Impact of amyloid cardiomyopathy diagnosis on heart failure readmission and length of stay

Background Amyloid cardiomyopathy (CM) portends poor outcomes in heart failure (HF). Whether establishing a diagnosis of amyloid CM influences healthcare utilization remains unclear.Methods We identified patients admitted with a primary diagnosis of HF between January 2018 and December 2020, using medical record–linked administrative data. Amyloid CM was diagnosed using technetium-99m pyrophosphate scintigraphy and assessment for paraproteinemia, with endomyocardial biopsy as needed. Annualized HF readmission rates and length of stay (LOS) were compared between patients with confirmed amyloid CM and those referred for testing but without amyloid CM. The date of amyloid testing served as the comparison cutoff.Results Among 108 HF patients referred for amyloid testing, 26 (24%) had amyloid CM. Amyloid CM patients were older (77 vs 69 years, P = 0.003). Annualized HF admission rates were unchanged before and after testing and were similar between amyloid CM and nonamyloid CM groups. Patients with amyloid CM had persistently elevated annualized LOS despite diagnosis confirmation (4.5 vs 3.1 days/patient/year, P = 0.12), whereas nonamyloid CM patients experienced a significant reduction in LOS (2.3 vs 1.3 days/patient/year, P = 0.02).Conclusions HF patients with amyloid CM had persistently high LOS despite the diagnosis, unlike patients without amyloid CM. Additional tailored interventions may be needed to reduce healthcare utilization in this population.