High rates of stent edge dissections were detected by OCT, usually related to the presence of atherosclerosis at stent edges and to PCI technique. Detailed OCT assessment of dissection severity was possible and affected the subsequent management of this complication. Non-flow-limiting, small, and superficial dissections left untreated proved benign.
FD-OCT assessment of ULM is feasible and safe. Direct comparisons with IVUS reveal that FD-OCT achieved imaging completeness less often, whereas it was more sensitive in detecting malapposition and edge dissections, and similar to IVUS in the assessment of lumen and stent dimensions.
Background
Persons living with HIV are at a higher risk of cardiovascular disease despite effective antiretroviral therapy and dramatic reductions in AIDS-related conditions. We sought to identify the epidemiology of heart failure (HF) among persons living with HIV in the United States in an era of contemporary antiretroviral therapy.
Methods
Explorys is an electronic healthcare database that aggregates medical records from 23 healthcare systems nationwide. Using systemized nomenclature of medicine - clinical terms (SNOMED-CT), we identified adult patients (age > 18), who had active records over the past year (September 2014–September 2015). We described the prevalence of HF in HIV patients by demographics and treatment and compared them to HIV-uninfected controls.
Results
Overall, there were 36,400 patients with HIV and 12,208,430 controls. The overall prevalence of HF was 7.2% in HIV and 4.4% in controls (RR 1.66 [1.60–1.72], p<0.0001). The relative risk of HF associated with HIV infection was higher among women and younger age groups. Patients receiving antiretroviral therapy had only marginally lower risk (6.4% vs 7.7%, p<0.0001) of HF compared to those who were untreated. Compared to uninfected patients with HF, HIV patients with HF were less likely to receive antiplatelet drugs, statins, diuretics, and ACE/ARBs (p<0.0001 for all comparisons). For patients with HIV and HF, receiving care from a cardiologist was associated with higher use of antiplatelets, statins, betablockers, ACE/ARBs, and diuretics.
Conclusions
Persons with HIV are at higher risk for HF in this large contemporary sample that includes both men and women. Although the prevalence of heart failure is higher in older HIV patients, the relative risk associated with HIV is highest in young people and in women. HIV patients are less likely to have HF optimally treated, but cardiology referral was associated with higher treatment rates.
Background-There are few clinical studies on the pathophysiological mechanisms of very late stent thrombosis (VLST).We report optical coherence tomography findings in patients with VLST and compare the findings between bare-metal stents (BMS) and drug-eluting stents (DES
Background
Coronary artery calcification (CAC) presents unique challenges for percutaneous coronary intervention. Calcium appears as a signal-poor region with well-defined borders by FD-OCT, which might enable full quantification of CAC. The objective of this study was to demonstrate the accuracy of intravascular frequency-domain optical coherence tomography (FD-OCT) to determine distribution of CAC.
Methods and Results
Cadaveric coronary arteries were imaged using FD-OCT at 100Dm frame interval. Arteries were subsequently frozen, sectioned and imaged in their entire length at 20Dm intervals using the Case Cryo-Imaging automated system™. Full volumetric co-registration between FD-OCT and cryo-images was performed. Calcium area, distance from lumen and angle were traced on every cross-section and volumetric quantification was performed offline using a dedicated algorithm.
Thirty left anterior descending (LAD) arteries were imaged by both FD-OCT and cryo-imaging. Of these, 13 vessels had a total of 55 plaques with calcification by cryo-imaging and FD-OCT identified 47 (85%) of these plaques. Quantitative analyses of 1285 cryo-images were compared with corresponding co-registered 257 FD-OCT images. Calcium distribution, represented by the calcium-lumen distance (depth) and the mean calcium angle, was similar with excellent correlation between FD-OCT and cryo-imaging respectively (calcium-lumen distance: 0.25±0.09mm vs. 0.26±0.12mm, p=0.742; R=0.90), (mean calcium angle: 35.33±21.86° vs. 39.68±26.61°, p=0.207; R=0.88). Volumetric quantification of CAC was possible by OCT; calcium volume was underestimated in large calcifications in which the abluminal plaque border could not be well visualized (3.11±2.14mm3 vs. 4.58±3.39mm3, p=0.001) in OCT vs. cryo respectively.
Conclusion
Intravascular FD-OCT can accurately characterize CAC distribution. OCT can quantify absolute calcium volume, but may underestimate calcium burden in large plaques with poorly defined abluminal borders.
We developed machine learning methods to identify fibrolipidic and fibrocalcific A-lines in intravascular optical coherence tomography (IVOCT) images using a comprehensive set of handcrafted features. We incorporated features developed in previous studies (e.g., optical attenuation and A-line peaks). In addition, we included vascular lumen morphology and three-dimensional (3-D) digital edge and texture features. Classification methods were developed using expansive datasets (∼7000 images), consisting of both clinical in-vivo images and an ex-vivo dataset, which was validated using 3-D cryo-imaging/histology. Conditional random field was used to perform 3-D classification noise cleaning of classification results. We tested various multiclass approaches, classifiers, and feature selection schemes and found that a three-class support vector machine with minimal-redundancy-maximal-relevance feature selection gave the best performance. We found that inclusion of our morphological and 3-D features improved overall classification accuracy. On a held-out test set consisting of >1700 images, we obtained an overall accuracy of 81.58%, with the following (sensitivity/ specificity) for each class: other (81.43/89.59), fibrolipidic (94.48/87.32), and fibrocalcific (74.82/95.28). The en-face views of classification results showed that automated classification easily captured the preponderance of a disease segment (e.g., a calcified segment had large regions of fibrocalcific classifications). Finally, we demonstrated proof-of-concept for streamlining A-line classification output with existing fibrolipidic and fibrocalcific boundary segmentation methods, to enable fully automated plaque quantification. The results suggest that our classification approach is a viable step toward fully automated IVOCT plaque classification and segmentation for live-time treatment planning and for offline assessment of drug and biologic therapeutics.
Optical coherence tomography has emerged as a powerful tool for stent assessment, and in a short time, has become the modality of choice for studying stent and vascular interactions in vivo. In this review, we discuss qualitative and quantitative parameters used for stent assessment by OCT. Various qualitative/quantitative variables of stent assessment are discussed in the perspective of the clinical and research values of each of them.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.