Stent Malapposition Research Articles

Necessity sequential intermediate kissing balloon dilation for crush stenting: Further insights from metal/polymer vessel scaffolds bench testing.

Sequential intermediate kissing balloon dilation (sIKBD) is crucial for crush stenting, but it require appropriate procedure remains unclear for crush stenting. This study aims to investigate whether sIKBD is necessary and how it can be properly performed during crush stenting. Mini-crush stenting (mini-CS) and sIKBD for mini-crush stenting (sIKBD-mini-CS) using metal drug-eluting stents/polymer bioresorbable vessel scaffolds (mDES/pBVS) were emulated in bifurcation models considering the branch diameter difference, and sIKBD was added to mini-CS for pretreating side-branch (SB) stent before main-branch (MB) stenting (second figure), respectively. Micro-computed tomography was used to assess the morphological parameters of bifurcated stents including length of overlapping stent segment, residual ostial stenosis of the SB, and neocarina length using quantitative methods. Further, optical coherence tomography was to analyze the incidence of stent malapposition. Quantitative analysis demonstrated that in mDES/pBVS phantom, the neocarina length (mDES: 0.45 ± 0.10 mm vs 0.30 ± 0.09 mm, P = .005; pBVS: 0.47 ± 0.11 mm vs 0.29 ± 0.09 mm, P = .001), residual ostial stenosis at the SB (mDES: 19.37 ± 8.21% vs 12.47 ± 2.05%, P = .001; pBVS: 21.89 ± 8.54% vs 9.98 ± 3.35%, P = .035), and stent malapposition in the overlapping segment (mDES: 10.29 ± 3.31% vs 3.83 ± 0.97%, P = .001; pBVS: 12.05 ± 3.87% vs 6.40 ± 1.59%, P = .003) were lower in the sIKBD-mini-CS group than those in the mini-CS group (P < .05 for all). The results of factorial analysis showed that mDES platform tended to have better morphological indicators than the pBVS platform. Adding the sIKBD to mini-CS showed better morphologic characteristics of mDES/pBVS phantoms when compared with mini-CS. Therefore, it should be considered as a critical and proper technique for crush stenting.

Safety, efficacy, and optical coherence tomography insights into intravascular lithotripsy for the modification of non-eruptive calcified nodules: A prospective observational study.

Non-eruptive calcium nodules (CNs) are commonly seen in heavily calcified coronary artery disease. They are the most difficult subset for modification, and may result in stent damage, malapposition and under-expansion. There are only limited options available for non-eruptive CN modification. Intravascular lithotripsy (IVL) is being explored as a potentially safe and effective modality in these lesions. This study aimed to investigate the safety and efficacy of the use of IVL for the modification of non-eruptive CNs. The study also explored the OCT features of calcium nodule modification by IVL. This is a single-center, prospective, observational study in which patients with angiographic heavy calcification and non-eruptive CN on OCT and undergoing PCI were enrolled. The primary safety endpoint was freedom from perforation, no-reflow/slow flow, flow-limiting dissection after IVL therapy, and major adverse cardiac events (MACE) during hospitalization and at 30 days. MACE was defined as a composite of cardiac death, myocardial infarction (MI), and ischemia-driven target lesion revascularization (TLR). The primary efficacy endpoint was procedural success, defined as residual diameter stenosis of <30% on angiography and stent expansion of more than 80% as assessed by OCT. A total of 21 patients with 54 non-eruptive CNs undergoing PCI were prospectively enrolled in the study. Before IVL, OCT revealed a mean calcium score of 3.7 ± 0.5 and a mean MLA at CN of 3.9 ± 2.1 mm2. Following IVL, OCT revealed calcium fractures in 40 out of 54 (74.1%) CNs with an average of 1.05 ± 0.72 fractures per CN. Fractures were predominantly observed at the base of the CN (80%). Post IVL, the mean MLA at CN increased to 4.9 ± 2.3 mm2. After PCI, the mean MSA at the CN was 7.9 ± 2.5 mm2. Optimal stent expansion (stent expansion >80%) at the CN was achieved in 85.71% of patients. All patients remained free from MACE during hospitalization and at the 30-day follow-up. At 1-year follow-up, all-cause death had occurred in 3 (14.3%) patients. This single-arm study demonstrated the safety, efficacy, and utility of the IVL in a subset of patients with non-eruptive calcified nodules. In this study, minimal procedural complications, excellent lesion modifications, and favorable 30-day and 1-year outcomes were observed.

Machine Learning Constructed Based on Patient Plaque and Clinical Features for Predicting Stent Malapposition: A Retrospective Study.

Stent malapposition (SM) following percutaneous coronary intervention (PCI) for myocardial infarction continues to present significant clinical challenges. In recent years, machine learning (ML) models have demonstrated potential in disease risk stratification and predictive modeling. ML models based on optical coherence tomography (OCT) imaging, laboratory tests, and clinical characteristics can predict the occurrence of SM. We studied 337 patients from the Affiliated Hospital of Zunyi Medical University, China, who had PCI and coronary OCT from May to October 2023. We employed nested cross-validation to partition patients into training and test sets. We developed five ML models: XGBoost, LR, RF, SVM, and NB based on calcification features. Performance was assessed using ROC curves. Lasso regression selected features from 46 clinical and 21 OCT imaging features, which were optimized with the five ML algorithms. In the prediction model based on calcification features, the XGBoost model and SVM model exhibited higher AUC values. Lasso regression identified five key features from clinical and imaging data. After incorporating selected features into the model for optimization, the AUC values of all algorithmic models showed significant improvements. The XGBoost model demonstrated the highest calibration accuracy. SHAP values revealed that the top five ranked features influencing the XGBoost model were calcification length, age, coronary dissection, lipid angle, and troponin. ML models developed using plaque imaging features and clinical characteristics can predict the occurrence of SM. ML models based on clinical and imaging features exhibited better performance.

Preclinical Direct Endoluminal Assessment of Endothelialization After Flow Diversion With Microangioscopy

Background Direct endoluminal imaging, such as with our previously described microangioscope, is an emerging adjunct in endovascular cerebral aneurysm management that enables clinicians to delineate between thrombi and visualize neoepithelialization after stent placement with high resolution. The present study sought to study flow diversion in vivo under direct endoluminal imaging, and to validate our findings with histopathology. Methods In a rabbit model, we implanted each left common carotid artery with a shielded flow diverter (FD) (Medtronic Pipeline Vantage) and nonshielded FD (Medtronic Pipeline Flex) in the right common carotid artery. We studied 9 animals in 3 groups: (1) no periprocedural antiplatelet therapy, (2) aspirin 81 mg daily, and (3) aspirin 81 mg and clopidogrel 75 mg daily. FD thrombosis, stenosis, malapposition, and neoepithelialization were all evaluated by diagnostic cerebral angiography and microangioscopy after 30 days. Diagnostic cerebral angiography and angioscopic video were analyzed by independent evaluators and compared with histopathologic analysis. Results In the aspirin and dual antiplatelet therapy groups, there were no significant observed differences in stent thrombosis, stenosis, malapposition, or neoepithelialization between the shielded and non‐shielded FD groups. There was significantly more thrombus formation in Group 1. Neointimal thickness as measured by the microangioscope was highly correlated with histology (r = 0.72; P = 0.016). Interrater agreement of microangioscope videos was highest for FD thrombosis and stenosis. Conclusion In‐stent thrombosis, stenosis, malapposition, and neopithelialization demonstrated no significant difference between shielded and non‐shielded FDs. Microangioscopy measurements for neointimal thickness were highly correlated with pathology and may be a helpful adjunct to diagnostic cerebral angiography in FD follow‐up.

Clinical Implications of Acute Stent Mal-Apposition in the Left Main Coronary Artery.

Intravascular ultrasound (IVUS) has been utilized to determine acute stent mal-apposition (ASM) after percutaneous coronary intervention (PCI) in the left main coronary artery (LMCA). However, the clinical consequences of this finding remain uncertain. This research aimed to evaluate the clinical implications of ASM in the LMCA using IVUS. In this study, 408 patients who underwent successful drug-eluting stent (DES) implantation in the LMCA were evaluated. We analyzed the prevalence and characteristics of ASM and its correlation with clinical outcomes. ASM is characterized by stent struts that are not in immediate proximity to the intimal surface of the vessel wall after initial stent deployment. The observed incidence of LMCA-ASM post-successful PCI was 26.2%, both per patient and per lesion. Lesions with LMCA-ASM had a longer stent diameter, larger stent areas, and larger lumen areas compared to those without LMCA-ASM (4.0 0.5 vs. 3.7 0.4 mm, p 0.001; 9.8 2.0 vs. 9.0 1.6 , p 0.001; 12.3 1.9 vs. 10.1 2.1 , p 0.001, respectively). The mean external elastic membrane (EEM) area (odds ratio (OR): 1.418 [95% confidence interval (CI): 1.295-1.556]; p 0.001) emerged as an independent predictor of LMCA-ASM. During the observation period, LMCA-ASM did not display any association with device-oriented clinical endpoints (DoCE), which included cardiac death, target vessel-induced myocardial infarction (MI), stent thrombosis, and target lesion revascularization (TLR). Moreover, the DoCE incidence exhibited no significant disparity between patients with or without ASM (13.1 vs. 6.0%, p = 0.103). While LMCA-ASM was a not uncommon finding post-PCI, it did not correlate with adverse cardiac events in the present study.

158 Preclinical Direct Endoluminal Assessment of Endothelialization After Flow Diversion With Microangioscopy

INTRODUCTION: Endoluminal imaging (ELI) is an emerging adjunct in endovascular cerebral aneurysm management. Indirect ELI, as with optical coherence tomography, may be useful in detecting malapposition after flow diversion (FD). Direct ELI technologies, such as with our previous described microangioscope, have been shown to be able to delineate between different thrombi and visualize neoepithelialization after stent placement with high resolution. METHODS: In a rabbit model we implanted each left common carotid artery (CCA) with a shielded FD (Medtronic Pipeline Vantage) and non-shielded FD (Medtronic Pipeline Flex) in the right CCA. We studied 9 animals in 3 groups: 1) no periprocedural antiplatelet therapy, 2) aspirin 81 mg daily, 3) aspirin 81 mg and clopidogrel 75 mg daily. FD thrombosis, stenosis, malapposition, and neoepithelialization were all evaluated by diagnostic cerebral angiography (DSA) and microangioscopy after 30 days. DSA and angioscopic video were analyzed by independent evaluators and compared with histopathologic analysis. RESULTS: In the aspirin and DAPT groups, there were no significant observed differences in stent thrombosis, stenosis, malapposition, or neoepithelialization between the shielded and non-shielded FDs in each rabbit as measured by histologic analysis. There was significantly more thrombus formation in Group 1. Neointimal thickness as measured by the microangioscope was highly correlated with histology (r = 0.72, p = 0.016). Inter-rater agreement of microangioscope videos was highest for FD thrombosis and stenosis. CONCLUSIONS: There were no significant differences between in-stent thrombosis, stenosis, malapposition, or neopithelialization between shielded and non-shielded FDs. Microangioscopy measurements for neointimal thickness were highly correlated with pathology, and thus may be a helpful adjunct to DSA in FD follow-up.

Evaluation of post-dilatation on longitudinal stent deformation and postprocedural stent malapposition in the left main artery by optical coherence tomography (OCT): an in vitro study

BackgroundThe diameter of the ostial and proximal left main coronary artery can be greater than 5.0 mm. However, the diameters of the mostly available coronary drug-eluting stents (DESs) are ≤ 4.0 mm. Whether high-pressure dilatation can increase the diameter of stents from 4.0 to 5.0 mm and whether post-dilatation leads to longitudinal stent deformation (LSD) of 4.0-mm-diameter stents have rarely been studied. Therefore, this study aims to evaluate LSD and stent malapposition of six types of commercially available 4.0-mm-diameter stents in China in a 5.0-mm-diameter artificial blood vessel model by optical coherence tomography (OCT) in vitro.MethodsThe left main coronary artery was simulated by a truncated cone-shaped silicone tube. The internal diameters were 4.0 mm at one end of the silicone tube and 5.0 mm at the other end. Six different types of coronary stents widely used in China were selected for this study. Each stent was respectively implanted into the simulated blood vessel and dilated to a diameter of 4.2 mm according to the stent-balloon pressure compliance table. The stents were subjected to post-dilatation with a 5.0 × 15-mm noncompliant balloon. The LSD ratio of the longitudinal axis of each stent and stent malapposition were measured through OCT, and any fractures of the stents were determined.ResultsNone of the six types of stents fractured following post-dilatation. The longitudinal axes of the BuMA and Excrossal stents were slightly shortened, while the other stents were elongated after high-pressure post-dilatation. All stents expanded to a diameter of 5.0 mm without incomplete stent apposition, except for the Nano Plus stent, which remained malapposed after high-pressure post-dilatation.ConclusionAll 4.0-mm-diameter stents can be expanded to a diameter of 5.0 mm by noncompliant balloon post-dilatation without stent strut fracture. Most stents were found to be well apposed after high-pressure post-dilatation. However, LSD was observed after post-balloon dilatation. Stent malapposition might be positively correlated with the percentage change in stent length.

Self-Apposing Stents in Coronary Chronic Total Occlusions: A Pilot Study

This pilot study assessed the 12-month angiographic and clinical outcomes of self-apposing (SA) stents in patients undergoing chronic total occlusion (CTO) percutaneous coronary intervention (PCI). Self-apposing (SA) stents may decrease incomplete strut apposition and stent strut coverage that are common after CTO PCI. We compared 20 patients who underwent CTO PCI using SA drug-eluting stents (DESs) with 20 matched control patients who underwent CTO PCI using balloon-expandable (BE)-DESs. All patients were followed up clinically for 12 months and had coronary angiography with optical coherence tomography at the end of the follow-up period. The primary end points were stent strut malapposition and strut coverage. The secondary end point was composite major adverse cardiovascular events (MACEs) at 12 months. Both groups had high prevalence of diabetes mellitus, and most of the treated lesions were complex, with 62% having a J-CTO score of ≥3. All CTO PCI techniques were allowed for recanalisation, and 75% of the procedures were guided by intravascular ultrasound. At 12 months, the SA-DES group had fewer malapposed struts (0% [interquartile range (IQR) 0%-0%] vs 4.5% [IQR 0%-20%]; p<0.001) and uncovered struts (0.08% [IQR 0%-1.6%] vs 8.2% [IQR 0%-16%]; p<0.001). However, they showed significantly higher rates of MACEs due to clinically-driven target lesion revascularisation (45% vs 15%; p=0.038). In this pilot study, compared with conventional BE-DESs, SA-DESs used in CTO PCI were associated with fewer malapposed and uncovered stent struts but also with significantly higher rates of in-stent restenosis and MACEs, mainly caused by clinically driven target lesion revascularisation.

Thrombus burden management during primary coronary bifurcation intervention: a new experimental bench model.

Management of thrombus burden during primary percutaneous coronary intervention (pPCI) is a key-point, given the high risk of stent malapposition and/or thrombus embolization. These issues are especially important if pPCI involves a coronary bifurcation. Herein, a new experimental bifurcation bench model to analyze thrombus burden behavior was developed. On a fractal left main bifurcation bench model, we generated standardized thrombus with human blood and tissue factor. Three provisional pPCI strategies were compared (n = 10/group): 1) balloon-expandable stent (BES), 2) BES completed by proximal optimizing technique (POT), and 3) nitinol self-apposing stent (SAS). The embolized distal thrombus after stent implantation was weighed. Stent apposition and thrombus trapped by the stent were quantified on 2D-OCT. To analyze final stent apposition, a new OCT acquisition was performed after pharmacological thrombolysis. Trapped thrombus was significantly greater with isolated BES than SAS or BES+POT (18.8 ± 5.8% vs. 10.3 ± 3.3% and 6.2 ± 2.1%, respectively; p < 0.05), and greater with SAS than BES+POT (p < 0.05). Isolated BES and SAS tended show less embolized thrombus than BES+POT (5.93 ± 4.32 mg and 5.05 ± 4.56 mg vs. 7.01 ± 4.32 mg, respectively; p = NS). Conversely, SAS and BES+POT ensured perfect final global apposition (0.4 ± 0.6% and 1.3 ± 1.3%, respectively, p = NS) compared to isolated BES (74.0 ± 7.6%, p < 0.05). This first experimental bench model of pPCI in a bifurcation quantified thrombus trapping and embolization. BES provided the best thrombus trapping, while SAS and BES+POT achieved better final stent apposition. These factors should be taken into account in selecting revascularization strategy.

Role of Optical Coherence Tomography in Coronary Interventions

Optical coherence tomography (OCT) is an optical analog of intravascular ultrasound (IVUS) used to examine the coronary arteries with a higher resolution. Based on polarization properties, OCT can differentiate tissue characteristics (fibrous, calcified, or lipid-rich plaque) and identify vulnerable plaque. Because of the strong attenuation of light by blood, OCT requires a field of view that is free of blood. OCT can provide detailed information on coronary intervention such as dissection, tissue prolapse, thrombus stent malapposition, and under expansion. Despite the diagnostic utility of OCT, facilitated by its high resolution, the impact of intracoronary OCT on clinical practice has thus far been limited for various reasons. Herein, we provide a comprehensive up-to-date overview on the utility of OCT in coronary artery disease, specifically acute coronary syndromes along with a summary of the evidence, work in progress, and future directions.

Tissue responses to everolimus-eluting stents implanted in severely calcified lesions following atherectomy

Histopathological examination has revealed that stents on severely calcified plaques were associated with delayed vascular healing. Although atherectomy devices can increase the number of malapposed struts, tissue responses to implanted drug eluting stents in atherectomy patients remain largely unknown. This retrospective observational study included 30 patients who underwent atherectomy and everolimus-eluting stent (EES) deployment for severely calcified coronary lesions (biodegradable polymer EES (BP-EES), n = 15; durable polymer EES (DP-EES), n = 15). Optical coherence tomography was carried out at baseline and follow-up, and struts with acute stent malapposition (ASM) were categorized as struts on modified calcium (mod-Ca), non-modified calcium (non-mod-Ca), or non-calcium (non-Ca). Adequate vascular healing, defined as ASM resolution with neointimal coverage, was compared between the BP-EES and DP-EES groups. Multivariate linear regression analysis using a generalized estimated equation revealed that BP-EES use was associated with significantly better adequate vascular healing compared with DP-EES (odds ratio [OR]: 3.691, 95% confidence interval [CI] 1.175–11.592, P = 0.025). adequate vascular healing was associated with the underlying plaque morphology (mod-Ca vs non-mod-Ca: OR 2.833, 95% CI 1.491–5.384, P = 0.001; non-Ca vs non-mod-Ca: OR 1.248, 95% CI 0.440–3.543, P = 0.677). This study demonstrates that drug-eluting stent selection and calcium modification are possible factors affecting vascular healing of malapposed struts in severely calcified lesions.Graphical

Impact of coronary bifurcation angle on stent malapposition in a randomized comparison between proximal optimization technique followed by side branch dilatation and kissing balloon inflation.

The impact of coronary bifurcation angle (BA) on incomplete stent apposition (ISA) after crossover stenting followed by side branch (SB) intervention has not been established. A total of 100 crossover stentings randomly treated with proximal optimization technique followed by short balloon dilation in the SB (POT-SBD group, 48 patients) and final kissing balloon technique (KBT group, 52 patients) were analyzed in the PROPOT trial. Major ISA with maximum distance>400μm and its location was determined using optical coherence tomography before SB intervention and at the final procedure. The BA was defined as the angle between the distal main vessel and SB. Optimal POT was determined when the difference in stent volume index between the proximal and distal bifurcation was greater than the median value (0.86mm3/mm) before SB intervention. Major ISA was more frequently observed in the POT-SBD than in the KBT group (35% versus 17%, p<0.05). In the POT-SBD group, worsening ISA after SBD was prominent at the distal bifurcation. The BA was an independent predictor of major ISA (odds ratio 1.04, 95% confidence interval 1.00-1.07, p<0.05) with a cut-off value of 59.5° (p<0.05). However, the cases treated with optimal POT in the short BA (<60°) indicated the lowest incidence of major ISA. In the KBT group, BA had no significant impact. A wide BA has a potential risk for the occurrence of major ISA after POT followed by SBD in coronary bifurcation stenting.

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.

Aneurysm Isolation is Associated with Complete Occlusion of Aneurysms After Flow Diverter Treatment.

Some aneurysms remain patent after treatment with flow diverters (FD) due to residual blood flow in the aneurysm. Several studies have proposed that branches and residual flow are associated with delayed aneurysm occlusion. We propose that aneurysm isolation (i.e., the complete disconnection of the aneurysm from surrounding vessels) might be a possible factor facilitating aneurysm occlusion. This study aimed to determine if aneurysm isolation was a factor associated with aneurysm occlusion after FD treatment. We reviewed 80 internal carotid artery (ICA) aneurysms treated with FDs between October 2014 and April 2021. Aneurysm isolation was assessed in high-resolution cone-beam computed tomograms at the end of each treatment. Aneurysms with incorporated branches and those with connections to other branches due to stent malapposition were deemed to be nonisolated. Other factors, such as patient age, sex, anticoagulant use, aneurysm size, adjunct coil use, and the presence of incorporated branches, were considered. The degree of aneurysm occlusion (complete or incomplete) was assessed by follow-up angiograms 12 months after treatment. Complete occlusion was achieved in 57 of 80 aneurysms (71%). Completely occluded aneurysms had a significantly higher ratio of isolation compared to incompletely occluded aneurysms (91.2% vs. 69.6%, P = 0.032). Multivariate logistic regression analysis showed that aneurysm isolation was the sole significant predictor of complete aneurysm occlusion (odds ratio, OR 19.38; 95% confidence interval, CI 2.280-164.657; P = 0.007). Aneurysm isolation is a significant factor contributing to complete occlusion after FD treatment.

Incidence, risk factors, and clinical sequelae of incomplete stent apposition after sirolimus-eluting stent.

Incomplete stent apposition has been documented after sirolimus-eluting stent implantation. However, its clinical sequelae remain controversial. To identify the incidence and its clinical consequences of ISA, IVUS was performed on 78 patients. In spite of well apposition immediately after the deployment, late stent malapposition occurred after 6-months follow-up. A total of 7 patients who received SES showed ISA. There were no significant differences in IVUS measurements between patients with or without ISA. However, there was an increase in external elastic membrane area in ISA group than non-ISA group (19.69 ± 3.50 vs. 15.05 ± 2.56 mm2, P<0.05). There were positive clinical events for ISA cases at 6-months clinical follow-up. Univariate and multivariable analyses indicated that hs-CRP, miR-21, and MMP-2 were risk factor for ISA. ISA was observed in 9% of patients after SES implantation, which was related to vessel positive remodeling. The incidence of MACEs in patients with ISA was higher than those without ISA. However, careful long-term follow-up remains to be clarified.

Intravascular Ultrasound Guided Intervention in Calcified Coronary Lesions Showed Good Clinical Outcomes during One Year Follow-Up.

Calcified coronary lesions can cause stent under-expansion, malapposition, and polymer degradation, hence increasing the risk of adverse clinical outcomes. Percutaneous coronary intervention (PCI) guided by intravascular ultrasound (IVUS) has been used regularly to improve outcomes. Our primary aim was to evaluate the clinical efficacy of IVUS-guided PCI in calcified coronary lesions. From August 2018 to December 2021, we prospectively included 300 patients in the CAPIRO study (CAlcified plaque in patients receiving Resolute Onyx®) at three educational hospitals in Jeonbuk Province. We studied 243 patients (265 lesions) who were followed up for over a year. Based on coronary calcification by IVUS analysis, the patient population was categorized into two groups (Group I: non/mild calcification; Group II: moderate/severe calcification (maximum calcium arc >180° and calcium length > 5 mm)). One-to-one Propensity Score Matching was used to match the baseline characteristics. The stent expansion rate was analyzed by recent criteria. The primary clinical outcome was Major Adverse Cardiac Events (MACE), which included Cardiac death, Myocardial Infarction (MI), and Target Lesion Revascularization (TLR). After follow-up time, the MACE rate in Group I was 1.99%, comparable to Group II's 1.09% (p = 0.594). The components of MACE did not significantly differ between the two groups. Based on absolute MSA or MSA/MVA at MSA site criteria, the stent expansion rate in Group II was lower than that of Group I. Nevertheless, based on recent relative criteria, the stent expansion rate in both groups was comparable. After more than a year of follow-up, IVUS-guided PCI in moderate/severe calcification lesions was associated with good clinical outcomes, which was comparable with non/mild calcification lesions. Future studies with a larger sample size and a more extended follow-up period are required to clarify our findings.

P42 ACUTE STENT THROMBOSIS IN CATH LAB DURING OPTIMIZED PCI: HOW TO RECOGNIZE IT AND POSSIBLE TREATMENT

Abstract Angiographic Acute Stent Thrombosis occur in 0.5%–2% of procedures.OCT–PCI or Optimized PCI represents a new approach particularly indicated in complex high thrombotic risk lesions, in patients at high bleeding risk with need for short DAPT and in the treatment of vulnerable plaques. Post–stent OCT thrombus finding was defined in previous studies as mass with diameter ≥250μm attached to the stent struts, was present until 40% of cases and is associated with definite angiographic thrombosis. Outcome of OCT thrombus is generally favorable although in about 25% there may be a progression. Case 1: 75–y smoker female with hypertension and atrial fibrillation on NOAC therapy presented in ICU with NSTEMI. At angiography: 75% stenosis focal plaque at proximal circumflex (Fig1A). At OCT vulnerable plaque: ulcerated with intimal flap &amp;lt; 90°, thin fibrous cap 20 µm, MLA 2.17mm² and AS 63%, intimal micro–calcifications and cholesterol crystals (Fig1C). We implanted DES with post–dilatation. Treatment was Cangrelor, heparin 100 IU/kg and ASA 250 mg ev. OCT showed acute 660 µm thrombosis of the stent body although there was perfect angiographic result (Fig1D+B). Further multiple balloon dilatation of the stent was carried out with thrombosis persistence on OCT control (Fig1E) and new appearance of multiple thromboses adhering to the intravascular side stent struts (Fig1F–G). Switch from Cangrelor to Tirofiban was done. Patient‘s clinical course was uneventful with discharge after six days on triple antithrombotic therapy with low–dose NOAC, ASA and clopidogrel.Case 2: 63–y smoker man arrived in cath lab for anterior STEMI. He had already taken ASA 300 mg ev and Ticagrelor 180 mg oral bolus about 60 minutes earlier in the ambulance. In Cath Lab was done heparin 100 IU/kg. P–PCI was performed for acute sub–occlusion (Fig2A) of the ostial DA treated by pre–dilation, DES implantation on Left Main–DA and multiple post–dilations according to the POT technique. OCT control showing extensive stent malapposition (860 µm) with evidence of multiple thromboses adhering to the stent struts on Left Main (diameter 410 µm) although there was perfect angiographic result (Fig2B–E). Procedure was optimized by adequate post–dilatation of the LM and administration of Abciximab. Patient‘s clinical course was uneventful with discharge after five days on ASA and Ticagrelor. Conclusions Post–stent OCT thrombus may guide the choice of use of Glicoprotein IIb/IIIA Inhibitors in Cath Lab.

The POT-PUFF sign: an angiographic mark of stent malapposition during proximal optimisation.

The POT-PUFF sign: an angiographic mark of stent malapposition during proximal optimisation.

Calcified coronary nodule: Tip of the iceberg on a road full of thorns.

Key Points Nodular coronary calcium (NC) is infrequent, is associated with advanced age and chronic kidney disease and may be responsible for acute coronary syndromes. NC leads to a greater incidence of stent malapposition and target lesion revascularization, and intravascular imaging often shows recurrence of the calcified nodule within the stent. Clinical outcomes are worse after stenting lesions with calcified nodules, but randomized studies are necessary to determine the best management strategy.

Impact of acute and persistent stent malapposition after percutaneous coronary intervention on adverse cardiovascular outcomes.

The association of coronary stent malapposition (SM) and adverse clinical outcomes after percutaneous coronary intervention (PCI) remains unclear. We aimed to perform a systematic review and meta-analysis of randomized and observational studies to assess the association between acute and persistent SM detected using intravascular ultrasound (IVUS) or optical coherence tomography (OCT) and adverse cardiovascular outcomes. Available studies were identified through a systematic search of PubMed, reference lists of relevant articles, and Medline. Main efficacy outcomes of interest were: device-oriented composite endpoint (DoCE, including cardiac death, myocardial infarction [MI], target lesion revascularization [TLR], and stent thrombosis [ST]), major safety events (MSE, including cardiac death, MI and ST), TLR, and ST. A sensitivity analysis regarding the impact of major malapposition was also performed. A total of 9 studies enrolling 6497 patients were included in the meta-analysis. After a mean follow up of 24±14 months, overall acute and/or persistent malapposition was not significantly associated with the occurrence of all the outcomes of interest, including DoCE (risk ratio [RR] 1.00, 95% confidence interval [CI, 0.79-1.26], P=0.99), MSE (RR 1.42, 95%CI [0.81-2.50], P=0.22), TLR (RR 0.84, 95%CI [0.59-1.19], P=0.33), and ST (RR 1.16, 95%CI [0.48-2.85], P=0.74). In the sensitivity analysis, we found a significant increase of MSE in patients with major malapposition (RR 2.97, 95%CI [1.51-5.87], P=0.001). Acute and persistent SM were not overall associated with adverse cardiovascular clinical outcomes at follow-up. However, major malapposition was associated with an increased risk of major safety events, including cardiac death, MI and ST. These findings should be taken into account during stent implantation and PCI optimization.