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Background Heart failure culminates in liver congestion. As the liver can be assessed by cardiac magnetic resonance T1 mapping sequences, it represents a promising imaging biomarker for heart failure. Objectives To evaluate the association between heart failure and magnetic resonance liver T1 mapping, as a non-invasive imaging surrogate of liver congestion. Methods Patients with cardiac magnetic resonance including T1 mapping sequences on a single 1.5T scanner were consecutively included between 01/2017 and 12/2019. Liver T1 was measured in the left lobe, right lobe and caudate lobe on short axis view and in the liver dome on four chamber view. Echocardiographic and laboratory parameters were analyzed within 90 days of the cardiac magnetic resonance exam. Left ventricular filling pressures were assessed according to the European Association of Cardiovascular Imaging guidelines [1]. Liver T1 and echocardiographic parameters were compared between patients with and without elevated NT-proBNP levels (>125 pg/ml) using a Mann-Whitney U test. A multivariate logistic regression model was used to correct for age, sex, body mass index, left ventricular ejection fraction and the presence of atrial fibrillation. Results A total of 397 patients were included (median age 56, 127 females), of whom 138 patients (35%) presented with elevated NT-proBNP levels. Patients with elevated NT-proBNP levels had a larger indexed end-diastolic left ventricular volume (92 vs. 81 ml/m2, p<0.001), lower left ventricular ejection fraction (60 vs. 50%, p<0.001) and a higher E/E' ratio (11 vs. 8, p<0.001). Liver T1 was higher in patients with elevated NT-proBNP in the right liver lobe (670 vs. 596 ms, p<0.001) and the caudate lobe (664 vs. 598 ms, p<0.001), but not in the left liver lobe (571 vs. 568 ms, p=0.068) and in the liver dome (590 vs. 560 ms, p=0.1). Echocardiographic evaluation showed similar results with significant difference in T1 times between patients with elevated and non-elevated left ventricular filling pressures in caudate and right liver lobe. Liver T1 retained its predictive value when corrected for age, left ventricular ejection fraction and the presence of atrial fibrillation, when measured in the caudate lobe (adjusted odds ratio 1.013, 95% confidence interval 1.004–1.023, p=0.005) and in the right lobe (adjusted odds ratio 1.012, 95% confidence interval 1.003–1.021, p=0.009). Conclusions Elevated liver T1 in cardiac magnetic resonance imaging is associated with heart failure and represents an independent non-invasive imaging surrogate for liver congestion. Funding Acknowledgement Type of funding sources: None.

Background Positron emission tomography myocardial perfusion imaging (PET MPI) is a robust and excellent tool for assessing ischemia. So far, however, no methodology has been established to distinguish truly reduced MFR due to microvascular dysfunction or three-vessel coronary disease (CAD) from seemingly impaired MFR due to inadequate adenosine response. Conversely, for cardiac stress magnetic resonance (CMR) the adenosine induced splenic switch-off (SSO) sign has been proposed as a potential marker for adequate adenosine response. Purpose We assessed the feasibility of detecting SSO in adenosine stress 13N-ammonia PET MPI using SSO in CMR as the standard of reference. Methods 50 patients underwent simultaneous PET MPI and CMR on a hybrid PET/MR device with co-injection of 13N-ammonia and a gadolinium-based contrast agent during rest and adenosine-induced stress. In CMR, SSO was assessed qualitatively and quantitatively by calculating the ratio of the peak signal intensity of the spleen during stress over rest (SIR). Similarly, in PET MPI the splenic signal activity ratio (SAR) was calculated as the proportion of the maximal standard uptake value of the spleen in stress and rest. Additionally, MFR was quantified in PET MPI. Results Visual SSO in CMR was present in 37 (74%) patients, whereas 13 patients had no SSO. The median SIR in CMR was significantly lower in patients with visual SSO compared to patients without visual SSO (0.57 [IQR 0.49–0.62] vs. 0.89 [IQR 0.76–0.98]; p<0.001). Similarly, median SAR in PET was significantly lower in patients with visual SSO in CMR compared to patients without visual SSO (0.4 [IQR 0.32–0.45] vs. 0.8 [IQR 0.47–0.98]; p<0.001). SIR correlated significantly with SAR (r=0.4, p<0.05). Mean MFR was significantly higher in patients with visual SSO compared to patients without visual SSO (3.38±0.86 vs. 2.53±0.84; p<0.05). Conclusion Similarly to CMR, SSO can be detected in 13N-ammonia PET MPI. This might help distinguish adenosine non-responders from patients with truly impaired MFR due to microvascular dysfunction or multivessel CAD. Figure 1. Splenic switch off (*) illustrated on transaxial 13N-ammonia PET MPI stress (A) compared to rest perfusion images (B) and similarly in stress (C) and rest (D) short axis CMR (**) in the same patient during adenosine induced stress and co-injection of 13N-ammonia and a gadolinium based contrast agent, acquired on a hybrid PET/MR device. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Swiss National Science Foundation (SNSF)

Funding Acknowledgements Type of funding sources: None. Diastolic function assessed my CMR feature tracking is a predictor for outcomes in patients with suspected myocarditis and preserved left ventricular ejection fraction Background Impairment of left ventricular (LV) systolic function was reported to be a valuable predictor for outcomes in patients with myocarditis. However, in patients with myocarditis and preserved LV systolic function, prediction of outcomes remains challenging. So far, minimal data exists about the prognostic role of diastolic function, as assessed by cardiac magnetic resonance imaging (CMR) in the clinical setting of suspected myocarditis. Purpose To determine the predictive value of LV diastolic function in patients with suspected myocarditis and preserved LV ejection fraction (LVEF). Methods In patients referred for CMR with clinically suspected myocarditis and LVEF≥50%, diastolic function was assessed by CMR feature tracking (FT). The primary endpoint was defined as a composite of major adverse cardiovascular events (MACE) including hospitalization for heart failure, recurrent myocarditis, sustained ventricular tachycardia and all-cause death. Results Of 381 patients included with clinically suspected myocarditis (216, 56.7% male, mean age 45.7 ± 16.4 years) late gadolinium enhancement (LGE) was present in 124 (32.4 %) of patients (mean LGE extent 4.9 ± 5.0 g). MACE occurred in 25 (6.6%) individuals at a median follow-up time of 4.5 years. In a univariate cox-regression model, radial, circumferential and longitudinal early diastolic strain rate (EDSR) and circumferential late diastolic strain rate were significantly associated with MACE. After adjustment for age, gender and extent of LGE, radial EDSR remained an independent predictor for MACE (HR = 2.26, 95% CI 1.06 to 4.8; p = 0.034). Conclusion Diastolic strain rate, as assessed by CMR-FT, can be useful in the prediction of outcomes in patients with myocarditis and preserved LVEF.