Spatial Dispersion Analysis of LGE-CMR for Prediction of Ventricular Arrhythmias in Patients with Cardiac Sarcoidosis

Abstract

Background: Patients with cardiac sarcoidosis (CS) are at increased risk of life-threatening ventricular arrhythmias (VA). Current approaches to risk stratification have limited predictive value. Objectives: To assess the utility of spatial dispersion analysis of LGE-CMR, as a quantitative measure of myocardial tissue heterogeneity, in risk stratifying patients with CS for ventricular VA and death. Methods: 62 patients with CS underwent LGE-CMR. LGE images were segmented and dispersion maps of the left and right ventricles were generated as follows. Based on signal intensity (SI), each pixel was categorized as abnormal (SI {greater than or equal to}3SD above the mean), intermediate (SI 1-3 SD above the mean) or normal (SI <1SD above the mean); and each pixel was then assigned a value of 0-8 based on the number of adjacent pixels of a different category. Average dispersion score (DS) was calculated for each patient. The primary endpoint was VA during follow up. The composite of VA or death was assessed as a secondary endpoint. Results: During 4.7{plus minus}3.5 years of follow up, 6 patients had VA, and 5 without documented VA died. Average DS was significantly higher in patients with VA versus those without (0.87{plus minus}0.08 vs 0.71{plus minus}0.16; p=0.002) and in patients with events versus those without (0.83{plus minus}0.08 vs 0.70{plus minus}0.16; p=0.003). Patients at higher tertiles of DS had a higher incidence of VA (p=0.03) and the composite of VA or death (p=0.01). Conclusions: Increased substrate heterogeneity, quantified by spatial dispersion analysis of LGE-CMR, may be helpful in risk-stratifying patients with CS for adverse events, including life-threatening arrhythmias.