Richard T George

Johns Hopkins University, Baltimore, Maryland, United States

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Publications (80)429.72 Total impact

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    ABSTRACT: Positive remodeling (PR), a coronary artery characteristic associated with risk for myocardial infarction (MI), may be more prevalent in HIV-infected (HIV+) people. We evaluated the prevalence of PR using coronary CT angiography (CCTA) in HIV+ and HIV-uninfected (HIV-) men. Men enrolled in the Multicenter AIDS Cohort Study underwent CCTA if they were 40-70 years, had normal kidney function and no history of coronary revascularization. Multivariable logistic regression models were used to estimate the odds ratio (OR) of PR by HIV serostatus, adjusting for demographics and coronary artery disease (CAD) risk factors. Analysis of PR among atherosclerotic segments further adjusted for plaque type and stenosis. The prevalence of PR was 8.4% versus 12.1% (p = 0.10) for HIV- and HIV + men, respectively. After demographic adjustment, HIV + men had twice the odds of PR [OR 2.01(95% CI 1.20-3.38)], which persisted after CAD risk factor adjustment [1.76(1.00-3.10)]. Higher systolic blood pressure, total cholesterol, diabetes medication use, older age, segment number with plaque present, mixed and non-calcified plaque, and stenosis>50%, were associated with increased odds of PR, while higher HDL cholesterol, higher nadir CD4 count, and black race were associated with lower PR odds. Among atherosclerotic segments, the association between HIV infection and PR persisted, but was not statistically significantly. HIV+ men have more positively remodeled arterial segments, which may be due to more coronary segments with atherosclerosis or HIV-related immunosuppression. Further studies are needed to evaluate whether PR contributes to higher rates of MI in HIV+ individuals. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
    Atherosclerosis 06/2015; 241(2):716-722. DOI:10.1016/j.atherosclerosis.2015.06.022 · 3.97 Impact Factor
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    ABSTRACT: Pilot study to determine whether among subjects receiving coronary computed tomography angiography (CTA), the combination of high-sensitivity troponin I (hsTnI) and coronary artery calcium score (CACS) identifies a low-risk population in whom CTA might be avoided. A cross-sectional study of 314 symptomatic patients receiving CTA as part of their acute coronary syndrome evaluation was conducted. hsTnI was measured with Abbott Laboratories' hsTnI assay. CACSs were calculated via the Agatston method. Patients were followed for at least 30 days after discharge for the occurrence of major adverse cardiac events (MACEs; all-cause mortality, acute coronary syndrome, and revascularization). Of 314 subjects studied, 213 (67.8%) had no coronary artery stenosis, and 67 (21.3%), 28 (8.9%), and 6 (1.9%) had maximal coronary artery stenosis of 1%-49%, 50%-69%, and 70% or greater, respectively. All MACEs occurred during index hospitalization and include one myocardial infarction and four revascularizations. Sixty-two percent (189/307) of subjects had zero CACS, and 24% (76/314) of subjects had undetected hsTnI. No subjects with undetectable hsTnI or zero CACS had an MACE. A strategy of avoiding further testing in subjects with undetectable initial hsTnI, performing CACS on subjects with detectable initial hsTnI but nonincreased hsTnI (less than 99th percentile), and obtaining CTA in subjects with Agatston greater than 0 will have a negative predictive value of 100.0% (95% confidence interval, 98.2%-100.0%). This strategy will avoid CTA in 63% (198/314) of subjects. In this pilot study, the addition of CACS to hsTnI improves the identification of low-risk subjects in whom CTA might be avoided. Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.
    Academic radiology 06/2015; DOI:10.1016/j.acra.2015.04.007 · 2.08 Impact Factor
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    ABSTRACT: HIV-infected individuals bear increased cardiovascular risk even in the absence of traditional cardiovascular risk factors. In the general population, coronary artery calcium (CAC) scanning is of value for cardiovascular risk stratification, but whether a CAC score of zero implies a low noncalcified coronary plaque burden in HIV-infected persons is unknown. We assessed the prevalence of noncalcified coronary plaque and compared noncalcified coronary plaque burden between HIV-infected and HIV-uninfected participants who had CAC scores of zero in the Multicenter AIDS Cohort Study (MACS) using coronary computed tomography (CT) angiography. HIV infection was associated with the presence of noncalcified coronary plaque among these men with CAC scores of zero. In a model adjusted only for age, race, centre, and pre- or post-2001 cohort, the prevalence ratio for the presence of noncalcified plaque was 1.27 (95% confidence interval 1.04-1.56; P = 0.02). After additionally adjusting for cardiovascular risk factors, HIV infection remained associated with the presence of noncalcified coronary plaque (prevalence ratio 1.31; 95% confidence interval 1.07-1.6; P = 0.01). Among men with CAC scores of zero, HIV infection is associated with an increased prevalence of noncalcified coronary plaque independent of traditional cardiovascular risk factors. This finding suggests that CAC scanning may underestimate plaque burden in HIV-infected men. © 2015 British HIV Association.
    HIV Medicine 05/2015; 63(12). DOI:10.1111/hiv.12262 · 3.45 Impact Factor
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    ABSTRACT: The purpose of this study was to develop a method for automatic and stable determination of the optimal time range for fitting with a Patlak plot model in order to measure myocardial perfusion using coronary X-ray angiography images. A conventional two-compartment model is used to measure perfusion, and the slope of the Patlak plot is calculated to obtain a perfusion image. The model holds for only a few seconds while the contrast agent flows from artery to myocardium. Therefore, a specific time range should be determined for fitting with the model. To determine this time range, automation is needed for routine examinations. The optimal time range was determined to minimize the standard error between data points and their least-squares regression straight line in the Patlak plot. A total of 28 datasets were tested in seven porcine models. The new method successfully detected the time range when contrast agent flowed from artery to myocardium. The mean cross correlation in the linear regression analysis (R(2)) was 0.996 ± 0.004. The mean length of the optimal time range was 3.61 ± 1.29 frames (2.18 ± 1.40 s). This newly developed method can automatically determine the optimal time range for fitting with the model.
    The international journal of cardiovascular imaging 04/2015; 31(5). DOI:10.1007/s10554-015-0658-2 · 2.32 Impact Factor
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    ABSTRACT: The combination of coronary CT angiography (CTA) and myocardial CT perfusion (CTP) is gaining increasing acceptance, but a standardized approach to be implemented in the clinical setting is necessary. To investigate the accuracy of a combined coronary CTA and myocardial CTP comprehensive protocol compared to coronary CTA alone, using a combination of invasive coronary angiography and single photon emission CT as reference. Three hundred eighty-one patients included in the CORE320 trial were analyzed in this study. Flow-limiting stenosis was defined as the presence of ≥50% stenosis by invasive coronary angiography with a related perfusion deficit by single photon emission CT. The combined CTA + CTP definition of disease was the presence of a ≥50% stenosis with a related perfusion deficit. All data sets were analyzed by 2 experienced readers, aligning anatomic findings by CTA with perfusion deficits by CTP. Mean patient age was 62 ± 6 years (66% male), 27% with prior history of myocardial infarction. In a per-patient analysis, sensitivity for CTA alone was 93%, specificity was 54%, positive predictive value was 55%, negative predictive value was 93%, and overall accuracy was 69%. After combining CTA and CTP, sensitivity was 78%, specificity was 73%, negative predictive value was 64%, positive predictive value was 0.85%, and overall accuracy was 75%. In a per-vessel analysis, overall accuracy of CTA alone was 73% compared to 79% for the combination of CTA and CTP (P < .0001 for difference). Combining coronary CTA and myocardial CTP findings through a comprehensive protocol is feasible. Although sensitivity is lower, specificity and overall accuracy are higher than assessment by coronary CTA when compared against a reference standard of stenosis with an associated perfusion deficit. Copyright © 2015 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.
    Journal of cardiovascular computed tomography 03/2015; DOI:10.1016/j.jcct.2015.03.004 · 4.51 Impact Factor
  • Radiology 02/2015; 274(2):626-626. DOI:10.1148/radiol.14144050 · 6.21 Impact Factor
  • Thura T Abd, Richard T George
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    ABSTRACT: Coronary computed tomography angiography (CTA) has been used increasingly for the diagnosis of coronary artery disease over the past decade. Compared to invasive coronary angiography (ICA), coronary CTA has the ability to visualize and quantify atherosclerotic plaque both calcified and non-calcified. Traditional measures of evaluating a coronary stenosis such as diameter stenosis, area stenosis, minimal lumen diameter and minimal luminal area are limited in their ability to predict its functional significance especially when diameter stenosis ranges between 30-69% (intermediate range). Measurement of invasive fractional flow reserve (FFR) is considered the gold standard for assessment of the hemodynamic significance of a stenosis. The current study by Nakazato et al. evaluates the performance of an emerging coronary CTA-derived anatomical measure "percent aggregate plaque volume" to improve the detection of hemodynamic significant stenosis as compared with invasive FFR.
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    ABSTRACT: Myocardial CT perfusion (CTP) is a promising tool for the detection of myocardial ischemia. We hypothesize that regadenoson CTP is noninferior to regadenoson single photon emission CT (SPECT) for detecting or excluding myocardial ischemia. Patients (men ≥45 years; women ≥50 years) with known or suspected coronary artery disease (n = 124) were randomized to 1 of 2 diagnostic sequences: rest and regadenoson SPECT on day 1, then regadenoson CTP and rest CTP (and coronary CT angiography [CTA]) (CTA; same acquisition) on day 2 or regadenoson CTP and rest CTP (and CTA) on Day 1, then rest and regadenoson SPECT on day 2. Scanning platforms included 64-, 128-, 256-, and 320-slice systems. The primary analysis examined the agreement rate between CTP and SPECT for detecting or excluding reversible ischemia in ≥2 myocardial segments as assessed by independent, blinded readers. Complete and interpretable CTP and SPECT scans were obtained for 110 patients. Regadenoson CTP was noninferior to SPECT for detecting or excluding reversible ischemia with an agreement rate of 0.87 (95% confidence interval [CI], 0.77-0.97) and sensitivity and specificity of 0.90 (95% CI, 0.71-1.00) and 0.84 (95% CI, 0.77-0.91), respectively. The agreement rate for detecting or excluding ≥1 fixed defects by regadenoson CTP and SPECT was 0.86 (95% CI, 0.74-0.98). With SPECT as the reference standard, the diagnostic accuracies for detecting or excluding ischemia by regadenoson CTP and CTA alone were 0.85 (95% CI, 0.78-0.91) and 0.69 (95% CI, 0.60-0.77), respectively. This study establishes the noninferiority of regadenoson CTP to SPECT for detecting or excluding myocardial ischemia. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.
    Journal of Cardiovascular Computed Tomography 01/2015; 9(2). DOI:10.1016/j.jcct.2015.01.002 · 4.51 Impact Factor
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    ABSTRACT: OBJECTIVE. The purpose of this study was to comprehensively study estimated radiation doses for subjects included in the main analysis of the Combined Non-invasive Coronary Angiography and Myocardial Perfusion Imaging Using 320 Detector Computed Tomography (CORE320) study ( identifier NCT00934037), a clinical trial comparing combined CT angiography (CTA) and perfusion CT with the reference standard catheter angiography plus myocardial perfusion SPECT. SUBJECTS AND METHODS. Prospectively acquired data on 381 CORE320 subjects were analyzed in four groups of testing related to radiation exposure. Radiation dose estimates were compared between modalities for combined CTA and perfusion CT with respect to covariates known to influence radiation exposure and for the main clinical outcomes defined by the trial. The final analysis assessed variations in radiation dose with respect to several factors inherent to the trial. RESULTS. The mean radiation dose estimate for the combined CTA and perfusion CT protocol (8.63 mSv) was significantly (p < 0.0001 for both) less than the average dose delivered from SPECT (10.48 mSv) and the average dose from diagnostic catheter angiography (11.63 mSv). There was no significant difference in estimated CTA-perfusion CT radiation dose for subjects who had false-positive or false-negative results in the CORE320 main analyses in a comparison with subjects for whom the CTA-perfusion CT findings were in accordance with the reference standard SPECT plus catheter angiographic findings. CONCLUSION. Radiation dose estimates from CORE320 support clinical implementation of a combined CT protocol for assessing coronary anatomy and myocardial perfusion.
    American Journal of Roentgenology 01/2015; 204(1):W27-36. DOI:10.2214/AJR.13.12375 · 2.74 Impact Factor
  • Wendy S Post, Richard T George, Matthew Budoff
    Annals of internal medicine 12/2014; 161(12):923-4. DOI:10.7326/L14-5033-2 · 16.10 Impact Factor
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    ABSTRACT: The aim of this study was to investigate the association of left ventricular mass (LVM) with coronary atherosclerosis and myocardial infarction (MI).
    European Heart Journal – Cardiovascular Imaging 11/2014; 16(2). DOI:10.1093/ehjci/jeu217 · 2.65 Impact Factor
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    ABSTRACT: Purpose To compare the diagnostic performance of myocardial computed tomographic (CT) perfusion imaging and single photon emission computed tomography (SPECT) perfusion imaging in the diagnosis of anatomically significant coronary artery disease (CAD) as depicted at invasive coronary angiography. Materials and Methods This study was approved by the institutional review board. Written informed consent was obtained from all patients. Sixteen centers enrolled 381 patients from November 2009 to July 2011. Patients underwent rest and adenosine stress CT perfusion imaging and rest and either exercise or pharmacologic stress SPECT before and within 60 days of coronary angiography. Images from CT perfusion imaging, SPECT, and coronary angiography were interpreted at blinded, independent core laboratories. The primary diagnostic parameter was the area under the receiver operating characteristic curve (Az). Sensitivity and specificity were calculated with use of prespecified cutoffs. The reference standard was a stenosis of at least 50% at coronary angiography as determined with quantitative methods. Results CAD was diagnosed in 229 of the 381 patients (60%). The per-patient sensitivity and specificity for the diagnosis of CAD (stenosis ≥50%) were 88% (202 of 229 patients) and 55% (83 of 152 patients), respectively, for CT perfusion imaging and 62% (143 of 229 patients) and 67% (102 of 152 patients) for SPECT, with Az values of 0.78 (95% confidence interval: 0.74, 0.82) and 0.69 (95% confidence interval: 0.64, 0.74) (P = .001). The sensitivity of CT perfusion imaging for single- and multivessel CAD was higher than that of SPECT, with sensitivities for left main, three-vessel, two-vessel, and one-vessel disease of 92%, 92%, 89%, and 83%, respectively, for CT perfusion imaging and 75%, 79%, 68%, and 41%, respectively, for SPECT. Conclusion The overall performance of myocardial CT perfusion imaging in the diagnosis of anatomic CAD (stenosis ≥50%), as demonstrated with the Az, was higher than that of SPECT and was driven in part by the higher sensitivity for left main and multivessel disease. © RSNA, 2014.
    Radiology 05/2014; 274(2):140806. DOI:10.1148/radiol.14140806 · 6.21 Impact Factor
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    ABSTRACT: Cytokines released by epicardial fat are implicated in the pathogenesis of atherosclerosis. HIV infection and antiretroviral therapy have been associated with changes in body fat distribution and coronary artery disease. We sought to determine whether HIV infection is associated with greater epicardial fat and whether epicardial fat is associated with subclinical coronary atherosclerosis. We studied 579 HIV-infected and 353 HIV-uninfected men aged 40-70 years with noncontrast computed tomography to measure epicardial adipose tissue (EAT) volume and coronary artery calcium (CAC). Total Plaque Score (TPS) and plaque subtypes (noncalcified, calcified, and mixed) were measured by coronary computed tomography angiography in 706 men. We evaluated the association between EAT and HIV serostatus, and the association of EAT with subclinical atherosclerosis, adjusting for age, race, and serostatus and with additional cardiovascular risk factors and tested for modifying effects of HIV serostatus. HIV-infected men had greater EAT than HIV-uninfected men (P = 0.001). EAT was positively associated with duration of antiretroviral therapy (P = 0.02), specifically azidothymidine (P < 0.05). EAT was associated with presence of any coronary artery plaque (P = 0.006) and noncalcified plaque (P = 0.001), adjusting for age, race, serostatus, and cardiovascular risk factors. Among men with CAC, EAT was associated with CAC extent (P = 0.006). HIV serostatus did not modify associations between EAT and either CAC extent or presence of plaque. Greater epicardial fat volume in HIV-infected men and its association with coronary plaque and antiretroviral therapy duration suggest potential mechanisms that might lead to increased risk for cardiovascular disease in HIV.
    AIDS (London, England) 05/2014; 28(11). DOI:10.1097/QAD.0000000000000116 · 6.56 Impact Factor
  • Journal of the American College of Cardiology 04/2014; 63(12):A2153. DOI:10.1016/S0735-1097(14)62156-2 · 15.34 Impact Factor
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    ABSTRACT: Coronary artery disease (CAD) has been associated with HIV infection, but data are not consistent. To determine whether HIV-infected men have more coronary atherosclerosis than uninfected men. Cross-sectional study. Multicenter AIDS Cohort Study. HIV-infected (n = 618) and uninfected (n = 383) men who have sex with men who were aged 40 to 70 years, weighed less than 136 kg (200 lb), and had no history of coronary revascularization. Presence and extent of coronary artery calcium (CAC) on noncontrast cardiac computed tomography (CT) and of any plaque; noncalcified, mixed, or calcified plaque; or stenosis on coronary CT angiography. 1001 men had noncontrast CT, of whom 759 had coronary CT angiography. After adjustment for age, race, CT scanning center, and cohort, HIV-infected men had a greater prevalence of CAC (prevalence ratio [PR], 1.21 [95% CI, 1.08 to 1.35]; P = 0.001) and any plaque (PR, 1.14 [CI, 1.05 to 1.24]; P = 0.001), including noncalcified (PR, 1.28 [CI, 1.13 to 1.45]; P < 0.001) and mixed (PR, 1.35 [CI, 1.10 to 1.65]; P = 0.004) plaque, than uninfected men. Associations between HIV infection and any plaque or noncalcified plaque remained significant (P < 0.005) after CAD risk factor adjustment. HIV-infected men had a greater extent of noncalcified plaque after CAD risk factor adjustment (P = 0.026). They also had a greater prevalence of coronary artery stenosis greater than 50% (PR, 1.48 [CI, 1.06 to 2.07]; P = 0.020), but not after CAD risk factor adjustment. Longer duration of highly active antiretroviral therapy (PR, 1.09 [CI, 1.02 to 1.17]; P = 0.007) and lower nadir CD4+ T-cell count (PR, 0.80 [CI, 0.69 to 0.94]; P = 0.005) were associated with coronary stenosis greater than 50%. Cross-sectional observational study design and inclusion of only men. Coronary artery plaque, especially noncalcified plaque, is more prevalent and extensive in HIV-infected men, independent of CAD risk factors. National Heart, Lung, and Blood Institute and National Institute of Allergy and Infectious Diseases.
    Annals of internal medicine 04/2014; 160(7):458-67. DOI:10.7326/M13-1754 · 16.10 Impact Factor
  • Rosco Gore, Theodore Abraham, Richard T George
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    ABSTRACT: We present a case that demonstrates myocardial fibrosis detected on a cardiac computed tomography study performed for the evaluation of chest pain in a patient with hypertrophic cardiomyopathy. We describe the correlation between echocardiographic strain imaging, quantitative positron emission tomography, and computed tomographic evidence of fibrosis and its implications in hypertrophic cardiomyopathy.
    Journal of cardiovascular computed tomography 03/2014; 8(2):166-9. DOI:10.1016/j.jcct.2013.12.019 · 4.51 Impact Factor
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    ABSTRACT: Transendocardial Stem Cell Injection (TESI) with mesenchymal stem cells improves remodeling in chronic ischemic cardiomyopathy, but the impact of the injection site remains unknown. To address whether TESI exerts its effects at the site of injection only or also in remote areas, we hypothesized that segmental myocardial scar and segmental ejection fraction improve to a greater extent in injected than in non-injected segments. Biplane ventriculographic and endocardial tracings were recorded. TESI was guided to 10 sites in infarct-border zones. Sites were mapped according to the 17-myocardial segment model. As a result, 510 segments were analyzed in 30 patients before and 13-months after TESI. Segmental early enhancement defect (SEED, a measure of scar size) was reduced by TESI in both injected (-43.7±4.4%, n=95, p<0.01) and non-injected segments (-25.1±7.8%, n=148, p<0.001; between group comparison p<0.05). Conversely, segmental ejection fraction (SEF, a measure of contractility) improved in injected scar segments (19.9±3.3 to 26.3±3.5%, p=0.003) but not in non-injected scar segments (21.3±2.6 to 23.5±3.2%, p=0.20, between group comparison p<0.05). In the subgroup of scar segments with baseline SEF<20%, the SEF improvement was even greater in injected segments (12.1±1.2% to 19.9±2.7%, n=18, p=0.003) vs. non-injected segments (13.3±1.3% to 16.1±2.1%, n=15, p=0.05; between group comparison p<0.05). These findings illustrate a dichotomy in regional responses to TESI. Although scar reduction was evident at the site of TESI and remotely, ventricular functional responses occurred preferentially at the sites of TESI. Furthermore, improvement was greatest when segmental left ventricular dysfunction was severe.
    Circulation Research 01/2014; 114(8). DOI:10.1161/CIRCRESAHA.114.302854 · 11.09 Impact Factor
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    ABSTRACT: PURPOSE The conventional form of non-invasive testing by stress single photon emission computed tomography (SPECT) perfusion imaging is known to be less reliable in the presence of clinical situations associated with balanced ischemia. The international, multicenter CORE320 trial was designed to test a non invasive risk stratification approach using combined computed tomography angiography (CTA) and adenosine stress CT perfusion (CTP) imaging compared to the reference standards of combined stress SPECT perfusion imaging and invasive coronary angiography (ICA). This design allows for the head-to-head comparison of the two forms of stress perfusion imaging (CTP and SPECT) vs. the reference standard of ICA in a post-hoc manner. The purpose of this analysis was to examine the non-concordance of CTP and SPECT perfusion imaging among participants of the CORE320 trial and compare to percent stenosis by ICA. METHOD AND MATERIALS The international, multicenter CORE320 study enrolled 381 symptomatic patients referred for ICA. Prior to ICA, patients underwent rest CTA and adenosine stress CTP as well as SPECT perfusion imaging. CTA, CTP, ICA, and SPECT were all analyzed using parallel methods in blinded independent laboratories. As part of this post-hoc analysis, when SPECT and CTP showed discordant results, we compared these results to the reference standard ICA. ICA was defined as abnormal at the ≥ 50% diameter stenosis threshold. RESULTS A positive CTP with a negative SPECT study occurred in 113 of the 381 enrolled subjects. Compared to ICA, 62% (70 of 113) of these had single vessel disease or greater and 33% (36 of 113) had multi-vessel (≥ 2 vessels) or left main disease. Conversely, a negative CTP with a positive SPECT study occurred in 33 subjects Only 27% (9/33) of these had single vessel disease or greater and 15% (7/33) had multi-vessel disease (P=0.004). CONCLUSION These data suggest that in patients with discordant findings in CTP and SPECT, CTP imaging is more sensitive than SPECT imaging for the detection of anatomic coronary stenosis. The majority of positive CTP studies without concordant SPECT defects do, in fact, demonstrate single, multi-vessel or left main coronary artery disease. CLINICAL RELEVANCE/APPLICATION CT perfusion imaging is more accurate than SPECT perfusion in predicting significant coronary stenosis, by ICA.
    Radiological Society of North America 2013 Scientific Assembly and Annual Meeting; 12/2013
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    ABSTRACT: To evaluate the diagnostic power of integrating the results of computed tomography angiography (CTA) and CT myocardial perfusion (CTP) to identify coronary artery disease (CAD) defined as a flow limiting coronary artery stenosis causing a perfusion defect by single photon emission computed tomography (SPECT). We conducted a multicentre study to evaluate the accuracy of integrated CTA-CTP for the identification of patients with flow-limiting CAD defined by ≥50% stenosis by invasive coronary angiography (ICA) with a corresponding perfusion deficit on stress single photon emission computed tomography (SPECT/MPI). Sixteen centres enroled 381 patients who underwent combined CTA-CTP and SPECT/MPI prior to conventional coronary angiography. All four image modalities were analysed in blinded independent core laboratories. The prevalence of obstructive CAD defined by combined ICA-SPECT/MPI and ICA alone was 38 and 59%, respectively. The patient-based diagnostic accuracy defined by the area under the receiver operating characteristic curve (AUC) of integrated CTA-CTP for detecting or excluding flow-limiting CAD was 0.87 [95% confidence interval (CI): 0.84-0.91]. In patients without prior myocardial infarction, the AUC was 0.90 (95% CI: 0.87-0.94) and in patients without prior CAD the AUC for combined CTA-CTP was 0.93 (95% CI: 0.89-0.97). For the combination of a CTA stenosis ≥50% stenosis and a CTP perfusion deficit, the sensitivity, specificity, positive predictive, and negative predicative values (95% CI) were 80% (72-86), 74% (68-80), 65% (58-72), and 86% (80-90), respectively. For flow-limiting disease defined by ICA-SPECT/MPI, the accuracy of CTA was significantly increased by the addition of CTP at both the patient and vessel levels. The combination of CTA and perfusion correctly identifies patients with flow limiting CAD defined as ≥50 stenosis by ICA causing a perfusion defect by SPECT/MPI.
    European Heart Journal 11/2013; DOI:10.1093/eurheartj/eht488 · 14.72 Impact Factor

Publication Stats

2k Citations
429.72 Total Impact Points


  • 2006–2015
    • Johns Hopkins University
      • Department of Medicine
      Baltimore, Maryland, United States
  • 2008–2014
    • Johns Hopkins Medicine
      • • Division of Cardiology
      • • Department of Medicine
      Baltimore, Maryland, United States
  • 2012
    • Harvard University
      Cambridge, Massachusetts, United States
  • 2009–2011
    • Fujita Health University
      • • Faculty of Radiological Technology
      • • School of Health Sciences
      Nagoya, Aichi, Japan