Abstract 12473: Majority of Technetium-99m Pyrophosphate Scans for the Evaluation of Transthyretin Cardiac Amyloidosis Are Ordered Without Appropriate Paraprotein Evaluation

Abstract

Background: Guidelines recommend the use of technetium-99 m pyrophosphate (PYP) scanning after light chain amyloidosis has been ruled out via laboratory testing. Yet lack of execution of this condition significantly hinders the real-world value of PYP scanning to diagnose transthyretin amyloidosis. Objective: The aim of this study was to evaluate the prevalence and consequences of inappropriate PYP scanning at an academic, tertiary care center. Methods: We performed a retrospective study of all PYP scans ordered at our institution from January 2018 to March 2023. Categorical variables were determined as frequencies and percentages. Continuous variables were determined as means and standard deviations. Results: 269 PYP scan orders were identified from 228 distinct patients. Mean age was 67.04 years, 51.2% of patients were female, 66.5% were White, and 47.7% were Hispanic. 52 PYP scans (19.3%) should not have been ordered given positive paraprotein results. 145 PYP scans (53.9%) should not have been ordered given lack of any paraprotein results. Only 9 scans (3.3%) were ordered after negative serum free light chain, serum protein electrophoresis, and serum immunofixation results. Up to seven patients (3.1%) did not receive appropriate paraprotein evaluation prior to tafamidis initiation and thus may have been erroneously treated, representing potential unnecessary healthcare costs to not only the patient, but also the healthcare system. There were no temporal trends for scans performed with zero, three, or positive paraprotein results ( Figure ). Conclusions: Most patients did not undergo complete serum monoclonal protein testing prior to PYP scan ordering. Many patients underwent PYP scanning despite positive serum monoclonal protein test results. Increased awareness and education among physicians regarding paraprotein evaluation prior to PYP scanning is still needed to prevent misdiagnosis, delayed diagnosis, and unnecessary healthcare costs.