Mechanical thrombectomy is increasingly being used for the treatment of acute ischemic stroke. The population over 80 years of age is growing, and many of these patients have acute infarction; however, these patients are often excluded from clinical trials, so the aim of this study was to compare the functional outcomes and complication rates in very elderly patients (age ≥80 years) and aged patients (60–79 years) treated with mechanical thrombectomy.
Between January 2010 and June 2015, we retrospectively reviewed 113 senior patients (over 60 years old) treated at our institution for acute ischemic stroke with mechanical thrombectomy. They were divided into a very elderly (≥80 years) and aged (60–79 years) group, with comparisons in recanalization rates, complications, death and disability on discharge be reported.
The mean age was 70.3 years in the aged group and 83.4 years in the very elderly group. Elderly patients had higher rates of mechanical thrombectomy failure than the younger group (40% vs. 14%; odds ratio [OR] 4.1; 95% confidence interval [CI] 1.4–11.9;
Patients older than 80 years of age undergoing mechanical thrombectomy for acute infarction were more difficult to recanalize due to inaccessible occlusion sites and had a higher rate of infarction progression, However, mortality and other complications were similar to those in younger patients.
Although mortality rates have decreased, cerebrovascular disease, including stroke, are still a major cause of death, especially in the elderly in Korea
Some studies have investigated treatment with conventional intravenous thrombolysis in the elderly
In this study, we compared the functional outcomes and complication rates in very elderly patients (age ≥80 years) versus aged patients (60–79 years) in a single center after treatment with mechanical thrombectomy.
This study was approved by the Institutional Review Board and we retrospectively reviewed 113 senior patients (over 60 years old) who were treated for acute ischemic stroke with mechanical thrombectomy at our institution between January 2010 and June 2015. The patients were divided into two subgroups: those between 60 and 79 years old and those 80 years of age or over. Variables were compared between these subgroups.
The institutional management criteria for acute ischemic stroke are: 1) imaging evaluation performed immediately after visiting the emergency room (ER) and identifying the presence of hemorrhage, cerebral artery occlusion sites, and perfusion defects with perfusion computed tomography (CT); 2) administration of 0.9 mg/kg (10% bolus and 90% continuous infusion during 1 hour) if eligible for intravenous tissue plasminogen activator (tPA); 3) infarction area verified with magnetic resonance (MR) diffusion weighted imaging and the decision to treat with thrombectomy made by the neurosurgeons and neuro-interventionists considering the perfusion diffusion mismatching; 4) under informed consent from patients or their families, endovascular thrombectomy was carried out regardless of age; and 5) after the procedure, all patients underwent non-contrast CT immediately followed by imaging studies such as non-contrast CT and CT or MR angiography.
Patient data were collected including demographic data (sex and age), infarction risk factors, vascular occlusion sites, the use of intravenous tPA, time from symptom onset to ER visit, procedure time, complications (hemorrhage, progression, brain edema, and mortality) and need for secondary operation. Initial severity was assessed by the National Institutes of Health Stroke Scale (NIHSS). Reperfusion was classified using the modified thrombolysis in cerebral infarction (TICI) scale. Functional outcomes at discharge were measured according to the modified Rankin Scale (mRS). Mechanical thrombectomy was defined as the intra-arterial procedure including stent-retriever systems, the Penumbra system (Penumbra Inc., Alameda, CA, USA), and microwire maceration, with or without the administration of a chemical thrombolytic agent (urokinase or tirofiban), complications were classificated as hemorrhage, infarction progression, and brain edema according to the new lesions in the post-procedural imaging study compared with the initial examination, as well as aggravated neurologic symptoms.
The causes of failure were classified into three categories: first, the procedure was considered unsuccessful if occlusion sites were accessible, but recanalization failed after several attempts. Second, if there was no avenue to the occlusion site, the lesion was classified as inaccessible. Finally, ‘guiding failure’ was referred to when the guiding system was unable to perform the procedure, despite approaching the lesion.
Statistical analysis was performed using SPSS version 18.0 (IBM Corp., Armonk, NY, USA), continuous variables are presented as means plus or minus standard deviations, and variables were compared between the two subgroups using the Wilcoxon rank sum test for continuous variables and the chi-square or Fisher exact test for categorical variables. Univariate logistic regression models were used for the calculation of the odds ratio and their 95% confidence intervals. A probability value <0.05 was considered statistically significant.
A total of 171 patients were treated with endovascular thrombectomy for acute ischemic stroke in our institution between January 1, 2010 and June 30, 2015. Among these patients, 113 were senior patients, over 60 years of age, who underwent mechanical thrombectomy. Within this group of patients, 20 (17.7%) were very elderly (age ≥80 years) and 93 (82.3%) were aged patients (60–79 years). The mean age of the very elderly group was 83.4±2.3 years (range, 80–87 years), and that of the aged group was 70.3±5.5 years (range, 60–79 years). Baseline characteristics for the two groups are presented in
Fifty-five patients (48.7%) were male. In older patients, most of whom were female, the percentage of male patients (20%) was significantly lower compared to younger patients (54.8%,
The data in
Treatment outcome was evaluated at discharge using the mRS. There was a trend toward worse outcomes in the older group, with poor outcomes (mRS score 5–6) in 65% of very elderly patients versus 37.6% in aged patients (
There were no significant differences in the rate of any complication, such as hemorrhage, edema, mortality, or re-operation in the posttreatment period. However, infarction progression was observed eight times more often in the very elderly group than the aged group (3/20 [15%] vs. 2/93 [2.2%];
In this study, several infarction risk factors and occlusion vascular sites were identified, using intravenous tPA, time from symptom onset to ER visit, and procedure time. These results showed a few relevant factors, including male sex and tPA, that differed according to the age-related group. Korean statistics showed that the male to female ratio was 0.68 (2197606 men to 3227031 women) in those over 65 years of age, however this ratio decreased to 0.41 (280744 men to 681374 women) in the elderly group, based on the 2010 population and housing census
Research from Loh et al.
When failures after mechanical thrombectomy, including factors such as occlusion site, thrombectomy method and cause of failure was analyzed (
Furthermore, when assessing thrombectomy results in the short term, poor outcomes (mRS 5–6) were identified in the very elderly, while good outcomes (mRS 0–2) were shown significantly more often in aged patients (
Many studies have focused on the hemorrhagic transformation of complications after recanalization, and showed that these did not differ significantly in patients over 80 years compared with a younger group
A limitation of this study is that patient data was collected and analyzed retrospectively in a single institution. In addition, the treatment methods and procedure indications for acute ischemic patients were somewhat heterogeneous, including different thrombectomy devices and various agents. In the early part of the study period, wire-based maceration was mainly used. However in the latter part of the study, the use of stent retrievers and balloon guiding catheters due to development of the devices appeared to improve the results of treatment. Finally, the evaluated outcome was discharge mRS, the follow-up period was variable, ranging from two days to several weeks, which could be too short to accurately assess the results.
There is little known from previous clinical trials regarding the established treatment for acute ischemic stroke in very elderly patients. Thus, it is necessary to consider the outcomes of various treatments in this group. Although mortality and other complications were similar to those of younger patients, patients over 80 years of age undergoing mechanical thrombectomy for acute infarction were more difficult to recanalize due to inaccessible occlusion sites and a higher rate of infarction progression. Therefore, the procedure recommended should be decided with prudence.
Discharge modified Rankin Scale (mRS) score in very elderly patients (age ≥80 years) and aged patient (60–79 years).
Baseline characteristics of senior patients undergoing mechanical thrombectomy for acute infarction
Total (n=113) | Aged patient (60–79 years) (n=93) | Very elderly patients (age ≥80 years) (n=20) | ||
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Age (years) | 72.6±7.2 | 70.3±5.5 | 83.4±2.3 | <0.001 |
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Male sex | 55 (48.7) | 51 (54.8) | 4 (20.0) | 0.005 |
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Hypertension | 73 (64.6) | 61 (65.6) | 12 (60.0) | 0.635 |
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Diabetes mellitus | 30 (26.5) | 28 (30.1) | 2 (10.0) | 0.065 |
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Dyslipidemia | 9 (8.0) | 8 (8.6) | 1 (5.0) | >0.999 |
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Arterial fibrillation | 59 (52.2) | 48 (51.6) | 1 (55.0) | 0.783 |
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Previous stroke | 10 (8.8) | 9 (9.7) | 1 (5.0) | 0.688 |
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CAD | 8 (7.1) | 6 (6.5) | 2 (10.0) | 0.630 |
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Malignancy | 5 (4.4) | 5 (5.4) | 0 (0.0) | 0.584 |
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Renal disease | 3 (2.7) | 2 (2.2) | 1 (5.0) | 0.446 |
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Occlusion site | 0.334 | |||
ICA | 66 (58.4) | 51 (54.8) | 15 (75.0) | |
MCA | 27 (23.9) | 25 (26.9) | 2 (10.0) | |
ACA | 2 (1.8) | 2 (2.2) | 0 (0.0) | |
BA | 18 (15.9) | 15 (16.1) | 3 (15.0) | |
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IV tPA | 47 (41.6) | 44 (47.3) | 3 (15.0) | 0.008 |
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Time from onset to visit ER (min) | 149.9±191.1 | 144.0±18.0 | 177.3±58.5 | 0.845 |
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Procedure time (min) | 123.4±62.6 | 123.8±6.5 | 121.7±14.0 | 0.979 |
Values are presented as mean±standard deviation or number (%). CAD: coronary artery disease, ICA: internal carotid artery, MCA: middle cerebral artery, ACA: anterior cerebral artery, BA: basilar artery, ER: emergency room, IV tPA: intravenous tissue plasminogen activator
Comparison of recanalization, clinical outcomes and complications between aged patients and very elderly patients
Total (n=113) | Aged patient (60–79 years) (n=93) | Very elderly patients (age ≥80 years) (n=20) | ||
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Admission NIHSS | 14.2±6.5 | 13.9±6.4 | 15.6±6.7 | 0.331 |
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Reperfusion (TICI) | 0.005 | |||
Fail (0) | 21 (18.6) | 13 (14.0) | 8 (40.0) | |
Partial (1–2A) | 14 (12.4) | 10 (10.8) | 4 (20.0) | |
Major (2B–3) | 78 (69.0) | 70 (75.2) | 8 (40.0) | |
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Outcome (mRS) | 0.023 | |||
Good (0–2) | 21 (18.6) | 21 (22.6) | 0 (0.0) | |
Fair (3–4) | 44 (38.9) | 37 (39.8) | 7 (35.0) | |
Poor (5–6) | 48 (42.5) | 35 (37.6) | 13 (65.0) | |
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Complication | ||||
Hemorrhage | 15 (13.3) | 14 (15.1) | 1 (5.0) | 0.465 |
Progression | 5 (4.4) | 2 (2.2) | 3 (15.0) | 0.038 |
Edema | 6 (5.3) | 6 (6.5) | 0 (0.0) | 0.589 |
Mortality | 20 (17.7) | 16 (17.2) | 4 (20.0) | 0.752 |
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Operation | 10 (8.8) | 10 (10.8) | 0 (0.0) | 0.205 |
Values are presented as mean±standard deviation or number (%). NIHSS: National institutes of health stroke scales, TICI: thrombolysis in cerebral ischemia, mRS: modified Rankin scale
Univariate logistic regressions of recanalization, clinical outcomes and complications
Patient | Unadjusted OR (95% CI) | ||
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Reperfusion (TICI) | |||
Fail vs. partial+major | |||
Age group (n=93) | 13 (14.0) | 1 | |
Very elderly group (n=20) | 10 (10.8) | 4.1 (1.41–11.96) | 0.010 |
Major vs. fail+partial | |||
Age group (n=93) | 70 (75.3) | 1 | |
Very elderly group (n=20) | 8 (40.0) | 0.22 (0.08–0.60) | 0.003 |
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Outcome (mRS) | |||
Fair vs. good+poor | |||
Age group (n=93) | 37 (39.8) | 1 | |
Very elderly group (n=20) | 7 (35.0) | 0.82 (0.30–2.23) | 0.691 |
Poor vs. good+fair | |||
Age group (n=93) | 35 (37.6) | 1 | |
Very elderly group (n=20) | 13 (65.0) | 3.08 (1.12–8.45) | 0.029 |
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Complication | |||
Hemorrhage vs. none | |||
Age group (n=93) | 14 (15.1) | 1 | |
Very elderly group (n=20) | 1 (5.0) | 0.30 (0.04–2.40) | 0.255 |
Progression vs. none | |||
Age group (n=93) | 2 (2.2) | 1 | |
Very elderly group (n=20) | 3 (15.0) | 8.03 (1.25–51.72) | 0.028 |
Mortality vs. none | |||
Age group (n=93) | 16 (17.2) | 1 | |
Very elderly group (n=20) | 4 (20.0) | 1.20 (0.36–4.08) | 0.767 |
Values are presented as number (%) unless otherwise indicated. OR: odds ratio, CI: confidence interval, TICI: thrombolysis in cerebral ischemia, mRS: modified Rankin Scale
Analysis of the elderly patients who failed to mechanical thrombectomy
Total (n=21) | Aged patient (60–79 years) (n=13) | Very elderly patients (age ≥80 years) (n=8) | ||
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Age (years) | 74.7±8.2 | 69.7±6.1 | 82.8±2.7 | <0.001 |
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Male sex | 9 (42.9) | 8 (61.5) | 1 (12.5) | 0.067 |
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Location | 0.368 | |||
ICA | 7 (33.3) | 6 (46.2) | 1 (12.5) | |
MCA | 9 (42.9) | 4 (30.8) | 5 (62.5) | |
BA | 4 (19.0) | 2 (15.4) | 2 (25.0) | |
ACA | 1 (4.8) | 1 (7.7) | 0 (0.0) | |
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Treatment method | 0.0867 | |||
Stent-retriever systems | 9 (42.9) | 6 (46.2) | 3 (37.5) | |
Microwire maceration | 7 (33.3) | 6 (46.2) | 1 (12.5) | |
None | 5 (23.8) | 1 (7.7) | 4 (50.0) | |
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Fail cause | 0.0117 | |||
Unsuccessful procedure | 16 (76.2) | 12 (92.3) | 4 (50.0) | |
Inaccessible lesion | 4 (19.0) | 0 (0.0) | 4 (50.0) | |
Guiding failure | 1 (4.8) | 1 (7.7) | 0 (0.0) |
Values are presented as mean±standard deviation or number (%). ICA: internal carotid artery, MCA: middle cerebral artery, ACA: anterior cerebral artery, BA: basilar artery