Jjm Jos Westenberg

Aortic elasticity and size are associated with aortic regurgitation and left ventricular dysfunction in tetralogy of Fallot after pulmonary valve replacement

Background: Aortic wall pathology and concomitant aortic dilatation have been described in tetralogy of Fallot (TOF) patients, which may negatively affect aortic valve and left ventricular systolic function. Objective: To assess aortic dimensions, aortic elasticity, aortic valve competence and biventricular function in repaired TOF patients after pulmonary valve replacement (PVR) using magnetic resonance imaging (MRI). Methods: MRI was performed in 16 patients with TOF after PVR (10 male; mean age 31 years (SD 15)) and 16 age and gender-matched healthy subjects. Results: TOF patients showed aortic root dilatation (mean difference 7.8–8.8 mm, p<0.01 at all four predefined levels) and reduced aortic elasticity (pulse wave velocity in aortic arch 5.5 m/s (1.2) vs 4.6 m/s (0.9), p = 0.04; aortic root distensibility 1.4/10−3 mm Hg (1.7) vs 5.7/10−3 mm Hg (3.6), p<0.01). Minor degrees of aortic regurgitation (AR) (AR fraction 6% (8) vs 1% (1), p<0.01) and reduced left ventricular ejection fraction (LVEF) were present (51% (8) vs 58% (6), p = 0.01), whereas right ventricular ejection fraction (RVEF) was within normal limits (47% (8) vs 52% (7), p = 0.06). The degree of AR fraction was associated with dilatation of the aortic root (r  =  0.39–0.49, p<0.05) and reduced aortic root distensibility (r  =  0.44, p = 0.02), whereas reduced LVEF was correlated with degree of AR and RVEF (r  =  0.41, p = 0.02 and r  =  0.49, p<0.01, respectively). Conclusions: Aortic root dilatation and reduced aortic elasticity are frequently present in patients with TOF, in addition to minor degrees of AR and reduced left ventricular systolic function. Aortic wall pathology in repaired TOF patients may therefore represent a separate mechanism leading to left ventricular dysfunction, as part of a multifactorial process of left ventricular dysfunction.

Recovery of right and left ventricular function after acute pulmonary embolism

AIM To evaluate recovery of cardiac function after acute pulmonary embolism (PE). MATERIALS AND METHODS Routine breath-held computed tomography (CT)-pulmonary angiography was performed in patients with suspected PE to confirm or exclude the diagnosis of PE at initial presentation. Electrocardiogram (ECG)-triggered cardiac CT was performed to assess biventricular function. After 6 months, cardiac magnetic resonance imaging (MRI) was performed. In total, 15 consecutive patients with PE and 10 without were studied. A significant change in ventricular volume was defined as a >15% change in end-diastolic or -systolic volumes (EDV, ESV), and significant ventricular function improvement as a >5% increase in ejection fraction (EF) as based on reported cut-off values. RESULTS Right and left ventricular (RV and LV) EDV and ESV changed non-significantly (<1.3%) in the patients without PE, indicating good comparability of those values measured by CT and MRI. PE patients with baseline normal RV function (RVEF ≥ 47%) revealed a >5% improvement in the RVEF (+5.4 ± 3.1%) due to a decrease in the RVESV. Patients with baseline abnormal RV function showed a >5% improvement in the RVEF (+14 ± 15%) due to decreases in both the RVESV and RVEDV. Furthermore, the LVEDV increased in this latter patient group. CONCLUSIONS The present study demonstrated an improvement in RV function in the majority of patients with PE, independent of baseline RV function. The degree of RV and LV recovery was dependent on the severity of baseline RV dysfunction.

Cardiac Strain and Rotation Analysis Using Multi-scale Optical Flow

Tagging MRI enables analysis of the local contractility of the cardiac left ventricle. It permits reliable assessment of local contractile dysfunction related to various cardiomyopathies. We present a multi-scale optical flow method, with Gabor filtering, for the extraction of dense motion fields from cardiac MR tagging. It is based on a multi-scale first-order extension of the classical optical flow constraint equation enabling the extraction first-order parameters such as rotation and strain. A quantitative validation study based on the phantom proposed by Young et al. showed excellent performance. Furthermore, strain patterns are presented for one ischemic patient case with known wall motion abnormalities and two volunteers. Patient circumferential strain abnormalities co-localize with enhanced areas in late-enhancement MRI. Rotation patterns are presented for the same patient and four volunteers. The rotation pattern described in the patient is strikingly different from that describing the volunteers.

Direct Myocardial Strain Assessment from Frequency Estimation in Tagging MRI

We propose a new method to analyse deformation of the cardiac left ventricular wall from tagging magnetic resonance images. The method exploits the fact that the time-dependent frequency covector field representing the tag pattern is tightly coupled to the myocardial deformation and not affected by tag fading. Deformation and strain tensor fields can be retrieved from local frequency estimates given at least n independent tagging sequences, where n denotes spatial dimension. Our method does not require knowledge of material motion or tag line extraction. We consider the conventional case of two tag directions, as well as the overdetermined case of four tag directions, which improves robustness. Additional scan time can be prevented by using one or two grid patterns consisting of multiple, simultaneously acquired tag directions. This concept is demonstrated on patient data. Tracking errors obtained for phantom data are smaller than those obtained by HARP, 0.32±0.14 px versus 0.53±0.07 px. Strain results for volunteers are compared with corresponding linearised strain fields derived from HARP.

Is Hepatic Triglyceride Content Associated with Aortic Pulse Wave Velocity and Carotid Intima-Media Thickness? The Netherlands Epidemiology of Obesity Study

Purpose To test the hypothesis that hepatic triglyceride content is associated with subclinical vascular impairment and is not confounded by various cardiometabolic risk factors. Materials and Methods This study was approved by the institutional review board, and all participants gave written informed consent. In this cross-sectional analysis of baseline measurements of the Netherlands Epidemiology of Obesity study, a population-based cohort study, 1899 participants (52% men; mean age, 55 years ± 6 [standard deviation]) underwent magnetic resonance (MR) spectroscopy and MR imaging to assess hepatic triglyceride content, aortic pulse wave velocity (PWV), and visceral fat. Carotid intima-media thickness (IMT) was acquired and measured by trained research nurses according to standard procedures. Multivariate regression analyses were used to study associations of hepatic triglyceride content with total and regional aortic PWV and carotid IMT while adjusting for several possible confounding factors, including the metabolic syndrome. Results Total aortic PWV (mean difference, 0.5 m/sec; 95% confidence interval [CI]: 0.3, 0.7) and carotid IMT (mean difference, 37 μm; 95% CI: 25, 49) were higher in participants with hepatic steatosis. After adjusting for various covariates, a 10-fold increase in hepatic triglyceride content was associated with an increased mean aortic PWV of 0.19 m/sec (95% CI: 0.03, 0.36) in total and an increased mean aortic PWV of 0.42 m/sec (95% CI: 0.03, 0.81) in the abdominal segment. A 10-fold increase in hepatic triglyceride content was also associated with an increased mean carotid IMT of 15 μm (95% CI: 0, 29) but not after additional adjustments for visceral and total body fat. Conclusion In this relatively large population-based cohort study, hepatic triglyceride content was associated with aortic pulse wave velocity and carotid IMT. These associations were only partly explained by the metabolic syndrome and visceral adiposity, suggesting a possible specific contribution of hepatic steatosis to subclinical vascular impairment.

Efficient reconstruction of cardiac LV surfaces using a 3D sparse ASM

Cardiac magnetic resonance imaging (MRI) has demonstrated to be the most accurate and reproducible tool for assessment of the cardiovascular system. Traditional quantification methods require acquisition of densely sampled data sets, resulting in increased analysis time. This paper investigates whether comparable quantification accuracy can be achieved with a combination of sparsely sampled data and using an active shape model (ASM) of the left ventricle

MARKED VARIATION OF MRI ASSESSED PULSE WAVE VELOCITY AND LEFT VENTRICULAR MASS IN HYPERTENSIVE PATIENTS WITH IDENTICAL CARDIOVASCULAR RISK: PP.35.448

Objective: The inter-individual variation of pulse wave velocity (PWV) and left ventricular mass index (LVM) in hypertensive patients stratified for cardiovascular risk is largely unknown. Insight in variation of PWV and LVM may help to further develop individualized approaches in diagnosis and treatment of hypertension. The aim of our study was to explore MRI assessed aortic PWV and LVM in patients with hypertension stratified for cardiovascular disease (CVD) risk profile. Design and Methods: Forty-six hypertensive patients without CVD or diabetes mellitus (28 women and 18 men; mean age ± standard deviation, 50.9years ± 7.5; mean systolic blood pressure, 151.6mmHg ± 22.1; mean diastolic blood pressure, 89.2mmHg ± 13.0) were enrolled. All patients underwent MRI measurement of aortic PWV and LVM. Left ventricular hypertrophy (LVH) was defined as LVM>85 g/m2 (male) and LVM>66.91 g/m2 (female). Patients were stratified using the SCORE prediction chart into 0%;1%; 2%; 3–4%; and =/>5% 10-year risk of CVD mortality. ANOVA was used for statistical analysis. Results: LVM was significantly correlated with systolic blood pressure (r = 0.39, p < 0.05). Mean (SD) PWV was not significantly different across the SCORE groups 0% to =/>5%; 6.4(±1.7), 7.0(±1.8), 7.2(±1.9), 7.7(±1.7), 7.8(±2.1) m/sec. In line with this observation, PWV showed marked variation and ranged from 4.6m/sec to 12.7m/sec showing a 3.2 fold increase from lowest to highest value. Mean (SD) LVM across the stratified groups were significantly different: 58.1(±16.3), 58.7(±10.0), 62.1(±9.2), 58.1(±5.3), 66.3(±12.1) g/m2 p = 0.001. However, also for LVM, marked inter-individual differences were observed. The highest LVM value was 2.2 fold higher compared to the lowest measured value (range: 43.0 g/m2 to 95.9 g/m2) and was found in the lowest stratum. Conclusions: Remarkable high MRI measured PWV and LVM values with marked inter-individual variability were observed in these hypertensive patients at low to intermediate cardiovascular risk. If some hypertensive patients are more vulnerable to end organ damage than other despite similar blood pressure and SCORE values, this implies treatment strategies should be reconsidered for these patients. Figure 1. No caption available.

PREVALENCE AND SIMULTANEOUS OCCURENCE OF MRI ASSESSED CARDIAC AND CEREBRAL TARGET ORGAN DAMAGE AND MICROALBUMINURIA: 7A.07

Objective: Target organ damage (TOD) contributes importantly to treatment decisions in patients with arterial hypertension. However, available evidence on the prevalence of multiple TOD is limited. We examined the prevalence and simultaneous occurrence of microalbuminuria (MA) and MRI assessed subclinical TOD of the heart and brain in patients with hypertension. Methods: Seventy-three patients with treated hypertension without known overt cardiovascular disease (41 women; 32 men; mean age ± sd, 44.5years ± 13.3; mean systolic blood pressure, 149.1 mmHg ± 23.9; mean diastolic blood pressure, 89.6 mmHg ± 13.1) were enrolled for the evaluation of subclinical TOD at our hypertension referral center. Patients underwent cardiac and cerebral MRI assessment in addition to standard evaluation including 24-h urine collection for MA. MA was used as a marker of renal TOD, increased left ventricular mass index (left ventricular hypertrophy -LVH- male >85.1 g/m2, female >66.9 g/m2) as marker for cardiac TOD, lacunar brain infarcts, periventricular and deep white matter hyperintensities (PWMH and DWMH) and brain-micro-bleeds (BMB) as markers for cerebral TOD. Results: In 49.3% of the patients TOD was observed. The prevalence of involvement of one, two or three organs was 38.8%, 9.0% and 1.5%, respectively. Microalbuminuria was present in 21.9% and LVH in 9.7% of the patients. Cerebral TOD was present in 30.1% of the patients defined as positive for at least one of following cerebral changes: PWMH (20.5%), SWMH (17.8%), lacunar brain infarcts (9.6%) and BMB (5.5%). The most frequent combinations were MA and cerebral TOD: 5.5% and LVH and cerebral TOD: 4.1%. Conclusions: This is the first time that clustering of MRI assessed TOD and MA are reported. Our results show that: (i) subclinical cerebral TOD is a frequently present phenotypic expression of hypertensive TOD; (ii) multiple target organ abnormalities were observed in approximately 10% of the patients, cerebral/renal and cerebral/cardiac being the most frequent combinations. Early recognition of patients developing organ damage with MRI should be further studied regarding treatment outcome since this may select a target population needing more intensive treatment.