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.

Prodromal angina is associated with myocardial salvage in acute ST-segment elevation myocardial infarction.

AIMS: Previous studies have shown that prodromal angina (PA) occurs frequently in acute myocardial infarction (MI) patients. However, the potential benefits of PA on ischaemic myocardial damage remain unknown. METHODS AND RESULTS: One-hundred and fifty-four patients with acute ST-segment elevation MI successfully treated with primary percutaneous coronary intervention (PPCI) were prospectively evaluated for new-onset PA in the week preceding infarction and other factors known to influence myocardial salvage. Cardiovascular magnetic resonance was performed 8 ± 3 days after MI for the assessment of area-at-risk (AAR), MI size, myocardial haemorrhage (MH), microvascular obstruction (MO), and myocardial salvage index (MSI). Patients with PA (n = 60) compared with those without PA (n = 94) showed similar AAR but significantly smaller MI size leading to larger MSI (0.53 ± 0.27 vs. 0.32 ± 0.26, P < 0.001). Additionally, patients with PA had lower incidence of MH (18 vs. 33%) and MO (22 vs. 46%) than non-PA patients (both P < 0.05). At univariate analysis, higher MSI was associated with new-onset PA, lower myocardial oxygen consumption before PPCI, shorter time-to-PPCI, and higher post-procedural TIMI flow-grade. Neither collateral circulation nor medications administered before PPCI were associated to MSI. After correction for other covariates by multivariate analysis, new-onset PA remained significantly associated with MSI (ß-value: 0.352, P < 0.001). CONCLUSION: In acute MI patients, new-onset PA is associated with higher MSI independent of others factors known to influence jeopardized myocardium, as well as with less microvascular damage.

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.

Bypass graft and native postanastomotic coronary artery patency: assessment with computed tomography.

BACKGROUND: Multidetector computed tomography has been shown to be useful in the evaluation of coronary artery bypass grafts in previous studies. We studied the accuracy of multidetector computed tomography in the detection of patency and significant stenosis of both grafts and native postanastomotic coronary arteries. METHODS: Ninety-six patients with 216 grafts (98 left mammary artery, 8 right mammary artery, 8 radial artery, and 102 venous grafts) were investigated by 16-slice computed tomography. Native postanastomotic coronary arteries were also evaluated. Patients unable to maintain a breath hold of 40 s were excluded. Computed tomography data were compared with the results of conventional angiography. RESULTS: On a segment-based model, the overall feasibility of computed tomography was 98.1% (212 of 216 grafts) for bypass grafts and 93.1% (201 of 216 segments) for postanastomotic coronary arteries. The leading cause of unfeasibility for postanastomotic coronary arteries was the small diameter of the examined vessel (<1.5 mm). Computed tomography correctly diagnosed all the 25 occluded grafts. Of the 33 significant stenoses of grafts, computed tomography correctly diagnosed 31. Sensitivity, specificity, positive predictive value, and negative predictive value were 100%, 98.5%, 96.5%, and 100%, respectively, for bypass graft; and 100%, 97.7%, 85%, and 100%, respectively, for coronary arteries. On a patient-based model, the feasibility, sensitivity, specificity, positive predictive value, and negative predictive value were 89.4% (86 of 96 patients), 100%, 93%, 86.4%, and 100%, respectively. CONCLUSIONS: Multidetector computed tomography allows a very accurate assessment of arterial and venous conduits and of postanastomotic native coronary arteries in patients with previous bypass graft. Despite high feasibility (93.1%), limitations of the method were breath-hold duration (35 to 40 s) and postanastomotic assessment of small vessels (which, however, precluded the analysis in only 4.6% of cases).