Decoding Clot Waveform Analysis: Toward Better Understanding and Harmonization

Clot waveform analysis (CWA) extends routine coagulation assays (activated partial thromboplastin time [aPTT] and prothrombin time [PT]) by incorporating continuous optical monitoring to generate kinetic profiles of clot formation. This method provides both qualitative and quantitative information on hemostasis, with increasing evidence for its clinical utility in detecting factor deficiencies and characterizing thrombotic and bleeding disorders. Despite the growing body of evidence, translation of CWA into routine clinical practice remains limited.This review identifies three principal barriers: (1) variability arising from differences in optical detection methods (absorbance vs. transmittance), (2) interreagent variation even within the same analyzer platform, and (3) lack of a clear distinction between standard CWA, performed with commercially available reagents, and modified CWA, incorporating in-house adjustments. To address these challenges, we encourage adopting distinct nomenclature for detection modalities (CWA-A; A for absorbance and CWA-T; T for transmittance), establishing standardized reporting requirements including reagent and platform details, and establishing quality assurance frameworks for CWA.Standardization of terminology and reporting will enhance reproducibility, enable cross-study comparisons, and accelerate the clinical translation of CWA from the laboratory bench to the bedside.