Impact of dexamethasone on the incidence of ventilator-associated pneumonia in mechanically ventilated COVID-19 patients: a propensity-matched cohort study.

OBJECTIVE: To assess the impact of treatment with steroids on the incidence and outcome of ventilator-associated pneumonia (VAP) in mechanically ventilated COVID-19 patients. DESIGN: Propensity-matched retrospective cohort study from February 24 to December 31, 2020, in 4 dedicated COVID-19 Intensive Care Units (ICU) in Lombardy (Italy). PATIENTS: Adult consecutive mechanically ventilated COVID-19 patients were subdivided into two groups: (1) treated with low-dose corticosteroids (dexamethasone 6 mg/day intravenous for 10 days) (DEXA+); (2) not treated with corticosteroids (DEXA-). A propensity score matching procedure (1:1 ratio) identified patients' cohorts based on: age, weight, PEEP Level, PaO2/FiO2 ratio, non-respiratory Sequential Organ Failure Assessment (SOFA) score, Charlson Comorbidity Index (CCI), C reactive protein plasma concentration at admission, sex and admission hospital (exact matching). INTERVENTION: Dexamethasone 6 mg/day intravenous for 10 days from hospital admission. MEASUREMENTS AND MAIN RESULTS: Seven hundred and thirty-nine patients were included, and the propensity-score matching identified two groups of 158 subjects each. Eighty-nine (56%) DEXA+ versus 55 (34%) DEXA- patients developed a VAP (RR 1.61 (1.26-2.098), p = 0.0001), after similar time from hospitalization, ICU admission and intubation. DEXA+ patients had higher crude VAP incidence rate (49.58 (49.26-49.91) vs. 31.65 (31.38-31.91)VAP*1000/pd), (IRR 1.57 (1.55-1.58), p < 0.0001) and risk for VAP (HR 1.81 (1.31-2.50), p = 0.0003), with longer ICU LOS and invasive mechanical ventilation but similar mortality (RR 1.17 (0.85-1.63), p = 0.3332). VAPs were similarly due to G+ bacteria (mostly Staphylococcus aureus) and G- bacteria (mostly Enterobacterales). Forty-one (28%) VAPs were due to multi-drug resistant bacteria. VAP was associated with almost doubled ICU and hospital LOS and invasive mechanical ventilation, and increased mortality (RR 1.64 [1.02-2.65], p = 0.040) with no differences among patients' groups. CONCLUSIONS: Critically ill COVID-19 patients are at high risk for VAP, frequently caused by multidrug-resistant bacteria, and the risk is increased by corticosteroid treatment. TRIAL REGISTRATION: NCT04388670, retrospectively registered May 14, 2020.

Machine learning insight into the role of imaging and clinical variables for the prediction of obstructive coronary artery disease and revascularization: An exploratory analysis of the CONSERVE study.

BACKGROUND: Machine learning (ML) is able to extract patterns and develop algorithms to construct data-driven models. We use ML models to gain insight into the relative importance of variables to predict obstructive coronary artery disease (CAD) using the Coronary Computed Tomographic Angiography for Selective Cardiac Catheterization (CONSERVE) study, as well as to compare prediction of obstructive CAD to the CAD consortium clinical score (CAD2). We further perform ML analysis to gain insight into the role of imaging and clinical variables for revascularization. METHODS: For prediction of obstructive CAD, the entire ICA arm of the study, comprising 719 patients was used. For revascularization, 1,028 patients were randomized to invasive coronary angiography (ICA) or coronary computed tomographic angiography (CCTA). Data was randomly split into 80% training 20% test sets for building and validation. Models used extreme gradient boosting (XGBoost). RESULTS: Mean age was 60.6 ± 11.5 years and 64.3% were female. For the prediction of obstructive CAD, the AUC was significantly higher for ML at 0.779 (95% CI: 0.672-0.886) than for CAD2 (0.696 [95% CI: 0.594-0.798]) (P = 0.01). BMI, age, and angina severity were the most important variables. For revascularization, the model obtained an overall area under the receiver-operation curve (AUC) of 0.958 (95% CI = 0.933-0.983). Performance did not differ whether the imaging parameters used were from ICA (AUC 0.947, 95% CI = 0.903-0.990) or CCTA (AUC 0.941, 95% CI = 0.895-0.988) (P = 0.90). The ML model obtained sensitivity and specificity of 89.2% and 92.9%, respectively. Number of vessels with ≥70% stenosis, maximum segment stenosis severity (SSS) and body mass index (BMI) were the most important variables. Exclusion of imaging variables resulted in performance deterioration, with an AUC of 0.705 (95% CI 0.614-0.795) (P <0.0001). CONCLUSIONS: For obstructive CAD, the ML model outperformed CAD2. BMI is an important variable, although currently not included in most scores. In this ML model, imaging variables were most associated with revascularization. Imaging modality did not influence model performance. Removal of imaging variables reduced model performance.

Selective Referral Using CCTA Versus Direct Referral for Individuals Referred to Invasive Coronary Angiography for Suspected CAD: A Randomized, Controlled, Open-Label Trial.

OBJECTIVES: This study compared the safety and diagnostic yield of a selective referral strategy using coronary computed tomographic angiography (CCTA) compared with a direct referral strategy using invasive coronary angiography (ICA) as the index procedure. BACKGROUND: Among patients presenting with signs and symptoms suggestive of coronary artery disease (CAD), a sizeable proportion who are referred to ICA do not have a significant, obstructive stenosis. METHODS: In a multinational, randomized clinical trial of patients referred to ICA for nonemergent indications, a selective referral strategy was compared with a direct referral strategy. The primary endpoint was noninferiority with a multiplicative margin of 1.33 of composite major adverse cardiovascular events (blindly adjudicated death, myocardial infarction, unstable angina, stroke, urgent and/or emergent coronary revascularization or cardiac hospitalization) at a median follow-up of 1-year. RESULTS: At 22 sites, 823 subjects were randomized to a selective referral and 808 to a direct referral strategy. At 1 year, selective referral met the noninferiority margin of 1.33 (p = 0.026) with a similar event rate between the randomized arms of the trial (4.6% vs. 4.6%; hazard ratio: 0.99; 95% confidence interval: 0.66 to 1.47). Following CCTA, only 23% of the selective referral arm went on to ICA, which was a rate lower than that of the direct referral strategy. Coronary revascularization occurred less often in the selective referral group compared with the direct referral to ICA (13% vs. 18%; p < 0.001). Rates of normal ICA were 24.6% in the selective referral arm compared with 61.1% in the direct referral arm of the trial (p < 0.001). CONCLUSIONS: In stable patients with suspected CAD who are eligible for ICA, the comparable 1-year major adverse cardiovascular events rates following a selective referral and direct referral strategy suggests that both diagnostic approaches are similarly effective. In the selective referral strategy, the reduced use of ICA was associated with a greater diagnostic yield, which supported the usefulness of CCTA as an efficient and accurate method to guide decisions of ICA performance. (Coronary Computed Tomographic Angiography for Selective Cardiac Catheterization [CONSERVE]; NCT01810198).

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] y old, 24 [16-34] kg, 37% female) admitted for acute lymphoblastic leukemia (80%), lymphoma (11%), and acute myeloid leukemia (7%). The induction propofol dose increased by 0.03 mg/kg per each procedure (P<0.05), from 2.6 (2.0-3.2) to 3.5 (2.6-4.3) mg/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.

Atrial Fibrillation: Diagnostic Accuracy of Coronary CT Angiography Performed with a Whole-Heart 230-µm 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-µm 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 ± 21 (standard deviation) in the AF group and 63 beats per minute ± 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. © RSNA, 2017 Online supplemental material is available for this article.

Additional value of inflammatory biomarkers and carotid artery disease in prediction of significant coronary artery disease as assessed by coronary computed tomography angiography.

AIMS: To evaluate the relationship between an incremental model including cardiovascular risk factors, carotid disease, and inflammatory biomarkers to predict the presence of obstructive coronary artery disease (CAD). METHODS AND RESULTS: A total of 134 consecutive and asymptomatic intermediate-risk patients (mean age 61 ± 9 years, 52% men) were enrolled. Each subject underwent circulating levels assessment of interleukin (IL)-2r, IL-6, IL-8, IL-10, high-sensitivity C-reactive protein (hs-CRP) and carotid and coronary artery evaluation using carotid ultrasound and coronary computed tomography angiography (CCTA), respectively. Carotid disease was diagnosed in 71 (53%) patients. Obstructive and multi-vessel CAD were found in 50 (37%) and 18 (14%) patients, respectively. Patients in whom CCTA showed multi-vessel CAD had a higher rate of carotid disease (89 vs. 46%, P = 0.001) and increased values of all interleukins when compared with patients without multi-vessel obstructive CAD. The univariate and multivariate analysis showed that male gender, diabetes, carotid disease, and IL-6 were independently associated with obstructive CAD. At receiver operating characteristic curve analysis, the multivariate model (including male gender, carotid disease, IL-6 > 5.9 pg/mL, and diabetes) showed the highest area under the curve for prediction of obstructive CAD, multi-vessel CAD, and high-risk plaque defined as mixed and/or remodelled plaque when compared with all other models (P < 0.001). CONCLUSION: Among asymptomatic intermediate-risk patients, the presence of increased IL6 levels in addition to traditional risk factors (male gender with diabetes) and carotid artery disease predicts higher rates of obstructive CAD and it could be of help to identify which subset of asymptomatic patients could be referred to CCTA for screening.

Left atrium and pulmonary vein imaging using sub-millisiviert cardiac computed tomography: Impact on radiofrequency catheter ablation cumulative radiation exposure and outcome in atrial fibrillation patients.

BACKGROUND: The outcome of radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) has improved thanks to left atrium (LA) anatomy reconstruction by cardiac computed tomography (CCT). A new model-based iterative reconstruction algorithm (MBIR) provides image noise reduction achieving effective radiation dose (ED) close to chest X-ray exposure. Aim of this study was comparing RFCA procedural characteristics, AF recurrence and radiation exposure between patients in whom RFCA was guided by CCT image integration with MBIR versus a CCT standard protocol. METHODS: Three-hundred consecutive patients with drug-refractory AF were studied with CCT using MBIR (Group 1; N:150) or CCT with standard protocol (Group 2; N:150) for LA evaluation and treated by image integration-supported RFCA. Image noise, signal to noise ratio (SNR), contrast to noise ratio (CNR), RFCA procedural characteristics, rate of AF recurrence and radiation exposure were compared. RESULTS: Group 1 showed higher SNR (25.9±7.1 vs. 16.2±4.8, p<0.001) and CNR (23.3±7.1 vs. 12.2±4.2, p<0.001) and lower image noise (22.3±5.2 vs. 32.6±8.1 HU, p<0.001), fluoroscopy time (21±12 vs. 29±15min, p<0.01) and procedural duration (135±89 vs. 172±55, p<0.001). Group 1 showed a 94% reduction of ED as compared to Group 2 (CCT-ED related: 0.41±0.04 vs. 6.17±4.11mSv, p<0.001; cumulative CCT+RFCA-ED related: 21.9±17.9 vs. 36.0±24.1mSv, p<0.001) with similar rate of AF recurrence (25% vs. 29%, p=0.437). CONCLUSIONS: CCT with MBIR allows accurate reconstruction of LA anatomy in AF patients undergoing RFCA with a sub-millisievert ED and comparable success rate of RFCA as compared to a standard CCT scan protocol.

The STRATEGY Study (Stress Cardiac Magnetic Resonance Versus Computed Tomography Coronary Angiography for the Management of Symptomatic Revascularized Patients): Resources and Outcomes Impact.

BACKGROUND: Computed tomography coronary angiography (cTCA) and stress cardiac magnetic resonance (stress-CMR) are suitable tools for diagnosing obstructive coronary artery disease in symptomatic patients with previous history of revascularization. However, performance appraisal of noninvasive tests must take in account the consequent diagnostic testing, invasive procedures, clinical outcomes, radiation exposure, and cumulative costs rather than their diagnostic accuracy only. We aimed to compare an anatomic (cTCA) versus a functional (stress-CMR) strategy in symptomatic patients with previous myocardial revascularization procedures. METHODS AND RESULTS: Six hundred patients with chest pain and previous revascularization included in a prospective observational registry and evaluated by clinically indicated cTCA (n=300, mean age 68.2±9.7 years, male 255) or stress-CMR (n=300, mean age 67.6±9.7 years, male 263) were enrolled and followed-up in terms of subsequent noninvasive tests, invasive coronary angiography, revascularization procedures, cumulative effective radiation dose, major adverse cardiac events, defined as a composite end point of nonfatal myocardial infarction and cardiac death, and medical costs. The mean follow-up for cTCA and stress-CMR groups was similar (773.6±345 versus 752.8±291 days; P=0.21). Compared with stress-CMR, cTCA was associated with a higher rate of subsequent noninvasive tests (28% versus 17%; P=0.0009), invasive coronary angiography (31% versus 20%; P=0.0009), and revascularization procedures (24% versus 16%; P=0.007). Stress-CMR strategy was associated with a significant reduction of radiation exposure and cumulative costs (59% and 24%, respectively; P<0.001). Finally, patients undergoing stress-CMR showed a lower rate of major adverse cardiac events (5% versus 10%; P<0.010) and cost-effectiveness ratio (119.98±250.92 versus 218.12±298.45 Euro/y; P<0.001). CONCLUSIONS: Compared with cTCA, stress-CMR is more cost-effective in symptomatic revascularized patients.

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

OPINION STATEMENT: 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.

Prognostic Benefit of Cardiac Magnetic Resonance Over Transthoracic Echocardiography for the Assessment of Ischemic and Nonischemic Dilated Cardiomyopathy Patients Referred for the Evaluation of Primary Prevention Implantable Cardioverter-Defibrillator Therapy.

BACKGROUND: The aim of this study was to determine the prognostic benefit of cardiac magnetic resonance (CMR) over transthoracic echocardiography (TTE) in ischemic cardiomyopathy and nonischemic dilated cardiomyopathy patients evaluated for primary prevention implantable cardioverter-defibrillator therapy. METHODS AND RESULTS: We enrolled 409 consecutive ischemic and dilated cardiomyopathy patients (mean age: 64±12 years; 331 men). All patients underwent TTE and CMR, and left ventricle end-diastolic volume, left ventricle end-systolic volume, and left ventricle ejection fraction (LVEF) were evaluated. In addition, late gadolinium enhancement was also assessed. All patients were followed up for major adverse cardiac events (MACE) defined as a composite end point of long runs of nonsustained ventricular tachycardia, sustained ventricular tachycardia, aborted sudden cardiac death, or sudden cardiac death. The median follow-up was 545 days. CMR showed higher left ventricle end-diastolic volume (mean difference: 43±22.5 mL), higher left ventricle end-systolic volume (mean difference: 34±20.5 mL), and lower LVEF (mean difference: -4.9±10%) as compared to TTE (P<0.01). MACE occurred in 103 (25%) patients. Patients experiencing MACE showed higher left ventricle end-diastolic volume, higher left ventricle end-systolic volume, and lower LVEF with both imaging modalities and higher late gadolinium enhancement per-patient prevalence as compared to patients without MACE. At multivariable analysis, CMR-LVEF ≤35% (hazard ratio=2.18 [1.3-3.8]) and the presence of late gadolinium enhancement (hazard ratio=2.2 [1.4-3.6]) were independently associated with MACE (P<0.01). A model based on CMR-LVEF ≤35% or CMR-LVEF ≤35% plus late gadolinium enhancement detection showed a higher performance in the prediction of MACE as compared to TTE-LVEF resulting in net reclassification improvement of 0.468 (95% confidence interval, 0.283-0.654; P<0.001) and 0.413 (95% confidence interval, 0.23-0.63; P<0.001), respectively. CONCLUSIONS: CMR provides additional prognostic stratification as compared to TTE, which may have direct impact on the indication of implantable cardioverter-defibrillator implantation.

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 ≤0.80. 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.

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 %) patients (mean age 65.3 ± 11.7 years, 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 ± 9.4 bpm. The MCA showed a higher Likert score (3.1 ± 0.9 vs. 2.5 ± 1.1, p < 0.001) and evaluability (94%vs.79 %, 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 %, 50%vs.34 %, 85%vs.73 %, p < 0.001 and 62%vs.28 %, 66%vs.51 % and 75%vs.57 %, p < 0.001). In a patient-based model, MCA showed higher accuracy vs. SCA (93%vs.76 %, p < 0.05). CONCLUSIONS: MCA can significantly improve subjective image quality, overall evaluability and diagnostic accuracy of CCT. KEY POINTS: Cardiac computed tomographic coronary angiography (CCT) allows non-invasive evaluation of coronary arteries. Intra-cycle motion correction algorithm (MCA) allows for compensation of coronary motion. An MCA improves image quality, CCT evaluability and diagnostic accuracy.

Prognostic value of dipyridamole stress cardiac magnetic resonance in patients with known or suspected coronary artery disease: a mid-term follow-up study.

OBJECTIVES: Dipyridamole stress cardiac magnetic resonance (CMR) evaluates the key phases (perfusion and wall motion) of the ischemic cascade. We sought to determine the prognostic value of dipyridamole stress-CMR in consecutive patients symptomatic for chest pain. METHODS: Seven hundred and ninety-three consecutive patients symptomatic for chest pain underwent dipyridamole stress-CMR and were followed up for 810 ± 665 days. Patients were classified in group 1 (no- reversible ischemia), group 2 (stress perfusion defect alone), and group 3 [stress perfusion defect plus abnormal wall motion (AWM)]. End points were "all cardiac events" (myocardial infarction, cardiac death and revascularization) and "hard cardiac events" (all cardiac events excluding revascularization). RESULTS: One hundred and ninety-five (24 %) all cardiac events and 53 (7 %) hard cardiac events were observed. All and hard cardiac event rates in groups 1, 2, and 3 were 11 %, 49 %, 69 % and 4 %, 8 %, 21 %, respectively, with a higher rate in group 2 vs. group 1 (p<0.01) and group 3 vs. groups 1 and 2 (p<0.01). Multivariate analysis showed the presence of late gadolinium enhancement and stress perfusion defect plus AWM as independent predictors of all and hard cardiac events. CONCLUSIONS: Dipyridamole stress-CMR improves prognostic stratification of patients through differentiation between the different components of the ischemic cascade. KEY POINTS: • Dipyridamole stress cardiac magnetic resonance helps to assess coronary artery disease. • Novel technique to study the key phases of myocardial ischemia. • Combined assessment of perfusion and motion defects. • Dipyridamole stress imaging has additional value for predicting cardiac events.

Low-dose CT coronary angiography with a novel IntraCycle motion-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 undergoing CCTA for suspected CAD, we selected 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 pre-scanning HR <65 or ≥65 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 HRv were 70 ± 7 and 10.9 ± 4 bpm, respectively. Overall, the mean effective dose was 3.4 ± 1.3 mSv, while a lower dose (2.4 ± 0.9 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.

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.

Comparison of cardiac computed tomography versus cardiac magnetic resonance for characterization of left atrium anatomy before radiofrequency catheter ablation of atrial fibrillation.

BACKGROUND: The outcome of radiofrequency catheter ablation (RFCA) has been improved by the pivotal role of cardiovascular imaging such as cardiac computed tomography (CCT) or cardiac magnetic resonance (CMR) for the characterization of left atrium (LA) anatomy before RFCA. The aim of this study is to compare the procedural characteristics, overall radiation exposure and clinical outcomes between RFCA guided by image integration with CCT versus CMR. METHODS: Four-hundred patients with drug-refractory paroxysmal or persistent AF referred to RCFA were matched with the propensity score matching analysis to CCT (n: 200) or CMR (n: 200) for evaluation of LA before RFCA procedure. Left atrium diameter, left atrium volume, variant of pulmonary veins' anatomy, pulmonary veins' ostial dimensions, procedural characteristics, overall radiation exposure and rate of AF recurrence after RFCA were measured and compared between the two groups. RESULTS: The 2 groups were homogeneous with similar follow-up (557 ± 302 vs. 523 ± 265 days, respectively, p:0.24). The CCT group showed higher LA volume vs. CMR group (117 ± 46 vs. 101 ± 40 mL, p<0.001). No differences were observed regarding procedural characteristics. AF recurrence at follow-up was similar (29% vs. 26%, p:0.5) despite a higher radiation exposure in the CCT group vs. CMR group (40.4 ± 23.7 mSv vs. 32.8 ± 23.5 mSv, p<0.005). LA volume detected by CMR was the most robust independent predictor of AF recurrence at multivariate analysis [(HR: 1.08 (1.01-1.15), p: 0.02]. CONCLUSIONS: CCT and CMR provide similar information before RFCA. However, RFCA CMR-guided is associated with a lower overall cumulative radiation despite similar outcome in comparison with CCT-guided RFCA.

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 χ(2) 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.

Comparison of accuracy of aortic root annulus assessment with cardiac magnetic resonance versus echocardiography and multidetector computed tomography in patients referred for transcatheter aortic valve implantation.

The evaluation of the aortic root in patients referred for transcatheter aortic valve implantation is crucial. The aim of the present study was to compare the accuracy of cardiac magnetic resonance (CMR) evaluation of the aortic annulus (AoA) with transthoracic and transesophageal echocardiography and multidetector computed tomography (MDCT) in patients referred for transcatheter aortic valve implantation. In 50 patients, maximum diameter, minimum diameter and AoA, length of the left coronary, right coronary, and noncoronary aortic leaflets, degree (grades 1 to 4) of aortic leaflet calcification, and distance between AoA and coronary artery ostia were assessed. AoA maximum diameter, minimum diameter, and area by CMR were 26.4 ± 2.8 mm, 20.6 ± 2.3 mm, 449.8 ± 86.2 mm(2), respectively. The length of left coronary, right coronary, and noncoronary leaflets by CMR were 13.9 ± 2.2, 13.3 ± 2.1, and 13.4 ± 1.8 mm, respectively, whereas the score of aortic leaflet calcifications was 2.9 ± 0.8. Finally, the distances between AoA and left main and right coronary artery ostia were 16.1 ± 2.8 and 16.1 ± 4.4 mm, respectively. Regarding AoA area, transthoracic and transesophageal echocardiography showed an underestimation (p <0.01), with a moderate agreement (r: 0.5 and 0.6, respectively, p <0.01) compared with CMR. No differences and excellent correlation were observed between CMR and MDCT for all parameters (r: 0.9, p <0.01), except for aortic leaflet calcifications that were underestimated by CMR. In conclusion, aortic root assessment with CMR including AoA size, aortic leaflet length, and coronary artery ostia height is accurate compared with MDCT. CMR may be a valid imaging alternative in patients unsuitable for MDCT.