Abstract 14106: Prevalence and Respective Predictive Value of Late Gadolinium Enhancement Phenotypes in Patients Referred for Suspected Infiltrative Cardiomyopathy

Abstract

Introduction: The respective value of different late gadolinium enhancement (LGE) phenotypes in patients with suspected infiltrative cardiomyopathy remains uncertain. Methods: In a large cohort of patients referred for suspected infiltrative cardiomyopathy, we evaluated respective associations between the dominant LGE phenotype and the composite endpoint of heart failure hospitalization, survived cardiac arrest or death. Kaplan-Meier survival curves were executed for six pre-defined LGE phenotypes. Multivariable analysis was performed to assess their independent association with the composite outcome, adjusted for relevant confounders. Final diagnosis was adjudicated using standardized disease-specific criteria. Results: 588 patients (68% male, median age 70 years, mean LVEF 54.7±12.7%) were studied. Of these patients, 139 (24%) were confirmed to have cardiac amyloidosis (CA) (81 [58%] transthyretin, 54 [39%] light chain and 4 [3%] undifferentiated) by objective non-CMR diagnostic criteria. Any LGE was present in 394 patients (67%) with the dominant phenotype being diffuse in 137 (23%), mid-wall patchy in 118 (20%), ischemic in 55 (9.4%), subepicardial in 18 (3.1%), mid-wall striae in 8 (1.4%), and RV insertion site in 58 (9.9%). The sensitivity and specificity of diffuse LGE for CA was 86% and 96%, respectively. Over a median 855 (IQR 372, 1542) days, 239 (41%) experienced the primary outcome. Unadjusted survival curves for each LGE phenotype are shown in the Figure. Following adjustment, diffuse (HR 2.30, p<0.001), mid-wall patchy (HR 1.52, p=0.040) and ischemic LGE (HR 1.78, p=0.023) remained independently associated (Figure). Conclusions: In patients referred for suspected infiltrative cardiomyopathy, diffuse, mid-wall patchy and ischemic patterns all showed independent prognostic value. We confirm that diffuse LGE pattern reliably identifies CA patients with high sensitivity and specificity while delivering strong prognostic value.