The association of neutrophil-to-lymphocyte ratio and delayed cerebral ischemia in patients with aneurysmal subarachnoid hemorrhage: possible involvement of cerebral blood perfusion

Figures & data

Table 1 Baseline characteristics according to the prevalence of DCI

	Total (n=122)	DCI (n=43)	non-DCI (n=79)	P-value
Demographics
Sex (male)	48 (39.3)	26 (60.5)	22 (27.8)	<0.001
Age (years)	55.3 (10.6)	55.0 (10.8)	55.5 (10.6)	0.789
Clinical feature
Time-to-admission (hrs)	39.5 (18.6)	37.8 (19.9)	40.6 (17.8)	0.502
High grade  (HH grades IV–V)	24 (19.7)	20 (46.5)	4 (5.1)	<0.001
Massive hemorrhage (Fisher grades III–IV)	109 (89.3)	43 (100)	65 (82.3)	0.008
Hydrocephalus	14(11.5)	11 (25.6)	3 (3.8)	<0.001
Hypertension	52 (42.6)	22 (51.2)	30 (38.0)	0.159
Diabetes	6(4.9)	1(2.3)	5(6.3)	0.59
Smoker	37(30.3)	17(39.5)	20(25.3)	0.103
Aneurysm location (posterior circulation)	11(9)	3 (7.0)	8 (10.1)	0.803
Initial laboratories
WBC count (×10^9/L)	11.3 (4.2)	13.2 (4.8)	10.3 (3.4)	<0.001
NC (×10^9/L)	9.5 (4.0)	11.5 (4.5)	8.5 (3.3)	<0.001
LC (×10^9/L)	1.1 (0.54)	1.0 (0.64)	1.2 (0.48)	0.074
NLR	10.7 (8.2)	14.8 (10.7)	8.4 (5.3)	<0.001

Notes: Data were expressed as mean (SD) for continuous variables and n (%) for categorical variables. High grade was defined as HH grades IV–V. Massive hemorrhage was defined as Fisher grades III–IV.

Abbreviations: DCI, delayed cerebral ischemia; HH Grade, Hunt–Hess Grade; WBC, white blood cell; NC, neutrophil count; LC, lymphocyte count; NLR, neutrophil-to-lymphocyte ratio.

Table 2 Logistic regression analysis according to the occurrence of DCI

Independent variable	Unadjusted		Adjusted
	OR (95% CI)	P-value	OR (95% CI)	P-value
WBC count	1.19(1.08–1.32)	<0.001	1.17(1.00–1.37)	0.056
NC	1.22(1.10–1.36)	<0.001	1.22(1.03–1.45)	0.022
LC	0.48(0.22–1.08)	0.077	0.37(0.11–1.21)	0.100
NLR	1.13(1.06–1.20)	<0.001	1.16(1.05–1.27)	0.002

Note: Variables were adjusted by baseline characteristics including sex, age, Hunt–Hess grade, hydrocephalus, and hypertension.

Abbreviations: DCI, delayed cerebral ischemia; WBC, white blood cell; NC, neutrophil count; LC, lymphocyte count; NLR,neutrophil-to-lymphocyte ratio.

Table 3 WBC count in predicting the occurrence of DCI

Independent variable	Unadjusted		Adjusted
	OR (95% CI)	P-value	OR (95% CI)	P-value
Higher WBC count	4.67(2.11–10.32)	<0.001	4.38(1,37–13.96)	0.013
Higher NC	3.16(1.34–7.46)	0.01	2.86(0.858–9.56)	0.087
Lower LC	2.93(1.02–8.42)	0.043	2.22(0.53–9.32)	0.275

Notes: Higher WBC count was defined as WBC >11.5×10⁹/L. Higher NC count was defined as NC >7.5×10⁹/L. Lower LC count was defined as LC <1.5×10⁹/L. Variables were adjusted by baseline characteristics including sex, age, Hunt–Hess grade, hydrocephalus, and hypertension.

Abbreviations: DCI, delayed cerebral ischemia; WBC, white blood cell; NC, neutrophil count; LC, lymphocyte count.

Table 4 CTP parameters in predicting the occurrence of DCI

Independent variable	Unadjusted		Adjusted
	OR (95% CI)	P-value	OR (95% CI)	P-value
mCBF	0.70(0.61–0.79)	<0.001	0.75(0.63–0.89)	0.001
mCBV	0.15 (0.05–0.44)	<0.001	0.53(0.12–2.35)	0.405
MTT mTTP	2.85(1.98–4.11) 1.80(1.33–2.44)	<0.001 <0.001	2.85(1.69–4.81) 1.67(1.04–2.70)	<0.001 0.036

Note: Variables were adjusted by baseline characteristics including sex, age, Hunt–Hess grade, hydrocephalus, and hypertension.

Abbreviations: DCI, delayed cerebral ischemia; mCBF, mean cerebral blood flow; mCBV, mean cerebral blood volume; MTT, mean transit time; mTTP, mean time to peak.

Figure 1 ROC analysis for the prediction of DCI and the correlation between NLR and CTP parameters. (A) The curve showed the predictive values of WBC, NC, LC, and NLR for the occurrence of DCI. The AUC of WBC, NC, LC, and NLR was 0.688 (P=0.001), 0.708 (P<0.001), 0.639 (P=0.011), and 0.722 (P<0.001), respectively. (B) NLR was significantly correlated with mCBF (ρ = −0.290, P=0.001), MTT (ρ =0.340, P<0.001), and mTTP (ρ =0.196, P=0.031). No correlation was found between NLR and mCBV (ρ =−0.117, P=0.198). (C) A case of aSAH diagnosed by brain CT scan. CTA showed a right PcomA aneurysm. CTP was performed 4 days after SAH showing a decrease of CBF and CBV and a prolonged MTT and TTP of the right hemisphere.

Abbreviations: ROC, receiver operating characteristic curve; DCI, delayed cerebral ischemia; WBC, white blood cell; NC, neutrophil count; LC, lymphocyte count; NLR, neutrophil-to-lymphocyte ratio; AUC, area under the curve; CBF, cerebral blood flow; CBV, cerebral blood volume; MTT, mean transit time; TTP, time to peak.