- Email: [email protected]
Atherosclerosis imaging: Virtual histology, remodeling and plaque rupture
THURSDAY 9/30/04 10:30
AM–12:00 PM
(Room 209A)
Atherosclerosis Imaging: Virtual Histology, Remodeling and Plaque Rupture
O R A L
Thursday, September 30, 2004 10:30 AM-12:00 PM Room 209A
A B S T R A C T S
(Abstract nos. 247-252)
Conclusion: Our in vivo IVUS-based virtual histology analysis demonstrates more fibrous plaque and less fibro-lipidic content in subjects with diabetes compared with control subjects.
TCT-247 A Comparison of Morphologic Features Between Patients with and Without Diabetes: A Virtual Histology Study. K. Fujii, Cardiovascular Research Foundation; S.G. Carlier, Cardiovascular Research Foundation; G.S. Mintz, Cardiovascular Research Foundation; W.Wijns, Cardiovascular Center OLV Hospital; A. Colombo, Centro Cuore Columbus; J.D.R. Costa Jr, Cardiovascular Research Foundation; H. Takebayashi, Cardiovascular Research Foundation; T. Yasuda, Cardiovascular Research Foundation; R.A. Costa, Cardiovascular Research Foundation; G.W. Stone, Cardiovascular Research Foundation; J.W. Moses, Cardiovascular Research Foundation; M.B. Leon, Cardiovascular Research Foundation. Background: Patients with diabetes have increased morbidity and more complications after intervention compared with patients without diabetes. However, few pathologic studies comparing the features of atherosclerotic plaques in patients with and without diabetes are available. The aim of this study was to evaluate coronary plaque morphology using spectral analysis of backscattered intravascular ultrasound (IVUS) in vivo. Methods: A total of 84 de novo native atherosclerotic plaques from 53 patients were imaged in vivo using 30-MHz IVUS transducers. The electrocardiographic-gated image acquisition and digitization was performed by a workstation designed for 3-dimensional reconstruction. In our system, the averaged spectrum from regions of interest (ROI) was computed and parameters identified within the bandwidth of 17 to 42 MHz from the spectrum normalized by the spectrum of an acrylic perfect reflector. A database of parameters was then used to compute a classification tree for plaque characterization. The values of radiofrequency signal from each ROI were classified into 4 plaque types: calcified; fibrous; fibro-lipidic; and necrotic core. The algorithms have been derived and validated in vitro. We divided the lesions into 2 groups: (1) diabetes group (16 lesions in 12 patients) and (2) nondiabetes group (68 lesions in 43 patients). Results: No significant differences existed in lumen area, external elastic membrane area, and plaque area at minimum lumen site and at both reference sites between the 2 groups. Averages of each plaque features within the lesion segment in both groups are shown in the Figure. The mean percent area of fibrous plaque was greater in subjects with diabetes compared with those without diabetes (p ⫽ 0.002), whereas the mean percent area of fibro-lipidic plaque was smaller in patients with diabetes (p ⫽ 0.02). Comparable morphologic features were obtained at the minimum lumen cross-sectional site.
The American Journal of Cardiology姞
TCT-248 Virtual Histology Reconstruction of Intravascular Ultrasound Imaging: In Vivo Correlation with Histology on Samples Obtained from Directional Atherectomy. I. Michev, San Raffaele Hospital; P. Margolis, The Cleveland Clinic Foundation; G. Vitrella, San Raffaele Hospital; I. Iakovou, San Raffaele Hospital; D.G. Vince, The Cleveland Clinic Foundation; A. Colombo, San Raffaele Hospital; F. Airoldi, San Raffaele Hospital; M.L. Gaddis, The Cleveland Clinic Foundation; A. Chieffo, San Raffaele Hospital. Background: Virtual HistologyTM intravascular ultrasound (IVUS) technology (Volcano Therapeutics) provides analytical determination of plaque components, using easily accessible IVUS backscattered radiofrequency (RF) signals. The analyzed RF information is used to reconstruct tissue maps and provide “virtual” histology information of the vessel wall and atherosclerotic plaque. The technique has been previously validated in a comparison between matched histology of ex vivo specimens. There are 4 possible basic tissue types in an atherosclerotic plaque that can be identified: (1) fibrosis, (2) fibro-lipidic, (3) calcified, (4) lipid necrotic. In the present study we sought to investigate the accuracy of in vivo IVUS with histology from atherectomy samples to identify atherosclerotic tissue components. Methods: After coronary angiography of the target lesion, an IVUS catheter was introduced distal to the plaque. The record was obtained using a 0.5-mm/sec pullback. During the pullback, both grayscale IVUS data and raw RF data were captured for VH analysis. Then, directional atherectomy (DCA) was performed at the narrowest region (minimum lumen diameter by IVUS) of the lesion. After the first cut, the tissue sample was extracted from the atherectomy device, prepared, and fixed in 10% formalin. IVUS interrogation was repeated. The histologic examinations were performed by operators unaware of the IVUS, angiographic, and clinical information. Results: A total of 5 lesions from 5 patients were analyzed; 2 patients had recent myocardial infarctions, 2 had unstable angina, and 1 had stable angina. Plaque composition according to virtual histology showed the following results: fibrosis (all lesions), fibro-lipidic (4 lesions); lipid necrosis (3 lesions). The histologic examination confirmed the presence of the same component in all the cases. Conclusion: The preliminary correlation between in vivo IVUS examination and histology is very promising. The results need to be confirmed on a larger scale. An additional study involving 40 patients is planned and will be under way shortly.
SEPTEMBER 30, 2004
TCT ABSTRACTS/Oral
115E
THURSDAY 9/30/04 10:30
O R A L A B S T R A C T S
TCT-249
(Room 209A)
TCT-250
Intravascular Ultrasound Assessment of Ulcerated Ruptured Plaques in Saphenous Vein Grafts. T. Yasuda, S. Carlier, G. S. Mintz, K. Fujii, H. Takebayashi, J.d.R. Costa Jr., R. Costa, K. Sano, M. Kimura, G.W. Stone, M.B. Leon, J.W. Moses. Cardiovascular Research Foundation. Background: Most acute coronary syndromes in native vessels are associated with ruptured plaques. However, intravascular ultrasound (IVUS) assessment of ulcerated ruptured plaques (URP) in saphenous vein grafts (SVG) has not been previously reported. Methods: In 159 IVUS interrogations of SVGs among 147 patients with angina pectoris or silent ischemia performed in our institution between January 1999 and March 2004, we detected with IVUS 12 lesions demonstrating URP (see Figure). These were compared with 46 non-URP SVG lesions imaged before any intervention. SVG wall area (outer border of whole SVG), external elastic membrane (EEM, when visible), and lumen area were measured at the minimal lumen area (MLA) and at proximal and distal references.
Results: There was no difference between the 2 groups at the proximal and distal references regarding plaque burden, lumen, and EEM dimensions (see Table). The URP area was 2.1 ⫾ 1.0 mm2. SVG area at the URP level was larger than in the control lesions (p ⫽ 0.003). Wall area at URP level was larger than in control lesions (p ⫽ 0.002), and the remodeling index was significantly larger for URP (p ⫽ 0.019).
Group Reference segment Lumen area (mm2) SVG area (mm2) Wall area (mm2) Lesion Lumen area (mm2) SVG area (mm2) Wall area (mm2) Remodeling Index Arc of calcium (°)
Ruptured Plaque (n ⴝ 12)
Control (n ⴝ 46)
p Value
10.2 ⫾ 2.5 21.5 ⫾ 4.1 10.4 ⫾ 3.3
10.6 ⫾ 4.5 20.3 ⫾ 7.1 11.2 ⫾ 3.9
NS NS NS
5.6 ⫾ 1.9 26.6 ⫾ 7.9 21.0 ⫾ 7.9 1.19 ⫾ 0.21 54 ⫾ 68
5.0 ⫾ 2.6 19.2 ⫾ 7.0 14.2 ⫾ 5.9 1.01 ⫾ 0.21 48 ⫾ 73
NS ⬍0.01 ⬍0.01 ⬍0.05 NS
NS ⫽ not significant. Conclusion: This is the first description of ulcerated ruptured plaques in SVGs. URP are found preferentially in positively remodeled vessels. This is similar to findings in native coronary arteries in which ruptured plaques are also associated with increased plaque burden and positive remodeling.
116E
AM–12:00 PM
The American Journal of Cardiology姞
Positive or Intermediate Remodeled Lesions Can Undergo Negative Remodeling After Simvastatin Therapy Assessed By Intravascular Ultrasound. L.O. Jensen, Department of Cardiology, Odense University Hospital, Odense, Denmark; P. Thayssen, Department of Cardiology, Odense University Hospital, Odense, Denmark; S.G. Carlier, Cardiovascular Research Foundation, New York, USA; K.E. Pedersen, Department of Cardiology, Odense University Hospital, Odense, Denmark; T. Haghfelt, Department of Cardiology, Odense University Hospital, Odense, Denmark. Background: Coronary artery remodeling is often described by an index obtained at a single time point describing the magnitude and direction of remodeling. Because direct evidence of remodeling can be derived only from serial changes in the external elastic membrane (EEM) cross-sectional area (CSA), intravascular ultrasound (IVUS) was performed at baseline and after simvastatin therapy to investigate if positive or intermediate remodeled lesions could undergo negative remodeling as a consequence of simvastatin therapy. Methods: In 39 male patients with hypercholesterolemia and a nonsignificant coronary artery lesion, IVUS during electrocardiographically triggered pullback was performed at baseline and after 12 months with patients receiving simvastatin 40 mg/day. The lesion site was the image slice with maximum plaque burden. The proximal and distal reference segments were the segments with smallest plaque burden within 5 mm proximal and distal to the lesion. The remodeling index (RI) was defined as lesion EEM CSA divided by mean reference EEM CSA. Positive remodeling was defined as an RI ⬎1.05, negative remodeling as an RI ⬍0.95, and intermediate remodeling as an RI between 0.95 and 1.05. Results: At baseline, 69.2% of lesions had either a positive or intermediate RI, and 30.8% had a negative RI. Baseline patient characteristics were similar in both groups. Plaque ⫹ media CSA reduction was accompanied by EEM CSA reduction after 12 months on simvastatin in patients with positive or intermediate RI, whereas neither plaque ⫹ media nor EEM CSA changed significantly in patients with negative RI. Overall changes in EEM CSA at the site with maximum plaque burden correlated significantly with changes in plaque ⫹ media CSA after simvastatin therapy (r ⫽ 0.822, p ⬍0.001). After patients received simvastatin for 12 months, there were significant reductions in total cholesterol of 31.8% (6.1 ⫾ 0.8 vs 4.2 ⫾ 0.7, p ⬍0.001) and low-density lipoprotein cholesterol of 45.1% (4.0 ⫾ 0.7 vs 2.2 ⫾ 0.6, p ⬍0.001). Please see Table.
Positive or Intermediate RI Baseline EEM lesion (mm2) Plaque ⫹ media lesion (mm2) Lumen lesion (mm2) Plaque burden lesion Plaque thickness (max, mm)
p
15.6 ⫾ 4.8 14.5 ⫾ 4.7 ⬍0.001 14.4 ⫾ 3.7 14.6 ⫾ 3.7 10.2 ⫾ 3.6 8.8 ⫾ 3.2 ⬍0.001 8.8 ⫾ 3.2 8.3 ⫾ 2.7
ns ns
5.7 ⫾ 2.7
p
Negative RI Follow-Up
5.4 ⫾ 2.2
Follow-Up
ns
Baseline
5.6 ⫾ 2.9
6.2 ⫾ 2.9 0.020
0.65 ⫾ 0.11 0.61 ⫾ 0.13
0.001 0.61 ⫾ 0.14 0.58 ⫾ 0.16 0.039
1.58 ⫾ 0.31 1.50 ⫾ 0.32
0.008 1.59 ⫾ 0.30 1.57 ⫾ 0.30
ns
ns ⫽ not significant Conclusion: Lipid-lowering therapy with simvastatin for 12 months induced negative remodeling in coronary arteries with positive or intermediate remodeled lesions.
SEPTEMBER 30, 2004
TCT ABSTRACTS/Oral
THURSDAY 9/30/04 10:30
AM–12:00 PM
(Room 209A)
TCT-251
TCT-252
Plaque Morphology: Usefulness of Virtual Angioscopy in Comparison with Intravascular Ultrasound. P. Carrascosa, Diagnostico Maipu; R. Gilkeson, University Hospitals of Cleveland; P. Garcia Merletti, Diagnostico Maipu; M. Vembar, Philips Medical Systems; J. Carrascosa, Diagnostico Maipu; C. Capunay, Diagnostico Maipu. Background: The aim of this study was to determine the usefulness of virtual coronary angioscopy (VCA) in the identification of plaque morphology in comparison with intravascular ultrasound (IVUS). Methods: A total of 20 patients were evaluated by multislice spiral computed tomography (MSCT) and IVUS. CTs were performed with a 4-row and 16-row CT scanners (Mx8000 and Brillance16; Philips Medical Systems) with slices of 1.3 mm and 0.8 mm collimation, respectively. Judkins technique was performed for all coronary interventions. IVUS was performed after digital angiography with a 3.2Fr 30-MHz coronary imaging catheter (Boston Scientific Corporation). Continuous images were received as the catheter was automatically pulled back (0.5 mm/sec) from the distal artery. The IVUS images were analyzed off-line, and each vessel was divided into segments of 10-mm length from their origin up to reach the vessel diameter of 2 mm, to ensure that identical segments and plaques were assessed by the 2 methods. To characterize the plaques, IVUS classified them as soft, fibrous, and calcified; whereas MSCT took the densitometry of each plaque in Hounsfield Units (HU). The mean and standard deviations of each type of plaque in HU were. Knowing this information, highlight window and level were created using the following formula: Range HU ⫽ level (min)—width/2, level (max)—width/2. CTs created 3-dimensional tissues for each type of plaque that were used to performed the VCA evaluation. IVUS and VCA classified the plaques as concentric and eccentric. The diagnostic accuracy of VCA was calculated for the characterization of plaque morphology. Results: In the detection of eccentric plaques, VCA showed a sensitivity of 77.8%, specificity of 88.9%, positive predictive value of 91.3%, and negative predictive value of 72.7%; whereas for the identification of concentric plaques, VCA showed a sensitivity of 88.9%, specificity of 77.8%, positive predictive value of 57%, and negative predictive value of 91.3%. Conclusion: VCA is an interesting reprocessing tool for the characterization of plaque morphology showing high sensitivity and specificity for both types of plaques.
The American Journal of Cardiology姞
Remodeling Characteristics of Minimally Diseased Coronary Arteries Are Consistent Along the Length of the Artery. C. Feldman, Brigham & Women’s Hospital; A.U. Coskun, Northeastern University; Y. Yeghiazarians, Brigham & Women’s Hospital; S. Kinlay, Brigham & Women’s Hospital; A. Wahle, University of Iowa; M.E. Olszewski, University of Iowa; J.D. Rossen, University of Iowa. M. Sonka, University of Iowa; J.J. Popma, Brigham & Women’s Hospital; J. Orav, Brigham & Women’s Hospital; R.E. Kuntz, Brigham & Women’s Hospital; P.H. Stone, Brigham & Women’s Hospital. Background: Most minimally diseased coronary arteries outwardly remodel to accommodate plaque growth. It is unknown whether this remodeling pattern is unique to the area of plaque or is characteristic of the entire artery. The purposes of our study were to determine whether the remodeling characteristics of an artery, as defined by the response of the external elastic membrane (EEM) to increases in plaque volume, were consistent along the length of the artery, and how that response varied among arteries. Methods: A total of 53 native arteries with obstructions ⬍50% in 40 patients were studied (19 left anterior descending coronary artery, 15 left circumflex coronary artery, 19 right coronary artery). Each artery was reconstructed in anatomically correct 3-dimensional space space by fusing intravascular ultrasound and biplane angiographic images. Cross-sectional area of lumen, EEM, and plaque were determined at 1.5-mm intervals perpendicular to the centerline. Mean lumen area of these minimally diseased vessels was taken as the reference area. Results: Segment length was 44.7 ⫾ 31.1 mm. For 49 of 53 segments (92%), the cross-sectional area of the EEM was proportional to plaque area making it possible to characterize the entire segment by the slope of the line of EEM versus plaque. The distribution of slopes shows that 54.2% appropriately remodel (slope between 0.75 and 1.25) so that lumen does not change with increasing plaque; 18.8% excessively remodel revealing a paradoxically increasing lumen with increasing plaque; 27.1% inadequately or negatively remodel. Conclusion: For minimally diseased coronary arteries, 92% can be characterized by the slope of the line of EEM versus plaque. In 18.8% of the arteries there is excessive outward remodeling, behavior that has been associated with plaque rupture and unstable syndromes; 27.1% show inadequate or negative remodeling, behavior associated with obstructive coronary disease. Characterization of remodeling may provide a way to predict the future course of disease in individual coronary arteries.
SEPTEMBER 30, 2004
TCT ABSTRACTS/Oral
117E
O R A L A B S T R A C T S
AM–12:00 PM
(Room 209A)
Atherosclerosis Imaging: Virtual Histology, Remodeling and Plaque Rupture
O R A L
Thursday, September 30, 2004 10:30 AM-12:00 PM Room 209A
A B S T R A C T S
(Abstract nos. 247-252)
Conclusion: Our in vivo IVUS-based virtual histology analysis demonstrates more fibrous plaque and less fibro-lipidic content in subjects with diabetes compared with control subjects.
TCT-247 A Comparison of Morphologic Features Between Patients with and Without Diabetes: A Virtual Histology Study. K. Fujii, Cardiovascular Research Foundation; S.G. Carlier, Cardiovascular Research Foundation; G.S. Mintz, Cardiovascular Research Foundation; W.Wijns, Cardiovascular Center OLV Hospital; A. Colombo, Centro Cuore Columbus; J.D.R. Costa Jr, Cardiovascular Research Foundation; H. Takebayashi, Cardiovascular Research Foundation; T. Yasuda, Cardiovascular Research Foundation; R.A. Costa, Cardiovascular Research Foundation; G.W. Stone, Cardiovascular Research Foundation; J.W. Moses, Cardiovascular Research Foundation; M.B. Leon, Cardiovascular Research Foundation. Background: Patients with diabetes have increased morbidity and more complications after intervention compared with patients without diabetes. However, few pathologic studies comparing the features of atherosclerotic plaques in patients with and without diabetes are available. The aim of this study was to evaluate coronary plaque morphology using spectral analysis of backscattered intravascular ultrasound (IVUS) in vivo. Methods: A total of 84 de novo native atherosclerotic plaques from 53 patients were imaged in vivo using 30-MHz IVUS transducers. The electrocardiographic-gated image acquisition and digitization was performed by a workstation designed for 3-dimensional reconstruction. In our system, the averaged spectrum from regions of interest (ROI) was computed and parameters identified within the bandwidth of 17 to 42 MHz from the spectrum normalized by the spectrum of an acrylic perfect reflector. A database of parameters was then used to compute a classification tree for plaque characterization. The values of radiofrequency signal from each ROI were classified into 4 plaque types: calcified; fibrous; fibro-lipidic; and necrotic core. The algorithms have been derived and validated in vitro. We divided the lesions into 2 groups: (1) diabetes group (16 lesions in 12 patients) and (2) nondiabetes group (68 lesions in 43 patients). Results: No significant differences existed in lumen area, external elastic membrane area, and plaque area at minimum lumen site and at both reference sites between the 2 groups. Averages of each plaque features within the lesion segment in both groups are shown in the Figure. The mean percent area of fibrous plaque was greater in subjects with diabetes compared with those without diabetes (p ⫽ 0.002), whereas the mean percent area of fibro-lipidic plaque was smaller in patients with diabetes (p ⫽ 0.02). Comparable morphologic features were obtained at the minimum lumen cross-sectional site.
The American Journal of Cardiology姞
TCT-248 Virtual Histology Reconstruction of Intravascular Ultrasound Imaging: In Vivo Correlation with Histology on Samples Obtained from Directional Atherectomy. I. Michev, San Raffaele Hospital; P. Margolis, The Cleveland Clinic Foundation; G. Vitrella, San Raffaele Hospital; I. Iakovou, San Raffaele Hospital; D.G. Vince, The Cleveland Clinic Foundation; A. Colombo, San Raffaele Hospital; F. Airoldi, San Raffaele Hospital; M.L. Gaddis, The Cleveland Clinic Foundation; A. Chieffo, San Raffaele Hospital. Background: Virtual HistologyTM intravascular ultrasound (IVUS) technology (Volcano Therapeutics) provides analytical determination of plaque components, using easily accessible IVUS backscattered radiofrequency (RF) signals. The analyzed RF information is used to reconstruct tissue maps and provide “virtual” histology information of the vessel wall and atherosclerotic plaque. The technique has been previously validated in a comparison between matched histology of ex vivo specimens. There are 4 possible basic tissue types in an atherosclerotic plaque that can be identified: (1) fibrosis, (2) fibro-lipidic, (3) calcified, (4) lipid necrotic. In the present study we sought to investigate the accuracy of in vivo IVUS with histology from atherectomy samples to identify atherosclerotic tissue components. Methods: After coronary angiography of the target lesion, an IVUS catheter was introduced distal to the plaque. The record was obtained using a 0.5-mm/sec pullback. During the pullback, both grayscale IVUS data and raw RF data were captured for VH analysis. Then, directional atherectomy (DCA) was performed at the narrowest region (minimum lumen diameter by IVUS) of the lesion. After the first cut, the tissue sample was extracted from the atherectomy device, prepared, and fixed in 10% formalin. IVUS interrogation was repeated. The histologic examinations were performed by operators unaware of the IVUS, angiographic, and clinical information. Results: A total of 5 lesions from 5 patients were analyzed; 2 patients had recent myocardial infarctions, 2 had unstable angina, and 1 had stable angina. Plaque composition according to virtual histology showed the following results: fibrosis (all lesions), fibro-lipidic (4 lesions); lipid necrosis (3 lesions). The histologic examination confirmed the presence of the same component in all the cases. Conclusion: The preliminary correlation between in vivo IVUS examination and histology is very promising. The results need to be confirmed on a larger scale. An additional study involving 40 patients is planned and will be under way shortly.
SEPTEMBER 30, 2004
TCT ABSTRACTS/Oral
115E
THURSDAY 9/30/04 10:30
O R A L A B S T R A C T S
TCT-249
(Room 209A)
TCT-250
Intravascular Ultrasound Assessment of Ulcerated Ruptured Plaques in Saphenous Vein Grafts. T. Yasuda, S. Carlier, G. S. Mintz, K. Fujii, H. Takebayashi, J.d.R. Costa Jr., R. Costa, K. Sano, M. Kimura, G.W. Stone, M.B. Leon, J.W. Moses. Cardiovascular Research Foundation. Background: Most acute coronary syndromes in native vessels are associated with ruptured plaques. However, intravascular ultrasound (IVUS) assessment of ulcerated ruptured plaques (URP) in saphenous vein grafts (SVG) has not been previously reported. Methods: In 159 IVUS interrogations of SVGs among 147 patients with angina pectoris or silent ischemia performed in our institution between January 1999 and March 2004, we detected with IVUS 12 lesions demonstrating URP (see Figure). These were compared with 46 non-URP SVG lesions imaged before any intervention. SVG wall area (outer border of whole SVG), external elastic membrane (EEM, when visible), and lumen area were measured at the minimal lumen area (MLA) and at proximal and distal references.
Results: There was no difference between the 2 groups at the proximal and distal references regarding plaque burden, lumen, and EEM dimensions (see Table). The URP area was 2.1 ⫾ 1.0 mm2. SVG area at the URP level was larger than in the control lesions (p ⫽ 0.003). Wall area at URP level was larger than in control lesions (p ⫽ 0.002), and the remodeling index was significantly larger for URP (p ⫽ 0.019).
Group Reference segment Lumen area (mm2) SVG area (mm2) Wall area (mm2) Lesion Lumen area (mm2) SVG area (mm2) Wall area (mm2) Remodeling Index Arc of calcium (°)
Ruptured Plaque (n ⴝ 12)
Control (n ⴝ 46)
p Value
10.2 ⫾ 2.5 21.5 ⫾ 4.1 10.4 ⫾ 3.3
10.6 ⫾ 4.5 20.3 ⫾ 7.1 11.2 ⫾ 3.9
NS NS NS
5.6 ⫾ 1.9 26.6 ⫾ 7.9 21.0 ⫾ 7.9 1.19 ⫾ 0.21 54 ⫾ 68
5.0 ⫾ 2.6 19.2 ⫾ 7.0 14.2 ⫾ 5.9 1.01 ⫾ 0.21 48 ⫾ 73
NS ⬍0.01 ⬍0.01 ⬍0.05 NS
NS ⫽ not significant. Conclusion: This is the first description of ulcerated ruptured plaques in SVGs. URP are found preferentially in positively remodeled vessels. This is similar to findings in native coronary arteries in which ruptured plaques are also associated with increased plaque burden and positive remodeling.
116E
AM–12:00 PM
The American Journal of Cardiology姞
Positive or Intermediate Remodeled Lesions Can Undergo Negative Remodeling After Simvastatin Therapy Assessed By Intravascular Ultrasound. L.O. Jensen, Department of Cardiology, Odense University Hospital, Odense, Denmark; P. Thayssen, Department of Cardiology, Odense University Hospital, Odense, Denmark; S.G. Carlier, Cardiovascular Research Foundation, New York, USA; K.E. Pedersen, Department of Cardiology, Odense University Hospital, Odense, Denmark; T. Haghfelt, Department of Cardiology, Odense University Hospital, Odense, Denmark. Background: Coronary artery remodeling is often described by an index obtained at a single time point describing the magnitude and direction of remodeling. Because direct evidence of remodeling can be derived only from serial changes in the external elastic membrane (EEM) cross-sectional area (CSA), intravascular ultrasound (IVUS) was performed at baseline and after simvastatin therapy to investigate if positive or intermediate remodeled lesions could undergo negative remodeling as a consequence of simvastatin therapy. Methods: In 39 male patients with hypercholesterolemia and a nonsignificant coronary artery lesion, IVUS during electrocardiographically triggered pullback was performed at baseline and after 12 months with patients receiving simvastatin 40 mg/day. The lesion site was the image slice with maximum plaque burden. The proximal and distal reference segments were the segments with smallest plaque burden within 5 mm proximal and distal to the lesion. The remodeling index (RI) was defined as lesion EEM CSA divided by mean reference EEM CSA. Positive remodeling was defined as an RI ⬎1.05, negative remodeling as an RI ⬍0.95, and intermediate remodeling as an RI between 0.95 and 1.05. Results: At baseline, 69.2% of lesions had either a positive or intermediate RI, and 30.8% had a negative RI. Baseline patient characteristics were similar in both groups. Plaque ⫹ media CSA reduction was accompanied by EEM CSA reduction after 12 months on simvastatin in patients with positive or intermediate RI, whereas neither plaque ⫹ media nor EEM CSA changed significantly in patients with negative RI. Overall changes in EEM CSA at the site with maximum plaque burden correlated significantly with changes in plaque ⫹ media CSA after simvastatin therapy (r ⫽ 0.822, p ⬍0.001). After patients received simvastatin for 12 months, there were significant reductions in total cholesterol of 31.8% (6.1 ⫾ 0.8 vs 4.2 ⫾ 0.7, p ⬍0.001) and low-density lipoprotein cholesterol of 45.1% (4.0 ⫾ 0.7 vs 2.2 ⫾ 0.6, p ⬍0.001). Please see Table.
Positive or Intermediate RI Baseline EEM lesion (mm2) Plaque ⫹ media lesion (mm2) Lumen lesion (mm2) Plaque burden lesion Plaque thickness (max, mm)
p
15.6 ⫾ 4.8 14.5 ⫾ 4.7 ⬍0.001 14.4 ⫾ 3.7 14.6 ⫾ 3.7 10.2 ⫾ 3.6 8.8 ⫾ 3.2 ⬍0.001 8.8 ⫾ 3.2 8.3 ⫾ 2.7
ns ns
5.7 ⫾ 2.7
p
Negative RI Follow-Up
5.4 ⫾ 2.2
Follow-Up
ns
Baseline
5.6 ⫾ 2.9
6.2 ⫾ 2.9 0.020
0.65 ⫾ 0.11 0.61 ⫾ 0.13
0.001 0.61 ⫾ 0.14 0.58 ⫾ 0.16 0.039
1.58 ⫾ 0.31 1.50 ⫾ 0.32
0.008 1.59 ⫾ 0.30 1.57 ⫾ 0.30
ns
ns ⫽ not significant Conclusion: Lipid-lowering therapy with simvastatin for 12 months induced negative remodeling in coronary arteries with positive or intermediate remodeled lesions.
SEPTEMBER 30, 2004
TCT ABSTRACTS/Oral
THURSDAY 9/30/04 10:30
AM–12:00 PM
(Room 209A)
TCT-251
TCT-252
Plaque Morphology: Usefulness of Virtual Angioscopy in Comparison with Intravascular Ultrasound. P. Carrascosa, Diagnostico Maipu; R. Gilkeson, University Hospitals of Cleveland; P. Garcia Merletti, Diagnostico Maipu; M. Vembar, Philips Medical Systems; J. Carrascosa, Diagnostico Maipu; C. Capunay, Diagnostico Maipu. Background: The aim of this study was to determine the usefulness of virtual coronary angioscopy (VCA) in the identification of plaque morphology in comparison with intravascular ultrasound (IVUS). Methods: A total of 20 patients were evaluated by multislice spiral computed tomography (MSCT) and IVUS. CTs were performed with a 4-row and 16-row CT scanners (Mx8000 and Brillance16; Philips Medical Systems) with slices of 1.3 mm and 0.8 mm collimation, respectively. Judkins technique was performed for all coronary interventions. IVUS was performed after digital angiography with a 3.2Fr 30-MHz coronary imaging catheter (Boston Scientific Corporation). Continuous images were received as the catheter was automatically pulled back (0.5 mm/sec) from the distal artery. The IVUS images were analyzed off-line, and each vessel was divided into segments of 10-mm length from their origin up to reach the vessel diameter of 2 mm, to ensure that identical segments and plaques were assessed by the 2 methods. To characterize the plaques, IVUS classified them as soft, fibrous, and calcified; whereas MSCT took the densitometry of each plaque in Hounsfield Units (HU). The mean and standard deviations of each type of plaque in HU were. Knowing this information, highlight window and level were created using the following formula: Range HU ⫽ level (min)—width/2, level (max)—width/2. CTs created 3-dimensional tissues for each type of plaque that were used to performed the VCA evaluation. IVUS and VCA classified the plaques as concentric and eccentric. The diagnostic accuracy of VCA was calculated for the characterization of plaque morphology. Results: In the detection of eccentric plaques, VCA showed a sensitivity of 77.8%, specificity of 88.9%, positive predictive value of 91.3%, and negative predictive value of 72.7%; whereas for the identification of concentric plaques, VCA showed a sensitivity of 88.9%, specificity of 77.8%, positive predictive value of 57%, and negative predictive value of 91.3%. Conclusion: VCA is an interesting reprocessing tool for the characterization of plaque morphology showing high sensitivity and specificity for both types of plaques.
The American Journal of Cardiology姞
Remodeling Characteristics of Minimally Diseased Coronary Arteries Are Consistent Along the Length of the Artery. C. Feldman, Brigham & Women’s Hospital; A.U. Coskun, Northeastern University; Y. Yeghiazarians, Brigham & Women’s Hospital; S. Kinlay, Brigham & Women’s Hospital; A. Wahle, University of Iowa; M.E. Olszewski, University of Iowa; J.D. Rossen, University of Iowa. M. Sonka, University of Iowa; J.J. Popma, Brigham & Women’s Hospital; J. Orav, Brigham & Women’s Hospital; R.E. Kuntz, Brigham & Women’s Hospital; P.H. Stone, Brigham & Women’s Hospital. Background: Most minimally diseased coronary arteries outwardly remodel to accommodate plaque growth. It is unknown whether this remodeling pattern is unique to the area of plaque or is characteristic of the entire artery. The purposes of our study were to determine whether the remodeling characteristics of an artery, as defined by the response of the external elastic membrane (EEM) to increases in plaque volume, were consistent along the length of the artery, and how that response varied among arteries. Methods: A total of 53 native arteries with obstructions ⬍50% in 40 patients were studied (19 left anterior descending coronary artery, 15 left circumflex coronary artery, 19 right coronary artery). Each artery was reconstructed in anatomically correct 3-dimensional space space by fusing intravascular ultrasound and biplane angiographic images. Cross-sectional area of lumen, EEM, and plaque were determined at 1.5-mm intervals perpendicular to the centerline. Mean lumen area of these minimally diseased vessels was taken as the reference area. Results: Segment length was 44.7 ⫾ 31.1 mm. For 49 of 53 segments (92%), the cross-sectional area of the EEM was proportional to plaque area making it possible to characterize the entire segment by the slope of the line of EEM versus plaque. The distribution of slopes shows that 54.2% appropriately remodel (slope between 0.75 and 1.25) so that lumen does not change with increasing plaque; 18.8% excessively remodel revealing a paradoxically increasing lumen with increasing plaque; 27.1% inadequately or negatively remodel. Conclusion: For minimally diseased coronary arteries, 92% can be characterized by the slope of the line of EEM versus plaque. In 18.8% of the arteries there is excessive outward remodeling, behavior that has been associated with plaque rupture and unstable syndromes; 27.1% show inadequate or negative remodeling, behavior associated with obstructive coronary disease. Characterization of remodeling may provide a way to predict the future course of disease in individual coronary arteries.
SEPTEMBER 30, 2004
TCT ABSTRACTS/Oral
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