Long-term prognosis of patients with Perugini Grade 1 cardiac scintigraphy score

Abstract Background A Perugini Grade 1 myocardial uptake on amyloid cardiac scintigraphy does not establish the diagnosis of amyloid transthyretin cardiomyopathy (ATTR-CA), and according to current position papers mandates an endomyocardial biopsy to rule in or rule out ATTR-CA. We aimed to investigate whether Perugini Grade 1 reflects an early stage of ATTR-CA or a false positive result thus obliviating the need for further evaluation. Methods Study population was comprised of consecutive ≥70 years old patients who underwent a baseline cardiac scintigraphy scan for the presumed diagnosis of ATTR-CA at our institution between the years 2017–2020 and had a Perugini Grade 1 score. Patients with Perugini Grade 2 or 3 comprised our control group. At the beginning of 2022, Perugini Grade 1 patients prospectively underwent a repeat follow-up evaluation which included clinical examination, echocardiography with strain parameters, cardiac biomarkers measurement and cardiac scintigraphy. Cardiac magnetic resonance (CMR) and genetic testing for ATTR-CA mutations were analyzed as well. Preliminary results Fifty patients were included in the baseline study cohort, of whom 44% (n=22) were females. A carpal tunnel syndrome history was present in 10 patients (20%). Baseline troponin T and NT pro-BNP levels were 23 (IQR 14,39) and 1557 (IQR 237, 5746) ng/L, respectively. Wall thickness by echocardiography was 12 (11, 15) mm and 8 patients (16%) had severe mitral annulus calcification. Left ventricular ejection fraction (LVEF) was 60 (IQR 50, 60)%. At a median follow-up of 31 (20, 35) months, 7 patients (14%) were diagnosed with plasma-cell dyscrasias and 6 patients (12%) were hospitalized for heart failure exacerbations. Follow-up troponin T and NT pro-BNP levels were 27 (IQR 21,46) pg/ml and 1158 (IQR 434, 7249) ng/L, respectively (p=NS compared to baseline). Wall thickness by echocardiography was 12 (12, 15) mm and LVEF was 60 (IQR 50, 60)% (p=NS compared to baseline). Follow-up cardiac scintigraphy demonstrated Perugini Grade 1 in all re-tested patients. Two patients and 14 patients (32% total) underwent an endomyocardial biopsy or CMR, respectively, for a definitive diagnosis. All 16 tests were incompatible with amyloid cardiomyopathy. Genetic data results will be added. All-cause survival was similar between patients with Perugini Grade 1 versus Grades 2 and 3 (log rank p=0.103). Conclusion At long-term follow-up, Perugini Grade 1 patients do not demonstrate progression of laboratory or imaging amyloid characteristics. This suggests that Perugini grade 1 reflects a false positive result for ATTR-CA rather than an early stage in the disease. Larger-scale data should further question the need for an endomyocardial biopsy in these patients. Funding Acknowledgement Type of funding sources: None.