Prevalence of cardiac amyloidosis in patients undergoing carpal tunnel release with amyloid deposition in removed tenosynovium

Abstract Background Carpal tunnel syndrome (CTS) is an early symptom and important clinical indicator for the diagnosis of cardiac amyloidosis. Amyloid deposition in removed tenosynovium during carpal tunnel release (CTR) is often confirmed; however, the prevalence of concomitant cardiac amyloidosis is not yet understood. Purpose This study aimed to evaluate the prevalence of amyloid deposition in removed tenosynovium in patients who underwent CTR and to clarify the prevalence of concomitant cardiac amyloidosis in patients who had amyloid deposition in removed tenosynovium. Methods Overall, 669 patients who underwent CTR were prospectively examined and evaluated for amyloid deposition after tenosynovium removal. Invitation and proposal letters for cardiac screening were sent to patients with amyloid deposition. Electrocardiography, echocardiography, and biomarkers were evaluated to assess the likelihood of cardiac amyloidosis. Results Amyloid deposition was observed in 261 (39%) patients, who were significantly older and predominantly male (p<0.05). Among them, 111 patients (mean age; 70.8 ± 7.3 years old; men: 55%) agreed to cardiac screening. 99mTc-labeled pyrophosphate (99mTc-PYP) scintigraphy was performed in 12 patients who met the following criteria: 1) interventricular septum diameter (IVSd) ≥14 mm or 2) 12 mm ≤ IVSd <14 mm with above-normal limits in high-sensitivity cardiac troponin T (hs-cTnT; >0.014 ng/mL). Six patients (50%) had positive findings on 99mTc-PYP scintigraphy and were diagnosed with wild-type transthyretin cardiac amyloidosis with Mayo prognostic stage I. The prevalence of concomitant cardiac amyloidosis was observed in 6/111 (5.4%) CTR patients with amyloid deposition and 50% (6/12) in patients with left ventricular hypertrophy (≥12 mm) with increased hs-cTnT levels. Conclusion Amyloid deposition in removed tenosynovium was frequently observed in elderly men with CTS. Cardiac screening may be useful for the early diagnosis of cardiac amyloidosis in patients undergoing CTR with amyloid deposition. This knowledge should be shared with orthopedic surgeons and cardiologists for the early diagnosis of cardiac amyloidosis.Flowchart of participant selectionGraphical Abstract