Late gadolinium enhancement on cardiac magnetic resonance combined with 123I- metaiodobenzylguanidine scintigraphy strongly predicts long-term clinical outcome in patients with dilated cardiomyopathy.

Misato Chimura,Yasuyo Taniguchi,Hiroya Kawai,Shinichiro Yamada,Yoshinori Yasaka

doi:10.1371/journal.pone.0217865

Abstract

Late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) is limited in its ability to detect diffuse interstitial fibrosis, which is commonly found in idiopathic dilated cardiomyopathy (DCM). On the other hand, Washout rate (WR) by cardiac 123I- metaiodobenzylguanidine (123I-MIBG) scintigraphy which evaluates cardiac sympathetic nervous function, is a useful tool for predicting the prognosis in DCM. We investigated the predictive value of the combination of two different types of examinations, LGE on CMR and WR by 123I-MIBG scintigraphy for outcomes in DCM compared with LGE alone. One-hundred forty-eight DCM patients underwent CMR and 123I-MIBG scintigraphy. Patients were divided into 4 groups according to the presence or absence of LGE and WR cut-off value of 45% for predicting prognosis based on receiver operating characteristic curve analysis. Cardiac deaths, re-hospitalization for heart failure, implantation of a left ventricular assist device, and life-threatening ventricular arrhythmias were defined as clinical events. Forty-two DCM patients reached the clinical events during the median follow-up for 9.1 years (interquartile range, 8.0–9.2 years).Multivariable Cox regression analysis identified WR≥45%+LGE positive group as an independent predictor of cardiac events (HR 3.18, 95%CI 1.36–7.45, p = 0.008). Notably, there was no significance in the cardiac event-free survival rate between the WR<45%+LGE positive and WR≥45%+LGE negative groups (p = 0.89). The combination of WR by 123I-MIBG scintigraphy and LGE on CMR, which evaluate different type of cardiac deterioration, serves as a stronger predictor of long-term outcomes in DCM patients than LGE alone.

Highlights

Cardiac magnetic resonance (CMR) is well established as the reference imaging method for the assessment of cardiac anatomy and function [1]
In late gadolinium enhancement (LGE) on CMR image contrast relies on the difference in signal intensity between normal and fibrotic myocardium, so it is difficult to assess the diffuse interstitial fibrosis which is a characteristic fibrotic pattern of dilated cardiomyopathy (DCM) [2]
We conducted a longitudinal study in a cohort of consecutive 470 DCM patients who were referred to Himeji Cardiovascular Center with heart failure (HF) at their initial visit between January 2005 and December 2014

Summary

Introduction

Cardiac magnetic resonance (CMR) is well established as the reference imaging method for the assessment of cardiac anatomy and function [1]. The late gadolinium enhancement (LGE) on CMR by using gadolinium contrast agents, evaluates the myocardial properties and provides the prognostic information about nonischemic cardiomyopathy. In LGE on CMR image contrast relies on the difference in signal intensity between normal and fibrotic myocardium, so it is difficult to assess the diffuse interstitial fibrosis which is a characteristic fibrotic pattern of dilated cardiomyopathy (DCM) [2]. Cardiac imaging with 123I-metaiodobenzylguanidine (123I-MIBG), an analogue of norepinephrine, is a useful tool for detecting abnormal cardiac sympathetic nervous activity in heart failure (HF) patients [3,4,5,6]. Increased sympathetic nervous activity in DCM patients is shown to be associated with a poor prognosis [7,8,9]

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