Brian K. Courtney

Impaired coronary vasodilation by magnetic resonance angiography is associated with advanced coronary artery calcification.

OBJECTIVES This study evaluated the hypothesis that impaired nitroglycerin (NTG)-induced coronary vasodilation is associated with advanced coronary atherosclerosis in asymptomatic older patients. BACKGROUND Atherosclerosis is associated with both structural and functional abnormalities of the vessel wall. Noninvasive functional measures of subclinical coronary atherosclerosis may help characterize high-risk subjects and guide preventive therapy. METHODS A total of 236 older patients (age 60 to 72 years, 33% female) without a history of cardiovascular disease were studied. Nitroglycerin-induced coronary vasodilation was measured by magnetic resonance angiography (MRA). Cross-sectional images of the right coronary artery were acquired before and 5 min after 0.4-mg sublingual NTG using a gated, breath-held spiral coronary MRA sequence (0.7-mm resolution). Quantitative analysis of the increase in cross-sectional area was performed in the 90% of patients (n = 212) with adequate image quality. Quantitation of coronary artery calcification (CAC) was performed by multidetector computed tomography using the Agatston method. RESULTS Forty patients (19%) had advanced CAC (> or =400). Coronary vasodilation to NTG was significantly impaired (p = 0.02) in patients with advanced CAC (median [interquartile range] = 15.9% [4.2% to 28.0%] vs. 21.5% [9.6% to 36.6%] for CAC <400). Importantly, NTG-induced coronary vasodilation remained independently associated with advanced CAC after multivariate analysis incorporating risk factors (p = 0.02) and other potential confounders (p = 0.04). There was no significant difference in coronary vasodilation between men and women, but few women (n = 3) had advanced CAC. CONCLUSIONS Impaired NTG-induced coronary vasodilation by MRA is associated with advanced coronary atherosclerosis in a community-based cohort of older asymptomatic subjects. Coronary MRA may provide a noninvasive functional assessment of subclinical coronary atherosclerosis.

Influence of plaque calcium on neointimal hyperplasia following bare metal and drug-eluting stent implantation

To examine the influence of vessel wall calcium on neointimal hyperplasia (NIH) following bare metal stent (BMS) and drug‐eluting stent (DES) implantation.

Validation of a thermographic guidewire for endoluminal mapping of atherosclerotic disease: An in vitro study

Temperature heterogeneity along the inner surface of an artery may be a surrogate marker of impending plaque rupture and has been associated with an increased likelihood of future coronary events. Initial studies using catheter‐based thermographic devices have demonstrated that the changes in temperature are subtle, while the effects of coronary flow on measured temperature have not yet been examined. A novel guidewire‐based system (ThermoCoil, Imetrx) designed to measure surface temperature in coronary arteries was used to study the effects of heat source intensity and flow on measured temperature. An in vitro model of a focal, eccentric, heat‐generating lesion demonstrated that a guidewire‐based system can detect changes in surface temperature with a precision of less than 0.08°C. In this model, temperature measurements increased linearly with source temperature and decreased with increases in flow by an exponent of −0.33 (P < 0.001 for both). Flow rates and heat source properties can significantly influence the measurement and interpretation of thermographic data. The incorporation of 2D thermographic images may contribute further to the characterization of metabolically active plaques likely to cause acute coronary syndromes. Catheter Cardiovasc Interv 2004;62:221–229.

Intravascular Ultrasound Results From the NEVO ResElution-I Trial A Randomized, Blinded Comparison of Sirolimus-Eluting NEVO Stents With Paclitaxel-Eluting Taxus Liberté Stents in De Novo Native Coronary Artery Lesions

Background— The NEVO sirolimus-eluting stent (NEVO SES) is a novel cobalt-chromium stent combining sirolimus release from reservoirs with bioabsorbable polymer to reduce spatial and temporal polymer exposure. The aim of this study was to assess the arterial response to the NEVO SES in a randomized, blinded comparison versus the surface-coated TAXUS Liberte paclitaxel-eluting stent (TAXUS Liberté PES) in human native coronary lesions using intravascular ultrasound (IVUS). Methods and Results— The NEVO ResElution-I IVUS substudy enrolled 100 patients (1:1 randomization). In addition to standard IVUS variables, uniformity of neointimal distribution within stents was evaluated in 3 dimensions by computing mean neointimal thickness within 12 equally spaced radial sectors on every 1-mm cross section along the stented segment. The NEVO SES showed significantly less neointimal proliferation (neointimal obstruction: 5.5±11.0% versus 11.5±9.7%, P=0.02), resulting in less late lumen area loss and smaller maximum cross-sectional narrowing at 6 months. The absolute variability of neointima distribution, assessed by the standard deviation of neointimal thickness within each stent, was significantly reduced with the NEVO SES compared with the TAXUS Liberté PES(0.04±0.04 mm versus 0.10±0.07 mm, P<0.0001). TAXUS Liberté PES showed significantly greater positive vessel remodeling than the NEVO SES (&Dgr;vessel volume index: 1.30±1.36 mm3/mm versus 0.36±0.63 mm3/mm, respectively, P=0.003). Conclusions— The NEVO SES with focal release of sirolimus from reservoirs achieved significantly greater and more consistent suppression of neointimal hyperplasia than the surface-coated TAXUS Liberté PES. This was associated with less positive remodeling and no increased morphological or morphometric abnormalities surrounding the stent or at the stent margins. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00714883.Background— The NEVO sirolimus-eluting stent (NEVO SES) is a novel cobalt-chromium stent combining sirolimus release from reservoirs with bioabsorbable polymer to reduce spatial and temporal polymer exposure. The aim of this study was to assess the arterial response to the NEVO SES in a randomized, blinded comparison versus the surface-coated TAXUS Liberte paclitaxel-eluting stent (TAXUS Liberte PES) in human native coronary lesions using intravascular ultrasound (IVUS). Methods and Results— The NEVO ResElution-I IVUS substudy enrolled 100 patients (1:1 randomization). In addition to standard IVUS variables, uniformity of neointimal distribution within stents was evaluated in 3 dimensions by computing mean neointimal thickness within 12 equally spaced radial sectors on every 1-mm cross section along the stented segment. The NEVO SES showed significantly less neointimal proliferation (neointimal obstruction: 5.5±11.0% versus 11.5±9.7%, P =0.02), resulting in less late lumen area loss and smaller maximum cross-sectional narrowing at 6 months. The absolute variability of neointima distribution, assessed by the standard deviation of neointimal thickness within each stent, was significantly reduced with the NEVO SES compared with the TAXUS Liberte PES(0.04±0.04 mm versus 0.10±0.07 mm, P <0.0001). TAXUS Liberte PES showed significantly greater positive vessel remodeling than the NEVO SES (Δvessel volume index: 1.30±1.36 mm3/mm versus 0.36±0.63 mm3/mm, respectively, P =0.003). Conclusions— The NEVO SES with focal release of sirolimus from reservoirs achieved significantly greater and more consistent suppression of neointimal hyperplasia than the surface-coated TAXUS Liberte PES. This was associated with less positive remodeling and no increased morphological or morphometric abnormalities surrounding the stent or at the stent margins. Clinical Trial Registration— URL: . Unique identifier: [NCT00714883][1]. [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT00714883&atom=%2Fcirccvint%2F4%2F2%2F146.atom

Right coronary wall CMR in the older asymptomatic advance cohort: positive remodeling and associations with type 2 diabetes and coronary calcium.

BackgroundCoronary wall cardiovascular magnetic resonance (CMR) is a promising noninvasive approach to assess subclinical atherosclerosis, but data are limited in subjects over 60 years old, who are at increased risk. The purpose of the study was to evaluate coronary wall CMR in an asymptomatic older cohort.ResultsCross-sectional images of the proximal right coronary artery (RCA) were acquired using spiral black-blood coronary CMR (0.7 mm resolution) in 223 older, community-based patients without a history of cardiovascular disease (age 60-72 years old, 38% female). Coronary measurements (total vessel area, lumen area, wall area, and wall thickness) had small intra- and inter-observer variabilities (r = 0.93~0.99, all p < 0.0001), though one-third of these older subjects had suboptimal image quality. Increased coronary wall thickness correlated with increased coronary vessel area (p < 0.0001), consistent with positive remodeling. On multivariate analysis, type 2 diabetes was the only risk factor associated with increased coronary wall area and thickness (p = 0.03 and p = 0.007, respectively). Coronary wall CMR measures were also associated with coronary calcification (p = 0.01-0.03).ConclusionsRight coronary wall CMR in asymptomatic older subjects showed increased coronary atherosclerosis in subjects with type 2 diabetes as well as coronary calcification. Coronary wall CMR may contribute to the noninvasive assessment of subclinical coronary atherosclerosis in older, at-risk patient groups.

Intraoperative handheld optical coherence tomography forward-viewing probe: physical performance and preliminary animal imaging

A prototype intraoperative hand-held optical coherence tomography (OCT) imaging probe was developed to provide micron resolution cross-sectional images of subsurface tissue during open surgery. This new ergonomic probe was designed based on electrostatically driven optical fibers, and packaged into a catheter probe in the form factor of clinically accepted Bayonet shaped neurosurgical probes. Optical properties of the probe were measured to have a ~20 μm spot size, 5 mm working distance and 4 mm field of view. Feasibility of this probe for structural and Doppler shift imaging was tested on porcine femoral blood vessel imaging.

Intravascular Ultrasound Results From the NEVO ResElution-I Trial

Background— The NEVO sirolimus-eluting stent (NEVO SES) is a novel cobalt-chromium stent combining sirolimus release from reservoirs with bioabsorbable polymer to reduce spatial and temporal polymer exposure. The aim of this study was to assess the arterial response to the NEVO SES in a randomized, blinded comparison versus the surface-coated TAXUS Liberte paclitaxel-eluting stent (TAXUS Liberté PES) in human native coronary lesions using intravascular ultrasound (IVUS). Methods and Results— The NEVO ResElution-I IVUS substudy enrolled 100 patients (1:1 randomization). In addition to standard IVUS variables, uniformity of neointimal distribution within stents was evaluated in 3 dimensions by computing mean neointimal thickness within 12 equally spaced radial sectors on every 1-mm cross section along the stented segment. The NEVO SES showed significantly less neointimal proliferation (neointimal obstruction: 5.5±11.0% versus 11.5±9.7%, P=0.02), resulting in less late lumen area loss and smaller maximum cross-sectional narrowing at 6 months. The absolute variability of neointima distribution, assessed by the standard deviation of neointimal thickness within each stent, was significantly reduced with the NEVO SES compared with the TAXUS Liberté PES(0.04±0.04 mm versus 0.10±0.07 mm, P<0.0001). TAXUS Liberté PES showed significantly greater positive vessel remodeling than the NEVO SES (&Dgr;vessel volume index: 1.30±1.36 mm3/mm versus 0.36±0.63 mm3/mm, respectively, P=0.003). Conclusions— The NEVO SES with focal release of sirolimus from reservoirs achieved significantly greater and more consistent suppression of neointimal hyperplasia than the surface-coated TAXUS Liberté PES. This was associated with less positive remodeling and no increased morphological or morphometric abnormalities surrounding the stent or at the stent margins. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00714883.Background— The NEVO sirolimus-eluting stent (NEVO SES) is a novel cobalt-chromium stent combining sirolimus release from reservoirs with bioabsorbable polymer to reduce spatial and temporal polymer exposure. The aim of this study was to assess the arterial response to the NEVO SES in a randomized, blinded comparison versus the surface-coated TAXUS Liberte paclitaxel-eluting stent (TAXUS Liberte PES) in human native coronary lesions using intravascular ultrasound (IVUS). Methods and Results— The NEVO ResElution-I IVUS substudy enrolled 100 patients (1:1 randomization). In addition to standard IVUS variables, uniformity of neointimal distribution within stents was evaluated in 3 dimensions by computing mean neointimal thickness within 12 equally spaced radial sectors on every 1-mm cross section along the stented segment. The NEVO SES showed significantly less neointimal proliferation (neointimal obstruction: 5.5±11.0% versus 11.5±9.7%, P =0.02), resulting in less late lumen area loss and smaller maximum cross-sectional narrowing at 6 months. The absolute variability of neointima distribution, assessed by the standard deviation of neointimal thickness within each stent, was significantly reduced with the NEVO SES compared with the TAXUS Liberte PES(0.04±0.04 mm versus 0.10±0.07 mm, P <0.0001). TAXUS Liberte PES showed significantly greater positive vessel remodeling than the NEVO SES (Δvessel volume index: 1.30±1.36 mm3/mm versus 0.36±0.63 mm3/mm, respectively, P =0.003). Conclusions— The NEVO SES with focal release of sirolimus from reservoirs achieved significantly greater and more consistent suppression of neointimal hyperplasia than the surface-coated TAXUS Liberte PES. This was associated with less positive remodeling and no increased morphological or morphometric abnormalities surrounding the stent or at the stent margins. Clinical Trial Registration— URL: . Unique identifier: [NCT00714883][1]. [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT00714883&atom=%2Fcirccvint%2F4%2F2%2F146.atom

Intravascular Ultrasound Results From the NEVO ResElution-I TrialClinical Perspective

Background— The NEVO sirolimus-eluting stent (NEVO SES) is a novel cobalt-chromium stent combining sirolimus release from reservoirs with bioabsorbable polymer to reduce spatial and temporal polymer exposure. The aim of this study was to assess the arterial response to the NEVO SES in a randomized, blinded comparison versus the surface-coated TAXUS Liberte paclitaxel-eluting stent (TAXUS Liberté PES) in human native coronary lesions using intravascular ultrasound (IVUS). Methods and Results— The NEVO ResElution-I IVUS substudy enrolled 100 patients (1:1 randomization). In addition to standard IVUS variables, uniformity of neointimal distribution within stents was evaluated in 3 dimensions by computing mean neointimal thickness within 12 equally spaced radial sectors on every 1-mm cross section along the stented segment. The NEVO SES showed significantly less neointimal proliferation (neointimal obstruction: 5.5±11.0% versus 11.5±9.7%, P=0.02), resulting in less late lumen area loss and smaller maximum cross-sectional narrowing at 6 months. The absolute variability of neointima distribution, assessed by the standard deviation of neointimal thickness within each stent, was significantly reduced with the NEVO SES compared with the TAXUS Liberté PES(0.04±0.04 mm versus 0.10±0.07 mm, P<0.0001). TAXUS Liberté PES showed significantly greater positive vessel remodeling than the NEVO SES (&Dgr;vessel volume index: 1.30±1.36 mm3/mm versus 0.36±0.63 mm3/mm, respectively, P=0.003). Conclusions— The NEVO SES with focal release of sirolimus from reservoirs achieved significantly greater and more consistent suppression of neointimal hyperplasia than the surface-coated TAXUS Liberté PES. This was associated with less positive remodeling and no increased morphological or morphometric abnormalities surrounding the stent or at the stent margins. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00714883.Background— The NEVO sirolimus-eluting stent (NEVO SES) is a novel cobalt-chromium stent combining sirolimus release from reservoirs with bioabsorbable polymer to reduce spatial and temporal polymer exposure. The aim of this study was to assess the arterial response to the NEVO SES in a randomized, blinded comparison versus the surface-coated TAXUS Liberte paclitaxel-eluting stent (TAXUS Liberte PES) in human native coronary lesions using intravascular ultrasound (IVUS). Methods and Results— The NEVO ResElution-I IVUS substudy enrolled 100 patients (1:1 randomization). In addition to standard IVUS variables, uniformity of neointimal distribution within stents was evaluated in 3 dimensions by computing mean neointimal thickness within 12 equally spaced radial sectors on every 1-mm cross section along the stented segment. The NEVO SES showed significantly less neointimal proliferation (neointimal obstruction: 5.5±11.0% versus 11.5±9.7%, P =0.02), resulting in less late lumen area loss and smaller maximum cross-sectional narrowing at 6 months. The absolute variability of neointima distribution, assessed by the standard deviation of neointimal thickness within each stent, was significantly reduced with the NEVO SES compared with the TAXUS Liberte PES(0.04±0.04 mm versus 0.10±0.07 mm, P <0.0001). TAXUS Liberte PES showed significantly greater positive vessel remodeling than the NEVO SES (Δvessel volume index: 1.30±1.36 mm3/mm versus 0.36±0.63 mm3/mm, respectively, P =0.003). Conclusions— The NEVO SES with focal release of sirolimus from reservoirs achieved significantly greater and more consistent suppression of neointimal hyperplasia than the surface-coated TAXUS Liberte PES. This was associated with less positive remodeling and no increased morphological or morphometric abnormalities surrounding the stent or at the stent margins. Clinical Trial Registration— URL: . Unique identifier: [NCT00714883][1]. [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT00714883&atom=%2Fcirccvint%2F4%2F2%2F146.atom

Attenuation Measurements of Optical Coherence Tomography Signals for the Assessment of Vascular Tissue Composition

Optical Coherence Tomography (OCT) has significant potential for assessing coronary artery disease. The OCT signal attenuation was measured in several arterial tissue types and may contribute to methods for classifying plaque composition and severity.