Assessment of Right-Sided Heart Failure in Patients with Dilated Cardiomyopathy using Magnetic Resonance Relaxometry of the Liver.

Abstract

In non-ischemic dilated cardiomyopathy (DC) patients at risk of developing right heart failure (RHF), early depiction of congestive heart failure (CHF) is pivotal to inform about the hemodynamic status and tailor medical therapy. We hypothesized increased liver relaxation times measured at routine cardiovascular magnetic resonance (CMR), reflecting passive hepatic congestion, may be a valuable imaging biomarker to depict CHF. The study cohort consisted of DC patients with LV dysfunction (i.e. ejection fraction <35%) with (n=48) and without (n=46) right ventricular dysfunction (RVD), defined as a right ventricular ejection fraction <35%, and >45%, respectively, and a control group (n=40). Native T1, T2, and extracellular volume (ECV) liver values were measured on routinely acquired cardiac maps. DC+RVD patients had higher C-reactive protein, troponin I and NT-pro BNP values, and worse LV functional parameters than DC-RVD patients (all p<0.001). T1, T2 and ECV Liver values were significantly higher in DC+RVD compared to DC-RVD patients and controls, i.e. T1: 675±88ms vs 538±39ms and 540±34ms; T2: 54±8ms vs 45±5ms and 46±4ms; ECV: 36±7% vs 29±4% and 30±3% (all p<0.001). Gamma-glutamyltranspeptidase (GGT) correlated moderately but significantly with native T1 (r2=0.34), T2 (r2=0.27), and ECV liver (r2=0.23)(all p<0.001). Using right atrial (RA) pressure, as surrogate measure of RHF (i.e. RA pressure >5 mm Hg), native T1 liver yielded at ROC analysis the highest AUC (0.906), significantly higher than ECV liver (0.813), GGT (0.806), T2 liver (0.797), total bilirubin (0.737) and alkaline phosphatase (0.561)(p=0.04). A T1 value of 617ms yielded a sensitivity of 79.5% and specificity of 91.0% to depict RHF. Excellent intra-/inter-observer agreement was found for assessment of native T1/T2/ECV liver values. In conclusion, in DC patients, assessment of liver relaxation times acquired on a CMR exam, may provide valuable information with regard to the presence of RHF.