Functional relevance of coronary artery disease by cardiac magnetic resonance and cardiac computed tomography : myocardial perfusion and fractional flow reserve

Coronary artery disease (CAD) is one of the leading causes of morbidity and mortality and it is responsible for an increasing resource burden. The identification of patients at high risk for adverse events is crucial to select those who will receive the greatest benefit from revascularization. To this aim, several non-invasive functional imaging modalities are usually used as gatekeeper to invasive coronary angiography, but the diagnostic yield of elective invasive coronary angiography remains unfortunately low. Stress myocardial perfusion imaging by cardiac magnetic resonance (stress-CMR) has emerged as an accurate technique for diagnosis and prognostic stratification of the patients with known or suspected CAD thanks to high spatial and temporal resolution, absence of ionizing radiation, and the multiparametric value including the assessment of cardiac anatomy, function, and viability. On the other side, cardiac computed tomography (CCT) has emerged as unique technique providing coronary arteries anatomy and more recently, due to the introduction of stress-CCT and noninvasive fractional flow reserve (FFR-CT), functional relevance of CAD in a single shot scan. The current review evaluates the technical aspects and clinical experience of stress-CMR and CCT in the evaluation of functional relevance of CAD discussing the strength and weakness of each approach

Induction Dosage of Propofol for Repeated Sedations in Children With Hematological Disorders

Pediatric patients with hematologic malignancies require several procedural sedations by means of propofol infusion. We retrospectively analyzed the medical records of leukemic pediatric patients who had undergone procedural sedations at an Italian tertiary referral center (San Gerardo Hospital, Monza) from January 2011 to November 2013. We retrieved the following: demographics; diagnosis; chemotherapy phase; use of corticosteroids; induction dosage of propofol, fentanyl and/or ketamine; and the type of procedure. We used a multivariate linear mixed model to evaluate the factors affecting induction propofol dose. We analyzed 1459 procedures (59% lumbar punctures, 31% bone marrow aspirations) performed on 96 children (7 [4-10]\u2009y old, 24 [16-34]\u2009kg, 37% female) admitted for acute lymphoblastic leukemia (80%), lymphoma (11%), and acute myeloid leukemia (7%). The induction propofol dose increased by 0.03\u2009mg/kg per each procedure (P<0.05), from 2.6 (2.0-3.2) to 3.5 (2.6-4.3)\u2009mg/kg at the first and the last procedure, respectively. Higher age, weight, and use of ketamine were associated to lower propofol dosage (P<0.01), while combined procedures increased propofol dosage (P<0.01). In a large cohort of leukemic pediatric patients undergoing procedural sedation, the induction dose of propofol was increased over time, regardless of weight, age, use of corticosteroids, diagnosis, and treatment phase

The New Frontier of Cardiac Computed Tomography Angiography : Fractional Flow Reserve and Stress Myocardial Perfusion

The increased number of patients with coronary artery disease (CAD) in developed countries is of great clinical relevance and involves a large burden of the healthcare system. The management of these patients is focused on relieving symptoms and improving clinical outcomes. Therefore the ideal test would provide the correct diagnosis and actionable information. To this aim, several non-invasive functional imaging modalities are usually used as gatekeeper to invasive coronary angiography (ICA), but their diagnostic yield remains low with limited accuracy when compared to obstructive CAD at the time of ICA or invasive fractional flow reserve (FFR). Invasive FFR is considered the gold standard for the evaluation of functionally relevant CAD. Therefore, an urgent need for non-invasive techniques that evaluate both the functional and morphological severity of CAD is growing. Coronary computed tomography angiography (CCTA) has emerged as a unique non-invasive technique providing coronary artery anatomic imaging. More recently, the evaluation of FFR with CCTA (FFRCT) has demonstrated high diagnostic performance compared to invasive FFR. Additionally, stress myocardial computed tomography perfusion (CTP) represents a novel tool for the diagnosis of ischemia with high diagnostic accuracy. Compared to nuclear imaging and cardiac magnetic resonance imaging, both FFRCT and stress-CTP, allow us to integrate the anatomical evaluation of coronary arteries with the functional relevance of coronary artery lesions having the potential to revolutionize the diagnostic paradigm of suspected CAD. FFRCT and stress-CTP could be assimilated in diagnostic pathways of patients with stable CAD and will likely result in a decrease of invasive diagnostic procedures and costs. The current review evaluates the technical aspects and clinical experience of FFRCT and stress-CTP in the evaluation of functionally relevant CAD discussing the strengths and weaknesses of each approach

Coronary artery disease : diagnostic accuracy of CT coronary angiography-a comparison of high and standard spatial resolution scanning

Purpose: To compare the image quality, evaluability, diagnostic accuracy, and radiation exposure of high-spatial-resolution (HR, 0.23-mm) computed tomographic (CT) coronary angiography with standard spatial resolution (SR, 0.625-mm) 64-section imaging in patients at high risk for coronary artery disease (CAD) by using invasive coronary angiography (ICA) as the reference method. Materials and Methods: Written informed consent was obtained from all patients, and the study protocol was approved by the institutional ethical committee. Patients at high risk for CAD (n = 184) who were scheduled for ICA were randomly assigned for study with SR (n = 91) or HR (n = 93) coronary CT angiography before they underwent ICA. To compare the two groups, the Student t test or Wilcoxon test were used to evaluate differences in continuous variables. The x2 test or Fisher exact test were used, as appropriate, for categorical data. The McNemar test was used to compare the diagnostic performance of coronary CT angiography versus that of ICA in each group. Results: HR coronary CT angiography showed a higher image quality score (3.7 vs 3.4, P,.001) and evaluability (97% vs 92%, P <.002). In a segment-based analysis, HR coronary CT angiography showed a higher specificity, positive predictive value, and accuracy in comparison with SR coronary CT angiography (98%, 91%, and 99% vs 95%, 80%, and 95%, respectively; P <.001). Moreover, HR coronary CT angiography showed a better agreement with ICA for calcified plaques compared with SR coronary CT angiography and ICA (83% vs 53%, P <.001). In a patient-based analysis, HR coronary CT angiography showed higher specificity and accuracy compared with SR coronary CT angiography (91% and 98% vs 46% and 92%, respectively; P <.01). No differences in radiation exposure were found between the two groups. Conclusion: Improved evaluability and accuracy were seen with HR compared with SR coronary CT angiography of calcified coronary artery lesions, suggesting a potential use for this technology in patients at high risk for CAD

Atrial Fibrillation: Diagnostic Accuracy of Coronary CT Angiography Performed with a Whole-Heart 230-mu m Spatial Resolution CT Scanner

Purpose: To assess image quality, interpretability, diagnostic accuracy, and radiation exposure of a computed tomography (CT) scanner with 16-cm coverage and 230-\uce\ubcm spatial resolution at coronary artery evaluation in patients with atrial fibrillation (AF) by using invasive coronary angiography (ICA) as the reference method and to compare the results with those obtained in patients with sinus rhythm (SR). Materials and Methods: Written informed consent and institutional ethics committee approval were obtained. Between March 2015 and February 2016, 166 consecutive patients were prospectively enrolled (83 with AF, 83 with SR). They underwent ICA and coronary CT angiography performed with a whole-heart CT scanner. Image quality, coronary segment interpretability, effective dose (ED), and diagnostic accuracy were assessed at CT angiography and were compared with those attained with ICA. Diagnostic performance of the groups was compared with the pairwise McNemar test. Results: Mean heart rate during scanning was 83 beats per minute \uc2\ub1 21 (standard deviation) in the AF group and 63 beats per minute \uc2\ub1 14 in the SR group (P<.01). Coronary interpretability was 98.5% in the AF group and 98.4% in the SR group (P = .96). In a segment-based analysis, sensitivity and specificity in the detection of coronary stenosis of more than 50% compared with detection of ICA were 96.4% and 98.7%, respectively, in the chronic AF group (P = .98) and 95.6% and 98.1%, respectively, in the SR group (P = .32). In a patient-based analysis, sensitivity and specificity were 95.2% and 97.6%, respectively, in the chronic AF group (P = .95) and 97.8% and 94.7%, respectively, in the SR group (P = .93). Conclusion: Whole-heart CT enables evaluation of coronary arteries with high image quality, low radiation exposure, and high diagnostic accuracy in patients with chronic AF, with a diagnostic performance similar to that in patients with SR

Low-dose CT coronary angiography with a novel intracyclemotion-correction algorithm in patients with high heart rate or heart rate variability

Aims: Motion artefacts due to high or irregular heart rate (HR) are common limitations of coronary computed tomography (CT) angiography (CCTA). The aim of the study was to evaluate the impact of a new motion-correction (MC) algorithm used in conjunction with low-dose prospective ECG-triggering CCTA on motion artefacts, image quality, and coronary assessability. Methods and results: Among 380 patients under going CCTA for suspected CAD, weselected 120 patients with pre-scanning HR.70 bpm or HR variability (HRv) >10 bpm during scanning irrespective of pre-scanning HR or both conditions. In patients with prescanning HR <65 or 6565 bpm, prospective ECG triggering with padding of 80 ms (58 cases) or padding of 200 ms (62 cases) was used, respectively. Mean pre-scanning HR and HRvwere 70\ub17 and 10.9\ub14 bpm, respectively. Overall, the mean effective dose was 3.4\ub11.3 mSv, while a lower dose (2.4\ub10.9 mSv) was measured for padding of 80 ms. In a segment-based analysis, coronary assessability was significantly higher (P < 0.0001) with MC (97%) when compared with standard (STD) reconstruction (81%) due to a significant reduction (P < 0.0001) in severe artefacts (54 vs. 356 cases, respectively). An artefact sub-analysis showed significantly lower number of motion artefacts and artefacts related to chest movement with MC (16 and 4 cases) than with STD reconstruction (286 and 24 cases, P < 0.0001 and P < 0.05, respectively). The number of coronary segments ranked among those of excellent image quality was significantly higher with MC (P < 0.001). Conclusions: The MC algorithm improves CCTA image quality and coronary assessability in patients with high HR and HRv, despite low radiation dose

Rationale and design of the PERFECTION (comparison between stress cardiac computed tomography PERfusion versus Fractional flow rEserve measured by Computed Tomography angiography In the evaluation of suspected cOroNary artery disease) prospective study

Background Non-invasive stress tests are commonly used as gatekeepers to invasive coronary angiography (ICA) in patients with suspected coronary artery disease (CAD). New computed tomography angiography (CTA) techniques such as fractional flow reserve calculated by CTA (FFRCT) and stress myocardial computed tomography perfusion (CTP) have emerged as potential strategies to combine anatomical and functional evaluation of CAD in one technique. The aim of this study is to compare per-vessel diagnostic accuracy of FFRCT versus stress myocardial CTP for the detection of functionally significant coronary artery disease (CAD), using invasive FFR as the reference standard. Methods Subjects with suspected CAD due to chest pain who have no contra-indications to FFRCT or stress myocardial CTP and who are referred for non-emergent, clinically indicated invasive coronary angiography (ICA), will be enrolled. A total of 300 subjects will be enrolled within 24 months. Results The primary study endpoint will be the comparison of per-vessel diagnostic accuracy of CTA versus FFRCT versus stress myocardial CTP for the diagnosis of hemodynamically significant stenosis as defined by invasive FFR 640.80. Conclusions In the PERFECTION study, the comparison between FFRCT and stress myocardial CTP will provide understanding about which technology is more accurate for the diagnosis of functionally significant CAD

The New Frontier of Cardiac Computed Tomography Angiography: Fractional Flow Reserve and Stress Myocardial Perfusion

The increased number of patients with coronary artery disease (CAD) in developed countries is of great clinical relevance and involves a large burden of the healthcare system. The management of these patients is focused on relieving symptoms and improving clinical outcomes. Therefore the ideal test would provide the correct diagnosis and actionable information. To this aim, several non-invasive functional imaging modalities are usually used as gatekeeper to invasive coronary angiography (ICA), but their diagnostic yield remains low with limited accuracy when compared to obstructive CAD at the time of ICA or invasive fractional flow reserve (FFR). Invasive FFR is considered the gold standard for the evaluation of functionally relevant CAD. Therefore, an urgent need for non-invasive techniques that evaluate both the functional and morphological severity of CAD is growing. Coronary computed tomography angiography (CCTA) has emerged as a unique non-invasive technique providing coronary artery anatomic imaging. More recently, the evaluation of FFR with CCTA (FFRCT) has demonstrated high diagnostic performance compared to invasive FFR. Additionally, stress myocardial computed tomography perfusion (CTP) represents a novel tool for the diagnosis of ischemia with high diagnostic accuracy. Compared to nuclear imaging and cardiac magnetic resonance imaging, both FFRCT and stress-CTP, allow us to integrate the anatomical evaluation of coronary arteries with the functional relevance of coronary artery lesions having the potential to revolutionize the diagnostic paradigm of suspected CAD. FFRCT and stress-CTP could be assimilated in diagnostic pathways of patients with stable CAD and will likely result in a decrease of invasive diagnostic procedures and costs. The current review evaluates the technical aspects and clinical experience of FFRCT and stress-CTP in the evaluation of functionally relevant CAD discussing the strengths and weaknesses of each approach

Impact of an intra-cycle motion correction algorithm on overall evaluability and diagnostic accuracy of computed tomography coronary angiography

Objectives: The aim of this study was to evaluate the impact of a novel intra-cycle motion correction algorithm (MCA) on overall evaluability and diagnostic accuracy of cardiac computed tomography coronary angiography (CCT). Methods: From a cohort of 900 consecutive patients referred for CCT for suspected coronary artery disease (CAD), we enrolled 160 (18\ua0%) patients (mean age 65.3 \ub1 11.7\ua0years, 101 male) with at least one coronary segment classified as non-evaluable for motion artefacts. The CCT data sets were evaluated using a standard reconstruction algorithm (SRA) and MCA and compared in terms of subjective image quality, evaluability and diagnostic accuracy. Results: The mean heart rate during the examination was 68.3 \ub1 9.4\ua0bpm. The MCA showed a higher Likert score (3.1 \ub1 0.9 vs. 2.5 \ub1 1.1, p < 0.001) and evaluability (94%vs.79\ua0%, p < 0.001) than the SRA. In a 45-patient subgroup studied by clinically indicated invasive coronary angiography, specificity, positive predictive value and accuracy were higher in MCA vs. SRA in segment-based and vessel-based models, respectively (87%vs.73\ua0%, 50%vs.34\ua0%, 85%vs.73\ua0%, p < 0.001 and 62%vs.28\ua0%, 66%vs.51\ua0% and 75%vs.57\ua0%, p < 0.001). In a patient-based model, MCA showed higher accuracy vs. SCA (93%vs.76\ua0%, p < 0.05). Conclusions: MCA can significantly improve subjective image quality, overall evaluability and diagnostic accuracy of CCT. Key Points: \u2022 Cardiac computed tomographic coronary angiography (CCT) allows non-invasive evaluation of coronary arteries \u2022 Intra-cycle motion correction algorithm (MCA) allows for compensation of coronary motion \u2022 An MCA improves image quality, CCT evaluability and diagnostic accurac