Role of intravascular ultrasound for the technical assessment of endovascular reconstruction of the aortic bifurcation

OBJECTIVE

The aim of this study was to evaluate the role of intravascular ultrasound (IVUS) for the technical assessment of kissing stents (KSs) and covered endovascular reconstruction of the aortic bifurcation (CERAB) in the treatment of aortoiliac obstructive disease involving the aortic bifurcation.

METHODS

We conducted a single-center retrospective review of patients undergoing endovascular treatment of severe aorto-iliac obstructive disease (2019-2023). IVUS was performed in patients treated by KSs or CERAB according to preoperative indications, in cases of moderate/severe calcifications, mural thrombus, total occlusions, and lesion extension towards the proximity of renal or hypogastric arteries. Indications for IVUS-guided intraoperative revisions were residual stenosis or compression >30%, incomplete stent-to-wall apposition, or flow-limiting dissection at the landing site. Follow-up assessment was performed at 6 and 12 months, and then yearly. Thirty-day outcomes and 2-year patency rates were evaluated. Logistic regression was used to identify factors associated with significant technical defects detected by IVUS needing intraoperative revision.

RESULTS

IVUS was used for the technical assessment of 102 patients treated by KSs (n = 57; 56%) or CERAB (n = 45; 44%) presenting with severe intermittent claudication (39%), rest pain (39%), or ischemic tissue loss (25%). Twenty-nine significant technical defects were identified by IVUS in 25 patients (25%) who then had successful intraoperative correction by additional ballooning (n = 23; 80%) or stenting (n = 6; 20%). Patients with a severely calcified chronic total occlusion (odds ratio, 1.85; 95% confidence interval, 1.01-5.27; P = .044) or severely calcified narrow aortic bifurcation with <12 mm diameter (odds ratio, 2.34; 95% confidence interval, 1.10-8.64; P = .032) were at increased risk for IVUS-guided intraoperative revision. There were no postoperative deaths and no major adverse events. Two-year primary patency was 100%.

CONCLUSIONS

IVUS was used for the technical assessment of KSs/CERAB in a selected cohort of patients with severe aorto-iliac obstructive disease. This allowed the identification and intraoperative correction of a significant technical defect not detected by completion angiogram in one-quarter of patients, achieving optimal 2-year results. IVUS assessment of KSs/CERAB may be considered especially in patients with a calcified total occlusion or narrow aortic bifurcation.

Intravascular ultrasonography assisted carotid artery stenting for treatment of carotid stenosis: Two case reports

BACKGROUND

Digital subtraction angiography (DSA), the gold standard of cerebrovascular disease diagnosis, is limited in its diagnostic ability to evaluate arterial diameter. Intravascular ultrasonography (IVUS) has advantages in assessing stenosis and plaque nature and improves the evaluation and effectiveness of carotid artery stenting (CAS).

CASE SUMMARY

Case 1: A 65-year-old man presented with a five-year history of bilateral lower limb weakness due to stroke. Physical examination showed decreased strength (5-/5) in both lower limbs. Carotid artery ultrasound, magnetic resonance angiography, and computed tomography angiography (CTA) showed a right proximal internal carotid artery (ICA) stenosis (70%-99%), acute cerebral infarction, and severe right ICA stenosis, respectively. We performed IVUS-assisted CAS to measure the stenosis and detected a low-risk plaque at the site of stenosis prior to stent implantation. Post-stent balloon dilatation was performed and postoperative IVUS demonstrated successful expansion and adherence. CTA six months postoperatively showed no significant increase in in-stent stenosis. Case 2: A 36-year-old man was admitted with a right common carotid artery (CCA) dissection detected by ultrasound. Physical examination showed no positive neurological signs. Carotid ultrasound and CTA showed lumen dilation in the proximal CCA with an intima-like structure and bulging in the proximal segment of the right CCA with strip-like low-density shadow (dissection or carotid web). IVUS-assisted DSA confirmed right CCA dissection. CAS was performed and intraoperative IVUS suggested a large residual false lumen. Post-stent balloon dilatation was performed reducing the false lumen. DSA three months postoperatively indicated good stent expansion with mild stenosis.

CONCLUSION

IVUS aids decision-making during CAS by accurately assessing carotid artery wall lesions and plaque nature preoperatively, dissection and stenosis morphology intraoperatively, and visualizing and confirming CAS postoperatively.

Human Basilar Arterial Plaque Detected by Near-Infrared Spectroscopy: Clinical Image

A patient in their 70s presented with weakness of the left limb and aphasia. Left vertebral angiography showed acute basilar artery occlusion. After mechanical thrombectomy, basilar artery trunk stenosis was evident and catheter-based near-infrared spectroscopy (NIRS) showed lipid-rich atherosclerotic plaque extending to almost 220° of the vessel circumference in the culprit lesion. Loading doses of dual antiplatelet therapy and aggressive medical treatment were started because additional intervention might have increased risk of plaque protrusion and thrombotic reocclusion. The patient presented with minor stroke caused by restenosis of the basilar artery 4 months later; balloon angioplasty and stenting were performed without thromboembolic complications. The patient was discharged without any new neurologic deficits. NIRS visualizes the distribution of lipids in the culprit lesion and the plaque burden of residual stenosis, identifies mechanisms of in situ thrombosis, and provides suggestions for the timing of additional interventions.

Revascularization Options for Left Main Disease: What Clinicians Need to Know

PURPOSE OF REVIEW

Left main disease represents the highest-risk lesion subset of coronary artery disease and is associated with adverse cardiovascular events. Accordingly, we aim to understand how the significance of left main disease is assessed by different modalities, followed by a review of management options in current era.

RECENT FINDINGS

Invasive coronary angiogram remains the gold standard for assessment of left main disease, but intracoronary imaging or physiological testing is indicated for angiographically equivocal disease. Revascularization by either coronary artery bypass surgery or percutaneous coronary intervention is strongly recommended, which have been compared by six randomized trials, as well as recent meta-analyses. Surgical revascularization remains the preferred mode of revascularization, especially in patients with high lesion complexity and left ventricular dysfunction. Randomized studies are needed to understand if current-generation stents with the use of intracoronary imaging and improved medical therapy could match outcomes with surgical revascularization.

Fenestration using a novel cutting balloon for acute vessel occlusion secondary to intramural hematoma following stent implantation

Intramural hematoma after percutaneous coronary angioplasty is associated with adverse events and requires immediate bail out; however, the optimal treatment approach has not yet been established. Herein, we describe a case of coronary occlusion due to an intramural hematoma following stent implantation in the mid left anterior descending (LAD) coronary artery. Intravascular ultrasound revealed a massive intramural hematoma from the distal edge of the stent to the distal segment of the LAD, and the true lumen was completely compressed. By performing fenestration with a Wolverine™ Cutting Balloon™ (Boston Scientific, Massachusetts, United States), we were able to bail out without additional stenting. In conclusion, a cutting balloon with improved crossability can be an effective management strategy for intramural hematoma.

Role of IVUS in the rectification of angiographically judged ramus intermedius and its clinical significance

Background

Due to the technical limitations of coronary artery angiography (CAG), ramus intermedius (RI) is sometimes difficult to distinguish from a high-origin obtuse marginal branch or a high-origin diagonal branch. This study sought to investigate the role of intravascular ultrasonography (IVUS) in the rectification of angiographically judged RI.

Methods

This study retrospectively analyzed 165 patients who were reported to have an RI based on CAG and underwent IVUS implementation from 02/01/2009 to 31/12/2019 in Zhongshan Hospital, Fudan University. Taking IVUS as the gold standard, we calculated the accuracy of RI identification by CAG and evaluated the impact of RI on revascularization strategy.

Results

Among the 165 patients, 89 patients (54%) were demonstrated to have an RI on IVUS (IVUS-RI), 32 patients (19%) were identified to have a high-origin diagonal branch on IVUS (IVUS-h-D), and 44 patients (27%) had an actual high-origin obtuse marginal artery on IVUS (IVUS-h-OM). Among 84 patients who underwent one-stent crossover stenting because of left main furcation lesions (48 patients in the IVUS-RI group, 12 patients in the IVUS-h-D group, and 24 in the IVUS-h-OM group), 14.6% of patients in the IVUS-RI group, 33.3% in the IVUS-h-D group and 0% in the IVUS-h-OM group had CAG-RI compromise (P = 0.02), which was defined as severe stenosis of the RI ostium (> 75%) or significant RI flow impairment (TIMI < 3).

Conclusions

Only 54% of CAG-RIs were confirmed by IVUS, which indicates the necessity of preintervention IVUS to distinguish real RIs from other branches in LM furcation lesions.

Long-Term Clinical Outcomes After Filter Protection During Percutaneous Coronary Intervention in Patients With Attenuated Plaque - 1-Year Follow up of the VAMPIRE 3 (Vacuum Aspiration Thrombus Reemoval 3) Trial

BACKGROUND

Selective use of distal filter protection during percutaneous coronary intervention (PCI) for acute coronary syndromes (ACS) decreased the incidence of no-reflow phenomena and in-hospital serious adverse cardiac events compared with conventional PCI in patients with attenuated plaque ≥5 mm; however, its long-term clinical outcome remains unknown.Methods and Results:Patients who had ACS with attenuated plaque ≥5 mm were assigned to receive distal protection (DP) (n=98) or conventional treatment (CT) (n=96). The rate of major adverse cardiovascular events (MACE), a composite of death from any cause, non-fatal myocardial infarction, or target vessel revascularization (TVR) at 1 year, was the pre-specified secondary endpoint of the trial. MACE at 1 year occurred in 12 patients (12.2%) in the DP group and 3 patients (3.1%) in the CT group (P=0.029), which was driven by a higher risk of TVR (11 [11.2%] vs. 2 [2.1%], P=0.018). In patients treated with bare-metal stents (n=42), MACE occurred in 25.0% of the patients in the DP group and in none of the patients in the CT group (P=0.029), whereas in patients treated with drug-eluting stents (n=151), rates of MACE were similar in the groups (8.1% vs. 3.9%, P=0.32).

CONCLUSIONS

In ACS patients with attenuated plaque ≥5 mm, the 1-year rates of MACE were higher in the DP group than in the CT group. This effect might be mitigated by the use of drug-eluting stents.

Iliocaval outflow obstruction in patients with venous ulcers in a small comparison study between patients with primary varicose veins and chronic deep vein disease

OBJECTIVE

Iliocaval outflow obstruction was investigated in patients with venous ulcers caused by primary superficial disease and chronic deep vein disease METHODS: After clinical assessment, patients with healed or active venous leg ulcers underwent lower extremity duplex ultrasound examination to identify the presence of venous disease in the superficial, deep and perforating systems. Bilateral contrast venography and intravascular ultrasound examination were then performed to determine the presence and degree of iliocaval obstructive lesions.

RESULTS

This retrospective study included a total of 59 patients with 71 legs presenting active or healed ulcer. There were 16 limbs (22.5%) with superficial venous reflux associated with normal infrainguinal deep veins (group I) and 55 limbs (77.5%) with infrainguinal post-thrombotic deep venous disease (group II). Using venography and intravascular ultrasound examination, the incidence of >50% of venous obstruction in the iliocaval system in groups I and II were 75% and 83.6%, respectively. All obstructive lesions in group I were nonthrombotic. However, group II included thrombotic, nonthrombotic and combinations of the two types of obstructions. Group II had more ulcers (1.73 ± 1.3 vs 1.17 ± 0.5; P = .03), larger ulcers (>6 cm in 34.1% vs 8.3%), longer duration of ulcers (71.3 ± 110.5 months vs 37.9 ± 40.4 months; P = .03), smaller diameter of refluxing superficial veins (7.7 ± 2.6 mm vs 15.1 ± 6.6 mm; P = .001), and higher incidence of occluded iliocaval systems (18 [32.7%] vs 0; P = .003) than group I. After the exclusion of bilateral cases and thrombotic obstructions, the incidence of >50% nonthrombotic obstruction in ipsilateral and contralateral sides was 76.5% and 24.4%, respectively (P = .003).

CONCLUSIONS

The results of this study revealed that the majority of patients with venous ulcers with either infrainguinal primary superficial or post-thrombotic deep venous disease had an element of iliocaval venous obstruction.

Zero-Contrast Intravascular Lithotripsy Angioplasty Facilitated by Intravascular Ultrasound

A 49-year-old female with severe kidney dysfunction presented with an acute coronary syndrome. After angiography demonstrated severe disease in the left anterior descending and obtuse marginal arteries, she underwent staged percutaneous intervention with intravascular lithotripsy under fluoroscopic and intravascular ultrasound guidance with the use of zero contrast. She did well and went home 3 days post procedure with no deterioration in her renal function. This demonstrates the feasibility of complex coronary intervention with no contrast requirement.

Ten-year clinical outcomes of an intermediate coronary lesion; prognosis and predictors of major adverse cardiovascular events

AIMS

The natural history of intermediate coronary lesions (30 to 70% angiographic stenosis) and the prognostic predictors in predicting very long-term clinical outcomes is unknown.

METHODS

Patients (n = 82, mean 60 years old) with intermediate non-culprit coronary lesions (NCL, n = 86), evaluated by virtual histology-intravascular ultrasound (VH-IVUS), were followed for 10 years. Major adverse cardiovascular events (MACE; all-cause death, myocardial infarction, stroke, and revascularization) were collected over follow-up period and stratified by culprit lesion (CL)-related, NCL-related and indeterminate/unrelated to CL or NCL lesions. NCL-related MACE was further stratified into intermediate and minimal NCL-related events.

RESULTS

Twenty two (25.6%) out of 86 intermediate NCL were associated with MACE in 20/82 (24.4%) study patients. Ten-year cumulative intermediate NCL-related MACE rate was twice (25.6% vs. 12.8%) compared to treated culprit lesion (CL)-related MACE. Ten-year cumulative revascularization rate of the intermediate NCL lesions was similar (17.4% vs. 15.1%) to those of CL, but higher than that of minimal (stenosed <30% at baseline) NCL (8.1%). Important intermediate NCL VH-IVUS predictor for MACE was area stenosis ≥50%, and for revascularization were percent diameter stenosis, plaque burden ≥70%, and fibrofatty area.

CONCLUSIONS

Ten-year MACE rate of intermediate NCL was double that of CL and ten-year revascularization rate of intermediate NCL was similar or slightly higher than that of CL. VH-IVUS may play an important role in determining the very long-term clinical outcomes in patients with intermediate NCL. This study suggests that Intermediate NCL can be safely followed up in terms of revascularization risk.

Ischemia-based Coronary Revascularization: Beyond Anatomy and Fractional Flow Reserve

Treatment strategies for patients with coronary artery disease (CAD) should be based on objective evidence of inducible ischemia in the subtended myocardium to improve clinical outcomes, symptoms, and cost-effectiveness. Fractional flow reserve (FFR) is the most verified index to-date for invasively evaluating lesion-specific myocardial ischemia. Favorable results from large clinical trials that applied FFR-guided percutaneous coronary intervention (PCI) prompted changes in coronary revascularization guidelines to emphasize the importance of this ischemia-based strategy using invasive coronary physiology. However, the frequency of functional evaluations is lacking in daily practice, and visual assessment still dominates treatment decisions in CAD patients. Despite recent efforts to integrate functional and anatomical assessments for coronary stenosis, there is considerable discordance between the 2 modalities, and the diagnostic accuracy of simple parameters obtained from current imaging tools is not satisfactory to determine functional significance. Although evidence that supports or justifies anatomy-guided PCI is more limited, and FFR-guided PCI is currently recommended, it is important to be aware of conditions and factors that influence FFR for accurate interpretation and application. In this article, we review the limitations of the current anatomy-derived evaluation of the functional significance of coronary stenosis, detail considerations for the clinical utility of FFR, and discuss the importance of an integrated physiologic approach to determine treatment strategies for CAD patients.

Intracoronary Imaging in the Detection of Vulnerable Plaques

Coronary artery disease is the result of atherosclerotic changes to the coronary arterial wall, comprising endothelial dysfunction, vascular inflammation and deposition of lipid-rich macrophage foam cells. Certain high-risk atherosclerotic plaques are vulnerable to disruption, leading to rupture, thrombosis and the clinical sequelae of acute coronary syndrome. Though recognised as the gold standard for evaluating the presence, distribution and severity of atherosclerotic lesions, invasive coronary angiography is incapable of identifying non-stenotic, vulnerable plaques that are responsible for adverse cardiovascular events. The recognition of such limitations has impelled the development of intracoronary imaging technologies, including intravascular ultrasound, optical coherence tomography and near-infrared spectroscopy, which enable the detailed evaluation of the coronary wall and atherosclerotic plaques in clinical practice. This review discusses the present status of invasive imaging technologies; summarises up-to-date, evidence-based clinical guidelines; and addresses questions that remain unanswered with regard to the future of intracoronary plaque imaging.

Haptoglobin polymorphism in relation to coronary plaque characteristics on radiofrequency intravascular ultrasound and near-infrared spectroscopy in patients with coronary artery disease

BACKGROUND

Conflicting results exist regarding the association between a common Haptoglobin (Hp) polymorphism and risk of coronary artery disease. We investigated the association of three functionally different anti-oxidant and anti-inflammatory Hp phenotypes (Hp1-1, Hp2-1, Hp2-2) with invasively measured degree and composition of coronary atherosclerosis as determined by intravascular ultrasound (-virtual histology) (IVUS(-VH)) as well as near-infrared spectroscopy (NIRS).

METHODS

Non-culprit coronary artery segments of 581 patients with acute coronary syndrome (ACS) or stable angina pectoris were imaged with IVUS(-VH). In 203 patients, the segments were also imaged with NIRS. Pre-procedural blood samples were drawn for Hp phenotyping. Degree (segment plaque volume, segment plaque burden (PB); presence of lesions with PB≥70%) and composition (segment fractions of fibrous, fibro-fatty, dense calcium, and necrotic core tissue; presence of IVUS-VH derived thin-cap fibroatheroma lesions) of coronary atherosclerosis were measured.

RESULTS

No differences were present between the three Hp phenotypes with regard to degree and composition of coronary atherosclerosis in the full cohort. However, ACS patients with a Hp2-1 or Hp2-2 phenotype had a higher segment PB percentage (β[95% CI]: 3.88[0.31-7.44], p=0.033), increased prevalence of lesions with PB≥70% (OR[95% CI]: 3.61[1.06-12.30], p=0.040), and a tendency towards a higher segment plaque volume (β[95% CI]: 1.29[-0.04-2.62], p=0.056) in multivariable analyses.

CONCLUSIONS

Although in the full cohort no associations could be demonstrated between Hp phenotypes and plaque characteristics, a significant association was present between phenotypes resulting from a genotype containing a Hp2 allele (Hp2-1 or Hp2-2) and a higher degree of atherosclerosis in patients with ACS.

Diagnostic Performance of Intravascular Ultrasound-Derived Minimal Lumen Area to Predict Functionally Significant Non-Left Main Coronary Artery Disease: a Meta-Analysis

BACKGROUND AND OBJECTIVES

Intravascular ultrasound (IVUS)-guided percutaneous coronary intervention frequently results in unnecessary stenting due to the low positive predictive value of IVUS-derived minimal lumen area (MLA) for identification of functionally significant coronary stenosis. We appraised the diagnostic accuracy of IVUS-derived MLA compared with the fractional flow reserve (FFR) to assess intermediate coronary stenosis.

SUBJECTS AND METHODS

We searched MEDLINE and Cochrane databases for studies using IVUS and FFR methods to establish the best MLA cut-off values to predict significant non-left main coronary artery stenosis. Summary estimates were obtained using a random-effects model.

RESULTS

The 17 studies used in our analysis enrolled 3920 patients with 4267 lesions. The weighted overall mean MLA cut-off value was 2.58 mm². The pooled MLA sensitivity that predicted functionally significant coronary stenosis was 0.75 (confidence interval [CI]: 0.72 to 0.77) and the specificity was 0.66 (CI: 0.64 to 0.68). The positive likelihood ratio (LR) was 2.33 (CI: 2.06 to 2.63) and LR (-) was 0.33 (CI: 0.26 to 0.42). The pooled diagnostic odds ratio (DOR) was 7.53 (CI: 5.26 to 10.76) and the area under the summary receiver operating characteristic curve for all the trials was 0.782 with a Q point of 0.720. Meta-regression analysis demonstrated that an FFR cut-off point of 0.75 was associated with a four times higher diagnostic accuracy compared to that of 0.80 (relative DOR: 3.92; 95% CI: 1.25 to 12.34).

CONCLUSION

IVUS-derived MLA has limited diagnostic accuracy and needs careful interpretation to correlate with functionally significant non-left main coronary artery stenosis.

Intravascular ultrasound for morphological assessment of napkin-ring sign detected on multidetector computed tomography

BACKGROUND

Although napkin-ring sign (NRS) plaques assessed by multidetector computed tomography (MDCT) is identified as a high-risk feature, the detailed morphological features are still unknown. The purpose of this study was to elucidate the morphological features of the MDCT-assessed NRS using intravascular ultrasound (IVUS).

METHODS

We evaluated 204 plaques in 193 patients with non-ST-elevation acute coronary syndrome who were diagnosed using 128-slice MDCT and were assessed using IVUS prior to coronary intervention. Morphology was compared between plaques with and without MDCT-assessed NRS. Severe IVUS-assessed attenuation was defined as an attenuation angle >180°.

RESULTS

NRS was detected in 49 lesions. MDCT-assessed plaque attenuation was lower (p<0.0001), and cross-sectional plaque areas at lesion sites, remodeling index, and the prevalence of positive remodeling were greater, in lesions with NRS (p<0.005, p<0.0001, and p<0.0001, respectively). Furthermore, the IVUS-assessed remodeling index and prevalence of severe attenuation and speckled echo appearance were significantly greater in lesions with NRS (p<0.01, p<0.0001, and p<0.0001, respectively). Using multivariate analysis, IVUS-assessed speckled echo appearance was identified as an independent predictor of MDCT-assessed NRS (odds ratio, 3.59; 95% confidence interval, 1.49-8.66; p<0.005).

CONCLUSION

MDCT assessment of NRS may be associated with larger heterogeneous necrotic cores and greater positive remodeling.

Imaging- and physiology-guided percutaneous coronary intervention without contrast administration in advanced renal failure: a feasibility, safety, and outcome study

AIMS

The feasibility, safety, and clinical utility of percutaneous coronary intervention (PCI) without radio-contrast medium in patients with advanced chronic kidney disease (CKD) are unknown. In this series, we investigated a specific strategy for 'zero contrast' PCI with the aims of preserving renal function and preventing the need for renal replacement therapy (RRT) in patients with advanced CKD.

METHODS AND RESULTS

A total of 31 patients with advanced CKD [creatinine = 4.2 mg/dL, inter-quartile range (IQR) 3.1-4.8, estimated glomerular filtration rate = 16 ± 8 mL/min/1.73 m²] who had clinical indication for PCI based on a prior minimal contrast coronary angiogram were included. Zero contrast PCI was performed at least 1 week after diagnostic angiography using real-time intravascular ultrasound (IVUS) guidance, with pre- and post-PCI measurements of fractional flow reserve and coronary flow reserve to confirm physiological improvement. This approach resulted in successful PCI, no major adverse cardiovascular events and preservation of renal function without the need for RRT within a follow-up time of 79 days (IQR 33-207) in all patients.

CONCLUSION

In patients with advanced CKD who require revascularization, PCI may safely be performed without contrast using IVUS and physiological guidance with high procedural success and without complications.

Analysis of Plaque Composition in Coronary Chronic Total Occlusion Lesion Using Virtual Histology-Intravascular Ultrasound

Background and Objectives

Success rates of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) have recently been reported to range from 80% to 90%. A better understanding of the pathologic characteristics of the CTO lesion may helpful to improving CTO PCI success rates. We evaluated the CTO lesion in patients with stable angina (SA) by virtual histology-intravascular ultrasound (VH-IVUS).

Subjects and Methods

The study population consisted of 149 consecutive patients with SA underwent VH-IVUS examination. We analyzed demographic and VH-IVUS findings in 22 CTO patients (17 males; mean, 62.3 years old) compared with 127 non-CTO patients (82 males; mean, 61.3 years old).

Results

A significantly lower ejection fraction (57.6±13.0% vs. 65.4±8.8%, p=0.007) was detected in the CTO group compared with the non-CTO group. Reference vessel lumen area of the proximal and distal segment was significantly less in CTO group than in non-CTO group. The lesion length of the CTO group was significantly longer than those of the non-CTO group (24.4±9.6 mm vs. 17.2±7.4 mm, p<0.001). Total atheroma volume (224±159 mm³ vs. 143±86 mm³, p=0.006) and percent atheroma volume (63.2±9.6% vs. 55.8±8.5%, p=0.011) of the CTO group were also significantly greater than those of non-CTO group. However, the lesion length adjusted plaque composition of the CTO group was not significantly different compared with that of the non-CTO group.

Conclusion

CTO lesions had a longer lesion length and greater plaque burden than the non-CTO lesion in patients with SA. However, lesion length adjusted plaque composition showed similar between the two groups. These results support that plaque characteristics of CTO lesions are similar to non-CTO lesions in patients with SA.

Invasive testing for coronary artery disease: FFR, IVUS, OCT, NIRS

Coronary angiography is the gold standard for the diagnosis of coronary artery disease and guides revascularization strategies. The emergence of new diagnostic modalities has provided clinicians with adjunctive physiologic and image-based data to help formulate treatment strategies. Fractional flow reserve can predict whether percutaneous intervention will benefit a patient. Intravascular ultrasonography and optical coherence tomography are intracoronary imaging modalities that facilitate the anatomic visualization of the vessel lumen and characterize plaques. Near-infrared spectroscopy can characterize plaque composition and potentially provide valuable prognostic information. This article reviews the indications, basic technology, and supporting clinical studies for these modalities.

Clinical Outcomes in Patients with Intermediate Coronary Stenoses: MINIATURE Investigators (Korea MultIceNter TrIal on Long-Term Clinical Outcome According to the Plaque Burden and Treatment Strategy in Lesions with MinimUm Lumen ARea lEss Than 4 mm(2) Using Intravascular Ultrasound)

Background and Objectives

We evaluated the two-year clinical outcomes in patients with angiographically intermediate lesions according to the plaque burden and treatment strategy.

Subjects and Methods

We prospectively enrolled patients with angiographically intermediate lesions (diameter stenosis 30-70%) with an intravascular ultrasound (IVUS) minimum lumen area (MLA) <4 mm² with 50-70% plaque burden of 16 Korean percutaneous coronary intervention centers. Patients were divided into medical therapy group (n=85) and zotarolimus-eluting stent group (ZES; Resolute) group (n=74). We evaluated the incidences of two-year major adverse cardiovascular events (MACE).

Results

A two-year clinical follow-up was completed in 143 patients and MACE occurred in 12 patients. There were no significant differences in the incidences of death (1.3% vs. 3.0%, p=0.471), target vessel-related non-fatal myocardial infarction (0.0% vs. 0.0%, p=1.000) and target vessel revascularizations (7.8% vs. 4.5%, p=0.425) between medical and ZES groups. Independent predictors of two-year MACE included acute myocardial infarction {odds ratio (OR)=2.87; 95% confidence interval (CI) 1.43-6.12, p=0.014}, diabetes mellitus (OR=2.46; 95% CI 1.24-5.56, p=0.028) and non-statin therapy (OR=2.32; 95% CI 1.18-5.24, p=0.034).

Conclusion

Medical therapy shows comparable results with ZES, and myocardial infarction, diabetes mellitus and non-statin therapy were associated with the occurrence of two-year MACE in patients with intermediate lesion with IVUS MLA <4 mm² with 50-70% of plaque burden.

Impact of Intravascular Ultrasound in Clinical Practice

Intravascular ultrasound (IVUS) has expanded our understanding of atherosclerotic plaque morphology, and provides an opportunity to guide cardiovascular interventions and evaluate results. Use of this technique requires understanding of ultrasound physics, catheter differences, skills in vessel, plaque and stent quantification and knowledge of artifacts and various physiologic and pathologic findings. Optimal cardiovascular interventions should result in absence of inflow or outflow obstruction, precise geographic landing, while attaining the largest feasible luminal gain without plaque protrusion, vessel dissection or perforation and, if deployed, with complete stent expansion and apposition to the vessel wall. IVUS is safe, cost efficient and effectively optimises cardiovascular interventions. In addition, IVUS improves outcomes when used to guide coronary interventions using bare metal stents (BMS) and drug eluting stents (DES). The role of IVUS in endovascular therapy is rapidly expanding. This review will focus on the impact of IVUS in clinical practice.

Impact of plaque composition on long-term clinical outcomes in patients with coronary artery occlusive disease

BACKGROUND AND OBJECTIVES

It is unclear which plaque component is related with long-term clinical outcomes in patients with coronary artery occlusive disease (CAOD). We assessed the relationship between plaque compositions and long-term clinical outcomes in those patients.

SUBJECTS AND METHODS

The study subjects consisted of 339 consecutive patients (mean 61.7±12.2 years old, 239 males) who underwent coronary angiogram and a virtual histology-intravascular ultrasound examination. Major adverse cardiac and cerebrovascular events (MACCE), including all-cause death, non-fatal myocardial infarction, cerebrovascular events, and target vessel revascularization were evaluated during a mean 28-month follow-up period.

RESULTS

Patients with high fibrofatty volume (FFV, >8.90 mm(3), n=169) had a higher incidence of MACCE (25.4% vs. 14.7%, p=0.015), male sex (75.7% vs. 65.3%, p=0.043), acute coronary syndrome (53.3% vs. 35.9%, p=0.002), multivessel disease (62.7% vs. 41.8%, p<0.001) and post-stent slow flow (10.7% vs. 2.4%, p=0.002) than those with low FFV (FFV≤8.90 mm(3), n=170). Other plaque composition factors such as fibrous area/volume, dense calcified area/volume, and necrotic core area/volume did not show any impact on MACCE. Cardiogenic shock {hazard ratio (HR)=8.44; 95% confidence interval (CI)=3.00-23.79; p<0.001} and FFV (HR=1.85; 95% CI=1.12-3.07; p=0.016) were the independent predictors of MACCE by Cox regression analysis. Thin-cap fibroatheroma, necrotic core area, and necrotic core volume were not associated with MACCE.

CONCLUSION

FFV of a culprit lesion was associated with unfavorable long-term clinical outcomes in patients with CAOD.

Intravascular ultrasound-guided percutaneous coronary intervention improves the clinical outcome in patients undergoing multiple overlapping drug-eluting stents implantation

BACKGROUND AND OBJECTIVES

Stented segment length is a predictive factor for restenosis and stent thrombosis still in the drug-eluting stent (DES) era, and the benefit of routine intravascular ultrasound (IVUS) is still unclear. The aim of the present study was to investigate whether IVUS-guided percutaneous coronary intervention (PCI) improved the vascular outcomes as compared with conventional PCI in the treatment of diffuse coronary artery disease.

SUBJECTS AND METHODS

From our registry database from January 2006 to May 2009, we identified 85 consecutive patients with de novo coronary lesions treated with at least 64 mm of multiple, overlapping DES. The 2-year rate of major adverse cardiovascular events (MACE), defined as the composite of cardiovascular death, non-fatal myocardial infarction, target lesion revascularization (TLR), or stent thrombosis, was compared according to the use of IVUS.

RESULTS

The 2-year MACE rate was lower in the IVUS-guided group than that of the angiography-guided group (8% vs. 33.3%, p=0.005). The incidence of TLR was lower in patients with IVUS use than in those without IVUS use (0% vs. 27.8%, p<0.001). On Cox proportional hazard analysis, no IVUS use {hazard ratio (HR) 5.917, 95% confidence interval (CI) 1.037-33.770, p=0.045} and age (HR 1.097, 95% CI 1.006-1.138, p=0.032) were unfavorable predictors for the 2-year MACE.

CONCLUSION

The use of IVUS may improve the effectiveness and safety of multiple overlapping drug-eluting stenting for long, diffuse coronary lesions.

Utility of optical coherence tomography to assess a hazy intracoronary image after percutaneous coronary intervention

Although its use in daily practice is not common, optical coherence tomography (OCT) is a powerful research tool in invasive cardiology. This report describes a hazy angiography image after percutaneous coronary intervention that has been assessed using OCT. Based on the results of the OCT, the patient underwent an elective coronary angioplasty with standard anticoagulation. After implantation of the stent, an intracoronary hazy image was seen on angiography. The use of OCT permitted a correct diagnosis and a successful treatment. This paper provides a discussion of the advantages and disadvantages of OCT, and a comparison with intravascular ultrasound.

Positive Vascular Remodeling in Culprit Coronary Lesion is Associated With Plaque Composition: An Intravascular Ultrasound-Virtual Histology Study

BACKGROUND AND OBJECTIVES

The relationship between the positive remodeling (PR) of a coronary artery and plaque composition has been studied only in a relatively small number of study population or non-culprit lesion. We evaluated the association between coronary plaque composition and coronary artery remodeling in a relatively large number of culprit lesions.

SUBJECTS AND METHODS

The study population consisted of 325 consecutive patients with coronary artery disease that underwent intravascular ultrasound-virtual histology examination in a culprit lesion. The remodeling index (RI) was calculated as the lesion external elastic membrane (EEM) area divided by the average reference EEM area.

RESULTS

The lesions with PR (RI>1.05, n=97, mean RI=1.19±0.12) had a higher fibrous volume/lesion length (3.85±2.12 mm(3)/mm vs. 3.04±1.79 mm(3)/mm, p=0.003) and necrotic core volume/lesion length (1.26±0.89 mm(3)/mm vs. 0.90±0.66 mm(3)/mm, p=0.001) than those with negative remodeling (NR) (RI<0.95, n=132, mean RI=0.82±0.09). At the minimal luminal area site, the lesions with PR had a higher fibrous area (5.81±3.17 mm(2) vs. 3.61±2.30 mm(2), p<0.001), dense calcified area (0.73±0.69 mm(2) vs. 0.46±0.43 mm(2), p=0.001), and necrotic core area (1.93±1.33 mm(2) vs. 1.06±0.91 mm(2), p<0.001) than those with NR. RI showed significant positive correlation with fibrous volume/lesion length (r=0.173, p=0.002), necrotic core volume/lesion length (r=0.188, p=0.001), fibrous area (r=0.347, p<0.001), fibrofatty area (r=0.111, p=0.036), dense calcified area (r=0.239, p<0.001), and necrotic core area (r=0.334, p<0.001). Multivariate analysis showed that the independent factor for PR was the necrotic core volume/lesion length (beta=0.130, 95% confidence interval; 0.002-0.056, p=0.037) over the entire lesion.

CONCLUSION

This study suggests that PR in a culprit lesion is associated with the necrotic core volume in the entire lesion, which is a characteristic of vulnerable plaque.

Fibro-Fatty Component is Important for the Long-Term Clinical Events in Patients Who Have Undergone Primary Percutaneous Coronary Intervention

Background and Objectives

We evaluated which plaque components are associated with long-term clinical events in patients who underwent primary percutaneous coronary intervention (PCI).

Subjects and Methods

The study subjects consisted of 57 consecutive patients (mean age, 58.5±14.5 years; 45 males) who underwent primary PCI and a virtual histology-intravascular ultrasound examination. Major adverse cardiac events (MACEs) including death, acute myocardial infarction, stroke, and revascularization were evaluated during the mean 28 month follow-up period.

Results

Patients with high fibro-fatty volume (FFV >13.4 mm³, n=29; mean age, 61.3 years) had a lower ejection fraction (52.7% vs. 59.4%, p=0.022), a higher incidence of multi-vessel disease (69.0% vs. 28.6%, p=0.002), larger plaque area (25.7 mm² vs. 15.9 mm², p<0.001), and larger plaque volume (315 mm³ vs. 142 mm³, p<0.001) than those with a low FFV (≤13.4 mm³, n=28; mean age, 55.6 years). Patients with high FFV had a significantly higher incidence (32.1% vs. 8.3%, p=0.036) of MACE than those with low FFV. When we divided the study population according to the necrotic core volume (NCV), fibrous volume, or dense calcified volume, no significant findings in terms of demographics and MACE rates were observed. A Cox regression analysis revealed that the independent factor for MACE was FFV (hazard ratio, 6.748; 95% confidence interval, 1.168-38.971, p=0.033) in this study population.

Conclusion

The coronary plaque component, particularly FFV, but not NCV, was important in long-term clinical outcomes in patients who underwent primary PCI.

The effects of statin and niacin on plaque stability, plaque regression, inflammation and oxidative stress in patients with mild to moderate coronary artery stenosis

Background and Objectives

The aim of this study was to compare the effects of a combination of niacin and simvastatin to simvastatin alone, on plaque regression and inflammatory makers.

Subjects and Methods

The study had a prospective, randomized design. Subjects were patients with intermediate coronary artery stenosis. A total of 28 patients received a combination of niacin 1,000 mg plus simvastatin 40 mg (N+S group, n=14); the other group received simvastatin 40 mg alone (S group, n=14). All patients had a baseline and a 9-month follow-up coronary angiogram and an intravascular ultrasound procedure. Parameters such as normalized total atheroma volume (nTAV) and percent atheroma volume (PAV) were analyzed before and after treatment as were inflammatory markers such as high sensitivity C-reactive protein (hs-CRP), Matrix me-talloproteinase-9 (MMP-9) and soluble CD40 ligand (sCD40L).

Results

There was no difference in baseline characteristics between the two groups. The nTAV and PAV in the N+S group before and after treatment were not different than those in the S group. But the degree of changes (delta) in nTAV in the N+S group was greater than that in the S group (-21.6±10.68 vs. 5.25±42.19, respectively, p=0.024). Also, the change in PAV in the NS group was higher than that in the S group (-1.2±2.5 vs. -0.6±5, respectively, p=0.047. Changes in hs-CRP, MMP-9, and sCD40L in the NS group were significantly greater than those of the S group (-0.71±1.25, 73.5±64.9, -1,970±1,925 vs. -0.32±0.96, 62.5±30.6, -1,673±2,628, respectively).

Conclusion

The combination of niacin plus simvastatin decreases coronary plaque volume and attenuates the inflammatory response in patients with intermediate coronary artery stenosis.

Recanalization of an accidentally crushed coronary stent by intravascular ultrasonography catheter entrapment

Intravascular ultrasonography (IVUS) imaging is a user-friendly technique widely used during coronary interventions. An 80-year-old man was admitted with chest pain, and successful percutaneous coronary intervention was performed with stent implantation. One week later, the patient complained of further chest pain. Urgent coronary angiography showed total occlusion of the middle left anterior descending artery and the aspiration of thrombi was high. IVUS imaging showed inadequate stent strut apposition and distal dissection. We attempted another stent implantation but the IVUS catheter was stuck on the 0.014 inch wire. Therefore, we tried to pass the wire across the lateral side. After the wire was successfully passaged, the sprinter balloon was passed through the crushed stent to expand it. After 4 days later, the patient was discharged with no symptoms or electrocardiographic change.

The effects of pioglitazone in reducing atherosclerosis progression and neointima volume in type 2 diabetic patients: prospective randomized study with volumetric intravascular ultrasonography analysis

BACKGROUND AND OBJECTIVES

Pioglitazone has been known for its anti-atherogenic effects. We compared the effects of pioglitazone in reducing atherosclerosis progression and neointima volume in type 2 diabetic patients.

SUBJECTS AND METHODS

This was a prospective, randomized single-blinded, 8-month follow-up study. Patients with significant coronary artery stenosis were randomly assigned to either pioglitazone (n=19) or placebo (n=18) following zotarolimus-eluting stent (ZES) implantation. Intravascular ultrasonography of the culprit vessel was performed from 20 mm distal and proximal to the stent at baseline. and at 8-month, and volumetric analysis was performed. Changes in inflammation markers, insulin resistance and lipid profile were compared.

RESULTS

Changes in atherosclerosis progression from baseline in the pioglitazone group was significantly lower than that of the placebo group (0.06±0.73 vs. 1.16±1.41 mm(3)/mm, p=0.024, respectively), and neointima volume was significantly lower in the pioglitazone group compared to the placebo group (1.74±0.93 vs. 2.42±1.98 mm(3)/mm, p=0.007, respectively). Homeostatic model assessment-index, interleukin-6, and tumor necrosis factor-α levels were significantly lower in the pioglitazone group at 8 months. Adiponectin levels increased significantly only in the pioglitazone group. No significant differences in retinol binding protein-4 levels between the 2 groups were seen during the 8-month follow-up period.

CONCLUSION

Compared to placebo, pioglitazone was associated with significant reduction in atherosclerosis progression and neointima formation in type 2 diabetic patients with ZES implantation.

Intravascular ultrasound-guided troubleshooting in a large hematoma treated with fenestration using a cutting balloon

Intramural hematoma formation is not a well-studied complication of percutaneous coronary intervention. We describe a patient with stable angina who developed an intramural hematoma during elective percutaneous coronary intervention (PCI) in the right coronary artery (RCA). Total occlusion with dense dye staining developed a long way from the distal RCA, near the posterior descending artery bifurcation site. The true lumen was compressed by the enlarged, tense, false lumen. The patient was successfully treating with intravascular ultrasound-guided fenestration using a cutting balloon, and a stent was implanted in the distal RCA.