Background: Previous publications about the association between fatty-acid binding protein 4 (FABP4) and cardiac remodeling have reported different, both beneficial and harmful, associations. Aim of the present investigation was to evaluate the association of FABP4 with parameters of myocardial remodeling defined by cardiac magnetic resonance imaging (CMR). Methods: We investigated plasma FABP4 levels in 331 patients (71% men, mean age 63±13 years) with preserved left ventricular ejection fraction (LVEF ≥ 55%) who underwent a CMR examination. We used linear cox regression to investigate associations between FABP4 and left ventricular end-diastolic diameter (LVEDD), right ventricular enddiastolic diameter (RVEDD), relative wall thickness (RWT), left ventricular mass index (LVMI), and LVEF (unadjusted and adjusted for age, sex, body mass index, cardiac biomarkers, and comorbidities). Results: FABP4 levels were associated with lower LVMI and higher NT-proBNP levels in an adjusted model. The inverse association between FABP4 and LVMI was more pronounced in lower FABP4 levels, whereas the positive association between FABP4 and NT-proBNP was more pronounced in relatively high NT-proBNP levels. Conclusions: Possible beneficial and harmful associations between FABP4 and left ventricular size have been reported. Our results suggest a beneficial association with LVMI (more pronounced in lower FABP4 levels) but a harmful association with NT-proBNP (more pronounced in higher FABP4 levels). Therefore, our results might indicate a potential dose-dependent association of FABP4, but this observation needs further investigation in larger study samples.

Background and aim Obese individuals have a high risk of developing heart failure independent of concomitant diseases like diabetes mellitus or arterial hypertension. Hormones secreted by adipose tissue, so-called adipokines such as retinol binding protein 4 (RBP4) or fatty-acid binding protein 4 (FABP4), might constitute a link between obesity and cardiomyopathy. RBP4 is known to be associated with left ventricular hypertrophy, whereas FABP 4 has been reported to display anti- as well as pro-hypertrophic properties. Purpose The aim of the present study was to investigate the association of FABP4 and RBP4 with cardiac magnet resonance imaging (MRI) parameters. Methods We investigated plasma FABP4 and plasma RBP4 levels in 210 patients (70% men, mean age 63 years) who underwent an MRI examination and tested whether FAPB4 and RBP4 levels were associated with the following MRI parameters using linear cox regression: left ventricular end-diastolic diameter (LVEDD), interventricular septal (IVS) wall thickness, posterior wall thickness (PWT), relative wall thickness (RWT), left ventricular mass index (LVMI), and left ventricular ejection fraction (LVEF). An unadjusted model and a model adjusted for age, sex, body mass index, diabetes mellitus, arterial hypertension, smoking, presence of coronary artery disease, and heart rate were used. Results FABP4 levels were associated with higher PWT (p=0.0044, est. = 0.4) and RWT (p=0.0011, est. = 0.02). The associations were significant in the fully adjusted model (for PWT p=0.013, for RWT p=0.0043). We observed a non-linear, U-shaped relationship between FABP4 and LVEDD, RVEDD, and LVMI. FABP4 levels below the median were associated with lower LVEDD (p=0.0239, est. = −2.7), RVEDD (p=0.0127, est. = −3.3) and LVMI (p<0.001, est. = −7.9). The association were significant in the fully adjusted model for LVMI only (p=0.0016). The associations between FABP4 levels above the median and LVEDD, RVEDD, and LVMI tended to be positive but were not statistically significant. In the unadjusted model, RBP4 was associated with higher IVS (p=0.005, est. = 0.59), PWT (p=0.0135, est. = 0.37), and RWT (p=0.036, est. = 0.02); these associations were not significant in the fully adjusted model. Interestingly, an interaction was observed between age and RBP4 in the association with IVS (p interaction = 0.01). Higher RBP4 and older age might have a stronger effect on IVS than age and RBP4 alone (see Figure). Conclusion Anti- and pro-hypertrophic associations between FABP4 and left ventricular size have been reported. Our results suggest that the pro- and anti-hypertrophic effects of FABP4 are dependent on FABP4 concentrations: lower FABP4 levels have an anti-hypertrophic effect, whereas higher levels have a pro-hypertrophic effect. RBP4 was associated with parameters of cardiac hypertrophy determined by MRI, suggesting a possible link between obesity and cardiomyopathy in an age dependent manner.

Purpose Left ventricular (LV) longitudinal, circumferential, and radial motion can be measured using feature tracking of cardiac magnetic resonance (CMR) images. The aim of our study was to detect differences in LV mechanics between patients with dilated cardiomyopathy (DCM) and ischemic cardiomyopathy (ICM) who were matched using a propensity score-based model. Methods Between April 2017 and October 2019, 1224 patients were included in our CMR registry, among them 141 with ICM and 77 with DCM. Propensity score matching was used to pair patients based on their indexed end-diastolic volume (EDVi), ejection fraction (EF), and septal T1 relaxation time. Feature tracking provided six parameters for global longitudinal, circumferential, and radial strain with corresponding strain rates. Results Propensity score matching yielded 72 patients in each group (DCM mean age 58.6 ± 11.6 years, 15 females; ICM mean age 62.6 ± 13.2 years, 11 females, p = 0.084 and 0.44 respectively; LV-EF 32.2 ± 13.5% vs. 33.8 ± 12.1%, p = 0.356; EDVi 127.2 ± 30.7 ml/m² vs. 121.1 ± 41.8 ml/m², p = 0.251; native T1 values 1165 ± 58 ms vs. 1167 ± 70 ms, p = 0.862). There was no difference in global longitudinal strain between DCM and ICM patients (-10.9 ± 5.5% vs. -11.2 ± 4.7%, p = 0.72), whereas in DCM patients there was a significant reduction in global circumferential strain (-10.0 ± 4.5% vs. -12.2 ± 4.7%, p = 0.002) and radial strain (17.1 ± 8.51 vs. 21.2 ± 9.7%, p = 0.039). Conclusion Our data suggest that ICM and DCM patients have inherently different myocardial mechanics, even if phenotypes are similar. The ability to discriminate these two conditions may aid in developing additional prognostic and therapeutic strategies in the future.

Background Adult heart failure in industrialized nations is primarily due to dilated (DCM) and ischemic cardiomyopathy (ICM). Both diseases are characterized by different pathological pathways. While ICM is predominantly caused by local, subendocardial myocyte necrosis, DCM is characterized by a general myocyte apoptosis involving all myocardial layers. Using feature tracking, longitudinal, circumferential, and radial motion of the left ventricle (LV) can be measured, which allows the function of subendocardial, mostly longitudinal orientated, and subepicardial, mostly circumferential orientated fibers to be assessed independently. Purpose It was the aim of our study to detect differences of LV motion between DCM and ICM patients in a propensity score-matched cohort. Methods Between April 2017 and December 2018 we included 845 patients with a clinical indication for CMR in our tertiary care center registry. Out of this cohort we identified 273 patients with ICM and 126 with DCM. Propensity score matching was used to pair patients in each group based on their indexed enddiastolic volume (EDVi), ejection fraction (EF), septal T1. Feature tracking technique was used for strain analyses quantified on steady state free precession cine CMR images yielding six strain parameters. Results Propensity score matching yielded 59 patients in each group (ICM mean age 59.4±13.0 years, 11 females; DCM mean age 66.5±10.6 years, 15 females; LV-EF 32.6±11.4% vs. 33.0±14.2%, p=0.8178; EDVi 124.2±36 ml/m2 vs. 132.9±42 ml/m2, p=0.0909; native T1 values 1161±66 ms vs. 1164±59 ms, p=0.7049). There was no difference in global longitudinal strain between ICM and DCM patients (−10.9±4.4% vs. −10.6±5.8%, p=0.686), whereas global circumferential strain and radial strain were reduced in DCM patients (−12.0±4.3% vs. −10.31±4.8%, p=0.0190 and 21.1±8.9% vs. 18.0±15.5%, p=0.0386). Conclusion Our data confirm the inherently different mechanics of ICM and DCM patients. While myocardial fibres are globally affected in DCM, myocardial damage is predominantly confined to subendocardial layers in ICM despite equally reduced EF.

Background Graft failure caused by allograft rejection and vasculopathy is the most common cause of mortality after heart transplantation. To detect an early allograft rejection, endomyocardial biopsy is still needed. Tissue characterization by T1-mapping and Late gadolinium enhancement is well established in acute and chronic myocardial tissue alterations. Therefore several studies investigated T1-mapping as a potential noninvasive parameter to monitor cardiac allograft vasculopathy and allograft rejection. However it is unclear if T1 is also influenced by pretransplant ischemic time and elapsed time since transplantation. Purpose It was the aim of our study to examine the influence of ischemic and elapsed time since transplantation to the cardiac allograft tissue characteristics measured by CMR T1 relaxation times. Methods Allograft transplant patients underwent stress CMR on a yearly routine. T1-maps were acquired using a modified look locker sequence (MOLLI 3(2)3(2)5) in the midventricular septum. Uni- and multi linear regression analysis was used to predict T1 by ischemic time, time since transplantation, troponin and NT-Pro-BNP. Results 49 cardiac allograft transplanted patients underwent stress CMR (mean age 58.6±11.7 years, left ventricular ejection fraction 62.1±6.8%; indexed enddiastolic volume 68.4±14.7 ml/m2; native T1 1120±51 ms, extracellular volume 0.27±0.04). A significant correlation was found between T1 and NT-Pro-BNP (1519±3639 pg/ml, p=0.003) and a trend for troponin (17.0±12.8 ng/dl, p=0.051). We saw no correlation between T1 and the ischemic time (198.4±44.9 minutes, p=0.1172) and elapse time since transplantation (47±7 month, p=0.9868). In the multivariate regression analysis none of the four parameters were independently associated with the T1 time (p=0.1017). Table 1 Characteristics Mean ± SD p Ischemic time (minutes) 198.4±44.9 0.1172 Time since transplant (month) 47±7 0.9868 NT-Pro-BNP (pg/ml) 1519±3639 0.003 Troponine (ng/dl) 17.0±12.8 0.051 Conclusion There was no significant effect of pretransplant ischemic time and elapse time since transplantation on native T1 times, whereas native T1 was significantly correlated with troponine and NT-Pro-BNP-Levels. T1 is excellently suited to detect acute changes in allograft transplant patients without being influenced by aging of the transplanted heart and the heart's pretransplant condition.