Background and Objectives: Heart failure with preserved ejection fraction (HFpEF) and atrial fibrillation (AF) frequently occur together.However, data on AF subtype and its association with comorbidities, extracellular volume (ECV) by cardiac magnetic resonance imaging (CMR), hemodynamics, and relation to outcome in HFpEF are sparse. Methods and Results:From 2011 to 2015 152 consecutive HFpEF patients were enrolled in our prospective observational registry.All patients underwent echocardiography, left and right heart catheterization (RHC), and CMR including T1 mapping with the modified Look-Locker inversion recovery (MOLLI) sequence.Patients with significant coronary artery disease were excluded.105 patients (69%) suffered from AF, 85 (56%) had persistent and 20 (13%) had paroxysmal AF.Patients with persistent AF were in worse New York Heart Association functional class (p¼0.006), and more often suffered from chronic obstructive pulmonary disease (p¼0.018)than patients with paroxysmal AF or sinus rhythm.They had higher levels of N-terminal pro-brain natriuretic peptide (NTproBNP) (p¼<0.001),and worse renal function (p¼0.041).Invasive hemodynamics showed higher right atrial pressures (p¼0.014) and pulmonary capillary wedge pressures (p¼0.050).Echocardiography revealed more pronounced atrial dilatation (p¼<0.001) as well as a more dilated right ventricle (p¼0.001) and higher systolic pulmonary artery pressures (p¼0.037).By CMR left and right atria as well as the right ventricle were more dilated (p¼0.001,0.002, and 0.001, respectively) and left and right ventricular ejection fractions were lower in patients with persistent AF (p¼0.002 and <0.001 respectively).Furthermore, these patients had higher levels of ECV by T1 mapping (p¼0.018).After a median follow-up of 46 months (13-71) 63 patients (41%) reached the combined endpoint defined as hospitalization for HF and/or cardiovascular death.By multivariate Cox regression analysis only persistent AF (p¼0.039,HR 2.013, 95% CI 1.035-3.915)and six-minute walk distance (p¼0.013,HR 0.997, 95% CI 0.994-0.999)were independently associated with outcome.Conclusion: More than 50% of HFpEF patients suffer from persistent AF.Persistent but not paroxysmal AF is significantly related with markers of disease severity, extracellular volume accumulation, and worse cardiovascular outcome.
Diffuse myocardial fibrosis is a key pathophysiologic feature in heart failure and can be quantified by cardiac magnetic resonance (CMR) T1 mapping. However, increases in myocardial free water also prolong native T1 times and may impact fibrosis quantification. Thus far, the impact of systemic patient volume status remains unclear. In this study, native T1 time by CMR was investigated in hemodialysis (HD) patients (n = 37) and compared with healthy controls (n = 35). Volume status was quantified by bioimpedance spectroscopy and correlated with CMR T1 time. While no differences between HD patients and controls were present with regard to age (p = 0.180), height (p = 0.535), weight (p = 0.559) and left ventricular (LV) ejection fraction (p = 0.273), cardiac size was significantly larger in HD patients (LV end-diastolic volume 164 ± 53 vs. 132 ± 26 ml, p = 0.002). Fluid overloaded HD patients had significantly longer native T1 times than normovolemic HD patients and healthy controls (1,042 ± 46 vs. 1,005 ± 49 vs. 998 ± 47 ms, p = 0.030). By regression analysis, T1 time was significantly associated with fluid status (r = 0.530, p = 0.009, post-HD fluid status). Our data strongly indicate that native CMR T1 time is significantly influenced by systemic volume status. As fluid overload is common in patients with cardiovascular diseases, this finding is important and requires further study.
Myocardial extracellular volume (ECV) accumulation is one of the key pathophysiologic features of heart failure with preserved ejection fraction (HFpEF). Our aims were to (1) measure ECV by cardiac magnetic resonance T1 mapping using the modified Look-Locker inversion recovery (MOLLI) sequence, (2) validate MOLLI-ECV against histology, and (3) investigate the relationship between MOLLI-ECV and prognosis in HFpEF.One-hundred seventeen consecutive HFpEF patients underwent cardiac magnetic resonance imaging, coronary angiography, and invasive hemodynamic assessments at baseline. Eighteen patients also underwent left ventricular biopsy for histological analysis (Histo-ECV). To assess the prognostic impact of MOLLI-ECV, its association with hospitalization for heart failure/cardiac death was tested by multivariable Cox regression analysis. Histo-ECV was 30.1±4.6% and was significantly correlated with MOLLI-ECV (R=0.494, P=0.037). Patients were followed for 24.0 months (6.0-32.0 months), during which 34 had a cardiac event. By Kaplan-Meier analysis, patients with MOLLI-ECV ≥ the median (28.9%) had shorter event-free survival (log-rank, P=0.028). MOLLI-ECV significantly correlated with N-terminal prohormone of brain natriuretic peptide (P<0.001), 6-minute walk distance (P=0.004), New York Heart Association functional class (P=0.009), right atrial pressure (P=0.037), and stroke volume (P=0.043). By multivariable Cox regression analysis, MOLLI-ECV was associated with outcome among imaging variables (P=0.038) but not after adjustment for clinical and invasive hemodynamic parameters.We demonstrate that MOLLI-ECV in HFpEF accurately reflects histological ECV, correlates with markers of disease severity, and is associated with outcome among cardiac magnetic resonance parameters but not after adjustment for important clinical and invasive hemodynamic parameters. Nevertheless, MOLLI-ECV has the potential of becoming an important biomarker in HFpEF.
For the future X-ray astronomy project Advanced Telescope for High ENergy Astrophysics plus (ATHENA+) wafer-scale DEpleted P-channel Field Effect Transistor (DEPFET) detectors are proposed as Focal Plane Array (FPA) for the Wide Field Imager (WFI). Prototype structures with different pixel layouts, each consisting of 64 x 64 pixels, were fabricated to study four different DEPFET designs. We report on the results of the electrical characterization of the different DEPFET designs. The transistor properties of the DEPFET structures are investigated in order to determine whether the design intentions are reflected in the transistor characteristics. In addition yield and homogeneity of the prototypes can be studied on die, wafer and batch level for further improvement of the production technology with regard to wafer-scale devices. These electrical characterization measurements prove to be a reliable tool to pre-select the best detector dies for further integration into full detector systems.
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