Transthyretin cardiac amyloidosis (ATTR-CA) is a restrictive cardiomyopathy caused by the abnormal deposition of transthyretin (TTR) in the myocardial interstitium, which often manifests as heart failure, atrial fibrillation, and conduction disorders. The significant heterogeneity of its clinical presentation poses a major challenge to accurate diagnosis. The dissociation of the TTR tetramer is the key initiating step of amyloid deposition in ATTR-CA, but the TTR tetramer is not currently included among the clinically applied biomarkers. This article systematically reviews the conventional biomarkers for ATTR-CA and focuses on discussing the potential value of the TTR tetramer as a novel indicator. Investigating the concentration, peak profile, and dissociation rate of the TTR tetramer is of great value for achieving early identification, risk stratification, and prognostic judgment of ATTR-CA.