부산대학교 도서관

Introduction: While technetium pyrophosphate (Tc-PyP) is known to be highly accurate for identifying transthyretin cardiac amyloidosis (ATTR-CA), it is currently unclear whether the grade of uptake observed on Tc-PyP correlates with either amyloid burden or adverse cardiac remodeling.Methods: At three academic medical centers, we retrospectively identified patients with confirmed ATTR-CA—defined in accordance with guidelines using either tissue biopsy or grade ≥2 Tc-PyP uptake—who underwent Tc-PyP and cardiac magnetic resonance (CMR) at 1.5T (Phillips, Siemens or GE). Left (LV) and right (RV) ventricular size, mass, and systolic function were quantified. T1 mapping including extracellular volume (ECV)—a surrogate for amyloid burden—was quantified according to guidelines. 3-hour Tc-PyP grade was assessed in accordance with guidelines. CMR markers were correlated with Tc-PyP grade using ANOVA with pair-wise comparisons made using t-test, Wilcoxon rank, or chi-squared as appropriate with p<0.01 used to denote significance.Results: 45 patients were included (mean age 75.4 years, 75.6% male). Within the cohort, grade 0, 1, 2, and 3 uptake were present in 1(2%), 3(7%), 6(13%), and 35(78%) patients respectively. All patients with Tc-PyP grade <2 were confirmed to have ATTR-CA by endomyocardial biopsy. Neither age, gender, or comorbidities differed significantly based on Tc-PyP uptake (Panel A). In univariate analysis, both indexed LV mass and ECV were significantly associated with Tc-PyP grade (Panel B). As compared to those with grade 2, patients with grade 3 Tc-PyP uptake had significantly higher ECV (p<0.001) and indexed LV mass (p=0.003).Conclusions: The presence of higher Tc-PyP grade is associated with increasing amyloid burden and a greater degree of adverse LV remodeling. Higher Tc-PyP grade appears to be indicative of more advanced disease stage in this patient population.