Daniel Berman

Do Major Cardiovascular Outcomes in Patients With Stable Ischemic Heart Disease in the Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation Trial Differ by Healthcare System

Background—The Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE) trial enrolled patients from 3 distinct healthcare systems (HCSs) in North America. The primary aim of this study was to determine whether there is a treatment difference in cardiovascular outcomes by HCS. Methods and Results—The study population included 968 patients from the US Department of Veterans Affairs (VA), 386 from the US non-VA, and 931 from Canada with different comorbidities and prognoses. The primary outcome was all-cause mortality or nonfatal myocardial infarction (MI) during the median 4.6-year follow-up. Baseline demographics were similar between percutaneous coronary intervention and optimal medical therapy treatment groups within each HCS. After follow-up, the primary end point of total mortality and nonfatal MI was not statistically significant between percutaneous coronary intervention and optimal medical therapy, regardless of HCS: VA, 22.3% versus 21.9% (hazard ratio, 1.05; 95% CI, 0.80–1.38; P=0.95); US non-VA, 15.8% versus 21.8% (hazard ratio, 0.70; 95% CI, 0.43–1.12; P=0.24); Canadian HCS, 17.3% versus 13.5% (hazard ratio, 1.30; 95% CI, 0.93–1.83; P=0.17). The interaction between HCSs and treatment was not statistically significant. Long-term mortality was significantly higher in the VA system as a result of significantly greater comorbidity and worse left ventricular function. Conclusions—In the COURAGE trial, addition of percutaneous coronary intervention to optimal medical therapy did not improve 5-year survival or reduce MI or other major adverse cardiovascular events regardless of whether patients were Canadian or American or US veterans or nonveterans. Outcome differences were largely explained by differences in baseline characteristics known to affect long-term prognosis. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT00007657.

Multimodality imaging for transcatheter aortic valve replacement

Multimodality imaging for transcatheter aortic valve replacement / , Multimodality imaging for transcatheter aortic valve replacement / , کتابخانه دیجیتال جندی شاپور اهواز

Novel SPECT Technologies and Approaches in Cardiac Imaging

Recent novel approaches in myocardial perfusion single photon emission CT (SPECT) have been facilitated by new dedicated high-efficiency hardware with solid-state detectors and optimized collimators. New protocols include very low-dose (1 mSv) stress-only, two-position imaging to mitigate attenuation artifacts, and simultaneous dual-isotope imaging. Attenuation correction can be performed by specialized low-dose systems or by previously obtained CT coronary calcium scans. Hybrid protocols using CT angiography have been proposed. Image quality improvements have been demonstrated by novel reconstructions and motion correction. Fast SPECT acquisition facilitates dynamic flow and early function measurements. Image processing algorithms have become automated with virtually unsupervised extraction of quantitative imaging variables. This automation facilitates integration with clinical variables derived by machine learning to predict patient outcome or diagnosis. In this review, we describe new imaging protocols made possible by the new hardware developments. We also discuss several novel software approaches for the quantification and interpretation of myocardial perfusion SPECT scans.

Automated Detection of Contractile Abnormalities from Stress-Rest Motion Changes

Changes in myocardial function signatures such as wall motion and thickening are typically computed separately from myocardial perfusion SPECT (MPS) stress and rest studies to assess for stress-induced function abnormalities. The standard approach may suffer from the variability in contour placements and image orientation when subtle changes between stress and rest scans in motion and thickening are being evaluated. We have developed a new measure of regional change of function signature (motion and thickening) computed directly from registered stress and rest gated MPS data. In our novel approach, endocardial surfaces at the end-diastolic and end-systolic frames for stress and rest studies were registered by matching ventricular surfaces. Furthermore, we propose a new global registration method based on finding the optimal rotation for myocardial best ellipsoid fit to minimize the indexing disparities between two surfaces between stress and rest studies. Myocardial stress-rest function changes were computed and normal limits of change were determined as the mean and standard deviation of the training set for each polar sample. Normal limits were utilized to quantify the stress-rest function change for each polar map sample and the accumulated quantified function signature values were used for abnormality assessments in territorial regions. To evaluate the effectiveness of our novel method, we examined the agreements of our results against visual scores for motion change on vessel territorial regions obtained by human experts on a test group with 623 cases and were able to show that our detection method has a improved sensitivity on per vessel territory basis, compared to those obtained by human experts utilizing gated MPS data.

Nuclear Cardiology for Imaging the Effects of Therapy

Coronary artery revascularization and medical intervention have become powerful therapies in the management of ischemic heart disease. Although coronary angiography forms the basis for much of our existing therapies for patients with known coronary artery disease (CAD), its cost and invasive nature preclude its routine and frequent use in the evaluation of all patients. Furthermore, angiography provides predominantly anatomic assessments and does not standardly assess the physiologic significance of an individual coronary stenosis. Nuclear stress imaging, with its ability to provide information about the physiologic significance of stenoses and risk stratification of CAD patients, is ideally suited to provide supplementary information to assess patients after intervention.1–3