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Objectives: This study sought to examine the feasibility, safety, clinical outcomes, and costs associated with computed tomography-derived fractional flow reserve (FFR CT ) in acute chest pain (ACP) patients in a coronary computed tomography angiography (CTA)-based triage program., Background: FFR CT is useful in determining lesion-specific ischemia in patients with stable ischemic heart disease, but its utility in ACP has not been studied., Methods: ACP patients with no known coronary artery disease undergoing coronary CTA and coronary CTA with FFR CT were studied. FFR CT  ≤0.80 was considered positive for hemodynamically significant stenosis., Results: Among 555 patients, 297 underwent coronary CTA and FFR CT (196 negative, 101 positive), whereas 258 had coronary CTA only. The rejection rate for FFR CT was 1.6%. At 90 days, there was no difference in major adverse cardiac events (including death, nonfatal myocardial infarction, and unexpected revascularization after the index visit) between the coronary CTA and FFR CT groups (4.3% vs. 2.7%; p = 0.310). Diagnostic failure, defined as discordance between the coronary CTA or FFR CT results with invasive findings, did not differ between the groups (1.9% vs. 1.68%; p = NS). No deaths or myocardial infarction occurred with negative FFR CT when revascularization was deferred. Negative FFR CT was associated with higher nonobstructive disease on invasive coronary angiography (56.5%) than positive FFR CT (8.0%) and coronary CTA (22.9%) (p < 0.001). There was no difference in overall costs between the coronary CTA and FFR CT groups ($8,582 vs. $8,048; p = 0.550)., Conclusions: In ACP, FFR CT is feasible, with no difference in major adverse cardiac events and costs compared with coronary CTA alone. Deferral of revascularization is safe with negative FFR CT , which is associated with higher nonobstructive disease on invasive angiography., (Copyright © 2020 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

This expert consensus statement from the Society of Cardiovascular Computed Tomography (SCCT) provides an evidence synthesis on the use of computed tomography (CT) imaging for diagnosis and risk stratification of coronary artery disease in women. From large patient and population cohorts of asymptomatic women, detection of any coronary artery calcium that identifies females with a 10-year atherosclerotic cardiovascular disease risk of >7.5% may more effectively triage women who may benefit from pharmacologic therapy. In addition to accurate detection of obstructive coronary artery disease (CAD), CT angiography (CTA) identifies nonobstructive atherosclerotic plaque extent and composition which is otherwise not detected by alternative stress testing modalities. Moreover, CTA has superior risk stratification when compared to stress testing in symptomatic women with stable chest pain (or equivalent) symptoms. For the evaluation of symptomatic women both in the emergency department and the outpatient setting, there is abundant evidence from large observational registries and multi-center randomized trials, that CT imaging is an effective procedure. Although radiation doses are far less for CT when compared to nuclear imaging, radiation dose reduction strategies should be applied in all women undergoing CT imaging. Effective and appropriate use of CT imaging can provide the means for improved detection of at-risk women and thereby focus preventive management resulting in long-term risk reduction and improved clinical outcomes., (Copyright © 2018 Society of Cardiovascular Computed Tomography. All rights reserved.)

Background: To date, the clinical utility of coronary computed tomography angiography (CTA)-derived fractional flow reserve (FFRCT) has been limited to trials and single center experiences. We herein report the incidence of abnormal FFRCT (≤0.80) and the relationship of lesion-specific ischemia to subject demographics, symptoms, and degree of stenosis in the multicenter, prospective ADVANCE registry., Methods: One thousand patients with suspected angina having documented coronary artery disease on coronary CTA and clinically referred for FFR CT were prospectively enrolled in the registry. Patient demographics, symptom status, coronary CTA and FFR CT findings were recorded. Univariate and multivariate analyses were performed to investigate the predictors related to abnormal FFR CT ., Results: FFR CT data were analyzed in 952 patients (95.2%). Overall, 51.1% patients had a positive FFR CT value (≤0.80). Patients with ≥3 risk factors had a significantly higher rate of abnormal FFR CT than those with <3 risk factors (60.2% vs. 43.9%, p = 0.0001). On multivariate analysis, baseline diabetes (odds ratio [OR] 1.52, 95% confidence interval [CI] 1.04-2.21, p = 0.030) and hypertension (OR 1.56, 95%CI 1.14-2.14, p = 0.005) were both predictive of abnormal FFR CT . In addition, >70% stenosis was significantly associated with low FFR CT (OR 31.16, 95%CI 12.25-79.22, p < 0.0001) vs. <30% stenosis. Notably, stenosis 30-49% vs. <30% had an increased likelihood of ischemia (OR 3.74, 95%CI 1.52-9.17, p < 0.0001)., Conclusions: In this real-world registry, CT angiographic stenosis severity in addition to baseline cardiovascular risk factors conferred an increased likelihood of an abnormal FFR CT . Importantly, however, mild CT angiographic stenoses were noted to have an increased hazard for ischemia and the converse holding true for more severe stenoses as well., (Copyright © 2018 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)

Background: Coronary CT angiography (CTA) is a reliable tool for the detection of coronary artery disease (CAD) that conveys significant prognostic information. It does not provide data on the hemodynamic significance of a given lesion, particularly in intermediate-grade stenosis. Fractional flow reserve by CT (FFR CT ) can accurately predict the hemodynamic significance of coronary lesions. The primary objective of this registry is to determine whether the integration of FFR CT as an adjunct to coronary CTA will lead to a significant change in the management of CAD in patients with stable angina., Methods: The ADVANCE Registry is a multi-center, prospective registry designed to evaluate utility, clinical outcomes and resource utilization following FFR CT -guided treatment in clinically stable, symptomatic patients diagnosed with CAD by coronary CTA. Approximately 5000 patients will be enrolled from up to 50 sites in Europe, USA, Canada and Asia. Requirement for enrollment is the presence of atherosclerosis on coronary CTA. For each enrolled patient, a clinical management review committee will use data from coronary CTA and FFR CT to determine the management plan using the following criteria: (a) optimal medical therapy, (b) percutaneous coronary intervention, (c) coronary artery bypass graft surgery, or (d) more information required. The primary endpoint of the registry is the reclassification rate between the management plan based on coronary CTA alone versus CTA plus FFR CT . The secondary endpoints of the registry include the evaluation of the rate of invasive coronary angiography (ICA), revascularization, major adverse coronary events, resource utilization, cumulative radiation dose exposure and the rate of ICA without obstructive CAD at 3-year follow-up., Conclusions: The ADVANCE registry is designed to assess the real-world impact of FFR CT on the clinical management of stable CAD when used along with coronary CTA., (Copyright © 2016 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)

Due to the discrepancy between higher symptom burden and lower disease prevalence, the diagnosis of coronary artery disease (CAD) in women is challenging. Cardiac CT can be particularly useful in CAD diagnosis and risk stratification in women. In this review, we explore cardiac CT in women with and without symptoms and for adjudication of functional tests. Novel CT technologies such as fractional flow reserve and stress perfusion imaging and their potential for usefulness in women are also examined.

Aims: This study was designed to determine whether coronary CT angiography (CTA) can detect features of plaque disruption in clinically stable patients and to compare lesion prevalence and features between stable patients and those with acute coronary syndrome (ACS)., Methods: We retrospectively identified patients undergoing CTA, followed by invasive coronary angiography (ICA) within 60 days. Quantitative 3-vessel CTA lesion analysis was performed on all plaques ≥25% stenosis to assess total plaque volume, low attenuation plaque (LAP, <50 HU) volume, and remodelling index. Plaques were qualitatively assessed for CTA features of disruption, including ulceration and intra-plaque dye penetration (IDP). ICA was employed as a reference standard for disruption. A total of 145 (94 ACS and 51 stable) patients were identified. By CTA, plaque disruption was evident in 77.7% of ACS cases. Although more common among those with ACS, CTA also detected plaque disruption in 37.3% of clinically stable patients (P < 0.0001)., Conclusions: Clinically stable patients commonly manifest plaques with features of disruption as determined by CTA. Though the prevalence of plaque disruption is less than patients with ACS, these findings support the concept that some clinically stable patients may harbour 'silent' disrupted plaques. These findings may have implications for detection of 'at risk' plaques and patients., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.)

Aims: Coronary computed tomographic angiography (CCTA) has become an important tool for non-invasive diagnosis of coronary artery disease (CAD). Coronary dominance can be assessed by CCTA; however, the predictive value of coronary dominance is controversially discussed. The aim of this study was to evaluate the prevalence and prognosis of coronary dominance in a large prospective, international multicentre cohort of patients undergoing CCTA., Methods and Results: The study population consisted of 6382 patients with or without CAD (47% females, 53% males, mean age 56.9 ± 12.3 years) who underwent CCTA and were followed over a period of 60 months. Right or left coronary dominance was determined. Right dominance was present in 91% (n = 5817) and left in 9% (n = 565) of the study population. At the end of follow-up, outcome in patients with obstructive CAD (>50% luminal stenosis) and right dominance was similar compared with patients with left dominance [hazard ratio (HR) 0.46, 95% CI 0.16-1.32, P = 0.15]. Furthermore, no differences were observed for the type of coronary dominance in patients with non-obstructive CAD (HR 0.95, 95% CI 0.41-2.21, P = 0.8962) or normal coronary arteries (HR 1.04, 95% CI 0.68-1.59, P = 0.9). Subgroup analysis in patients with left main disease revealed an elevated hazard of the combined endpoint for left dominance (HR 6.45, 95% CI 1.66-25.0, P = 0.007), but not for right dominance., Conclusion: In our study population, survival after 5 years of follow-up did not differ significantly between patients with left or right coronary dominance. Thus, assessment of coronary vessel dominance by CCTA may not enhance risk stratification in patients with normal coronary arteries or obstructive CAD, but may add prognostic information for specific subpopulations., (© The Author 2015. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Objectives: This study sought to evaluate the diagnostic yield of triple rule out (TRO) versus coronary computed tomography angiography (CTA) scanning in patients with acute chest pain enrolled in a large statewide registry., Background: Although TRO scans provide simultaneous evaluation of coronary artery disease (CAD), pulmonary embolism (PE), and aortic disease (AD), their use is not well defined., Methods: Patients undergoing TRO or coronary CTA at 53 Michigan institutions for acute chest pain (in the emergency department or inpatient setting) in the ACIC (Advanced Cardiovascular Imaging Consortium) were included. Demographic characteristics, scan findings, and image quality parameters were compared between coronary CTA and TRO scans. The primary outcome was diagnostic yield, defined as obstructive CAD (>50% stenosis), PE, or AD; secondary outcomes were radiation dose, contrast volume, and image quality., Results: From July 2007 to September 2013, 12,834 patients underwent computed tomography scanning (TRO, n = 1,555; coronary CTA, n = 11,279). The TRO group had more women (57.1% vs. 47.8%, p < 0.001). Diagnostic yield was similar (TRO, 17.4% vs. coronary CTA, 18.3%; p = 0.37), driven by CAD (15.5% vs. 17.2%, p = 0.093); PE and AD were 1.1% and 0.4% (p = 0.004) and 1.7% and 1.1% (p = 0.046). TRO had higher median radiation (9.1 mSv vs. 6.2 mSv; p < 0.0001) and mean contrast (113 ± 6 ml vs. 89 ± 17 ml; p < 0.0001) doses. Nondiagnostic images were frequent in TRO (9.4% vs. 6.5%; p < 0.0001). In emergency department patients, PE and AD were more often detected on TRO. Among inpatients, there were no differences in overall yield or in that of PE, AD, or CAD., Conclusions: TRO was associated with slightly higher yield of PE and AD, specifically in the emergency department. This benefit comes with higher nondiagnostic image quality, radiation, and contrast doses. Although TRO may be of value in selected patients, its indiscriminate use is not warranted. The appropriate use of TRO needs to be further defined. (Advanced Cardiovascular Imaging Consortium [ACIC]; NCT00640068)., (Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: β-Blockers are often used for heart rate control during coronary CT angiography (CTA). Increased frequency and severity of allergic reactions to radiocontrast media (RCM) have been reported with concomitant use of β-blockers., Objectives: The objectives of this study were to determine whether there is a higher incidence of allergic reactions to low-osmolar nonionic RCM in patients undergoing coronary CTA with concomitant β-blockers and to define the overall incidence and severity of allergic reactions in patients undergoing coronary CTA with and without a history of allergy to RCM., Methods: Patients undergoing coronary CTA at 47 institutions participating in the Advanced Cardiovascular Imaging Consortium registry were analyzed. The incidence and severity of allergic reactions were compared between those patients who did and those who did not receive β-blockers, as well as in subgroups of patients with and without a history of prior allergy to RCM., Results: The incidence of allergic reaction in patients who received β-blockers was 45 of 23,867 (0.19%) compared with those who did not receive β-blockers, which was 9 of 5232 (0.17%; P = .84; odds ratio = 1.1). Of the patients with history of allergy to RCM, 4 of 706 patients (0.6%) on β-blockers experienced allergic reactions compared to 1 of 77 patients (1.3%) without β-blockers (P = .40; odds ratio = 0.43)., Conclusions: β-Blocker pretreatment had no effect on the frequency or severity of allergic reaction in patients undergoing coronary CTA, even in patients with a past history of allergy to RCM., (Copyright © 2015 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)

Purpose: To determine the clinical outcomes of women and men with nonobstructive coronary artery disease ( CAD coronary artery disease ) with coronary computed tomographic (CT) angiography data in patients who were similar in terms of CAD coronary artery disease risk factors, angina typicality, and CAD coronary artery disease extent and distribution., Materials and Methods: Institutional review board approval was obtained for all participating sites, with either informed consent or waiver of informed consent. In a prospective international multicenter cohort study of 27 125 patients undergoing coronary CT angiography at 12 centers, 18 158 patients with no CAD coronary artery disease or nonobstructive (<50% stenosis) CAD coronary artery disease were examined. Men and women were propensity matched for age, CAD coronary artery disease risk factors, angina typicality, and CAD coronary artery disease extent and distribution, which resulted in a final cohort of 11 462 subjects. Nonobstructive CAD coronary artery disease presence and extent were related to incident major adverse cardiovascular events ( MACE major adverse cardiovascular events ), which were inclusive of death and myocardial infarction and were estimated by using multivariable Cox proportional hazards models., Results: At a mean follow-up ± standard deviation of 2.3 years ± 1.1, MACE major adverse cardiovascular events occurred in 164 patients (0.6% annual event rate). After matching, women and men experienced identical annualized rates of myocardial infarction (0.2% vs 0.2%, P = .72), death (0.5% vs 0.5%, P = .98), and MACE major adverse cardiovascular events (0.6% vs 0.6%, P = .94). In multivariable analysis, nonobstructive CAD coronary artery disease was associated with similarly increased MACE major adverse cardiovascular events for both women (hazard ratio: 1.96 [95% confidence interval { CI confidence interval }: 1.17, 3.28], P = .01) and men (hazard ratio: 1.77 [95% CI confidence interval : 1.07, 2.93], P = .03)., Conclusion: When matched for age, CAD coronary artery disease risk factors, angina typicality, and nonobstructive CAD coronary artery disease extent, women and men experience comparable rates of incident mortality and myocardial infarction.

Purpose: To assess whether gradations of left ventricular (LV) ejection fraction (LVEF) and volumes measured with coronary computed tomography (CT) would augment risk stratification and discrimination for incident mortality., Materials and Methods: This study was approved by the institutional review board, and informed consent was obtained when required. Subjects without known coronary artery disease (CAD) who underwent cardiac CT angiography with quantitative LV measurements were categorized according to LVEF (≥ 55%, 45%-54.9%, 35%-44.9%, or <35%). LV end-systolic volume (LVESV) and LV end-diastolic volume (LVEDV) were classified as normal (≥ 90 mL) or abnormal (≥ 200 mL). CAD extent and severity was categorized as none, nonobstructive, obstructive (≥ 50%), one-vessel, two-vessel, and three-vessel or left main disease. LVEF and volumes were assessed for risk prediction and discrimination of future mortality by using Cox hazards model and receiver operating characteristic curve analysis, respectively., Results: During a follow-up of 2.0 years ± 0.9, 7758 patients (mean age, 58.5 years ± 13.0; 4220 male patients [54.4%]) were studied. At multivariable analysis, worsening LVEF was independently associated with mortality for moderately (hazard ratio = 3.14, P < .001) and severely (hazard ratio = 5.19, P < .001) abnormal ejection fraction. LVEF demonstrated improved discrimination for mortality (Az = 0.816) when compared with CAD risk factors alone (Az = 0.781) or CAD risk factors plus extent and severity. At multivariable analysis of a subgroup of 3706 individuals, abnormal LVEDV (hazard ratio = 4.02) and LVESV (hazard ratio = 6.46) helped predict mortality (P < .001). Similarly, LVESV and LVEDV demonstrated improved discrimination when compared with CAD risk factors or CAD extent and severity (P < .05)., Conclusion: LV dysfunction and volumes measured with cardiac CT angiography augment risk prediction and discrimination for future mortality., (© RSNA, 2014.)

Background: Coronary artery disease (CAD) diagnosis by coronary computed tomographic angiography (CCTA) is useful for identification of symptomatic diabetic individuals at heightened risk for death. Whether CCTA-detected CAD enables improved risk assessment of asymptomatic diabetic individuals beyond clinical risk factors and coronary artery calcium scoring (CACS) remains unexplored., Methods: From a prospective 12-center international registry of 27,125 individuals undergoing CCTA, we identified 400 asymptomatic diabetic individuals without known CAD. Coronary stenosis by CCTA was graded as 0%, 1-49%, 50-69%, and ≥70%. CAD was judged on a per-patient, per-vessel and per-segment basis as maximal stenosis severity, number of vessels with ≥50% stenosis, and coronary segments weighted for stenosis severity (segment stenosis score), respectively. We assessed major adverse cardiovascular events (MACE) - inclusive of mortality, nonfatal myocardial infarction (MI), and late target vessel revascularization ≥90 days (REV) - and evaluated the incremental utility of CCTA for risk prediction, discrimination and reclassification., Results: Mean age was 60.4 ± 9.9 years; 65.0% were male. At a mean follow-up 2.4 ± 1.1 years, 33 MACE occurred (13 deaths, 8 MI, 12 REV) [8.25%; annualized rate 3.4%]. By univariate analysis, per-patient maximal stenosis [hazards ratio (HR) 2.24 per stenosis grade, 95% confidence interval (CI) 1.61-3.10, p < 0.001], increasing numbers of obstructive vessels (HR 2.30 per vessel, 95% CI 1.75-3.03, p < 0.001) and segment stenosis score (HR 1.14 per segment, 95% CI 1.09-1.19, p < 0.001) were associated with increased MACE. After adjustment for CAD risk factors and CACS, maximal stenosis (HR 1.80 per grade, 95% CI 1.18-2.75, p = 0.006), number of obstructive vessels (HR 1.85 per vessel, 95% CI 1.29-2.65, p < 0.001) and segment stenosis score (HR 1.11 per segment, 95% CI 1.05-1.18, p < 0.001) were associated with increased risk of MACE. Beyond age, gender and CACS (C-index 0.64), CCTA improved discrimination by maximal stenosis, number of obstructive vessels and segment stenosis score (C-index 0.77, 0.77 and 0.78, respectively). Similarly, CCTA findings improved risk reclassification by per-patient maximal stenosis [integrated discrimination improvement (IDI) index 0.03, p = 0.03] and number of obstructive vessels (IDI index 0.06, p = 0.002), and by trend for segment stenosis score (IDI 0.03, p = 0.06)., Conclusion: For asymptomatic diabetic individuals, CCTA measures of CAD severity confer incremental risk prediction, discrimination and reclassification on a per-patient, per-vessel and per-segment basis., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Background: A best-practice intervention previously demonstrated significant dose reduction over a period of one year. We sought to evaluate whether this reduction would be incremental and sustained by promoting new scanner technology in the context of an ongoing quality improvement program during a 3-year period in a statewide registry of coronary computed tomography angiography., Methods and Results: In this prospective, controlled, nonrandomized study involving 11 901 patients at 15 Michigan centers participating in the Advanced Cardiovascular Imaging Consortium, radiation doses and image quality were compared between the following periods: control (May to June 2008) versus follow-up I (July 2008 to June 2009) and follow-up I versus follow-up II (July 2009 to April 2011). Intervention during these study periods included continuous education, feedback, and mandatory participation in this initiative. The median radiation dose remained unchanged from control to follow-up I: dose-length product of 697 (interquartile range, 407-1163) to 675 (interquartile range, 418-1146) mGy·cm (P=0.93). With the introduction of newer technology in follow-up I period, there was incremental 31% decrease during follow-up II to median dose-length product of 468 (interquartile range, 292-811) mGy·cm (P<0.0001). No significant change was noted in the percentage of diagnostic quality scans from follow-up I (92%) to follow-up II (92.7%)., Conclusions: Although ongoing application of a best-practice algorithm was associated with sustaining previously achieved targets, the use of newer scanner technology resulted in incremental radiation dose reduction in a statewide coronary computed tomography angiography registry without image quality degradation. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00640068.

Patients with chronic kidney disease have a worse cardiovascular prognosis than those without. The aim of this study was to determine the incremental prognostic value of coronary computed tomographic angiography in predicting mortality across the entire spectrum of renal function in patients with known or suspected coronary artery disease (CAD). A large international multicenter registry was queried, and patients with left ventricular ejection fraction (LVEF) and creatinine data were screened. National Cholesterol Education Program Adult Treatment Panel III risk was calculated. Coronary computed tomographic angiographic results were evaluated for CAD severity (normal, nonobstructive, or obstructive) and an LVEF <50%. Patients were followed for the end point of all-cause mortality. Among 5,655 patients meeting the study criteria, follow-up was available for 5,572 (98.9%; median follow-up duration 18.6 months). All-cause mortality (66 deaths) significantly increased with every 10-unit decrease in renal function (hazard ratio [HR] 1.23, 95% confidence interval [CI] 1.07 to 1.41). All-cause mortality occurred in 0.33% of patients without coronary atherosclerosis, 1.82% of patients with nonobstructive CAD, and 2.43% of patients with obstructive CAD. Multivariate Cox proportional-hazards models revealed that impaired renal function (HR 2.29, 95% CI 1.65 to 3.18), CAD severity (HR 1.81, 95% CI 1.31 to 2.51), and an abnormal LVEF (HR 4.16, 95% CI 2.45 to 7.08) were independent predictors of all-cause mortality. In conclusion, coronary computed tomographic angiographic measures of CAD severity and the LVEF provide effective risk stratification across a wide spectrum of renal function. Furthermore, renal dysfunction, CAD severity, and the LVEF have additive value for predicting all-cause death in patients with suspected obstructive CAD., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Objectives: This study sought to examine patterns of follow-up invasive coronary angiography (ICA) and revascularization (REV) after coronary computed tomography angiography (CCTA)., Background: CCTA is a noninvasive test that permits direct visualization of the extent and severity of coronary artery disease (CAD). Post-CCTA patterns of follow-up ICA and REV are incompletely defined., Methods: We examined 15,207 intermediate likelihood patients from 8 sites in 6 countries; these patients were without known CAD, underwent CCTA, and were followed up for 2.3 ± 1.2 years for all-cause mortality. Coronary artery stenosis was judged as obstructive when ≥50% stenosis was present. A multivariable logistic regression was used to estimate ICA use. A Cox proportional hazards model was used to estimate all-cause mortality., Results: During follow-up, ICA rates for patients with no CAD to mild CAD according to CCTA were low (2.5% and 8.3%), with similarly low rates of REV (0.3% and 2.5%). Most ICA procedures (79%) occurred ≤3 months of CCTA. Obstructive CAD was associated with higher rates of ICA and REV for 1-vessel (44.3% and 28.0%), 2-vessel (53.3% and 43.6%), and 3-vessel (69.4% and 66.8%) CAD, respectively. For patients with <50% stenosis, early ICA rates were elevated; over the entirety of follow-up, predictors of ICA were mild left main, mild proximal CAD, respectively, or higher coronary calcium scores. In patients with <50% stenosis, the relative hazard for death was 2.2 (p = 0.011) for ICA versus no ICA. Conversely, for patients with CAD, the relative hazard for death was 0.61 for ICA versus no ICA (p = 0.047)., Conclusions: These findings support the concept that CCTA may be used effectively as a gatekeeper to ICA., (Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objectives: The purpose of the study was to determine the effectiveness of a collaborative educational, continuous quality improvement (CQI) initiative to increase appropriate use of coronary computed tomography angiography (CCTA)., Background: Potential overuse of CCTA has prompted multisociety appropriate use criteria (AUC) publications., Methods: This prospective, observational study was conducted with pre-intervention (July 2007 to June 2008), intervention (July 2008 to June 2010), and follow-up (July 2010 to December 2010) periods during which patients were enrolled in the Advanced Cardiovascular Imaging Consortium (ACIC) at 47 Michigan hospitals. Continuous education was provided to referring physicians. The possibility of losing third-party payer coverage in the absence of a measurable change in AUC was emphasized. AUC was compared between the 3 periods., Results: The study group included 25,387 patients. Compared with the pre-intervention period, there was a 23.4% increase in appropriate (61.3% to 80%, p < 0.0001), 60.3% decrease in inappropriate (14.6% to 5.8%, p < 0.0001), 40.8% decrease in uncertain (10.3% to 6.1%, p < 0.0001), and 41.7% decrease in unclassifiable (13.9% to 8.1%, p < 0.0001) scans during follow-up. Between pre-intervention and follow-up, change in CCTA referrals by provider specialty were cardiology (appropriate: 60.4% to 79.5%; inappropriate: 13% to 5.2%; p < 0.0001), internal medicine/family practice (appropriate: 51.1% to 70.4%; inappropriate: 20.2% to 12.5%; p < 0.0001), emergency medicine (appropriate: 83.6% to 91.6%; inappropriate: 9.1% to 0.6%; p < 0.0001), and other (appropriate: 61.1% to 83.2%; inappropriate: 18.6% to 5.9%; p < 0.0001)., Conclusions: Application of a systematic CQI and emphasis on possible loss of coverage were associated with a significant improvement in the proportion of CCTA examinations meeting AUC across referring physician specialties., (Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: The predictive value of coronary computed tomographic angiography (cCTA) in subjects without chest pain syndrome (CPS) has not been established. We investigated the prognostic value of coronary artery disease detection by cCTA and determined the incremental risk stratification benefit of cCTA findings compared with clinical risk factor scoring and coronary artery calcium scoring (CACS) for individuals without CPS., Methods and Results: An open-label, 12-center, 6-country observational registry of 27 125 consecutive patients undergoing cCTA and CACS was queried, and 7590 individuals without CPS or history of coronary artery disease met the inclusion criteria. All-cause mortality and the composite of all-cause mortality and nonfatal myocardial infarction were measured. During a median follow-up of 24 months (interquartile range, 18-35 months), all-cause mortality occurred in 136 individuals. After risk adjustment, compared with individuals without evidence of coronary artery disease by cCTA, individuals with obstructive 2- and 3-vessel disease or left main coronary artery disease experienced higher rates of death and composite outcome (P<0.05 for both). Both CACS and cCTA significantly improved the performance of standard risk factor prediction models for all-cause mortality and the composite outcome (likelihood ratio P<0.05 for all), but the incremental discriminatory value associated with their inclusion was more pronounced for the composite outcome and for CACS (C statistic for model with risk factors only was 0.71; for risk factors plus CACS, 0.75; for risk factors plus CACS plus cCTA, 0.77). The net reclassification improvement resulting from the addition of cCTA to a model based on standard risk factors and CACS was negligible., Conclusions: Although the prognosis for individuals without CPS is stratified by cCTA, the additional risk-predictive advantage by cCTA is not clinically meaningful compared with a risk model based on CACS. Therefore, at present, the application of cCTA for risk assessment of individuals without CPS should not be justified.

Background: Coronary computed tomography angiography (CCTA) is an emerging noninvasive anatomical method for evaluation of patients with suspected coronary artery disease (CAD). Multicenter clinical registries are key to efforts to establish the role of CCTA in CAD diagnosis and management. The Advanced Cardiovascular Imaging Consortium (ACIC) is a statewide, multicenter collaborative quality initiative with the intent to establish quality and appropriate use of CCTA in Michigan., Methods: The ACIC is sponsored by the Blue Cross Blue Shield of Michigan/Blue Care Network, and its 47 sites include imaging centers that offer CCTA and meet established structure and process standards for participation. Patients enrolled include those with suspected ischemia with or without known CAD, and individuals across the entire spectrum of CAD risk. Patient demographics, history, CCTA scan-related data and findings, and 90-day follow-up data are entered prospectively into a centralized database with strict validation tools and processes. Collaborative quality initiatives include radiation dose reduction and appropriate CCTA use by education and feedback to participating sites and referring physicians., Conclusions: Across a wide range of institutions, the ACIC permits evaluation of "real-world" utilization and effectiveness of CCTA and examines an alternative, nontraditional approach to utilization management wherein physicians and payers collaborate to address the growing problem of cardiac imaging overutilization., (Copyright © 2012 Mosby, Inc. All rights reserved.)

Objectives: This study was conducted to evaluate the correlation between stress test results and coronary computed tomography angiography (CCTA) findings and comparative diagnostic performance of the 2 modalities in patients undergoing invasive coronary angiography (ICA)., Background: Recent data suggest that only a third of patients undergoing ICA have obstructive coronary artery disease (CAD); accurate pre-ICA risk stratification is needed., Methods: At 47 centers participating in the ACIC (Advanced Cardiovascular Imaging Consortium) in Michigan, patients without known CAD who were undergoing CCTA within 3 months of a stress test were studied. Demographics, risk factors, symptoms, and stress test results were correlated with obstructive CAD (>50% stenosis) on CCTA and ICA., Results: Among 6,198 patients (age 56 ± 12 years, 48% men), >50% stenosis was seen in 1,158 (18.7%) on CCTA. Independent predictors included male sex (odds ratio [OR]: 2.37, 95% confidence interval [CI]: 1.83 to 3.06), current smoking (OR: 2.23, 95% CI: 1.57 to 3.17), older age (OR per 10-year increment: 2.14, 95% CI: 1.89 to 2.41), hypertension (OR: 1.8, 95% CI: 1.37 to 2.34), and typical angina (OR: 1.48, 95% CI: 1.03 to 2.12). Stress test results were not predictive. Among patients undergoing ICA (n = 621), there was a strong correlation of ICA with CCTA findings (OR: 9.09, 95% CI: 5.57 to 14.8, p < 0.001), but not stress results (OR: 0.79, 95% CI: 0.56 to 1.11, p = 0.17)., Conclusions: Stress test findings did not predict obstructive CAD on CCTA, observed in <20% of patients in this large study group. The strong association of CCTA with ICA suggests that it may serve as an effective "gatekeeper" to invasive testing in patients needing adjudication of stress test results. (Advanced Cardiovascular Imaging Consortium: A Collaborative Quality Improvement Project [ACIC]; NCT00640068)., (Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objectives: The purpose of this study was to compare the efficiency, cost, and safety of a diagnostic strategy employing early coronary computed tomographic angiography (CCTA) to a strategy employing rest-stress myocardial perfusion imaging (MPI) in the evaluation of acute low-risk chest pain., Background: In the United States, >8 million patients require emergency department evaluation for acute chest pain annually at an estimated diagnostic cost of >$10 billion., Methods: This multicenter, randomized clinical trial in 16 emergency departments ran between June 2007 and November 2008. Patients were randomly allocated to CCTA (n = 361) or MPI (n = 338) as the index noninvasive test. The primary outcome was time to diagnosis; the secondary outcomes were emergency department costs of care and safety, defined as freedom from major adverse cardiac events in patients with normal index tests, including 6-month follow-up., Results: The CCTA resulted in a 54% reduction in time to diagnosis compared with MPI (median 2.9 h [25th to 75th percentile: 2.1 to 4.0 h] vs. 6.3 h [25th to 75th percentile: 4.2 to 19.0 h], p < 0.0001). Costs of care were 38% lower compared with standard (median $2,137 [25th to 75th percentile: $1,660 to $3,077] vs. $3,458 [25th to 75th percentile: $2,900 to $4,297], p < 0.0001). The diagnostic strategies had no difference in major adverse cardiac events after normal index testing (0.8% in the CCTA arm vs. 0.4% in the MPI arm, p = 0.29)., Conclusions: In emergency department acute, low-risk chest pain patients, the use of CCTA results in more rapid and cost-efficient safe diagnosis than rest-stress MPI. Further studies comparing CCTA to other diagnostic strategies are needed to optimize evaluation of specific patient subsets. (Coronary Computed Tomographic Angiography for Systematic Triage of Acute Chest Pain Patients to Treatment [CT-STAT]; NCT00468325)., (Copyright © 2011 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Large multicenter studies validating the prognostic value of coronary computed tomographic angiography (CCTA) and left ventricular ejection fraction (LVEF) are lacking. We sought to confirm the independent and incremental prognostic value of coronary artery disease (CAD) severity measured using 64-slice CCTA over LVEF and clinical variables., Methods and Results: A large international multicenter registry (CONFIRM Registry) was queried, and CCTA patients with LVEF data on CCTA were screened. Patients with a history of myocardial infarction, coronary revascularization, or cardiac transplantation were excluded. The National Cholesterol Education Program-Adult Treatment Panel III risk was calculated for each patient, and CCTA was evaluated for CAD severity (normal, nonobstructive, non-high-risk, or high-risk CAD) and LVEF <50%. Patients were followed for an end point of all-cause mortality; 27 125 patients underwent CCTA at 12 participating centers, with a total of 14 064 patients meeting the analysis criteria. Follow-up was available for 13 966 (99.3%) patients (mean follow-up of 22.5 months; 95% confidence interval, 22.3 to 22.7 months). All-cause mortality (271 deaths) occurred in 0.65% of patients without coronary atherosclerosis, 1.99% of patients with nonobstructive CAD, 2.90% of patients with non-high-risk CAD, and 4.95% for patients with high-risk CAD. Multivariable analysis confirmed that LVEF <50% (hazard ratio, 2.74; 95% confidence interval, 2.12 to 3.51) and CAD severity (hazard ratio,1.58; 95% confidence interval, 1.42 to 1.76) were predictors of all-cause mortality, and CAD severity had incremental value over LVEF and clinical variables., Conclusions: Our results demonstrate that CCTA measures of CAD severity and LVEF have independent prognostic value. Incorporation of CAD severity provides incremental value for predicting all-cause death over routine clinical predictors and LVEF in patients with suspected obstructive CAD.

Background: Coronary CT angiography (CCTA) is an excellent tool for noninvasive assessment of coronary arteries in low- to intermediate-risk individuals. However, the accuracy of CCTA heavily depends on image quality. Our objective was to develop and validate a tool to predict pre-CCTA risk of obtaining an uninterpretable result in symptomatic patients., Methods and Results: Among 8585 symptomatic patients, we identified variables independently associated with the presence of at least 1 uninterpretable major coronary segment to create the uninterpretable risk score (URS). This risk score was developed using both clinical variables and patient variables acquired at the time the CCTA was performed (heart rate and coronary calcium). The URS was then prospectively validated among an additional 915 symptomatic patients. The URS was predictive of uninterpretable results in both the development and the validation cohorts. For every 4-point increase in the URS (range, 0 to 12), the rate of at least 1 uninterpretable coronary segment per 100 CCTA studies increased ≈1.5 fold. Increased heart rate and coronary artery calcium score were predictive of uninterpretable CCTA study results. Uninterpretable results were associated with 3-month outcomes in the development cohort., Conclusions: The URS can categorize patients who are likely to have at least 1 uninterpretable major coronary segment on CCTA. This may aid in appropriate patient selection for CCTA and avoiding radiation exposure in those likely to have an uninterpretable study. Clinical Trial Registration- URL: http:///www.clinicaltrials.gov. Unique identifier: NCT00640068.

Background: "Triple rule-out" CT angiography simultaneously evaluates coronary artery disease, pulmonary embolism, and aortic dissection in a single imaging examination. However, the clinical outcomes of this approach are unknown., Objective: Using standard cardiac CT angiography as a reference, this study was performed to describe the diagnostic yield and clinical outcomes of patients undergoing triple rule-out in clinical practice., Methods: We identified consecutive patients at 2 institutions undergoing triple rule-out or cardiac CT angiography for acute chest pain. The primary outcome was a composite diagnostic yield consisting of coronary artery diameter stenosis >50%, pulmonary embolism, and aortic dissection. Other reported outcomes included radiation dose, downstream resource use, and 90-day clinical outcomes., Results: Among 2068 patients (272 triple rule-out and 1796 cardiac CT angiograms), the composite diagnostic yield was 14.3% with triple rule-out and 16.3% with cardiac CT (P = 0.41) and was driven by the diagnosis of obstructive coronary artery disease (13.2% triple rule-out versus 16.1% cardiac CT, P = 0.22). The diagnostic yield for pulmonary embolism was low (1.1% triple rule-out and 0.2% cardiac CT, P = 0.052) and no aortic dissections were found in either group. Compared with cardiac CT, the triple rule-out approach was associated with higher radiation exposure (12.0 ± 5.6 mSv versus 8.2 ± 4.0 mSv, P < 0.0001), a greater incidence of subsequent emergency center cardiac evaluations (5.9% versus 2.5%, P = 0.0017), and more downstream pulmonary embolism-protocol CT angiography (3.3% versus 0.9%, P = 0.0034)., Conclusions: Among patients with acute chest pain, a triple rule-out approach resulted in higher radiation exposure compared with cardiac CT, but was not associated with improved diagnostic yield, reduced clinical events, or diminished downstream resource use., (Copyright © 2011 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)

Background: This study was designed as a "proof-of-concept" to establish whether coronary computed tomographic angiography (CTA) has the capability to identify morphological features of plaque disruption., Methods and Results: In patients with unstable angina undergoing CTA and invasive coronary angiography within 30 days, quantitative CTA analysis was performed on all plaques for percent stenosis, volume, remodeling index, and volume of low-attenuation plaque (<50 Hounsfield units). Plaques with >25% stenosis were evaluated for CTA features of disruption, including ulceration and intraplaque dye penetration. Using invasive coronary angiography complex plaque as the reference standard for disruption, the sensitivity and specificity of ulceration and intraplaque dye penetration by CTA were determined. In 60 patients, 294 plaques were identified by CTA, of which 109 (37%) had features of disruption, including ulceration in 53 (18%) lesions and intraplaque dye penetration in 80 (27%). Compared with nondisrupted lesions, plaques with ulceration or intraplaque dye penetration by CTA were more voluminous (313±356 mm(3) versus 118±93 mm(3) P<0.0001), more often positively remodeled (94.5% versus 44.3%, P<0.0001), contained more low-attenuation plaque (99±161 mm(3) versus 19±18 mm(3), P<0.0001), and were more often complex by ICA (57.8% versus 8.1%, P<0.0001). CTA features of disruption demonstrated modest to good sensitivity (53% to 81%) and good specificity (82% to 95%) for complex plaque by invasive coronary angiography., Conclusions: In this highly selected group of patients with unstable angina, CTA can delineate features of plaque disruption, including ulceration and intraplaque dye penetration, which are specific markers of invasively identified complex plaque. Further studies are needed to confirm the generalizability of the results and to explore the clinical and prognostic implications of these findings.

Background: Coronary computed tomographic angiography (CCTA) of 64-detector rows or greater represents a novel noninvasive anatomic method for evaluation of patients with suspected coronary artery disease (CAD). Early studies suggest a potential for prognostic risk assessment by CCTA findings but were limited by small patient cohorts or single centers. The CONFIRM (COronary CT Angiography EvaluatioN For Clinical Outcomes: An InteRnational Multicenter) registry is a large, prospective, multinational dynamic observational study of patients undergoing CCTA. The primary aim of CONFIRM is to determine the prognostic value of CCTA findings for the prediction of future adverse CAD events., Methods: The CONFIRM registry currently represents 27,125 consecutive patients at 12 cluster sites in 6 countries in North America, Europe, and Asia. CONFIRM sites were chosen on the basis of adequate CCTA volume, site CCTA proficiency, and local demographic characteristics and medical facilities to ensure a broad-based sample of patients. Patients comprising the present CONFIRM cohort include those with suspected but without known CAD, with known CAD, or asymptomatic persons undergoing CAD evaluation. A data dictionary comprising a wide array of demographic, clinical, and CCTA findings was developed by the CONFIRM investigators and is uniformly used for all patients. Patients are followed up after CCTA performance to identify adverse CAD events, including death, myocardial infarction, unstable angina, target vessel revascularization, and CAD-related hospitalization., Conclusions: From a number of countries worldwide, the information collected from the CONFIRM registry will add incremental and important insights into CCTA findings that confer prognostic value beyond demographic and clinical characteristics. The results of the CONFIRM registry will provide valuable information about the optimal methods for using CCTA findings., (Copyright © 2011 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)

In the United States alone, nearly 6 million patients present annually to emergency departments with complaints of chest pain suggestive of acute coronary ischemia. Most of these patients have a non-negligible risk for acute coronary syndrome(s) (ACS) and undergo extended observation and workup for an ischemic cause. Of those admitted for extended observation, less than 30% of patients have true ACS. In patients with a low to intermediate probability, cardiac CT performs well in ruling out coronary artery disease, and American College of Cardiology and American Heart Association guidelines deem this application to be "appropriate." This article reviews the application of CT for the evaluation of acute chest pain the emergency department.

Background: Management of patients with suspected coronary artery disease (CAD) and inconclusive stress imaging test findings may result in invasive coronary angiography (ICA). Coronary computed tomographic angiography (CCTA) may be useful in defining the risk of CAD and adverse outcomes in this patient population, as well as in reducing the need for ICA., Methods: We prospectively enrolled 199 sequential patients referred by cardiologists for CCTA after either inconclusive or nondiagnostic stress imaging tests. Before CCTA, physicians identified a "planned catheterization" group of patients who would undergo invasive angiography if CCTA were not available. After CCTA testing, patients were followed for >or=2 years. We established the added diagnostic value of the CCTA and its prognostic power in prediction of intermediate-term follow-up events in this patient population as compared to available historical and clinical predictors of CAD, stress ECG, and stress imaging test results using a multivariable Cox proportional hazards survival analysis., Results: Both observed data and results of the multivariable model for the prediction of obstructive CAD (>50% stenosis), or major cardiac events (death MI or revascularization), demonstrated that clinical, stress ECG, and imaging results were weakly predictive, whereas CCTA was found to be a strong independent and incremental predictor of the absence of either significant CAD or MACE in this population. None of the 93 patients with normal CCTA scans had MACE events, whereas 18 patients with evidence of CAD on the CCTA results underwent revascularization. Overall, physicians planned ICA in 125 patients (63.0%); after CCTA, ICA was performed in only 32 (16.0%) cases over 2 years. In this population with no other highly effective noninvasive clinical tools for diagnostic and prognostic estimation, the overall negative predictive value of CCTA for either CAD > 50% or MACE for 2 years was 99%., Conclusion: Observations from this prospective study demonstrate the significant added diagnostic value and prognostic potential of CCTA in patients with suspected CAD and either inconclusive or nondiagnostic stress test results in real-world settings. Normal CCTA results are associated with excellent intermediate-term prognosis in this clinical subset, and invasive angiography can be safely avoided in the majority of these patients when the results of CCTA are available.

Context: Cardiac computed tomography angiography (CCTA) can accurately diagnose coronary artery disease, but radiation dose from this procedure is of concern., Objectives: To determine whether a collaborative radiation dose-reduction program would be associated with reduced radiation dose in patients undergoing CCTA in a statewide registry over a 1-year period and to define its effect on image quality., Design, Setting, and Patients: A prospective, controlled, nonrandomized study conducted during a control period (July-August 2007), an intervention period (September 2007-April 2008), and a follow-up period (May-June 2008) at 15 hospital imaging centers participating in the Advanced Cardiovascular Imaging Consortium in Michigan, which included small community hospitals and large academic medical centers. A total of 4995 sequential patients undergoing CCTA for suspected coronary artery disease were enrolled; 4862 patients (97.3%) had complete radiation data for analysis., Intervention: A best-practice CCTA scan model was used, which included minimized scan range, heart rate reduction, electrocardiographic-gated tube current modulation, and reduced tube voltage in suitable patients., Main Outcome Measures: Primary outcomes included dose-length product and effective radiation dose from all phases of the CCTA scan. Secondary outcomes were image quality assessed by a 4-point scale (1 indicated excellent; 2, good; 3, adequate; and 4, nondiagnostic) and frequency of diagnostic-quality scans., Results: Compared with the control period, patients' estimated median radiation dose in the follow-up period was reduced by 53.3% (dose-length product decreased from 1493 mGy x cm [interquartile range {IQR}, 855-1823 mGy x cm] to 697 mGy x cm [IQR, 407-1163 mGy x cm]; P < .001) and effective dose from 21 mSv (IQR, 12-26 mSv) to 10 mSv (IQR, 6-16 mSv) (P < .001). The greatest reduction in dose occurred at low-volume sites. There were no significant changes in median image quality assessment during the control period compared with the follow-up period (median image quality of 2 [images rated as good] vs median image quality of 2; P = .13) or frequency of diagnostic-quality scans (554/620 patients [89%] vs 769/835 patients [92%]; P = .07)., Conclusion: Consistent application of currently available dose-reduction techniques was associated with a marked reduction in estimated radiation doses in a statewide CCTA registry, without impairment of image quality., Trial Registration: clinicaltrials.gov Identifier: NCT00640068.

Background: Morbidly obese persons (body mass index [BMI; in kg/m(2)] >or= 40) have an increased risk of cardiovascular morbidity and mortality but have reduced accuracy with conventional cardiac testing and coronary CT angiography (CCTA)., Objective: This study investigated a novel dual-source computed tomography (DSCT) acquisition and reconstruction method for coronary imaging in morbidly obese patients., Methods: This was a observational study in which each patient served as his or her own control. After a single DSCT acquisition using a novel method, standard quarter-scan image reconstructions at a temporal resolution of 83 milliseconds were compared with temporal resolution reconstructions at 105, 125, and 165 milliseconds. Images were evaluated for diagnostic adequacy score and for image noise, signal-to-noise ratio, and contrast-to-noise ratio. In each patient, the image reconstruction with the best visual diagnostic score was compared with the control image for quantitative measures., Results: Fifty patients (32 female; mean +/- SD age, 51 +/- 10 y; mean BMI, 44.8 +/- 5.6) were enrolled. Scans were of diagnostic quality in 47 (94%) patients using the "best reconstruction" compared with 38 (76%) patients using quarter-scan reconstruction. Significant improvements were observed in noise (42 +/- 16 HU versus 56 +/- 19 HU; P < 0.0001), contrast-to-noise ratio (8.4 +/- 3.3 HU versus 7.0 +/- 2.2 HU; P = 0.0038), and signal-to-noise ratio (7.6 +/- 2.9 HU versus 6.5 +/- 3.5 HU; P = 0.030)., Conclusions: CCTA with DSCT using a modified scan protocol and adjustable temporal reconstructions provides diagnostic image quality in >90% of morbidly obese patients.

Cardiac computed tomographic angiography (CCTA) is revolutionizing our approach to the identification and management of coronary artery atherosclerosis. CCTA has the unique ability to assess extracoronary cardiac findings within the standard field of view, including the anatomy of cardiac structures-the atria, ventricles, valves, pericardium, great vessels, and venous anatomy-and any related abnormalities. Appropriate clinical applications include evaluation of intermediate-risk patients with acute chest pain and those with suspected coronary anomalies, uninterpretable or equivocal stress test results, or suspected cardiac morphologic abnormalities. Optimization of this diagnostic examination requires close attention to details such as minimizing motion and attaining sufficient contrast opacification. Iso-osmolar contrast can help achieve maximum patient comfort with the smallest elevation of heart rate and variability, as well as minimize the risk of acute kidney injury. Newer scanning equipment and protocols have improved image quality in difficult cases, including obese patients and those with heavy coronary calcification or metal artifacts. Current imaging protocols have reduced exposure to ionizing radiation and continue to improve safety.