Background: Carpal tunnel syndrome (CTS) is considered an early sign of cardiac amyloidosis (CA) because amyloid deposition is often confirmed in the tenosynovium removed during carpal tunnel release (CTR); however, the prevalence of concomitant CA is unclear.
Methods and results: We prospectively examined 700 patients who underwent CTR and evaluated amyloid deposition after tenosynovium removal. Amyloid deposition was observed in 261 (37%) patients, who were significantly older and predominantly male (P<0.05). Of them, 120 agreed to cardiac screening. We performed 99 mTc-labeled pyrophosphate (99 mTc-PYP) scintigraphy in 12 patients who met either of the following criteria: (1) interventricular septal diameter (IVSd) ≥14 mm or (2) 12 mm ≤ IVSd < 14 mm with above-normal limits in high-sensitivity cardiac troponin T (hs-cTnT). Six patients (50%) had positive findings on 99 mTc-PYP scintigraphy and were diagnosed with wild-type transthyretin CA. Concomitant CA was observed in 6/120 (5%) CTR patients with amyloid deposition and 50% (6/12) in patients with left ventricular hypertrophy (≥12 mm) with increased hs-cTnT levels.
Conclusions: Amyloid deposition was frequently observed in the removed tenosynovium of elderly men with CTS. Cardiac screening may be useful for early diagnosis of CA in patients undergoing CTR with amyloid deposition.
Keywords: Amyloid; Cardiac amyloidosis; Carpal tunnel release; Carpal tunnel syndrome; Tenosynovium.