REFERENCE RANGES OF NATIVE T1-MAPPING AND EXTRACELLULAR VOLUME FOR CARDIAC AMYLOIDOSIS - A META-ANALYSIS

BackgroundCardiac MRI is central to the evaluation of cardiac amyloidosis (CA). Native T1 mapping and extracellular volume (ECV) are novel MR techniques with evolving utility in cardiovascular diseases, including CA.PurposeTo perform a meta‐analysis of the diagnostic and prognostic data of native T1 mapping and ECV techniques for assessing CA.Study TypeSystematic review and meta‐analysis.PopulationIn all, 3520 patients including 1539 with CA from 22 studies retrieved following systematic search of Pubmed, Cochrane, and Embase.Field Strength/Sequence1.5T or 3.0T/modified Look–Locker inversion recovery (MOLLI) or shortened MOLLI (shMOLLI) sequences.AssessmentMeta‐analysis was performed for all CA and for light‐chain (AL) and transthyretin (ATTR) subtypes. Thresholds were calculated to classify native T1 and ECV values as not suggestive, indeterminate, or suggestive of CA.Statistical AnalysisArea under the receiver‐operating characteristic curves (AUCs) and hazards ratios (HRs) with 95% confidence intervals (95% CI) were pooled using random‐effects models and Open‐Meta(Analyst) software.ResultsSix studies were diagnostic, 16 studies reported T1 and ECV values to determine reference range, and six were prognostic. Pooled AUCs (95% CI) for diagnosing CA were 0.92 (0.89–0.96) for native T1 mapping and 0.96 (0.93–1.00) for ECV, with similarly high detection rates for AL‐ and ATTR‐CA. Based on the pooled values of native T1 and ECV in CA and control subjects, the thresholds that suggested the absence, indeterminate, or presence of CA were identified as <994 msec, 994–1073 msec, and >1073 msec, respectively, for native T1 at 1.5T. Pooled HRs (95% CI) for predicting all‐cause mortality were 1.15 (1.08–1.22) for native T1 mapping as a continuous parameter, 1.19 (1.01–1.40) for ECV as a continuous parameter, and 4.93 (2.64–9.20) for ECV as a binary threshold.Data ConclusionNative T1 mapping and ECV had high diagnostic performance and predicted all‐cause mortality in CA.Level of Evidence1Technical Efficacy Stage2