Abstract 571 The dilute Russel´s viper venom time – a helpful tool to detect direct oral anticoagulants Observations in a real life setting

Clin Res Cardiol (2021)
DOI DOI https://doi.org/10.1007/s00392-021-01843-w

The dilute Russel´s viper venom time – a helpful tool to detect direct oral anticoagulants Observations in a real life setting

T. Klöter¹, M. Metze¹, T. Siegemund², A. Siegemund², U. Laufs¹, S. Petros²

¹Klinik und Poliklinik für Kardiologie, Universitätsklinikum Leipzig, Leipzig; ²Interdisziplinäre Internistische Intensivmedizin, Universitätsklinikum Leipzig, Leipzig;

Background. Real world data regarding the effect of direct oral anticoagulants (DOACs) on the dilute Russel`s viper venom time (dRVVT) is scarce. Yet the dRVVT may be helpful to detect residual antithrombotic activity in emergency settings when drug-specific plasma level assays are not readily available.

Objective. The study aims to evaluate the sensitivity and specificity of dRVVT for different DOAC plasma levels.

Methods. In total, 80 patients were recruited – 20 patients for each approved DOAC (apixaban, edoxaban, rivaroxaban and dabigatran). Blood plasma was sampled before (baseline), 6 and 12 hours after DOAC-intake and at plasma peak time. DRVVT was measured using the LA1 screening assay for lupus anticoagulant (Siemens healthineers®). Plasma levels were measured by calibrated anti-Xa or anti-IIa tests. Additionally, standard coagulation assays such as activated partial thromboplastin time (aPTT) and prothrombin time (PT) were performed.

Results. All DOACs significantly prolonged the dRVVT. The effects were more pronounced in higher DOAC plasma levels. The area under the receiver operating characteristic (ROC) curve regarding a plasma level cut-off of 30 ng/ml was 0.95 (95% confidence interval (CI) 0.899 to 1.00) for apixaban, 0.99 (95% CI 0.964 to 1.00) for edoxaban, 0.98 (95% CI 0.942 to 1.00) for rivaroxaban and 0.97 (95% CI 0.937 to 1.00) for dabigatran.

Table 1. Sensitivity and specificity of dRVVT / PT / aPTT thresholds to predict different DOAC plasma levels.

		Plasma level
		30-49 ng/ml		50-99 ng/ml		≥100 ng/ml
Parameter	DOAC	Sensitivity %	Specificity %	Sensitivity %	Specificity %	Sensitivity %	Specificity %
dRVVT >40 sec	Apixaban	86.7	84.6	95.7	80.8	100.0	84.6
	Dabigatran	100.0	52.5	100.0	52.5	100.0	52.5
	Edoxaban	100.0	72.7	100.0	72.7	100.0	72.7
	Rivaroxaban	100.0	68.4	100.0	68.4	98.1	68.4
PT <70%	Apixaban	6.3	92.3	4.5	92.3	6.3	92.3
	Dabigatran	0.0	97.4	5.8	100.0	6.7	100.0
	Edoxaban	0.0	95.2	14.3	100.0	54.8	100.0
	Rivaroxaban	0.0	94.7	14.3	100.0	28.9	100.0
aPTT >37 sec	Apixaban	6.3	96.2	4.5	96.2	0.0	96.2
	Dabigatran	12.5	92.3	58.8	92.3	100.0	92.3
	Edoxaban	50.0	100.0	7.1	100.0	30.9	100.0
	Rivaroxaban	0.0	94.7	0.0	94.7	32.7	94.7

DRVVT: dilute Russel`s viper venom time. PT: prothrombin time. APTT: activated partial thromboplastin time. DOAC: direct oral anticoagulant.

Conclusion. We provide real world data regarding the effect of DOACs on the dRVVT. Our study underlines the dose dependent sensitivity and specificity of dRVVT after DOAC-intake in all approved DOACs, while relevant plasma levels do not change PT or aPTT. When dedicated anti-Xa or anti-IIa tests are not available or the specific DOAC is unknown, the dRVVT can be a helpful clinical tool to rule out relevant antithrombotic plasma activity caused by DOACs.

Keywords
Direct oral anticoagulants, dilute Russel`s viper venom time, plasma level.

https://dgk.org/kongress_programme/jt2021/aP603.html