Angiographic severity of coronary artery stenosis has historically been the primary guide to revascularization or medical management of coronary artery disease. However, physiologic severity defined ...by coronary pressure and/or flow has resurged into clinical prominence as a potential, fundamental change from anatomically to physiologically guided management. This review addresses clinical coronary physiology—pressure and flow—as clinical tools for treating patients. We clarify the basic concepts that hold true for whatever technology measures coronary physiology directly and reliably, here focusing on positron emission tomography and its interplay with intracoronary measurements.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The aim of the study was to evaluate the impact of the latest coronary computed tomography angiography (CCTA) techniques allowing a radiation- and contrast-sparing protocol on image quality in ...unselected patients referred for exclusion of suspected coronary artery disease (CAD).
This prospective study was approved by the local ethics committee, and all patients provided written informed consent. Between March and June 2015, 89 consecutive patients (61% male; mean age 55 ± 11 years) referred for exclusion of CAD by 256-slice CCTA using prospective electrocardiogram triggering were included. Tube voltage (80-120 kVp), tube current (180-310 mA) as well contrast agent volume (25-45 mL) and flow rate (3.5-5 mL/s) were adapted to body mass index. Signal intensity was measured by placing a region of interest in the aortic root, the left main artery, and the proximal right coronary artery. Image noise was measured in the aortic root. Two independent blinded readers semi-quantitatively assessed the image quality regarding motion, noise, and contrast on a 4-point scale.
Median contrast agent volume and median effective radiation dose were 35 mL (interquartile range, 30-40 mL) and 0.5 mSv (interquartile range, 0.4-0.6 mSv), respectively. Mean attenuation in the aortic root was 412 ± 89 Hounsfield units. Diagnostic image quality was obtained in 1050 of 1067 (98.4%) coronary segments and, on an intention-to-diagnosis basis, in 85 of 89 (95.5%) patients. Below a cut-off heart rate of 67 beats/min, only 1 of 974 (0.1%) coronary segments was nondiagnostic.
A radiation- and contrast-sparing protocol for CCTA on a latest generation 256-slice computed tomography scanner yields diagnostic image quality in patients referred for CAD exclusion in daily clinical routine.
Abstract Objectives The goal of this study was to determine the long-term prognostic value of coronary computed tomography angiography (CTA) among patients with diabetes mellitus (DM) compared with ...nondiabetic subjects. Background The long-term prognostic value of coronary CTA in patients with DM is not well established. Methods Patients enrolled in the CONFIRM (Coronary CT Angiography Evaluation for Clinical Outcomes: An International Multicenter) registry with 5-year follow-up data were identified. The extent and severity of coronary artery disease (CAD) were analyzed at baseline coronary CTA and in relation to outcomes between diabetic and nondiabetic patients. CAD according to coronary CTA was defined as none (0% stenosis), nonobstructive (1% to 49% stenosis), or obstructive (≥50% stenosis). Time to death (and in a subgroup, time to major adverse cardiovascular event) was estimated by using multivariable Cox proportional hazards models. Results A total of 1,823 patients were identified as having DM with 5-year clinical follow-up and were propensity-matched to 1,823 patients without DM (mean age 61.8 ± 10.9 years; 54.4% male). Patients with DM did not exhibit a heightened risk of death compared with the propensity-matched nondiabetic subjects in the absence of CAD on coronary CTA (risk-adjusted hazard ratio HR of DM: 1.32; 95% confidence interval CI: 0.78 to 2.24; p = 0.296). Patients with DM were at increased risk of dying compared with nondiabetic subjects in the setting of nonobstructive CAD (in the propensity-matched cohort: HR, 2.10; 95% CI: 1.43 to 3.09; p < 0.001) with a mortality risk greater than nondiabetic subjects with obstructive disease (p < 0.001). In a risk-adjusted hazard analysis among patients with DM, both per-patient obstructive CAD and nonobstructive CAD conferred an increase in all-cause mortality risk compared with patients without atherosclerosis on coronary CTA (nonobstructive disease—HR: 2.07; 95% CI: 1.33 to 3.24; p = 0.001; obstructive disease—HR: 2.22; 95% CI: 1.47 to 3.36; p < 0.001). Conclusions Among patients with DM, nonobstructive and obstructive CAD according to coronary CTA were associated with higher rates of all-cause mortality and major adverse cardiovascular events at 5 years, and this risk was significantly higher than in nondiabetic subjects. Importantly, patients with DM without CAD according to coronary CTA were at a risk comparable to that of nondiabetic subjects.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Prospective electrocardiogram (ECG) triggering allows coronary computed tomography angiography (CCTA) scanning with low radiation dose but requires heart rates below 63 beats/min. We assessed the ...impact of a novel vendor-specific motion-correction algorithm on image quality and interpretability of low-dose CCTA acquired despite insufficient heart rate control.
In 40 patients undergoing CCTA for the assessment of known or suspected coronary artery disease who did not reach the target heart rate below 63 beats/min despite β-blockade before prospective low-dose scanning, the temporal acquisition window was increased (80 ms additional padding). The new algorithm detects and integrates vessel path and velocity from adjacent cardiac phases for motion correction. Two blinded observers assessed image quality on a 4-point Likert scale (1, nonevaluative; 2, reduced but evaluative; 3, good; and 4, excellent) and the fraction of interpretable segments (score 2 or more) using motion correction versus standard reconstruction.
Image reconstruction with motion correction resulted in an increased median coronary artery image quality score (excellent interobserver agreement, κ = 0.85) compared to standard reconstruction (3.4 vs. 3.0, P < .001). Consequently, motion-corrected reconstruction significantly improved the overall interpretability of coronary arteries (from 78% to 88%, P < .001). Estimated mean effective radiation dose was 2.3 ± 0.8 mSv.
A novel, vendor-specific, motion-corrected, reconstruction algorithm improves image quality and interpretability of prospectively ECG-triggered low-dose CCTA despite insufficient heart rate control.
Objectives This study was designed to determine whether multislice computed tomography (MSCT) coronary angiography has incremental prognostic value over single-photon emission computed tomography ...myocardial perfusion imaging (MPI) in patients with suspected coronary artery disease (CAD). Background Although MSCT is used for the detection of CAD in addition to MPI, its incremental prognostic value is unclear. Methods In 541 patients (59% male, age 59 ± 11 years) referred for further cardiac evaluation, both MSCT and MPI were performed. The following events were recorded: all-cause death, nonfatal infarction, and unstable angina requiring revascularization. Results In the 517 (96%) patients with an interpretable MSCT, significant CAD (MSCT ≥50% stenosis) was detected in 158 (31%) patients, and abnormal perfusion (summed stress score SSS: ≥4) was observed in 168 (33%) patients. During follow-up (median 672 days; 25th, 75th percentile: 420, 896), an event occurred in 23 (5.2%) patients. After correction for baseline characteristics in a multivariate model, MSCT emerged as an independent predictor of events with an incremental prognostic value to MPI. The annualized hard event rate (all-cause mortality and nonfatal infarction) in patients with none or mild CAD (MSCT <50% stenosis) was 1.8% versus 4.8% in patients with significant CAD (MSCT ≥50% stenosis). A normal MPI (SSS <4) and abnormal MPI (SSS ≥4) were associated with an annualized hard event rate of 1.1% and 3.8%, respectively. Both MSCT and MPI were synergistic, and combined use resulted in significantly improved prediction (log-rank test p value <0.005). Conclusions MSCT is an independent predictor of events and provides incremental prognostic value to MPI. Combined anatomical and functional assessment may allow improved risk stratification.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Abstract Anomalous coronary arteries (ACA) represent a congenital disorder with an anomalous location of the coronary ostium and/or vascular course. Although most individuals with ACA are ...asymptomatic and remain undiagnosed, some ACA variants are clinically significant leading to symptoms and even adverse cardiac events. Currently, disease prevalence, pathophysiological mechanisms, risks of sudden cardiac death, and the optimal assessment and treatment strategies among subtypes of ACA remain largely unknown. Consequently, there is a lack of guidelines regarding imaging, sport restriction, and treatment options in individuals with ACA at all ages. Cardiac imaging techniques may play a pivotal role in the assessment of individuals with ACA and may offer guidance toward an optimal treatment strategy. This state-of-the-art review highlights current challenges and future perspectives with a special focus on the role of noninvasive multimodality imaging in patients with ACA.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Abstract Background New technology combining dual-energy CT with the latest gemstone detectors for spectral imaging (GSI) can be used to synthesize monochromatic images that mimic images as if ...different monochromatic x-ray sources were used. Objective The aim of the study was to evaluate the optimal combination of monochromatic image energy and adaptive statistical iterative reconstruction (ASiR) for monochromatic reconstruction of coronary CT angiography (CTA) images with the use of GSI. Methods Twenty consecutive patients underwent coronary CTA on a GSI capable 64-slice CT scanner (Discovery CT 750 High Definition, GE Healthcare). In 7 sets of monochromatic images (60, 65, 70, 75, 80, 90, and 110 keV; each with increasing contributions of ASiR, ie, 0%, 20%, 40%, 60%, and 80%; n = 35 reconstructions per patient), signal-to-noise (aortic root) and contrast-to-noise (left main artery) ratios were assessed. Signal-to-noise ratio, contrast-to-noise ratio, and image quality (graded on a 5-point Likert scale) were assessed in all above monochromatic reconstructions and compared with the respective standard (conventional polychromatic) image. Results Compared with conventional polychromatic images, reconstructions with 60 keV and 80% ASiR showed the highest improvement in contrast-to-noise (144%; P < 0.001) and signal-to-noise ratio (173%; P < 0.001). Image quality reached a plateau at 65–75 keV with 40%–60% ASiR blending, yielding a maximal image quality score improvement of 50% compared with conventional imaging ( P < 0.001). Conclusion In coronary CTA with low radiation technique (mean radiation dose, 1.8 ± 0.7 mSv), GSI with monochromatic reconstructions (65–75 keV) and ASiR (40%–60%) offers significant noise reduction and image quality improvement.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Smoking, leukemia or lymphoma, radio- or chemotherapy, and radiation-based examinations within the past 3 days were exclusion criteria. Because concerns about increased DSBs also have been raised for ...exposure to nonionizing radiation, such as that produced by cardiac magnetic resonance or ultrasound imaging (3,4), we only included controls who did not undergo any such examination to avoid potential confounders. ...a firm conclusion regarding the reduction of carcinogenic risk by antioxidant pre-treatment may not be offered, and further evaluation in larger trials should be encouraged.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Abstract Background Coronary computed tomography angiography (CTA) is increasingly being used for evaluation of coronary artery disease (CAD). As a result of the widely reported potential of ...carcinogenic risk from x-ray based examinations, many strategies have been developed for dose reduction with CTA. Objectives The purpose of this study was to assess the diagnostic accuracy of CTA acquired with a submillisievert fraction of effective radiation dose reconstructed with a model-based iterative reconstruction (MBIR) using invasive coronary angiography (ICA) as a standard of reference. Methods In 36 patients (body mass index range 17 to 39 kg/m2 ) undergoing ICA for CAD evaluation, a CTA was acquired using very low tube voltage (80 to 100 kV) and current (150 to 210 mA) and was reconstructed with MBIR. CAD (defined as ≥50% luminal narrowing) was assessed on CTA and on ICA. Results CTA resulted in an estimated radiation dose exposure of 0.29 ± 0.12 mSv (range 0.16 to 0.53 mSv), yielding 96.9% (436 of 450) interpretable segments. On an intention-to-diagnose basis, no segment was excluded, and vessels with at least 1 nonevaluable segment and no further finding were classified as false positive. This resulted in a sensitivity, specificity, positive, and negative predictive value and accuracy of 100%, 74%, 77%, 100%, and 86% per patient and 85%, 86%, 56%, 96%, and 85% per vessel, respectively. Conclusions The use of MBIR reconstruction allows accurate noninvasive diagnosis of CAD with CTA at a submillisievert fraction of effective radiation dose comparable with a chest x-ray in 2 views.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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