Abstract Objectives The aim of this study was to investigate the individual and combined accuracy of dynamic computed tomography (CT) myocardial perfusion imaging (MPI) and computed tomography ...angiography (CTA) fractional flow reserve (FFR) for the identification of functionally relevant coronary artery disease (CAD). Background Coronary CTA has become an established diagnostic test for ruling out CAD, but it does not allow interpretation of the hemodynamic severity of stenotic lesions. Two recently introduced functional CT techniques are dynamic MPI and CTA FFR using computational fluid dynamics. Methods From 2 institutions, 74 patients (n = 62 men, mean age 61 years) planned for invasive angiography with invasive FFR measurement in 142 vessels underwent CTA imaging and dynamic CT MPI during adenosine vasodilation. A patient-specific myocardial blood flow index was calculated, normalized to remote myocardial global left ventricular blood flow. CTA FFR was computed using an on-site, clinician-operated application. Using binary regression, a single functional CT variable was created combining both CT MPI and CTA FFR. Finally, stepwise diagnostic work-up of CTA FFR with selective use of CT MPI was simulated. The diagnostic performance of CT MPI, CTA FFR, and CT MPI integrated with CTA FFR was evaluated using C statistics with invasive FFR, with a threshold of 0.80 as a reference. Results Sensitivity, specificity, and accuracy were 73% (95% confidence interval CI: 61% to 86%), 68% (95% CI: 56% to 80%), and 70% (95% CI: 62% to 79%) for CT MPI and 82% (95% CI: 72% to 92%), 60% (95% CI: 48% to 72%), and 70% (63% to 80%) for CTA FFR. For CT MPI integrated with CTA FFR, diagnostic accuracy was 79% (95% CI: 71% to 87%), with improvement of the area under the curve from 0.78 to 0.85 (p < 0.05). Accuracy of the stepwise approach was 77%. Conclusions CT MPI and CTA FFR both identify functionally significant CAD, with comparable accuracy. Diagnostic performance can be improved by combining the techniques. A stepwise approach, reserving CT MPI for intermediate CTA FFR results, also improves diagnostic performance while omitting nearly one-half of the population from CT MPI examinations.
Objectives This study sought to determine the diagnostic accuracy of 64-slice computed tomographic coronary angiography (CTCA) to detect or rule out significant coronary artery disease (CAD). ...Background CTCA is emerging as a noninvasive technique to detect coronary atherosclerosis. Methods We conducted a prospective, multicenter, multivendor study involving 360 symptomatic patients with acute and stable anginal syndromes who were between 50 and 70 years of age and were referred for diagnostic conventional coronary angiography (CCA) from September 2004 through June 2006. All patients underwent a nonenhanced calcium scan and a CTCA, which was compared with CCA. No patients or segments were excluded because of impaired image quality attributable to either coronary motion or calcifications. Patient-, vessel-, and segment-based sensitivities and specificities were calculated to detect or rule out significant CAD, defined as ≥50% lumen diameter reduction. Results The prevalence among patients of having at least 1 significant stenosis was 68%. In a patient-based analysis, the sensitivity for detecting patients with significant CAD was 99% (95% confidence interval CI: 98% to 100%), specificity was 64% (95% CI: 55% to 73%), positive predictive value was 86% (95% CI: 82% to 90%), and negative predictive value was 97% (95% CI: 94% to 100%). In a segment-based analysis, the sensitivity was 88% (95% CI: 85% to 91%), specificity was 90% (95% CI: 89% to 92%), positive predictive value was 47% (95% CI: 44% to 51%), and negative predictive value was 99% (95% CI: 98% to 99%). Conclusions Among patients in whom a decision had already been made to obtain CCA, 64-slice CTCA was reliable for ruling out significant CAD in patients with stable and unstable anginal syndromes. A positive 64-slice CTCA scan often overestimates the severity of atherosclerotic obstructions and requires further testing to guide patient management.
Objectives The purpose of this study was to investigate whether the use of a semiautomated plaque quantification algorithm (reporting volumetric and geometric plaque properties) provides additional ...prognostic value for the development of acute coronary syndromes (ACS) as compared with conventional reading from cardiac computed tomography angiography (CCTA). Background CCTA enables the visualization of coronary plaque characteristics, of which some have been shown to predict ACS. Methods A total of 1,650 patients underwent 64-slice CCTA and were followed up for ACS for a mean 26 ± 10 months. In 25 patients who had ACS and 101 random controls (selected from 993 patients with coronary artery disease but without coronary event), coronary artery disease was evaluated using conventional reading (calcium score, luminal stenosis, morphology), and then independently quantified using semiautomated software (plaque volume, burden area plaque area divided by vessel area times 100%, noncalcified percentage, attenuation, remodeling). Clinical risk profile was calculated with Framingham risk score (FRS). Results There were no significant differences in conventional reading parameters between controls and patients who had ACS. Semiautomated plaque quantification showed that compared to controls, ACS patients had higher total plaque volume (median: 94 mm3 vs. 29 mm3 ) and total noncalcified volume (28 mm3 vs. 4 mm3 , p ≤ 0.001 for both). In addition, per-plaque maximal volume (median: 56 mm3 vs. 24 mm3 ), noncalcified percentage (62% vs. 26%), and plaque burden (57% vs. 36%) in ACS patients were significantly higher (p < 0.01 for all). A receiver-operating characteristic model predicting for ACS incorporating FRS and conventional CCTA reading had an area under the curve of 0.64; a second model also incorporating semiautomated plaque quantification had an area under the curve of 0.79 (p < 0.05). Conclusions The semiautomated plaque quantification algorithm identified several parameters predictive for ACS and provided incremental prognostic value over clinical risk profile and conventional CT reading. The application of this tool may improve risk stratification in patients undergoing CCTA.
Abstract Background Familial hypercholesterolemia is typically caused by LDL receptor (LDLR) mutations that result in elevated levels of LDL cholesterol (LDL-C). In homozygous FH, the prevalence of ...aortic valve calcification (AoVC) reaches 100% and is often symptomatic. Objectives The objective of this study was to investigate the prevalence, extent, and risk-modifiers of AoVC in heterozygous FH (he-FH) that are presently unknown. Methods Asymptomatic patients with he-FH and 131 non-familial hypercholesterolemia controls underwent CT computed tomography calcium scoring. AoVC was defined as the presence of calcium at the aortic valve leaflets. The extent of AoVC was expressed in Agatston units, as the AoVC-score. We compared the prevalence and extent of AoVC between cases and controls. In addition, we investigated risk modifiers of AoVC, including the presence of LDLR mutations without residual function (LDLR-negative mutations), maximum untreated LDL-cholesterol (maxLDL), LDL-C, blood pressure, and coronary artery calcification (CAC). Results We included 145 asymptomatic patients with he-FH (93 men; mean age 52 ± 8 years) and 131 non-familial hypercholesterolemia controls. The prevalence (%) and AoVC-score (median, IQR) were higher in he-FH patients than in controls: 41%, 51 (9–117); and 21%, 21 (3–49) (p < 0.001 and p = 0.007). Age, untreated maxLDL, CAC, and diastolic blood pressure were independently associated with AoVC. LDLR-negative mutational he-FH was the strongest predictor of the AoVC-score (OR: 4.81; 95% CI: 2.22 to 10.40; p = <0.001). Conclusions Compared to controls, he-FH is associated with a high prevalence and a large extent of subclinical AoVC, especially in patients with LDLR-negative mutations, highlighting the critical role of LDL-C metabolism in AoVC etiology.
64-Slice Computed Tomography Coronary Angiography in Patients With High, Intermediate, or Low Pretest Probability of Significant Coronary Artery Disease W. Bob Meijboom, Carlos A. G. van Mieghem, ...Nico R. Mollet, Francesca Pugliese, Annick C. Weustink, Niels van Pelt, Filippo Cademartiri, Koen Nieman, Eric Boersma, Peter de Jaegere, Gabriel P. Krestin, Pim J. de Feyter We assessed the usefulness of 64-slice computed tomography (CT) coronary angiography to detect or rule out coronary artery disease (CAD) in patients with various estimated pretest probabilities. The estimated pretest probability of CAD in patients with high, intermediate, or low pretest probability was 87%, 53%, and 13%. The estimated post-test probability of a negative CT scan was 17%, 0%, and 0%, and of a positive CT scan was 96%, 88%, and 68%. Computed tomography coronary angiography is useful in symptomatic patients with low or intermediate estimated pretest probability of having CAD and does not provide additional diagnostic information in patients with a high estimated pretest probability.
Objectives This study sought to analyze the natural history of coronary atherosclerosis by multislice computed tomography (MSCT) and assess the serial changes in coronary plaque burden, lumen ...dimensions, and arterial remodeling. Background MSCT can comprehensively assess coronary atherosclerosis by combining lumen and plaque size parameters. Methods Thirty-two patients with acute coronary syndromes underwent 64-slice computed tomography angiography after percutaneous coronary intervention at baseline and after a median of 39 months. All patients received contemporary medical treatment. All available coronary segments in every subject were analyzed. The progression of atherosclerosis per segment and per patient was assessed by means of change in percent atheroma volume (PAV), change in normalized total atheroma volume (TAVnorm), and percent change in TAV (% change in TAV). Serial coronary remodeling was also assessed. Measures of lumen stenosis included percent diameter stenosis (%DS), minimum lumen diameter (MLD), percent area stenosis (%AS), and minimum lumen area (MLA). For each patient, the mean of all matched segments was calculated at the 2 time points. Clinical events at follow-up were documented. Results The PAV did not change significantly (−0.15 ± 3.64%, p = 0.72). The mean change in TAVnorm was 47.36 ± 143.24 mm3 (p = 0.071), and the % change in TAV was 6.7% (p = 0.029). The MLD and MLA increased by 0.15 mm (−0.09 to 0.24, p = 0.039) and 0.52 mm2 (−0.38 to 1.04, p = 0.034) respectively, which was accompanied by vessel enlargement, with 53% of the patients showing expansive positive remodeling. Patients with clinical events had a larger TAVnorm at baseline (969.72 mm3 vs. 810.77 mm3 , p = 0.010). Conclusions MSCT can assess the progression of coronary atherosclerosis and may be used for noninvasive monitoring of pharmacological interventions in coronary artery disease. (PROSPECT: An Imaging Study in Patients With Unstable Atherosclerotic Lesions; NCT00180466 )
At present, traditional risk factors are used to guide cardiovascular management of asymptomatic subjects. Intensified surveillance may be warranted in those identified as high risk of developing ...cardiovascular disease (CVD). This study aims to determine the prognostic value of coronary computed tomography (CT) angiography (CCTA) next to the coronary artery calcium score (CACS) in patients at high CVD risk without symptoms suspect for coronary artery disease (CAD). A total of 665 patients at high risk (mean age 56 ± 9 years, 417 men), having at least one important CVD risk factor (diabetes mellitus, familial hypercholesterolemia, peripheral artery disease, or severe hypertension) or a calculated European systematic coronary risk evaluation of >10% were included from outpatient clinics at 2 academic centers. Follow-up was performed for the occurrence of adverse events including all-cause mortality, nonfatal myocardial infarction, unstable angina, or coronary revascularization. During a median follow-up of 3.0 (interquartile range 1.3 to 4.1) years, adverse events occurred in 40 subjects (6.0%). By multivariate analysis, adjusted for age, gender, and CACS, obstructive CAD on CCTA (≥50% luminal stenosis) was a significant predictor of adverse events (hazard ratio 5.9 CI 1.3 to 26.1). Addition of CCTA to age, gender, plus CACS, increased the C statistic from 0.81 to 0.84 and resulted in a total net reclassification index of 0.19 (p <0.01). In conclusion, CCTA has incremental prognostic value and risk reclassification benefit beyond CACS in patients without CAD symptoms but with high risk of developing CVD.
Objectives This study sought to demonstrate the 5-year clinical and functional multislice computed tomography angiographic results after implantation of the fully resorbable everolimus-eluting ...scaffold (Absorb BVS, Abbott Vascular, Santa Clara, California). Background Multimodality imaging of the first-in-humans trial using a ABSORB BVS scaffold demonstrated at 2 years the bioresorption of the device while preventing restenosis. However, the long-term safety and efficacy of this therapy remain to be documented. Methods In the ABSORB cohort A trial (ABSORB Clinical Investigation, Cohort A ABSORB A Everolimus-Eluting Coronary Stent System Clinical Investigation), 30 patients with a single de novo coronary artery lesion were treated with the fully resorbable everolimus-eluting Absorb scaffold at 4 centers. As an optional investigation in 3 of the 4 centers, the patients underwent multislice computed tomography (MSCT) angiography at 18 months and 5 years. Acquired MSCT data were analyzed at an independent core laboratory (Cardialysis, Rotterdam, the Netherlands) for quantitative analysis of lumen dimensions and was further processed for calculation of fractional flow reserve (FFR) at another independent core laboratory (Heart Flow, Redwood City, California). Results Five-year clinical follow-up is available for 29 patients. One patient withdrew consent after 6 months, but the vital status of this patient remains available. At 46 days, 1 patient experienced a single episode of chest pain and underwent a target lesion revascularization with a slight troponin increase after the procedure. At 5 years, the ischemia-driven major adverse cardiac event rate of 3.4% remained unchanged. Clopidogrel was discontinued in all but 1 patient. Scaffold thrombosis was not observed in any patient. Two noncardiac deaths were reported, 1 caused by duodenal perforation and the other from Hodgkin’s disease. At 5 years, 18 patients underwent MSCT angiography. All scaffolds were patent, with a median minimal lumen area of 3.25 mm2 (interquartile range: 2.20 to 4.30). Noninvasive FFR analysis was feasible in 13 of 18 scans, which yielded a median distal FFR of 0.86 (interquartile range: 0.82 to 0.94). Conclusions The low event rate at 5 years suggests sustained safety after the implantation of a fully bioresorbable Absorb everolimus-eluting scaffold. Noninvasive assessment of the coronary artery with an option of functional assessment could be an alternative to invasive imaging after treatment of coronary narrowing with such a polymeric bioresorbable scaffold. (ABSORB Clinical Investigation, Cohort A ABSORB A Everolimus-Eluting Coronary Stent System Clinical Investigation ABSORB; NCT00300131 )
Highlights • With 4D flow, any plane of interest can be interactively chosen for quantitative measurements. • Anatomical and flow data is obtained during an approximately 10-minute free-breathing ...scan. • 4D CMR flow measurements correlated well with the 2D PC ones. • Eddy current correction is important for good results with 4D flow
Abstract Background It is uncertain whether a diagnostic strategy supplemented by early coronary computed tomography angiography (CCTA) is superior to contemporary standard optimal care (SOC) ...encompassing high-sensitivity troponin assays (hs-troponins) for patients suspected of acute coronary syndrome (ACS) in the emergency department (ED). Objectives This study assessed whether a diagnostic strategy supplemented by early CCTA improves clinical effectiveness compared with contemporary SOC. Methods In a prospective, open-label, multicenter, randomized trial, we enrolled patients presenting with symptoms suggestive of an ACS at the ED of 5 community and 2 university hospitals in the Netherlands. Exclusion criteria included the need for urgent cardiac catheterization and history of ACS or coronary revascularization. The primary endpoint was the number of patients identified with significant coronary artery disease requiring revascularization within 30 days. Results The study population consisted of 500 patients, of whom 236 (47%) were women (mean age 54 ± 10 years). There was no difference in the primary endpoint (22 9% patients underwent coronary revascularization within 30 days in the CCTA group and 17 7% in the SOC group p = 0.40). Discharge from the ED was not more frequent after CCTA (65% vs. 59%, p = 0.16), and length of stay was similar (6.3 h in both groups; p = 0.80). The CCTA group had lower direct medical costs (€337 vs. €511, p < 0.01) and less outpatient testing after the index ED visit (10 4% vs. 26 10%, p < 0.01). There was no difference in incidence of undetected ACS. Conclusions CCTA, applied early in the work-up of suspected ACS, is safe and associated with less outpatient testing and lower costs. However, in the era of hs-troponins, CCTA does not identify more patients with significant CAD requiring coronary revascularization, shorten hospital stay, or allow for more direct discharge from the ED. (Better Evaluation of Acute Chest Pain with Computed Tomography Angiography BEACON; NCT01413282 )
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