Paul Schoenhagen

Coronary Plaque Classification With Intravascular Ultrasound Radiofrequency Data Analysis

Background—Atherosclerotic plaque stability is related to histological composition. However, current diagnostic tools do not allow adequate in vivo identification and characterization of plaques. Spectral analysis of backscattered intravascular ultrasound (IVUS) data has potential for real-time in vivo plaque classification. Methods and Results—Eighty-eight plaques from 51 left anterior descending coronary arteries were imaged ex vivo at physiological pressure with the use of 30-MHz IVUS transducers. After IVUS imaging, the arteries were pressure-fixed and corresponding histology was collected in matched images. Regions of interest, selected from histology, were 101 fibrous, 56 fibrolipidic, 50 calcified, and 70 calcified-necrotic regions. Classification schemes for model building were computed for autoregressive and classic Fourier spectra by using 75% of the data. The remaining data were used for validation. Autoregressive classification schemes performed better than those from classic Fourier spectra with accuracies of 90.4% for fibrous, 92.8% for fibrolipidic, 90.9% for calcified, and 89.5% for calcified-necrotic regions in the training data set and 79.7%, 81.2%, 92.8%, and 85.5% in the test data, respectively. Tissue maps were reconstructed with the use of accurate predictions of plaque composition from the autoregressive classification scheme. Conclusions—Coronary plaque composition can be predicted through the use of IVUS radiofrequency data analysis. Autoregressive classification schemes performed better than classic Fourier methods. These techniques allow real-time analysis of IVUS data, enabling in vivo plaque characterization.

Extent and Direction of Arterial Remodeling in Stable Versus Unstable Coronary Syndromes An Intravascular Ultrasound Study

BACKGROUND The morphological characteristics of coronary plaques in patients with stable versus unstable coronary syndromes have been described in vivo with intravascular ultrasound, but the relationship between arterial remodeling and clinical presentation is not well known. METHODS AND RESULTS We studied 85 patients with unstable and 46 patients with stable coronary syndromes using intravascular ultrasound before coronary intervention. The lesion site and a proximal reference site were analyzed. The remodeling ratio (RR) was defined as the ratio of the external elastic membrane (EEM) area at the lesion to that at the proximal reference site. Positive remodeling was defined as an RR >1.05 and negative remodeling as an RR <0.95. Plaque area (13.9+/-5.5 versus 11.1+/-4.8 mm(2); P=0.005), EEM area (16.1+/-6.2 versus 13.0+/-4.8 mm(2); P=0. 004), and the RR (1.06+/-0.2 versus 0.94+/-0.2; P=0.008) were significantly greater at target lesions in patients with unstable syndromes than in patients with stable syndromes. Positive remodeling was more frequent in unstable than in stable lesions (51. 8% versus 19.6%), whereas negative remodeling was more frequent in stable lesions (56.5% versus 31.8%) (P=0.001). CONCLUSIONS Positive remodeling and larger plaque areas were associated with unstable clinical presentation, whereas negative remodeling was more common in patients with stable clinical presentation. This association between the extent of remodeling and clinical presentation may reflect a greater tendency of plaques with positive remodeling to cause unstable coronary syndromes.

SCCT expert consensus document on computed tomography imaging before transcatheter aortic valve implantation (TAVI)/transcatheter aortic valve replacement (TAVR).

Computed tomography (CT) plays an important role in the workup of patients who are candidates for implantation of a catheter-based aortic valve, a procedure referred to as transcatheter aortic valve implantation (TAVI) or transcatheter aortic valve replacement (TAVR). Contrast-enhanced CT imaging provides information on the suitability of the peripheral access vessels to accommodate the relatively large sheaths necessary to introduce the prosthesis. CT imaging also provides accurate dimensions of the ascending aorta, aortic root, and aortic annulus which are of importance for prosthesis sizing, and initial data indicate that compared with echocardiographic sizing, CT-based sizing of the prosthesis may lead to better results for postprocedural aortic valve regurgitation. Finally, CT permits one to predict appropriate fluoroscopic projections which are oriented orthogonal to the aortic valve plane. This consensus document provides recommendations about the use of CT imaging in patients scheduled for TAVR/TAVI, including data acquisition, interpretation, and reporting.

Effect of Diabetes on Progression of Coronary Atherosclerosis and Arterial Remodeling A Pooled Analysis of 5 Intravascular Ultrasound Trials

OBJECTIVES Our goal was to characterize coronary atherosclerosis progression and arterial remodeling in diabetic patients. BACKGROUND The mechanisms that underlie adverse cardiovascular outcomes in diabetic patients have not been well characterized. METHODS A systematic analysis was performed in 2,237 subjects in randomized controlled studies of atherosclerosis progression. The pattern of arterial remodeling, extent of coronary atherosclerosis, and disease progression was compared in subjects with and without diabetes. RESULTS In association with more risk factors, diabetic patients demonstrated a greater percent atheroma volume (PAV) (40.2 +/- 0.9% vs. 37.5 +/- 0.8%, p < 0.0001) and total atheroma volume (TAV) (199.4 +/- 7.9 mm(3) vs. 189.4 +/- 7.1 mm(3), p = 0.03) on multivariate analysis. A stronger correlation was observed between PAV and glycated hemoglobin (r = 0.22, p = 0.0003) than fasting glucose (r = 0.09, p < 0.0001), although the difference just failed to meet statistical significance after controlling for study. Diabetic patients exhibited a smaller lumen (291.1 +/- 104.8 mm(3) vs. 306.5 +/- 108.2 mm(3), p = 0.005) but no difference in external elastic membrane (494.9 +/- 166.9 mm(3) vs. 498.8 +/- 167.2 mm(3), p = 0.61) volumes. More rapid progression of PAV (0.6 +/- 0.4% vs. 0.05 +/- 0.3%, p = 0.0001) and TAV (-0.6 +/- 2.5 mm(3) vs. -2.7 +/- 2.4 mm(3), p = 0.03) was observed in diabetic patients on multivariate analysis. Smaller external elastic membrane (482.5 +/- 160.7 mm(3) vs. 519.9 +/- 166.9 mm(3), p = 0.03) and lumen (276.0 +/- 100.3 mm(3) vs. 310.1 +/- 105.6 mm(3), p = 0.001) volumes were observed in diabetic patients treated with insulin despite the presence of a similar TAV (206.5 +/- 88.6 mm(3) vs. 209.9 +/- 90.2 mm(3), p = 0.84). Intensive low-density lipoprotein cholesterol lowering in patients improved the rate of plaque progression, but only to the level observed in nondiabetic patients with suboptimal lipid control. CONCLUSIONS Diabetes is accompanied by more extensive atherosclerosis and inadequate compensatory remodeling. Accelerated plaque progression, despite use of medical therapies, supports the need to develop new antiatherosclerotic strategies in diabetic patients.

American Society of Echocardiography Clinical Recommendations for Multimodality Cardiovascular Imaging of Patients with Pericardial Disease: Endorsed by the Society for Cardiovascular Magnetic Resonance and Society of Cardiovascular Computed Tomography

Allan L. Klein, MD, FASE, Chair, Suhny Abbara, MD, Deborah A. Agler, RCT, RDCS, FASE, Christopher P. Appleton, MD, FASE, Craig R. Asher, MD, Brian Hoit, MD, FASE, Judy Hung, MD, FASE, Mario J. Garcia, MD, Itzhak Kronzon, MD, FASE, Jae K. Oh, MD, FASE, E. Rene Rodriguez, MD, Hartzell V. Schaff, MD, Paul Schoenhagen,MD, Carmela D. Tan,MD, and Richard D.White, MD,Cleveland and Columbus, Ohio; Boston, Massachusetts; Weston, Florida; Scottsdale, Arizona; Rochester, Minnesota; Bronx and New York, New York

Extent of left ventricular scar predicts outcomes in ischemic cardiomyopathy patients with significantly reduced systolic function: a delayed hyperenhancement cardiac magnetic resonance study.

OBJECTIVES The objective of the study was to determine whether the extent of left ventricular scar, measured with delayed hyperenhancement cardiac magnetic resonance (DHE-CMR), predicts survival in patients with ischemic cardiomyopathy (ICM) and severely reduced left ventricular ejection fraction (LVEF). BACKGROUND Patients with ICM and reduced LVEF have poor survival. Such patients have a high myocardial scar burden. CMR is highly accurate in delineation of myocardial scar. METHODS We studied 349 patients (76% men) with severe ICM (>or=70% disease in >or=1 epicardial coronary, and mean LVEF of 24%) that underwent DHE-CMR (Siemens 1.5-T scanner, Erlangen, Germany), between 2003 and 2006. Scar (quantified as percentage of myocardium) was defined on DHE-MR images as an intensity >2 standard deviations above the viable myocardium. Transmurality score was semiquantitatively recorded in a 17-segment model as: 0 = no scar, 1 = 1% to 25% scar, 2 = 26% to 50%, 3 = 51% to 75%, and 4 = >75%. The LVEF, demographic data, risk factors, need for cardiac transplantation (CTx), and all-cause mortality were recorded. RESULTS The mean age and follow-up were 65 +/- 11 years and 2.6 +/- 1.2 years (median 2.4 years [1.1, 3.5]), respectively. There were 56 events (51 deaths and 5 CTx). Mean scar percentage and transmurality score were higher in patients with events versus those without (39 +/- 22 vs. 30 +/- 20, p = 0.003, and 9.7 +/- 5 vs. 7.8 +/- 5, p = 0.004). On Cox proportional hazard survival analysis, quantified scar was greater than the median (30% of total myocardium), and female gender predicted events (relative risk 1.75 [95% Confidence Interval: 1.02 to 3.03] and relative risk 1.83 [95% Confidence Interval: 1.06 to 3.16], respectively, both p = 0.03). CONCLUSIONS In patients with ICM and severely reduced LVEF, a greater extent of myocardial scar, delineated by DHE-CMR is associated with increased mortality or the need for cardiac transplantation, potentially aiding further risk-stratification.

Non-invasive assessment of plaque morphology and remodeling in mildly stenotic coronary segments: comparison of 16-slice computed tomography and intravascular ultrasound

BackgroundNon-invasive identification and characterization of mildly stenotic atherosclerotic lesions is an increasingly important focus of coronary imaging. DesignWe examined the accuracy of multi (16)-slice computed tomography (MSCT) for imaging of these lesions in comparison with intravascular ultrasound (IVUS). MaterialsMildly stenotic segments of the left coronary artery were identified by coronary angiography and analyzed using IVUS and contrast-enhanced MSCT. Independent reviewers evaluated the accuracy of MSCT for presence, composition and distribution of atherosclerotic plaque and remodeling response in comparison to IVUS using receiver operating characteristic (ROC) data analysis. ResultsOf 46 segments in 14 patients, diagnostic characterization by MSCT was possible in 37 (80.4%) segments. In these segments the accuracy of MSCT for identifying plaque presence, calcification, distribution and positive remodeling was consistently greater than 0.90 (reader 1) and 0.87 (reader 2). ConclusionState-of-the-art MSCT can accurately identify mildly stenotic coronary atherosclerosis and provide an assessment of morphology and remodeling response.

Determinants of arterial wall remodeling during lipid-lowering therapy : Serial intravascular ultrasound observations from the reversal of atherosclerosis with aggressive lipid lowering therapy (REVERSAL) trial

Background— Coronary plaque progression and instability are associated with expansive remodeling of the arterial wall. However, the remodeling response during plaque-stabilizing therapy and its relationship to markers of lipid metabolism and inflammation are incompletely understood. Methods and Results— Serial intravascular ultrasound (IVUS) data from the Reversal of Atherosclerosis with Aggressive Lipid Lowering Therapy (REVERSAL) trial were obtained during 18 months of intensive versus moderate lipid-lowering therapy. In a subgroup of 210 patients, focal coronary lesions with mild luminal narrowing were identified. Lumen area, external elastic membrane (EEM) area, and plaque area were determined at the lesion and proximal reference sites at baseline and during follow-up. The remodeling ratio (RR) was calculated by dividing the lesion EEM area by the reference EEM area. The relationship between the change in remodeling, change in plaque area, lipid profile, and inflammatory markers was examined. At the lesion site, a progression in plaque area (8.9±25.7%) and a decrease in the RR (−3.0±11.2%) occurred during follow-up. In multivariable analyses, the percentage change in plaque area (P<0.0001), baseline RR (P<0.0001), baseline lesion lumen area (0.019), logarithmic value of the change in high-sensitivity C-reactive protein (P=0.027), and hypertension at baseline (P=0.014) showed a significant, direct relation with the RR at follow-up. Lesion location in the right coronary artery (P=0.006), percentage change in triglyceride levels (P=0.049), and age (P=0.037) demonstrated a significant, inverse relation with the RR at follow-up. Changes in LDL cholesterol, HDL cholesterol, and treatment group demonstrated no significant associations. Conclusions— Constrictive remodeling of the arterial wall was observed during plaque-stabilizing therapy with statin medications and appears related to their antiinflammatory effects.

Pre-Procedural Imaging of Aortic Root Orientation and Dimensions: Comparison Between X-Ray Angiographic Planar Imaging and 3-Dimensional Multidetector Row Computed Tomography

OBJECTIVES We sought to examine whether contrast-enhanced multidetector row computed tomography (MDCT) allows prediction of X-ray angiographic planes for the root angiogram in the context of transcatheter aortic valve implantation. BACKGROUND Understanding of aortic root orientation relative to the body axis is critical for precise positioning of the stent/valve during transcatheter aortic valve implantation. METHODS Forty patients with severe aortic stenosis underwent conventional X-ray angiography and contrast-enhanced MDCT of the aortic root. Oblique MDCT images of the aortic root, corresponding to X-ray angiographic left anterior oblique (LA)/right anterior oblique (RAO) projections, were created. The cranial/caudal angulation was compared between angiographic and reformatted MDCT images. In addition, root diameter measurements were compared. RESULTS The cranial angulation in the LAO X-ray angiograms (mean LAO: 39+/- 8, n = 38) and matched MDCT images were not significantly different (cranial: 25 +/- 7 vs. 23 +/- 8; p = 0.214). There was a small but significant difference between the caudal angulation in the RAO angiogram (mean RAO: 25 +/- 5, n = 40) and matched CT images (caudal: 21 +/- 9 vs. 29 +/- 10; p = 0.002). The annulus diameter in the LAO projection was not significantly different between X-ray angiography and contrast-enhanced MDCT (2.3 +/- 0.3 vs. 2.4 +/- 0.3; p = 0.052), whereas there was a small but significant difference in the annulus diameter in RAO projections between angiography and MDCT (2.4 +/- 0.3 vs. 2.2 +/- 0.3; p = 0.029). CONCLUSIONS Pre-procedural contrast-enhanced MDCT imaging of the aortic root allows prediction of X-ray angiographic planes and contributes to planning of the transcatheter aortic valve implantation.

Prognostic utility of 64-slice computed tomography in patients with suspected but no documented coronary artery disease

AIMS Although multislice computed tomography (MSCT) detects obstructive coronary artery disease (CAD) with high diagnostic accuracy, there is a paucity of long-term prognostic data. We sought to assess the incremental prognostic value of 64-slice CT in patients with suspected but no documented CAD. METHODS AND RESULTS Coronary MSCT was performed on 227 individuals (61% men, mean age 54 +/- 12 years, 63% with intermediate pre-test probability) without documented CAD, referred for coronary evaluation. Coronary artery disease by MSCT was categorized as follows: none or mild CAD (<50%, n = 172), > or =50% in one vessel (n = 23), two vessels [or in the proximal left anterior descending (LAD), n = 12], and three vessels (or in two vessels including the proximal LAD or left main, n = 20). Baseline risk factors, length of follow-up, and major adverse cardiac events (MACE), including cardiac death, myocardial infarction (MI), and coronary revascularization were recorded. Over a mean follow-up of 2.3 +/- 0.8 years, there were 18 MACE [including four hard events (one cardiac death and three MIs)]. Also, patients with one or more vessel obstructive CAD had increased hard events compared with those with less than one-vessel disease (log-rank statistic P-value 0.01). One or more vessel obstructive CAD was a significant predictor of MACE on univariable and multivariable Cox proportional survival analysis [hazard ratios 29.1 (6.7-126.6) and 9.82 (3.58-27.01), respectively, both P < 0.0001]. In 172 patients, with no or mild CAD, there was 99% freedom from MACE during follow-up. CONCLUSION Multislice computed tomography-classified extent of CAD provides incremental prognostic information in patients with suspected but no documented CAD.