Age-and Gender-Specific Differences in the Prognostic Value of CT Coronary Angiography

OBJECTIVES: To evaluate the potential age- and gender-specific differences in the incidence and prognostic value of coronary artery disease (CAD) in patients undergoing CT coronary angiography (CTA).

METHODS: In this multicentre prospective registry study, 2432 patients (mean age 57±12, 56% male) underwent CTA for suspected CAD. Patients were stratified into four groups according to age <60 or ≥60 years and, male or female gender.Main outcome measuresA composite end point of cardiac death and non-fatal myocardial infarction.

RESULTS: CTA results were normal in 991 (41%) patients, showed non-significant CAD in 761 (31%) patients and significant CAD in the remaining 680 (28%) patients. During follow-up (median 819 days, 25-75th centile 482-1142) a cardiovascular event occurred in 59 (2.4%) patients. The annualised event rate was 1.1% in the total population (men=1.3% and women=0.9%). In patients aged <60 years, the annualised event rate of male and female patients was 0.6% and 0.5%, respectively. Among patients aged ≥60 years the annualised event rate was 1.9% in male and 1.1% in female patients. Observations on CTA predicted events in male patients, both age <60 and ≥60 years and in female patients age ≥60 years (log-rank test in all groups, p<0.01). However, CTA provided limited prognostic value in female patients aged <60 years (log-rank test, p=0.45).

CONCLUSIONS: After age and gender stratification, CTA findings were shown to be of limited predictive value in female patients aged <60 years as compared with male patients at any age and female patients aged ≥60 years.

PMID: 21917657

CT for Evaluation of Myocardial Cell Therapy in Heart Failure A Comparison With CMR Imaging

OBJECTIVES: The aim of this study was to use multidetector computed tomography (MDCT) to assess therapeutic effects of myocardial regenerative cell therapies. Cell transplantation is being widely investigated as a potential therapy in heart failure. Noninvasive imaging techniques are frequently used to investigate therapeutic effects of cell therapies in the preclinical and clinical settings. Previous studies have shown that cardiac MDCT can accurately quantify myocardial scar tissue and determine left ventricular (LV) volumes and ejection fraction (LVEF).

METHODS: Twenty-two minipigs were randomized to intramyocardial injection of phosphate-buffered saline (placebo, n = 9) or 200 million mesenchymal stem cells (MSC, n = 13) 12 weeks after myocardial infarction (MI). Cardiac magnetic resonance and MDCT acquisitions were performed before randomization (12 weeks after MI induction) and at the study endpoint 24 weeks after MI induction. None of the animals received medication to control the intrinsic heart rate during first-pass acquisitions for assessment of LV volumes and LVEF. Delayed-enhancement MDCT imaging was performed 10 min after contrast delivery. Two blinded observers analyzed MDCT acquisitions.

RESULTS: MDCT demonstrated that MSC therapy resulted in a reduction of infarct size from 14.3 ± 1.2% to 10.3 ± 1.5% of LV mass (p = 0.005), whereas infarct size increased in nontreated animals (from 13.8 ± 1.3% to 16.5 ± 1.5%; p = 0.02) (placebo vs. MSC; p = 0.003). Both observers had excellent agreement for infarct size (r = 0.96; p < 0.001). LVEF increased from 32.6 ± 2.2% to 36.9 ± 2.7% in MSC-treated animals (p = 0.03) and decreased in placebo animals (from 33.3 ± 1.4% to 29.1 ± 1.5%; p = 0.01; at week 24: placebo vs. MSC; p = 0.02). Infarct size, end-diastolic LV volume, and LVEF assessed by MDCT compared favorably with those assessed by cardiac magnetic resonance acquisitions (r = 0.70, r = 0.82, and r = 0.902, respectively; p < 0.001).

CONCLUSIONS: This study demonstrated that cardiac MDCT can be used to evaluate infarct size, LV volumes, and LVEF after intramyocardial-delivered MSC therapy. These findings support the use of cardiac MDCT in preclinical and clinical studies for novel myocardial therapies.

PMID: 22172785

Survival After Open Versus Endovascular Thoracic Aortic Aneurysm Repair in an Observational Study of the Medicare Population

OBJECTIVES: The goal of this study was to describe short- and long-term survival of patients with descending thoracic aortic aneurysms (TAAs) after open and endovascular repair (TEVAR).

METHODS: Using Medicare claims from 1998 to 2007, we analyzed patients who underwent repair of intact and ruptured TAA, identified from a combination of procedural and diagnostic International Classification of Disease, ninth revision, codes. Our main outcome measure was mortality, defined as perioperative mortality (death occurring before hospital discharge or within 30 days), and 5-year survival, from life-table analysis. We examined outcomes across repair type (open repair or TEVAR) in crude, adjusted (for age, sex, race, procedure year, and Charlson comorbidity score), and propensity-matched cohorts.

RESULTS: Overall, we studied 12 573 Medicare patients who underwent open repair and 2732 patients who underwent TEVAR. Perioperative mortality was lower in patients undergoing TEVAR compared with open repair for both intact (6.1% versus 7.1%; P=0.07) and ruptured (28% versus 46%; P<0.0001) TAA. However, patients with intact TAA selected for TEVAR had significantly worse survival than open patients at 1 year (87% for open, 82% for TEVAR; P=0.001) and 5 years (72% for open; 62% for TEVAR; P=0.001). Furthermore, in adjusted and propensity-matched cohorts, patients selected for TEVAR had worse 5-year survival than patients selected for open repair.

CONCLUSIONS: Although perioperative mortality is lower with TEVAR, Medicare patients selected for TEVAR have worse long-term survival than patients selected for open repair. The results of this observational study suggest that higher-risk patients are being offered TEVAR and that some do not benefit on the basis of long-term survival. Future work is needed to identify TEVAR candidates unlikely to benefit from repair.

PMID: 22104552

Image Quality and Radiation Exposure Using Different Low-Dose Scan Protocols in Dual-Source CT Coronary Angiography: Randomized Study

PMID: 21969666

Percutaneous Transvenous Melody Valve-in-Ring Procedure for Mitral Valve Replacement

OBJECTIVES: The purpose of this study was to demonstrate the feasibility of percutaneous transvenous mitral valve-in-ring (VIR) implantation using the Melody valve in an ovine model. The recurrence of mitral regurgitation following surgical mitral valve (MV) repair in both adult and pediatric patients remains a significant clinical problem. Mitral annuloplasty rings are commonly used in MV repair procedures and may serve as secure landing zones for percutaneous valves.

METHODS: Five sheep underwent surgical MV annuloplasty (24 mm, n = 2; 26 mm, n = 2; 28 mm, n = 1). Animals underwent cardiac catheterization with VIR implantation via a transfemoral venous, transatrial septal approach 1 week following surgery. Hemodynamic, angiographic, and echocardiographic data were recorded before and after VIR.

RESULTS: VIR was technically successful and required <1 h of procedure time in all animals. Fluoroscopy demonstrated securely positioned Melody valves within the annuloplasty ring in all animals. Angiography revealed no significant MV regurgitation in 4 and moderate central MV regurgitation in the animal with the 28-mm annuloplasty. All animals demonstrated vigorous left ventricular function, no outflow tract obstruction, and no aortic valve insufficiency.

CONCLUSIONS: This study demonstrated the feasibility of a purely percutaneous approach to MV replacement in patients with preexisting annuloplasty rings. This novel approach may be of particular benefit to patients with failed repair of ischemic mitral regurgitation and in pediatric patients with complex structural heart disease.

PMID: 22133846

Post-Mortem Imaging as an Alternative to Autopsy in the Diagnosis of Adult Deaths: A Validation Study

OBJECTIVES: Public objection to autopsy has led to a search for minimally invasive alternatives. Imaging has potential, but its accuracy is unknown. We aimed to identify the accuracy of post-mortem CT and MRI compared with full autopsy in a large series of adult deaths.

METHODS: This study was undertaken at two UK centres in Manchester and Oxford between April, 2006, and November, 2008. We used whole-body CT and MRI followed by full autopsy to investigate a series of adult deaths that were reported to the coroner. CT and MRI scans were reported independently, each by two radiologists who were masked to the autopsy findings. All four radiologists then produced a consensus report based on both techniques, recorded their confidence in cause of death, and identified whether autopsy was needed.

RESULTS: We assessed 182 unselected cases. The major discrepancy rate between cause of death identified by radiology and autopsy was 32% (95% CI 26-40) for CT, 43% (36-50) for MRI, and 30% (24-37) for the consensus radiology report; 10% (3-17) lower for CT than for MRI. Radiologists indicated that autopsy was not needed in 62 (34%; 95% CI 28-41) of 182 cases for CT reports, 76 (42%; 35-49) of 182 cases for MRI reports, and 88 (48%; 41-56) of 182 cases for consensus reports. Of these cases, the major discrepancy rate compared with autopsy was 16% (95% CI 9-27), 21% (13-32), and 16% (10-25), respectively, which is significantly lower (p<0·0001) than for cases with no definite cause of death. The most common imaging errors in identification of cause of death were ischaemic heart disease (n=27), pulmonary embolism (11), pneumonia (13), and intra-abdominal lesions (16).

CONCLUSIONS: We found that, compared with traditional autopsy, CT was a more accurate imaging technique than MRI for providing a cause of death. The error rate when radiologists provided a confident cause of death was similar to that for clinical death certificates, and could therefore be acceptable for medicolegal purposes. However, common causes of sudden death are frequently missed on CT and MRI, and, unless these weaknesses are addressed, systematic errors in mortality statistics would result if imaging were to replace conventional autopsy.

PMID: 22112684

Prevalence and Severity of Coronary Artery Disease and Adverse Events Among Symptomatic Patients With Coronary Artery Calcification Scores of Zero Undergoing Coronary Computed Tomography Angiography: Results From the CONFIRM (Coronary CT Angiography Evaluation for Clinical Outcomes: An International Multicenter) Registry

OBJECTIVES: The purpose of this study was to describe the prevalence and severity of coronary artery disease (CAD) in relation to prognosis in symptomatic patients without coronary artery calcification (CAC) undergoing coronary computed tomography angiography (CCTA). The frequency and clinical relevance of CAD in patients without CAC are unclear.

METHODS: We identified 10,037 symptomatic patients without CAD who underwent concomitant CCTA and CAC scoring. CAD was assessed as

RESULTS: Mean age was 57 years, 56% were men, and 51% had a CAC score of 0. Among patients with a CAC score of 0, 84% had no CAD, 13% had nonobstructive stenosis, and 3.5% had ≥50% stenosis (1.4% had ≥70% stenosis) on CCTA. A CAC score >0 had a sensitivity, specificity, and negative and positive predictive values for stenosis ≥50% of 89%, 59%, 96%, and 29%, respectively. During a median of 2.1 years, there was no difference in mortality among patients with a CAC score of 0 irrespective of obstructive CAD. Among 8,907 patients with follow-up for the composite endpoint, 3.9% with a CAC score of 0 and ≥50% stenosis experienced an event (hazard ratio: 5.7; 95% confidence interval: 2.5 to 13.1; p < 0.001) compared with 0.8% of patients with a CAC score of 0 and no obstructive CAD. Receiver-operator characteristic curve analysis demonstrated that the CAC score did not add incremental prognostic information compared with CAD extent on CCTA for the composite endpoint (CCTA area under the curve = 0.825; CAC + CCTA area under the curve = 0.826; p = 0.84).

CONCLUSIONS: In symptomatic patients with a CAC score of 0, obstructive CAD is possible and is associated with increased cardiovascular events. CAC scoring did not add incremental prognostic information to CCTA.

PMID:

Intracoronary Transluminal Attenuation Gradient in Coronary CT Angiography for Determining Coronary Artery Stenosis

OBJECTIVES: Coronary computed tomography angiography (CTA) assessment of calcified or complex coronary lesions is frequently challenging. Transluminal attenuation gradient (TAG), defined as the linear regression coefficient between luminal attenuation and axial distance, has a potential to evaluate the degree of coronary stenosis.

METHODS: We examined the value of TAG in determining the stenosis severity on 64-slice coronary CTA. The value of TAG of 370 major coronary arteries was measured from 7,263 intervals of 5-mm length.

RESULTS: Compared with coronary CTA and invasive coronary angiography, TAG decreased consistently and significantly with maximum stenosis severity on a per-vessel basis, from -1.91 ± 4.25 Hounsfield units/10 mm for diameter stenosis of 0% to 49% to -13.37 ± 9.81 Hounsfield units/10 mm for diameter stenosis of 100% (p < 0.0001). Adding TAG to the interpretation of coronary CTA improved diagnostic accuracy (p = 0.001), especially in vessels with calcified lesions (N = 127; net reclassification improvement 0.095; p = 0.046).

CONCLUSIONS: TAG appears to be able to contribute to improved classification of coronary artery stenosis severity in coronary CTA, especially in severely calcified lesions.

PMID: 22093264

Association of Coronary CT Angiography or Stress Testing With Subsequent Utilization and Spending Among Medicare Beneficiaries

OBJECTIVES: Coronary computed tomography angiography (CCTA) is a new noninvasive diagnostic test for coronary artery disease (CAD), but its association with subsequent clinical management has not been established. The objective here is to compare utilization and spending associated with functional (stress testing) and anatomical (CCTA) noninvasive cardiac testing in a Medicare population.

METHODS: Retrospective, observational cohort study using claims data from a 20% random sample of 2005-2008 Medicare fee-for-service beneficiaries 66 years or older with no claims for CAD in the preceding year, who received nonemergent, noninvasive testing for CAD (n = 282 830).The main outcome measure was cardiac catheterization, coronary revascularization, acute myocardial infarction, all-cause mortality, and total and CAD-related Medicare spending over 180 days of follow-up.

RESULTS: Compared with stress myocardial perfusion scintigraphy (MPS), CCTA was associated with an increased likelihood of subsequent cardiac catheterization (22.9% vs 12.1%; adjusted odds ratio [AOR], 2.19 [95% CI, 2.08 to 2.32]; P < .001), percutaneous coronary intervention (7.8% vs 3.4%; AOR, 2.49 [2.28 to 2.72]; P < .001), and coronary artery bypass graft surgery (3.7% vs 1.3%; AOR, 3.00 [2.63 to 3.41]; P < .001). CCTA was also associated with higher total health care spending ($4200 [$3193 to $5267]; P < .001), which was almost entirely attributable to payments for any claims for CAD ($4007 [$3256 to $4835]; P < .001). Compared with MPS, there was lower associated spending with stress echocardiography (−$4981 [−$4991 to −$4969]; P < .001) and exercise electrocardiography (−$7449 [−$7452 to −$7444]; P < .001). At 180 days, CCTA was associated with a similar likelihood of all-cause mortality (1.05% vs 1.28%; AOR, 1.11 [0.88 to 1.38]; P = .32) and a slightly lower likelihood of hospitalization for acute myocardial infarction (0.19% vs 0.43%; AOR, 0.60 [0.37 to 0.98]; P = .04).

CONCLUSIONS: Medicare beneficiaries who underwent CCTA in a nonacute setting were more likely to undergo subsequent invasive cardiac procedures and have higher CAD-related spending than patients who underwent stress testing.

PMID:

Diagnostic Accuracy of First Generation Dual-Source Computed Tomography in the Assessment of Coronary Artery Disease: A Meta-Analysis from 24 Studies

OBJECTIVES: The objective of this study is to evaluate the diagnostic accuracy of the first generation dual-source computed tomography (DSCT) in the diagnosis of coronary artery disease (CAD).

METHODS: We selected articles from four databases (Pubmed, Embase, the Cochrane central register of controlled trials (CENTRAL) and Chinese biomedical literature database. The strict study selection was made, and two reviewers independently extracted data back-to-back from included studies. Meta-Disc version 1.4 was used to obtain the pooled results.

RESULTS: 24 studies were included in meta-analysis. A cut off point of ≥50% stenosis was used in all the studies to define significant coronary artery stenosis. In patient-based analysis (n = 801), pooled sensitivity was 0.980 [95% confidence interval (CI):0.970-0.990], specificity 0.870 (95% CI: 0.830-0.900), median positive predictive value (PPV) across studies 0.876 (range from 0.741 to 0.943) and negative predictive value (NPV) 0.964 (range from 0.900 to 1.000). In vessel-based analysis (n = 3,620) DSCT pooled sensitivity was 0.957 (95% CI: 0.943-0.969), specificity 0.930 (95% CI: 0.910-0.940), median PPV across studies 0.838 (range from 0.534 to 0.964) and NPV 0.973 (range from 0.885 to 0.996). In segment-based analysis (n = 6,177) DSCT pooled sensitivity was 0.915 (95% CI: 0.901-0.928), specificity 0.959 (95% CI: 0.956-0.963), median PPV 0.782 (range from 0.320 to 0.927) and NPV 0.985 (range from 0.929 to 0.999). In subgroups analysis, pooled sensitivity and specificity in segment based analysis were 93.1 and 92.3% when heart rate (HR) is beyond 70 bpm; when HR was below 70 bpm, the sensitivity was similar (93%), but specificity increased a little from 92.3 to 94%. When analysed based on segment with a cut-off calcium score of 400, the sensitivity was slightly higher in the subgroup with a score over 400 than in the subgroup with a score below 400 (94 vs. 91%), while the specificity was much lower in the subgroup with the high calcium score than the subgroup with the low calcium score (85 vs. 96%). For subgroups with heart rate beyond and below 65 bpm in patient-based analysis, sensitivities were 0.95 (95% CI: 0.86-0.99) and 0.98 (95% CI 0.91-1.00), respectively, while the specificities were 0.88 (95% CI 0.81-0.94) and 0.85 (95% CI 0.77-0.91), respectively. The area under the receiver operating characteristic curve (AUC) in the two subgroups were 0.9608 and 0.9786, respectively.

CONCLUSIONS: DSCT is highly sensitive for patient-based analysis of CAD and has high specificity and NPV for segment-based analysis of CAD. First generation DSCT may have a role in the evaluation of patients with chest pain as a simple non-invasive examination because of its ability to diagnose or exclude significant CAD.

PMID:

Multimodality Imaging in Transcatheter Aortic Valve Implantation and Post-Procedural Aortic Regurgitation: Comparison Among Cardiovascular Magnetic Resonance, Cardiac Computed Tomography, and Echocardiography

OBJECTIVES: The purpose of this study was to determine imaging predictors of aortic regurgitation (AR) after transcatheter aortic valve implantation (TAVI) and the agreement and reproducibility of cardiovascular magnetic resonance (CMR), cardiac computed tomography (CCT), and transthoracic echocardiography (TTE) in aortic root assessment. The optimal imaging strategy for planning TAVI is unclear with a paucity of comparative multimodality imaging data. The association between aortic root morphology and outcomes after TAVI also remains incompletely understood.

METHODS: A total of 202 consecutive patients assessed by CMR, CCT, and TTE for TAVI were studied. Agreement and variability among and within imaging modalities was assessed by Bland-Altman analysis. Postoperative AR was assessed by TTE.

RESULTS: Of the 202 patients undergoing TAVI assessment with both CMR and TTE, 133 also underwent CCT. Close agreement was observed between CMR and CCT in dimensions of the aortic annulus (bias, –0.4 mm; 95% limits of agreement: –5.7 to 5.0 mm), and similarly for sinus of Valsalva, sinotubular junction, and ascending aortic measures. Agreement between TTE-derived measures and either CMR or CCT was less precise. Intraobserver and interobserver variability were lowest with CMR. The presence and severity of AR after TAVI were associated with larger aortic valve annulus measurements by both CMR (p = 0.03) and CCT (p = 0.04) but not TTE-derived measures (p = 0.10). Neither CCT nor CMR measures of annulus eccentricity, however, predicted AR after TAVI (p = 0.33 and p = 0.78, respectively).

CONCLUSIONS: In patients undergoing imaging assessment for TAVI, the presence and severity of AR after TAVI were associated with larger aortic annulus measurements by both CMR and CCT, but not TTE. Both CMR and CCT provide highly reproducible information in the assessment of patients undergoing TAVI.

PMID:

Radiography of Cardiac Conduction Devices: A Comprehensive Review

Radiology plays a crucial role in initial assessment and follow-up of cardiac conduction devices (CCDs). At least 1 million patients in the United States have permanent CCDs, which comprise pacemakers and implantable cardioverter-defibrillators. Chest radiography is unique because it is the only imaging modality that allows evaluation of the physical integrity of CCD leads. As a result, a basic knowledge of the normal and abnormal radiographic appearances of these devices and their various components is important. Radiologists should have a working knowledge of CCD anatomy as well as appropriate positioning and appearance of CCD leads and generators. Acute complications of CCD implantation include dysrhythmia, pneumothorax, perforation of the heart muscle or a vein, heart valve damage, lead damage, inadequate seating of the terminal connector pin, and presence of an air pocket. Chronic complications include twiddler syndrome, lead fracture, damage to the lead insulation, and lead displacement. Radiologists play an important role in management of patients with CCDs by providing vital information about the device, starting immediately after implantation and continuing throughout its duration in the patient. To fulfill this role, radiologists must have a firm understanding of CCDs and their evolving technology.

PMID: 21997988

Diagnosis of Ischemia-Causing Coronary Stenoses by Noninvasive Fractional Flow Reserve Computed From Coronary Computed Tomographic Angiograms

OBJECTIVES: The aim of this study was to determine the diagnostic performance of a new method for quantifying fractional flow reserve (FFR) with computational fluid dynamics (CFD) applied to coronary computed tomography angiography (CCTA) data in patients with suspected or known coronary artery disease (CAD). Measurement of FFR during invasive coronary angiography is the gold standard for identifying coronary artery lesions that cause ischemia and improves clinical decision-making for revascularization. Computation of FFR from CCTA data (FFRCT) provides a noninvasive method for identifying ischemia-causing stenosis; however, the diagnostic performance of this new method is unknown.

METHODS: Computation of FFR from CCTA data was performed on 159 vessels in 103 patients undergoing CCTA, invasive coronary angiography, and FFR. Independent core laboratories determined FFRCT and CAD stenosis severity by CCTA. Ischemia was defined by an FFRCT and FFR 0.80, and anatomically obstructive CAD was defined as a CCTA with stenosis 50%. Diagnostic performance of FFRCT and CCTA stenosis was assessed with invasive FFR as the reference standard.

RESULTS: Fifty-six percent of patients had 1 vessel with FFR 0.80. On a per-vessel basis, the accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were 84.3%, 87.9%, 82.2%, 73.9%, 92.2%, respectively, for FFRCT and were 58.5%, 91.4%, 39.6%, 46.5%, 88.9%, respectively, for CCTA stenosis. The area under the receiver-operator characteristics curve was 0.90 for FFRCT and 0.75 for CCTA (p = 0.001). The FFRCT and FFR were well correlated (r = 0.717, p < 0.001) with a slight underestimation by FFRCT (0.022 ± 0.116, p = 0.016).

CONCLUSIONS: Noninvasive FFR derived from CCTA is a novel method with high diagnostic performance for the detection and exclusion of coronary lesions that cause ischemia.

PMID:

Stable Angina Pectoris: Head-to-Head Comparison of Prognostic Value of Cardiac CT and Exercise Testing

OBJECTIVES: To determine and compare the prognostic value of cardiac computed tomographic (CT) angiography, coronary calcium scoring, and exercise electrocardiography (ECG) in patients with chest pain who are suspected of having coronary artery disease (CAD).

METHODS: This study complied with the Declaration of Helsinki, and the local ethics committee approved the study. Patients (n = 471) without known CAD underwent exercise ECG and dual-source CT at a rapid assessment outpatient chest pain clinic. Coronary calcification and the presence of 50% or greater coronary stenosis (in one or more vessels) were assessed with CT. Exercise ECG results were classified as normal, ischemic, or nondiagnostic. The primary outcome was a major adverse cardiac event (MACE), defined as cardiac death, nonfatal myocardial infarction, or unstable angina requiring hospitalization and revascularization beyond 6 months. Univariable and multivariable Cox regression analysis was used to determine the prognostic values, while clinical impact was assessed with the net reclassification improvement metric.

RESULTS: Follow-up was completed for 424 (90%) patients; the mean duration of follow-up was 2.6 years. A total of 44 MACEs occurred in 30 patients. Four of the MACEs were cardiac deaths and six were nonfatal myocardial infarctions. The presence of coronary calcification (hazard ratio [HR], 8.22 [95% confidence interval {CI}: 1.96, 34.51]), obstructive CAD (HR, 6.22 [95% CI: 2.77, 13.99]), and nondiagnostic stress test results (HR, 3.00 [95% CI: 1.26, 7.14]) were univariable predictors of MACEs. In the multivariable model, CT angiography findings (HR, 5.0 [95% CI: 1.7, 14.5]) and nondiagnostic exercise ECG results (HR, 2.9 [95% CI: 1.2, 7.0]) remained independent predictors of MACEs. CT angiography findings showed incremental value beyond clinical predictors and stress testing (global χ(2), 37.7 vs 13.7; P < .001), whereas coronary calcium scores did not have further incremental value (global χ(2), 38.2 vs 37.7; P = .40).

CONCLUSIONS: CT angiography findings are a strong predictor of future adverse events, showing incremental value over clinical predictors, stress testing, and coronary calcium scores.

PMID: 21873254

Single-Centre Prospective Comparison Between Contrast-Enhanced Ultrasound and Computed Tomography Angiography after EVAR

OBJECTIVES: To evaluate contrast-enhanced ultrasound (CEUS) as an effective alternative to CT-angiography (CTA) for endoleak detection and aneurismal sac diameter measurement in the follow-up after endovascular abdominal aortic aneurysm repair (EVAR).

METHODS:From January 2006 to December 2010, 395 patients underwent EVAR follow-up with both CTA and CEUS. The diameter of the aneurismal sac and the presence of endoleaks were evaluated in all the 395 paired examinations.

RESULTS: Bland-Altman plots showed a good agreement in aneurismal sac diameter evaluation between the two imaging modalities. The mean diameter was 54.93 mm (standard deviation (SD) ±12.57) with CEUS and 56.01 mm (SD ± 13.23) with CTA. The mean difference in aneurismal sac diameter was -1.08 mm ±

3.3543 (95% confidence interval (CI), -0.75 to -1.41), in favour of CTA. The number of observed agreement in endoleak detection was 359/395 (90.89%). The two modalities detected the same type I and type III endoleaks. McNemar’s χ(2) test confirmed that CTA and CEUS are equivalent in endoleak detection.

CONCLUSIONS: CEUS demonstrated to be as accurate as CTA in endoleak detection and abdominal aortic aneurysm diameter measurements during EVAR follow-up, without carrying the risks of radiation exposure or nephrotoxicity. Even if it cannot be proposed as the sole imaging modality during follow-up, our analysis suggests that it should have a major role.

PMID: 21962588