Wild-Type Transthyretin Amyloidosis: A Prevalent and Underdiagnosed Cause of Heart Failure With Preserved Ejection Fraction.

ABSTRACT

Cardiac amyloidosis is an infiltrative disease characterized by the extracellular deposition of misfolded protein in the myocardium, leading to increased stiffness and an eventual restrictive cardiomyopathy. The slow onset of symptoms and overlap with other cardiomyopathies make prompt diagnosis a challenge. Clinicians should be alerted and include amyloidosis in their differential diagnosis, particularly in patients with heart failure with preserved ejection fraction, unexplained left ventricle hypertrophy, particularly in those shown intolerance to previous antihypertensive medication, and early orthopedic manifestations of the disease such as carpal tunnel syndrome and spinal stenosis. The workup requires the exclusion of monoclonal gammopathies and technetium-99m pyrophosphate nuclear scintigraphy (99mTc-PYP) studies with single-photon emission computerized tomography (SPECT) imaging. Several therapies are now available and can prolong life with significantly improved quality of life, particularly when the diagnosis of amyloidosis is made early. We present the case of a 77-year-old with a delayed diagnosis by five years to highlight the need for heightened clinical suspicion and an appropriate diagnostic algorithm for cardiac amyloidosis.