Use of 2D Sensitivity Encoding for Slow-Infusion Contrast-Enhanced Isotropic 3-T Whole-Heart Coronary MR Angiography.

OBJECTIVE. The purpose of this study was to improve the blood-pool signal-to-noise ratio (SNR) and blood-myocardium contrast-to-noise ratio (CNR) of slow-infusion 3-T whole-heart coronary MR angiography (MRA).SUBJECTS AND METHODS. In 2D sensitivity encoding (SENSE), the number of acquired k-space lines is reduced, allowing less radiofrequency excitation per cardiac cycle and a longer TR. The former can be exploited for signal enhancement with a higher radiofrequency excitation angle, and the latter leads to noise reduction due to lower data-sampling bandwidth. Both effects contribute to SNR gain in coronary MRA when spatial and temporal resolution and acquisition time remain identical. Numeric simulation was performed to select the optimal 2D SENSE pulse sequence parameters and predict the SNR gain. Eleven patients underwent conventional unenhanced and the proposed 2D SENSE contrast-enhanced coronary MRA acquisition. Blood-pool SNR, blood-myocardium CNR, visible vessel length, vessel sharpness, and number of side branches were evaluated.RESULTS. Consistent with the numeric simulation, using 2D SENSE in contrast-enhanced coronary MRA resulted in significant improvement in aortic blood-pool SNR (unenhanced vs contrast-enhanced, 37.5 +/- 14.7 vs 121.3 +/- 44.0; p < 0.05) and CNR (14.4 +/- 6.9 vs 101.5 +/- 40.8; p < 0.05) in the patient sample. A longer length of left anterior descending coronary artery was visualized, but vessel sharpness, coronary artery coverage, and image quality score were not improved with the proposed approach.CONCLUSION. In combination with contrast administration, 2D SENSE was found effective in improving SNR and CNR in 3-T whole-heart coronary MRA. Further investigation of cardiac motion compensation is necessary to exploit the SNR and CNR advantages and to achieve submillimeter spatial resolution.

La prothèse de St Jude medical chez les patients âges de plus de 65 ans [St Jude's Medical prosthesis in patients over 65].

Between September 1979 and December 1982, 56 St Jude Medical valvular prostheses were implanted in 54 patients over 65 years of age. Surgery consisted in simple aortic valve replacement (35 cases), simple mitral valve replacement (12 cases), double aortic and mitral valve replacement (2 cases), valve replacement and coronary artery bypass surgery (3 cases), aortic valve replacement and replacement of the ascending aorta (1 case) and mitral valve replacement and tricuspid annuloplasty (1 case). The operative mortality (within 30 days of surgery) was 3.5% (2 cases). Patients were assessed by clinical examination, ECG, chest X-ray, echocardiogram and laboratory investigations on average 19 months after surgery. There were 3 late deaths (1 endocarditis, 1 cardiac failure and 1 subdural haematoma). No cases of significant haemolysis were observed. There were no cases of thrombosis of the valve or any deaths directly related to the valve. Four patients had cerebral embolism (4.9% per patient/year). None were fatal and only 1 patient had sequellae. Clinical improvement was very significant; 96% of the patients are now in the NYHA Classes I and II whilst 80% were in Class III or IV before surgery. The cardiothoracic ratio decreased significantly from 0.56 to 0.51 (p less than 0.01). The authors conclude that elderly patients may derive great benefits from valvular cardiac surgery and that age in itself is not a contraindication to this type of surgery. The St Jude Medical prosthesis is an excellent prosthesis but thromboembolism remains a major problem as with other mechanical prostheses. Anticoagulation for life is essential.

Bias related to body mass index in pediatric echocardiographic z scores.

In pediatric echocardiography, cardiac dimensions are often normalized for weight, height, or body surface area (BSA). The combined influence of height and weight on cardiac size is complex and likely varies with age. We hypothesized that increasing weight for height, as represented by body mass index (BMI) adjusted for age, is poorly accounted for in Z scores normalized for weight, height, or BSA. We aimed to evaluate whether a bias related to BMI was introduced when proximal aorta diameter Z scores are derived from bivariate models (only one normalizing variable), and whether such a bias was reduced when multivariable models are used. We analyzed 1,422 echocardiograms read as normal in children ≤18 years. We computed Z scores of the proximal aorta using allometric, polynomial, and multivariable models with four body size variables. We then assessed the level of residual association of Z scores and BMI adjusted for age and sex. In children ≥6 years, we found a significant residual linear association with BMI-for-age and Z scores for most regression models. Only a multivariable model including weight and height as independent predictors produced a Z score free of linear association with BMI. We concluded that a bias related to BMI was present in Z scores of proximal aorta diameter when normalization was done using bivariate models, regardless of the regression model or the normalizing variable. The use of multivariable models with weight and height as independent predictors should be explored to reduce this potential pitfall when pediatric echocardiography reference values are evaluated.

Urgent reoperative transapical valve-in-valve shortly after a transapical aortic valve implantation.

Urgent reoperative transapical aortic valve-in-valve has never been proposed as a treatment option in case of a failed transcatheter aortic valve implantation (TAVI) or in case of worsening of an existing paravalvular leak, if this complication occurs right after, or a few days after, the primary transapical aortic valve implantation. Experienced surgeons should argue that after a transapical TAVI, the apex is damaged and fragile, with a high risk of irreparable ventricular tears and life-threatening bleeding if a second transapical procedure is scheduled during the acute phase. Nevertheless, if the patient is inoperable and the vascular status, including the ascending aorta, limits alternative accesses, the urgent reoperative transapical valve-in-valve becomes an alternative. We illustrate, for the first time ever, our experience with an 81-year old female patient who underwent a transapical (TA) TAVI with a Sapien? XT 23 mm. The day after the procedure, the patient haemodynamically worsened in combination with a worsening of a known (grade 1-2) paravalvular leak. Thus, on postoperative day two, an urgent transapical valve-in-valve was performed, and a second Sapien? XT 23 mm was placed, with an excellent haemodynamic result and absence of leak. The redo apical access did not appear very complicated and the postoperative recovery was uneventful.

Atrioventricular septal defects among infants in Europe: a population-based study of prevalence, associated anomalies, and survival.

OBJECTIVE: To describe the epidemiology of chromosomal and non-chromosomal cases of atrioventricular septal defects in Europe. METHODS: Data were obtained from EUROCAT, a European network of population-based registries collecting data on congenital anomalies. Data from 13 registries for the period 2000-2008 were included. RESULTS: There was a total of 993 cases of atrioventricular septal defects, with a total prevalence of 5.3 per 10,000 births (95% confidence interval 4.1 to 6.5). Of the total cases, 250 were isolated cardiac lesions, 583 were chromosomal cases, 79 had multiple anomalies, 58 had heterotaxia sequence, and 23 had a monogenic syndrome. The total prevalence of chromosomal cases was 3.1 per 10,000 (95% confidence interval 1.9 to 4.3), with a large variation between registers. Of the 993 cases, 639 cases were live births, 45 were stillbirths, and 309 were terminations of pregnancy owing to foetal anomaly. Among the groups, additional associated cardiac anomalies were most frequent in heterotaxia cases (38%) and least frequent in chromosomal cases (8%). Coarctation of the aorta was the most common associated cardiac defect. The 1-week survival rate for live births was 94%. CONCLUSION: Of all cases, three-quarters were associated with other anomalies, both chromosomal and non-chromosomal. For infants with atrioventricular septal defects and no chromosomal anomalies, cardiac defects were often more complex compared with infants with atrioventricular septal defects and a chromosomal anomaly. Clinical outcomes for atrioventricular septal defects varied between regions. The proportion of termination of pregnancy for foetal anomaly was higher for cases with multiple anomalies, chromosomal anomalies, and heterotaxia sequence.

10-year follow-up of a prospective randomized trial comparing bare-metal stenting with internal mammary artery grafting for proximal, isolated de novo left anterior coronary artery stenosis the SIMA (Stenting versus Internal Mammary Artery grafting) trial

OBJECTIVES: This study was designed to compare the long-term clinical outcome of coronary artery bypass grafting (CABG) with intracoronary stenting of patients with isolated proximal left anterior descending coronary artery. BACKGROUND: Although numerous trials have compared coronary angioplasty with bypass surgery, none assessed the clinical evaluation in the long term. METHODS: We evaluated the 10-year clinical outcome in the SIMA (Stent versus Internal Mammary Artery grafting) trial. Patients were randomly assigned to stent implantation versus CABG. RESULTS: Of 123 randomized patients, 59 underwent CABG and 62 received a stent (2 patients were excluded). Follow-up after 10 years was obtained for 98% of the randomized patients. Twenty-six patients (42%) in the percutaneous coronary intervention group and 10 patients (17%) in the CABG group reached an end point (p < 0.001). This difference was due to a higher need for additional revascularization. The incidences of death and myocardial infarction were identical at 10%. Progression of the disease requiring additional revascularization was rare (5%) and was similar for the 2 groups. Stent thrombosis occurred in 2 patients (3%). Angina functional class showed no significant differences between the 2 groups. CONCLUSIONS: Both stent implantation and CABG are safe and highly effective in relieving symptoms in patients with isolated, proximal left anterior descending coronary artery stenosis. Stenting with bare-metal stents is associated with a higher need for repeat interventions. The long-term prognosis for these patients is excellent with either mode of revascularization.

Steady-state equilibrium phase inversion recovery ON-resonant water suppression (IRON) MR angiography in conjunction with superparamagnetic nanoparticles. A robust technique for imaging within a wide range of contrast agent dosages.

PURPOSE: To investigate the ability of inversion recovery ON-resonant water suppression (IRON) in conjunction with P904 (superparamagnetic nanoparticles which consisting of a maghemite core coated with a low-molecular-weight amino-alcohol derivative of glucose) to perform steady-state equilibrium phase MR angiography (MRA) over a wide dose range. MATERIALS AND METHODS: Experiments were approved by the institutional animal care committee. Rabbits (n = 12) were imaged at baseline and serially after the administration of 10 incremental dosages of 0.57-5.7 mgFe/Kg P904. Conventional T1-weighted and IRON MRA were obtained on a clinical 1.5 Tesla (T) scanner to image the thoracic and abdominal aorta, and peripheral vessels. Contrast-to-noise ratios (CNR) and vessel sharpness were quantified. RESULTS: Using IRON MRA, CNR and vessel sharpness progressively increased with incremental dosages of the contrast agent P904, exhibiting constantly higher contrast values than T1 -weighted MRA over a very wide range of contrast agent doses (CNR of 18.8 ± 5.6 for IRON versus 11.1 ± 2.8 for T1 -weighted MRA at 1.71 mgFe/kg, P = 0.02 and 19.8 ± 5.9 for IRON versus -0.8 ± 1.4 for T1-weighted MRA at 3.99 mgFe/kg, P = 0.0002). Similar results were obtained for vessel sharpness in peripheral vessels, (Vessel sharpness of 46.76 ± 6.48% for IRON versus 33.20 ± 3.53% for T1-weighted MRA at 1.71 mgFe/Kg, P = 0.002, and of 48.66 ± 5.50% for IRON versus 19.00 ± 7.41% for T1-weighted MRA at 3.99 mgFe/Kg, P = 0.003). CONCLUSION: Our study suggests that quantitative CNR and vessel sharpness after the injection of P904 are consistently higher for IRON MRA when compared with conventional T1-weighted MRA. These findings apply for a wide range of contrast agent dosages.

Nodal staging in colorectal cancer: should distant lymph nodes be recovered in surgical specimens?

To assess the value of sampling lymph nodes located far sidelong colorectal cancer specimens, we analyzed retrospectively surgical specimens from 345 colorectal cancer patients. The mesocolic and perirectal fat was divided into 2 fractions: close to (<5 cm) and distant from (>5 cm) the tumor. Tumors were located in the cecum (n = 61), ascending colon (n = 29), transverse colon (n = 31), descending colon (n = 27), sigmoid colon (n = 108), and rectum (n = 89). The median number of lymph nodes sampled was 17 in both fractions (range, 4-66), 12 (range, 0-46) in the close fraction, and 3 (range, 0-33) in the distant fraction. There were 169 pN0, 104 pN1, and 72 pN2 cases. The pN staging was accurate in all cases except 10 based on the close fraction alone; of these, 6 were upstaged from pN0 to pN1 and 4 from pN1 to pN2 when the distant fraction was considered. Among pN1-upstaged cases, 5 were rectal (3/5 with neoadjuvant radiotherapy) and 1 colonic. In the colon, we found that lymph node location is more important than lymph node number because metastatic lymph nodes were present mostly in the peritumoral area. This suggests that lymph nodes should be initially recovered from the pericolic fat close to the tumor. If there are less than 4 positive lymph nodes and less than 12 lymph nodes examined in total, additional lymph nodes should be retrieved from the distal fraction for potential upstaging. In the rectum, systematic sampling of close and distant lymph nodes is mandatory because in rare cases, metastases are detected only in distant lymph nodes, particularly in patients who have undergone neoadjuvant radiotherapy.

The Macrocirculation and Microcirculation of Hypertension.

Changes in vascular structure that accompany hypertension may contribute to hypertensive end-organ damage. Both the macrovascular and microvascular levels should be considered, as interactions between them are believed to be critically important. Regarding the macrocirculation, the article first reviews basic concepts of vascular biomechanics, such as arterial compliance, arterial distensibility, and stress-strain relationships of arterial wall material, and then reviews how hypertension affects the properties of conduit arteries, particularly examining evidence that it accelerates the progressive stiffening that normally occurs with advancing age. High arterial stiffness may increase central systolic and pulse pressure by two different mechanisms: 1) Abnormally high pulse wave velocity may cause pressure waves reflected in the periphery to reach the central aorta in systole, thus augmenting systolic pressure; 2) In the elderly, the interaction of the forward pressure wave with high arterial stiffness is mostly responsible for abnormally high pulse pressure. At the microvascular level, hypertensive disease is characterized by inward eutrophic or hypertrophic arteriolar remodeling and capillary rarefaction. These abnormalities may depend in part on the abnormal transmission of highly pulsatile blood pressure into microvascular networks, especially in highly perfused organs with low vascular resistance, such as the kidney, heart, and brain, where it contributes to hypertensive end-organ damage.

Transapical aortic valve replacement in extreme-risk patients: outcome, risk factors and mid-term results.

OBJECTIVES: Transcatheter aortic valve replacement (TAVR) provides good results in selected high-risk patients. However, it is unclear whether this procedure carries advantages in extreme-risk profile patients with logistic EuroSCORE above 35%. METHODS: From January 2009 to July 2011, of a total number of 92 transcatheter aortic valve procedures performed, 40 'extreme-risk' patients underwent transapical TAVR (TA-TAVR) (EuroSCORE above 35%). Variables were analysed as risk factors for hospital and mid-term mortality, and a 2-year follow-up (FU) was obtained. RESULTS: The mean age was: 81 ± 10 years. Twelve patients (30%) had chronic pulmonary disease, 32 (80%) severe peripheral vascular disease, 14 (35%) previous cardiac surgery, 19 (48%) chronic renal failure (2 in dialysis), 7 (17%) previous stroke (1 with disabilities), 3 (7%) a porcelain aorta and 12 (30%) were urgent cases. Mean left ventricle ejection fraction (LVEF) was 49 ± 13%, and mean logistic EuroSCORE was 48 ± 11%. Forty stent-valves were successfully implanted with six Grade-1 and one Grade-2 paravalvular leakages (success rate: 100%). Hospital mortality was 20% (8 patients). Causes of death following the valve academic research consortium (VARC) definitions were: life-threatening haemorrhage (1), myocardial infarction (1), sudden death (1), multiorgan failure (2), stroke (1) and severe respiratory dysfunction (2). Major complications (VARC definitions) were: myocardial infarction for left coronary ostium occlusion (1), life-threatening bleeding (2), stroke (2) and acute kidney injury with dialysis (2). Predictors for hospital mortality were: conversion to sternotomy, life-threatening haemorrhage, postoperative dialysis and long intensive care unit (ICU) stay. Variables associated with hospital mortality were: conversion to sternotomy (P = 0.03), life-threatening bleeding (P = 0.02), acute kidney injury with dialysis (P = 0.03) and prolonged ICU stay (P = 0.02). Mean FU time was 24 months: actuarial survival estimates for all-cause mortality at 6 months, 1 year, 18 months and 2 years were 68, 57, 54 and 54%, respectively. Patients still alive at FU were in good clinical condition, New York Heart Association (NYHA) class 1-2 and were never rehospitalized for cardiac decompensation. CONCLUSIONS: TA-TAVR in extreme-risk patients carries a moderate risk of hospital mortality. Severe comorbidities and presence of residual paravalvular leakages affect the mid-term survival, whereas surviving patients have an acceptable quality of life without rehospitalizations for cardiac decompensation.

Transaortic transcatheter aortic valve replacement with the Sapien? valve and the first generations of Ascendra?.

Traditionally, the transcatheter aortic valve replacement is performed through a transapical, a transfemoral or a trans-subclavian approach. Recently, the transaortic approach for transcatheter aortic valve replacement through the distal part of the ascending aorta was successfully implemented in order to avoid peripheral vascular access-related complications and apical life-threatening haemorrhage. The Sapien? stent valve has great transaortic potential because it can be loaded 'upside down' in different generations of delivery systems. However, because of their health regulatory systems and despite the launch, in 2012, of the latest generation of the Ascendra? delivery system, the Ascendra+?, specifically designed for transapical and transaortic valve placements, several countries are still using the first generations of Ascendra? (Ascendra? 1 and 2). This device was specifically designed for transapical procedures, and retrograde stent-valve positioning through the stenotic aortic valve may be very challenging and risk the integrity of the aorta. We describe the manoeuvre required in order to pass the stenotic aortic valve safely in a retrograde direction using the Sapien? stent valve and the first generations of Ascendra?.

Aortic vessel wall magnetic resonance imaging at 3.0 Tesla: a reproducibility study of respiratory navigator gated free-breathing 3D black blood magnetic resonance imaging.

The purpose of this study was to evaluate a free-breathing three-dimensional (3D) dual inversion-recovery (DIR) segmented k-space gradient-echo (turbo field echo [TFE]) imaging sequence at 3T for the quantification of aortic vessel wall dimensions. The effect of respiratory motion suppression on image quality was tested. Furthermore, the reproducibility of the aortic vessel wall measurements was investigated. Seven healthy subjects underwent 3D DIR TFE imaging of the aortic vessel wall with and without respiratory navigator. Subsequently, this sequence with respiratory navigator was performed twice in 10 healthy subjects to test its reproducibility. The signal-to-noise (SNR), contrast-to-noise ratio (CNR), vessel wall sharpness, and vessel wall volume (VWV) were assessed. Data were compared using the paired t-test, and the reproducibility of VWV measurements was evaluated using intraclass correlation coefficients (ICCs). SNR, CNR, and vessel wall sharpness were superior in scans performed with respiratory navigator compared to scans performed without. The ICCs concerning intraobserver, interobserver, and interscan reproducibility were excellent (0.99, 0.94, and 0.95, respectively). In conclusion, respiratory motion suppression substantially improves image quality of 3D DIR TFE imaging of the aortic vessel wall at 3T. Furthermore, this optimized technique with respiratory motion suppression enables assessment of aortic vessel wall dimensions with high reproducibility.

Correction for heart rate variability during 3D whole heart MR coronary angiography.

PURPOSE: To evaluate the effect of a real-time adaptive trigger delay on image quality to correct for heart rate variability in 3D whole-heart coronary MR angiography (MRA). MATERIALS AND METHODS: Twelve healthy adults underwent 3D whole-heart coronary MRA with and without the use of an adaptive trigger delay. The moment of minimal coronary artery motion was visually determined on a high temporal resolution MRI. Throughout the scan performed without adaptive trigger delay, trigger delay was kept constant, whereas during the scan performed with adaptive trigger delay, trigger delay was continuously updated after each RR-interval using physiological modeling. Signal-to-noise, contrast-to-noise, vessel length, vessel sharpness, and subjective image quality were compared in a blinded manner. RESULTS: Vessel sharpness improved significantly for the middle segment of the right coronary artery (RCA) with the use of the adaptive trigger delay (52.3 +/- 7.1% versus 48.9 +/- 7.9%, P = 0.026). Subjective image quality was significantly better in the middle segments of the RCA and left anterior descending artery (LAD) when the scan was performed with adaptive trigger delay compared to constant trigger delay. CONCLUSION: Our results demonstrate that the use of an adaptive trigger delay to correct for heart rate variability improves image quality mainly in the middle segments of the RCA and LAD.