Cardiac amyloidosis after lumbar spinal stenosis surgery - a comprehensive prospective cohort study

Background Wild-type transthyretin (ATTRwt) amyloidosis is underdiagnosed and generally diagnosed with manifest cardiac involvement. Lumbar spinal stenosis (LSS) might be an early sign of systemic transthyretin amyloidosis and a possible screening target for early diagnosis. ObjectivesTo assess the prevalence of cardiac amyloidosis (CA) 6 years post-LSS surgery, among patients with transthyretin amyloid deposits in ligamentum flavum. Methods Twenty-one patients who had surgery for LSS in 2016-2018 and grade 3-4 ATTR amyloid deposits in ligamentum flavum were followed up in 2022-2023, including biomarkers, echocardiography, cardiac magnetic resonance (CMR) and nuclear imaging. Results At follow-up, median age was 79 years, 16% (3/19) displayed cardiac uptake on scintigraphy consistent with ATTR-CA. Forty-eight percent (10/21) had a history of other tenosynovial conditions associated with ATTRwt. We observed a small increase in tissue characteristics using CMR, and a decrease in left ventricular global longitudinal strain and left atrial strain on echocardiography. Conclusions In this prospective cohort study, 16% were diagnosed with ATTRwt cardiomyopathy, six years following surgery for LSS. History of other tenosynovial conditions associated with ATTRwt amyloidosis was common. These findings strengthen the hypothesis that LSS is a possible manifestation of ATTRwt amyloidosis and that in selected patients with LSS, cardiac follow-up is of value.