Assessment of bioresorbable scaffold with a novel high‐definition 60 MHz IVUS imaging system: Comparison with 40‐MHz IVUS referenced to optical coherence tomography

Adjunctive Utilization of Intravascular Ultrasound in Peripheral Arterial Disease Treatment

BACKGROUND

The utility and benefit of intravascular ultrasound (IVUS) has been well established in coronary interventions, however widespread adoption for peripheral interventions has lagged. The objectives of this review article were to discuss the technical components of IVUS, describe key learning pearls for IVUS utilization, and review the literature describing the clinical outcomes of endovascular peripheral arterial interventions using IVUS.

METHODS

A scoping review of the current literature utilizing Pubmed. Terms used to search the literature included "intravascular ultrasound (IVUS)" in conjunction with "peripheral arterial disease (PAD)," "endovascular interventions," "chronic limb threatening ischemia," "balloon angioplasty" "stenting," "percutaneous coronary intervention," and "outcomes." All types of articles were reviewed including review articles, retrospective reviews, meta-analyses, and prospective observational and randomized studies.

RESULTS

Published literature regarding IVUS use in peripheral arterial interventions is heterogeneous and limited to mainly retrospective studies, registry analyses and metanalyses. Outcomes are generally favorable with the adjunct of IVUS compared to traditional angiography-driven peripheral interventions. The addition of IVUS improves stent expansion, stent patency, and reduces reintervention rates, particularly in infrainguinal arterial lesions. Long-term costs may also be lower with IVUS-guided procedures.

CONCLUSIONS

Expert consensus largely supports the implementation of IVUS in endovascular interventions for peripheral arterial disease. However, more robust high-quality data evaluating the efficacy, durability, and cost of IVUS in peripheral arterial disease are still needed.

CVIT 2023 clinical expert consensus document on intravascular ultrasound

Intravascular ultrasound (IVUS) provides precise anatomic information in coronary arteries including quantitative measurements and morphological assessment. To standardize the IVUS analysis in the current era, this updated expert consensus document summarizes the methods of measurements and assessment of IVUS images and the clinical evidence of IVUS use in percutaneous coronary intervention.

High-definition intravascular ultrasound: current clinical uses

Intravascular ultrasound (IVUS) provides grayscale images of the entire vessel wall, and its technology has recently been improved, resulting in more accurate tissue characterization. Compared with conventional IVUS, high-definition (HD) IVUS provides better resolution, better image quality, faster acquisition and integration of processing tools for more efficient cath lab workflow. HD-IVUS includes transducers with higher frequencies (≥ 45 MHz), allowing a higher near field resolution combined with enough tissue penetration for a more precise assessment of the entire vessel wall. HD-IVUS preserves the potential advantages of conventional (40 MHz) IVUS over optical coherence tomography by adding a substantially higher spatial resolution. For this reason, this technology has generated increasing interest among interventional cardiologists and researchers to provide better detailed morphological evaluation on complicated plaques in acute coronary syndrome patients and better stent optimization. In this review, we provide the state-of-the-art on this technology and its current clinical applications.

Clinical expert consensus document on intravascular ultrasound from the Japanese Association of Cardiovascular Intervention and Therapeutics (2021)

Intravascular ultrasound (IVUS) provides precise anatomic information in coronary arteries including quantitative measurements and morphological assessment. To standardize the IVUS analysis in the current era, this updated expert consensus document summarizes the methods of measurements and assessment of IVUS images and the clinical evidence of IVUS use in percutaneous coronary intervention.

Diagnostic Performance of High-Resolution Intravascular Ultrasound for Abnormal Post-Stent Findings After Stent Implantation - A Comparison Study Between High-Resolution Intravascular Ultrasound and Optical Coherence Tomography

BACKGROUND

High-resolution intravascular ultrasound (HR-IVUS) is the most recently developed IVUS technology, which allows the detailed assessment of intravascular structures. The aim of this study was to evaluate the diagnostic performance of HR-IVUS in the detection of abnormal post-stent findings.Methods and Results:Patients with acute coronary syndrome underwent both HR-IVUS and optical coherence tomography (OCT) for post-stent evaluations. Quantitative measurements for stented segments and qualitative assessments for abnormal post-stent findings (stent edge dissection, intrastent tissue protrusion, and incomplete stent apposition [ISA]) were performed. Forty-seven patients underwent both HR-IVUS and OCT after stent implantation. HR-IVUS identified a larger minimal lumen area and a larger minimal lumen diameter than OCT (6.66±1.98 mm²vs. 5.61±1.79 mm²and 2.87±0.42 mm vs. 2.63±0.43 mm, respectively; both P<0.001). The sensitivity of HR-IVUS for the identification of stent edge dissection, intrastent tissue protrusion, and ISA were 20.0%, 48.9%, and 27.2%, respectively.

CONCLUSIONS

In terms of post-stent evaluation, the diagnostic performance of HR-IVUS remains insufficient. Abnormal post-stent findings might be underestimated when performing HR-IVUS due to its low sensitivity.

Advances in IVUS/OCT and Future Clinical Perspective of Novel Hybrid Catheter System in Coronary Imaging

Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) have been developed and improved as both diagnostic and guidance tools for interventional procedures over the past three decades. IVUS has a resolution of 100 μm with a high tissue penetration and capability of assessing the entire structure of a coronary artery including the external elastic membrane, whereas OCT has a higher resolution of 10–20 μm to assess endoluminal structures with a limited tissue penetration compared to IVUS. Recently, two companies, CONAVI and TERUMO, integrated IVUS and OCT into a single catheter system. With their inherent strength and limitations, the combined IVUS and OCT probes are complementary and work synergistically to enable a comprehensive depiction of coronary artery. In this review, we summarize the performance of the two intracoronary imaging modalities—IVUS and OCT—and discuss the expected potential of the novel hybrid IVUS–OCT catheter system in the clinical field.

A post-market, multi-vessel evaluation of the imaging of peripheral arteries for diagnostic purposeS comparing optical Coherence tomogrApy and iNtravascular ultrasound imaging (SCAN)

Background

Intravascular imaging plays an important part in diagnosis of vascular conditions and providing insight for treatment strategy. Two main imaging modalities are intravascular ultrasound (IVUS) and optical coherence tomography (OCT). The objective of this study was to prove non-inferiority of OCT imaging to IVUS images in matched segments of peripheral vessels in patients with suspected peripheral vascular disease.

Methods

The SCAN study was a prospective, non-inferiority clinical study of matched IVUS and OCT images collected along defined segments of peripheral vessels from twelve subjects (mean age 68 ± 10.3 years; 10 men) displaying symptoms of vascular disease. Luminal diameters were measured by both imaging systems at the distal, middle, and proximal points of the defined segments. Three blinded interventional radiologists evaluated the quality of both imaging modalities in identifying layered structures (3-point grading), plaque (5-point grading), calcification (5-point grading), stent structure (3-point grading), and artifacts (3-point grading) from 240 randomly ordered images. Mean grading scores and luminal diameters were calculated and analyzed with Student’s t-Test and Mann-Whitney-Wilcoxon testing. Intrareader reproducibility was calculated by intraclass correlation (ICC) analysis.

Results

The mean scoring of plaque, calcification, and vascular stent struts by the three readers was significant better in terms of image quality for OCT than IVUS (p < 0.001, p = 0.001, p = 0.004, respectively). The mean scores of vessel wall component visibility and artifacts generated by the two imaging systems were not significantly different (p = 0.19, p = 0.07, respectively). Mean vessel luminal diameter and area at three specific locations within the vessels were not significantly different between the two imaging modalities. No patient injury, adverse effect or device malfunction were noted during the study.

Conclusions

Imaging by OCT provides the physician with better visualization of some vessel and plaque chacteristics, but both IVUS and OCT imaging are safe and effective methods of examining peripheral vessels in order to perform diagnostic assessment of peripheral vessels and provide information necessary for the treatment strategy of peripheral artery disease.

Trial registration

NCT03480685 registered on 29 March 2018.

Diagnostic Performance of High-Resolution Intravascular Ultrasound for the Detection of Plaque Rupture in Patients With Acute Coronary Syndrome

BACKGROUND

The new 60-MHz high-resolution intravascular ultrasound (HR-IVUS) is the next-generation IVUS technology, providing higher image resolution than conventional IVUS. It gives clear images of plaque morphology and can discriminate the underlying mechanism of acute coronary syndrome (ACS). Our study aimed to evaluate the diagnostic performance of 60-MHz HR-IVUS in the detection of plaque rupture in patients with ACS.Methods and Results:Patients with ACS who underwent percutaneous coronary intervention for de novo native coronary artery lesions were enrolled. Both HR-IVUS and optical coherence tomography (OCT) were performed for the culprit lesions prior to interventions other than aspiration thrombectomy. Keeping plaque rupture detected by OCT as the gold standard, the diagnostic performance of HR-IVUS was evaluated. Overall, 70 patients underwent both HR-IVUS and OCT examinations. Of these, imaging assessments by HR-IVUS were available for all 70 patients (100%), and those by OCT were available for 54 patients (77.1%). Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of HR-IVUS for identifying a plaque rupture were 84.8%, 57.1%, 75.7%, 70.6%, and 74.1%, respectively.

CONCLUSIONS

HR-IVUS had high sensitivity, but modest specificity for identifying OCT-derived plaque rupture. Compared with results from previous conventional IVUS studies, HR-IVUS might have increased ability to detect OCT-derived plaque rupture, but there is still substantial scope for improvement, especially in the specificity.

Clinical expert consensus document on standards for measurements and assessment of intravascular ultrasound from the Japanese Association of Cardiovascular Intervention and Therapeutics

Intravascular ultrasound (IVUS) provides precise anatomic information in coronary arteries including quantitative measurements and morphological assessment. To standardize the IVUS analysis in the current era, this expert consensus document summarizes the methods of measurements and assessment of IVUS images.

Direct comparison of optical coherence tomography and high-definition 60-MHz intravascular ultrasound imaging of intra-procedural stent thrombosis in a patient with acute coronary syndrome

An 80-year-old man with ST-segment elevation myocardial infraction underwent coronary stenting using an everolimus-eluting stent, which resulted in a good coronary flow with no residual stenosis. However, 10 min after final coronary angiography, the patient complained of chest discomfort and the ECG again showed ST elevation. Repeat coronary angiography revealed multiple contrast filling defects in the stent. High-definition 60-MHz intravascular ultrasound (IVUS) examination showed multiple low echoic structures inside the stent, though its visualization was not clear. We also conducted optical coherence tomography (OCT) for further investigation, which clearly delineated the outline of the thrombus. An additional balloon dilatation was performed at the site of the stented lesion, and the patient's chest discomfort was relieved, and the ECG was normalized. The clinical implication of this case is that very early phase of intra-stent thrombus is low-density and coarse, and its visualization is better in OCT than in high-definition 60 MHz IVUS.