Direct versus Bridging Mechanical Thrombectomy in Elderly Patients with Acute Large Vessel Occlusion: A Multicenter Cohort Study

Figures & data

Figure 1 Flow chart of the patient inclusion steps.

Table 1 Comparison of Baseline Characteristics Between Direct Mechanical Thrombectomy (MT) and Bridging MT Patients

Characteristics	Total (n=482)	BMT (n=187)	DMT (n=295)	P-value
Age, median (IQR), year	73 (69–78)	72 (68-78)	73 (69-78)	0.791
Male (n, %)	259 (53.73)	87 (46.52)	172 (58.31)	0.012
Medical history (n, %)
Hypertension	309 (64.11)	115 (61.50)	194 (65.76)	0.342
Diabetes mellitus	97 (20.12)	36 (19.25)	61 (20.68)	0.703
Dyslipidemia	34 (7.05)	18 (9.63)	16 (5.42)	0.079
Coronary heart disease	108 (22.41)	46 (24.60)	62 (21.02)	0.358
Atrial fibrillation	221 (45.85)	85 (45.45)	136 (46.10)	0.890
Prior stroke	106 (21.99)	33 (17.65)	73 (24.75)	0.067
Current smoking	348/391 (89.00)	138/155 (89.03)	210/236 (88.98)	0.988
SBP, median (IQR), mmHg	147 (133–161)	146 (133–165)	148 (132–160)	0.980
NIHSS score, median (IQR)	17 (13–22)	17 (13–21)	18 (13–23)	0.084
Serum glucose, median (IQR)	7.0 (5.9–9.2)	7.1 (6.0–9.1)	7.0 (5.8–9.3)	0.864
WBC count, median (IQR)	7.7 (6.3–9.8)	7.5 (6.4–9.9)	7.8 (6.3- 9.7)	0.932
Platelet count, median (IQR)	190 (152–232)	191 (156–232)	190 (152–232)	0.525
INR, median (IQR)	1.02 (0.96–1.10)	1.01 (0.95–1.10)	1.03 (0.97–1.10)	0.224
Serum creatinine, median (IQR)	71.0 (60.4–83.3)	72.0 (60.0–84.5)	71.0 (60.6–83.0)	0.996
ASPECTS, median (IQR)	10 (7–10)	10 (7–10)	10 (7–10)	0.213
Occlusion site (n, %)
Anterior circulation	392 (81.33)	158 (84.49)	234 (79.32)	0.156
Posterior circulation	90 (18.67)	29 (15.51)	61 (20.68)
Good collaterals (n, %)	109/206 (52.91)	37/75 (49.33)	72/131 (54.96)	0.436
TOAST classification (n, %)
Large artery atherosclerosis	198/480 (41.25)	75/186 (40.32)	123/294 (41.84)	0.551
Cardioembolism	217/480 (45.21)	89/186 (47.85)	128/294 (43.54)
Other or unknown etiology	65/480 (13.54)	22/186 (11.83)	43/294 (14.63)
Treatment (n, %)
Preoperative antiplatelet agents	81 (16.80)	26 (13.90)	55 (18.64)	0.175
Preoperative anticoagulants	17 (3.53)	1 (0.53)	16 (5.42)	0.004*
General anesthesia	184 (38.17)	74 (39.57)	110 (37.29)	0.615
Stent retriever	426 (88.38)	162 (86.63)	264 (89.49)	0.340
Aspiration catheter	86 (17.84)	47 (25.13)	39 (13.22)	0.001
Intra-arterial thrombolysis	44 (9.13)	14 (7.49)	30 (10.17)	0.319
Balloon angioplasty	79 (16.39)	35 (18.72)	44 (14.92)	0.272
Stenting	63 (13.07)	25 (13.37)	38 (12.88)	0.877
Intraoperative heparin	231 (47.93)	60 (32.09)	171 (57.97)	<0.001
Infusion of GP IIb/IIIa inhibitor	205 (42.53)	74 (39.57)	131 (44.41)	0.296
OTD time, median (IQR), min	90 (50–140)	90 (53–140)	90 (48–144)	0.583
Drip and ship (n, %)	131 (27.18)	51 (27.27)	80 (27.12)	0.970

Notes: Good collaterals: American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology≥2; *Represents Fisher’s exact test.

Abbreviations: DMT, direct mechanical thrombectomy; BMT, bridging mechanical thrombectomy; SBP, systolic blood pressure; NIHSS, National Institutes of Health Stroke Scale; WBC, white blood cell count; INR, international normalized ratio; ASPECTS, Alberta Stroke Program Early CT Score; OTD, symptom onset to door.

Table 2 Univariate Analysis of Outcomes in the Direct Mechanical Thrombectomy (MT) and Bridging MT Patients

Outcomes	BMT	DMT	OR/β (95% CI)	P-value
Efficacy outcome
mRS at 90 d, median (IQR)	4 (1–5)	4 (1–5)	0.03738	0.858
mRS 0–1 at 90 d	67 (35.83)	101 (34.24)	0.932 (0.635–1.368)	0.721
mRS 0–2 at 90 d	71 (37.97)	113 (38.31)	1.014 (0.696–1.479)	0.941
mRS 0–3 at 90 d	86 (45.99)	144 (48.81)	1.120 (0.776–1.617)	0.546
Change in NIHSS score at 24 h, median (IQR)	−2 (−6, 0)	−2 (−7, 0)	−1.56836	0.045
Change in NIHSS score at 7 d, median (IQR)	−9 (−14, −3)	−9 (−14, −4)	−1.12063	0.275
Successful recanalization	163 (87.17)	258 (87.46)	1.027 (0.592–1.779)	0.925
OTP time, median (IQR), min	255 (199–322)	225 (175–273)	−61.53800	<0.001
DTP, median (IQR), min	144 (100–207)	109 (76–158)	−45.91377	0.060
PTR time, median (IQR), min	87 (53–123)	83 (50–123)	0.99663	0.857
Number of MT passes, median (IQR)	2 (1–3)	1 (1–2)	−0.36955	0.009
Total number of operation, median (IQR)	2 (1–3)	2 (1–3)	−0.36790	0.009
Safety outcomes
Symptomatic ICH within 24 h	18/179 (10.06)	16/282 (5.67)	0.538 (0.267–1.085)	0.083
Any ICH within 24 h	51/181 (28.18)	62/286 (21.68)	0.706 (0.459–1.083)	0.111
PH-2 within 24 h	12/181 (6.63)	8/286 (2.80)	0.405 (0.162–1.012)	0.053
Death within 90 d	37/143 (25.87)	54/237 (22.78)	0.845 (0.522–1.369)	0.494
Distal or new territorial embolization	13 (6.95)	12 (4.07)	0.568 (0.253–1.272)	0.169
Arterial perforation	5 (2.67)	8 (2.71)	1.015 (0.327–3.149)	0.980
Arterial dissection	2 (1.07)	0 (0)	–	0.957
Arterial vasospasm	4 (2.14)	1 (0.34)	0.156 (0.017–1.403)	0.097
Total complications	23 (12.30)	21 (7.12)	0.546 (0.293–1.018)	0.057

Abbreviations: OTP time, time from symptom onset to puncture; DTP time, time from door to puncture; PTR time, time from puncture to recanalization.

Table 3 Multivariate Analysis of Outcomes in Elderly Patients

	Model 1		Model 2
	Adjusted OR/β (95% CI)	P-value	Adjusted OR/β (95% CI)	P-value
Efficacy outcome
mRS at 90 d, median (IQR)	0.02080	0.925	−0.04827	0.822
mRS 0–1 at 90 d	0.945 (0.629–1.418)	0.784	0.976 (0.634–1.503)	0.914
mRS 0–2 at 90 d	1.003 (0.672–1.496)	0.990	1.050 (0.687–1.604)	0.822
mRS 0–3 at 90 d	1.185 (0.802–1.752)	0.394	1.278 (0.846–1.930)	0.244
Change in NIHSS score at 24 h, median (IQR)	−1.81529	0.029	−1.41694	0.075
Change in NIHSS score at 7 d, median (IQR)	−1.51778	0.165	−0.74295	0.436
Successful recanalization	1.158 (0.649–2.066)	0.620	1.158 (0.641–2.089)	0.627
OTP time, median (IQR), min	−59.94518	0.001	−55.07449	0.002
DTP time, median (IQR), min	−49.80116	0.053	−44.82975	0.085
PTR time, median (IQR), min	2.78556	0.634	2.97991	0.612
Pass number of thrombectomy, median (IQR)	−0.12366	0.354	−0.07015	0.599
Total number of operation, median (IQR)	−0.16219	0.243	−0.10225	0.466
Safety outcomes
Symptomatic ICH within 24 h	0.522 (0.244–1.116)	0.093	0.453 (0.198–1.036)	0.061
Any ICH within 24 h	0.816 (0.515–1.291)	0.385	0.839 (0.513–1.374)	0.486
PH-2 within 24 h	0.318 (0.114–0.890)	0.029	0.287 (0.096–0.856)	0.025
Death within 90 d	0.813 (0.484–1.365)	0.433	0.775 (0.450–1.335)	0.359
Distal or new territorial embolization	0.403 (0.164–0.990)	0.047	0.450 (0.178–1.141)	0.093
Total complications	0.463 (0.234–0.916)	0.027	0.499 (0.248–1.004)	0.052

Notes: Model 1 was adjusted for men, preoperative anticoagulants, aspiration catheter, intraoperative heparin, and the use of IVT. Model 2 was additional adjusted for baseline NIHSS, ASPECTS, location of the occluded vessels, and TOAST classification.

Table 4 The 90-Day mRS Between Bridging and Direct MT in Patients of Aged 65–79 and ≥80 Years Old

	65–79			≥80
	BMT (N=148)	DMT (N=246)	P-value	BMT (N=39)	DMT (N=49)	P-value
mRS 0–1	53 (35.81)	88 (35.77)	0.994	14 (35.90)	13 (26.53)	0.344
mRS 2–6	95 (64.19)	158 (64.23)		25 (64.10)	36 (73.47)
mRS 0–2	56 (37.84)	95 (38.62)	0.877	15 (38.46)	18 (36.73)	0.868
mRS 3–6	92 (62.16)	151 (61.38)		24 (61.54)	31 (63.27)
mRS 0–3	68 (45.95)	122 (49.59)	0.483	18 (46.15)	22 (44.90)	0.906
mRS 4–6	80 (54.05)	124 (50.41)		21 (53.85)	27 (55.10)

Figure 2 Distribution of the modified Rankin Scale (mRS) scores at 90 days.

Abbreviations: BMT, bridging mechanical thrombectomy; DMT, direct mechanical thrombectomy.