Thromboelastography with Platelet Mapping Detects Platelet Dysfunction in Patients with Aneurysmal Subarachnoid Hemorrhage with Rebleeding

Figures & data

Figure 1 Explanation of TEG and TEG-PM. (A) TEG parameters: K, Angle, MA, EPL and LY30. (B), TEG-PM parameters: MA_Thrombin, MA_ADP/AA, and MA_Fibrin. R, reaction time to clot formation; K, clotting time until 20-mm amplitude is achieved; Angle, time to reach a maximum speed of initial clot formation.

Abbreviations: MA, maximum amplitude; EPL, percent of clot lysis 30 mins after MA; LY30, percent of amplitude decay 30 mins after MA; AA, arachidonic acid; ADP, adenosine diphosphate.

Table 1 Patient Characteristics

Variable	Value
Number of patients	245
Males, n (%)	79 (32.2)
Age, mean±SD	55.2±10.7
SBP on admission, mmHg, mean±SD	145.9±25.4
DBP on admission, mmHg, mean±SD	84.3±14.2
Aneurysm location
Anterior circulation, n (%)	232 (94.7)
Posterior circulation, n (%)	13 (5.3)
Aneurysm size
0–9.9 mm, n (%)	223 (91.0)
≥10 mm, n (%)	22 (9.0)
Hunt–Hess grade
I, n (%)	3 (1.2)
II, n (%)	176 (71.8)
III, n (%)	39 (15.9)
IV, n (%)	22 (9.0)
V, n (%)	5 (2.0)
Fisher grade
I, n (%)	2 (0.8)
II, n (%)	39 (15.9)
III, n (%)	128 (52.2)
IV, n (%)	76 (31.0)
Intracranial hematoma, n (%)	32 (13.1)
Death, n (%)	31 (12.7)

Abbreviations: SD, standard deviation; SBP, systolic blood pressure; DBP, diastolic blood pressure.

Table 2 Platelet Count and TEG-PM Parameters in Controls and Subarachnoid Hemorrhage Patients Stratified by Neurological Severity

	All aSAH	Severe SAH	Nonsevere SAH	UIA	P Values
					All aSAH versus UIA	Severe versus UIA	Severe versus Mild
Number of patients	245	27	218	32
PLT, k/μL, median (IQR)	192 (157–231.5)	173 (146–216)	194 (157–233.25)	176 (147–219.5)	0.261	0.704	0.088
R, min, median (IQR)	4.8 (4.0–5.6)	4.8 (4.3–6.5)	4.8 (4.0–5.6)	5.25 (4.23–6.10)	0.090	0.909	0.242
K, min, median (IQR)	1.7 (1.2–2.1)	2.0 (1.5–3.0)	1.65 (1.2–2.1)	1.7 (1.2–1.98)	0.615	0.046	0.029
Angle, °, median (IQR)	68.1 (62.4–73.05)	65.7 (53.4–69.8)	69.05 (63.25–73.2)	68.55 (64.78–72.83)	0.586	0.060	0.046
MA, mm, median (IQR)	64.2 (60.15–68)	62.5 (55.6–66.6)	64.55 (60.6–68.03)	63.45 (62.2–66.05)	0.554	0.334	0.098
EPL, %, median (IQR)	0.1 (0.1–1.55)	0.4 (0.1–1.0)	0.1 (0.1–1.93)	0.1 (0.1–0.75)	0.355	0.315	0.824
LY30, %, median (IQR)	0.1 (0.1–0.8)	0.1 (0.1–1.0)	0.1 (0.1–0.8)	0.1 (0.1–0.35)	0.198	0.144	0.471
AA inhibition, %, median (IQR)	21.5 (9.4–47.35)	84.7 (27.7–94.6)	19.5 (8.9–40.25)	11.6 (2.45–27.13)	0.013	<0.001	<0.001
ADP inhibition, %, median (IQR)	88.7 (59.75–96.8)	96.0 (83.8–100)	86.95 (54.8–96.35)	32.3 (15.4–51.75)	<0.001	<0.001	0.005

Abbreviations: TEG-PM, thrombelastography with platelet mapping; SAH, subarachnoid hemorrhage; UIA, unruptured intracranial aneurysms; PLT, platelet; IQR, interquartile range; R, reaction time to clot formation; K, clotting time until 20-mm amplitude is achieved; Angle, time to reach maximum speed of initial clot formation; MA, maximum amplitude; EPL, percent of clot lysis 30 mins after MA; LY30, percent of amplitude decay 30 mins after MA; AA, arachidonic acid; ADP, adenosine diphosphate.

Figure 2 Scatter plots showing the correlations between the degree of pathway inhibition and clinical grades. (A) AA inhibition was significantly correlated with Fisher grade (Spearman’s r=0.169, P=0.008); (B) ADP inhibition was significantly correlated with Fisher grade (Spearman’s r=0.233, P<0.001); (C) AA inhibition was significantly correlated with Hunt–Hess grade (Spearman’s r=0.264, P<0.001); (D) ADP inhibition was significantly correlated with Hunt–Hess grade (Spearman’s r=0.183, P=0.004).

Abbreviation: AA, arachidonic acid; ADP, adenosine diphosphate.

Table 3 Comparison of Baseline Demographic, Clinical Characteristics and TEG-PM Parameters Between Patients with and Without Rebleeding

	Rebleeding	Non-Rebleeding	P Values
No. of patients	35	210
Males, n (%)	12 (34.3)	67 (31.9)	0.780
Age, mean±SD	56.7±10.2	55.0±10.7	0.373
SBP on admission, mmHg, mean±SD	159.8±34.8	143.5±22.8	0.011
DBP on admission, mmHg, mean±SD	90.2±18.1	83.4±13.3	0.008
Aneurysm location			0.181
Anterior circulation, n (%)	31 (88.6)	201 (95.7)
Posterior circulation, n (%)	4 (11.4)	9 (4.3)
Aneurysm size			1.000
0–9.9 mm, n (%)	32 (91.4)	191 (91.0)
≥10 mm, n (%)	3 (8.6)	19 (9.0)
Hunt–Hess grade			0.034
I-III, n (%)	27 (77.1)	191 (91.0)
IV-V, n (%)	8 (22.9)	19 (9.0)
Fisher grade			0.015
I, n (%)	0 (0)	2 (1.0)
II, n (%)	1 (2.9)	38 (18.1)
III, n (%)	16 (45.7)	112 (53.3)
IV, n (%)	18 (51.4)	58 (27.6)
Intracranial hematoma, n (%)	11 (31.4)	21 (10.0)	0.001
Death, n (%)	19 (54.2)	12 (5.7)	<0.001
PLT, k/μL, median (IQR)	191 (152–244)	193 (157.8–231)	0.917
R, min, median (IQR)	5 (3.8–5.7)	4.8 (4–5.6)	0.890
K, min, median (IQR)	1.7 (1.2–2.2)	1.7 (1.2–2.1)	0.936
Angle, °, median (IQR)	67.8 (60.1–74.2)	68.5 (62.7–73.0)	0.839
MA, mm, median (IQR)	65.5 (60.1–68.3)	64.2 (60.2–67.8)	0.642
EPL, %, median (IQR)	0.1 (0.1–1.1)	0.1 (0.1–1.8)	0.173
LY30, %, median (IQR)	0.1 (0.1–0.4)	0.1 (0.1–0.9)	0.250
AA inhibition, %, median (IQR)	44.9 (24.6–86.5)	19.1 (8.1–42.4)	<0.001
ADP inhibition, %, median (IQR)	97.0 (90.7–100)	85.1 (52.3–96.0)	<0.001

Abbreviations: TEG-PM, thrombelastography with platelet mapping; SD, standard deviation; SBP, systolic blood pressure; DBP, diastolic blood pressure; PLT, platelet; IQR, interquartile range; R, reaction time to clot formation; K, clotting time until 20-mm amplitude is achieved; Angle, time to reach maximum speed of initial clot formation; MA, maximum amplitude; EPL, percent of clot lysis 30 mins after MA; LY30, percent of amplitude decay 30 mins after MA; AA, arachidonic acid; ADP, adenosine diphosphate.

Table 4 Multivariate Analysis for Risk Factors of Rebleeding

	OR	95% CI	P Values
SBP on admission	1.020	1.000–1.041	0.050
DBP on admission	1.002	0.967–1.038	0.910
Hunt–Hess grade	0.871	0.470–1.611	0.659
Fisher grade	2.571	0.971–6.808	0.057
AA inhibition	1.016	1.001–1.030	0.037
ADP inhibition	1.042	1.011–1.075	0.008

Abbreviations: OR, odds ratio; CI, confidence interval; SBP, systolic blood pressure; DBP, diastolic blood pressure; AA, arachidonic acid; ADP, adenosine diphosphate; IQR, interquartile range.