124 patients were identified aged 18–65 y. Nine patients were excluded for being treated with endovascular treatment, and 9 patients (7.8%) were lost to follow-up in our study. Among 106 patients remained, nine patients were diagnosed with bilateral MCAOs. A total of 115 MCAOs (represented as Cases below) were involved (Fig. 1).
The 115 cases (male: female = 76:39) enrolled were at a mean age of 47.5 ± 9.9 y (ranged 26–65 y). Sixty-four cases (male: female = 41:23) were involved in medical group, with a mean age of 50.31 ± 9.77 y. Fifty-one cases (male: female = 35:16) were involved in surgical group, with a mean age of 43.86 ± 8.96 y (Table 1). In the surgical group, 34 cases received direct revascularizations, and 17 cases received indirect revascularizations.
Table 1
Baseline Demographic of 115 Cases
Characteristic | Medical Group (n = 64)* | Surgical Group (n = 51)* | P value |
Age, mean(SD), y.o. | 50.31 (9.77) | 43.86 (8.96) | 0.001 |
Median (range), y.o. | 51.5 (26–65) | 45 (26–59) | |
Gender, male/female | 41/23 | 35/16 | 0.506 |
Initial symptom | | | |
Stroke | 35 (54.7) | 36 (70.6) | 0.060 |
TIA | 22 (34.4) | 13 (25.5) | 0.205 |
Incident | 7 (10.9) | 2 (3.9) | 0.149 |
Hypertension | 44 (68.8) | 33 (64.7) | 0.595 |
Hyperlipidemia | 30 (46.9) | 9 (17.6) | 0.001 |
Diabetes mellitus | 21 (32.8) | 14 (27.5) | 0.432 |
Coronary artery disease | 3 (4.7) | 0 | 0.119 |
Unrelated cerebral infarction | 15 (23.4) | 1 (2) | 0.001 |
Smoking history | | | |
Current | 16 (25) | 8 (15.7) | 0.161 |
Former | 15 (23.4) | 4 (7.8) | 0.021 |
Never | 33 (51.6) | 39 (76.5) | 0.005 |
Drinking history | | | |
Never | 39 (60.9) | 43 (84.3) | 0.005 |
Mild | 14 (21.9) | 3 (5.9) | 0.014 |
Medium | 8 (12.5) | 2 (3.9) | 0.097 |
Severe | 3 (4.7) | 3 (5.9) | 0.547 |
Blood pressure, mean(SD), mmHg | | | |
Systolic | 135.28 (16.08) | 128.55 (14.21) | 0.024 |
Diastolic | 83.41 (11.73) | 80.47 (8.93) | 0.377 |
BMI, mean (SD)† | 26.2 (4.3) | 25.4 (3.3) | 0.186 |
Median (range)† | 26.0 (19.1–41.8) | 24.9 (20.6–34.3) | |
Overweight (24-27.4 BMI)† | 22 (34.4) | 26 (51.0) | 0.048 |
Obese (≥ 27.5 BMI)† | 21 (32.8) | 7 (13.7) | 0.034 |
NIHSS score, mean (SD)‡ | 1.05 (2.00) | 1.80 (2.00) | 0.230 |
Range‡ | 0–13 | 0–8 | |
mRS score, mean(SD)§ | 0.69 (0.77) | 1.80 (1.06) | 0.000 |
mRS score ≥ 2§ | 5 (7.8) | 25 (49) | 0.000 |
Compensatory collateral arteryII | | | |
IntracranialII | 51 (79.7) | 33 (64.7) | 0.055 |
ExtracranialII | 7 (10.9) | 2 (3.9) | 0.073 |
Concomitant cerebral arterial stenosisII | 31 (48.4) | 28 (54.9) | 0.350 |
IpsilateralII | 14 (21.9) | 7 (13.7) | 0.595 |
Abnormal CTP result | 45 (70.3) | 49 (96.1) | 0.000 |
Related cerebral infarction¶ | 48 (75) | 37 (72.5) | 0.465 |
Prehospital routine medication | | | |
Aspirin | 48 (75) | 28 (54.9) | 0.020 |
Clopidogrel | 33 (51.6) | 3 (5.9) | 0.000 |
Antihypertension | 26 (40.6) | 19 (37.3) | 0.431 |
Lipid-lowering | 51 (79.7) | 18 (35.3) | 0.000 |
Antidiabetes | 10 (15.6) | 6 (11.8) | 0.376 |
Abbreviations: TIA, Transient ischemic attack; BMI, body mass index; NIHSS, National Institutes of Health Stroke Scale; mRS, modified Rankin’s Scale; CTP, computed tomography perfusion. * Data are reported as No.(%) unless otherwise indicated. † BMI was calculated as weight in kilograms divided by height in meters squared. The threshold values of overweight and obese refer to National Standards published by National Health Commission of the People’s Republic of China. ‡ NIHSS score is based on a 42-point scale (0 indicates normal, and 42 indicates coma or death). § mRS score is based on a 7-point scale (0 indicates normal, ≥ 2 is defined as neural function deficit, 6 indicates death). II Compensatory collateral artery is based on the images of digital subtraction angiography (DSA) or computed tomographic angiography (CTA). ¶ Related cerebral infarction is based on the results of computed tomography and magnetic resonance image. |
During a mean follow-up of 42.7 months (ranged 2–80 months), the incidence of SIE was 17.2% (n = 11) in medical group, and 19.6% (n = 10) in surgical group (Table 2). The incidences of fatal stroke were 1.6% (1 out of 64) and 3.9% (2 out of 51) in the medical and surgical group, respectively. SIE incidences were similar between groups (in total, OR = 1.175, 95% CI 0.455 ~ 3.034; in SIE subtypes, P = 0.365). In Kaplan-Meier estimates, there was no difference revealed between groups (Log Rank, P = 0.358 and Breslow, P = 0.230, Fig. 2a).
Table 2
Outcomes by Intergroup Analyses*
| | Medical Group (n = 64) | Surgical Group (n = 51) | P Value |
Primary outcome | | | | |
| SIEs(total) | 11 | 10 | 0.810 |
| Fatal stroke† | 1 | 2 | 0.584 |
Secondary outcomes | | | | |
| Types of SIEs‡ | 11 | 10 | 0.365 |
| Aggressive recurrence | 7 | 9 | 0.420 |
| New onset† | 4 | 1 | 0.392 |
| SIEs-free survival time§ (months) | 24.91 ± 22.86 | 43.50 ± 25.98 | 0.097 |
Abbreviation: SIEs, secondary ischemic events. * P values were computed using Spears Chi-square test unless otherwise indicated. † P values were computed using Fisher’s exact test ‡ Using 2⋅3 Chi-square tests § P value was computed using Independent-sample t test |
Further subgroup analyses were performed in surgical group, between direct revascularization (DR) subgroup (n = 34) and indirect revascularization (IR) subgroup (n = 17). The baseline information of subgroups was different in age (DR group vs IR group = 41.91 ± 9.44 y vs 47.76 ± 6.54 y, t-test, P = 0.026) and hyperlipidaemia history (DR vs IR = 26.5% vs 0%, Fisher’s exact test, P = 0.017). The incidences of SIE were 29.4% and 0% in DR subgroup and IR subgroup, respectively (OR = 0.706, 95% CI 0.568 ~ 0.877). Cases in IR subgroup had a higher cumulative SIE-free survival rate than those in DR subgroup (Log-rank P = 0.015, Breslow P = 0.043, Fig. 2b). Compared with medical group, IR subgroup resulted in a lower incidence of SIE (17.2% vs 0%, P = 0.061, 95% CI 0.741 ~ 0.926) and a higher SIE-free survival rate (Log-rank P = 0.044, Fig. 2c). Between medical group and DR subgroup, no significant difference was observed in either SIE incidence (17.2% vs 29.4%, P = 0.160, 95%CI 0.919 ~ 1.497) or SIE-free survival rate (Log-rank P = 0.097, Breslow P = 0.065, Fig. 2d).
ROC analyses revealed that cutoff ages were 48 y and 43 y in surgical group and medical group, respectively, which indicated a higher SIE incidence in the older cases. Among the cases aged 43 y -48 y, SIE incidences were indifferent between groups (surgical groups vs medical group = 1/14 vs 4/11, Fisher’s exact test, P = 0.096). However, surgical revascularizations induced a higher SIE-free accumulative survival rate (Log Rank P = 0.067, Breslow P = 0.033). Further intersubgroup comparisons were conducted. The cutoff age of DR subgroup was identified to be 48 y, too. SIE incidences were 1/6 and 4/11 in DR subgroup and medical group, respectively, without significant difference (DR subgroup vs medical group = 1/6 vs 4/11, Fisher’s exact test, P = 0.395, 95%CI). The SIE-free survival rates of DR subgroup and medical group were without significant difference, neither (Log Rank P = 0.379, Breslow P = 0.230).
Factors that affected patients’ SIE-free survival were obtained in Cox regressions. The age༞43 y (HR = 7.841, 95%CI 1.346–45.693), concomitant intracerebral arterial stenosis (HR = 5.358, 95%CI 1.523–18.858), and the history of hyperlipidaemia (HR = 5.194, 95%CI 1.394–19.358) were revealed to be risk factors of SIE-free survival. Meanwhile, taking antihypertensive drugs (HR = 0.137, 95%CI 0.038–0.489) and the existence of extracranial compensatory arteries (HR = 0.216, 95%CI 0.068–0.688) were revealed to contributors to survival.