Die kardiovaskuläre Magnetresonanztomographie in der Diagnostik der Herzinsuffizienz mit erhaltener Ejektionsfraktion

Die Herzinsuffizienz ist eine der häufigsten Todesursachen in Deutschland. In mehr als 50% der Fälle liegt dabei eine Herzinsuffizienz mit erhaltener Pumpfunktion (HFpEF) vor. Innerhalb aktueller Leitlinien der Kardiologie gewinnt die kardiovaskuläre Magnetresonanztomographie (MRT) zunehmend an Bedeutung. In der Diagnostik der HFpEF spielt sie bisher jedoch eine untergeordnete Rolle. Grund dafür sind unter anderem lange Untersuchungszeiten, limitierende Untersuchungsbedingungen sowie fehlende, klinisch etablierte Parameter zur Beurteilung der diastolischen Funktion und entsprechende Referenzwerte. Ziel dieser Arbeit ist es, Parameter der kardiovaskulären MRT zu identifizieren, welche am besten zur Evaluierung der diastolischen Funktion geeignet sind und darüber hinaus schnellere Methoden zu etablieren, welche insbesondere auch eine Untersuchung schwer kranker Patientinnen und Patienten ermöglichen. Die diastolische Funktion von 50 Patientinnen und Patienten wurde anhand des echokardiographischen Verhältnisses aus E/E‘, des invasiv gemessenen, linksventrikulären enddiastolischen Drucks sowie des NT-proBNP- Serumspiegels (N- Terminal pro-brain Natriuretic Peptide) in normal, eingeschränkt und unklar eingeteilt. Anschließend wurden verschiedene MRT-Parameter zur Beurteilung linksventrikulärer Volumina, Funktion, Blutflussgeschwindigkeiten und intramyokardialer Deformierung hinsichtlich ihrer Übereinstimmung mit dieser Gruppeneinteilung analysiert (1). Bei 203 gesunden Probandeninnen und Probanden wurden unter Anwendung zeiteffizienter Routineprotokolle linksatriale Volumina analysiert, um Normwerte zu generieren. Diese wurden bezüglich einer Abhängigkeit von Alter, Geschlecht und Feldstärke untersucht (2). Darüber hinaus erfolgte der Vergleich zweier neuer, schneller Sequenzen zur Beurteilung myokardialer Fibrose mit einer Standardreferenzsequenz. Dafür wurden 312 Patientinnen und Patienten mit ischämischen und nicht-ischämischen Kardiomyopathien untersucht (3). Verminderte basolaterale Deformierungseigenschaften sowie eine linksatriale Dilatation stellten die besten Diskriminierungsparameter zwischen Patientinnen bzw. Patienten mit normaler und eingeschränkter diastolischer Funktion dar (1). Linksatriale Normwerte konnten bestimmt und eine altersabhängige Abnahme dieser Werte gezeigt werden. Geschlechtsabhängige Unterschiede waren nach Normierung auf Körperoberfläche oder Körperhöhe nicht mehr nachweisbar. Eine Abhängigkeit von der Feldstärke bestand nicht (2). Verglichen mit der Standardreferenzsequenz benötigten neue multi-slice Sequenzen signifikant weniger Zeit zur Datenaufnahme und zeigten äquivalente Ergebnisse in der Beurteilung myokardialen Narbengewebes. Zudem konnte selbst unter Arrhythmien und verminderter Atemhaltekapazität eine ausgezeichnete Bildqualität verzeichnet werden (3). Zusammenfassend können die Möglichkeit der Beurteilung der diastolischen Funktion und zeiteffizientere, Rhythmus- und Atemmuster-unabhängige Untersuchungsmethoden helfen, die kardiovaskuläre MRT als diagnostisches Mittel der HFpEF voranzubringen.Heart failure is one of the leading causes of death in Germany, while heart failure with preserved ejection fraction (HFpEF) is prevalent in more than 50% of affected patients. According to current cardiological guidelines cardiovascular magnetic resonance imaging (CMR) has become increasingly important. However, concerning the diagnosis of HFpEF CMR represents merely an adjunct. Long acquisition time, limiting examination conditions, a lack of valid clinical parameters to assess diastolic function and corresponding reference values are some of the reasons. Aim of this work is to identify the best CMR-parameters to evaluate diastolic function and furthermore to establish less time-consuming methods to especially be able to perform investigations in severely ill patients. Based on echocardiographic generated E/E’, invasively measured left ventricular enddiastolic pressure and serum level of N-terminal pro brain natriuretic peptide, diastolic function of a 50 patients’ cohort was graded in normal, impaired and uncertain. Different CMR-parameters for assessment of left ventricular volumes, function, blood flow velocities and intramyocardial deformation were quantified (1). 203 healthy volunteers were investigated to generate normal values of left atrial volumes using time efficient routine CMR-protocols. Dependence of sex, age and field strength was analysed (2). Furthermore, we compared the standard sequence for assessment of myocardial fibrosis with two new faster sequences. Therefor 312 patients with ischaemic and non-ischaemic cardiomyopathies were examined (3). Reduced basolateral deformation and left atrial dilatation showed best discrimination between patients with and without diastolic dysfunction (1). Left atrial reference values decreased with age. Sex-dependent differences disappeared after normalisation to body high or body surface area. Field strength did not show any influence (2). In comparison new multi-slice sequences showed equivalent results in assessment of myocardial scare to the reference sequence while data acquisition was significantly less time-consuming. Even in cases with arrhythmia or limited breathhold conditions, multislice sequences reached excellent image quality (2). In conclusion, the possibility to assess diastolic function as well as using time-efficient, rhythm- and breathhold-independent examination methods might help to integrate CMR as a diagnostic feature of HFpEF

Quantification of the left atrium applying cardiovascular magnetic resonance in clinical routine

Objectives: In recent years the impact of the left atrium (LA) has become more evident in different cardiovascular pathologies. We aim to provide LA parameters in healthy volunteers for cardiovascular magnetic resonance (CMR) using a fast approach. Design: We analyzed 203 healthy volunteers (mean age 44.6 years (y), range 19y-76y) at 1.5 and 3.0 Tesla (T) using steady-state free precession (SSFP) cine in routine long axis view. Left atrial enddiastolic volume (LA-EDV), endsystolic volume (LA-ESV), stroke volume (LA-SV) and ejection fraction (LA-EF) were quantified and indexed to body-surface-area (BSA). Dependency on age and sex was analyzed. Results: 21 subjects had to be excluded. In the remaining, there was no significant difference between 1.5 T and 3.0 T. Absolut LA-EDV and LA-ESV were larger in men than in women (LA-EDV: male 70±19ml vs. female 61±16ml (p=.001); LA-ESV: male 24±9ml vs. female 21±8ml (p=.01)). These differences disappeared after indexing to BSA (LA-EDV/BSA: male 34±10ml/m(2) vs. female 33±9ml/m(2) (p=.65) and LA-ESV/BSA: male 12±4ml/m2 vs. female 11±4ml/m2 (p=.71)). LA-EDV/BSA decreased with older age. Conclusions: Reference values for LA size and function based on a fast approach are provided. LA size decreases with older age. Normalization to body size overcomes sex-dependency. Reports should be related to body size

Assessment of diastolic dysfunction: comparison of different cardiovascular magnetic resonance techniques.

AIMS Heart failure with preserved ejection fraction is still a diagnostic and therapeutic challenge, and accurate non-invasive diagnosis of left ventricular (LV) diastolic dysfunction (DD) remains difficult. The current study aimed at identifying the most informative cardiovascular magnetic resonance (CMR) parameters for the assessment of LVDD. METHODS AND RESULTS We prospectively included 50 patients and classified them into three groups: with DD (DD+, n = 15), without (DD-, n = 26), and uncertain (DD±, n = 9). Diagnosis of DD was based on echocardiographic E/E', invasive LV end-diastolic pressure, and N-terminal pro-brain natriuretic peptide. CMR was performed at 1.5 T to assess LV and left atrial (LA) morphology, LV diastolic strain rate (SR) by tissue tracking and tagging, myocardial peak velocities by tissue phase mapping, and transmitral inflow profile using phase contrast techniques. Statistics were performed only on definitive DD+ and DD- (total number 41). DD+ showed enlarged LA with LA end-diastolic volume/height performing best to identify DD+ with a cut-off value of ≥0.52 mL/cm (sensitivity = 0.71, specificity = 0.84, and area under the receiver operating characteristic curve = 0.75). DD+ showed significantly reduced radial (inferolateral E peak: DD-: -14.5 ± 6.5%/s vs. DD+: -10.9 ± 5.9%/s, P = 0.04; anterolateral A peak: DD-: -4.2 ± 1.6%/s vs. DD+: -3.1 ± 1.4%/s, P = 0.04) and circumferential (inferolateral A peak: DD-: 3.8 ± 1.2%/s vs. DD+: 2.8 ± 0.8%/s, P = 0.007; anterolateral A peak: DD-: 3.5 ± 1.2%/s vs. DD+: 2.5 ± 0.8%/s, P = 0.048) SR in the basal lateral wall assessed by tissue tracking. In the same segments, DD+ showed lower peak myocardial velocity by tissue phase mapping (inferolateral radial peak: DD-: -3.6 ± 0.7 ms vs. DD+: -2.8 ± 1.0 ms, P = 0.017; anterolateral longitudinal peak: DD-: -5.0 ± 1.8 ms vs. DD+: -3.4 ± 1.4 ms, P = 0.006). Tagging revealed reduced global longitudinal SR in DD+ (DD-: 45.8 ± 12.0%/s vs. DD+: 34.8 ± 9.2%/s, P = 0.022). Global circumferential and radial SR by tissue tracking and tagging, LV morphology, and transmitral flow did not differ between DD+ and DD-. CONCLUSIONS Left atrial size and regional quantitative myocardial deformation applying CMR identified best patients with DD

Comparison of fast multi-slice and standard segmented techniques for detection of late gadolinium enhancement in ischemic and non-ischemic cardiomyopathy – a prospective clinical cardiovascular magnetic resonance trial

Abstract Background Segmented phase-sensitive inversion recovery (PSIR) cardiovascular magnetic resonance (CMR) sequences are reference standard for non-invasive evaluation of myocardial fibrosis using late gadolinium enhancement (LGE). Several multi-slice LGE sequences have been introduced for faster acquisition in patients with arrhythmia and insufficient breathhold capability. The aim of this study was to assess the accuracy of several multi-slice LGE sequences to detect and quantify myocardial fibrosis in patients with ischemic and non-ischemic myocardial disease. Methods Patients with known or suspected LGE due to chronic infarction, inflammatory myocardial disease and hypertrophic cardiomyopathy (HCM) were prospectively recruited. LGE images were acquired 10–20 min after administration of 0.2 mmol/kg gadolinium-based contrast agent. Three different LGE sequences were acquired: a segmented, single-slice/single-breath-hold fast low angle shot PSIR sequence (FLASH-PSIR), a multi-slice balanced steady-state free precession inversion recovery sequence (bSSFP-IR) and a multi-slice bSSFP-PSIR sequence during breathhold and free breathing. Image quality was evaluated with a 4-point scoring system. Contrast-to-noise ratios (CNR) and acquisition time were evaluated. LGE was quantitatively assessed using a semi-automated threshold method. Differences in size of fibrosis were analyzed using Bland-Altman analysis. Results Three hundred twelve patients were enrolled (n = 212 chronic infarction, n = 47 inflammatory myocardial disease, n = 53 HCM) Of which 201 patients (67,4%) had detectable LGE (n = 143 with chronic infarction, n = 27 with inflammatory heart disease and n = 31 with HCM). Image quality and CNR were best on multi-slice bSSFP-PSIR. Acquisition times were significantly shorter for all multi-slice sequences (bSSFP-IR: 23.4 ± 7.2 s; bSSFP-PSIR: 21.9 ± 6.4 s) as compared to FLASH-PSIR (361.5 ± 95.33 s). There was no significant difference of mean LGE size for all sequences in all study groups (FLASH-PSIR: 8.96 ± 10.64 g; bSSFP-IR: 8.69 ± 10.75 g; bSSFP-PSIR: 9.05 ± 10.84 g; bSSFP-PSIR free breathing: 8.85 ± 10.71 g, p > 0.05). LGE size was not affected by arrhythmia or absence of breathhold on multi-slice LGE sequences. Conclusions Fast multi-slice and standard segmented LGE sequences are equivalent techniques for the assessment of myocardial fibrosis, independent of an ischemic or non-ischemic etiology. Even in patients with arrhythmia and insufficient breathhold capability, multi-slice sequences yield excellent image quality at significantly reduced scan time and may be used as standard LGE approach. Trial registration ISRCTN48802295 (retrospectively registered)