.19 ± 0.16 mm², p = 0.005). However, there was no significant difference at 4 months. In conclusion, our study suggests prasugrel was effective in reducing tissue prolapse in the super acute phase in ACS patients compared with clopidogrel. However, the effect of tissue prolapse reduction was not different up to 4 months follow-up.

Long-term Clinical Outcomes of Drug-Eluting Stent Malapposition

Previous pathologic, intravascular imaging, and clinical studies have investigated the association between adverse cardiac events and stent malapposition, including acute stent malapposition (ASM, that is detected at index procedure) and late stent malapposition (LSM, that is detected during follow-up) that can be further classified into late-persistent stent malapposition (LPSM, ASM that remains at follow-up) or late-acquired stent malapposition (LASM, newly developed stent malapposition at follow-up that was not present immediately after index stent implantation). ASM has not been associated with adverse cardiac events compared with non-ASM, even in lesions with large-sized malapposition. The clinical outcomes of LSM may depend on its subtype. The recent intravascular ultrasound studies with long-term follow-up have consistently demonstrated that LASM steadily increased the risk of thrombotic events in patients with first-generation drug-eluting stents (DESs). This association has not yet been identified in LPSM. Accordingly, it is reasonable that approaches to stent malapposition should be based on its relationship with clinical outcomes. ASM may be tolerable after successful stent implantation, whereas prolonged anti-thrombotic medications and/or percutaneous interventions to modify LASM may be considered in selected patients with first-generation DESs. However, these treatments are still questionable due to lack of firm evidences.

Residual atherothrombotic burden after primary percutaneous coronary intervention and myocardial reperfusion-An optical frequency domain imaging study

OBJECTIVES

We aimed to assess the relationship between residual in-stent atherothrombotic burden (ATB) after primary percutaneous coronary intervention (PCI) measured by optical frequency domain imaging (OFDI) using different measurement methods and myocardial blush grade (MBG).

BACKGROUND

The impact of residual ATB after primary PCI on myocardial reperfusion remains unclear.

METHODS

We prospectively included 60 ST-elevation myocardial infarction patients pretreated with aspirin and ticagrelor. OFDI volumetric quantification using planimetry (with intervals every frame or every millimeter) and semiquantitative score were used to determine ATB. Patients were divided into two groups according to final MBG 3 or <3.

RESULTS

The mean ATB was 10.08 ± 5.21%. ATB was lower in patients with final MBG 3 compared to those with impaired MBG, regardless of the measurement method (8.15 ± 5.58 vs. 11.77 ± 4.28%; p = .007 for quantification per frame; 7.8 ± 5.19 vs. 11.07 ± 4.07%; p = .009 for quantification per mm and 11.21 ± 11.75 vs. 22.91 ± 17.35; p = .003 for the semiquantitative thrombus score, respectively).

CONCLUSION

Residual post-stenting ATB remains substantial after primary PCI in STEMI patients, even when pretreated with ticagrelor and aspirin. ATB appears as a significant correlate of suboptimal myocardial reperfusion, a known surrogate of clinical outcome.

Intracoronary Optical Coherence Tomography 2018: Current Status and Future Directions

The advent of intravascular imaging has been a significant advancement in visualization of coronary arteries, particularly with optical coherence tomography (OCT) that allows for high-resolution imaging of intraluminal and transmural coronary structures. Accumulating data support a clinical role for OCT in a multitude of clinical scenarios, including assessing the natural history of atherosclerosis and modulating effects of therapies, mechanisms of acute coronary syndromes, mechanistic insights into the effects of novel interventional devices, and optimization of percutaneous coronary intervention. In this state-of-the-art review, we provide an overview of the published data on the clinical utility of OCT, highlighting the areas that need further investigation and the current barriers for further adoption of OCT in interventional cardiology practice.

The "Oculo-Appositional Reflex": Should Optical Coherence Tomography-Detected Stent Malapposition Be Corrected?

See Article by Im et al

Coronary plaque redistribution after stent implantation is determined by lipid composition: A NIRS-IVUS analysis

BACKGROUND

The composition of plaque impacts the results of stenting. The following study evaluated plaque redistribution related to stent implantation using combined near-infrared spectroscopy and intravascular ultrasound (NIRS-IVUS) imaging.

METHODS

The present study included 49 patients (mean age 66 ± 11 years, 75% males) presenting with non-ST elevation myocardial infarction (8%), unstable angina (49%) and stable coronary artery disease (43%). The following parameters were analyzed: mean plaque volume (MPV, mm3), plaque burden (PB, %), remodeling index (RI), and maximal lipid core burden index in a 4 mm segment (maxLCBI4mm). High-lipid burden lesions (HLB) were defined as by maxLCBI4mm > 265 with positive RI. Otherwise plaques were defined as low-lipid burden lesions (LLB). Measurements were done in the target lesion and in 4 mm edges of the stent before and after stent implantation.

RESULTS

MPV and maxLCBI4mm decreased in both HLB (MPV 144.70 [80.47, 274.25] vs. 97.60 [56.82, 223.45]; maxLCBI4mm: 564.11 ± 166.82 vs. 258.11 ± 234.24, p = 0.004) and LLB (MPV: 124.50 [68.00, 186.20] vs. 101.10 [67.87, 165.95]; maxLCBI4mm: 339.07 ± 268.22 vs. 124.60 ± 160.96, p < 0.001), but MPV decrease was greater in HLB (28.00 [22.60, 57.10] vs. 13.50 [1.50, 28.84], p = 0.019). Only at the proximal stent edge of LLB, maxLCBI4mm decreased (34 [0, 207] vs. 0 [0, 45], p = 0.049) and plaque burden increased (45.48 [40.34, 51.55] vs. 51.75 [47.48, 55.76], p = 0.030).

CONCLUSIONS

NIRS-IVUS defined HLB characterized more significant decreases in plaque volume by stenting. Plaque redistribution to the proximal edge of the implanted stent occurred only in LLB.

Acute myocardial infarction secondary to blunt chest trauma in motorcycle accident: A rare combination where percutaneous coronary intervention and intravascular imaging optimization are needed

Blunt chest trauma is a common occurrence in vehicle accident. Cardiac injuries following nonpenetrating thoracic trauma have been reported. ST-elevation myocardial infarction (STEMI) due to coronary artery involvement is a rare but extremely serious condition for the high risk of undetected diagnosis. Blunt thoracic trauma may obscure typical chest pain associated with cardiac ischemia especially in patients with high tolerance of pain or secondary administration of analgesic drugs. We report two consecutive cases of young adults admitted to our emergency department after motorcycle accident and concomitant anterior STEMI due to occlusion of left anterior descending artery. In both cases primary percutaneous coronary intervention with a second generation drug eluting stent implantation was successfully performed. Imaging with intravascular ultrasound and optical coherence tomography showed the mechanisms of coronary occlusion, allowing an optimal stent implantation and avoiding procedural complications in this complex setting.

Algorithmic Approach for Optical Coherence Tomography-Guided Stent Implantation During Percutaneous Coronary Intervention

Intravascular imaging plays a key role in optimizing outcomes for percutaneous coronary intervention (PCI). Optical coherence tomography (OCT) utilizes a user-friendly interface and provides high-resolution images. OCT can be used as part of daily practice in all stages of a coronary intervention: baseline lesion assessment, stent selection, and stent optimization. Incorporating a standardized, algorithmic approach when using OCT allows for precision PCI.

Role of optical coherence tomography in identifying sub-optimal stent positioning and predicting major adverse cardiac events in a comparative study with angiography: a CLIO-OPCI II sub-study

BACKGROUND

Quantitative coronary angiography (QCA) is the gold standard for evaluating correct stenting, despite its limitation in recognizing features indicative of suboptimal deployment. This subanalysis of the CLI-OPCI II registry addressed the role of optical coherence tomography (OCT) to verify whether suboptimal OCT deployment occurs in the presence of an optimal angiographic result.

PATIENTS AND METHODS

We retrospectively analyzed 125 lesions in the 105 patients with major adverse cardiac events of the CLI-OPCI II. Every lesion was evaluated with OCT and angiography, including visual and QCA assessment. Optimal angiographic result was defined as residual stenosis of less than 30% at QCA and absence of haziness at visual angiography. The following OCT features of suboptimal stenting were considered: edge dissection (linear rim of tissue with a width >200 μm), reference lumen narrowing (lumen area <4.5 mm in the presence of significant residual plaque adjacent to stent endings), and in-stent narrowing (minimum lumen area<4.5 mm).

RESULTS

Among the 125 lesions, 105 showed an optimal angiographic result. At OCT, a suboptimal positioning was common (56%). In the group of optimal angiographic results, OCT showed a suboptimal deployment in 54% of cases. Minimum lumen area of less than 4.5 mm, distal and proximal reference narrowing, and distal edge dissections were found in 30, 25, 15, and 7% of cases, respectively.

CONCLUSION

This substudy of the CLI-OPCI II showed that in patients with major adverse cardiac events, the presence of an optimal postintervention angiographic appearance with suboptimal OCT metrics is a frequent finding. Our data further support the effectiveness of OCT, which provide valuable information even in the presence of optimal poststenting angiographic results.

Three-months optical coherence tomography analysis of a biodegradable polymer, sirolimus-eluting stent

OBJECTIVE

We aimed to assess early neointimal healing by optical coherence tomography (OCT) 3 months after implantation of the ultrathin Orsiro® sirolimus-eluting stent with biodegradable polymer.

BACKGROUND

New generations of drug-eluting stents with biodegradable polymer have been developed to avoid the continued vascular irritation of durable polymers.

METHODS

In this prospective, open-label study, 34 patients received an Orsiro® sirolimus-eluting stent with biodegradable polymer. In a subgroup of patients (n = 15), the intervention was performed under OCT guidance. All patients underwent OCT-examination at three months. The primary endpoint was 3-month neointimal healing (NIH) score, calculated by weighing the presence of filling defects, malapposed and uncovered struts. Secondary endpoint was maturity of tissue coverage at 3 months.

RESULTS

At 3 months, NIH score was 13.7 (5.4-22), covered struts per lesion were 90% (84-97%), malapposed struts were 2.7% (0.8-5.4%) and rate of mature tissue coverage was 47% (42-53%). No target lesion failure occurred up to 12 months. Patients with OCT-guided stent implantation demonstrated a trend toward earlier stent healing as demonstrated by superior NIH scores (angio guided: 17.6% [8.8-26.4]; OCT-guided: 9.8% [4.0-15.5]; mean difference -8, [95%CI: -18.7-2.9], P = 0.123). This group had significantly more covered struts per lesion (angio-guided: 86% [82-90]; 95% [92-99]; mean difference 9% [95%CI: 3-15], P = 0.001).

CONCLUSION

The Orsiro® sirolimus-eluting stent with biodegradable polymer shows early vascular healing with a high rate of strut coverage at 3-month follow-up. OCT guided stent implantation had a positive impact on early vascular healing.

The impact of acute coronary syndrome on late drug-eluting stents restenosis: Insights from optical coherence tomography

The aim of the study was to investigate the optical coherence tomography (OCT)-identified difference of in-stent restenosis (ISR) tissue characteristics between patients with and without acute coronary syndrome (ACS) at index intervention.The retrospective study included 80 patients with 85 drug-eluting stent (DES) restenosis lesions. Subjects were classified according to clinical presentation at the time of de-novo lesion intervention, namely ACS and non-ACS. OCT was performed at 5 years follow-up. The frequency of malapposition, neointimal characteristics, thrombus, and minimal stent area (MSA) were evaluated.ACS group consisted of 48 (60%) patients. The mean duration from initial intervention to OCT study was 66.15 months. Malapposition was more frequent in the ACS group (25.5% vs 2.9%, P = .006), as well as a higher prevalence of thrombus in the ACS group (21.6% vs 0%, P = .015). MSA of ACS group was significantly less than that of non-ACS group (4.99 ± 1.80 vs 5.62 ± 2.08 mm, P = .018). Compared with non-ACS group, only MI group was related to smaller MSA (4.37 ± 1.39 vs 5.62 ± 2.08 mm, P = .048); The unstable angina (UA) group was not associated with a decreased MSA. The occurrence of neoatherosclerosis tended to be higher in ACS group (60.8% vs 41.2%, P = .076).In DES restenosis, an ACS presentation at initial intervention is associated with a higher incidence of malapposition, thrombus, and smaller MSA.

A comparison of intracoronary treatment strategies for thrombus burden removal during primary percutaneous coronary intervention: a COCTAIL II substudy

BACKGROUND

Manual thrombus aspiration and local drug delivery of abciximab have been proposed as a strategy to reduce thrombus burden during percutaneous coronary intervention in patients with ST elevation myocardial infarction; however, the effectiveness of these approaches, is uncertain. In this COCTAIL II substudy, we compared the effect of these strategies on prestenting and poststenting thrombus burden assessed by optical coherence tomography.

PATIENTS AND METHODS

COCTAIL II trial enrolled patients with ST elevation myocardial infarction randomized to intralesion (IL, by the ClearWay catheter) versus intracoronary (IC, by the guide catheter) abciximab bolus with or without aspiration thrombectomy (AT). The following parameters were used to quantify atherothrombotic burden: thrombus volume (TVol), maximum thrombus area (TA), and thrombus burden (TB). Primary endpoint was the comparison of prestenting TVol after the use of local drug delivery (group IL+IL abciximab plus AT) versus nonlocal drug delivery (group IC abciximab plus AT+IC).

RESULTS

The final population consisted of 59 patients undergoing both prestenting and poststenting optical coherence tomography assessment. The amount of thrombus was not significantly different in the groups with local drug delivery of abciximab versus nonlocal drug delivery in both prestenting (TVol: 18.87±26.70 vs. 19.02±18.45; TB: 26.73±12.8 vs. 25.18±13.25; and maximum TA: 59.25±18.84 vs. 53.34±19.30) and poststenting (TVol: 8.46±9.15 vs. 8.05±6.81; TB: 6.68±3.54 vs. 6.24±3.66; and maximum TA: 15.47±7.61 vs. 16.52±11.55) evaluations. A good correlation between thrombus measurements after thrombus removal techniques and intrastent thrombus was observed.

CONCLUSION

Either local drug delivery of abciximab or manual thrombus aspiration showed comparable results in terms of prestenting and poststenting thrombus burden removal.