Cardiovascular magnetic resonance images with susceptibility artifacts: artificial intelligence with spatial-attention for ventricular volumes and mass assessment.

BACKGROUND: Segmentation of cardiovascular magnetic resonance (CMR) images is an essential step for evaluating dimensional and functional ventricular parameters as ejection fraction (EF) but may be limited by artifacts, which represent the major challenge to automatically derive clinical information. The aim of this study is to investigate the accuracy of a deep learning (DL) approach for automatic segmentation of cardiac structures from CMR images characterized by magnetic susceptibility artifact in patient with cardiac implanted electronic devices (CIED). METHODS: In this retrospective study, 230 patients (100 with CIED) who underwent clinically indicated CMR were used to developed and test a DL model. A novel convolutional neural network was proposed to extract the left ventricle (LV) and right (RV) ventricle endocardium and LV epicardium. In order to perform a successful segmentation, it is important the network learns to identify salient image regions even during local magnetic field inhomogeneities. The proposed network takes advantage from a spatial attention module to selectively process the most relevant information and focus on the structures of interest. To improve segmentation, especially for images with artifacts, multiple loss functions were minimized in unison. Segmentation results were assessed against manual tracings and commercial CMR analysis software cvi42(Circle Cardiovascular Imaging, Calgary, Alberta, Canada). An external dataset of 56 patients with CIED was used to assess model generalizability. RESULTS: In the internal datasets, on image with artifacts, the median Dice coefficients for end-diastolic LV cavity, LV myocardium and RV cavity, were 0.93, 0.77 and 0.87 and 0.91, 0.82, and 0.83 in end-systole, respectively. The proposed method reached higher segmentation accuracy than commercial software, with performance comparable to expert inter-observer variability (bias ± 95%LoA): LVEF 1 ± 8% vs 3 ± 9%, RVEF - 2 ± 15% vs 3 ± 21%. In the external cohort, EF well correlated with manual tracing (intraclass correlation coefficient: LVEF 0.98, RVEF 0.93). The automatic approach was significant faster than manual segmentation in providing cardiac parameters (approximately 1.5 s vs 450 s). CONCLUSIONS: Experimental results show that the proposed method reached promising performance in cardiac segmentation from CMR images with susceptibility artifacts and alleviates time consuming expert physician contour segmentation.

Multi-modality imaging assessment of native valvular regurgitation: an EACVI and ESC council of valvular heart disease position paper.

Valvular regurgitation represents an important cause of cardiovascular morbidity and mortality. Imaging is pivotal in the evaluation of native valve regurgitation and echocardiography is the primary imaging modality for this purpose. The imaging assessment of valvular regurgitation should integrate quantification of the regurgitation, assessment of the valve anatomy and function, and the consequences of valvular disease on cardiac chambers. In clinical practice, the management of patients with valvular regurgitation largely relies on the results of imaging. It is crucial to provide standards that aim at establishing a baseline list of measurements to be performed when assessing native valve regurgitation. The present document aims to present clinical guidance for the multi-modality imaging assessment of native valvular regurgitation.

Plaque assessment by coronary CT angiography may predict cardiac events in high risk and very high risk diabetic patients: A long-term follow-up study.

BACKGROUND AND AIMS: The aim of the present study is to evaluate whether advanced coronary atherosclerosis analysis by CCTA may improve prognostic stratification among diabetic patients at high cardiovascular risk (CV risk). METHODS AND RESULTS: The study population consisted of 265 consecutive diabetic patients at high CV risk who underwent CCTA for suspected CAD between January 2011 and December 2016. For every patients both traditional and advanced, qualitative and quantitative coronary plaque analysis were performed. The occurrence of cardiac death, ACS, and non-urgent revascularization were recorded at follow-up. Among the 265 patients enrolled, 21 were lost to follow-up, whereas 244 (92%) had a complete follow-up (mean 45 ± 22 months) and were classified at high (n = 67) or very high cardiovascular risk (n = 177), according to ESC Guidelines. A total of 63 events were recorded (3 Cardiac Death, 3 NSTEMI, 8 unstable angina, 36 late non-urgent revascularization and 13 non-cardiac death) in 57 different patients. Elevated fibro-fatty plaque volume was the only predictor of events over age, gender and traditional risk factor when ACS and MACE were considered as end-points [HR (95% CI) 6.01 (1.65-21.87), p = 0.006 and 3.46 (2.00-5.97); p < 0.001]. CONCLUSION: The present study confirms the prognostic role of advance coronary atherosclerosis evaluation beyond risk factors and stenosis severity, even in diabetics. Despite the very high cardiovascular risk of study population, a not negligible portion (23%) of patients exhibited totally normal coronaries.

Multimodality imaging assessment of mitral annular disjunction in mitral valve prolapse.

OBJECTIVE: Mitral annular disjunction (MAD) is an abnormality linked to mitral valve prolapse (MVP), possibly associated with malignant ventricular arrhythmias. We assessed the agreement among different imaging techniques for MAD identification and measurement. METHODS: 131 patients with MVP and significant mitral regurgitation undergoing transthoracic echocardiography (TTE) and cardiac magnetic resonance (CMR) were retrospectively enrolled. Transoesophageal echocardiography (TOE) was available in 106 patients. MAD was evaluated in standard long-axis views (four-chamber, two-chamber, three-chamber) by each technique. RESULTS: Considering any-length MAD, MAD prevalence was 17.3%, 25.5%, 42.0% by TTE, TOE and CMR, respectively (p<0.05). The agreement on MAD identification was moderate between TTE and CMR (κ=0.54, 95% CI 0.49 to 0.59) and good between TOE and CMR (κ=0.79, 95% CI 0.74 to 0.84). Assuming CMR as reference and according to different cut-off values for MAD (≥2 mm, ≥4 mm, ≥6 mm), specificity (95% CI) of TTE and TOE was 99.6 (99.0 to 100.0)% and 98.7 (97.4 to 100.0)%; 99.3 (98.4 to 100.0)% and 97.6 (95.8 to 99.4)%; 97.8 (96.2 to 99.3)% and 93.2 (90.3 to 96.1)%, respectively; sensitivity (95% CI) was 43.1 (37.8 to 48.4)% and 74.5 (69.4 to 79.5)%; 54.0 (48.7 to 59.3)% and 88.9 (85.2 to 92.5)%; 88.0 (84.5 to 91.5)% and 100.0 (100.0 to 100.0)%, respectively. MAD length was 8.0 (7.0-10.0), 7.0 (5.0-8.0], 5.0 (4.0-7.0) mm, respectively by TTE, TOE and CMR. Agreement on MAD measurement was moderate between TTE and CMR (ρ=0.73) and strong between TOE and CMR (ρ=0.86). CONCLUSIONS: An integrated imaging approach could be necessary for a comprehensive assessment of patients with MVP and symptoms suggestive for arrhythmias. If echocardiography is fundamental for the anatomic and haemodynamic characterisation of the MV disease, CMR may better identify small length MAD as well as myocardial fibrosis.

Reliability of single breath hold three-dimensional cine kat-ARC for the assessment of biventricular dimensions and function.

PURPOSE: To assess the accuracy and reproducibility of 3D-cine k-adaptative-t-autocalibrating reconstruction for cartesian sampling (3D cine kat-ARC) for quantification of biventricular volumes, ejection fraction and LV mass in clinical practice. METHOD: 74 patients underwent cardiac magnetic resonance for clinical indications. In the whole population 3D cine kat-ARC and 2D cine bSSFP images were acquired on short axis view. Subsequently, the population was divided in three subgroups (dilated, hypetrophic, other phenotypes). Two experienced observers performed analysis of volumes, biventricular function and left ventricular mass in the overall population and subgroups using an off-line workstation. Statistical analysis was performed using Student's t-test, linear regression and Bland-Altman plot, correlation coefficient η2 and the intraclass correlation coefficient (ICC). A cut-off value of p < 0.05 was considered statistically significant. RESULTS: Biventricular volumes, function and left ventricular mass evaluated with 3D cine kat-ARC sequences did not show any significant difference compared to 2D bSSFP sequences in the overall population (p > 0.05). Bland-Altman analysis showed limited bias and narrow limits of the agreement for all measurements in overall population. Subgroup analysis showed a statistically significant difference (p = 0.04) for left ventricular ejection fraction (LVEF) in patients with a dilated phenotype; showing a minimum overestimation tendency for 3D cine kat ARC (2D cine bSSFP LVEF = 46.44 ± 15.83% vs 3D cine kat-ARC LVEF = 48.36 ± 16.50 %). CONCLUSIONS: 3D cine kat-ARC 3D sequences allow an accurate evaluation of biventricular volumes and function in a single breath hold.

Echocardiographic Assessment of the Tricuspid Annulus: The Effects of the Third Dimension and Measurement Methodology.

BACKGROUND: Evaluation of the tricuspid annulus is crucial for the decision making at the time of left heart surgery. Current recommendations for tricuspid valve repair are based on two-dimensional (2D) transthoracic echocardiography (TTE), despite the known underestimation compared with three-dimensional (3D) echocardiography. However, little is known about the differences in 3D tricuspid annular (TA) sizing using TTE versus transesophageal echocardiography (TEE). The aims of this study were to (1) compare 2D and 3D TA measurements performed with both TTE and TEE and (2) compare two 3D methods for TA measurements: multiplanar reconstruction (MPR) and dedicated software (DS) designed to take into account TA nonplanarity. METHODS: Seventy patients underwent 2D and 3D TTE and TEE. Two-dimensional images were used to measure TA diameter from apical four-chamber, right ventricular-focused (TTE), and midesophageal four-chamber (TEE) views. Three-dimensional full-volume data sets were analyzed using both MPR and DS, to obtain major and minor axes, perimeter, and area. Intertechnique agreement was assessed using Bland-Altman analysis. RESULTS: Measurements on 2D TTE and TEE, which were view dependent, underestimated TA major dimensions in all views compared with 3D values, irrespective of the 3D method. MPR and DS measurements were significantly different, with DS resulting in larger values for all parameters, irrespective of approach. No differences were found between 3D TTE and 3D TEE for both MPR and DS. CONCLUSIONS: Our findings highlight the need for methodology that respects the 3D geometry of the tricuspid annulus, including its nonplanarity, which cannot be accurately assessed from 2D images and is not equally taken into account by different 3D measurement methodologies. Accordingly, a 3D cutoff value for TA enlargement needs to be established and is likely to be larger than the guideline-recommended 2D-based 40-mm cutoff. Importantly, noninvasive 3D TTE can be used instead of 3D TEE because TA measurements are not different.

Comprehensive Assessment of Mitral Valve Geometry and Cardiac Remodeling With 3-Dimensional Echocardiography After Percutaneous Mitral Valve Repair.

MitraClip is a validated treatment for significant mitral regurgitation (MR) in high-risk patients. Aims of the study were to evaluate immediate changes in mitral valve (MV) geometry induced by MitraClip and correlations between baseline geometry and cardiac remodeling. Eighty patients who underwent MitraClip for primary (48%) or secondary (52%) MR were enrolled. Intraoperative transesophageal echocardiographic 3D images were acquired immediately before and after the procedure for MV annulus (MVA) morphology analysis. Transthoracic 3D echocardiography was performed preoperatively and at 6 months follow-up (6MFU). Patients were classified on the basis of MR reduction (ΔMR) at 6MFU as Optimal (ΔMR ≥ 2) or Suboptimal (ΔMR < 2). An optimal result was reached in 60 (75%) patients, whereas 20 subjects showed a ΔMR< 2 at 6MFU. The Optimal showed significantly smaller baseline MVA (antero-posterior diameter 4.05 ± 0.59 vs 4.43 ± 0.68 cm; anterolateral-posteromedial diameter 4.38 ± 0.56 vs 4.70 ± 0.73 cm; MVA circumference 14.1 ± 1.7 vs 15.1 ± 2.3 cm; and 3D area 14.8 ± 3.9 vs 17.4 ± 5.3 cm2), lower sphericity index and nonplanar angle compared with Suboptimal. A value of antero-posterior diameter ≥4.44cm was identified (receiver-operating characteristic curve) as a possible cut-off for preoperative identification of Suboptimal patients. Postoperatively, MitraClip induced reduction of MVA flattening (nonplanar angle), sphericity index, and size (as expressed by antero-posterior diameter, MVA circumference and area). At 6MFU, the Optimal showed significant decrease in left ventricular volumes and pulmonary artery systolic pressure. In conclusion, MitraClip induces remarkable changes in MVA geometry and favorable left ventricular remodeling is detected in patients with optimal mid-term outcome; a preprocedural antero-posterior diameter <4.44cm seems to be a potential predictor of mid-term optimal result.

Technological Advancements in Echocardiographic Assessment of Thoracic Aortic Dilatation: Head to Head Comparison Among Multidetector Computed Tomography, 2-Dimensional, and 3-Dimensional Echocardiography Measurements.

PURPOSE: The aim of this study was to evaluate the feasibility and accuracy of 2-dimensional (2D) and 3-dimensional (3D) transthoracic echocardiography (2DTTE, 3DTTE) versus multidetector computed tomography (MDCT) in patients with ascending aortic (AA) dilation. MATERIALS AND METHODS: Fifty consecutive patients with AA dilation were evaluated by 2DTTE, X-plane (XP) 3DTTE, and MDCT. Aorta diameters were measured at aortic annulus, aortic root (SIN), sinotubular junction, AA, aortic arch before the prebrachiocephalic artery (PRE), and before left subclavian artery (INTRA). Leading edge-to-leading edge (L-L) and inner-to-inner (I-I) measurements were compared with MDCT data. RESULTS: Feasibility, quality of imaging, and accuracy was high with all echocardiographic methods. Specifically for MDCT maximum SIN diameter, the best correlation and agreement was obtained using XP maximum diameter at 3DTTE (MDCT: 44.8±7.4 mm vs. XP: 44.4±7.4 mm; r=0.975; bias=-0.4 mm). The same was true for AA maximum diameter at MDCT (MDCT: 46.6±8.1 mm vs. XP: 47.5±8.1 mm; r=0.991; bias=0.1 mm). For aortic arch the best correlation and agreement with MDCT were as follows: 2DTTE L-L diameter for arch PRE (MDCT: 37.9±5.3 mm vs. TTE: 36.6±4.5 mm; r=0.927; bias=-0.9 mm) and MDCT minimum diameter with XP minimum diameter for arch INTRA (MDCT: 28.2±5.0 mm vs. TTE 28.8±4.7 mm; r=0.939; bias=-0.3 mm). CONCLUSION: In patients with aortic dilatation or aneurysm, new techniques (mainly 2D-3D probes allowing XP views) facilitate accuracy of aortic measurements at different sites of the vessel and allow standardization of analysis to better compare with MDCT.

Recomendações para Avaliação por Imagens das Próteses Valvares Cardíacas / Recommendations for the Imaging Assessment of Prosthetic Heart Valves

Disfunção de prótese valvar cardíaca (PVC) é rara, porém é uma potencial ameaça à vida. Estabelecer o exato mecanismo da disfunção da PVC é desafiador, no entanto é essencial para determinar a estratégia terapêutica apropriada. Na prática clinica, uma abordagem abrangente que integra vários parâmetros de morfologia e função avaliados pelo eco transtorácico 2D/3D e transesofágico são fundamentais para detectar e quantificar a disfunção da PVC. A cinefluoroscopia, a tomografia computadorizada com multidectetores, a ressonância magnética cardíaca, e em menor escala, a imagem nuclear, são ferramentas complementares para o diagnóstico e abordagem das complicações das PVC. Este documento apresenta recomendações para o uso de imagem em multimodalidade para avaliação das PVCs

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.

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.

Recommendations for the imaging assessment of prosthetic heart valves: a report from the European Association of Cardiovascular Imaging endorsed by the Chinese Society of Echocardiography, the Inter-American Society of Echocardiography, and the Brazilian Department of Cardiovascular Imaging.

Prosthetic heart valve (PHV) dysfunction is rare but potentially life-threatening. Although often challenging, establishing the exact cause of PHV dysfunction is essential to determine the appropriate treatment strategy. In clinical practice, a comprehensive approach that integrates several parameters of valve morphology and function assessed with 2D/3D transthoracic and transoesophageal echocardiography is a key to appropriately detect and quantitate PHV dysfunction. Cinefluoroscopy, multidetector computed tomography, cardiac magnetic resonance imaging, and to a lesser extent, nuclear imaging are complementary tools for the diagnosis and management of PHV complications. The present document provides recommendations for the use of multimodality imaging in the assessment of PHVs.

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.

Three-dimensional dynamic assessment of tricuspid and mitral annuli using cardiovascular magnetic resonance.

AIMS: To explore the potentiality of cardiovascular magnetic resonance (CMR) in the quantitative evaluation of mitral valve annulus (MVA) and tricuspid valve annulus (TVA) morphology and dynamics. METHODS AND RESULTS: CMR was performed in 13 normal subjects and 9 patients with mitral (n = 7) or tricuspid regurgitation (n = 2), acquiring cine-images in 18 radial long-axis planes passing through the middle of MVA or TVA. A novel algorithm was used to obtain dynamic three-dimensional (3D) reconstruction of MVA and TVA. Analysis was feasible in all cases, allowing accurate 3D annular reconstruction and tracking. The 3D area increased from systole [MVA, median = 10.0 cm(2) (first quartile = 8.6, third quartile = 11.4); TVA, 11.2 cm(2) (8.8-13.2)] to diastole [MVA, 10.6 cm(2) (9.4, 11.7); TVA, 11.9 cm(2) (9.2-13.5)], with TVA larger than MVA. While the longest diameter showed similar systolic and diastolic values, the shortest diameter elongated from systole [MVA, 30 mm (29-33); TVA, 33 mm (31-36)] to diastole [MVA, 31 mm (29-32); TVA, 36 mm (33-39)]. Also, TVA became more circular than MVA. TVA showed lower peak systolic excursion in the septal [15.9 mm (13.0-18.5)] and anterior regions [17.9 mm (12.2-20.7)] compared with the posterior [21.9 mm (18.6-24.0)] segment. Values in MVA were smaller than in TVA, slightly higher in anterior [11.2 mm (9.5-13.0)] than in posterior [12.4 mm (10.2-14.6)] segments. Valvular regurgitation was associated with enlarged, flattened, and more circular annuli. CONCLUSION: The applied method was feasible and accurate in normal and regurgitant valves, and may potentially have an impact on diagnosis, improvement of surgical techniques and design of annular prostheses.

Pre-operative CT coronary angiography in patients with mitral valve prolapse referred for surgical repair: comparison of accuracy, radiation dose and cost versus invasive coronary angiography.

BACKGROUND: The aims of this study are to evaluate the accuracy of low dose multidetector computed tomography coronary angiography (MDCT) versus invasive coronary angiography (ICA) in ruling out CAD in patients with mitral valve prolapse and severe mitral regurgitation (MVP) before cardiac surgery and to compare the overall effective radiation dose (ED) and cost of a diagnostic approach in which conventional ICA should be performed only in patients with significant CAD as detected by MDCT. METHODS: Eighty patients with MVP and without history of CAD were randomized to MDCT (Group 1) or ICA (Group 2) to rule out CAD before surgery. However, ICA was also performed as gold standard reference in Group 1 to test the diagnostic accuracy of MDCT. A diagnostic work-up A in whom all patients underwent low-dose MDCT as initial diagnostic test and those with positive findings were referred for ICA was compared with work-up B in which all patients were referred for ICA according to the standard of care in terms of ED and cost. RESULTS: The two groups were homogeneous in terms of gender, age and body mass index. The overall feasibility and accuracy in a patient-based model were 99% and 93%, respectively. The overall ED and costs were significantly lower in diagnostic work-up A compared to diagnostic work-up B. CONCLUSIONS: The accuracy of low dose MDCT for ruling out the presence of significant CAD in patients undergoing elective valve surgery for mitral valve prolapse is excellent with a reduction of overall radiation dose exposure and costs.

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.

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.

Diagnostic performance of two types of low radiation exposure protocol for prospective ECG-triggering multidetector computed tomography angiography in assessment of coronary artery bypass graft.

BACKGROUND: Multidetector computed tomography (MDCT) is useful in evaluation of coronary artery bypass graft (CABG). However, radiation exposure is a reason for concern. We compared diagnostic performance and effective dose of a new dedicated post-processing reconstruction algorithm with BMI-adapted scanning protocol (MDCT-XTe) vs. standard prospective ECG-triggering protocol (MDCT-XT) and retrospective ECG-triggering (MDCT-Helical), compared to invasive coronary angiography (ICA), in the assessment of grafts and nongrafted or distal runoff coronary arteries. METHODS: One hundred and nineteen patients with 277 grafts were randomized to Group 1 based on BMI-adapted scanning protocol with prospective ECG-triggering (40 patients), Group 2 with prospective ECG-triggering (39 patients) and Group 3 (40 patients) with retrospective ECG-triggering. Data were acquired using 64-slice MDCT. RESULTS: MDCT correctly assessed the patency of all CABG in 3 groups. After comparison with ICA, MDCT was able to correctly detect the occlusion or stenosis of CABG in all groups, with the exception of one case of Group 3. In Group 3 sensitivity, specificity, positive predictive value, negative predictive value and accuracy of CABG evaluation were 100%, 98.4%, 96.7%, 100% and 98.9%, respectively. In Groups 1 and 2 the diagnostic accuracy of CABG evaluation was 100%. Effective radiation dose was 3.5±1.4mSv in Group 1 vs. 7.4±2.6mSv in Group 2 vs. 27.8±9.4mSv in Group 3. CONCLUSIONS: Our results indicated that MDCT-XTe and MDCT-XT have a diagnostic performance in the evaluation of CABG similar to MDCT-Helical, with a significant reduction of radiation exposure, specially for MDCT-XTe.

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.

Multidetector computed tomography coronary angiography for the assessment of coronary in-stent restenosis.

The investigators conducted a review to evaluate the diagnostic performance of multidetector computed tomography (MDCT) for coronary stent evaluation. The prespecified inclusion criteria selected prospective or retrospective human studies published in English. Studies that did not report raw numbers of diagnostic accuracy for the detection of in-stent restenosis were excluded. The data from 24 studies are reported, 6 performed with old-generation scanners (4-, 16-, and 40-slice MDCT) and 18 performed with 64-slice MDCT or dual-source MDCT. With old-generation MDCT, up to 18% of coronary stents were missed, the rate of nonevaluable stents ranged from 2.6% to 23.5%, and the overall feasibility and diagnostic accuracy were 90.4% and 90%, respectively. With 64-slice MDCT, no stent was missed, and the overall feasibility and diagnostic accuracy were 90.4% and 91.9%, respectively. Advancements in MDCT and stent technologies may further reduce the number of nonassessable stents and improve diagnostic performance.