Distal Reference Segments Research Articles

Optical Coherence Tomography- Versus Angiography-Guided Magnesium Bioresorbable Scaffold Implantation in NSTEMI Patients

BackgroundThe purpose of a bioresorbable scaffold (BRS) is to provide radial support during coronary healing. In this study, coronary artery healing after optical coherence tomography (OCT)- versus angiography-guided magnesium BRS (MBRS) implantation in patients with non-ST-segment-elevation myocardial infarction (NSTEMI) is compared. Methods75 patients were randomized 1:1 to OCT- or angiography-guided implantation of a MBRS with protocolled pre- and post-dilation. In the OCT-guided group, prespecified criteria indicating additional intervention were (1) scaffold under-expansion, (2) strut malapposition, (3) edge dissection, and (4) residual stenosis at distal or proximal reference segments. The primary endpoint was OCT-derived healing stage at 6 months. ResultsAt 6 months, there was no difference in average healing stage between OCT- and angiography-guided intervention (4.6 [interquartile range (IQR): 4.5–4.7] versus 4.5 [IQR: 4.3–4.7]; p = 0.54). The MBRSs were completely resolved in 77.0% [IQR: 68.5–85.5] versus 76.5% [IQR: 67.9–85.5]; (p = 0.97). Minimal lumen area (MLA) was reduced at 6 months in both the OCT- (32.3%; p < 0.01) and the angiography-guided group (21.3%; p < 0.01), however OCT-guided implantation was associated with a greater reduction of total lumen volume (−27.1 ± 32.5 mm3 versus −5.0 ± 32.9 mm3; p < 0.01) and MLA (−2.3 ± 1.6 mm2 vs. −1.4 ± 1.4 mm2; p = 0.02). ConclusionsIn NSTEMI patients, OCT-guidance with protocolled pre- and post-dilation of MBRS implantation showed similar healing pattern at 6 months compared to angiography-guidance alone. Clinical trial registrationThe Coronary Artery Healing Process after Optical Coherence Tomography Guided Percutaneous Coronary Intervention with Magmaris Bioresorbable Scaffold in Patients with Non-ST-Segment-Elevation Myocardial Infarction: (HONEST) trial is registered with ClinicalTrials.gov, NCT03016624.

Follow up coronary vessel evaluation of magnesium bioresorbable stents with coronary computed tomography angiography

Abstract Background Cardiac computed tomography angiography (CCTA) has already shown its ability to evaluate late results of polymer-based bioresorbable scaffolds (BVS) in different clinical scenarios. Recently, magnesium-based BVS (Mg-BVS) has emerged as an interesting alternative to these previous platforms due to its lower risk of thrombosis. Nonetheless, there is no systematic data about characterization of magnesium BVS with CCTA. Purpose To study the feasibility of Mg-BVS assessment with CCTA and to evaluate in-scaffold wall tissue characterization during the follow-up. Methods In this multicentre work, CCTA was performed in patients with a previously implanted Mg-BVS as a supplementary follow-up assessment. All studies were done after the theoretical resorption time of the scaffolds. A central core laboratory with an independent level 3 expert in CCTA blinded to the clinical and angiographic results analysed the studies. For this purpose, a dedicated software for coronary analysis was used to quantify coronary stenosis and evaluate coronary wall (Figure). Results Eight patients (55±6 years-old; 87.5% male) with a previously implanted Mg-BVS from 3 different centres in Spain and Italy were included. The presentation was equally distributed (2, 25%) among stable and unstable angina, NSTEMI and STEMI. Target vessels included 5 left anterior descending (62.5%), 2 left circumflex (25%) and 1 right coronary arteries (12.5%). CTCA was performed 13 [11.3–20] months after BVS implantation. In spite of the blinding, all scaffolds were accurately located through identification of proximal and distal radiopaque markers. Concordance of CCTA Mg-BVS sizing was good for diameter (ICC 0.66; p=0.09) and excellent for length (ICC 0.98; p&amp;lt;0,001) of the stents. Patency of all scaffolds was confirmed without significant diameter (0.14 [0–0.27]%) or area (0.39 [0.19–0.57]%) stenoses compared with proximal reference segments. Moreover, within the stent boundaries the maximum luminal diameter and area narrowing were 0.22 [0,12–0.3]% and 0.39 [0.23–0.5]% respectively, in keeping with mild in-scaffold late loss and/or underlying plaque growth. Regarding coronary wall tissue characterization of segments with BVS, there was a plaque burden of 0.37 [0.31–0.48]% and plaque volume of 87.6 [50.2–189.3] mm3. The most common component of the plaque was fibrous (69.5 [33.9–133.7]%), suggesting that Mg-BVS allows for stabilization of unstable culprit lesions (6/8 cases). Compared to the proximal and distal reference segments, there was no differences in plaque volume or composition, suggesting a good coronary vessel healing. Conclusions This short series shows for the first time the ability of CCTA to correctly locate and evaluate patency of Mg-BVS. Moreover, the lack of metal struts allows a detailed coronary plaque evaluation at treated segments. These preliminary results suggest plaque stabilization and a good coronary vessel healing with this novel scaffold. Funding Acknowledgement Type of funding sources: None. Mg-BVS in LCx with mixed plaque

External elastic lamina vs. luminal diameter measurement for determining stent diameter by optical coherence tomography: an ILUMIEN III substudy.

Optical coherence tomography (OCT)-guided external elastic lamina (EEL)-based stent sizing is safe and as effective as intravascular ultrasound in achieving post-procedural lumen dimensions. However, when compared with automated lumen diameter (LD) measurements, this approach is time-consuming. We aimed to compare vessel diameter measurements and stent diameter selection using either of these approaches and examined whether applying a correction factor to automated LD measurements could result in selecting similar stent diameters to the EEL-based approach. We retrospectively compared EEL-based measurements vs. automated LD in reference segments in 154 OCT acquisitions and derived a correction factor for stent sizing using the ratio of EEL to LD measurements. We then prospectively applied the correction factor in 119 OCT acquisitions. EEL could be adequately identified in 100 acquisitions (84%) at the distal reference to allow vessel diameter measurement. Vessel diameters were larger with EEL-based vs. LD measurements at both proximal (4.12 ± 0.74 vs. 3.14 ± 0.67 mm, P < 0.0001) and distal reference segments (3.34 ± 0.75 vs. 2.64 ± 0.65 mm, P < 0.0001). EEL-based downsizing led to selection of larger stents vs. an LD-based upsizing approach (3.33 ± 0.47 vs. 2.70 ± 0.44, P < 0.0001). Application of correction factors to LD [proximal 1.32 (IQR 1.23-1.37) and distal 1.25 (IQR 1.19-1.36)] resulted in discordance in stent sizing by >0.25 mm in 63% and potentially hazardous stent oversizing in 41% of cases. EEL-based stent downsizing led to selection of larger stent diameters vs. LD upsizing. While applying a correction factor to automated LD measurements resulted in similar mean diameters to EEL-based measurements, this approach cannot be used clinically due to frequent and potentially hazardous stent over-sizing.

Impact of myocardial bridge on late lumen enlargement in distal reference segments after recanalization of coronary chronic total occlusion.

Successful recanalization of coronary chronic total occlusion (CTO) can induce subsequent positive vascular remodeling. Although myocardial bridge (MB) is known to alter endothelial function and wall shear stress, the impact of MB on late lumen enlargement in the distal segment is unclear. A total of 59 patients who underwent successful percutaneous coronary intervention (PCI) for CTO in the left anterior descending artery (LAD) under intravascular ultrasound (IVUS) guidance and follow-up angiography at 8-12months were included. Gray-scale IVUS images were analyzed and MB was detected. Lumen diameter (LD) at distal reference at post-PCI was quantitatively compared with corresponding LD at follow-up coronary angiography to assess late lumen enlargement. MB on IVUS was detected in 17 patients (29%). The length from LAD ostium to the entry of CTO was shorter (11.7 ± 13.9 vs. 22.8 ± 13.4mm, p = 0.006) and LD at distal reference at post-PCI was smaller (1.65 ± 0.54 vs. 1.97 ± 0.56mm, p = 0.049) in patients with MB than those without. At the mean follow-up of 10.4 ± 2.4months, LD at distal reference was significantly increased by 25% from baseline to follow-up in the overall population (1.88 ± 0.57 vs. 2.21 ± 0.41mm, p < 0.001), with a greater increase in patients with MB compared to those without (46 ± 31% vs. 17 ± 29%, p < 0.001). Multivariable analysis indicated MB as an independent predictor of late lumen enlargement. In patients with MB on IVUS, CTO was located in more proximal segment of LAD than those without. Late lumen enlargement at follow-up was greater in patients with MB compared to the counterpart.

Optical coherence tomography versus intravascular ultrasound for culprit lesion assessment in patients with acute myocardial infarction.

IntroductionIn patients with acute myocardial infarction (AMI) undergoing primary percutaneous coronary intervention (PCI) the implanted stent may not fully cover the whole intravascular ultrasound (IVUS)-derived thin-cap fibroatheroma (TCFA) related to the culprit lesion (CL).AimWhether this phenomenon is more pronounced when optical coherence tomography (OCT) assessment of the CL is performed is not known.Material and methodsThus, we aimed to assess CLs in 40 patients with AMI treated with PCI, using VH (virtual histology)-IVUS and OCT before and after intervention. The results were blinded to the operator and PCI was done under angiography guidance.ResultsUncovered lipid-rich plaques were identified in the stent reference segments of 23 (57.5%) patients: in 13 (32.5%) of them in the distal reference segment and in 19 (47.5%) of them in the proximal reference segment. In 9 of them (22.5%) lipid plaques were found in both reference segments. In 36 (90%) patients OCT confirmed lipid plaques identified as VH-derived TCFA by VH-IVUS in the reference segments of the stented segment. However, OCT confirmed that only in 2 (5%) patients were uncovered lipid plaques true TCFA as defined by histology. Comparing IVUS and OCT qualitative characteristics of the stented segments OCT detected more thrombus protrusions and proximal and distal stent edge dissections compared to IVUS (92.5 vs. 55%, p = 0.001; 20% vs. 7.5%, p = 0.03 and 25% vs. 5%, p < 0.001, respectively).ConclusionsDue to its superior resolution, OCT identifies TCFA more precisely. OCT more often shows remaining problems related to stent implantation than IVUS after angiographically guided PCI.

Novel predictors of late lumen enlargement in distal reference segments after successful recanalization of coronary chronic total occlusion.

Although successful recanalization of coronary chronic total occlusion (CTO) can induce subsequent positive vascular remodeling in the distal segment, the predictors are not fully understood. The aim of this study was to investigate the extent and predictors related to luminal gain after successful CTO recanalization. A total of 134 patients who underwent intravascular ultrasound (IVUS)-guided percutaneous coronary intervention (PCI) for CTO and follow-up angiography were included. Angiographic parameters were assessed qualitatively and quantitatively at baseline and follow-up. Gray-scale IVUS images during the PCI procedure were also analyzed. Lumen diameter (LD) at distal reference on the post-PCI angiogram was compared with corresponding LD at follow-up coronary angiography. At the mean follow-up of 10.0 ± 2.7 months, LD at distal reference was significantly increased by 15.9% from baseline to follow-up (2.06 ± 0.62 vs. 2.30 ± 0.55 mm, p < 0.001). Univariable analysis indicated that the left anterior descending artery (LAD), no moderate or severe calcification, presence of peri-medial high-echoic band on IVUS, and impairment of final coronary flow and small distal reference diameter at baseline were associated with greater late lumen enlargement. Multivariable analysis showed the LAD, no moderate or severe calcification, and small LD at distal reference as independent predictors of greater late lumen enlargement. The segment distal to recanalized CTO showed significant late lumen enlargement, especially in the cases with small distal reference, in the LAD, and without moderate or severe calcification.

Optical coherence tomography and intravascular ultrasound assessment of the anatomic size and wall thickness of a muscle bridge segment.

To use optical coherence tomography (OCT) and intravascular ultrasound (IVUS) in assessing myocardial bridging (MB) vessel size and wall thickness. During stent implantation, MB is associated with complications, especially perforation. OCT and IVUS were performed in 56 patients with typical angiographic "milking" from November 2016 to May 2017. The vessel area and thickness in the MB segments and adjacent proximal and distal reference segments were measured and compared with eight normal left anterior descending (LAD) segment (no atherosclerosis in a segment that was at least 20 mm long and that began ~40 mm distal to the LAD ostium). Compared with the reference vessel size distal to the MB segment (6.3 ± 1.8 mm2 ), the IVUS-measured size of the tunneled vessel during diastole was significantly smaller (6.0 ± 1.9 mm2 , p < 0.05) (remodeling index = 0.79 ± 0.18). The minimum intramyocardial arterial wall thickness was 0.16 ± 0.02 mm, significantly thinner than that of the mean reference (0.22 ± 0.03 mm, p < 0.001). The location of the thinnest arterial wall was in the distal and middle MB segments in 45 (80.4%) and 11 (19.6%) patients, respectively, and was not related to the degree of systolic compression or remodeling index. The walls of the middle and distal MB subsegments, but not of the proximal MB subsegment, were thinner than that of the comparison group of normal LADs. The coronary vessel involved in an MB is both smaller and thinner than that of the adjacent non-MB segment. This may explain the increased frequency and severity of coronary perforation during stent implantation.

Imaging Characteristics of Mismatch Lesions: An Angiographic and Intravascular Ultrasound Analysis of 1369 Coronary Lesions.

To evaluate the angiographic and intravascular ultrasound (IVUS) characteristics of coronary mismatch lesions. Better understanding about the characteristics of mismatch lesions may help to achieve more accurate lesion assessment and, thereby, to improve the outcomes of percutaneous coronary intervention (PCI). Angiographic and IVUS data from 1369 lesions were analyzed. Mismatch lesion was defined as the difference between proximal and distal reference lumen diameters of ≥1.0 mm or ≥30% of the distal reference lumen diameter. The incidence of mismatch lesions was 20.1% (275/1369). Compared to nonmismatch group, mismatch group had longer lesions (21.3 [6.4] mm vs 18.4 [6.4] mm, P < .001) with smaller minimum lumen diameter (0.87 [0.29] mm vs 1.10 [0.31] mm, P < .001) and more severe diameter stenosis (78.8% [9.2%] vs 66.3% [10.3%], P < .001). On IVUS, mismatch group had larger lumen area (18.7 [5.0] vs 15.8 [5.1] mm2, P < .001) but lower plaque burden at the proximal reference segment (41.0% [9.2%] vs 45.7% [9.9%], P < .001) and smaller lumen area (4.83 [1.89] vs 7.36 [2.89] mm, P < .001) but higher plaque burden at the distal reference segment (42.9% [10.4%] vs 41.4% [10.1%], P = .023). Multivariable logistic regression analysis showed that mismatch lesions were frequently accompanied by diffuse lesions (odds ratio [OR] = 2.50; 95% confidence interval [CI]: 1.83-3.40; P < .001), bifurcation lesions (OR = 5.83; 95% CI: 4.40-7.74; P < .001), and lesions with a low TIMI flow grade (OR = 1.70; 95% CI: 1.08-2.67; P = .022) or severe diameter stenosis (OR = 3.05; 95% CI: 2.10-4.43; P < .001). Mismatch lesions are quite common and characterized by greater lesion complexity compared with nonmismatch lesions. Further studies may be necessary to address the impact of this lesion type on the outcome of PCI.

Absence of adventitial vasa vasorum formation at the coronary segment with myocardial bridge - An optical coherence tomography study.

Myocardial bridge (MB) is a myocardial bundle through which coronary segment tunnels and could compress coronary arteries causing myocardial ischemia. However, the characteristic structural findings of MB remain to be fully elucidated. Recently, we demonstrated that optical coherence tomography (OCT) enables us to visualize adventitial vasa vasorum (VV) formation in humans. In this study, we examined adventitial VV formation at the coronary segment with MB in humans using OCT. We examined 15 consecutive patients with suspected angina pectoris and MB in the left anterior descending (LAD) coronary arteries but no angiographic coronary stenosis. MB was detected on coronary angiography as a segment with milking effect. We performed intracoronary OCT imaging along the entire LAD. Morphometric analysis was performed at MB and proximal/distal segments at every 1mm. OCT examination showed the absence of adventitial VV formation at MB in the LAD, while VV was clearly noted at both the proximal and distal reference segments. Adventitial VV area was significantly less at MB compared with the proximal or distal references. These results with OCT imaging indicate that coronary segments with MB lack adventitial VV formation in humans, suggesting that MB could influence morphological and functional changes of the coronary artery.

Full Metal Jacket With Drug-Eluting Stents for Coronary Chronic Total Occlusion

ObjectivesThe aim of this study was to evaluate the long-term outcomes and predictors of adverse events following successful “full metal jacket” (FMJ) (stent length ≥60 mm without gap) procedures using drug-eluting stents to treat coronary chronic total occlusions (CTOs). BackgroundThe FMJ stenting procedure is often required to treat CTOs, but its clinical efficacy and safety remain unknown. MethodsIn total, 1,126 successful CTO procedures (1,107 consecutive patients) performed between May 2003 and March 2015 were studied. The primary endpoint was target lesion failure, a composite of cardiac death, target vessel–related myocardial infarction, or target lesion revascularization or reocclusion. ResultsOverall, 406 patients (36.7%) underwent the FMJ procedure, increasing in frequency over time (28.5% from 2003 to 2006 and 41.7% after 2011). The mean stent length was 76.8 ± 14.6 mm (range 60 to 122 mm), and the average number of stent overlaps was 2.5 ± 0.6 (range 2 to 4). A total of 127 patients (31.3%) had persistent luminal narrowing at the distal reference segment after stenting. During the median follow-up period of 5.1 years, target lesion failure occurred in 16.0% of patients. There were 17 cases of total reocclusion and 5 cases of stent thrombosis. Multivariate analysis confirmed that the number of implanted stents (hazard ratio: 1.72; 95% confidence interval: 1.16 to 2.54; p = 0.006) and persistent distal luminal narrowing (hazard ratio: 2.73; 95% confidence interval: 1.66 to 4.47; p < 0.001) were predictors of increased risk for target lesion failure. ConclusionsThe FMJ procedure using drug-eluting stents for CTOs provides acceptable long-term clinical results. Persistent distal luminal narrowing increases the future likelihood of adverse events despite procedural success.

Lipid-core burden response to stent implantation assessed with near-infrared spectroscopy and intravascular ultrasound evaluation in patients with myocardial infarction.

Near-infrared spectroscopy (NIRS) is a new method to identify lipid core plaque (LCP). The LCP and vascular response were assessed with NIRS to examine whether LCP was compressed or redistributed during percutaneous coronary intervention with stent implantation. In 25 patients with non-ST segment elevation myocardial infarction (NSTEMI) NIRS acquisition was performed after predilation, stent implantation with nominal pressure and high-pressure post-dilation with a non-compliant balloon. The intravascular ultrasound (IVUS) measures included volumes of external elastic membrane (EEM), lumen and plaque+media. The NIRS measures included lipid core burden index (LCBI) and maximum value of LCBI for any of the 4-mm segment (maxLCBI4mm). From predilation to stent implantation and post-dilation EEM volume increased from 337±124mm3 to 369±136mm3 and to 397±144mm3 (p<0.001), while plaque volume decreased from 225±84mm3 to 202±85mm3 and to 192±81mm3 (p<0.001). Plaque shift to the proximal reference segment was found in 40% of the lesions. The maxLCBI4mm decreased significantly from predilation to stent implantation (492±235 to 208±193 (p<0.001), whereas post dilation did not cause any further significant reduction. Also LCBI decreased significantly from predilation to stent implantation (173±103 to 68±67, p<0.001), without any further significant reduction during post-dilation. The LCBI did neither in the proximal nor in the distal reference segments change significantly during stent implantation or post-dilation. Lumen enlargement was caused by vessel expansion, plaque compression and longitudinally plaque redistribution. Lipid-core burden at the stented segment was decreased.

Pattern of vascular remodeling of distal reference segment after recanalization of chronic total occlusion, long-term angiographic follow-up

Chronic total occlusion (CTO) is probably caused by thrombus and lipid-rich cholesterol esters that are replaced over time by collagen and calcium deposition. Experimental models showed endothelial cell necrosis in response to vessel ligation, whereas more recent models suggest that the endothelium might retain viability guiding the subsequent development of CTO, including CTO neo-revascularization, which occurs within the lumen and in various layers of the vessel wall, by the release of paracrine substances. It is uncertain whether after CTO recanalization the recovery of anterograde reverses endothelial dysfunction, thus promoting vasodilation and positive remodeling.

Predictores de eventos cardiovasculares adversos mayores en la ecocardiografía intravascular tras el implante de stents liberadores de everolimus en lesiones coronarias largas

Introduction and objectivesThere are limited data on the usefulness of intravascular ultrasound (IVUS) for long coronary lesions treated with second-generation drug-eluting stents. We evaluated IVUS predictors of major adverse cardiovascular events (MACE) 12 months after implantation of everolimus-eluting stents for long coronary lesions. MethodsA total of 804 patients who underwent both postintervention IVUS examination and long everolimus-eluting stent (≥ 28 mm in length) implantation were included from 2 randomized trials. MACE was defined as a composite of cardiac death, myocardial infarction, and target-lesion revascularization. ResultsMACE occurred in 24 patients (3.0%) over 12 months. On multivariable Cox regression analysis, independent IVUS predictors of MACE included the postintervention minimum lumen area (MLA) at the target lesion (HR = 0.623; 95%CI, 0.433-0.895; P = .010) and the ratio of MLA/distal reference segment lumen area (HR = 0.744; 95%CI, 0.572-0.969; P = .028). The MLA and MLA-to-distal reference segment lumen area ratio that best predicted patients with MACE from those without these events were 5.0 mm2 and 1.0, respectively. Patients with MLA < 5.0 mm2 or a distal reference segment lumen area had a higher risk of MACE (HR = 6.231; 95%CI, 1.859-20.891; P = .003) than those without MACE. ConclusionsPatients with a postintervention IVUS-measured MLA of < 5.0 mm2 or a distal reference segment lumen area were at risk for MACE after long everolimus-eluting stent implantation.Full English text available from: www.revespcardiol.org/en

Intravascular Ultrasound Predictors of Major Adverse Cardiovascular Events After Implantation of Everolimus-eluting Stents for Long Coronary Lesions

Introduction and objectivesThere are limited data on the usefulness of intravascular ultrasound (IVUS) for long coronary lesions treated with second-generation drug-eluting stents. We evaluated IVUS predictors of major adverse cardiovascular events (MACE) 12 months after implantation of everolimus-eluting stents for long coronary lesions. MethodsA total of 804 patients who underwent both postintervention IVUS examination and long everolimus-eluting stent (≥ 28mm in length) implantation were included from 2 randomized trials. MACE was defined as a composite of cardiac death, myocardial infarction, and target-lesion revascularization. ResultsMACE occurred in 24 patients (3.0%) over 12 months. On multivariable Cox regression analysis, independent IVUS predictors of MACE included the postintervention minimum lumen area (MLA) at the target lesion (HR = 0.623; 95%CI, 0.433-0.895; P=.010) and the ratio of MLA/distal reference segment lumen area (HR = 0.744; 95%CI, 0.572-0.969; P=.028). The MLA and MLA-to-distal reference segment lumen area ratio that best predicted patients with MACE from those without these events were 5.0 mm2 and 1.0, respectively. Patients with MLA<5.0 mm2 or a distal reference segment lumen area had a higher risk of MACE (HR = 6.231; 95%CI, 1.859-20.891; P=.003) than those without MACE. ConclusionsPatients with a postintervention IVUS-measured MLA of<5.0 mm2 or a distal reference segment lumen area were at risk for MACE after long everolimus-eluting stent implantation.

Pattern of vascular remodeling of distal reference segment after recanalization of chronic total occlusion: Long term angiographic follow up

Chronic total occlusion (CTO) is probably caused by thrombus and lipid-rich cholesterol esters that are replaced over time by collagen and calcium deposition. Experimental models showed endothelial cell necrosis in response to vessel ligation, whereas more recent models suggest that the endothelium might retain viability guiding the subsequent development of CTO, including CTO neo-revascularization, which occurs within the lumen and in various layers of the vessel wall, by the release of paracrine substances. It is uncertain whether after CTO recanalization the recovery of anterograde reverses endothelial dysfunction, thus promoting vasodilation and positive remodeling.

Optical coherence tomography assessment of incidence, morphological characteristics, and spontaneous healing course of edge dissections following percutaneous coronary intervention with stent implantation in patients with non-ST segment elevation myocardial infarction

BackgroundStenting-induced edge dissections (ED) can be assessed in detail by optical coherence tomography (OCT). This study sought to investigate the incidence, morphological characteristics, and spontaneous healing course of OCT-identified EDs following drug-eluting stent (DES) implantation in a non-ST segment elevation myocardial infarction (NSTEMI) patient-population. MethodsAcute vessel wall injury at the 5-mm stent adjacent distal and proximal reference segments was assessed by post-procedure OCT and intravascular ultrasound (IVUS) in n=97 NSTEMI-patients (n=97 lesions). Six months OCT follow-up was available in 82 patients (including 35 untreated post-procedure EDs). ResultsThe overall incidence of post-procedure OCT-detected ED was 38 per 97 patients (39.2%), and 47 per 182 stent edges (25.8%). None of the EDs were angiographically visualizable, while 10 (21.3%) were visible on concomitant IVUS-analysis. Morphologically, there was a significant difference in plaque type present at ED-edges vs. non-ED-edges when assessed with OCT; (1) lipid-rich and calcified plaques: 80.9% vs. 57.0%, (2) fibrous plaques: 17.0% vs. 26.7%, and (3) normal coronary vessels: 2.1% vs. 16.3%, p<0.01. Plaqueburden, assessed by IVUS, was substantially larger at ED-containing borders: 54.5±10.0% vs. 43.7±11.6%, p=0.01. Three dissections (8.6%) were incompletely healed at 6-month OCT follow-up. None of the EDs caused cardiac events during the 6-month follow-up, however, 1 ED-patient had target lesion revascularization with PCI and DES-implantation in extension of the scheduled OCT-control. ConclusionsOCT-detected EDs were frequent after stent implantation due to NSTEMI, and the majority of these EDs healed without leading to an adverse prognosis at 6months.

Impact of intracoronary injection of CD133+ bone marrow stem cells on coronary atherosclerotic progression in patients with STEMI: a COMPARE-AMI IVUS substudy.

Adverse effects of intracoronary injection of stem cells on in-stent restenosis and atherosclerotic progression remain unclear. We sought to evaluate the adverse effects of intracoronary injection of CD133 cells on in-stent restenosis and atherosclerotic progression in the infarct-related and contralateral arteries using serial intravascular ultrasound (IVUS) analysis. Baseline and 4-month follow-up IVUS images were obtained from 17 patients treated with intracoronary stem cell injection and 20 placebo patients after primary percutaneous coronary intervention in the COMPARE-AMI trial. In the infarct-related artery, the stented segment, 5 mm proximal and distal reference segments, and proximal and distal nonstented segments were analyzed every 1 mm; the entire segment of a contralateral artery was also analyzed every 1 mm. In the infarct-related artery analysis, the median percentage of in-stent neointimal hyperplasia (12.1 vs. 7.6%, P=0.95), the reduction in the minimum lumen area (MLA; -1.6 vs. -1.5 mm(2), P=0.97), and the MLA at follow-up (4.3 vs. 5.3 mm(2), P=0.21) were found to be similar between the stem cell and placebo groups. Changes in proximal and distal nonstented segment lumen areas and plaque burden were also similar between the stem cell and placebo groups; however, there was a decrease in the maximum arc of the attenuated plaque behind the stent from baseline to follow-up in the placebo group (P=0.004), but not in the stem cell group. In the contralateral artery, there were no differences in changes in MLA, plaque burden, or attenuated plaque between stem cell and placebo patients. Intracoronary injection of CD133(+) bone marrow stem cells has no IVUS-detectable effect on neointimal hyperplasia or atherosclerosis progression in either infarct-related or contralateral arteries.

Pattern of Vascular Remodeling of Distal Reference Segment after Recanalization of Chronic Total Occlusion, Long Term Angiographic Follow Up

Stress echocardiography is a sensitive and specific noninvasive technique for evaluation of my-ocardial ischemia. Stress echocardiography is portable and does not involve ionizing radiation. A known limitation of stress echocardiography is inadequate definition of the endocardial border, especially in patients with suboptimal imaging windows. Contrast echocardiography is indicated for detection or definition in these patients or in cases where more than two cardiac segments are not adequately visualized. To date, few studies have evaluated the long-term prognostic value of contrast stress echocardiography. This study sought to determine the prognostic value of contrast stress echocardiography in patients at low to intermediate risk of coronary atherosclerotic disease. Methods: Patients referred to the Emory University Hospital echocardiography lab for stress echocardiography and received Optison (R) contrast for left ventricular (LV) endocardial enhancement were included in this study. Patients received contrast when two or more cardiac segments were not adequately visualized. Demographic data and indication for examination was collected for each patient. Each study was classified as either negative for ischemia or positive if there was a new wall motion abnormality or worsening of a baseline abnormality. The comprehensive electronic medical record was subsequently reviewed for major adverse cardiovascular events including death from any cause, death from a cardiovascular cause, myocardial infarction, congestive heart failure exacerbation, need for hospitalization for anginal chest pain, need for revascularization. This study was approved by the Emory University Hospital institutional review board. Results: Fifty-one patients met the inclusion criteria for this study. Three patients had a positive stress echocardiogram. Of these three patients, one was treated with optimal medical therapy and the other two underwent angiography with percutaneous coronary intervention. During the mean follow-up period of 2.2 +/- 1.02 years (median 1.95 years) there was one death attributed to a patient discharge to Hospice, and there were no deaths attributable to a cardiac etiology. There was one hospitalization for unstable angina and one hospitalization for a congestive heart failure exacerbation in the same patient. No patients underwent revascularization or had a myocardial infarction. Three cardiac catheterizations were performed during the follow-up period with no significant coronary artery disease. Conclusions: Contrast stress echocardiography is useful for the noninvasive assessment of myocardial is-chemia. A negative contrast stress echocardiogram conveys a favorable prognosis over a two year period with a 98.0% negative predictive value.

Avoid overtreatment in the setting of chronic total occlusions: The role of blood flow restoration in positive vascular remodeling

A coronary chronic total occlusion (CTO) promotes negative remodeling in distal segments by negative vascular wall remodeling and plaque growth [ [1] Park J.J. Chae I.H. Cho Y.S. et al. The recanalization of chronic total occlusion leads to lumen area increase in distal reference segments in selected patients: an intravascular ultrasound study. JACC Cardiovasc. Interv. Aug 2012; 5: 827-836 Crossref PubMed Scopus (31) Google Scholar ]. As a result, epicardial coronary segments located distal to a CTO appear often as diffusely diseased arteries [ [2] Werner G.S. Schwarz G. Prochnau D. et al. Paclitaxel-eluting stents for the treatment of chronic total coronary occlusions: a strategy of extensive lesion coverage with drug-eluting stents. Catheter. Cardiovasc. Interv. 2006; 67: 1-9 Crossref PubMed Scopus (46) Google Scholar ]. It is unknown if these lesions are related to clinical events at follow-up and if they require percutaneous coronary intervention (PCI) with stenting, because blood flow restoration by recanalisation potentially leads to positive vascular remodeling in the distal reference segments [ [3] Gasparini G.L. Rossi M.L. Presbitero P. Follow-up improvement of distal vessel diameter after successful chronic total coronary occlusion recanalization. JACC Cardiovasc. Interv. Apr 2014; 7: e31-e33 Crossref PubMed Scopus (4) Google Scholar ]. Few data have been published to investigate the role of blood flow restoration in remodeling process after successful CTO PCI. A study of Park et al. [ [1] Park J.J. Chae I.H. Cho Y.S. et al. The recanalization of chronic total occlusion leads to lumen area increase in distal reference segments in selected patients: an intravascular ultrasound study. JACC Cardiovasc. Interv. Aug 2012; 5: 827-836 Crossref PubMed Scopus (31) Google Scholar ] showed that recanalization of a CTO led to lumen area increase in two-thirds of the patients. Independent predictors of lumen area increase were occlusion duration, a poor collateral flow and statin use. The degree of collateral flow might reflect the magnitude of hemodynamic stimuli deprivation, whereas the CTO duration correlates with the time in which vessels undergo a negative remodeling process. In a study of Galassi et al. [ [4] Galassi A.R. Tomasello S.D. Crea F. et al. Transient impairment of vasomotion function after successful chronic total occlusion recanalization. J. Am. Coll. Cardiol. Feb 21 2012; 59: 711-718 Crossref PubMed Scopus (70) Google Scholar ] authors have suggested that improvement of distal vessel diameter after CTO recanalization can be explained by an impaired endothelium-dependent and/or -independent vasomotion immediately after CTO recanalization, that improves at follow-up, or by a positive remodeling or by a combination of both. Gomez-Lara et al. [ [5] Gomez-Lara J. Teruel L. Homs S. et al. Lumen enlargement of the coronary segments located distal to chronic total occlusions successfully treated with drug-eluting stents at follow-up. EuroIntervention. Feb 2014; 9: 1181-1188 Crossref PubMed Scopus (32) Google Scholar ] have documented a notable late lumen enlargement between baseline and follow-up. These findings can be explained either by the absence of vasomotor response to non-endothelium-mediated stimuli immediately after the procedure and plaque regression. At follow-up, endothelium-independent response was restored in most patients, showing a remarkable luminal gain compared to the index procedure.

Prediction of Chronic Vessel Enlargement by a Novel Intravascular Ultrasound Finding

Coronary arterial segments distal to the severely stenotic lesion sometimes shrink as a result of decreased coronary flow. Pathological studies have shown that vessel shrinkage is accompanied by folding of the internal elastic membrane (IEM). A peri-medial high-echoic band (PHB) by intravascular ultrasound (IVUS) may represent folding of the IEM and therefore detect chronically shrunken coronary segments that have potential to enlarge subsequently. METHODS AND RESULTS: IVUS imaging of the distal reference segments was performed in 27 patients after stenting. PHB was defined as a high-echoic band observed at the luminal side of the media. Serial (baseline and 9 months) changes in minimal lumen diameter (LD) were compared between those with (PHB group) and without PHB (non-PHB group). During follow-up, LD increased significantly in PHB group (1.2±0.3 vs. 1.7±0.5 mm, P=0.001) but not in the non-PHB group (2.0±0.7 vs. 2.1±0.7 mm, P=NS). Late lumen gain (LLG) was observed in 16 of the 27 (59%) lesions. Lesions with LLG showed a trend toward smaller baseline lumen cross-sectional area and significantly higher prevalence of PHB (88% vs. 18%, P=0.007). By multivariable logistic regression analysis, PHB was the only IVUS predictor of LLG. Presence of PHB on IVUS predicts chronic enlargement of the coronary segments distal to the stented lesion.