Author + information
- Hallie Gellera,b,
- Avinainder Singha,b,
- Tara Mirtoa,b,
- Robert Paderaa,b,
- Richard N. Mitchella,b,
- Jacob P. Laubacha,b and
- Rodney Falka,b
Background: Monoclonal gammopathy (MG) is a diagnostic feature of light chain amyloidosis (AL). MG of unknown significance (MGUS) in the general population increases with increasing age. Wild type transthyretin amyloidosis (ATTRwt) is a disease of elderly men and MGUS would be expected to co-exist with ATTRwt in 5-8% of cases. However, a higher than expected prevalence of MGUS in the ATTRwt population has been reported. We therefore sought to determine the prevalence of MGUS and abnormal free light chain ratio (κ/λ ratio) in a series of ATTRwt patients.
Methods: 123 patients (average age 76 +/- 8 yr, 4 female) with ATTRwt cardiomyopathy were seen over 10 years.
Results: 101 (82%) patients showed no evidence of MGUS. Of the 22 (18%) patients with MGUS, 9 (40.9%) had an abnormal κ/λ ratio (8/9 with kappa predominance). Of those without MGUS, 16 (15.8%) presented with abnormal κ/λ ratio (15/16 with kappa predominance). As renal impairment may disproportionately affect kappa levels, we compared serum creatinine levels in those with and without an abnormal κ/λ ratio. No significant difference was found.
Conclusions: MGUS was present in 18% of patients with ATTRwt cardiomyopathy, greater than 40% of whom also have an abnormal κ/λ ratio. This may cause diagnostic confusion with AL amyloidosis. Unlike AL amyloidosis, the abnormal κ/λ ratio in ATTRwt is almost exclusively kappa predominant. Renal impairment did not appear to account for elevated free kappa in this population even in the absence of MGUS.
Poster Hall, Hall C
Sunday, March 19, 2017, 9:45 a.m.-10:30 a.m.
Session Title: The Evolving World of LVADs, Transplant and Other Novel Discoveries
Abstract Category: 13. Heart Failure and Cardiomyopathies: Clinical
Presentation Number: 1294-295
- 2017 American College of Cardiology Foundation