Noninvasive assessment of clinically significant portal hypertension using ΔT1 of the liver and spleen and ECV of the spleen on routine Gd-EOB-DTPA liver MRI

PURPOSE

To analyze the predictive value of ΔT1 of the liver and spleen as well as the extracellular volume fraction (ECV) of the spleen as noninvasive biomarkers for the determination of clinically significant portal hypertension (CSPH) on routine Gd-EOB-DTPA liver MRI.

METHOD

195 consecutive patients with known or suspected chronic liver disease from 9/2018 to 7/2019 with Gd-EOB-DTPA liver MRI and abdominal T1 mapping were retrospectively included. Based on the presence of splenomegaly with thrombocytopenia, ascites and portosystemic collaterals, the patients were divided into noCSPH (n = 113), compensated CSPH (cCSPH, ≥1 finding without ascites; n = 55) and decompensated CSPH (dCSPH, ascites ± other findings; n = 27). T1 times were measured in the liver, spleen and abdominal aorta in the unenhanced and contrast-enhanced T1 maps. Native T1 times and ΔT1 of the liver and spleen as well as ECV of the spleen were compared between groups using the Kruskal-Wallis test with Dunn's post hoc test. Furthermore, cutoff values for group differentiation were calculated using ROC analysis with Youden's index.

RESULTS

ΔT1 of the liver was significantly lower in patients with cCSPH and dCSPH (p < 0.001) compared to patients with noCSPH. In the ROC analyses for differentiation between noCSPH and CSPH (cCSPH + dCSPH), a cutoff of < 0.67 for ΔT1 of the liver (AUC = 0.79) performed better than ΔT1 (AUC = 0.69) and ECV (AUC = 0.63) of the spleen with cutoffs of > 0.29 and > 41.9, respectively.

CONCLUSION

ΔT1 of the liver and spleen in addition to ECV of the spleen allow for determination of CSPH on routine Gd-EOB-DTPA liver MRI.

Diastolic function assessed my CMR feature tracking is a predictor for outcomes in patients with suspected myocarditis and preserved left ventricular ejection fraction

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.

Visualizing myocardial injury from elective cardioversion with CMR

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Association of Cardiothoracic Anaesthesiologists Research Grant

Background

Despite everyday use of electrical interventions in cardiovascular care, the extent and type of concomitant myocardial injury is not fully understood. Current literature disagrees about the question whether and how cardioversion or defibrillation damage the myocardium, especially when serologic markers are used. Such markers are not always cardiac-specific, nor diagnostic for type and region of myocardial injury. These limitations may be overcome by parametric T1 and T2 mapping. We aimed to investigate whether the acute and long-term impact of electrical cardioversion on myocardial structure and function is detectable using CMR imaging.

Methods

Patients scheduled for elective cardioversion were enrolled to undergo three CMR exams (3 Tesla): on the morning prior to cardioversion to assess pre-existing injury; two to five hours after cardioversion to assess the acute response; and six to ten weeks later to investigate chronic injury. The CMR exam studied left ventricular (LV) function, T2 mapping to measure edema, and extracellular volume (ECV) from T1 maps to measure diffuse fibrosis. Both the degree of injury and proportion (%) of myocardial area affected were analysed.

Results

Eight patients completed the study, requiring 1-2 shocks (totalling 120-300 J biphasic energy) to achieve sinus rhythm. LV ejection fraction increased after cardioversion from 47 ± 13% to 55 ± 15% (p = 0.020), and was 52 ± 16% at the third exam (p = 0.199). Even prior to intervention, some patients showed edema (baseline T2 &gt; 40ms) afflicting 49 ± 23% of their LV myocardium. Area affected by edema expanded to 72 ± 18% after cardioversion (p = 0.002) and returned to 54 ± 24% by the third exam. T2 rose from baseline (40.4 ± 1.8ms) after cardioversion acutely to 44.1 ± 5.2ms (p = 0.028) and normalized until the late exam (40.8 ± 3.1ms). Myocardial area affected by diffuse fibrosis (ECV &gt; 30%) was 28.3 ± 9.4% at baseline and 38.8 ± 18.9% late after cardioversion (p = 0.018). Pathologic T2 increases (indicative of edema) were not observed in all patients, but individuals with higher baseline ECV also experienced greater T2 increase after cardioversion (r = 0.840, p = 0.036).

Conclusion

Elective cardioversion improves LV systolic function, but also aggravates myocardial edema and possibly adds to diffuse fibrosis during several weeks thereafter. Such sequelae of cardioversion were observed mainly in patients with a greater burden of pre-existing myocardial injury. More data is needed to corroborate these preliminary findings and to study whether this type of myocardial injury predicts worse outcome. Moreover, changes in CMR markers caused by electrical interventions including defibrillation, may have the potential to confound diagnostic assessments of the underlying cardiac injury.

Abstract Figure

Changes in right ventricular deformation during hyperoxia versus normoxaemia in patients with stable coronary artery disease and healthy controls

Funding Acknowledgements

Type of funding sources: Public hospital(s). Main funding source(s): Local research funds of the Department of Anaesthesiology and Pain medicine, Bern University Hospital, Inselspital

Background

During anaesthesia, emergency and critical care treatment, patients with coronary artery disease (CAD) are often exposed to supraphysiologic arterial oxygen tensions. The balance between benefits and risks of hyperoxia (HO) in patients with stable CAD is controversial, with reports about reduced left ventricular contractility or increased morbidity and mortality. Effects of HO on right ventricular (RV) function in CAD are less well described. Advanced cardiovascular magnetic resonance (CMR) feature tracking software allows assessment of myocardial deformation, which may serve as early marker of ventricular dysfunction. In a CMR study we quantified the effect of HO on RV function and deformation in awake healthy participants and CAD patients.

Methods

Ten healthy participants and 26 patients with stable one- or two-vessel obstructive CAD were included. In a CMR study, a short-axis function stack of both ventricles was obtained first at room air (RA), then during HO induced by breathing oxygen at 10L/min for 5 minutes via a non-rebreathing facemask. RV strain was analysed by a blinded reader who manually traced epicardial and endocardial contours of the RV for determining peak global circumferential strain (RVGCS), time to peak strain, systolic and diastolic strain rate parameters.

Results

RV ejection fraction did not change with O2 breathing in the healthy control group (RA, 56 ± 12% vs. HO, 55 ± 10%, p = 0.999) nor in the CAD group (RA, 60 ± 8% vs. HO, 60 ± 9%, p = 0.609). RV cardiac index decreased significantly in CAD patients from RA (2.62 ± 0.88 L/min/m2) to HO (2.42 ± 0.77L/min/m2, p = 0.002). The decrease in the control group was not significant (RVCI: RA 3.28 ± 1.29 vs HO 3.04 ± 1.27L/min/m2 p = 0.068).

In the healthy control group, RVGCS, time to peak strain, and systolic strain rate did not change significantly with HO (RVGCS: RA, -14.6 ± 3.9% vs. HO, -13.1 ± 4.5%, p = 0.353; time to peak strain: 282 ± 45ms vs. 286 ± 29ms, p = 0.540; and systolic strain rate: -0.85 ± 0.27/s vs. -0.67 ± 0.28, p = 0.055).

In CAD patients RVGCS worsened from -14.8 ± 3.3% on RA to -13.9 ± 3.6% at HO (p = 0.040). Time to peak strain became significantly prolonged from 319 ± 40ms on RA to 329 ± 49ms at HO (p = 0.046). This was accompanied by a reduction of systolic strain rate from -0.79 ± 0.27/s to -0.75 ± 0.22/s (p = 0.037). Diastolic strain parameters did not differ significantly between RA and HO in either group.

Conclusion

In our cohort of CAD patients HO significantly reduced RV cardiac index and impaired systolic deformation as determined by CMR feature tracking. Studies are required in a larger patient cohort with regional analysis and assessment of longitudinal and radial deformation to assess the role of hyperoxia in CAD.

Abstract Figure. Change in RV Peak Circumferential Strain