Effects of dabigatran, rivaroxaban, and apixaban on fibrin network permeability, thrombin generation, and fibrinolysis

Figures & data

Table 1. Clinical characteristics of patients.

	Dabigatran (n = 23)	Rivaroxaban (n = 26)	Apixaban (n = 20)	Warfarin (n = 27)	p-Values
Female gender (n (%))	7 (30)	9 (35)	9 (45)	12 (44)	0.67
Age (years)	67 (58–70)	69 (62–76)	76 (67–77)	54 (46–64)	<0.01
Weight (kg)	84 (74–97)	84 (81–89)	82 (66–92)	86 (78–97)	0.69
Smokers/ex-smokers (%)	0/57	12/31	22/30	22/41	0.48
Diabetes mellitus (n (%))	2 (9)	5 (19)	5 (25)	1 (4)	0.13
Hypertension (n (%))	18 (78)	16 (62)	12 (60)	12 (44)	0.11
Myocardial infarction (n (%))	3 (13)	2 (8)	3 (15)	3 (11)	0.88
Heart failure (n (%))	4 (17)	2 (8)	2 (10)	2 (7)	0.64
Ischemic stroke/Transitory ischemic attack (n (%))	4 (17)	8 (31)	2 (10)	1 (4)	<0.05
Venous thromboembolism (n (%))	0	0	1 (5)	23 (85)	<0.01
Aspirin treatment (n (%))	0	2 (8)	0	1 (4)	–
Hemoglobin concentration (g/L)	140 (133–149)	144 (136–154)	138 (127–149)	145 (136–156)	0.11
Platelet count (×10^9/L)	218 (194–237)	211 (188–233)	211 (190–261)	242 (221–302)	0.02
eGFR (Cockroft-Gault, ml/min)	93 (68–106)	87 (68–115)	78 (60–102)	116 (80–160)	<0.01

Values presented as median and quartiles or percentages.

Figure 1. Fibrin network permeability (Ks—see method section—clotting triggered with TF) in samples from patients treated with dabigatran (n = 23), rivaroxaban (n = 26), apixaban (n = 20), and warfarin (n = 27)—results presented as Ks % of normal Pool plasma (NPP). All treatment groups had higher permeability than commercial NPP (p < 0.01). Differences between groups evaluated with Kruskal Wallis test followed by Dunn’s post-hoc testing if significant. p-Values represent the significance level of post-hoc testing.

Table 2. Results from tests of hemostasis.

	Dabigatran	Rivaroxaban	Apixaban	Warfarin	p-Values
Fibrin network permeability (Ks % of control)	354 (282–404)	188 (147–221)	119 (72–174)	218 (180–289)	0.03
TG lag time (min)	5.2 (4.7–6.2)	3.5 (3.4–3.9)	3.9 (3.4–4.5)	4.3 (3.8–5.8)	<0.01
TG peak thrombin (nmol/L)	N/A	177 (144–205)	199 (186–220)	97 (76–144)	<0.01
TG ETP (nmol/L × min)	N/A	1726 (1471–1854)	1887 (1600–2081)	690 (493–869)	<0.01
TAT (µg/L)	2.6 (1.9–3.5)	2.3 (1.9–3.3)	2.0 (1.8–3.5)	2.9 (2.5–3.2)	0.28
Turbidimetry lag time (s)	971 (875–1163)	245 (212–299)	251 (239–275)	Not determined	<0.01
Turbidimetry CFR (×10^−3AU/s)	0.31 (0.25–0.40)	1.0 (0.9–1.2)	1.0 (0.8–1.1)	Not determined	<0.01
Turbidimetry max absorbance (AU)	0.32 (0.26–0.38)	0.38 (0.34–0.42)	0.43 (0.33–0.49)	Not determined	<0.01
Turbidimetry lysis time (s)	1038 (912–1236)	900 (759–999)	930 (795–1185)	Not determined	0.04
D-dimer (mg/L)	<0.2 (<0.2–0.26)	0.24 (<0.2–0.49)	0.32 (0.20–0.59)	Not determined	<0.01
Fibrinogen (g/L; ref 2.0–4.2)	3.5 (3.3–3.9)	3.9 (3.8–4.4)	4.3 (3.8–5.2)	3.8 (3.2–4.8)	0.01
PT-INR (ref <1.2)	1.1 (1.0–1.1)	1.0 (1.0–1.1)	1.0 (1.0–1.1)	2.7 (2.0–3.4)	<0.01
aPTT (s; ref 20–30)	45 (41–50)	35 (34–37)	36 (32–39)	48 (40–58)	0.66
LC-MS/MS (ng/mL)	52 (33–79)	33 (21–45)	77 (62–107)	N/A	<0.01

Patients treated with dabigatran (n = 23), rivaroxaban (n = 26), apixaban (n = 20), and warfarin (n = 27). Values presented as median and quartiles. Peak thrombin and ETP data were not analyzed in dabigatran treated patients due to interaction between dabigatran and α₂-macroglobulin-thrombin complex in the calibration sample as previously described [48–52]. Turbidimetric measurements or determination of D-dimer concentrations in plasma were not performed in samples from warfarin treated patients.

Figure 2. Scanning electronic microscope images showing the fibrin network structure in selected dabigatran- (a,b), apixaban- (c,d), rivaroxaban- (e,f), and warfarin-treated (g,h) patients with different fibrin network permeability (Ks) as well as NPP for comparison (i). The respective DOAC concentration or PT-INR is provided below each image.

Figure 3. Fibrin network permeability in commercial NPP spiked with eight different concentrations of DOAC (13–1000 ng/mL) and in PPP from warfarin-treated patients with PT-INR values ranging from 1 to 9 (n = 7; each sample concentration analyzed once). Results presented as Ks % of NPP. Expected range of concentration [10th–90th percentile (median)] at the trough for each DOAC: Dabigatran (150 mg × 2) 40–215 (93), apixaban (5 mg × 2) 41–230 (103), rivaroxaban (20 mg × 1) 6–239 (32) [10–12].

Figure 4. CAT (see method section—thrombin generation after clotting triggered with TF) lag time (A), ETP (B), and peak thrombin (C) in samples from patients treated with dabigatran (n = 23), rivaroxaban (n = 26), apixaban (n = 20), and warfarin (n = 26). Peak thrombin and ETP data were not analyzed in dabigatran-treated patients due to the interaction between dabigatran and α₂-macroglobulin-thrombin complex in the calibration sample as previously described [48–52]. Differences between groups evaluated with Kruskal Wallis test followed by Dunn’s post-hoc testing if significant. p-Values represent the significance level of post-hoc testing.

Figure 5. Results from the turbidimetric clotting and lysis assay (see method section—clotting triggered with thrombin) in samples from patients treated with dabigatran (n = 23), rivaroxaban (n = 26), and apixaban (n = 20). Commercial NPP was used for comparison (five repeated runs). (A) lag time, (B) CFR, (C) max absorbance, and (D) lysis time. Differences between groups were evaluated with one-way ANOVA followed by Tukey’s post-hoc testing if significant. p-Values represent the significance level of post-hoc testing.