Echocardiographic score for the screening of cardiac amyloidosis with positive 99m technetium pyrophosphate scintigraphy result

Abstract

AbstractIntroductionSpeckle‐tracking‐derived strains in cardiac chambers may provide better solutions for transthyretin amyloid cardiomyopathy (ATTR‐CM) screening. This study aimed to evaluate the efficacy of biventricular strain measurements using speckle tracking for screening 99mTc‐pyrophosphate (99mTc‐PYP) scintigraphy‐positive cardiomyopathy, which is nearly equivalent to ATTR‐CM.MethodsWe performed a retrospective analysis of transthoracic echocardiographic studies using vendor‐independent speckle tracking analysis in older patients (≥65 years) who underwent 99mTc‐PYP scintigraphy to evaluate the etiology of suspected ATTR‐CM in our institute between January 2019 and December 2022.ResultsThe entire cohort (n = 89) was divided into two subgroups positive 99mTc‐PYP scan results (n = 34) and negative 99mTc‐PYP scan results (n = 55). In the multivariate analysis, posterior wall thickness (p = .003, odds ratio [OR]:1.48, 95% confidence interval [CI]:1.14 –1.92), left ventricular longitudinal strain apical/basal ratio (LVLSapi/bas) (p = .015, OR: 2.78, 95% CI: 1.23–6.32, and right ventricular longitudinal strain (RVLS) (p = .003, OR: 1.15, 95% CI: 1.05 –1.26) were selected to be the most representative echocardiographic findings in 99mTc‐PYP positive cardiomyopathy. The receiver operating characteristic analysis indicated that posterior wall thickness (p < .0001, area under the curve [AUC]: .821, cut‐off value: 14.0 mm), LVLSapi/bas (p < .001, AUC: .802, cut‐off value: 2,16), and RVLS (p < .001, AUC: .791, cut‐off value: ‐18.7%) could significantly detect 99mTc‐PYP positive results with an excellent credibility. Echocardiographic score points calculated using the summary of these three parameters in each patient revealed that a 2‐point score had a fair sensitivity (85%) and an excellent specificity (93%), while a 1‐point score had an excellent sensitivity (91%) and a modest specificity (53%).ConclusionOur proposed echocardiographic screening tool for 99mTc‐PYP scintigraphy‐positive cardiomyopathy may help clinicians manage patients with suspected ATTR‐CM.