Role of cardiovascular magnetic resonance in the guidelines of the European Society of Cardiology

BACKGROUND: Despite common enthusiasm for cardiovascular magnetic resonance (CMR), its application in Europe is quite diverse. Restrictions are attributed to a number of factors, like limited access, deficits in training, and incomplete reimbursement. Aim of this study is to perform a systematic summary of the representation of CMR in the guidelines of the European Society of Cardiology (ESC). METHODS: Twenty-nine ESC guidelines were screened for the terms "magnetic", "MRI", "CMR", "MR" and "imaging". As 3 topics were published twice (endocarditis, pulmonary hypertension, NSTEMI), 26 guidelines were finally included. MRI in the context of non-cardiovascular examinations was not recognized. The main CMR-related conclusions and, if available, the level of evidence and the class of recommendation were extracted. RESULTS: Fourteen of the 26 guidelines (53.8 %) contain specific recommendations regarding the use of CMR. Nine guidelines (34.6 %) mention CMR in the text, and 3 (11.5 %) do not mention CMR. The 14 guidelines with recommendations regarding the use of CMR contain 39 class-I recommendations, 12 class-IIa recommendations, 10 class-IIb recommendations and 2 class-III recommendations. Most of the recommendations have evidence level C (41/63; 65.1 %), followed by level B (16/63; 25.4 %) and level A (6/63; 9.5 %). The four guidelines, which absolutely contained most recommendations for CMR, were stable coronary artery disease (n = 14), aortic diseases (n = 9), HCM (n = 7) and myocardial revascularization (n = 7). CONCLUSIONS: CMR is represented in the majority of the ESC guidelines. They contain many recommendations in favour of the use of CMR in specific scenarios. Issues regarding access, training and reimbursement have to be solved to offer CMR to patients in accordance with the ESC guidelines

An environmental control box for serial crystallography enables multi-dimensional experiments

We present a new environmental enclosure for fixed-target, serial crystallography enabling full control of both the temperature and humidity. While maintaining the relative humidity to within a percent, this enclosure provides access to X-ray diffraction experiments in a wide temperature range from below 10 °C to above 80 °C. Coupled with the LAMA method, time-resolved serial crystallography experiments can now be carried out at truly physiological temperatures, providing fundamentally new insight into protein function. Using the hyperthermophile enzyme xylose isomerase, we demonstrate changes in the electron density as a function of increasing temperature and time. This method provides the necessary tools to successfully carry out multi-dimensional serial crystallography

Native myocardial T1 time can predict development of subsequent anthracycline-induced cardiomyopathy

Aims: This study aims to assess subclinical changes in functional and morphological myocardial magnetic resonance parameters very early into an anthracycline treatment, which may predict subsequent development of anthracycline-induced cardiomyopathy (aCMP). Methods and results: Thirty sarcoma patients with planned anthracycline-based chemotherapy (360-400 mg/m doxorubicin-equivalent) were recruited. Median treatment time was 19.1 ± 2.1 weeks. Enrolled individuals received three cardiovascular magnetic resonance studies (before treatment, 48 h after first anthracycline treatment, and upon completion of treatment). Native T1 mapping (modified Look-Locker inversion recovery 5s(3s)3s), T2 mapping, and extracellular volume maps were acquired in addition to a conventional cardiovascular magnetic resonance with steady-state free precession cine imaging at 1.5 T. Patients were given 0.2 mmol/kg gadoteridol for extracellular volume quantification and late gadolinium enhancement imaging. Development of relevant aCMP was defined as drop of left ventricular ejection fraction (LVEF) by >10%. For analysis, 23 complete data sets were available. Nine patients developed aCMP with LVEF reduction >10% until end of chemotherapy. Baseline LVEF was not different between patients with and without subsequent aCMP. When assessed 48 h after first dose of antracyclines, patients with subsequent aCMP had significantly lower native myocardial T1 times compared with before therapy (1002.0 ± 37.9 vs. 956.5 ± 29.2 ms, P  0.05). Patients with aCMP had decreased left ventricular mass upon completion of therapy (86.9 ± 24.5 vs. 81.1 ± 22.3 g; P = 0.02), while patients without aCMP did not show a change in left ventricular mass (81.8 ± 21.0 vs. 79.2 ± 18.1 g; P > 0.05). No patient developed new myocardial scars or compact myocardial fibrosis under chemotherapy. Conclusions: Early decrease of T1 times 48 h after first treatment with anthracyclines can predict the development of subsequent aCMP after completion of chemotherapy

Markov state modeling reveals competing collective hydrogen bond rearrangements in liquid water

We construct a Markov state model for the dynamic rearrangement of the local hydrogen bond network in liquid water. The model is based on trajectories from classical molecular dynamics simulations and accounts for the dynamics of relative angular and separation coordinates of water molecules. We analyze first the conformational subspace of three water molecules and find five well separated dynamic modes with reaction times in the 2 - 5 ps range, which correspond to different interchanges of hydrogen bond donor and acceptors, followed by an entire continuum spectrum of modes. We then analyze the switching of one hydrogen bond between two water molecules and derive the complete transition network. The most probable pathway corresponds to a direct switch without an intermediate, in agreement with previous studies. However, a considerable fraction of paths proceeds along different intermediate states that involve alternative hydrogen bonds or unbound states

Cardiovascular magnetic resonance in the guidelines of the European Society of Cardiology: a comprehensive summary and update

BACKGROUND: Cardiovascular magnetic resonance (CMR) has been established as a valuable tool in clinical and scientific cardiology. This study summarizes the current evidence and role of CMR in the guidelines of the European Society of Cardiology (ESC) and is an update of a former guideline analysis. METHODS: Since the last guideline analysis performed in 2015, 28 new ESC guideline documents have been published. Twenty-seven ESC practice guidelines are currently in use. They were screened regarding CMR in the text, tables and figures. The main CMR-related sentences and recommendations were extracted. RESULTS: Nineteen of the 27 guidelines (70.4%) contain relevant text passages regarding CMR in the text and include 92 specific recommendations regarding the use of CMR. Seven guidelines (25.9%) mention CMR in the text, and 1 (3.7%, dyslipidemia) does not mention CMR. The 19 guidelines with recommendations regarding the use of CMR contain 40 class-I recommendations (43.5%), 28 class-IIa recommendations (30.4%), 19 class-IIb recommendations (20.7%) and 5 class-III recommendations (5.4%). Most of the recommendations have evidence level C (56/92; 60.9%), followed by level B (34/92; 37.0%) and level A (2/92; 2.2%). Twenty-one recommendations refer to the field of cardiomyopathies, 21 recommendations to stress perfusion imaging, 20 recommendations to vascular assessment, 12 to myocardial tissue characterization in general, 8 to left and right ventricular function assessment, 5 to the pericardium and 5 to myocarditis. CONCLUSIONS: CMR is integral part of the majority of the ESC guidelines. Its representation in the guidelines has increased since the last analysis from 2015, now comprising 92 instead of formerly 63 specific recommendations. To enable patient management in accordance to the ESC guidelines, CMR must become more widely available

Variability and homogeneity of cardiovascular magnetic resonance myocardial T2-mapping in volunteers compared to patients with edema

BACKGROUND: The aim of the study was to test the reproducibility and variability of myocardial T2 mapping in relation to sequence type and spatial orientation in a large group of healthy volunteers. For control T2 mapping was also applied in patients with true edema. Cardiovascular magnetic resonance (CMR) T2-mapping has potential for the detection and quantification of myocardial edema. Clinical experience is limited so far. The variability and potential pitfalls in broad application are unknown. METHODS: Healthy volunteers (n = 73, 35 +/- 13 years) and patients with edema (n = 28, 55 +/- 17 years) underwent CMR at 1.5 T. Steady state free precession (SSFP) cine loops and T2-weighted spin echo images were obtained. In patients, additionally late gadolinium enhancement images were acquired. We obtained T2 maps in midventricular short axis (SAX) and four-chamber view (4CV) based on images with T2 preparation times of 0, 24, 55 ms and compared fast low angle shot (FLASH) and SSFP readout. 10 volunteers were scanned twice on separate days. Two observers analysed segmental and global T2 per slice. RESULTS: In volunteers global myocardial T2 systematically differed depending on image orientation and sequence (FLASH 52 +/- 5 vs. SSFP 55 +/- 5 ms in SAX and 57 +/- 6 vs. 59 +/- 6 ms in 4CV; p /= 70 ms. Mean intraobserver variability was 1.07 +/- 1.03 ms (r = 0.94); interobserver variability was 1.6 +/- 1.5 ms (r = 0.87). The coefficient of variation for repeated scans was 7.6% for SAX and 6.6% for 4CV. Mapping revealed focally increased T2 (73 +/- 9 vs. 51 +/- 3 ms in remote myocardium; p < 0.0001) in all patients with edema. CONCLUSIONS: Myocardial T2 mapping is technically feasible and highly reproducible. It can detect focal edema und differentiate it from normal myocardium. Increased T2 was found in some volunteers most likely due to partial volume and residual motion

Prospective, randomized comparison of gadopentetate and gadobutrol to assess chronic myocardial infarction applying cardiovascular magnetic resonance

BACKGROUND: We hypothesized that the contrast medium gadobutrol is not inferior compared to Gd-DTPA in identifying and quantifying ischemic late gadolinium enhancement (LGE), even by using a lower dose. METHODS: We prospectively enrolled 30 patients with chronic myocardial infarction as visualized by LGE during clinical routine scan at 1.5 T with 0.20 mmol/kg Gd-DTPA. Participants were randomized to either 0.15 mmol/kg gadobutrol (group A) or 0.10 mmol/kg gadobutrol (group B). CMR protocol was identical in both exams. LGE was quantified using a semiautomatic approach. Signal intensities of scar, remote myocardium, blood and air were measured. Signal to noise (SNR) and contrast to noise ratios (CNR) were calculated. RESULTS: Signal intensities were not different between Gd-DTPA and gadobutrol in group A, whereas significant differences were detected in group B. SNR of injured myocardium (53.5+/-21.4 vs. 30.1+/-10.4, p = 0.0001) and CNR between injured and remote myocardium (50.3+/-20.3 vs. 27.3+/-9.3, p < 0.0001) were lower in gadobutrol. Infarct size was lower in both gadobutrol groups compared to Gd-DTPA (group A: 16.8+/-10.2 g vs. 12.8+/-6.8 g, p = 0.03; group B: 18.6+/-12.0 g vs. 14.0+/-9.9 g, p = 0.0016). CONCLUSIONS: Taking application of 0.2 mmol/kg Gd-DTPA as the reference, the delineation of infarct scar was similar with 0.15 mmol/kg gadobutrol, whereas the use 0.10 mmol/kg gadobutrol led to reduced tissue contrast. TRIAL REGISTRATION: The study had been registered under EudraCT Number: 2010-020775-22 . Registration date: 2010.08.10

Myocardial T(1) and T(2) mapping at 3 T: reference values, influencing factors and implications

BACKGROUND: Myocardial T1 and T2 mapping using cardiovascular magnetic resonance (CMR) are promising to improve tissue characterization and early disease detection. This study aimed at analyzing the feasibility of T1 and T2 mapping at 3 T and providing reference values. METHODS: Sixty healthy volunteers (30 males/females, each 20 from 20--39 years, 40--59 years, 60--80 years) underwent left-ventricular T1 and T2 mapping in 3 short-axis slices at 3 T. For T2 mapping, 3 single-shot steady-state free precession (SSFP) images with different T2 preparation times were acquired. For T1 mapping, modified Look-Locker inversion recovery technique with 11 single shot SSFP images was used before and after injection of gadolinium contrast. T1 and T2 relaxation times were quantified for each slice and each myocardial segment. RESULTS: Mean T2 and T1 (pre-/post-contrast) times were: 44.1 ms/1157.1 ms/427.3 ms (base), 45.1 ms/1158.7 ms/411.2 ms (middle), 46.9 ms/1180.6 ms/399.7 ms (apex). T2 and pre-contrast T1 increased from base to apex, post-contrast T1 decreased. Relevant inter-subject variability was apparent (scatter factor 1.08/1.05/1.11 for T2/pre-contrast T1/post-contrast T1). T2 and post-contrast T1 were influenced by heart rate (p < 0.0001, p = 0.0020), pre-contrast T1 by age (p < 0.0001). Inter- and intra-observer agreement of T2 (r = 0.95; r = 0.95) and T1 (r = 0.91; r = 0.93) were high. T2 maps: 97.7% of all segments were diagnostic and 2.3% were excluded (susceptibility artifact). T1 maps (pre-/post-contrast): 91.6%/93.9% were diagnostic, 8.4%/6.1% were excluded (predominantly susceptibility artifact 7.7%/3.2%). CONCLUSIONS: Myocardial T2 and T1 reference values for the specific CMR setting are provided. The diagnostic impact of the high inter-subject variability of T2 and T1 relaxation times requires further investigation