Cardiac amyloidosis not uncommon in patients with prior surgery for carpal tunnel syndrome

Early-stage transthyretin cardiac amyloidosis (CA) has been diagnosed in nearly 5 percent of patients with prior surgery for bilateral carpal tunnel syndrome (CTS), reveals a recent study.

“The clinical yield was higher (>1 in 5) when focusing on nonobese men ≥70 years, showing potential for systematic screening,” the researchers said.

A team of researchers identified individuals aged 60‒85 years with prior CTS surgery, where the first procedure on the second wrist was performed 5‒15 years earlier, using national registries. They sent invitations to participate in the study by mail.

Based on international recommendations, the initial cardiac evaluation included echocardiography, ^99mtechnetium-pyrophosphate scintigraphy, and assessment of monoclonal proteins in serum and urine.

Of those who were sent invitations, 250 (35.7 percent, median age 70.4 years, 50 percent female) opted to participate in the study. Twelve patients (4.8 percent, 95 percent confidence interval [CI], 2.5‒8.2) had a CA diagnosis, all of which were wild-type transthyretin amyloidosis (ATTRwt).

ATTRwt prevalence was 8.8 percent (95 percent CI, 4.5‒15.2; b=11) in men and 21.2 percent (95 percent CI, 11.1‒34.7) in male participants aged ≥70 years with a body mass index <30 kg/m². Except for two patients, all of those diagnosed with ATTRwt were in the lowest disease severity score (Mayo score).

“Bilateral CTS is a common extracardiac manifestation of amyloidosis and usually predates overt CA by several years,” the researchers said. “Screening studies on patients undergoing CTS surgery have shown a low yield of CA (2.0 percent), but high prevalence of amyloid in the carpal ligament.”