Prognostic Utility of Cardiovascular Magnetic Resonance-Based Phenotyping in Patients With Muscular Dystrophy.

Background The prognostic utility of cardiovascular magnetic resonance imaging, including strain analysis and tissue characterization, has not been comprehensively investigated in adult patients with muscular dystrophy. Methods and Results We prospectively enrolled 148 patients with dystrophinopathies (including heterozygotes), limb-girdle muscular dystrophy, and type 1 myotonic dystrophy (median age, 36.0 [interquartile range, 23.0-50.0] years; 51 [34.5%] women) over 7.7 years in addition to an age- and sex-matched healthy control cohort (n=50). Cardiovascular magnetic resonance markers, including 3-dimensional strain and fibrosis, were assessed for their respective association with major adverse cardiac events. Our results showed that markers of contractile performance were reduced across all muscular dystrophy groups. In particular, the dystrophinopathies cohort experienced reduced left ventricular (LV) ejection fraction and high burden of replacement fibrosis. Patients with type 1 myotonic dystrophy showed a 26.8% relative reduction in LV mass with corresponding reduction in chamber volumes. Eighty-two major adverse cardiac events occurred over a median follow-up of 5.2 years. Although LV ejection fraction was significantly associated with major adverse cardiac events (adjusted hazard ratio [aHR], 3.0 [95% CI, 1.4-6.4]) after adjusting for covariates, peak 3-dimensional strain amplitude demonstrated greater predictive value (minimum principal amplitude: aHR, 5.5 [95% CI, 2.5-11.9]; maximum principal amplitude: aHR, 3.3 [95% CI, 1.6-6.8]; circumferential amplitude: aHR, 3.4 [95% CI, 1.6-7.2]; longitudinal amplitude: aHR, 3.4 [95% CI, 1.7-6.9]; and radial strain amplitude: aHR, 3.0 [95% CI, 1.4-6.1]). Minimum principal strain yielded incremental prognostic value beyond LV ejection fraction for association with major adverse cardiac events (change in χ2=13.8; P<0.001). Conclusions Cardiac dysfunction is observed across all muscular dystrophy subtypes; however, the subtypes demonstrate distinct phenotypic profiles. Myocardial deformation analysis highlights unique markers of principal strain that improve risk assessment over other strain markers, LV ejection fraction, and late gadolinium enhancement in this vulnerable patient population.

TITAN Trial: A Randomized Controlled Trial of a Cardiac Rehabilitation Care Model in Breast Cancer.

Background: Cardiac rehabilitation (CR) modeled care is recommended for patients with breast cancer to mitigate risk of cardiotoxicity. However, the cardiovascular impact of CR-modeled interventions has not been studied. Objectives: The purpose of this study was to evaluate if a multidisciplinary model of CR reduces cardiotoxicity and improves cardiovascular risk in patients undergoing breast cancer treatment. Methods: We randomly assigned patients with stage I to III breast cancer scheduled to receive anthracycline and/or trastuzumab-based chemotherapy to the CR intervention (n = 37) or usual care (n = 37). The intervention included guideline-directed management of cardiovascular risk factors, dietary counselling, and supervised exercise for 52 weeks. Cardiac magnetic resonance imaging, cardiopulmonary exercise testing, dual-energy x-ray absorptiometry, and serum biomarkers were acquired at baseline and 52 weeks. Results: There was no difference in the primary outcome, left ventricular ejection fraction (LVEF), between groups at 52 weeks (61% ± 6%). Other markers of cardiotoxicity, including high-sensitivity troponin I and brain natriuretic peptide, were similar between groups. However, total cholesterol (5.2 ± 0.8 mmol/L to 4.7 ± 0.8 mmol/L, P = 0.002) and low-density lipoprotein (3.0 ± 0.7 mmol/L to 2.4 ± 0.7 mmol/L, P < 0.001) decreased in the intervention group at 52 weeks and were unchanged in usual care. In all patients, adverse cardiac and metabolic changes occurred over 52 weeks including reductions in LVEF, left ventricular mass, high-density lipoprotein, lean body mass, insulin-like growth factor-1, as well as increased triglycerides, whole-body and truncal fat mass (all P < 0.050). Conclusions: The CR-modeled intervention had no effect on LVEF or biomarkers of cardiotoxicity. Future lifestyle intervention trials in patients with breast cancer should consider targeting other risk factors associated with incident cardiovascular disease. (Multidisciplinary Team IntervenTion in CArdio-ONcology [TITAN Study] [TITAN]; NCT01621659).

Remote ischaemic conditioning in ST elevation myocardial infarction: a registry-based randomised trial.

OBJECTIVES: Remote ischaemic conditioning (RIC) has been tested as a possible strategy for mitigating reperfusion injury in ST elevation myocardial infarction (STEMI) with primary percutaneous coronary intervention (PPCI). However, surrogate outcomes have shown inconsistent effects with lack of clinical correlation. METHODS: We performed a registry-based randomised study of patients with STEMI allocated to RIC (4 cycles of blood pressure cuff inflation to 200 mm Hg for 5 min of ischaemia followed by 5 min of reperfusion) or standard of care (SOC) during PPCI. We examined the associations of RIC on core laboratory measurements of myocardial perfusion, infarct size (IS), left ventricular (LV) performance and clinical outcomes. RESULTS: A total of 252 patients were enrolled. The median age was 61 (IQR: 55-70) years and 72.8% were male. Sum ST segment deviation resolution ≥50% was similar between RIC and SOC (65.2% vs 55.7%, p=0.269). In those with 3-day cardiovascular MRI (n=88), no difference in median (25th, 75th percentiles) IS (14.9% (4.5%, 23.1%) vs 16.1% (3.3%, 22.0%), p=0.980), LV dimensions (LV end-diastolic volume index: 78.7 (71.1, 91.2) mL/m2 vs 79.9 (71.2, 88.8) mL/m2, p=0.630; LV end-systolic volume index: 48.8 (35.7, 51.4) mL/m2 vs 37.9 (31.8, 47.5) mL/m2, p=0.551) or ejection fraction (50.0% (41.0%-55.0%) vs 50.0% (43.0%-56.0%), p=0.554) was demonstrated. Similar results were observed with 90-day cardiovascular MRI. At 1 year, the clinical composite of death, congestive heart failure, cardiogenic shock and recurrent myocardial infarction was similar in RIC and SOC (21.7% vs 13.3%, p=0.110). CONCLUSIONS: In a contemporary registry-based randomised study of patients with STEMI undergoing PPCI, adjunctive therapy with RIC did not improve myocardial perfusion, reduce IS or alter LV performance. Consequently, there was no difference in clinical outcomes within 1 year. TRIAL REGISTRATION NUMBER: NCT03930589.

Utility of FDG PET and Cardiac MRI in Diagnosis and Monitoring of Immunosuppressive Treatment in Cardiac Sarcoidosis.

PURPOSE: To compare the contributions of cardiac MRI and PET in the diagnosis and management of cardiac sarcoidosis (CS), with particular reference to quantitative measures. MATERIALS AND METHODS: This is a retrospective, observational study of 31 patients (mean age, 45.7 years) with proven extracardiac sarcoidosis and possible CS who were investigated with fluorine 18 fluorodeoxyglucose (FDG) PET/CT and cardiac MRI. Patients were treated at physicians' discretion with repeat combined imaging after an interval of 102-770 days (median, 228 days). RESULTS: Significant myocardial FDG uptake was shown on visit 1 (myocardial maximum standardized uptake value [SUVmax] > 3.6) in 17 of 22 patients who were subsequently treated. Myocardial SUVmax decreased at follow-up (6.5 to 4.0; P < .01) and was matched by significant decreases in FDG-avid lung and mediastinal node disease. A volumetric measure of myocardium above a threshold SUV (cardiac metabolic volume) decreased from a mean of 42.5 to a mean of 4.1 (P < .001). This was associated with significant improvement in the left ventricular ejection fraction (LVEF) (45.8 increasing to 50.9; P < .031). There was no change in volume of late gadolinium enhancement at treatment. Patients who were untreated showed no change in any FDG PET or cardiac MRI parameter. CONCLUSION: Myocardial FDG uptake in patients suspected of having CS is presumed to represent active inflammation. When treated with corticosteroids, this resolved or regressed at follow-up, with an improvement in LVEF and FDG-avid thoracic disease. Patients who were untreated showed no change in any parameter. Quantification of FDG-avid myocardium using cardiac metabolic volume is proposed as a useful objective measure for assessing response to therapy.© RSNA, 2020See also commentary by Gutberlet in this issue.

Sarcoidosis: a prospective observational cohort from Northern Alberta.

INTRODUCTION: Sarcoidosis is a multi-system disease reported to occur with a higher incidence in Alberta than many other health jurisdictions within and outside of Canada. The reasons for this higher incidence are currently not known. Exposure to beryllium can result in a clinically and radiologically identical disease to sarcoidosis. The purpose of our study was to identify patterns with potential occupational or environmental exposures to beryllium amongst individuals with sarcoidosis in Alberta through a tertiary referral center. METHODS: A prospective observational study was carried out at the University of Alberta Hospital. Patients with confirmed sarcoidosis (stages 0-4) were recruited from subspecialty clinics (Respirology, Cardiology, Neurology and Occupational Health). A predetermined list of industries thought to involve potentially relevant exposures for the development of sarcoidosis was used to capture current and previous exposure history. Results were entered into a database and where possible verified by comparing with existing electronic medical records (including histories, physical examination, diagnostic imaging and physiology). RESULTS: A total of 45 patients were recruited, 25 men and 20 women. Of these, 84% of participants reported working in or being exposed to an industry/environment suspected of contributing to development of sarcoidosis over their lifetime. The most frequently reported exposures were within farming and agriculture (27%), oil and gas (20%), metalworking and handling animals (18%). CONCLUSIONS: Amongst this cohort, a high proportion reported working with a potentially relevant exposure. Individuals being assessed for sarcoidosis should have their most responsible physician elicit a detailed work and environmental history. (Sarcoidosis Vasc Diffuse Lung Dis 2020; 37 (4): e2020014).

Quantitative blood flow evaluation of vasodilation-stress compared with dobutamine-stress in patients with end-stage liver disease using 82Rb PET/CT.

BACKGROUND: Our aim was to determine if end-stage liver disease (ESLD) is associated with an attenuated response to vasodilator-stress or dobutamine-stress using 82Rb-PET MPI with blood flow quantification. METHODS AND RESULTS: Pre-liver transplant patients who had a normal dipyridamole-stress (n = 27) or dobutamine-stress (n = 26) 82Rb PET/CT MPI study with no identifiable coronary artery calcium were identified retrospectively and compared to a prospectively identified low-risk of liver disease dipyridamole-stress control group (n = 20). The dipyridamole-stress liver disease group had a lower myocardial flow reserve (MFR) (1.89 ± 0.79) than the control group (2.79 ± 0.96, P < .05). The dobutamine-stress group had a higher MFR than both other groups (3.69 ± 1.49, P < .05). A moderate negative correlation between MELD score and MFR was demonstrated for the dipyridamole-stress liver disease group (r = - 0.473, P < .05). This correlation was not observed for the dobutamine-stress liver disease group (r = - 0.253, P = .21). The liver failure group as a whole (n = 53) had a higher resting myocardial blood flow (0.97 ± 0.33 mL/min/g) than the control group (0.82 ± 0.26, P < .05). CONCLUSION: Dipyridamole demonstrates an attenuated vasodilatory response in ESLD patients compared to a non-ESLD control group related to higher resting blood flow and comparatively reduced stress blood flow. Dobutamine does not demonstrate this effect implying it may be the preferred pharmacologic MPI stress agent for ESLD patients.

18F-Sodium Fluoride Imaging of Coronary Atherosclerosis in Ambulatory Patients With Diabetes Mellitus.

Objective- Although patients with diabetes mellitus (DM) are considered at high risk of cardiovascular events, there is growing evidence that this notion is incorrect. Atherosclerosis imaging may identify patients at risk. Approach and Results- We performed coronary atherosclerosis with 18F-sodium fluoride (NaF) positron emission tomography/computed tomography and gated chest computed tomography for coronary artery calcium in 88 consecutive ambulatory patients with DM on a stable medical regimen. NaF has been shown to localize avidly in culprit lesions of patients with acute coronary syndromes and may identify unstable plaques. NaF activity was measured as target (coronary arteries)-to-background (left ventricular pool) ratio (TBR). High TBR was defined as ≥1.5. The mean age of the cohort was 54±14 years, 55% had type 2 DM, 65% were men, the median HgbA1c (hemoglobin A1c) and LDL (low-density lipoprotein) cholesterol were 7.5% (interquartile range, 7.1-8.5) and 1.9 mmol/L (interquartile range, 1.5-2.6), respectively. Mean coronary artery calcium score was 374±773, and median TBR was 1.2. Coronary artery TBR ≥1.5 was detected in 13 (15%) patients. In univariable analyses, male sex ( P=0.0002), estimated glomerular filtration rate ( P=0.02), and total coronary artery calcium score ( P=0.04) were associated with TBR. In multivariable analyses, TBR >median was associated with male sex ( P=0.0001) and statin use ( P=0.042). Conclusions- In ambulatory patients with DM asymptomatic for cardiovascular disease, the prevalence of potentially vulnerable plaques detected with NaF was low, but in the absence of follow-up data at this stage, we cannot assess the import of this information. Future research will establish whether NaF imaging helps risk stratify patients with DM. Clinical Trial Registration- URL: http://www.clinicaltrials.gov . Unique identifier: NCT03530176.

Comparison of epicardial adipose tissue radiodensity threshold between contrast and non-contrast enhanced computed tomography scans: A cohort study of derivation and validation.

BACKGROUND AND AIMS: Epicardial adipose tissue (EAT) volume derived from contrast enhanced (CE) computed tomography (CT) scans is not well validated. We aim to establish a reliable threshold to accurately quantify EAT volume from CE datasets. METHODS: We analyzed EAT volume on paired non-contrast (NC) and CE datasets from 25 patients to derive appropriate Hounsfield (HU) cutpoints to equalize two EAT volume estimates. The gold standard threshold (-190HU, -30HU) was used to assess EAT volume on NC datasets. For CE datasets, EAT volumes were estimated using three previously reported thresholds: (-190HU, -30HU), (-190HU, -15HU), (-175HU, -15HU) and were analyzed by a semi-automated 3D Fat analysis software. Subsequently, we applied a threshold correction to (-190HU, -30HU) based on mean differences in radiodensity between NC and CE images (ΔEATrd = CE radiodensity - NC radiodensity). We then validated our findings on EAT threshold in 21 additional patients with paired CT datasets. RESULTS: EAT volume from CE datasets using previously published thresholds consistently underestimated EAT volume from NC dataset standard by a magnitude of 8.2%-19.1%. Using our corrected threshold (-190HU, -3HU) in CE datasets yielded statistically identical EAT volume to NC EAT volume in the validation cohort (186.1 ±â€¯80.3 vs. 185.5 ±â€¯80.1 cm3, Δ = 0.6 cm3, 0.3%, p = 0.374). CONCLUSIONS: Estimating EAT volume from contrast enhanced CT scans using a corrected threshold of -190HU, -3HU provided excellent agreement with EAT volume from non-contrast CT scans using a standard threshold of -190HU, -30HU.

Canadian Association of Radiologists Radiation Protection Working Group: Automated Patient-Specific Dose Registries­What Are They and What Are They Good for?

Medical radiation should be used appropriately and with a dose as low as reasonably achievable. Dose monitoring technologies have been developed that automatically accumulate patient dose indicators, providing effective dose estimates and patient-specific dose histories. Deleterious radiation related events have prompted increased public interest in the safe use of medical radiation. Some view individualized patient dose histories as a tool to help manage the patient dose. However, it is imperative that dose monitoring technologies be evaluated on the outcomes of dose reduction and effective patient management. Patient dose management needs to be consistent with the widely accepted linear no-threshold model of stochastic radiation effects. This essay reviews the attributes and limitations of dose monitoring technologies to provoke discussion regarding resource allocation in the current fiscally constrained health care system.

Imaging of vascular complications and their consequences following transplantation in the abdomen.

Transplantation is the surgical treatment of choice for end-stage organ failure. Transplantation procedures performed in the abdomen include liver, renal, pancreas, islet, intestinal, and multivisceral transplantations. Imaging plays a pivotal role in the posttransplantation setting for monitoring the transplant allograft and screening for complications. Knowledge of the surgical techniques employed in abdominal transplantation is essential because it facilitates radiologic understanding and interpretation of the posttransplantation anatomy. This article includes a basic description of the standard surgical techniques performed in the abdomen, with emphasis on the relevant vascular anastomotic reconstructions used. Posttransplantation complications can be broadly classified as vascular or nonvascular in origin. Many of these complications can be accurately depicted and characterized at imaging and dealt with definitively by using interventional radiology techniques, which can be graft- and life-saving and can obviate further complex surgical intervention. The article discusses imaging appearances of vascular complications and their consequences after transplantation in the abdomen. These vascular complications include arterial thrombosis, arterial stenosis, venous thrombosis and stenosis, arteriovenous fistula formation, and pseudoaneurysm formation. The relevant predisposing factors, clinical features, imaging appearances, and potential treatment options for vascular complications of various types of transplantation are presented in a logical and integrated fashion. Knowledge and imaging recognition of the posttransplantation vascular complications discussed in this article will aid radiologists in accurate imaging characterization and thereby facilitate appropriate clinical management and therapy.

A type A aortic dissection missed by non-cardiac gated contrast-enhanced computed tomography due to an aortic root dissection flap masquerading as an aortic valve apparatus: a case report.

INTRODUCTION: Though computed tomographic angiography has very high sensitivity and specificity to diagnose acute aortic dissection, false-negative studies can occur and secondary tests may be required to make the diagnosis. CASE PRESENTATION: We report the case of a 57-year-old Caucasian man with a typical presentation for acute type A aortic dissection in whom the initial non-cardiac gated computed tomographic angiogram was negative, leading to a delay in surgical management. Transesophageal echocardiography and post hoc 3D reconstruction of the original computed tomographic scan revealed a dissection flap confined to the aortic root, immediately superior to the sinuses of Valsalva and masquerading as part of the aortic valve apparatus. CONCLUSION: This case demonstrates that false-negative computed tomographic angiograms taken to rule out type A aortic dissection can occur and that secondary imaging tests, such as echocardiography, should be performed in cases in which the pre-test probability of aortic dissection is high. Cardiac gating of computed tomographic angiograms to exclude aortic dissection may enhance diagnostic accuracy.

Suppression of myocardial 18F-FDG uptake with a preparatory "Atkins-style" low-carbohydrate diet.

OBJECTIVES: Physiological myocardial uptake of 18F-FDG during positron emission tomography can mask adjacent abnormal uptake in mediastinal malignancy and inflammatory cardiac diseases. Myocardial uptake is unpredictable and variable. This study evaluates the impact of a low-carbohydrate diet in reducing myocardial FDG uptake. METHOD: Patients attending for clinically indicated oncological FDG PET were asked to have an "Atkins-style" low-carbohydrate diet (less than 3 g) the day before examination and an overnight fast. A total of 120 patients following low-carbohydrate diet plus overnight fast were compared with 120 patients prepared by overnight fast alone. Patients having an Atkins-style diet also completed a diet compliance questionnaire. SUV(max) and SUV(mean) for myocardium, blood pool and liver were measured in both groups. RESULTS: Myocardial SUV(max) fell from 3.53 ± 2.91 in controls to 1.77 ± 0.91 in the diet-compliant group. 98 % of diet-compliant patients had a myocardial SUV(max) less than 3.6 compared with 67 % of controls. Liver and blood pool SUV(max) rose from 2.68 ± 0.49 and 1.82 ± 0.30 in the control group to 3.14 ± 0.57 and 2.06 ± 0.30. CONCLUSION: An Atkins-style diet the day before PET, together with an overnight fast, effectively suppresses myocardial FDG uptake. KEY POINTS : • Low-carbohydrate diet (LCD) the day before PET suppresses myocardial FDG uptake. • LCD before PET increases liver and blood pool SUV ( max ) and SUV ( mean ). • Suppression of myocardial uptake may improve PET imaging of thoracic disease. • Suppression of myocardial uptake may help imaging cardiac inflammatory disease with PET.

Assessment of Myocardial Scar; Comparison Between F-FDG PET, CMR and Tc-Sestamibi.

OBJECTIVE: Patients with heart failure and ischaemic heart disease may obtain benefit from revascularisation if viable dysfunctional myocardium is present. Such patients have an increased operative risk, so it is important to ensure that viability is correctly identified. In this study, we have compared the utility of 3 imaging modalities to detect myocardial scar. DESIGN: Prospective, descriptive study. SETTING: Tertiary cardiac centre. PATIENTS: 35 patients (29 male, average age 70 years) with coronary artery disease and symptoms of heart failure (>NYHA class II). INTERVENTION: Assessment of myocardial scar by (99)Tc-Sestamibi (MIBI), (18)F-flurodeoxyglucose (FDG) and cardiac magnetic resonance (CMR). OUTCOME MEASURE: The presence or absence of scar using a 20-segment model. RESULTS: More segments were identified as nonviable scar using MIBI than with FDG or CMR. FDG identified the least number of scar segments per patient (7.4 +/- 4.8 with MIBI vs. 4.9 +/- 4.2 with FDG vs. 5.8 +/- 5.0 with CMR, p = 0.0001 by ANOVA). The strongest agreement between modalities was in the anterior wall with the weakest agreement in the inferior wall. Overall, the agreement between modalities was moderate to good. CONCLUSION: There is considerable variation amongst these 3 techniques in identifying scarred myocardium in patients with coronary disease and heart failure. MIBI and CMR identify more scar than FDG. We recommend that MIBI is not used as the sole imaging modality in patients undergoing assessment of myocardial viability.

Renal artery stenosis evaluation: diagnostic performance of gadobenate dimeglumine-enhanced MR angiography--comparison with DSA.

PURPOSE: To prospectively determine diagnostic performance and safety of contrast material-enhanced (CE) magnetic resonance (MR) angiography with 0.1 mmol per kilogram of body weight gadobenate dimeglumine for depiction of significant steno-occlusive disease (> or =51% stenosis) of renal arteries, with digital subtraction angiography (DSA) as reference standard. MATERIALS AND METHODS: This multicenter study was approved by local institutional review boards; all patients provided written informed consent. Patient enrollment and examination at centers in the United States complied with HIPAA. Two hundred ninety-three patients (154 men, 139 women; mean age, 61.0 years) with severe hypertension (82.2%), progressive renal failure (11.3%), and suspected renal artery stenosis (6.5%) underwent CE MR angiography with three-dimensional spoiled gradient-echo sequences after administration of 0.1 mmol/kg gadobenate dimeglumine at 2 mL/sec. Anteroposterior and oblique DSA was performed in 268 (91.5%) patients. Three independent blinded reviewers evaluated CE MR angiographic images. Sensitivity, specificity, and accuracy of CE MR angiography for detection of significant steno-occlusive disease (> or =51% vessel lumen narrowing) were determined at segment (main renal artery) and patient levels. Positive and negative predictive values and positive and negative likelihood ratios were determined. Interobserver agreement was analyzed with generalized kappa statistics. A safety evaluation (clinical examination, electrocardiogram, blood and urine analysis, monitoring for adverse events) was performed. RESULTS: Of 268 patients, 178 who were evaluated with MR angiography and DSA had significant steno-occlusive disease of renal arteries at DSA. Sensitivity, specificity, and accuracy of CE MR angiography for detection of 51% or greater stenosis or occlusion were 60.1%-84.1%, 89.4%-94.7%, and 80.4%-86.9%, respectively, at segment level. Similar values were obtained for predictive values and for patient-level analyses. Few CE MR angiographic examinations (1.9%-2.8%) were technically inadequate. Interobserver agreement for detection of significant steno-occlusive disease was good (79.9% agreement; kappa = 0.69). No safety concerns were noted. CONCLUSION: CE MR angiography performed with 0.1 mmol/kg gadobenate dimeglumine, compared with DSA, is safe and provides good sensitivity, specificity, and accuracy for detection of significant renal artery steno-occlusive disease.

State-of-the-art imaging techniques in chronic thromboembolic pulmonary hypertension.

It is important to differentiate chronic thromboembolic pulmonary hypertension (CTEPH) from other forms of pulmonary hypertension (PH) to target treatment and optimize therapeutic outcome. Misdiagnosis is common, and high-quality imaging is essential if CTEPH is to be diagnosed correctly. In addition to making a diagnosis, imaging helps identify patients for surgery, aids surgical planning, and provides postsurgical monitoring. Ventilation-perfusion scintigraphy and pulmonary angiography have been the mainstay of diagnosis and surgical assessment for many years, but cross-sectional techniques are rapidly taking over. Echocardiography is used to confirm or refute the presence of PH and to identify cardiac causes if PH is present. For patients with PH but no evidence of cardiac disease, multislice computed tomography (CT) is the next best step. CT distinguishes CTEPH from idiopathic arterial PH, evaluates underlying lung disease, and may help identify rarer causes of PH. CT is quick, widely available, and inexpensive. There is, however, a significant radiation burden, and it is unsuitable for serial examinations. Magnetic resonance (MR) involves no ionizing radiation and makes an ideal alternative. When combined with techniques for measuring ventricular function and blood flow, MR provides unique insight into structure and function. CT and MR are complementary techniques, and together they represent the future of imaging in PH. How they might be used in routine clinical practice is presented as a diagnostic algorithm developed at Papworth Hospital, the United Kingdom's national center for surgical treatment of CTEPH.

Are stentless valves superior to modern stented valves? A prospective randomized trial.

BACKGROUND: It is presumed that stentless aortic bioprostheses are hemodynamically superior to stented bioprostheses. A prospective randomized controlled trial was undertaken to compare stentless versus modern stented valves. METHODS AND RESULTS: Patients with severe aortic valve stenosis (n=161) undergoing aortic valve replacement (AVR) were randomized intraoperatively to receive either the C-E Perimount stented bioprosthesis (n=81) or the Prima Plus stentless bioprosthesis (n =80). We assessed left ventricular mass (LVM) regression with transthoracic echocardiography (TTE) and magnetic resonance imaging (MRI). Transvalvular gradients were measured postoperatively by Doppler echocardiography to compare hemodynamic performance. There was no difference between groups with regard to age, symptom status, need for concomitant coronary artery bypass surgery, or baseline LVM. LVM regressed in both groups but with no significant difference between groups at 1 year. In a subset of 50 patients, MRI was also used to assess LVM regression, and again there was no significant difference between groups at 1 year. Hemodynamic performance of the 2 valves was similar with no difference in mean and peak systolic transvalvular gradients 1 year after surgery. In patients with reduced ventricular function (left ventricular ejection fraction [LVEF] <60%), there was a significantly greater improvement in LVEF from baseline to 1 year in stentless valve recipients. CONCLUSIONS: Both stented and stentless bioprostheses are associated with excellent clinical and hemodynamic outcomes 1 year after AVR. Comparable hemodynamics and LVM regression can be achieved using a second-generation stented pericardial bioprosthesis. In patients with ventricular impairment, stentless bioprostheses may allow for greater improvement in left ventricular function postoperatively.

Abdominal and iliac arterial stenoses: comparative double-blinded randomized study of diagnostic accuracy of 3D MR angiography with gadodiamide or gadopentetate dimeglumine.

PURPOSE: To prospectively evaluate accuracy of gadolinium-enhanced three-dimensional (3D) magnetic resonance (MR) angiography with gadodiamide and gadopentetate dimeglumine (0.1 mmol/kg), with intraarterial DSA as reference standard, for imaging abdominal and iliac arterial stenoses. MATERIALS AND METHODS: The study was approved by all institutional review boards; informed consent was obtained from each subject before procedures. Two hundred forty-seven subjects were included; 240 received either contrast agent and were available for safety analysis; 222 were available for accuracy analysis. Enhanced 3D MR angiography and DSA were performed; image data were evaluated in a double-blinded randomized study. Stenoses were classified as not relevant (<50% stenosis) or relevant (> or =50%). For detection of main stenosis, accuracy with enhanced 3D MR angiography compared with that with DSA was determined. RESULTS: The difference in accuracy for imaging with gadodiamide and gadopentetate was 3.6%. Noninferiority was inferred because the lower bound of the exact two-sided 95% confidence interval was -10.1 and was above the noninferiority margin (-15%). Accuracy for detection of the main stenosis was low, 56.4% for gadodiamide and 52.8% for gadopentetate group. Subgroup analysis with exclusion of inferior mesenteric artery and internal iliac arteries and the most false-positive stenosis classifications yielded better results: 76.6% and 71.6%, respectively. Sensitivity, specificity, and negative and positive predictive values did not differ substantially between study groups. In the main analysis, values were 44%, 96%, 35%, and 97% for gadodiamide and 44%, 83%, 30%, and 90% for gadopentetate, respectively. In the subgroup analysis, values were 66%, 95%, 61%, and 96% for gadodiamide and 63%, 86%, 58%, and 88% for gadopentetate, respectively. CONCLUSION: Noninferiority of gadodiamide versus gadopentetate was verified based on the primary end point, which was accuracy for detection of the main stenosis with enhanced 3D MR angiography compared with DSA.