Intravascular Imaging Research Articles

Application of intravascular physiology methods in clinical practice: two-year data from the Russian registry

Aim. To analyze the use in clinical practice of intravascular coronary assessment methods based on two-year data from the Russian Registry on the Use of Intravascular Imaging and Physiology.Material and methods. Since 2021, the Russian Registry on the Use of Intravascular Imaging and Physiology has included data from 7967 studies in 3932 patients, of which 3086 (38,7%) were studies of intravascular physiology. In 2021, 13 branches from 9 cities participated in the registry, in 2022 — 20 branches from 11 cities. For chronic coronary artery disease, 2484 (80,5%) studies were performed, for acute coronary syndrome (ACS) — 598 (19,4%).Results. In 2022, the registry included 1,9 times more intravascular functional studies compared to 2021. The contribution of different clinics was uneven — 75,7% of studies were performed in three departments. The use of non-hyperemic indexes prevailed over hyperemic ones (58%), and in ACS they were used three times more often. All coronary arteries were examined, most often the anterior descending artery. As a primary diagnosis, 1968 (63,8%) studies were performed, while for the purpose of dynamic control — 122 (3,9%), at the surgical stage — 996 (32,3%). In 85,5% (n=2638) of observations, the functional assessment of stenosis hemodynamic significance directly influenced the treatment tactics.Conclusion. The registry data indicate the significant role of functional methods among intravascular diagnostic options in the practice of domestic clinics participating in the registry. The registry demonstrated their use as a primary diagnosis 2 times more often than for coronary artery stenting. Some indications for the active use of intravascular physiology methods (in acute coronary syndrome, left coronary artery involvement) are currently controversial and require further research.

Two-year real world clinical outcomes after intravascular imaging device guided percutaneous coronary intervention with ultrathin-strut biodegradable-polymer sirolimus-eluting stent

BackgroundThere are little clinical data on imaging-guided percutaneous coronary intervention (PCI) 1 year after the biodegradable-polymer sirolimus-eluting stents (BP-SES) implantation, when the polymer disappears. MethodsWe retrospectively analyzed 2455 patients who underwent successful PCI with BP-SES or durable-polymer everolimus-eluting stents (DP-EES) between September 2011 and March 2021, and compared 2-year clinical outcomes of BP-SES (n = 459) with DP-EES (n = 1996). The outcome measures were target lesion revascularization (TLR) and major adverse cardiac events (MACE), defined as a composite of cardiac death, myocardial infarction, target vessel revascularization, and stent thrombosis. Multivariate analysis using the Cox proportional hazard model and inverse probability weighting (IPW) analysis based on the propensity score were used to evaluate the clinical outcomes. ResultsThe 2-year cumulative incidences of TLR (BP-SES: 4.9% vs. DP-SES: 6.1%, p = 0.304) and MACE (10.3% vs. 12.5%, p = 0.159) were similar between the two groups. Multivariable and IPW analysis revealed the risks of TLR (p = 0.388 and p = 0.500) and MACE (p = 0.139 and p = 0.083) also had no significant difference. There was a significant interaction between none/mild and moderate/severe calcification with respect to MACE and TLR (adjusted p for interaction = 0.036 and 0.047, respectively). The risk of MACE was significantly lower in BP-SES than in DP-EES in lesions with none/mild calcification (adjusted hazard ratio [aHR]: 0.53; 95% confidence interval [CI]: 0.30–0.91), while it was similar in those with moderate/severe calcification (aHR: 0.95; 95% CI: 0.58–1.55). ConclusionsCompared with DP-EES, BP-SES demonstrated durable 2-year clinical outcomes. However, BP-SES showed better clinical performance than DP-EES for lesions with none/mild calcification.

Efficacy of human experts and an automated segmentation algorithm in quantifying disease pathology in coronary computed tomography angiography: A head-to-head comparison with intravascular ultrasound imaging

BackgroundCoronary computed tomography angiography (CCTA) analysis is currently performed by experts and is a laborious process. Fully automated edge-detection methods have been developed to expedite CCTA segmentation however their use is limited as there are concerns about their accuracy. This study aims to compare the performance of an automated CCTA analysis software and the experts using near-infrared spectroscopy-intravascular ultrasound imaging (NIRS-IVUS) as a reference standard. MethodsFifty-one participants (150 vessels) with chronic coronary syndrome who underwent CCTA and 3-vessel NIRS-IVUS were included. CCTA analysis was performed by an expert and an automated edge detection method and their estimations were compared to NIRS-IVUS at a segment-, lesion-, and frame-level. ResultsSegment-level analysis demonstrated a similar performance of the two CCTA analyses (conventional and automatic) with large biases and limits of agreement compared to NIRS-IVUS estimations for the total atheroma (ICC: 0.55 vs 0.25, mean difference:192 (-102-487) vs 243 (-132-617) and percent atheroma volume (ICC: 0.30 vs 0.12, mean difference: 12.8 (−5.91-31.6) vs 20.0 (0.79–39.2). Lesion-level analysis showed that the experts were able to detect more accurately lesions than the automated method (68.2 ​% and 60.7 ​%) however both analyses had poor reliability in assessing the minimal lumen area (ICC 0.44 vs 0.36) and the maximum plaque burden (ICC 0.33 vs 0.33) when NIRS-IVUS was used as the reference standard. ConclusionsConventional and automated CCTA analyses had similar performance in assessing coronary artery pathology using NIRS-IVUS as a reference standard. Therefore, automated segmentation can be used to expedite CCTA analysis and enhance its applications in clinical practice.

Clinical Case of IVUS-Guided Coronary Artery Stenting in a Patient with Chronic Renal Failure

Introduction. An expanding number of indications for PCI in patients with coronary heart disease and severe concomitant pathology are accompanied by a growing number of patients with chronic renal failure. Contrast-induced nephropathy (CIN) is recognized as a severe complication, aggravating the course of the underlying disease, and, moreover, reducing the life expectancy of the patients. Modern intravascular imaging technologies are widely implemented in real clinical practice of endovascular surgery. In the context of increasing number of PCI performed in patients with severe concomitant pathology, the IVUS-guidance will improve the quality of stenting, and, importantly, lessen the risks of CIN due to the reduction in contrast volume. Materials and methods. The paper presents a clinical case of IVUSguided stenting of the right coronary artery without contrast agent in a patient with chronic kidney disease and the following diagnosis: “Coronary heart disease. Effort angina, class III (dyspnea as anginal equivalent). Balloon angioplasty and stenting of circumflex artery and LAD. Hyperlipidemia 2a. Atherosclerosis of the aorta, brachiocephalic and coronary arteries. Stage 3 hypertension. Controlled Hypertension. Level IV CVD risk. Type 2 diabetes mellitus. Target glycated hemoglobin is less than 7.5%. Grade 2 obesity, exogenous-constitutional. Renal microlithiasis. CKD stage 4 (GFR 29 ml/min/1.73m2). Cerebrovascular disease. Chronic cerebral ischemia.” Results and discussion. In the described clinical case, a complete myocardial revascularization was achieved using IVUS-guidance and minimal amount of contrast agent in a patient with severe CKD. The advantage of minimally invasive endovascular interventions in a complex category of patients, demonstrated by the case, implies expanded possibilities for providing high-tech care to patients with significant limitations in the use of contrast agents due to severe CKD with a high risk of CIN. Conclusion. Today, an increasing number of X-ray operating rooms in Russia are equipped with intravascular technologies, ensuring their wider use. The skills and knowledge in using IVUS imply rare application of contrast agents, thereby lessening the risk of CKD and, as a consequence, improving the prognosis of patients with reduced renal function and high risk of CKD.

Capabilities of intravascular imaging techniques in the diagnosis of cardiac allograft vasculopathy: Literature review

Cardiac allograft vasculopathy (CAV) is a coronary heart disease (CHD), arising after an orthotopic heart transplant (OHT), and it is one of the leading causes of death in heart recipients. The probability of death is 10%. CAV can manifest as early as 1 year after OHT. Patients do not have pain syndrome that is typical for CHD due to cardiac denervation. The first clinical manifestations may be congestive heart failure, ventricular arrhythmias or even sudden cardiac death. Coronary angiography is the routine technique for CAV detection. However, it is not sensitive enough (about 44%) for CAV detection at an early stage of the disease. Today, intravascular imaging methods (intravascular ultrasound, optical coherence tomography), which allow the evaluation of the morphology of coronary artery lesions, including CAV, have become widespread. This article is devoted to the modern capabilities of intravascular imaging methods in the diagnosis of CAV. CAV is the main cause of myocardial infarction and chronic heart failure in patients after OHT. Intravascular imaging techniques allow early detection of this condition and prevention of unfavorable outcomes in a complex category of heart recipients. Given the advantages of optical coherence tomography (OCT) and disadvantages of intravascular ultrasound (IVUS), OCT appears to be a more informative method of CAV detection.

Impact of iodinated contrast shortage on contrast-associated acute kidney injury: a single center experience

Background In March 2022, a COVID-19 outbreak disrupted the global supply of iodine contrast media (ICM). Healthcare systems implemented contrast-saving strategies to maintain their remaining ICM supplies. This study sought to determine the impact of contrast shortage on the incidence of contrast-associated acute kidney injury (CA-AKI). Methods This was a retrospective study of 265 patients undergoing 278 percutaneous coronary interventions (PCI) during 4-month periods prior to (9/1/2021 to 12/31/2021) and during (5/1/2022 to 8/31/2022) contrast shortage at a single center. The primary endpoint was the incidence of CA-AKI between study periods. Results A total of 148 and 130 PCIs were performed before and during contrast shortage, respectively. The incidence of CA-AKI significantly decreased from 11.5% to 4.6% during contrast shortage (P = 0.04). During the shortage, average contrast volume per PCI was significantly lower (123 ± 62 mL vs 88 ± 46 mL, P < 0.001), while coronary imaging was significantly higher (34.3% vs 50%, P = 0.009) compared to preshortage. All-cause mortality at discharge was comparable between study periods (2.8% vs 3.3%, respectively; P = 0.90). Conclusion The scarcity of ICM for PCI procedures in this single-center experience was associated with a significant increase in the utilization of intravascular imaging and a significant reduction in CA-AKI.

Intravascular Imaging in Ultra-Low or Zero-Contrast Percutaneous Coronary Interventions: The Time Is Now?

Ultra-low contrast percutaneous coronary interventions (ULPCIs) are a novel field of interventional cardiology, aiming to reduce the risk of contrast-induced nephropathy (CIN), which is a well-described adverse event after angiography. CIN is a well-described adverse event following PCI, especially in high-risk patients, i.e., patients with an already deteriorating renal function or chronic kidney disease, as well as patients of advanced age or requiring an increased amount of contrast during their intervention. Among the techniques described for ULPCI procedures, intravascular imaging guidance seems a promising option, as it allows lesion recognition and characterization, stent implantation, and PCI optimization. Intravascular ultrasound (IVUS) is the modality most commonly used, as it does not require contrast injection, contrary to optical coherence tomography (OCT). Several clinical trials, assessing IVUS in the context of ULPCI, have shown that it can be safely used in this setting while offering a substantial reduction in contrast media volume, as well as renal adverse outcomes. This review aims to describe the need for ULPCI and technical considerations regarding the use of intravascular imaging in this setting, as well as analyze the available evidence from clinical trials regarding the safety and efficacy of IVUS-ULPCI, in order to provide a comprehensive summary for practicing physicians.

Mechanisms of Very Late Stent Thrombosis in Japanese Patients as Assessed by Optical Coherence Tomography

BackgroundAlthough very late stent thrombosis (VLST) remains an important concern, the underlying etiology and clinical characteristics are not fully elucidated in Japanese patients who undergo intravascular imaging-guided percutaneous coronary intervention (PCI) regularly. MethodsWe identified 50 VLST lesions (bare-metal stent [BMS] [n = 16], first-generation drug-eluting stent [DES] [n = 14] and newer-generation DES [n = 20]) in patients managed in our institutes. The underlying mechanism of VLST was assessed by optical coherence tomography (OCT), and the major etiology of each lesion was determined. The aim of this study was to explore the mechanisms of VLST of BMSs and DESs in Japanese patients. ResultsThe median duration since stent implantation was 10 years (range: 1-20). The most frequent etiology of VLST was neoatherosclerotic rupture (44%), followed by neointimal erosion (24%). Edge disease (10%) and evagination (10%) were similarly observed. Malapposition (8%) was deemed to be acquired late by looking at intravascular imaging from the index procedure. Uncovered struts (2%) and in-stent calcified nodule (2%) were the least frequent etiologies. Regardless of etiology, signs of neoatherosclerosis were present in most lesions (82%). Most patients received single (68%) or dual (8%) antiplatelet therapy or oral anticoagulation alone (4%), whereas a considerable proportion of patients discontinued medication (20%). Regarding the treatment strategy, drug-coated balloon was the most frequent strategy (56%), followed by implantation of newer DESs (34%). ConclusionsVarious mechanisms have been identified in Japanese patients with VLST. In these patients, biological responses seemed to be more relevant than the index procedure-related factors.

Coupled Contour Regression for Efficient Delineation of Lumen and External Elastic Lamina in Intravascular Ultrasound Images.

Automatic delineation of the lumen and vessel contours in intravascular ultrasound (IVUS) images is crucial for the subsequent IVUS-based analysis. Existing methods usually address this task through mask-based segmentation, which cannot effectively handle the anatomical plausibility of the lumen and external elastic lamina (EEL) contours and thus limits their performance. In this article, we propose a contour encoding based method called coupled contour regression network (CCRNet) to directly predict the lumen and EEL contour pairs. The lumen and EEL contours are resampled, coupled, and embedded into a low-dimensional space to learn a compact contour representation. Then, we employ a convolutional network backbone to predict the coupled contour signatures and reconstruct the signatures to the object contours by a linear decoder. Assisted by the implicit anatomical prior of the paired lumen and EEL contours in the signature space and contour decoder, CCRNet has the potential to avoid producing unreasonable results. We evaluated our proposed method on a large IVUS dataset consisting of 7204 cross-sectional frames from 185 pullbacks. The CCRNet can rapidly extract the contours at 100 fps. Without any post-processing, all produced contours are anatomically reasonable in the test 19 pullbacks. The mean Dice similarity coefficients of our CCRNet for the lumen and EEL are 0.940 and 0.958, which are comparable to the mask-based models. In terms of the contour metric Hausdorff distance, our CCRNet achieves 0.258 mm for lumen and 0.268 mm for EEL, which outperforms the mask-based models.

Intravascular Optical Coherence Tomography Utilizing a Miniature Piezoelectric-Driven Probe.

Intravascular optical coherence tomography (IV-OCT) is crucial for evaluating lumen dimensions and guiding interventional procedures. However, traditional catheter-based IV-OCT faces challenges in achieving precise and full-field 360° imaging in tortuous vessels. Current IV-OCT catheters that employ proximal actuators and torque coils are susceptible to non-uniform rotational distortion (NURD) in tortuous vessels, while distal micromotor-driven catheters struggle with complete 360° imaging due to wiring artifacts. In this study, we developed a miniature optical scanning probe with an integrated piezoelectric-driven fiber optic slip ring (FOSR) to facilitate smooth navigation and precise imaging within tortuous vessels. The FOSR features a coil spring-wrapped optical lens serving as a rotor, enabling efficient 360° optical scanning. The structurally-and-functionally-integrated design significantly streamlines the probe (with a diameter of 0.85 mm and a length of 7 mm) while maintaining an excellent rotational speed of 10,000 rpm. High-precision 3D printing technology ensures accurate optical alignment of the fiber and lens inside the FOSR, with a maximum insertion loss variation of 2.67 dB during probe rotation. Finally, a vascular model demonstrated smooth probe insertion into the carotid artery, and imaging of oak leaf, metal rod phantoms, and ex vivo porcine vessels verified its capabilities for precise optical scanning, comprehensive 360° imaging, and artifact elimination. The FOSR probe exhibits small size, rapid rotation, and optical precision scanning, rendering it exceptionally promising for cutting-edge intravascular optical imaging techniques.

Intravascular Imaging in Patients With Complex Coronary Lesions and Chronic Kidney Disease

As patients with chronic kidney disease (CKD) are more likely to have complex coronary lesions, intravascular imaging guidance in percutaneous coronary intervention (PCI) for this population could be potentially beneficial. To investigate whether the outcomes of intravascular imaging-guided procedural optimization would be different according to the presence of CKD. This was a prespecified substudy of RENOVATE-COMPLEX-PCI, a recently published multicenter randomized clinical trial in Korea studying the benefits of intravascular imaging for complex coronary lesions. Patients with complex coronary lesions, with or without CKD, were enrolled between May 2018 and May 2021. Data were analyzed from January to June 2023. PCI in each group was done either under the guidance of intravascular imaging or angiography alone. The primary end point was target vessel failure (TVF) at the 3-year point, defined as a composite of cardiac death, target vessel-related myocardial infarction, or clinically driven target vessel revascularization. A total of 1639 patients (1300 male [79.3%]) treated with PCI for complex coronary lesions were stratified into CKD (296 participants) and non-CKD (1343 participants) groups. The mean (SD) age of each group was 70.3 (9.4) and 64.5 (10.1) years, and mean (SD) estimated serum creatinine was 2.9 (5.3) and 0.8 (0.2) mg/dL for CKD and non-CKD groups, respectively. Intravascular imaging-guided revascularization was associated with significantly lower incidence of the primary end point compared with angiography-guided revascularization in both CKD (13.3% vs 23.3%; hazard ratio [HR], 0.51; 95% CI, 0.27-0.93; P = .03) and non-CKD (6.4% vs 9.9%; HR, 0.66; 95% CI, 0.44-0.99; P = .05) groups. The significantly lower incidence of the primary end point was mainly associated with the lower risk of cardiac death or target vessel-related myocardial infarction (9.4% vs 22.2%; HR, 0.39; 95% CI, 0.20-0.76; P = .006) in the CKD group and by target vessel revascularization (3.0% vs 5.5%; HR, 0.55; 95% CI, 0.30-0.99; P = .05) in the non-CKD group. Those with a glomerular filtration rate of at least 30 mL/min/1.73m2 and less than 60 ml/kg/1.73m2 showed the greatest benefit from imaging-guided complex PCI (8.8% vs 21.2%; HR, 0.28; 95% CI, 0.11-0.68; P = .02). In this prespecified cohort substudy of the Randomized Controlled Trial of Intravascular Imaging Guidance versus Angiography-Guidance on Clinical Outcomes After Complex Percutaneous Coronary Intervention trial, intravascular imaging guidance showed clinical benefit over angiography guidance in reducing the risk of TVF, regardless of the presence of CKD. The greatest benefits of imaging-guided complex PCI were observed in stage 3 CKD. ClinicalTrials.gov Identifier: NCT03381872.

International survey of chronic total occlusion percutaneous coronary intervention operators.

Contemporary chronic total occlusion (CTO) percutaneous coronary intervention (PCI) practice has received limited study. To examine the contemporary CTO PCI practice. We performed an online, anonymous, international survey of CTO PCI operators. Five hundred forty-fiveCTO PCI operators and 190 interventional cardiology fellows with an interest in CTO PCI participated in this survey. Almost half were from the United States (41%), most (93%) were men, and the median h/week spent in the hospital was 58. Median annual case numbers were 205 (150-328) for PCIs and 20 (5-50) for CTO PCIs. Almost one-fifth (17%) entered CTO cases into registries, such as PROGRESS-CTO (55%) and EuroCTO (20%). More than one-third worked at academic institutions (39%), 31% trained dedicated CTO fellows, and 22% proctored CTO PCI. One-third (34%) had dedicated CTO PCI days. Most (51%) never discharged CTO patients the same day, while 17% discharged CTO patients the same day >50% of the time. After successful guidewire crossing, 38% used intravascular imaging >90% of the time. Most used CTO scores including J-CTO (81%), PROGRESS-CTO (35%), and PROGRESS-CTO complications scores (30%). Coronary artery perforation was encountered within the last month by 19%. On a scale of 0-10, the median comfort levels in treating coronary artery perforation were: covered stents 8.8 (7.0-10), coil embolization 5.0 (2.1-8.5), and fat embolization 3.7 (0.6-7.3). Most (51%) participants had a complication cart/kit and 25% conducted regular complication drills with catheterization laboratory staff. Contemporary CTO PCI practices vary widely. Further research on barriers to following the guiding principles of CTO PCI may improve patient outcomes.

Intravascular imaging guided versus coronary angiography guided percutaneous coronary intervention: systematic review and meta-analysis

ObjectiveTo assess the absolute treatment effects of intravascular imaging guided versus angiography guided percutaneous coronary intervention in patients with coronary artery disease, considering their baseline risk.DesignSystematic review and meta-analysis.Data sourcesPubMed/Medline,...

Intravascular imaging and physiologic assessment in ambiguous coronary lesion.

Intravascular imaging and physiologic assessment in ambiguous coronary lesion.

Retrospective Multicenter Analysis of Intravascular Lithotripsy Use During Calcified Left Main Coronary Artery Percutaneous Coronary Interventions

BackgroundIntravascular lithotripsy (IVL) safely and effectively modifies calcified coronary lesions during percutaneous coronary interventions (PCI). Data regarding its utility in modifying calcified left main coronary artery (LMCA) disease are limited. This study aimed to evaluate short-term outcomes of IVL-assisted LMCA PCI. MethodsThis retrospective multicenter all-comers study analyzed patients who underwent intravascular imaging-guided, IVL-assisted PCI for calcified LMCA disease. Clinical and procedural characteristics were obtained, including intravascular imaging measurements. Technical success was defined as successful stent deployment with <30% residual diameter stenosis. Major adverse cardiac events (MACE) was a composite of all-cause death, myocardial infarction, and target vessel revascularization evaluated immediately postprocedure and at 30-day follow-up. ResultsAmong 184 patients treated at 7 centers from 2019-2023, IVL-assisted LMCA PCI achieved 99.4% technical success. Calcium fracture was identified in 136/165 cases (82.4%) on post-IVL imaging. Pretreatment minimal luminal area increased significantly compared to post-PCI minimal stent area (MSA) (4.1 ± 1.3 to 9.3 ± 2.5 mm2, respectively; P < .001). There was a direct correlation between IVL balloon size and the final MSA (P = .002). In-hospital MACE was 4.4% and 30-day MACE was 8.8%. In multivariate logistic regression, presentation with troponin-positive myocardial infarction was the sole predictor of 30-day MACE. ConclusionsIVL-assisted PCI for calcified LMCA lesions was safe and resulted in high technical success rates, confirming its utility as an effective treatment in this challenging lesion subset.

Calcified coronary left main disease treated with and without intravascular lithotripsy: a real word first description

Abstract Background Intravascular lithotripsy (IVL) is a promising balloon-based technique to treat calcified coronary lesions. The evidence of its use in LM disease is scarce and there are no studies reporting a comparison between IVL and conventional techniques for calcified lesions, especially in LM PCI that represented an exclusion criteria of the DISRUPT-CAD trials. Methods The aim of this study is to evaluate safety and efficacy of IVL to treat moderate-severe calcified LM disease from January 2018 to December 2022. We stratified our cohort into two groups 1) patients who underwent LM PCI with IVL treatment (bail-out or upfront) and 2) LM PCI with conventional techniques excluding IVL (cutting balloons, NC/OPN balloons, rotational atherectomy). Efficacy endpoint: device success and stent expansion evaluated either by intravascular imaging or angiographic criteria. Safety endpoint: peri-procedural complications (coronary dissection, perforation, no-slow flow, peri-procedural MI, pericardial effusion) and in hospital death or target vessel failure. Results 87 patients were enrolled, 43 (49.4%) underwent LM PCI with IVL (group A), while 44 (50.6%) were treated with conventional techniques (35 NC balloons, 7 RA, 2 cutting balloons). Intravascular imaging was performed in 69% of cases, the 2 groups were similar in terms of age (77.4±9.63, p=0.94), comorbidity, clinical presentation and angiographic characteristics. Both groups presented severe calcifications in terms of calcium length (11.9±10.3, p=0.87), arc (270° 144-350, p = 0.76, and thickness (1.3 ±0.7 p =0.99) assessed by intravascular imaging. IVUS calcium score was similar between 2 groups (1.53±0.7, p = 0.7). Target vessel was distal LM-proximal LAD in 56.6%. IVL most used balloon was 3.5mm (55%), followed by 4.00mm (38.2%). Impella CP was implanted to support 4 PCI and removed at the end of the procedure. Provisional stenting was performed in 55.1% of cases, while two-stents technique was used in 26.4% (mainly represented by DK-crush). Good stent expansion (&amp;gt;80%) was achieved in 85% of cases, with a certain prevalence for patients treated with IVL. Optimal stent expansion (&amp;gt;90%) was higher in patients treated with IVL (9 in group A vs 3 in group B), although it did not reach a statistically significative difference (p=0.06). No differences in terms of complications and peri-procedural myocardial infarction occurred between the two groups. Conclusions This is the first description of a comparison between IVL and conventional techniques in LM calcified PCI. IVL appeared to be safe and effective with good stent expansion and low rate of peri-procedural complications and in-hospital MACE. LM lesions treated with IVL appeared to reach greater stent expansion compared to other techniques, although it was not statistically significative. Certainly, further trials are warranted to establish longer term outcomes and the benefit of IVL over existing calcium-modification therapies.

Simultaneous, free-breathing, non-contrast 3D whole-heart coronary magnetic resonance angiography and vulnerable plaque imaging in patients with suspected acute coronary syndrome

Abstract Background Coronary artery high-risk plaque identified on cardiovascular magnetic resonance (CMR) is associated with future coronary events, independent of coronary artery luminal stenosis. We have recently developed a 3-dimensional whole-heart free-breathing non-contrast CMR sequence that allows for simultaneous high-resolution visualisation of the coronary arteries and vulnerable plaque on co-registered bright and black blood images (iT2prep-BOOST) with 100% respiratory scan efficiency. Objectives To validate iT2prep-BOOST in patients with non-ST-segment elevation myocardial infarction (NSTEMI) against the reference standard imaging modalities of invasive X-ray coronary angiography and intravascular imaging [optical coherence tomography (OCT)/intravascular ultrasound (IVUS)]. Methods 41 consecutive patients with suspected NSTEMI, based upon clinical history, electrocardiographic changes and positive high-sensitivity troponin assays, were recruited into the study. Invasive coronary angiography ± intravascular imaging was used to classify coronary segments into the following categories: normal, non-culprit and culprit segments; stenosed segments as well as segments with vulnerable plaque features (lipid, calcium, fibroatheroma, thin cap fibroatheroma (TCFA), plaque rupture and thrombus). The highest plaque/myocardial signal intensity ratio (PMR) in each coronary segment was analysed on iT2prep-BOOST. Results The mean iT2prep-BOOST acquisition time was 10.8 ± 1.3 minutes. The mean ± standard error of mean (SEM) PMR of culprit segments was significantly higher than non-culprit segments, which was significantly higher than normal segments (1.01 ± 0.05 vs. 0.67 ± 0.01 vs. 0.35 ± 0.01, P&amp;lt;0.001). Coronary segments with lipid, calcium and fibroatheroma had a significantly higher PMR compared to normal coronary segments (P&amp;lt;0.001) but lower than segments with TCFA, plaque rupture and thrombus (P&amp;lt;0.001). There was a progressive increase in PMR with increasing degree of coronary stenosis (P&amp;lt;0.001). Patients with type 2 diabetes, hypertension, hyperlipidaemia and family history of coronary artery disease had a significantly higher PMR on iT2prep-BOOST (P&amp;lt;0.001, P=0.02, P=0.04 and P=0.02 respectively). Finally, PMR was positively correlated with HbA1c, total cholesterol, non-HDL cholesterol, LDL cholesterol and triglyceride levels (P&amp;lt;0.001, P=0.02, P=0.02, P=0.05 and P=0.05 respectively). Conclusions In summary, the proposed iT2prep-BOOST framework has the potential to simultaneously acquire coronary artery angiography and to differentiate normal segments from non-culprit and culprit plaque segments. Furthermore, PMR is associated with both biochemical and patient related risk factors for coronary artery disease (CAD). The long-term prognostic value of PMR needs to be investigated in a longitudinal multi-centre study of patients with suspected CAD.Figure 1Figures 2 and 3

Inter-corelab agreement of angiography-derived wall shear stress distribution

Abstract Aims Wall shear stress (WSS) estimated in models reconstructed from intravascular imaging and 3D-quantitative coronary angiography (QCA) data provides important prognostic information and enables the identification of high-risk lesions. However, these analyses are time-consuming and require expertise limiting WSS applications and adoption in clinical practice. Recently, a novel software has been developed for real-time computation of WSS and multidirectional WSS distribution. The aim of this study is to examine its inter-corelab reproducibility. Methods and results Sixty lesions (20 in coronary bifurcations) with a borderline negative fractional flow reserve were selected and processed using the CAAS Workstation WSS prototype (version 6.0 PIE MEDICAL) to estimate WSS and multi-directional WSS. Analysis was performed by two Core laboratories; the estimations of the two corelabs for the WSS in 3 mm segments across each reconstructed vessel were extracted and compared. To examine the concordance between inter-observer analysis of clinically relevant values, the scatterplot was divided into 4 quadrants with AS 61.3% and maximum WSS 8.24 Pa based on the previous publications and Cohen’s Kappa value was presented using these cut-off values. In total 700 segments (256 located in bifurcated vessels) were included in the present analysis. Average analysis time on the software was 219±45s in straight model and 291±61s in bifurcation model. A high intraclass correlation was noted for all the WSS metrics for the estimations of the two core labs irrespective of the presence (range: 0.90 – 0.92) or absence (range: 0.89 - 0.90) of a coronary bifurcation, while the ICC was good-moderate for the multidirectional WSS (range: 0.72-0.86). In addition, the bias between the WSS estimations was low and the limits of agreement were narrow in Bland-Altman analyses (Figure 1). When using the cut-off value of maximum WSS and % AS, a substantial agreement was noted between the two estimations of the two core labs; κ=0.77 for identifying maximum WSS &amp;gt;8.24Pa and κ=0.71 for identifying AS &amp;gt;61.3% (Figure 2). Conclusion The CAAS workstation enables reproducible 3D-QCA reconstruction and computation of WSS metrics. Further research is needed to explore its efficacy in predicting cardiovascular events.Figure 1Figure 2

Twelve-months vessel healing profile following the novel resorbable magnesium scaffold implantation: an intravascular OCT analysis of the BIOMAG-I trial

Abstract Background The first-in-human trial of the latest resorbable magnesium scaffold (RMS), DREAMS 3G, showed favorable clinical and angiographic outcomes up to 6-months. An intravascular optical coherence tomography (OCT) assessment of the vascular healing profile at 6 months and 12 months follow-up may serve as additional supportive evidence for device safety and efficacy. Purpose The aim of this study was to evaluate the vessel healing process by quantifying the presence of strut protrusion (SP) and strut degradation following DREAMS 3G implantation as per intravascular OCT imaging. Methods Patients from the BIOMAG-I trial who underwent OCT imaging at both 6- and 12-months were deemed eligible. This resulted in the inclusion of a total of 51 patients and 52 lesions in the current analysis. The acquired intravascular imaging data were evaluated every 1 mm to visualize and quantify the SP and the number of visible struts at 6- and 12-months. In addition, we investigated the potential impact of SP on mean and minimum lumen area (mm2) at both time point. Results At 12 months, the mean SP area was significantly smaller in comparison to 6 months follow-up (1.87±2.22 mm2 at 6 months vs. 0.99±1.27 mm2 at 12 months, p&amp;lt;0.001). There was a positive correlation between SP area and mean lumen area at both 6 months (p&amp;lt;0.001) and 12 months (p=0.014) follow-up. Similarly, a positive correlation was observed between SP area and minimum lumen area up to 6 months (p=0.006 at 6 months, p=0.323 at 12 months). The number of visible struts was 6.44±7.59 at 6 months and 1.79±0.85 at 12 months (p&amp;lt;0.001). Conclusion The SP area was larger in lesions with greater lumen area following the implantation of the novel RMS. The observed SP area was significantly smaller at 12 months in comparison to 6 months follow-up. These results suggest that the presence of SP is part of a favorable vascular healing process following the treatment with the latest resorbable magnesium scaffold.

Association between high-intensity lipid-lowering therapy and atherosclerotic plaque content changes assed by iMAP-IVUS and near-infrared spectroscopy in patients with premature atherosclerosis

Abstract Background/Introduction The benefits of lipid-lowering drug treatment for the secondary prevention of coronary heart disease have been well-established by randomized, controlled trials. More evidence has now emerged to support the use of high-intensity low-density lipoprotein cholesterol (LDL-C) –lowering therapy including statine, ezetimibe, and PCSK9 inhibitors. Intravascular imaging, such as near-infrared spectroscopy (NIRS) can detect lipid-rich plaques. Virtual histology iMAP-Intravascular ultrasound (iMAP-IVUS) can classify tissue characteristics into 4 major components fibrotic, lipidic, necrotic, and calcified. Purpose Our study aimed to evaluate atherosclerotic plaque composition in very high cardiovascular-risk patients, who received high-intensity lipid-lowering therapy for 15 months. Methods Our study included stable coronary artery disease patients receiving statin and/or ezetimibe in maximum tolerated dose for at least one month, who were scheduled for PCI. In case LDL-C was &amp;gt;1.8 mmol/l, inclisiran was added to the therapy at the time of inclusion and continued for 15 months. The region of interest was a proximal or middle segment with angiographic evidence of nonobstructive de novo atherosclerosis &amp;gt;20% and &amp;lt;50%, evaluated by NIRS and iMAP-IVUS at baseline and 15 months later. After 15 months patients were classified into two groups – those who reached the European Society of Cardiology LDL-C target &amp;lt;1.8 mmol/L and those who did not. Statistical analysis was carried out with SPSS Statistics software, defining a significance level of 0.05. Results 37 eligible patients had undergone IVUS/NIRS investigation. The mean patient age was 53 years. After 15 months the mean LDL-C level decreased from 2.70 mmol/L to 1.79 mmol/l and 25 patients reached a target of &amp;lt;1.8 mmol/L. In the patient group that reached target - 4mm plaque lipid core burden index (LCBImax4mm) decreased from 184.00 (±160.07) to 62.72 (±142.19) with p=0.001 and total LCBI changed from 37.04 (± 40.80) to 15.60 (± 27.87) with p = 0.007. In patients with LDL-C &amp;gt;1.8 mmol/L, LCBImax4mm changed from 211.16 (±167.76) to 125.04 (±152.21) with no statistically significant difference p = 0.074. Similarly, the total LCBI was from 40.33 (± 43.38) to 22.41 (± 24.97) with p = 0.086. In iMAP-IVUS results necro-lipidic core in the &amp;lt;1.8 mmol/L group changed from 78.50 mm3 (±42.77) to 84.77 mm3 (±46.03) p = 0.422. Yet, second group's necro-lipidic core changed from 97.43 mm3 (±58.04) to 89.40 mm3 (±49.03), with no statistically significant difference p = 0.066. Additionally in both groups were significant changes in fibrotic tissues, for the target group from 139.50 mm3 (±69.86) to 147.32 mm3 (±73.56) p = 0.002 and from 149.71 mm3 (±82.79) to 160.09 mm3 (±89.01) p = 0.008 in second group. Conclusion Our study showed that after 15 months of high-intensity lipid-lowering therapy, patients that reached LDL-C levels &amp;lt;1.8 mmol/L, showed lower LCBImax4mm and total LCBI.