Estimated total amyloid burden from 18F-florbetaben PET predicts all-cause mortality in light-chain cardiac amyloidosis
Giuseppe Vergaro, Alberto Aimo, Dario Genovesi, Lucas Soares Bezerra, Vincenzo Castiglione, Iacopo Fabiani, Andrea Barison, Giorgia Panichella, Maria Livia Del Giudice, Lara Camerini, Giovanni Dugo, Olena Chubuchna, Assuero Giorgetti, Gabriele Buda, Michele EmdinAbstract
Background and Aims
The positron emission tomography (PET) tracer 18F-florbetaben is a promising diagnostic tool for light-chain cardiac amyloidosis (AL-CA). A greater cardiac uptake might signal more amyloid burden and a worse outcome. We aimed to assess the prognostic significance of 18F-florbetaben uptake in AL-CA.
Methods
Consecutive patients with AL-CA underwent 18F-florbetaben PET scans. Total amyloid burden (TAB; calculated as mean standardized uptake value multiplied by molecular volume) was assessed in the left and right ventricles (LV/RV) in early (5-15’) and late (50-60’) acquisitions. The endpoint was all-cause mortality.
Results
Forty patients (median age 69 years, 73% males, Mayo 2004 stage III in 80%) underwent 18F-florbetaben PET with a median time from tissue biopsy of 21 days (interquartile range, IQR 7-83). Late LV TAB, but not early LV TAB, correlated with N-terminal pro-BNP (NT-proBNP) and hs troponin T. Over 13 months after the PET scan (IQR 5-21), 65% of patients died. A late LV TAB ≥273 cm3 (cut-off derived from spline curve analysis) predicted 18- and 24-month all-cause mortality independently from baseline variables, including NT-proBNP, hs-troponin T, and Mayo 2004 stage. Late RV TAB ≥135 cm3 independently predicted 18- and 24-month all-cause mortality. Patients with both late LV and RV TAB ≥cut-offs had a shorter survival than those with only LV TAB ≥cut-off and those with TAB in both ventricles <cut-offs (Log-rank 16.52, p<0.001).
Conclusions
18F-florbetaben PET imaging offers valuable prognostic information in AL-CA. Values of late TAB measured in the LV and RV are strong predictors of all-cause mortality.