Multiparametric Mapping via Cardiovascular Magnetic Resonance in the Risk Stratification of Ventricular Arrhythmias and Sudden Cardiac Death.

Risk stratification for malignant ventricular arrhythmias and sudden cardiac death is a daunting task for physicians in daily practice. Multiparametric mapping sequences obtained via cardiovascular magnetic resonance imaging can improve the risk stratification for malignant ventricular arrhythmias by unveiling the presence of pathophysiological pro-arrhythmogenic processes. However, their employment in clinical practice is still restricted. The present review explores the current evidence supporting the association between mapping abnormalities and the risk of ventricular arrhythmias in several cardiovascular diseases. The key message is that further clinical studies are needed to test the additional value of mapping techniques beyond conventional cardiovascular magnetic resonance imaging for selecting patients eligible for an implantable cardioverter defibrillator.

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.

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.

Diagnostic accuracy of multidetector computed tomography coronary angiography in 325 consecutive patients referred for transcatheter aortic valve replacement.

BACKGROUND: Multidetector computed tomography (MDCT) provides detailed assessment of valve annulus and iliofemoral vessels in transcatheter aortic valve replacement (TAVR) patients. However, data on diagnostic performance of MDCT coronary angiography (MDCT-CA) are scarce. The aim of the study is to assess diagnostic performance of MDCT for coronary artery evaluation before TAVR. METHODS: A total of 325 consecutive patients (234 without previous myocardial revascularization, 49 with previous coronary stenting, and 42 with previous coronary artery bypass graft [CABG]) underwent invasive coronary angiography and MDCT before TAVR. MDCT-CA was performed using the same data set dedicated to standard MDCT aortic annulus evaluation. Multidetector computed tomography-CA evaluability and diagnostic accuracy in comparison with invasive coronary angiography as criterion standard were assessed. RESULTS: The MDCT-CA evaluability of native coronaries was 95.6%. The leading cause of unevaluability was beam-hardening artifact due to coronary calcifications. In a segment-based analysis, MDCT-CA showed sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for detecting ≥50% stenosis of 91%, 99.2%, 83.4%, 99.6% and 98.8%, respectively. The MDCT-CA evaluability of coronary stents was 82.1%. In a segment-based analysis, MDCT-CA showed sensitivity, specificity, PPV, NPV, and accuracy for detecting ≥50% in-stent restenosis of 94.1%, 86.7%, 66.7%, 98.1%, and 88.3%, respectively. All CABGs were correctly assessed by MDCT-CA. In a patient-based analysis, MDCT-CA showed sensitivity, specificity, PPV, NPV, and accuracy of 89.7%, 90.8%, 80.6%, 95.4%, and 90.5%, respectively. CONCLUSIONS: Multidetector computed tomography-CA allows to correctly rule out the presence of significant native coronary artery stenosis, significant in-stent restenosis, and CABG disease in patients referred for TAVR.

[Role of multimodality imaging in patients undergoing transcatheter aortic valve implantation]. / Ruolo dell'imaging multimodale nei pazienti candidati ad impianto di valvola aortica percutanea.

Aortic stenosis is a common disorder. Aortic valve replacement is indicated for symptomatic patients with severe aortic stenosis, as the prognosis of untreated patients is poor. However, despite aortic valve replacement can produce dramatic benefit in the setting of aortic stenosis, morbidity and mortality associated with surgery has fostered a search for alternatives. Transcatheter aortic valve replacement is a novel method to treat selected high-risk patients with aortic stenosis. Patient screening and anatomic measurements of the aortic root, aortic cusp heights, and the distance between aortic annulus and coronary ostia, as well as the evaluation of coronary arteries and peripheral arterial disease are of great importance to ensure procedural success . This review outlines the evolving role of non-invasive multimodality imaging, including echocardiography, multidetector computed tomography and cardiac magnetic resonance, in support of transcatheter aortic valve implantation, and describes how the multimodality imaging approach is crucial in this clinical setting.

Coronary in-stent restenosis: assessment with CT coronary angiography.

PURPOSE: To compare accuracy and radiation exposure of a new computed tomographic (CT) scanner with improved spatial resolution (scanner A) with those of a CT scanner with standard spatial resolution (scanner B) for evaluation of coronary in-stent restenosis (ISR) by using invasive coronary angiography (ICA) and intravascular ultrasonography (US) as reference methods. MATERIALS AND METHODS: Written informed consent was obtained and study protocol was approved by institutional ethics committee. A total of 180 consecutive patients (154 men [mean age ± standard deviation, 66 years±12; range, 51-79 years] and 36 women [mean age, 70 years±12; range, 55-83 years]) scheduled to undergo ICA for suspected ISR were enrolled. Ninety patients were studied with scanner A (group 1: 72 men [mean age, 65 years±11; range, 52-79], 18 women [mean age, 68 years±12; range, 55-83 years]) and 90 with scanner B (group 2: 74 men [mean age, 64 years±10; range, 51-77 years], 16 women [mean age, 68 years±11; range, 55-82 years). Examination with the two scanners was compared with ICA and intravascular US. Radiation dose exposure was estimated. To compare stent evaluability between the two groups, χ2 test was used. RESULTS: Stent evaluability was higher in group 1 than in group 2 (99% vs 92%, P=.0021). A significantly lower rate of beam-hardening artifact was observed in group 1 (two cases) than group 2 (12 cases, P<.05). For stent-based analysis, sensitivity, specificity, and accuracy of multidetector CT for ISR identification were 96%, 95%, and 96% in group 1 and 90%, 91%, and 91% in group 2, respectively, without statistically significant differences. The correlation between percent ISR evaluated at multidetector CT versus intravascular US was higher in group 1 than in group 2 (r=0.89 vs r=0.58; P=.019). The correlations of diameter and area measurements at reference site and stent maximal lumen narrowing site between multidetector CT and intravascular US were higher in group 1 than in group 2. Radiation dose was low in both multidetector CT groups (1.9 mSv±0.2). CONCLUSION: Scanner A, with improved spatial resolution, allowed reliable detection and quantification of coronary ISR with low radiation exposure.

Aortic annulus area assessment by multidetector computed tomography for predicting paravalvular regurgitation in patients undergoing balloon-expandable transcatheter aortic valve implantation: a comparison with transthoracic and transesophageal echocardiography.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) is a valid alternative to surgery in high-risk patients with severe aortic stenosis. Aortic annulus (AoA) sizing is crucial for TAVI success. The aim of the study was to compare AoA dimensions measured by multidetector computed tomography (MDCT) vs those obtained with transthoracic (TTE) and transesophageal echocardiography (TEE) for predicting paravalvular aortic regurgitation (PVR) after TAVI. METHODS: Aortic annulus maximum diameter, minimum diameter, and area were assessed using MDCT and compared with TTE and TEE diameter and area for predicting PVR after TAVI in 151 patients (45 men, age 81.2 ± 6.4 years). RESULTS: Aortic annulus maximum, minimum diameter, and area detected by MDCT were 25.04 ± 2.39 mm, 21.27 ± 2.10 mm, and 420.87 ± 76.10 mm(2), respectively. Aortic annulus diameter and area measured by TTE and TEE were 21.14 ± 1.94 mm and 353.82 ± 64.57 mm(2) and 22.04 ± 1.94 mm and 384.33 ± 67.30 mm(2), respectively. A good correlation was found between AoA diameters and area evaluated by MDCT vs TTE and TEE (0.61, 0.65, and 0.69 and 0.61, 0.65, and 0.70, respectively), with a mean difference of 3.90 ± 1.98 mm, 0.13 ± 1.67 mm, and 67.05 ± 55.87 mm(2) and 3.0 ± 2.0 mm, 0.77 ± 1.70 mm, and 36.54 ± 56.43 mm(2), respectively. Grade ≥2 PVR occurred in 46 patients and was related to male gender, higher body mass index, preprocedural aortic regurgitation, and lower mismatch between the nominal area of the implanted prosthesis and AoA area detected by MDCT. CONCLUSIONS: Mismatch between prosthesis area and AoA area detected by MDCT is a better predictor of PVR as compared with echocardiography mismatch. Specific MDCT-based sizing recommendations should be developed.

Feasibility and accuracy of a comprehensive multidetector computed tomography acquisition for patients referred for balloon-expandable transcatheter aortic valve implantation.

BACKGROUND: The aim of this study was to assess the accuracy of a comprehensive multidetector computed tomography (MDCT) evaluation of the aortic annulus (AoA), coronary artery disease (CAD), and peripheral vessels in patients referred for transcatheter aortic valve implantation (TAVI). METHODS: In 60 patients referred for TAVI, the following parameters were assessed with 64-slices MDCT and compared with transesophageal echocardiography (TEE), invasive coronary angiography (ICA), and peripheral angiography: AoA maximum diameter (Max-AoA-D(MDCT)), minimum diameter (Min-AoA-D(MDCT)), and area; lumen morphology index ([Max-AoA-D(MDCT)/Min-AoA-D(MDCT)]); length of the left, right, and non-coronary aortic leaflets; degree (grades 1-4) of aortic leaflet calcifications; distance between AoA and left main coronary ostium and between AoA and right coronary ostium CAD and peripheral vessel disease. RESULTS: The Max-AoA-D(MDCT) and Min-AoA-D(MDCT) were 25.1 ± 2.8 and 21.2 ± 2.2 mm, respectively, with high correlation versus AoA diameter measured with TEE (r = 0.82 and 0.86, respectively). The area of AoA, systolic and diastolic lumen morphology index were 410 ± 81.5 mm(2), 1.19 ± 0.1 and 1.22 ± 0.11, respectively. Aortic leaflet calcification score was 3.3 ± 0.5. The lengths of left, right, and non-coronary aortic leaflets were 14.2 ± 2.4, 13.7.1 ± 2.1, and 14.5 ± 2.6 mm, whereas distances between AoA and the left main coronary ostium and between AoA, and the right coronary ostium were 13.7 ± 2.9 and 15.8 ± 3.5 mm, respectively. Feasibility, negative predictive value, and accuracy for CAD detection versus ICA were 87%, 100% (CI 100-100), and 96% (95% CI 94-100), respectively. All patients (N = 17) who were ineligible for TAVI were correctly detected by MDCT. CONCLUSIONS: A comprehensive MDCT evaluation of patients referred for TAVI is feasible, provides more accurate assessment than TEE of AoA morphology, and may replace peripheral angiography in all patients and ICA in patients without significant CAD.

High diagnostic accuracy of prospective ECG-gating 64-slice computed tomography coronary angiography for the detection of in-stent restenosis: in-stent restenosis assessment by low-dose MDCT.

OBJECTIVES: The accuracy of computed tomography (CT) for assessment of coronary stents is as yet unproven and radiation exposure has been a concern. The aim of our study is to compare radiation dose and diagnostic performance of CT with prospective ECG-triggering versus retrospective ECG-triggering for the detection of in-stent restenosis (ISR). METHODS: We enrolled 168 consecutive patients with suspected ISR, 83 studied using CT with prospective ECG-triggering (group 1) and 85 using retrospective ECG-triggering (group 2). RESULTS: Prevalence of ISR according to catheter angiography was 24% in both groups. The overall evaluability was similar (93% in group 1 vs 95% in group 2). Artefact sub-analysis showed a significantly lower number of blooming and higher number of slice misalignment in group 1 vs group 2. In the stent-based analysis using only evaluable stents, specificity, positive predictive value and accuracy were significantly higher in group 1 (100%, 100% and 99%, respectively) than in group 2 (97%, 91% and 95%, respectively, p < 0.05). Group 1 was exposed to a lower radiation dose compared with group 2 (4.3 ± 1.4 mSv vs 18.5 ± 5.5 mSv, p < 00.1). CONCLUSIONS: CT with prospective ECG-triggering can improve diagnostic accuracy of non-invasive imaging of coronary stents with a significant reduction in radiation exposure.

[Role of the multidetector computed tomography for noninvasive evaluation of ischemic heart disease]. / Ruolo della tomografia computerizzata multidetettore nella valutazione della cardiopatia ischemica: principî tecnologici e applicazioni cliniche.

The anatomical evaluation of the coronary arteries, the clinical indication for revascularization procedure and followup of patients has always been prerogative of invasive coronary angiography. However this technique has several disvantages. First, it is invasive and associated with a not neglegible incidence of adverse events. Second, it is expensive and last the information obtained via catheter-based coronary angiography pertains to the coronary arterial lumen alone.The introduction of multidetector computed tomography scanner associated with high-speed and ECG-gated x-ray tube allowed an increase in spatial and temporal resolution such as to consider this technology a valuable alternative to the invasive coronary angiography. The aim of this review is to describe tecnical background, clinical applications and issues of radiation exposure of this new promising diagnostic method.

[ANMCO/SICI-GISE/SIC/SIECVI/SIRM Consensus document: Appropriateness of multimodality imaging in cardiovascular disease]. / Documento di consenso ANMCO/SICI-GISE/SIC/SIECVI/SIRM: Appropriatezza dell'imaging multimodale nelle patologie cardiovascolari.

The complexity of cardiovascular diseases has led to an extensive use of technological instruments and the development of multimodality imaging. This extensive use of different cardiovascular imaging tests in the same patient has increased costs and waiting times.The concept of appropriateness has changed over time. Appropriateness criteria address the need for specific cardiovascular imaging tests in well-defined clinical scenarios, and define the kind of cardiovascular imaging that is appropriated for each clinical scenario in different stages of the disease. The concept of appropriateness criteria has replaced the old idea of appropriate use criteria and reflects the increasing effort of the international Scientific Societies to create and review in a critical way the management of diagnostic tests used by clinicians.The aim of this Italian consensus document is to address the use of multimodality imaging in the diagnosis and management of the major cardiovascular clinical scenarios, taking into consideration not only the international guidelines and scientific documents already published, but also the reality of Italian laws as well as the various professional profiles involved in patient management and availability of technological diagnostic instruments.

Permanent atrial fibrillation affects exercise capacity in chronic heart failure patients.

AIMS: The influence of permanent atrial fibrillation on exercise tolerance and cardio-respiratory function during exercise in heart failure (HF) is unknown. METHODS AND RESULTS: We retrospectively compared the results of 942 cardiopulmonary exercise tests, performed consecutively at seven Italian laboratories, in HF patients with atrial fibrillation (n = 180) and sinus rhythm (n = 762). By multivariable logistic regression analysis, peak VO(2) (OR 0.376, 95% CI 0.240-0.588, P < 0.0001), O(2)pulse (VO(2)/heart rate, HR) (OR 0.236, 95% CI 0.152-0.366, P < 0.0001), VCO(2) (OR 3.97, 95% CI 2.163-7.287, P < 0.0001), and ventilation (OR 1.38, 95% CI 1.045-1.821, P = 0.0231) were independently associated with atrial fibrillation. Anaerobic threshold (AT) was identified in 132 of 180 (73%) atrial fibrillation and in 649 of 762 (85%) sinus rhythm patients (P = 0.0002). By multivariable logistic regression analysis, only peak VO(2) (OR 0.214, 95% CI 0.155-0.296, P < 0.0001) was independently associated with unidentified AT. At AT, atrial fibrillation HF patients had higher HR (P < 0.0001) and higher VO(2) (P < 0.001) compared with sinus rhythm HF patients. Among AT variables, by multivariable logistic regression analysis, only HR was an independent predictor of atrial fibrillation. CONCLUSION: In HF patients with permanent atrial fibrillation, exercise performance is reduced as reflected by reduced peak VO(2). The finding of unidentified AT is associated with a poor performance. In atrial fibrillation patients, VO(2) is higher at AT whereas lower at peak. This last observation raises uncertainties about the use of AT data to define performance and prognosis of HF patients with atrial fibrillation.

Congenital absence of pericardium: two cases and a comprehensive review of the literature.

Congenital absence of pericardium (CAP) is a rare condition, generally asymptomatic or paucisymptomatic, nevertheless sporadic cases complicated by sudden death are described. CAP can be diagnosed by CT and MRI. It is classified as total or partial, and partial defects are divided into left defects and right defects. Interestingly, several articles highlight the correlation between CAP and some anatomical lung abnormalities, such as presence of lung parenchyma between the main pulmonary artery and ascending aorta, lung parenchyma between the base of the heart and left hemidiaphragm, and lung parenchyma between the proximal ascending aorta and right pulmonary artery.

[Role of multimodality imaging in the clinical evaluation of hypertrophic cardiomyopathy]. / Valutazione clinica della cardiomiopatia ipertrofica: ruolo dell'imaging multimodale.

Sarcomeric hypertrophic cardiomyopathy is the most common cardiovascular genetic disease. Clinical evaluation and comprehensive echocardiography are crucial for the diagnosis and early evaluation of the hypertrophic phenotype, but multimodality imaging approach is often required to better define diagnosis and differential diagnosis from phenocopies. This review aims to assess the role of multimodality imaging and, in particular, advanced echocardiography and cardiac magnetic resonance in relation to differential diagnosis and preclinical diagnosis, identification of different phenotypes, and assessment of disease progression and risk of sudden cardiac death. A multimodality imaging approach is also crucial for the selection of patients amenable to surgical or percutaneous septal myectomy and for guiding both procedures.

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.

Long-term prognostic effect of coronary atherosclerotic burden: validation of the computed tomography-Leaman score.

BACKGROUND: Computed tomography-adapted Leaman score (CT-LeSc) was developed to quantify coronary CT angiography information about atherosclerotic burden (lesion localization, stenosis degree, and plaque composition). The objective of the study is to evaluate CT-LeSc long-term prognostic value in patients with suspected coronary artery disease (CAD). METHODS AND RESULTS: Single-center prospective registry including 1304 consecutive patients undergoing coronary CT angiography for suspected CAD. High CT-LeSc was defined by upper tertile (score, >5) cutoff. Segment involvement score and segment stenosis score were also evaluated. Hard cardiac events (cardiac death and nonfatal acute coronary syndromes) were considered for analysis. Different Cox regression models were used to identify independent event predictors. Kaplan-Meier event-free survival was evaluated in 4 patient subgroups stratified by obstructive (≥50% stenosis) versus nonobstructive CAD and a high (>5) versus a low (≤5) CT-LeSc. Of 1196 patients included in the final analysis (mean follow-up of 52±22 months), 125 patients experienced 136 hard events (18 cardiac deaths and 118 nonfatal myocardial infarction). All atherosclerotic burden scores were independent predictors of cardiac events (hazard ratios of 3.09 for segment involvement score, 4.42 for segment stenosis score, and 5.39 for CT-LeSc). Cumulative event-free survival was 76.8% with a high CT-LeSc and 96.0% with a low CT-LeSc. Event-free survival in nonobstructive CAD with high CT-LeSc (78.6%) was similar to obstructive CAD with high CT-LeSc (76.5%) but lower than obstructive CAD with low CT-LeSc (80.7%). CONCLUSIONS: CT-LeSc is an independent long-term predictor of hard cardiac events. Patients with nonobstructive CAD and high CT-LeSc had hard event-free survival similar to patients with obstructive CAD.

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.

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.