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Patient-based real-time quality control (PBRTQC) is a laboratory tool for monitoring the performance of the testing process. It includes well-established procedures like Bull’s algorithm, average of nomals, moving median, moving average (MA) and exponentially (weighted) MAs. Following the setup and optimization processes, a key step prior to the routine implementation of PBRTQC is the verification and documentation of the performance of the PBRTQC as part of the laboratory quality system. This verification process should provide a realistic representation of the performance of the PBRTQC in the environment it is being implemented in, to allow proper risk assessment by laboratory practitioners. This document focuses on the recommendation on performance verification of PBRTQC prior to implementation.

For many years the concept of patient-based quality control (QC) has been discussed and implemented in hematology laboratories; however, the techniques have not been widely implemented in clinical chemistry. This is mainly because of the complexity of this form of QC, as it needs to be optimized for each population and often for each analyte. However, the clear advantages of this form of QC, together with the ongoing realization of the shortcomings of “conventional” QC, have driven a need to provide guidance to laboratories to assist in deploying patient-based QC. This overview describes the components of a patient-based QC system (calculation algorithm, block size, truncation limits, control limits) and the relationship of these to the analyte being controlled. We also discuss the need for patient-based QC system optimization using patient data from the individual testing laboratory to reliably detect systematic errors while ensuring that there are few false alarms. The term patient-based real-time quality control covers many activities that use data from patient samples to detect analytical errors. These activities include the monitoring of patient population parameters such as the mean or median analyte value or using single within-patient changes such as the delta check. In this report, we will restrict the discussion to population-based parameters. This overview is intended to serve as a guide for the implementation of a patient-based QC system. The report does not cover the clinical evaluation of the population.

Background: Diagnosis of cardiac involvement in amyloid A (AA) amyloidosis is challenging since AA amyloidosis is a rare disease and cardiac involvement even less frequent. The diagnostic yield of currently available non-invasive imaging methods is not well-studied and rather limited, and invasive endomyocardial biopsy (EMB) is rarely performed due to the potential risk of this procedure. Cardiovascular magnetic resonance (CMR)-based myocardial tissue characterization by late-gadolinium-enhancement (LGE) imaging and novel-mapping approaches may increase the diagnostic yield in AA amyloidosis.Methods: Two patients with AA amyloidosis in whom cardiac involvement was suspected based on CMR findings and subsequently proven by biopsy work-up are presented. CMR studies were performed on a 1.5-T system and comprised a cine steady-state free precession pulse sequence for ventricular function and a late-gadolinium-enhancement (LGE) sequence for detection of myocardial pathology. Moreover, a modified Look-Locker inversion recovery (MOLLI) T1-mapping sequence was applied in basal, mid and apical short-axes prior to contrast agent administration and ~20 min thereafter to determine native T1 and ECV values.Results: Both patients showed slightly dilated left ventricles (LV) with mild to moderate LV hypertrophy and preserved systolic function. Only a very subtle pattern of LGE was observed in both patients with AA amyloidosis. However, markedly elevated native T1 (max. 1,108 and 1,112 ms, respectively) and extracellular volume fraction (ECV) values (max. 39 and 48%, respectively) were measured in the myocardium suggesting the presence of cardiac involvement - with subsequent EMB-based proof of AA amyloidosis.Conclusion: We recommend a multi-parametric CMR approach in patients with AA amyloidosis comprising both LGE-based contrast-imaging and T1-mapping-based ECV measurement of the myocardium for non-invasive work-up of suspected cardiac involvement. The respective CMR findings may be used as gatekeeper for additional invasive procedures (such as EMB) and as a non-invasive monitoring tool regarding assessment and modification of ongoing treatments.

The possibilities of cardiovascular magnetic resonance (CMR) imaging for myocardial tissue characterization and catheter ablation guidance are accompanied by some fictional concepts. In this review, we present the available facts about CMR-guided catheter ablation procedures as well as promising, however unproven, theoretical concepts. CMR promises to visualize the respective arrhythmogenic substrate and may thereby make it more localizable for electrophysiology (EP)-based ablation. Robust CMR imaging is challenged by motion of the heart resulting from cardiac and respiratory cycles. In contrast to conventional "passive" tracking of the catheter tip by real-time CMR, novel approaches based on "active" tracking are performed by integrating microcoils into the catheter tip that send a receiver signal. Several experimental and clinical studies were already performed based on real-time CMR for catheter ablation of atrial and ventricular arrhythmias. Importantly, successful ablation of the cavotricuspid isthmus was already performed in patients with typical atrial flutter. However, a complete EP procedure with real-time CMR-guided transseptal puncture and subsequent pulmonary vein isolation has not been shown so far in patients with atrial fibrillation. Moreover, real-time CMR-guided EP for ventricular tachycardia ablation was only performed in animal models using a transseptal, retrograde, or epicardial access-but not in humans. Essential improvements within the next few years regarding basic technical requirements, such as higher spatial and temporal resolution of real-time CMR imaging as well as clinically approved cardiac magnetic resonance-conditional defibrillators, are ultimately required-but can also be expected-and will move this field forward.

In an increasingly interconnected health care system, laboratory medicine can facilitate diagnosis and treatment of patients effectively. This article describes necessary changes and points to potential challenges on a technical, content, and organizational level. As a technical precondition, electronic laboratory reports have to become machine-readable and interpretable. Terminologies such as Logical Observation Identifiers Names and Codes (LOINC), Nomenclature for Properties and Units (NPU), Unified Code for Units of Measure (UCUM), and SNOMED-CT can lead to the necessary semantic interoperability. Even if only single “atomized” results of the whole report are extracted, the necessary information for correct interpretation must be available. Therefore, interpretive comments, e.g., concerns about an increased measurement uncertainty must be electronically attached to every affected measurement result. Standardization of laboratory analyses with traceable standards and reference materials will enable knowledge transfer and safe interpretation of laboratory analyses from multiple laboratories. In an interconnected health care system, laboratories should strive to transform themselves into a data hub that not only receives samples but also extensive information about the patient. On that basis, they can return measurement results enriched with high-quality interpretive comments tailored to the individual patient and unlock the full potential of laboratory medicine.

Introduction Cardiovascular mortality is significantly increased in kidney failure with replacement therapy (KFRT) patients, which is partly mediated by enhanced vascular calcification. Magnesium appears to have anticalcifying capabilities, and hypomagnesemia has been associated with increased mortality in KFRT patients. Ionized magnesium represents the biologically and physiologically active form. As serum ionized magnesium (Mgion ) is difficult to assess in clinical routine estimating equations derived from routinely assessed laboratory parameters could facilitate medical treatment. Methods We developed equations to estimate serum Mgion using linear regression analysis in 191 hemodialysis (HD) patients. Reference test was measured ionized magnesium (Mgion ). As index tests, we chose estimated Mgion using total magnesium (Mgtot ) and other laboratory and demographic variable candidates. Equations were internally validated, using 749 subsequent Mgion measurements. Findings The median patient age was 65 years, 67.5% of the patients were male. Median (interquartile range [IQR]) measured Mgion was 0.64 [0.57, 0.72] mmol/L, 11 (6%) patients were hypo- (i.e., 0.60 mmol/L). The final equation at the end of the development process included Mgtot , serum ionized, and total calcium concentrations. In the validation dataset, bias (i.e., median difference between measured and estimated Mgion , -0.017 [-0.020, -0.014] mmol/L) and precision (i.e., IQR of bias 0.043 [0.039, 0.047] mmol/L) were small, 90% [88, 93] of estimated values were ±10% of measured values. The equation detected normomagnesemia with overall good diagnostic accuracy (area under the receiver-operating curve 0.91 [0.89, 0.93]). Discussion Mgion can be estimated from equations containing routinely assessed laboratory variables with high accuracy and good overall performance. These equations might simplify the assessment of ionized magnesium levels in the individual hemodialysis patients and help the treating physician to guide the overall treatment.

Background Cardiac amyloidosis (CA) is an infiltrative disease that is characterized by accumulation of amyloid deposits in the interstitium of the myocardium. In contrast, hypertrophic cardiomyopathy (HCM) is caused by a disorganized arrangement of myocyte hypertrophy as well as expanded extracellular matrix, composed of interstitial and replacement fibrosis. Purpose A diagnostic algorithm based on (native) T1-mapping using cardiovascular magnetic resonance (CMR) was suggested in a recent study for the diagnosis of CA: A native T1 1,164ms showed a 98% positive predictive value (PPV) for the presence of CA. In the present study, we critically addressed the calculation of such cut-off values considering possible differences in the composition of the control group. Methods N=30 patients with CA, N=20 patients with HCM and N=15 healthy controls without relevant cardiac disease underwent dedicated CMR studies on a 1.5-T MR scanner. The CMR protocol comprised standard sequences for cine-imaging, native and post-contrast MOLLI-based T1-mapping and late-gadolinium-enhancement (LGE). ECV measurements were based on pre- and post-contrast T1-mapping images. Results Native T1 and ECV were significantly increased in CA compared to HCM and receiver operating characteristic (ROC) analyses revealed an area-under-the-curve (AUC) = 0.984 for native T1 (p Conclusion Cut-off values for native T1 or ECV derived from ROC analyses (in a specific group of study patients) for ruling in or out the presence of CA are – amongst others - determined by the native T1 and ECV values of the respective “control group”. A different composition of the control group (e.g. HCM patients vs. healthy volunteers) will result in different cut-off values. Hence, previously suggested cut-off values obtained in single center studies need to be considered carefully – with a special attention to the control group of the underlying study – and should not be transferred to other centers carelessly. Funding Acknowledgement Type of funding source: None

Objectives Therapeutic drug monitoring (TDM) plays a crucial role in personalized medicine. It helps clinicians to tailor drug dosage for optimized therapy through understanding the underlying complex pharmacokinetics and pharmacodynamics. Conventional, non-continuous TDM fails to provide real-time information, which is particularly important for the initial phase of immunosuppressant therapy, e.g., with cyclosporine (CsA) and mycophenolic acid (MPA). Methods We analyzed the time course over 8 h of total and free of immunosuppressive drug (CsA and MPA) concentrations measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in 16 kidney transplant patients. Besides repeated blood sampling, intravenous microdialysis was used for continuous sampling. Free drug concentrations were determined from ultracentrifuged EDTA-plasma (UC) and compared with the drug concentrations in the respective microdialysate (µD). µDs were additionally analyzed for free CsA using a novel immunosensor chip integrated into a fluorescence detection platform. The potential of microdialysis coupled with an optical immunosensor for the TDM of immunosuppressants was assessed. Results Using LC-MS/MS, the free concentrations of CsA (fCsA) and MPA (fMPA) were detectable and the time courses of total and free CsA comparable. fCsA and fMPA and area-under-the-curves (AUCs) in µDs correlated well with those determined in UCs (r≥0.79 and r≥0.88, respectively). Moreover, fCsA in µDs measured with the immunosensor correlated clearly with those determined by LC-MS/MS (r=0.82). Conclusions The new microdialysis-supported immunosensor allows real-time analysis of immunosuppressants and tailor-made dosing according to the AUC concept. It readily lends itself to future applications as minimally invasive and continuous near-patient TDM.

The quest to use patient results as quality control for routine clinical chemistry testing has long been driven by issues of the unavailability and cost of suitable quality control material and the matrix effects of synthetic material. Hematology laboratories were early adopters of average of normals techniques, primarily because of the difficulty in acquiring appropriate, stable quality control material, while in the chemistry laboratories, the perceived advantages and availability of synthetic material outweighed the disadvantages. However, the increasing volume of testing in clinical chemistry plus the capability of computer systems to deal with large and complex calculations has now made the use of patient-based quality control algorithms feasible. The desire to use patient-based quality control is also driven by increasing awareness that common quality control rules and frequency of analysis may fail to detect clinically significant assay biases. The non-commutability of quality control material has also become a problem as laboratories seek to harmonize results across regions and indeed globally. This review describes the history of patient-based quality control in clinical chemistry, summarizes the various approaches that can be implemented by laboratory professionals, and discusses how patient-based quality control can be integrated with traditional quality control techniques.

Background Cardiovascular magnetic resonance (CMR) studies in patients with implanted cardioverter/defibrillators (ICD) are increasingly required in daily clinical practice. However, the clinical experience regarding the feasibility as well as clinical value of CMR studies in patients with subcutaneous ICD (S-ICD) is still limited. Besides safety issues, image quality and analysis can be impaired primarily due the presence of image artefacts associated with the generator. Methods Twenty-three patients with an implanted S-ICD (EMBLEM, Boston Scientific, Marlborough, Massachusetts, USA; MR-conditional) with suspected cardiomyopathy and/or myocarditis underwent multi-parametric CMR imaging. Studies were performed on a 1.5 T CMR scanner after device interrogation and comprised standard a) balanced steady state free precession cine, b) T2 weighted-edema, c) velocity-encoded cine flow, d) myocardial perfusion, e) late-gadolinium-enhancement (LGE)-imaging and f) 3D-CMR angiography of the aorta. In case of substantial artefacts, alternative CMR techniques such as spoiled gradient-echo cine-sequences and wide-band inversion-recovery LGE (wb-LGE) sequences were applied. Results Successful CMR studies could be performed in all patients without any case of unexpected early termination or relevant technical complication other than permanent loss of the S-ICD system beeper volume in 52% of our patients. Assessment of cine-CMR images was predominantly impaired in the left ventricular (LV) anterior, lateral and inferior wall segments and a switch to spoiled gradient echo-based cine-CMR allowed an accurate assessment of cine-images in N = 17 (74%) patients with only limited artefacts. Hyperintensity artefacts in conventional LGE-images were predominantly observed in the LV anterior, lateral and inferior wall segments and image optimisation by use of the wb-LGE was helpful in 15 (65%) cases. Aortic flow measurements and 3D-CMR angiography were assessable in all patients Perfusion imaging artefacts precluded a meaningful assessment in at least one half of the patients. A benefit in clinical-decision making was documented in 17 (74%) patients in the present study. Conclusion Safe 1.5 T CMR imaging was possible in all patients with an S-ICD, though the majority had permanent loss of the S-ICD beeper volume. Achieving good image quality may be challenging in some patients - particularly for perfusion imaging. Using spoiled gradient echo-based cine-sequences and wb-LGE sequences may help to reduce the extent of artefacts, thereby allowing accurate cardiac assessment. Thus, 1.5 T CMR studies should not be withhold in patients with S-ICD for safety concerns and/or fear of extensive imaging artefacts precluding successful image analysis.

Background Terminologies facilitate data exchange and enable laboratories to assist in patient care even if complex treatment pathways involve multiple stakeholders. This paper examines the three common terminologies Nomenclature for Properties and Units (NPU), Logical Observation Identifiers Names and Codes (LOINC), and SNOMED Clinical Terms (SNOMED CT). Methods The potential of each terminology to encode five exemplary laboratory results is assessed. The terminologies are evaluated according to scope, correctness, formal representations, and ease of use. Results NPU is based on metrological concepts with strict rules regarding the coding of the measurand and the result value. Clinically equivalent results are regularly mapped to the same code but there is little support to differentiate results from non-standardized measurements. LOINC encodes analyses as offered by the laboratory. Its large number of entries allows different mappings for the same analysis. SNOMED CT contains few analyses natively, but its formal composition mechanism allows representing measurements by post-coordinated expressions that are equivalent to LOINC codes. SNOMED CT’s strength lies in its support of many non-numerical result values. Implicit code hierarchies exist in NPU and LOINC. SNOMED CT has explicit, elaborate axioms that elucidate the meaning of its content. Its complexity and its license conditions, however, impede a more widespread use. Interpretive comments, a crucial part of laboratory results, are still difficult to encode with any of the terminologies. Conclusions All three terminologies have distinct potentials and limitations, but the approximation of SNOMED CT and LOINC suggests using them together. Terminologies need to be expanded to also cover interpretive comments.

Background:Determination of blood glucose concentration is one of the most important measurements in clinical chemistry worldwide. Analyzers in central laboratories (CL) and point-of-care tests (POCT) are both frequently used. In Germany, regular participation in external quality assessment (EQA) schemes is mandatory for laboratories performing glucose testing.Methods:Glucose testing data from the two German EQAs “Reference Institute for Bioanalytics” (RfB) and “INSTAND – Gesellschaft zur Förderung der Qualitätssicherung in medizinischen Laboratorien” (Instand) were analyzed from 2012 to 2016. Multivariable odds ratios (OR) for the probability to reach a “good” result were calculated. Imprecision and bias were determined and clinical risk of measurement errors estimated.Results:The device employed was the most important variable required for a “good” performance in all EQAs. Additional participation in an EQA for CL automated analyzers improved performance in POCT EQAs. The reciprocal effect was less pronounced. New participants performed worse than experienced participants especially in CL EQAs. Imprecision was generally smaller for CL, but some POCT devices reached a comparable performance. Large lot-to-lot differences occurred in over 10% of analyzed cases. We propose the “bias budget” as a new metric to express the maximum allowable bias that still carries acceptable medical risk. Bias budgets were smallest and clinical risks of errors greatest in the low range of measurement 60–115 mg/dL (3.3–6.4 mmol/L) for most devices.Conclusions:EQAs help to maintain high analytical performances. They generate important data that serve as the foundation for learning and improvement in the laboratory healthcare system.

Zusammenfassung Die Arbeitsgruppe POCT der Deutschen Gesellschaft für Klinische Chemie und Laboratoriumsmedizin (DGKL) hat vom 13. bis 15. März 2017 das dritte Münchner Symposium zum Thema „Weiterentwicklung der patientennahen Sofortdiagnostik in unterschiedlichen klinischen Anwendungsbereichen“ organisiert. Unter der Kongressleitung von Prof. Dr. Peter B. Luppa, TU München wurden die Themenschwerpunkte von 43 Vortragenden behandelt. Dabei wurden insgesamt 9 Sitzungen von den Mitgliedern der Arbeitsgruppe POCT geleitet. Die Kongresssprachen waren Deutsch und Englisch. Eine angeschlossene Industrieausstellung mit 29 IVD-Unternehmen zeigte die neuesten POCT-Analysengeräte. Erstmals fand zudem eine ePosterausstellung mit 24 Postern in zwei eigenen Sessions statt. Dabei lagen die Poster elektronisch vor, der vorstellende Autor konnte es an einem speziellen Monitor allen Teilnehmern wie eine Bilderpräsentation vorführen. Neu war auch die Vergabe von 4 Vortrags- und 2 Posterpreisen.

Insufficient operator training has been identified as an underlying root cause for many errors of point-of-care testing. However, while the need for operator training is beyond doubt, the practical solutions on how to train operators remain challenging. Therefore a multidisciplinary team of experts created the application guide VDE-AR-E 2411-2-101 “Schulung professioneller Anwender von patientennahen Tests” (Training of professional users of devices for near-patient testing). This work is based on the talk of Nicola Barabas during the POCT-Symposium in Munich 2017 and presents selected aspects of the application guide such as the role of the manufacturer, the learning path, the selection of training topics, the train-the-trainer concept and e-learning.

BACKGROUNDIn clinical chemistry, quality control (QC) often relies on measurements of control samples, but limitations, such as a lack of commutability, compromise the ability of such measurements to detect out-of-control situations. Medians of patient results have also been used for QC purposes, but it may be difficult to distinguish changes observed in the patient population from analytical errors. This study aims to combine traditional control measurements and patient medians for facilitating detection of biases.METHODSThe software package “rSimLab” was developed to simulate measurements of 5 analytes. Internal QC measurements and patient medians were assessed for detecting impermissible biases. Various control rules combined these parameters. A Westgard-like algorithm was evaluated and new rules that aggregate Z-values of QC parameters were proposed.RESULTSMathematical approximations estimated the required sample size for calculating meaningful patient medians. The appropriate number was highly dependent on the ratio of the spread of sample values to their center. Instead of applying a threshold to each QC parameter separately like the Westgard algorithm, the proposed aggregation of Z-values averaged these parameters. This behavior was found beneficial, as a bias could affect QC parameters unequally, resulting in differences between their Z-transformed values. In our simulations, control rules tended to outperform the simple QC parameters they combined. The inclusion of patient medians substantially improved bias detection for some analytes.CONCLUSIONSPatient result medians can supplement traditional QC, and aggregations of Z-values are novel and beneficial tools for QC strategies to detect biases.

We study the importance of teacher subject knowledge for student performance in Sub-Saharan Africa using unique international assessment data for sixth-grade students and their teachers. To circumvent bias due to unobserved student heterogeneity, we exploit variation within students across math and reading. Teacher subject knowledge has a modest impact on student performance. Exploiting vast cross-country differences in economic development, we find that teacher knowledge is effective only in more developed African countries. Results are robust to adding teacher fixed effects and accounting for potential sorting based on subject-specific factors.

Cardiomyopathy, characterized by non-ischemic myocardial fibrosis of the left ventricle (LV) with a myocarditis-like pattern, is a frequent cause of morbidity and mortality in patients with Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD)—as it leads to systolic dysfunction

Following a landmark ruling by the Constitutional Court in 2005, more than half of Germany's universities started charging tuition fees, which also applied to incumbent students. We exploit this unusual lack of grandfathering together with register data covering the universe of students to show that tuition fees increased degree completion among incumbent students. Investigating mechanisms, we do not find that educational quality changed but that incumbent students raised their study effort. In line with previous international evidence, we also find that tuition fees decreased university enrollment among high school graduates. Combining our results, we show that tuition fees did not change overall educational attainment much because the positive effect on degree completion offset the negative effect on enrollment. We conclude by discussing policies to increase overall attainment, which take into account the opposing effects of fees around the zero-price margin.

Following a landmark ruling by the Constitutional Court in 2005, more than half of Germany’s universities started charging tuition fees, which also applied to incumbent students. We exploit this unusual lack of grandfathering together with register data covering the universe of students to show that tuition fees increased degree completion among incumbent students. Investigating mechanisms, we do not find that educational quality changed but that incumbent students raised their study effort. In line with previous international evidence, we also find that tuition fees decreased university enrollment among high school graduates. Combining our results, we show that tuition fees did not change overall educational attainment much because the positive effect on degree completion offset the negative effect on enrollment. We conclude by discussing policies to increase overall attainment, which take into account the opposing effects of fees around the zero-price margin.

We revisit and substantially extend the evidence on the importance of instruction time for student achievement on international assessments. We first successfully replicate the estimate of a positive effect of weekly instruction time in the seminal paper by Lavy (Economic Journal, 125, F397-F424) in a narrow sense. We then extend the analysis to data from other international student assessments and find effects that are consistently smaller in magnitude. We provide suggestive evidence that this divergence is partly due to different measurement of instruction time in the data used in the original paper. Our results suggest that differences in instruction time play a less important role than previously thought for explaining international gaps in student achievement.

I study how motivation shapes own and peers' educational success. Using data from Project STAR, I find that academic motivation in early elementary school, as measured by a standardized psychological test, predicts contemporaneous and future test scores, high school GPA, and college-test taking over and above cognitive skills. Exploiting random assignment of students to classes, I find that exposure to motivated classmates causally affects contemporaneous reading achievement, a peer effect that operates over and above spillovers from classmates' past achievement and socio-demographic composition. However, peer motivation does not affect longer-term educational success, likely because it does not change own motivation.

Interventional magnetic resonance imaging (MRI) procedures promise to open-up new vistas regarding clinically relevant diagnostic and/or therapeutic procedures in the field of cardiology. However, a number of major limitations and challenges regarding interventional cardiovascular magnetic resonance (CMR) procedures still delay their translation from pre-clinical studies to human application. A CMR-conditional cardiac phantom was constructed using MR-safe or -conditional materials only that is based on a unique modular composition allowing quick replacement of individual components. A maximal flow of 76 ml/sec in the aorta and 111 ml/sec in the pulmonary artery were measured, whereas the maximal flow velocity was 56 cm/sec and 89 cm/sec, respectively. A conventional wedge-pressure catheter was advanced over a MRI-conditional guidewire into the right ventricle and thereafter positioned in the pulmonary artery. Pulmonary artery pressure was measured, obtaining the following values for our cardiac phantom: max/min/mean = 16/10/12 mmHg. The presented CMR-conditional cardiac phantom is the first of its kind that does not only mimic cardiac mechanics with adjustable fluid pressure in a four chamber setup that is closely adapted to that of the human heart, but also enables introduction and testing of interventional tools such as guidewires and catheters.

Background MELAS syndrome (mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes) is a rare clinical subtype of mitochondrial myopathy. Cardiovascular magnetic resonance (CMR) images of MELAS-patients at an advanced state of the disease often show characteristic patterns: septal pronounced left ventricular (LV) hypertrophy and distinct focal myocardial scars in late-gadolinium-enhancement (LGE) images. This specific pattern is different from those seen in patients with hypertrophic cardiomyopathy (HCM) due to sarcomere protein mutations. Besides LGE imaging another method for the assessment of myocardial integrity, T1-mapping, has been established recently. This is the first study comparing native and enhanced T1-mapping (T1-na/en) as well as extracellular volume (ECV) values in HCM and MELAS. Methods 12 patients with confirmed MELAS syndrome at different states of the disease, 13 HCM patients and 15 controls were included. All CMR studies were performed on a 1.5T MR scanner (Ingenia, Philips) using bSSFP cine sequences for the assessment of LV-function and MOLLI sequences for T1-na/en mapping. 15min after IV injection of 0.1mmol/kg BW Gadobutrol for LGE imaging, T1-en maps were acquired. For comparison of groups T1-na/en and ECV values in a basal short axis slice were used. Results Median and interquartile ranges of LV function, T1 and ECV are shown in the table. There was no difference in LV ejection fraction (LVEF) between the groups, but end-diastolic LV-mass was increased in HCM- and MELAS-patients vs. controls (p LV-function and mapping parameters of compared groups LV-EF, % LV-EDV, ml/m2 LV-mass, g/m2 T1-na, ms T1-en, ms ECV, % MELAS 57 (44–63) 86 (81–122) 80 (50–131) 969 (940–1033) 409 (381–465) 27 (24–35) HCM 60 (57–65) 50 (73–94) 94 (72–102) 1041 (1021–1074) 362 (346–430) 31 (28–36) Controls 61 (58–65) 72 (67–89) 53 (42–60) 937 (894–951) 464 (446–513) 26 (24–27) Conclusion Compared to healthy controls and HCM-patients, cardiac involvement in MELAS-patients is not only reliably visualized by conventional LGE imaging but also detected without the use of contrast agent by native T1-mapping. MELAS vs. HCM-patients show a different pattern of LGE and higher native T1 values, respectively.

Background Ebstein anomaly (EA) is a rare congenital heart disease characterized by an apically displaced tricuspid valve. It is associated with tricuspid valve regurgitation and right heart dilatation leading to significant morbidity. While echocardiography remains the mainstay of routine outpatient cardiac imaging, assessment of right ventricular (RV) anatomy and function is still challenging. Cardiovascular magnetic resonance imaging (CMR) has been shown to be of advantage in these patients being free from acoustic window limitations and offering superior volume quantification. In the present study, parameters obtained from cardiopulmonary exercise testing (CPET) were compared to conventional and novel CMR parameters in patients with EA. Methods In this prospective single centre study, N=17 patients with EA (mean age = 33.8±12.7yrs; N=10 females) underwent clinical assessment, CPET and multi-parametric CMR. Maximal work load (maxWL) and peak oxygen uptake (maxO2) were derived from CPET. CMR studies were performed on a 1.5-T Philips scanner and respective CMR parameters comprised a) anatomical, b) functional and c) myocardial deformation values of both ventricles. Results The majority of patients presented in NYHA class I or II (mean NYHA = 1.6±0.7) and with normal or mildly elevated NT-proBNP values (mean NT-proBNP = 189±158pg/ml). CPET-based maxWL was 147.14±55 watts and maxO2 19.32±5 ml/kg/min. CMR-based mean LVEF was 57.1±6.4% and RVEF was 46.5±11.1%, respectively. Deformation imaging revealed (amongst others) a LV global longitudinal strain (LV-gLS) of −13.7±3.0 and a RV global longitudinal strain (RV-gLS) of −14.7±5.0. Non-ischemic presence of late-gadolinium-enhancement was documented in 36% of our patients. Comprehensive correlation analysis revealed a substantial correlation a) between LV-gLS and NYHA class (r=0.64, p=0.01), but not between RV-gLS and NYHA class (r=0.19, p=0.46), b) between serum NT-proBNP levels and maxO2 (r=−0.53, p=0.03) as well as maxWL (r=−0.63, p=0.02), and c) between LV-EF and LV-gLS (r=−0.64, p=0.01). Conclusion Our preliminary data suggest that serum markers such as NT-proBNP and novel CMR parameters such as LV-gLS – but not RV-gLS - correlate with CPET-derived exercise parameters in patients with EA. The predictive value of these parameters regarding cardiac disease progression in EA has to be evaluated in future follow-up studies.