Prognostic value of multimodality imaging in the contemporary management of cardiac sarcoidosis

Abstract

Background: Echocardiography, cardiac magnetic resonance and cardiac ¹⁸fluorodeoxyglucose positron emission tomography (FDG-PET) imaging play key roles in the diagnosis and management of cardiac sarcoidosis (CS), but the relative value of each modality in predicting outcomes has yet to be determined. This study sought to determine the prognostic importance of multimodality imaging data over and above demographic characteristics and left ventricular ejection fraction (LVEF).

Methods: Consecutive patients newly diagnosed with CS were included. Parameters evaluated included echocardiographic regional wall motion abnormality (RWMA), myocardial strain, LVEF, right ventricular ejection fraction (RVEF), late gadolinium enhancement (LGE) extent, SUVmax and RV FDG uptake. The primary endpoint was a composite of all-cause mortality and serious ventricular arrhythmia.

Results: The study population consisted of 208 patients with mean age of 55±13 years and LVEF of 55±12%. During a median follow-up period of 46 (IQR: 18-55) months, 14 patients died and 28 suffered serious ventricular arrhythmias. On multivariable analysis, RWMA (HR for RWMA presence 2.55, 95% CI 1.27 to 5.28, p=0.008), LGE extent (HR per 1% increase 1.02, 95% CI 1.00 to 1.04, p=0.018), RVEF (HR per 1% decrease 0.97, 95% CI 0.94 to 0.99, p=0.008) and RV FDG uptake (HR for RV FDG presence 2.48, 95% CI 1.15 to 5.33, p=0.020) were independent predictors of the primary endpoint, while LVEF was not predictive. The risk of adverse events was significantly greater in those with LGE extent ≥15% (HR for ≥15% presence 3.96, 95% CI 2.17 to 7.23, p<0.001).

Conclusion: In our CS population, RWMA, LGE extent, RVEF and RV FDG uptake were strong independent predictors of an adverse outcome. These findings offer an important insight into the key multimodality imaging parameters that may be used in a future risk stratification model of patients with CS.

Keywords: Cardiomyopathies; Echocardiography; Magnetic Resonance Imaging; Positron Emission Tomography Computed Tomography.

Figure 1. Patient pathway for the diagnosis or exclusion of cardiac sarcoidosis (CS). Echocardiography, cardiac magnetic resonance (CMR) and ¹⁸fluorodeoxy glucose positron emission tomography (FDG-PET) used in all patients at various diagnostic phases. LVEF, left ventricular ejection fraction.

Figure 2. Risk stratification of patients with cardiac sarcoidosis (CS) using multimodality imaging to predict future all-cause mortality and ventricular arrhythmia (VA). The Kaplan-Meier curves reveal the frequency of all-cause mortality or VA-free survival according to low-risk, intermediate-risk and high-risk groups depending on the presence of cardiac magnetic resonance (CMR) right ventricular systolic dysfunction, extent of late gadolinium enhancement (LGE), presence of regional wall motion abnormality (RWMA) on transthoracic echocardiography (TTE) and presence of right ventricular (RV) ¹⁸fluorodeoxy glucose (FDG)-uptake on PET. Patients with CS in the low-risk, intermediate-risk and high-risk categories experienced an event rate of 2%, 24% and 57%, respectively.

Figure 3. Multimodality imaging predictors in cardiac sarcoidosis and stepwise incremental value to predict major adverse cardiovascular event (MACE). CMR, cardiac magnetic resonance; FDG, ¹⁸fluorodeoxy glucose; LGE, late gadolinium enhancement; RVEF, right ventricular ejection fraction; RWMA, regional wall motion abnormalities; TTE, transthoracic echocardiography.