Publications by authors named "Tami Crabtree"

Article Synopsis
  • The study aimed to evaluate the effectiveness of coronary computed tomography angiography (CCTA) in assessing the risk of cardiovascular events through atherosclerotic plaque analysis in patients with ischemia.
  • Using quantitative computed tomography (AI-QCT), researchers analyzed plaque characteristics and examined their relationship to cardiovascular death or myocardial infarction over an average follow-up of 3.3 years.
  • Results showed that total plaque volume was the strongest predictor of adverse outcomes, and incorporating AI-QCT data improved predictive models beyond traditional risk factors.
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Agatston coronary artery calcium (CAC) score is a strong predictor of mortality. However, the relationship between CAC and quantitative calcified plaque volume (CPV), which is measured on coronary computed tomography angiography (CCTA), is not well understood. Furthermore, there is limited evidence evaluating the difference between CAC versus CPV and CAC versus total plaque volume (TPV) in predicting obstructive coronary artery disease (CAD).

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Background: Noninvasive stress testing is commonly used for detection of coronary ischemia but possesses variable accuracy and may result in excessive health care costs.

Objectives: This study aimed to derive and validate an artificial intelligence-guided quantitative coronary computed tomography angiography (AI-QCT) model for the diagnosis of coronary ischemia that integrates atherosclerosis and vascular morphology measures (AI-QCT) and to evaluate its prognostic utility for major adverse cardiovascular events (MACE).

Methods: A post hoc analysis of the CREDENCE (Computed Tomographic Evaluation of Atherosclerotic Determinants of Myocardial Ischemia) and PACIFIC-1 (Comparison of Coronary Computed Tomography Angiography, Single Photon Emission Computed Tomography [SPECT], Positron Emission Tomography [PET], and Hybrid Imaging for Diagnosis of Ischemic Heart Disease Determined by Fractional Flow Reserve) studies was performed.

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Background: In the last 15 years, large registries and several randomized clinical trials have demonstrated the diagnostic and prognostic value of coronary computed tomography angiography (CCTA). Advances in CT scanner technology and developments of analytic tools now enable accurate quantification of coronary artery disease (CAD), including total coronary plaque volume and low attenuation plaque volume. The primary aim of CONFIRM2, (Quantitative COroNary CT Angiography Evaluation For Evaluation of Clinical Outcomes: An InteRnational, Multicenter Registry) is to perform comprehensive quantification of CCTA findings, including coronary, non-coronary cardiac, non-cardiac vascular, non-cardiac findings, and relate them to clinical variables and cardiovascular clinical outcomes.

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Article Synopsis
  • AI-QCT (Artificial Intelligence Quantitative CT) is effective for identifying coronary plaque morphology, specifically low-density noncalcified plaque (LD-NCP), utilizing NIRS-IVUS (near-infrared spectroscopy-intravascular ultrasound) as a benchmark.
  • The study assessed 133 plaques from 47 patients, revealing AI-QCT's high accuracy (94%) and a strong correlation with IVUS metrics such as vessel area and plaque burden.
  • Results suggest that AI-QCT is a reliable tool for detecting significant LD-NCP, with a notable optimal volume threshold identified for improved diagnostic performance.
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Background: Coronary CT angiography (CCTA) is a first-line noninvasive imaging modality for evaluating coronary artery disease (CAD). Recent advances in CCTA technology enabled semi-automated detection of coronary arteries and atherosclerosis. However, there have been to date no large-scale validation studies of automated assessment of coronary atherosclerosis phenotype and coronary artery dimensions by artificial intelligence (AI) compared to current standard invasive imaging.

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It is unknown whether gender influences the atherosclerotic plaque characteristics (APCs) of lesions of varying angiographic stenosis severity. This study evaluated the imaging data of 303 symptomatic patients from the derivation arm of the CREDENCE (Computed TomogRaphic Evaluation of Atherosclerotic Determinants of Myocardial IsChEmia) trial, all of whom underwent coronary computed tomographic angiography and clinically indicated nonemergent invasive coronary angiography upon study enrollment. Index tests were interpreted by 2 blinded core laboratories, one of which performed quantitative coronary computed tomographic angiography using an artificial intelligence application to characterize and quantify APCs, including percent atheroma volume (PAV), low-density noncalcified plaque (LD-NCP), noncalcified plaque (NCP), calcified plaque (CP), lesion length, positive arterial remodeling, and high-risk plaque (a combination of LD-NCP and positive remodeling ≥1.

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Objective: Obesity is associated with all-cause mortality and cardiovascular disease (CVD). Visceral fat (VF) is an important CVD risk metric given its independent correlation with myocardial infarction and stroke. This study aims to clarify the relationship between the presence and severity of VF with the presence and severity of coronary artery plaque.

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Aims: We compared diagnostic performance, costs, and association with major adverse cardiovascular events (MACE) of clinical coronary computed tomography angiography (CCTA) interpretation versus semiautomated approach that use artificial intelligence and machine learning for atherosclerosis imaging-quantitative computed tomography (AI-QCT) for patients being referred for nonemergent invasive coronary angiography (ICA).

Methods: CCTA data from individuals enrolled into the randomized controlled Computed Tomographic Angiography for Selective Cardiac Catheterization trial for an American College of Cardiology (ACC)/American Heart Association (AHA) guideline indication for ICA were analyzed. Site interpretation of CCTAs were compared to those analyzed by a cloud-based software (Cleerly, Inc.

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Article Synopsis
  • Direct oral anticoagulants (DOACs) like apixaban and rivaroxaban potentially influence coronary plaque progression differently in patients with nonvalvular atrial fibrillation.
  • A study compared effects over 12 months using cardiac CT in 74 patients, observing that both drugs led to plaque progression but with notable differences in the extent of calcified plaque advancements.
  • Results indicated that apixaban had significantly lower progression of calcified plaque compared to rivaroxaban, with also notable changes in high-risk plaque characteristics.
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Objective: This study evaluates the relationship between atherosclerotic plaque characteristics (APCs) and angiographic stenosis severity in patients with and without diabetes. Whether APCs differ based on lesion severity and diabetes status is unknown.

Research Design And Methods: We retrospectively evaluated 303 subjects from the Computed TomogRaphic Evaluation of Atherosclerotic Determinants of Myocardial IsChEmia (CREDENCE) trial referred for invasive coronary angiography with coronary computed tomographic angiography (CCTA) and classified lesions as obstructive (≥50% stenosed) or nonobstructive using blinded core laboratory analysis of quantitative coronary angiography.

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Background: The difference between expert level (L3) reader and artificial intelligence (AI) performance for quantifying coronary plaque and plaque components is unknown.

Objective: This study evaluates the interobserver variability among expert readers for quantifying the volume of coronary plaque and plaque components on coronary computed tomographic angiography (CCTA) using an artificial intelligence enabled quantitative CCTA analysis software as a reference (AI-QCT).

Methods: This study uses CCTA imaging obtained from 232 patients enrolled in the CLARIFY (CT EvaLuation by ARtificial Intelligence For Atherosclerosis, Stenosis and Vascular MorphologY) study.

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Article Synopsis
  • The study offers a long-term analysis (10 years) of prostate SBRT outcomes, with a focus on low and intermediate-risk patients treated at 18 institutions.
  • Median PSA levels significantly dropped from 5.12 ng/mL to less than 0.1 ng/mL over time, with high rates of biochemical recurrence-free survival—100% in low-risk and around 68% for unfavorable intermediate-risk patients after 10 years.
  • While there was a slight increase in grade 2 urinary toxicity over the years, severe complications remained low, indicating that the treatment regimen (delivering 38 Gy in 4 fractions) is both safe and effective.
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Background: Adverse cardiovascular events are a significant cause of mortality in end-stage renal disease (ESRD) patients. High-risk plaque anatomy may be a significant contributor. However, their atherosclerotic phenotypes have not been described.

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Deep learning frameworks have been applied to interpretation of coronary CTA performed for coronary artery disease (CAD) evaluation. The purpose of our study was to compare the diagnostic performance of myocardial perfusion imaging (MPI) and coronary CTA with artificial intelligence quantitative CT (AI-QCT) interpretation for detection of obstructive CAD on invasive angiography and to assess the downstream impact of including coronary CTA with AI-QCT in diagnostic algorithms. This study entailed a retrospective post hoc analysis of the derivation cohort of the prospective 23-center Computed Tomographic Evaluation of Atherosclerotic Determinants of Myocardial Ischemia (CREDENCE) trial.

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Background: Atherosclerotic plaque characterization by coronary computed tomography angiography (CCTA) enables quantification of coronary artery disease (CAD) burden and type, which has been demonstrated as the strongest discriminant of future risk of major adverse cardiac events (MACE). To date, there are no clinically useful thresholds to assist with understanding a patient's disease burden and guide diagnosis and management, as there exists with coronary artery calcium (CAC) scoring. The purpose of this manuscript is to establish clinically relevant plaque stages and thresholds based on evidence from invasive angiographic stenosis (ICA) and fractional flow reserve (FFR) data.

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Article Synopsis
  • The study aims to evaluate how various factors, including CCTA scanning techniques and patient characteristics, affect the performance of AI-based software in detecting significant coronary artery blockages (≥50% stenosis).
  • CCTA is a non-invasive imaging technique beneficial for diagnosing coronary artery disease. The effectiveness of AI-QCT software in improving diagnostic outcomes is being assessed through analysis of data collected from 303 stable patients.
  • The analysis includes measuring the software's sensitivity, specificity, and accuracy by comparing its results with established QCA measurements, while exploring the impact of different scanning and patient-related parameters on these diagnostics.
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Objective: The study evaluates the relationship of coronary stenosis, atherosclerotic plaque characteristics (APCs) and age using artificial intelligence enabled quantitative coronary computed tomographic angiography (AI-QCT).

Methods: This is a post-hoc analysis of data from 303 subjects enrolled in the CREDENCE (Computed TomogRaphic Evaluation of Atherosclerotic Determinants of Myocardial IsChEmia) trial who were referred for invasive coronary angiography and subsequently underwent coronary computed tomographic angiography (CCTA). In this study, a blinded core laboratory analysing quantitative coronary angiography images classified lesions as obstructive (≥50%) or non-obstructive (<50%) while AI software quantified APCs including plaque volume (PV), low-density non-calcified plaque (LD-NCP), non-calcified plaque (NCP), calcified plaque (CP), lesion length on a per-patient and per-lesion basis based on CCTA imaging.

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CyberKnife SBRT is capable of producing dosimetry comparable to that created by HDR brachytherapy. Our original CyberKnife prostate SBRT schedule of 3,800 cGy/4 fractions ("high dose") was based upon favorable published prostate HDR brachytherapy experience. Subsequently, our trial was modified to allow a lower dose of 3,400 cGy/5 fractions ("moderate dose") in selected cases.

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Purpose: We evaluated the use of high dose-rate-like stereotactic body radiation therapy (SBRT) retreatment for biopsy-proven local persistence in prostate postradiation therapy, evaluating efficacy and toxicity.

Methods And Materials: From 2009 to 2018, 50 patients with biopsy-proven recurrent prostate cancer >2 years after prior treatment were retreated with a high dose-rate-like dose of 3400 cGy over 5 fractions. Previous radiation therapy dose measured 75.

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Background: Stereotactic body radiation therapy is an emerging treatment for prostate cancer (PC), with potential biological and oncologic advantages. A well-established radiation dosing schedule (38Gy in 4 fractions) has shown excellent long-term efficacy in high-dose-rate (HDR) brachytherapy.

Objective: To report 5-yr efficacy, toxicity, and quality-of-life (QOL) outcomes of a novel 4-d SBRT regimen.

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Objectives To evaluate the novel Phoenix Atherectomy System as percutaneous treatment of de novo and restenotic infrainguinal arterial lesions. Methods This prospective, multicenter, nonrandomized investigational device exemption trial was conducted across 16 US and German centers between August 2010 and April 2013. Intention-to-treat enrollment was 128 patients (mean age: 71.

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Purpose: To evaluate the safety and effectiveness of the Crux vena cava filter in patients at risk for pulmonary embolism (PE).

Materials And Methods: The Crux Biomedical Evaluation of the Crux Inferior Vena Cava Filter System trial was an international prospective, multicenter, single-arm clinical trial in 125 patients implanted with the Crux filter between June 2010 and June 2011. Follow-up was 180 days after filter placement and 30 days after filter retrieval.

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