Three-dimensional Intravascular Ultrasound Analysis Research Articles

Abstract 11675: Influence of Donor-Transmitted Lesions on Vessel Remodeling and Plaque Progression in Coronary Artery After Heart Transplant Recipients: Serial Three-Dimensional Intravascular Ultrasound Analysis

Introduction: The association between the presence of donor-transmitted lesions (DL) and the progression of cardiac allograft vasculopathy (CAV) including coronary vessel remodeling has been still controversial. The purpose of present study was to elucidate the influence of DL on coronary artery morphology after heart transplantation (HTx). Methods: Serial three-dimensional intravascular ultrasounds (3D-IVUS) analyses were performed in 50 HTx recipients at 9.0±3.6 weeks after HTx and annually thereafter for 5 years. Sites at baseline with maximum intimal thickening≧0.5 mm of anterior descending artery (LAD) were defined as DL. Significant functional narrowing by IVUS was defined as %plaque area (plaque area/vessel area) >40%. A mixed-model repeated-measures analysis was used. Results: DL was present in 54.0% in all recipients. In the first year after HTx, plaque volume significantly increased from 2.04±1.22 to 2.59±1.54 mm 3 /mm (p<0.01) in recipients with DL. Furthermore, the increase of plaque volume during 1 year after HTx was significantly higher in recipients with DL (0.62±0.85 vs 0.16±0.50 mm 3 /mm, p=0.048). Vessel volume in recipients with DL were greater than without DL at 1 year after HTx (12.84±3.15 vs 10.84±2.78 mm 3 /mm, p=0.024). Thereafter, the vessel volume decreased in both groups during 5 years. Consequently, the incidence of functional narrowing up to 5 years was higher in recipients with DL than in without DL (66.7% vs 30.4%, p=0.001). Cox proportional hazard model showed that the presence of DL increased the risk of functional narrowing (hazard ratio:HR3.38, 95% confidence interval 1.35-8.45) after adjusting for donor age, donor sex and the level of high density lipoprotein at 1 year. Conclusions: The presence of DL influenced not only the increase of plaque volume during the first year but also the vessel remodeling during 5 years. Recipients with DL have a higher incidence of significant functional narrowing by IVUS.

Impact of Donor-Transmitted Atherosclerosis on Early Cardiac Allograft Vasculopathy: New Findings by Three-Dimensional Intravascular Ultrasound Analysis

The influence of donor-transmitted coronary atherosclerosis (DA) on plaque progression during the first year after cardiac transplantation (Tx) is unknown. Serial 3-dimensional intravascular ultrasound (IVUS) studies were performed within 8 weeks (baseline; BL) and at 1 year after Tx in 38 recipients. On the basis of maximum intimal thickness (MIT) at BL, recipients were divided into DA group (DA+; MIT≥0.5 mm, n=23) or non-DA group (DA-; MIT<0.5 mm, n=15). Plaque, lumen, and vessel volume indexes were calculated by volume/measured length (mm/mm) in the left anterior descending artery. Univariate and multivariate regression analyses were attempted to reveal clinical predictors of change in coronary dimensions. During the first year after Tx, plaque volume index increased significantly in DA+ group, but did not change in DA- Group (DA+, 3.0±1.5 to 4.1±1.5 mm/mm, P<0.0001: DA-, 1.2±0.4 to 1.3±0.5 mm/mm, P=0.53). In both groups vessel volume index decreased significantly (DA+, 16.3±3.6 to 14.6±3.3 mm/mm, P=0.003: DA-, 13.5±4.1 to 12.0±3.3 mm/mm, P=0.01), as did lumen volume index (DA+, 13.2±3.1 to 10.5±2.7 mm/mm, P<0.0001: DA-, 12.2±3.7 to 10.7±3.0 mm/mm, P=0.004). Univariate and multivariate regression analyses revealed that DA was one of the strongest predictors for plaque progression. DA was associated with significant plaque progression during the first year after Tx, and in conjunction with negative remodeling, may be an important determinant of cardiac allograft vasculopathy.

Comparison of Everolimus- Versus Paclitaxel-Eluting Stents Implanted in Patients With Diabetes Mellitus as Evaluated by Three-Dimensional Intravascular Ultrasound Analysis

Previous reports have shown the advantage of paclitaxel compared to limus-derivative drugs for the treatment of diabetics. A total of 109 diabetics (115 lesions) treated with everolimus-eluting stents (EESs, n = 58) or paclitaxel-eluting stents (PESs, n = 55) undergoing 8 to 9 months of follow-up 3-dimensional intravascular ultrasound examinations were enrolled. In addition to the standard intravascular ultrasound parameters, the percentage of neointimal volume (neointimal volume/stent volume) and maximum percentage of cross-sectional narrowing (neointimal area/stent area) was calculated. EESs showed a lower percentage of neointimal volume (7.2 +/- 7.1% vs 11.7 +/- 11.0%; p = 0.01) and maximum percentage of cross-sectional narrowing (22.5 +/- 16.3% vs 29.4 +/- 19.2%; p = 0.04) than PESs. One case of severe narrowing (lesions with maximum percentage of cross-sectional narrowing >60%) in the EES group developed and 6 cases in the PESs group (p = 0.05). The EESs showed no serial changes for vessel or peri-stent plaque during the follow-up period, and PESs showed significant increases in vessel and peri-stent plaque. PESs showed significantly greater peri-stent plaque increase, with a tendency toward greater vessel enlargement than EESs. Late acquired incomplete stent apposition was observed in 2 PES cases. The major adverse cardiac event rate was comparable < or =2 years. In conclusion, EESs showed greater neointimal suppression without significant vessel expansion than PESs in diabetic patients. In this small cohort, no significant differences were observed in the major adverse cardiac event rate < or =2 years.

Stents liberadores de sirolimus com e sem cobertura polimérica: análise seriada com angiografia e ultrassom intracoronariano tridimensional

INTRODUÇÃO: A presença de polímeros sintéticos em contato com a parede vascular tem sido associada a intensa resposta inflamatória local e a eventos adversos tardios. Entretanto, sua ausência pode comprometer a eficácia dos stents farmacológicos em suprimir a hiperplasia intimal. Avaliamos, com angiografia coronariana quantitativa (ACQ) e ultrassom intracoronariano (USIC), a eficácia do stent VestasyncTM (VES), liberador não-polimérico de sirolimus em baixa dose (55 µg), e do stent CypherTM (CYP), liberador de sirolimus polimérico em alta dose (140 µg). MÉTODO: Quinze pacientes com lesões primárias < 14 mm, em artérias coronárias nativas de 2,5 mm a 3,5 mm, foram tratados com VES e comparados a uma coorte histórica de 15 pacientes tratados com CYP. ACQ e USIC foram realizados pós-procedimento, aos 4 e 12 meses. Desfechos primários foram: perda tardia intrastent e porcentual de obstrução volumétrica intrastent. RESULTADOS:As características clínicas eram semelhantes. O grupo VES tinha vasos menores (2,67 ± 0,32 mm vs. 2,98 ± 0,4 mm; P = 0,02). Aos 4 meses, o grupo VES mostrou tendência a maior perda tardia intrastent (0,30 ± 0,25 mm vs. 0,10 ± 0,3 mm; P = 0,06), mas porcentual de obstrução volumétrica intrastent similar ao do grupo CYP (2,8 ± 2,2% vs. 2,2 ± 3,8%; P = 0,60). Aos 12 meses, a perda tardia intrastent foi de 0,37 ± 0,24 mm no grupo submetido a implante de stent VES vs. 0,16 ± 0,36 mm no grupo submetido a implante de stent CYP (P = 0,074), e o porcentual de obstrução volumétrica intrastent foi de 4,0 ± 2,2% no grupo que recebeu stent VES vs. 2,4 ± 3,9% no grupo que recebeu stent CYP (P = 0,17). Não houve casos de reestenose binária. CONCLUSÕES: O stent VES mostrou-se seguro e eficaz em suprimir a hiperplasia intimal até 12 meses. Ausência do polímero e dosagem reduzida da droga não comprometeram sua eficácia. Estudos maiores e com seguimento mais longo são necessários para avaliar se esses achados melhorarão o perfil de segurança dos stents farmacológicos.

Long-Term Histopathologic and IVUS Evaluations of a Novel Coiled Sheet Stent in Porcine Carotid Arteries

Carotid angioplasty with stent placement has been proposed as an alternative method for revascularization of carotid artery stenosis. A novel stent with a laser-cut, rolled sheet of Nitinol (EndoTex Interventional Systems, Inc., Cupertino, CA) has been developed to customize treatment of stenotic lesions in carotid arteries utilizing a single stent, designed to adapt to multiple diameters and to tapered or nontapered configurations. The purpose of this study is to evaluate the conformability and vascular response to a novel stent in a chronic porcine carotid model using serial three-dimensional intravascular ultrasound (IVUS) analysis as well as histological examination. Ten Yucatan pigs underwent stent implantation in both normal carotid arteries with adjunctive balloon angioplasty. Three-dimensional IVUS analysis was performed before stent implantation, after adjunctive balloon angioplasty, and at follow-up [1 month (n = 6), 3 months (n = 6), or 6 months (n = 8)]. Histological examination (injury score, percent plaque obstruction, and qualitative analysis) was also performed. All stents were successfully deployed and well apposed in different sized vessels (lumen area range: 19-30 mm(2)). Volumetric IVUS analysis showed no significant difference between the lumen areas before stent implantation and after adjunctive balloon angioplasty and no stent area change at each follow-up point compared to immediately postprocedure. Histological examination revealed minimal injury and neointimal hyperplasia at each follow-up point. In the chronic porcine carotid model, the novel stent system demonstrated good conformability, resulting in minimal vessel injury and neointimal formation.

Angiographic and three-dimensional intravascular ultrasound analysis of combined intracoronary beta radiation and self-expanding stent implantation in human coronary arteries

This study tested the combination of vascular brachytherapy (VBT) and self-expanding Wallstent implantation in coronary lesions of patients at high risk for restenosis as assessed angiographically by quantitative coronary analysis and by 3-dimensional intravascular ultrasound analysis. Twenty-nine "de novo" lesions were managed with a self-expanding stent alone (n = 19) or with a self-expanding stent after beta-VBT (n = 10) in 27 patients who had been identified by high levels of plasma angiotensin-converting enzyme as being prone to myointimal growth after stent implantation. At 6 months, the increase in stent strut diameter was similar in the 2 groups by quantitative coronary analysis and 3-dimensional intravascular ultrasound (Delta mean stent strut diameter -0.33 +/- 0.3 vs -0.40 +/- 0.3 mm, p = 0.5; Delta stent area -11.8 +/- 6.1 vs -12.0 +/- 6.1 mm(2), p = 0.9; Delta stent volume -96.9 +/- 112 vs -83.5 +/- 73 mm(3), p = 0.7; for groups treated with VBT and self-expanding stents and only self-expanding stents, respectively). In-stent neointimal proliferation was decreased in the group treated with VBT and self-expanding stents (minimal luminal diameter 2.5 +/- 0.8 vs 1.88 +/- 0.8 mm, p = 0.04) by quantitative coronary analysis (minimal luminal area 6.7 +/- 2.5 vs 4.1 +/- 1.9 mm(2), p = 0.01), by intravascular ultrasound, and proliferation volume (84.6 +/- 66.4 vs 159.2 +/- 103.5 mm(3), p = 0.05) by 3-dimensional intravascular ultrasound. Positive vessel and luminal remodelings were observed in 50% of the group treated with VBT and self-expanding stents and in 11% of the group treated only with self-expanding stents (p = 0.02). The combined use of VBT and self-expanding stents is a novel approach that enlarges vascular lumen by preventing vessel constriction and neointimal proliferation. The feasibility and good results of this experimental approach suggest that the simultaneous use of these 2 technologies may be an interesting alternative for difficult vascular districts with high restenosis rates, such as peripheral circulation in the lower limbs.

Edge effect does not occur after implantation of sirolimus-eluting stents: a three-dimensional intravascular ultrasound analysis from the RAVEL trial

Edge effect does not occur after implantation of sirolimus-eluting stents: a three-dimensional intravascular ultrasound analysis from the RAVEL trial

Is there a difference in the mechanisms of lumen enlargement with direct stenting as compared to stenting with predilatation? A three-dimensional intravascular ultrasound analysis Gerard Finet, Neil J. Weissman, Lowell F. Satler, Kenneth M. Kent, Marco T. Castagna, Augusto D. Pichard. Washington Hospital Center, Washington, DC

Is there a difference in the mechanisms of lumen enlargement with direct stenting as compared to stenting with predilatation? A three-dimensional intravascular ultrasound analysis Gerard Finet, Neil J. Weissman, Lowell F. Satler, Kenneth M. Kent, Marco T. Castagna, Augusto D. Pichard. Washington Hospital Center, Washington, DC

Serial automated three-dimensional intravascular ultrasound analysis of the self-expanding radius stent

Automated 3-dimensional intravascular ultrasound (IVUS) analysis was used to assess status of the treated coronary artery immediately and 6 months after placement of a self-expanding Radius stent in 15 patients. Serial 3-dimensional IVUS analysis demonstrated gradual stent expansion that countered neointimal proliferation and preserved the lumen.

Successful Directional Atherectomy of De Novo Coronary Lesions Assessed With Three-Dimensional Intravascular Ultrasound and Angiographic Follow-Up

Recent histopathologic and intravascular ultrasound (IVUS) data indicate that inadequate compensatory enlargement of atherosclerotic lesions contributes to the development of significant arterial stenoses. Such lesions may contain less plaque, which may have implications for atheroablative interventions. In this study, we compared lesions with (group A, n = 16) and without inadequate compensatory enlargement (group B, n = 30) as determined by IVUS. The acute results and the follow-up lumen dimensions of angiographically successful directional coronary atherectomy procedures were compared. Inadequate compensatory enlargement was considered present when the preintervention arterial cross-sectional area at the target lesion site was smaller than that at the (distal) reference site. Three-dimensional IVUS analysis and quantitative angiography were performed in 46 patients before and after intervention. IVUS measurements included the arterial, lumen, and plaque (arterial minus lumen) cross-sectional areas at the target lesion site (i.e., smallest lumen site) and the (distal) reference site. Angiographic follow-up was performed in 42 patients. Preintervention and postintervention angiographic measurements and IVUS lumen cross-sectional area measurements were similar in both groups. However, at follow-up, the angiographic minimum lumen and reference diameters were significantly smaller in group A compared with group B (1.71 ± 0.47 mm vs 2.14 ± 0.73 mm, p <0.03, and 2.97 ± 0.29 mm vs 3.39 ± 0.76 mm, p <0.02; group A vs B). The data of this observational study suggest that lesions with inadequate compensatory enlargement, as determined by IVUS before intervention, may have less favorable long-term lumen dimensions after directional coronary atherectomy procedures.