**Author Listing - Lead/ Submitting Author (we will be communicating with this individual): Name, Institution, City and State where the work was done. Co-authors will be added in a separate section.**
Laura De Michieli - Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padova, Padova, Italy; Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN, USA.

**Main Body of the Abstract**
Background: Technetium Tc 99m pyrophosphate scintigraphy (PYP) is used for the diagnosis of transthyretin amyloid cardiomyopathy (ATTR-CM). Cardiac biomarkers, particularly high sensitivity cardiac troponin (hs-cTn), might be helpful in identifying patients at low or high risk of ATTR-CM.
Objectives: To investigate the predictive value of hs-cTnT (and N-terminal B-type natriuretic peptide, NT-proBNP) in patients undergoing PYP imaging for suspected ATTR-CM in a large US cohort.
Methods: Retrospective study of patients with PYP imaging performed from 2013 to September 2022 and with at least one hs-cTnT available within 6 months from PYP imaging.
Results: A diagnosis of ATTR-CM was made in 427/1442 (30%). A hs-cTnT<6 ng/L (n=50, 3.5%) showed 100% negative predictive value (NPV) (93, 100) and 100% sensitivity (99, 100) for ruling out ATTR-CM. At increasing thresholds, the number of patients potentially ruled out increased but with false negative results. For rule in ATTR-CM, positive predictive value resulted low (15% for hs-cTnT=153 ng/L). Similar results were found for NT-proBNP (n=1378). The combination of hs-cTnT < 12 ng/L and NT-proBNP < 60 ng/L identified 41 patients (3.0%) without ATTR-CM. The combination of hs-cTnT < 14 ng/L and NT-proBNP < 180 ng/L identified 112 patients (8.1%) with 5 false negatives.
Conclusions: In patients undergoing PYP imaging for suspected ATTR-CM, very low hs-cTnT can be of help in ruling out the diagnosis. At increasing thresholds, false negative results are present.  Similar results were found for NT-proBNP and the combination of the two biomarkers. Predictive value in ruling-in the disease appears to be limited.



**Author Listing - Lead/ Submitting Author (we will be communicating with this individual): Name, Institution, City and State where the work was done. Co-authors will be added in a separate section.**
Laura De Michieli - Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padova, Padova, Italy; Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN, USA.

**Main Body of the Abstract**
**Background:** Technetium Tc 99m pyrophosphate scintigraphy (PYP) is used for the diagnosis of transthyretin amyloid cardiomyopathy (ATTR-CM). Cardiac biomarkers, particularly high sensitivity cardiac troponin (hs-cTn), might be helpful in identifying patients at low or high risk of ATTR-CM.
**Objectives:** To investigate the predictive value of hs-cTnT (and N-terminal B-type natriuretic peptide, NT-proBNP) in patients undergoing PYP imaging for suspected ATTR-CM in a large US cohort.
**Methods:** Retrospective study of patients with PYP imaging performed from 2013 to September 2022 and with at least one hs-cTnT available within 6 months from PYP imaging.
**Results:** A diagnosis of ATTR-CM was made in 427/1442 (30%). A hs-cTnT<6 ng/L (n=50, 3.5%) showed 100% negative predictive value (NPV) (93, 100) and 100% sensitivity (99, 100) for ruling out ATTR-CM. At increasing thresholds, the number of patients potentially ruled out increased but with false negative results. For rule in ATTR-CM, positive predictive value resulted low (15% for hs-cTnT=153 ng/L). Similar results were found for NT-proBNP (n=1378). The combination of hs-cTnT < 12 ng/L and NT-proBNP < 60 ng/L identified 41 patients (3.0%) without ATTR-CM. The combination of hs-cTnT < 14 ng/L and NT-proBNP < 180 ng/L identified 112 patients (8.1%) with 5 false negatives.
**Conclusions:** In patients undergoing PYP imaging for suspected ATTR-CM, very low hs-cTnT can be of help in ruling out the diagnosis. At increasing thresholds, false negative results are present.  Similar results were found for NT-proBNP and the combination of the two biomarkers. Predictive value in ruling-in the disease appears to be limited.



Using cardiac troponin to predict abnormal technetium-99m pyrophosphate scans in patients with suspected transthyretin amyloidosis  PB69 (#208)

We invite you to attend the XIX International Symposium on Amyloidosis to be held in Rochester, MN.

This symposium is organized as a hybrid meeting (with the focus on in-person) held from Sunday, May 26 through Thursday, May 30, 2024.

Together with the ISA Board and members of Mayo Clinic, a very attractive scientific hybrid program is being planned. The program will cover a variety of types of systemic amyloidosis: ATTR (hereditary and wild-type), AL (light-chain), AA and less frequent forms. There will be key lectures, specific symposia including those company sponsored, oral presentations and poster sessions of accepted abstracts.

COURSE DESCRIPTION
This program will provide a comprehensive review of state-of-the-art education in systemic amyloidosis: basic science, pathophysiology, diagnosis, current and emerging treatments. Scientific presentations will include competitive oral and poster abstracts. The rapid evolution of scientific discovery and expanding treatment options has created tremendous interest in the field and this meeting will fill and important gap in educating scientists and clinicians.