Optimal wavelength for the clot waveform analysis: Determination of the best resolution with minimal interference of the reagents

Abstract

Introduction:Clot waveform analysis (CWA), a new methodology to assess coagulation process, can be usefully applied in various clinical settings. However, its clinical use is limited mainly because of the absence of standardization. No consensus exists regarding the wavelengths at which CWA has to be performed what is crucial for the sensitivity of the CWA. Objectives:The primary aim of this study is to determine which wavelength is the most sensitive and specific for CWA. Interindividual baseline absorbance will also be assessed as the impact of reagents from the intrinsic, extrinsic, and common coagulation pathway will be determined.Methods: Plasma samples were screened at wavelengths from 280 to 700 nm to provide absorbance spectra in clotted and nonclotted plasma. The interindividual variability of baseline absorbance was obtained by screening plasma from 50 healthy individuals at 340, 635, and 671 nm. The inner-filter effect of reagents was assessed in plasma or serum when appropriate at the same wavelengths. The reagents were those commonly used for activated partial thromboplastin time, prothrombin time, thrombin time, and dilute Russell's viper venom time.Results: Clotted plasma has higher absorbance value than nonclotted plasma (P < 0.01). The absorbance of all type of samples is higher at 340 nm than at >600 nm (P < 0.01). The interindividual variability at the different wavelengths was around 25%. However, except with the STA®-CKPrest® and STA®-NeoPTimal®, the reagents do not have a significant effect on the baseline absorbance. Conclusions:Wavelengths above 650 nm are recommended to perform CWA. Most of the commercialized reagents can be used for CWA. | 317EVRARD Et Al.

Update on the Clot Waveform Analysis

“…13 It was reported that the wavelengths above 650 nm are recommended to perform CWA and most of the commercialized reagents can be used for CWA. 14 …”

“…13 It was reported that the wavelengths above 650 nm are recommended to perform CWA and most of the commercialized reagents can be used for CWA. 14 Figure 1. The hemostatic system including the clotting cascade, thrombin burst, and the enhancement of clotting activation by phospholipid.…”

Assessment of acquired activated protein C resistance with the FibWave and comparison with the ETP‐based APC resistance

“…According to our data, the fibrinogen level is positively correlated with the FW‐Delta, and this observation is not surprising but revealed that the FibWave is able, to a certain degree, to inform on the level of fibrinogen in a particular patient (Figure 1). 36 …”

“…As Protac is known to activate FV and FVIII within the first 3 to 5 minutes of incubation, an incubation period of 10 minutes was fixed to avoid hazardous fluctuations of activated FV and FVIII 24 . The coagulation process is triggered by the addition of 20 µL of CaCl 2 at 100 mmol/L, and the turbidity is monitored during 45 minutes at 671 nm as previously described 25 . The ETP‐based APC resistance has been performed as previously reported using standardized and validated procedure developed by QUALIblood s.a. (Namur, Belgium) 26 …”

Simultaneous assessment of DOACs effect on clot formation and fibrinolysis with the FibWave

“…The exclusion criteria and the protocol for venipuncture were the same as previously. 6 The parameters extracted from the clot formation were (a) the The FW-Delta (P < .05), FW-Max 1 (P < .05), the FW-Max 2 (P < .05), and the FW-Min 2 (P < .05) were higher in women using CHC and the FW-Ttpeak was reduced (P > .05) compared with men. (Continues)…”