Impact of atherosclerosis imaging-quantitative computed tomography on diagnostic certainty, downstream testing, coronary revascularization, and medical therapy: the CERTAIN study.

AIMS: The incremental impact of atherosclerosis imaging-quantitative computed tomography (AI-QCT) on diagnostic certainty and downstream patient management is not yet known. The aim of this study was to compare the clinical utility of the routine implementation of AI-QCT versus conventional visual coronary CT angiography (CCTA) interpretation. METHODS AND RESULTS: In this multi-centre cross-over study in 5 expert CCTA sites, 750 consecutive adult patients referred for CCTA were prospectively recruited. Blinded to the AI-QCT analysis, site physicians established patient diagnoses and plans for downstream non-invasive testing, coronary intervention, and medication management based on the conventional site assessment. Next, physicians were asked to repeat their assessments based upon AI-QCT results. The included patients had an age of 63.8 ± 12.2 years; 433 (57.7%) were male. Compared with the conventional site CCTA evaluation, AI-QCT analysis improved physician's confidence two- to five-fold at every step of the care pathway and was associated with change in diagnosis or management in the majority of patients (428; 57.1%; P < 0.001), including for measures such as Coronary Artery Disease-Reporting and Data System (CAD-RADS) (295; 39.3%; P < 0.001) and plaque burden (197; 26.3%; P < 0.001). After AI-QCT including ischaemia assessment, the need for downstream non-invasive and invasive testing was reduced by 37.1% (P < 0.001), compared with the conventional site CCTA evaluation. Incremental to the site CCTA evaluation alone, AI-QCT resulted in statin initiation/increase an aspirin initiation in an additional 28.1% (P < 0.001) and 23.0% (P < 0.001) of patients, respectively. CONCLUSION: The use of AI-QCT improves diagnostic certainty and may result in reduced downstream need for non-invasive testing and increased rates of preventive medical therapy.

The clinical evaluation of the CADence device in the acoustic detection of coronary artery disease.

The noninvasive detection of turbulent coronary flow may enable diagnosis of significant coronary artery disease (CAD) using novel sensor and analytic technology. Eligible patients (n = 1013) with chest pain and CAD risk factors undergoing nuclear stress testing were studied using the CADence (AUM Cardiovascular Inc., Northfield MN) acoustic detection (AD) system. The trial was designed to demonstrate non-inferiority of AD for diagnostic accuracy in detecting significant CAD as compared to an objective performance criteria (sensitivity 83% and specificity 80%, with 15% non-inferiority margins) for nuclear stress testing. AD analysis was blinded to clinical, core lab-adjudicated angiographic, and nuclear data. The presence of significant CAD was determined by computed tomographic (CCTA) or invasive angiography. A total of 1013 subjects without prior coronary revascularization or Q-wave myocardial infarction were enrolled. Primary analysis was performed on subjects with complete angiographic and AD data (n = 763) including 111 subjects (15%) with severe CAD based on CCTA (n = 34) and invasive angiography (n = 77). The sensitivity and specificity of AD were 78% (p = 0.012 for non-inferiority) and 35% (p < 0.001 for failure to demonstrate non-inferiority), respectively. AD results had a high 91% negative predictive value for the presence of significant CAD. AD testing failed to demonstrate non-inferior diagnostic accuracy as compared to the historical performance of a nuclear stress OPC due to low specificity. AD sensitivity was non-inferior in detecting significant CAD with a high negative predictive value supporting a potential value in excluding CAD.

Coronary computed tomography angiography predicts subsequent cardiac outcome events: results of the Visipaque CCTA registry study.

OBJECTIVES: To evaluate the diagnostic performance and predictive value of coronary computed tomography angiography (CCTA) on subsequent cardiac outcomes. BACKGROUND: CCTA has been suggested as an alternative method to invasive coronary angiography for detection of and ruling out coronary artery disease (CAD). However, the usefulness of CCTA findings in predicting patient outcome in routine clinical practice is still uncertain. MATERIALS AND METHODS: A prospective, multicenter registry study of CCTA with a Visipaque injection 320 mg I/ml was carried out in symptomatic patients suspected of having CAD as part of their medical care. CCTA findings were used to guide patient management decisions. Patient cardiac outcomes were followed at 1, 6, and 12 months after the CCTA procedure for the occurrence of major adverse cardiac event (MACE) (cardiac death, nonfatal myocardial infarction, or unstable angina requiring hospitalization). All cardiac outcome events or deaths were adjudicated independently. RESULTS: Of 874 patients (mean age=59 years; 51% men) who received Visipaque, 857 were included in the efficacy analysis. Using cardiac outcomes as the endpoint, the sensitivity of CCTA was 96.1, 95.8, and 94.7%, specificity was 84.5, 86.6, and 87.0%, and negative predictive value more than 99.0% at 1, 6, and 12 months, respectively. At 12 months, the rate of MACE was 5.7% (10/174) in patients with a positive CCTA (one or more ≥50% stenosis) and 0.1% (1/683) in patients with a negative CCTA (99.9% MACE-free survival rate). The Cox proportional hazards analysis with CCTA outcome, age, sex, reasons for CCTA, and cardiac risk factors as covariates showed a hazard ratio of 87.6 for positive versus negative CCTA (P=0.0001). CONCLUSION: CCTA is a highly accurate, noninvasive tool to detect or rule out subsequent cardiovascular events in patients with intermediate pretest probability of CAD or an uninterpretable/equivocal stress test. A positive CCTA finding contributed significantly toward the prediction of subsequent MACE whereas a negative CCTA carried excellent prognostic outcomes at 12 months.

Diagnostic accuracy of fractional flow reserve from anatomic CT angiography.

CONTEXT: Coronary computed tomographic (CT) angiography is a noninvasive anatomic test for diagnosis of coronary stenosis that does not determine whether a stenosis causes ischemia. In contrast, fractional flow reserve (FFR) is a physiologic measure of coronary stenosis expressing the amount of coronary flow still attainable despite the presence of a stenosis, but it requires an invasive procedure. Noninvasive FFR computed from CT (FFR(CT)) is a novel method for determining the physiologic significance of coronary artery disease (CAD), but its ability to identify ischemia has not been adequately examined to date. OBJECTIVE: To assess the diagnostic performance of FFR(CT) plus CT for diagnosis of hemodynamically significant coronary stenosis. DESIGN, SETTING, AND PATIENTS: Multicenter diagnostic performance study involving 252 stable patients with suspected or known CAD from 17 centers in 5 countries who underwent CT, invasive coronary angiography (ICA), FFR, and FFR(CT) between October 2010 and October 2011. Computed tomography, ICA, FFR, and FFR(CT) were interpreted in blinded fashion by independent core laboratories. Accuracy of FFR(CT) plus CT for diagnosis of ischemia was compared with an invasive FFR reference standard. Ischemia was defined by an FFR or FFR(CT) of 0.80 or less, while anatomically obstructive CAD was defined by a stenosis of 50% or larger on CT and ICA. MAIN OUTCOME MEASURES: The primary study outcome assessed whether FFR(CT) plus CT could improve the per-patient diagnostic accuracy such that the lower boundary of the 1-sided 95% confidence interval of this estimate exceeded 70%. RESULTS: Among study participants, 137 (54.4%) had an abnormal FFR determined by ICA. On a per-patient basis, diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of FFR(CT) plus CT were 73% (95% CI, 67%-78%), 90% (95% CI, 84%-95%), 54% (95% CI, 46%-83%), 67% (95% CI, 60%-74%), and 84% (95% CI, 74%-90%), respectively. Compared with obstructive CAD diagnosed by CT alone (area under the receiver operating characteristic curve [AUC], 0.68; 95% CI, 0.62-0.74), FFR(CT) was associated with improved discrimination (AUC, 0.81; 95% CI, 0.75-0.86; P < .001). CONCLUSION: Although the study did not achieve its prespecified primary outcome goal for the level of per-patient diagnostic accuracy, use of noninvasive FFR(CT) plus CT among stable patients with suspected or known CAD was associated with improved diagnostic accuracy and discrimination vs CT alone for the diagnosis of hemodynamically significant CAD when FFR determined at the time of ICA was the reference standard.

Coronary CT angiography versus myocardial perfusion imaging for near-term quality of life, cost and radiation exposure: a prospective multicenter randomized pilot trial.

BACKGROUND: Clinical outcomes and resource utilization after coronary computed tomography angiography (CTA) versus myocardial perfusion single-photon emission CT (MPS) in patients with stable angina and suspected coronary artery disease (CAD) has not been examined. OBJECTIVE: We determined the near-term clinical effect and resource utilization after cardiac CTA compared with MPS. METHODS: We randomly assigned 180 patients (age, 57.3 ± 9.8 years; 50.6% men) presenting with stable chest pain and suspected CAD at 2 sites to initial diagnostic evaluation by coronary CTA (n = 91) or MPS (n = 89). The primary outcome was near-term angina-specific health status; the secondary outcomes were incident medical and invasive treatments for CAD, CAD health care costs, and estimated radiation dose. RESULTS: No patients experienced myocardial infarction or death with 98.3% follow-up at 55 ± 34 days. Both arms experienced comparable improvements in angina-specific health status. Patients who received coronary CTA had increased incident aspirin (22% vs 8%; P = 0.04) and statin (7% vs -3.5%; P = 0.03) use, similar rates of CAD-related hospitalization, invasive coronary angiography, noninvasive cardiac imaging tests, and increased revascularization (8% vs 1%; P = 0.03). Coronary CTA had significantly lower total costs ($781.08 [interquartile range (IQR), $367.80-$4349.48] vs $1214.58 [IQR, $978.02-$1569.40]; P < 0.001) with no difference in induced costs. Coronary CTA had a significantly lower total estimated effective radiation dose (7.4 mSv [IQR, 5.0-14.0 mSv] vs 13.3 mSv [IQR, 13.1-38.0 mSv]; P < 0.0001) with no difference in induced radiation. CONCLUSION: In a pilot randomized controlled trial, patients with stable CAD undergoing coronary CTA and MPS experience comparable improvements in near-term angina-related quality of life. Compared with MPS, coronary CTA evaluation is associated with more aggressive medical therapy, increased coronary revascularization, lower total costs, and lower effective radiation dose.

Clues to cardiovascular risk: an office-based approach.

Current tools for predicting coronary heart disease risk in the asymptomatic patient fall into 2 major categories: traditional population-based models and noninvasive imaging techniques. Population-based models that estimate cardiovascular risk are powerful clinical tools but do not utilize a large volume of patient-specific data that are readily available to the clinician and may help to identify at-risk patients. The use of high-technology noninvasive imaging has not been consistently validated and clinicians or patients often lack the resources for such testing. This paper reviews several commonly encountered historical, physical, radiologic, laboratory, and electrocardiographic markers of increased cardiovascular risk that may enhance clinicians' ability to identify individual patients at increased risk for coronary heart disease.

Cost implications of initial computed tomography angiography as opposed to catheterization in patients with mildly abnormal or equivocal myocardial perfusion scans.

BACKGROUND: Patients with mildly abnormal or equivocal myocardial perfusion imaging (MPI) scans undergo diagnostic angiography or receive medical management. However, current guidelines mandate different treatment goals for patients with known coronary artery disease (CAD), and catheterization is often required. Coronary computed tomography angiography (CCTA) may be an effective alternative to catheterization for patients at intermediate risk for CAD. OBJECTIVES: The purpose of this study was to analyze the cost implications of CCTA before catheterization in patients with mildly abnormal or equivocal MPI scans. METHODS: Patients (n = 206) with mildly abnormal or equivocal MPI scans underwent 64-detector CCTA instead of catheterization at the discretion of a treating physician. Studies were evaluated by a trained reader, and results were classified as "no evident CAD," "nonobstructive CAD," or "potentially obstructive CAD." Cost data were analyzed based on actual reimbursements for CT angiography and cardiac catheterization. We modeled the costs of two clinical approaches. "Selective catheterization" involved catheterization only if CCTA showed potentially obstructive CAD. "Immediate catheterization" considered catheterization for all patients in the cohort. Sensitivity analysis was performed on multiple variables. RESULTS: Thirty-two percent of patients had potentially obstructive plaque on CTA. Selective catheterization saves $1454 per patient. Sensitivity analysis revealed cost savings to be preserved even if up to 81.5% of the patient cohort undergoes catheterization, as well as across wide ranges of procedural costs. CONCLUSION: A strategy that uses CCTA as a gatekeeper to catheterization is cost saving as opposed to initial catheterization for patients with equivocal or mildly abnormal myocardial perfusion scans.

Risk factors and outcomes in patients with coronary artery aneurysms.

Previous small series have provided conflicting data on the association between coronary artery aneurysms and traditional cardiac risk factors, as well as limited information on patient outcomes. This investigation sought to determine whether the presence of coronary artery aneurysms has an adverse affect on patient outcomes. The results show that coronary aneurysms were an independent predictor of mortality, and overall 5-year survival in patients with aneurysms was only 71%. We believe that clinicians should aggressively monitor and modify coronary risk factors in patients with coronary aneurysms.