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Objectives: Whether the severity of left main coronary artery (LMCA) disease reflects LMCA and overall coronary atherosclerotic burden is not known. We aimed to assess nonculprit LMCA disease characteristics and the relationship with atherosclerosis in the rest of the coronary arteries as well as patient outcomes., Patients and Methods: In the PROSPECT study, 697 patients with acute coronary syndromes underwent three-vessel gray-scale and radiofrequency intravascular ultrasound after percutaneous coronary intervention., Results: Overall, 552 patients with adequate LMCA imaging were compared according to LMCA plaque burden. The tertile with the highest plaque burden in the LMCA had the smallest LMCA minimum lumen area (17.4, 14.2, 10.5, lowest through highest tertiles, respectively, P<0.0001) and the greatest percent necrotic core volume (2.8, 5.6, 9.5%, lowest through highest tertiles, respectively, P<0.0001). Furthermore, the tertile with the highest plaque burden was also significantly associated with the highest overall non-LMCA percent atheroma volume within the major epicardial arteries (48.3, 49.2, 50.8%, lowest through highest tertiles, respectively, P<0.0001). After adjusting for patient background, the LMCA plaque burden was independently associated with non-LMCA percent atheroma volume (P=0.003). Of the three PROSPECT predictors of future nonculprit major adverse cardiac events (MACE) (minimum lumen area≤4 mm, plaque burden≥70%, and virtual histology thin-cap fibroatheroma), the tertile with the highest LMCA plaque burden had the highest number of patients with at least one of three PROSPECT predictors (P=0.03). In multivariable model, though total atheroma volume (per 1%) was an independent predictor of all MACE [hazard ratio (95% confidence interval)=1.06 (1.01-1.11), P=0.02] and strong trend for non-culprit-related MACE [hazard ratio (95% confidence interval)=1.06 (1.00-1.13), P=0.06], plaque burden at LMCA was not (all MACE, P=0.90, non-culprit-related MACE, P=0.85)., Conclusion: The severity of atherosclerosis in LMCA predicted the overall atherosclerotic plaque burden as well as the presence of high-risk plaques in the three major epicardial coronary arteries.

Background: Fractional flow reserve (FFR) is widely used for the assessment of myocardial ischemia. Intravascular ultrasound (IVUS) is an intracoronary imaging method that provides information about lumen and vessel morphology. Previous studies on the expanded use of IVUS to identify functional ischemia have noted an association between anatomy and physiology, but IVUS-derived minimum lumen area (MLA) has a weak-moderate correlation with myocardial ischemia compared with FFR. We developed a method to calculate FFR using IVUS-derived anatomical information for the assessment of myocardial ischemia. The aims of this study were to investigate the relationship between wire-based FFR and IVUS-derived FFR (IVUS-FFR) and to compare the usefulness of IVUS-FFR and IVUS-derived MLA for functional assessment.Methods and Results:We retrospectively analyzed 50 lesions in 48 patients with coronary stenosis who underwent IVUS and FFR simultaneously. IVUS-FFR was calculated using our original algorithm and fluid dynamics. Mean percent diameter stenosis determined on quantitative coronary angiography and on FFR was 56.4±10.7 and 0.69±0.08, respectively. IVUS-FFR had a stronger linear correlation with FFR (R=0.78, P<0.001; root mean square error, 0.057 FFR units) than with IVUS-derived MLA (R=0.43, P=0.002)., Conclusions: IVUS-FFR may be a more valuable method to identify myocardial ischemia, compared with IVUS-derived MLA.

Thin-cap fibroatheromas (TCFAs) are considered precursors for plaque rupture and subsequent acute coronary events. We investigated intravascular ultrasound (IVUS) and near-infrared spectroscopy (NIRS) characteristics of lesions that were histopathologic TCFAs. IVUS, NIRS, and histopathology were performed in 271 atherosclerotic lesions from 107 fresh coronary arteries from 54 patients at necropsy. The plaque burden and remodeling index calculated by IVUS and maximum lipid core burden index within any 4-mm segment (maxLCBI 4mm ) calculated by NIRS were compared among each plaque type based on histopathologic classifications but focusing on TCFA. Lesions classified as TCFAs had the largest plaque burden, the highest remodeling index, and the greatest maxLCBI 4mm . Plaque burden ≥69% (90% sensitivity, 75% specificity, and area under the curve 0.87); remodeling index ≥1.07 (80% sensitivity, 79% specificity, and area under the curve 0.84); and maxLCBI 4mm ≥323 (80% sensitivity, 85% specificity, and area under the curve 0.84) predicted a histopathologic TCFA. In conclusion, a large plaque burden and a high remodeling index assessed by IVUS and lipid-rich plaque determined by the NIRS maxLCBI 4mm are useful predictive markers of TCFA., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objectives: This study evaluated the relationship between platelet reactivity and plaque morphology using grayscale and radiofrequency intravascular ultrasound (IVUS) virtual histology (VH)., Background: Recent studies have reported that high on-treatment platelet reactivity (HPR) is associated with higher plaque volume and the presence of multivessel disease; however, the association between HPR and plaque morphology has not been evaluated., Methods: The ADAPT-DES (Dual AntiPlatelet Therapy With Drug Eluting Stents) intravascular ultrasound substudy was a prospective, multicenter, observational study of 8,582 patients undergoing percutaneous coronary intervention with drug-eluting stents in whom platelet reactivity on clopidogrel was assessed routinely. The current analysis included 909 culprit lesions from 773 patients with pre-intervention grayscale IVUS and IVUS-VH. HPR was defined as platelet reactivity >208 P2Y12 reaction unit in point-of-care P2Y12 testing by the VerifyNow assay, measured during steady-state platelet inhibition in patients receiving an antiplatelet agent., Results: HPR was associated with 3-vessel coronary artery disease (31.0% vs. 24.4%; p = 0.04). The incidence of fibroatheroma was higher in patients with HPR than those without HPR (77.1% vs. 68.9%; p = 0.01). The HPR group had larger percent plaque and media volume (plaque and media/external elastic membrane volume: 58.1% [95% confidence interval (CI): 57.1% to 59.0%] vs. 56.6% [95% CI: 55.8% to 57.5%]; p = 0.03) and plaque burden at the minimum lumen site (76.7% [95% CI: 75.7% to 77.8%] vs. 75.0% [95% CI: 74.0% to 76.0%]; p = 0.02). Despite a similar prevalence of attenuated plaque, patients with HPR had longer culprit lesion attenuated plaque length (8.0 [95% CI: 7.0 to 9.1] mm vs. 6.5 [95% CI: 5.9 to 7.1] mm; p = 0.01). On multivariate analysis, the presence of angiographic calcium (odds ratio [OR]: 1.85: 95% CI: 1.33 to 2.56; p = 0.0002) and HPR (OR: 1.45; 95% CI: 1.05 to 2.01; p = 0.02) were independent predictors for a culprit lesion fibroatheroma., Conclusions: HPR was associated with increased culprit lesion atherosclerotic burden and adverse plaque morphology among patients undergoing percutaneous coronary intervention. Platelet reactivity might be associated with not only blood clot formation, but also severity of atherosclerosis. (Assessment of Dual AntiPlatelet Therapy With Drug Eluting Stents [ADAPT-DES]; NCT00638794)., (Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Intraprocedural stent thrombosis (IPST) is a rare complication of percutaneous coronary intervention that leads to poor outcomes; however, the factors contributing to IPST remain largely unknown. Accordingly, we used intravascular ultrasound (IVUS) to examine the lesion characteristics in patients with IPST. We retrospectively analyzed 1,504 consecutive stent-implanted lesions in 1,324 patients (326 with ST-segment elevation myocardial infarction [STEMI], 403 patients with non-ST-segment elevation acute coronary syndrome [NSTE-ACS], and 595 patients with stable angina). Of these, IPST occurred in 5 patients during percutaneous coronary intervention (0.4% per patient; 3 with STEMI, 2 with NSTE-ACS). The IVUS characteristics of plaques that developed IPST were compared with those of controls without the evidence of IPST (non-IPST; n = 15) who were matched by age, gender, lesion location, and clinical presentation (STEMI, NSTE-ACS, or stable angina). All 5 lesions that led to IPST had ruptured plaques with positive remodeling and attenuation. Plaque rupture was also observed in 40% of the non-IPST group. Multiple plaque ruptures in the culprit lesion were more common in the IPST group (80% vs 7%; p <0.01). The maximum cavity area was larger in the IPST group than in the non-IPST group having plaque rupture (4.6 mm(2) [interquartile range, 4.3 to 6.5] vs 2.4 mm(2) [1.8 to 2.9]; p <0.01). In conclusion, we found using IVUS that multiple plaque ruptures with larger cavities more often evolved into IPST., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objectives: We report the prevalence and anatomical features of longitudinal stent deformation as detected by intravascular ultrasound (IVUS) BACKGROUND: Angiographic studies have recently reported longitudinal stent deformation as a mechanical complication occurring during percutaneous coronary intervention; however, there are no IVUS studies on this phenomenon, Methods: We retrospectively analyzed 1,489 consecutive stent-treated lesions in 1,057 patients who underwent IVUS post-stent implantation, Results: Seventeen longitudinal stent deformations in 17 lesions (1.1% per lesion) in 17 patients (1.6% per patient) were identified by IVUS. Of the 17 IVUS-detected deformations, only three deformations (17.6%) were detectable by angiography. By IVUS, there were three patterns of longitudinal stent deformation: (1) Deformation with intra-stent wrinkling and overlapping of the proximal and distal stent fragments within a single stent (n = 14), (2) deformation with elongation (n = 2), and (3) deformation with shortening (n = 1). Most of the deformations were located near to the proximal stent edge (88%), consistent with the finding that they were observed in 11 ostial (65%) and eight left main lesions (47%), and 8.3% of 96 left main stented lesions had evidence of deformation, Conclusions: By IVUS, longitudinal stent deformation during percutaneous coronary intervention was seen more frequently than in previous studies; however, it is still uncommon (1.1%) except in the left main location. The most frequent pattern was intrastent wrinkling and overlapping of the proximal and distal stent fragments., (© 2014 Wiley Periodicals, Inc.)

Aims: Mechanical complications contribute to bare metal and first-generation drug-eluting stent (DES) failure. However, the importance of the mechanical complications of second-generation DES remains unclear. We report mechanical complications associated with everolimus-eluting stent (EES) failures., Methods and Results: We retrospectively analysed 177 consecutive EES-treated lesions in 136 patients who underwent intravascular ultrasound (IVUS) at follow-up. Mechanical complications were identified in 17 patients (five stable angina, 10 unstable angina, two non-ST-elevation myocardial infarction [NSTEMI] without angiographic thrombus). Fifteen (88.2%) were treated with repeat revascularisation. By IVUS, there were 16 focal (94.1%) and one diffuse (5.9%) in-stent restenoses. Complete stent fracture with separation was seen in only one, partial stent fracture with separation was seen in three, and in 13 there was longitudinal deformation (n=2) or stent strut fracture (n=11) with overlapping of the proximal and distal stent fragments. In 13 EES with evidence of overlapping in the setting of either fracture or deformation, there was a 35.5±12.2% smaller stent area compared to the adjacent proximal and distal stent fragments, and >50% neointimal hyperplasia in 12 (92.3%)., Conclusions: We found EES mechanical complications, often followed by longitudinal deformation or fracture leading to excessive neointimal hyperplasia, in-stent restenosis, and repeat revascularisation.

Aims: Several studies have demonstrated that type 2 diabetes mellitus (T2DM) is associated with accelerated atherosclerosis, which results in an increased risk of coronary vascular events. However, serial changes in plaque characteristics have not been reported in vivo. We evaluated the progression of coronary atherosclerosis in patients with T2DM using an integrated backscatter intravascular ultrasound (IB-IVUS) examination., Methods and Results: Forty-two T2DM and 48 non-diabetic patients who underwent percutaneous coronary intervention were enrolled in the study. Non-culprit 20-mm length coronary lesions with mild-to-moderate stenosis were measured using a 40-MHz (motorized pullback of 0.5 mm/s) IVUS catheter. IVUS examinations were performed on one target lesion in each patient. Six months later, a follow-up IVUS examination was repeated in the same coronary segment imaged at the baseline examination. T2DM patients demonstrated a greater total plaque volume (TPV; 139 ± 53 vs. 114 ± 45 mm(3), P = 0.02) and total lipid volume (TLV; 67 ± 26 vs. 55 ± 30 mm(3), P = 0.039) at the baseline examination. The progression of TPV (8.6 ± 15.4 vs. -2.2 ± 16.0%, P < 0.01) and TLV (10.8 ± 28.8 vs. -2.5 ± 20.0%, P < 0.05) from the baseline was observed in T2DM patients, but not in non-diabetic patients. The increase in TLV was blunted in T2DM patients who achieved HbA1c levels of <6.5%., Conclusion: Accelerated plaque progression with an increase in the lipid-rich component of non-culprit plaques was observed in T2DM, despite the use of standard medical treatment. Better glycaemic control ameliorated the worsening of plaque characteristics in T2DM.