Resumo Fundamento A avaliação do Escore de Cálcio Coronariano (ECC) pode ser realizada por tomografia computadorizada sem contraste para prever eventos cardiovasculares, mas tem menor valor na ...estratificação de risco em pacientes sintomáticos. Objetivo Identificar e validar preditores de obstrução coronariana significativa (OCS) em pacientes sintomáticos sem calcificação da artéria coronária. Métodos Um total de 4258 participantes foram rastreados dos estudos CORE64 e CORE 320, nos quais foram avaliados pacientes encaminhados para angiografia invasiva, e do Quanta Registry que incluiu pacientes encaminhados para angiotomografia. Modelos de regressão logística avaliaram associações entre fatores de risco cardiovascular, ECC e OCS. Um nível de significância de 5% foi usado nas análises. Resultados Dos 509 participantes do estudo CORE, 117 (23%) apresentaram um ECC igual a zero; 13 (11%) pacientes sem cálcio coronariano apresentaram OCS. A ausência de cálcio coronariano correlacionou-se com idade mais jovem, sexo feminino, índice de massa corporal mais baixo, ausência de diabetes, e ausência de dislipidemia. O fato de ser fumante atual aumentou em 3,5 vezes a probabilidade de OCS e outros fatores de risco cardiovasculares não apresentaram associação significativa. Considerando os achados clínicos, um algoritmo para estratificar os pacientes com ECC igual a zero foi proposto, e tiveram desempenho limitado na coorte de validação (AUC 58; IC95% 43, 72). Conclusão Um perfil de risco cardiovascular mais baixo está associado a um ECC igual a zero em pacientes de alto risco. Tabagismo é o preditor mais forte de OCS em pacientes com ausência de cálcio coronariano.
Aims
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).
Methods and results
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.
Conclusions
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.
The accuracy of multidetector computed tomographic (CT) angiography involving 64 detectors has not been well established.
We conducted a multicenter study to examine the accuracy of 64-row, 0.5-mm ...multidetector CT angiography as compared with conventional coronary angiography in patients with suspected coronary artery disease. Nine centers enrolled patients who underwent calcium scoring and multidetector CT angiography before conventional coronary angiography. In 291 patients with calcium scores of 600 or less, segments 1.5 mm or more in diameter were analyzed by means of CT and conventional angiography at independent core laboratories. Stenoses of 50% or more were considered obstructive. The area under the receiver-operating-characteristic curve (AUC) was used to evaluate diagnostic accuracy relative to that of conventional angiography and subsequent revascularization status, whereas disease severity was assessed with the use of the modified Duke Coronary Artery Disease Index.
A total of 56% of patients had obstructive coronary artery disease. The patient-based diagnostic accuracy of quantitative CT angiography for detecting or ruling out stenoses of 50% or more according to conventional angiography revealed an AUC of 0.93 (95% confidence interval CI, 0.90 to 0.96), with a sensitivity of 85% (95% CI, 79 to 90), a specificity of 90% (95% CI, 83 to 94), a positive predictive value of 91% (95% CI, 86 to 95), and a negative predictive value of 83% (95% CI, 75 to 89). CT angiography was similar to conventional angiography in its ability to identify patients who subsequently underwent revascularization: the AUC was 0.84 (95% CI, 0.79 to 0.88) for multidetector CT angiography and 0.82 (95% CI, 0.77 to 0.86) for conventional angiography. A per-vessel analysis of 866 vessels yielded an AUC of 0.91 (95% CI, 0.88 to 0.93). Disease severity ascertained by CT and conventional angiography was well correlated (r=0.81; 95% CI, 0.76 to 0.84). Two patients had important reactions to contrast medium after CT angiography.
Multidetector CT angiography accurately identifies the presence and severity of obstructive coronary artery disease and subsequent revascularization in symptomatic patients. The negative and positive predictive values indicate that multidetector CT angiography cannot replace conventional coronary angiography at present. (ClinicalTrials.gov number, NCT00738218.)
Objectives This study was designed to evaluate whether the absence of coronary calcium could rule out ≥50% coronary stenosis or the need for revascularization. Background The latest American Heart ...Association guidelines suggest that a calcium score (CS) of zero might exclude the need for coronary angiography among symptomatic patients. Methods A substudy was made of the CORE64 (Coronary Evaluation Using Multi-Detector Spiral Computed Tomography Angiography Using 64 Detectors) multicenter trial comparing the diagnostic performance of 64-detector computed tomography to conventional angiography. Patients clinically referred for conventional angiography were asked to undergo a CS scan up to 30 days before. Results In all, 291 patients were included, of whom 214 (73%) were male, and the mean age was 59.3 ± 10.0 years. A total of 14 (5%) patients had low, 218 (75%) had intermediate, and 59 (20%) had high pre-test probability of obstructive coronary artery disease. The overall prevalence of ≥50% stenosis was 56%. A total of 72 patients had CS = 0, among whom 14 (19%) had at least 1 ≥50% stenosis. The overall sensitivity for CS = 0 to predict the absence of ≥50% stenosis was 45%, specificity was 91%, negative predictive value was 68%, and positive predictive value was 81%. Additionally, revascularization was performed in 9 (12.5%) CS = 0 patients within 30 days of the CS. From a total of 383 vessels without any coronary calcification, 47 (12%) presented with ≥50% stenosis; and from a total of 64 totally occluded vessels, 13 (20%) had no calcium. Conclusions The absence of coronary calcification does not exclude obstructive stenosis or the need for revascularization among patients with high enough suspicion of coronary artery disease to be referred for coronary angiography, in contrast with the published recommendations. Total coronary occlusion frequently occurs in the absence of any detectable calcification. (Coronary Evaluation Using Multi-Detector Spiral Computed Tomography Angiography Using 64 Detectors CORE-64; NCT00738218 )
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.
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.
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.
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.
Purpose To compare the prognostic importance (time to major adverse cardiovascular event MACE) of combined computed tomography (CT) angiography and CT myocardial stress perfusion imaging with that of ...combined invasive coronary angiography (ICA) and stress single photon emission CT myocardial perfusion imaging. Materials and Methods This study was approved by all institutional review boards, and written informed consent was obtained. Between November 2009 and July 2011, 381 participants clinically referred for ICA and aged 45-85 years were enrolled in the Combined Noninvasive Coronary Angiography and Myocardial Perfusion Imaging Using 320-Detector Row Computed Tomography (CORE320) prospective multicenter diagnostic study. All images were analyzed in blinded independent core laboratories, and a panel of physicians adjudicated all adverse events. MACE was defined as revascularization (>30 days after index ICA), myocardial infarction, or cardiac death; hospitalization for chest pain or congestive heart failure; or arrhythmia. Late MACE was defined similarly, except for patients who underwent revascularization within the first 182 days after ICA, who were excluded. Comparisons of 2-year survival (time to MACE) used standard Kaplan-Meier curves and restricted mean survival times bootstrapped with 2000 replicates. Results An MACE (49 revascularizations, five myocardial infarctions, one cardiac death, nine hospitalizations for chest pain or congestive heart failure, and one arrhythmia) occurred in 51 of 379 patients (13.5%). The 2-year MACE-free rates for combined CT angiography and CT perfusion findings were 94% negative for coronary artery disease (CAD) versus 82% positive for CAD and were similar to combined ICA and single photon emission CT findings (93% negative for CAD vs 77% positive for CAD, P < .001 for both). Event-free rates for CT angiography and CT perfusion versus ICA and single photon emission CT for either positive or negative results were not significantly different for MACE or late MACE (P > .05 for all). The area under the receiver operating characteristic curve (AUC) for combined CT angiography and CT perfusion (AUC = 68; 95% confidence interval CI: 62, 75) was similar (P = .36) to that for combined ICA and single photon emission CT (AUC = 71; 95% CI: 65, 79) in the identification of MACE at 2-year follow-up. Conclusion Combined CT angiography and CT perfusion enables similar prediction of 2-year MACE, late MACE, and event-free survival similar to that enabled by ICA and single photon emission CT.
RSNA, 2017 Online supplemental material is available for this article.
Coronary MDCT angiography has been shown to be an accurate noninvasive tool for the diagnosis of obstructive coronary artery disease (CAD). Its sensitivity and negative predictive value for ...diagnosing percentage of stenosis are unsurpassed compared with those of other noninvasive testing methods. However, in its current form, it provides no information regarding the physiologic impact of CAD and is a poor predictor of myocardial ischemia. CORE320 is a multicenter multinational diagnostic study with the primary objective to evaluate the diagnostic accuracy of 320-MDCT for detecting coronary artery luminal stenosis and corresponding myocardial perfusion deficits in patients with suspected CAD compared with the reference standard of conventional coronary angiography and SPECT myocardial perfusion imaging.
We aim to describe the CT acquisition, reconstruction, and analysis methods of the CORE320 study.
The purpose of this study was to assess the impact of patient population characteristics on accuracy by computed tomography angiography (CTA) to detect obstructive coronary artery disease (CAD).
The ...ability of CTA to exclude obstructive CAD in patients of different pre-test probabilities and in presence of coronary calcification remains uncertain.
For the CORE-64 (Coronary Artery Evaluation Using 64-Row Multidetector Computed Tomography Angiography) study, 371 patients underwent CTA and cardiac catheterization for the detection of obstructive CAD, defined as ≥50% luminal stenosis by quantitative coronary angiography (QCA). This analysis includes 80 initially excluded patients with a calcium score ≥600. Area under the receiver-operating characteristic curve (AUC) was used to evaluate CTA diagnostic accuracy compared to QCA in patients according to calcium score and pre-test probability of CAD.
Analysis of patient-based quantitative CTA accuracy revealed an AUC of 0.93 (95% confidence interval CI: 0.90 to 0.95). The AUC remained 0.93 (95% CI: 0.90 to 0.96) after excluding patients with known CAD but decreased to 0.81 (95% CI: 0.71 to 0.89) in patients with calcium score ≥600 (p = 0.077). While AUCs were similar (0.93, 0.92, and 0.93, respectively) for patients with intermediate, high pre-test probability for CAD, and known CAD, negative predictive values were different: 0.90, 0.83, and 0.50, respectively. Negative predictive values decreased from 0.93 to 0.75 for patients with calcium score <100 or ≥100, respectively (p = 0.053).
Both pre-test probability for CAD and coronary calcium scoring should be considered before using CTA for excluding obstructive CAD. For that purpose, CTA is less effective in patients with calcium score ≥600 and in patients with a high pre-test probability for obstructive CAD.
Objectives This study sought to investigate the clinical and imaging characteristics associated with diagnostic inaccuracy of computed tomography angiography (CTA) for detecting obstructive coronary ...artery disease (CAD) defined by quantitative coronary angiography (QCA). Background Although diagnostic performance metrics of CTA have been reported, there are sparse data on predictors of diagnostic inaccuracy by CTA. Methods The clinical characteristics of 291 patients (mean age: 59 ± 10 years; female: 25.8%) enrolled in the multicenter CorE-64 (Coronary Artery Evaluation Using 64-Row Multi-detector Computed Tomography Angiography) study were examined. Pre-defined CTA segment-level characteristics of all true-positive (N = 237), false-positive (N = 115), false-negative (FN) (N = 159), and a random subset of true-negative segments (N = 511) for ≥50% stenosis with QCA as the reference standard were blindly abstracted in a central core laboratory. Factors independently associated with corresponding levels of CTA diagnostic inaccuracies on a patient level and coronary artery segment level were determined using multivariable logistic regression models and generalized estimating equations, respectively. Results An Agatston calcium score of ≥1 per patient (odds ratio OR: 5.2; 95% confidence interval CI: 1.1 to 24.6) and the presence of within-segment calcification (OR: 10.2; 95% CI: 5.2 to 19.8) predicted false-positive diagnoses. Conversely, absence of within-segment calcification was an independent predictor of an FN diagnosis (OR: 2.0; 95% CI: 1.2 to 3.5). Prior percutaneous revascularization was independently associated with patient-level misdiagnosis of obstructive CAD (OR: 4.2; 95% CI: 1.6 to 11.2). Specific segment characteristics on CTA, notably segment tortuosity (OR: 3.5; 95% CI: 2.4 to 5.1), smaller luminal caliber (OR: 0.48; 95% CI: 0.36 to 0.63 per 1-mm increment), and juxta-arterial vein conspicuity (OR: 2.1; 95% CI: 1.4 to 3.2), were independently associated with segment-level misdiagnoses. Attaining greater intraluminal contrast enhancement independently lowered the risk of an FN diagnosis (OR: 0.96; 95% CI: 0.94 to 0.99 per 10-Hounsfield unit increment). Conclusions We identified clinical and readily discernible imaging characteristics on CTA predicting inaccurate CTA diagnosis of obstructive CAD defined by QCA. Knowledge and appropriate considerations of these features may improve the diagnostic accuracy in clinical CTA interpretation. (Diagnostic Accuracy of Multi-Detector Spiral Computed Tomography Angiography Using 64 Detectors CORE-64; NCT00738218 )
Abstract Background 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. Objectives 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. Methods 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 defect by single photon emission CT. The combined CTA + CTP definition of disease was the presence of a ≥50% stenosis with a related perfusion defect. All data sets were analyzed by 2 experienced readers, aligning anatomic findings by CTA with perfusion defects by CTP. Results 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). Conclusions 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 defect.
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