Abstract
Objectives
Endovascular thrombectomy (EVT) has become the standard treatment for large vessel occlusion (LVO) in acute ischemic stroke. Stroke trials typically report clinical outcome at the three-month time point but there is a lack of studies focusing on the long-term outcome after EVT.
The aim of this study is to assess the long-term mortality after EVT for stroke and to determine the factors that are associated with mortality.
Methods
Retrospective single-center analysis of 323 patients who underwent EVT for stroke between the years 2015-2019 and survived at least 30 days. Patients were followed up until the end of the year 2020. Cox regression analysis was used to identify the factors associated with mortality.
Results
A total of 53 (16.4%) of the 30-day survivors died during the follow-up. According to the Cox regression analysis, mortality was associated with functional dependence (modified Rankin Scale (mRS) >2, HR 2.7 (95% CI 1.2-5.9), p=0.013), comorbidity (Charlson Comorbidity Index (CCI) ≥3, HR 2.7 (95% CI 1.4-5.5), p=0.004), stroke severity at baseline (National Institutes of Health Stroke Scale (NIHSS) >8, HR 1.9 (95% CI 1.1-3.3), p=0.026), and medical complications (HR 2.4 (95% CI 1.2-4.8), p=0.011). Procedural variables did not have an impact on mortality.
Conclusions
Functional dependence, stroke severity, comorbidity, and medical complications during the hospital stay were associated with the long-term mortality after EVT for stroke.
Introduction
Hyperacute treatments for acute ischemic stroke (AIS) have evolved in the recent years as endovascular thrombectomy (EVT) has become well established standard treatment in large vessel occlusion (LVO)
1
, 2
, 3
, 4
, 5
, 6
, 7
and the treatment of distal medium vessel occlusions with EVT is emerging.- Nogueira R.G.
- Jadhav A.P.
- Haussen D.C.
- et al.
Thrombectomy 6 to 24 hours after stroke with a mismatch between deficit and infarct.
N Engl J Med. 2018; 378https://doi.org/10.1056/nejmoa1706442
8
Despite the advances in the acute stroke treatments, stroke is still the second leading cause of death globally.9
- Abbafati C.
- Abbas K.M.
- Abbasi-Kangevari M.
- et al.
Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019.
Lancet N Am Ed. 2020; 396https://doi.org/10.1016/S0140-6736(20)30925-9
Life expectancy is increasing worldwide and the incidence of stroke is greatly influenced by age.
10
Hence, the total number of strokes is evidently expected to increase in coming years. The benefit of EVT is confirmed also in patients older than 80 years- Béjot Y.
- Bailly H.
- Durier J.
- Giroud M.
Epidemiology of stroke in Europe and trends for the 21st century.
Presse Med. 2016; 45https://doi.org/10.1016/j.lpm.2016.10.003
11
thus it is not appropriate to exclude elderly patients from the intervention solely based on age. For cost-effective utilization of healthcare resources, the recognition of patients who will benefit from acute stroke interventions becomes essential. There is a need to identify factors which are associated with poor outcome and mortality after EVT to improve patient selection and to prevent futile treatment.- Goyal M.
- Menon B.K.
- van Zwam W.H.
- et al.
Endovascular thrombectomy after large-vessel ischaemic stroke: a meta-analysis of individual patient data from five randomised trials.
Lancet N Am Ed. 2016; 387https://doi.org/10.1016/S0140-6736(16)00163-X
Outcomes after EVT are typically reported at standard 90-day time point. However, stroke patients often have comorbidities
12
and suffer from disability.- Noor A.
- Bennett G.
- Arndt S.
- Vidal G.
Comorbidities related to clinical outcomes in patients with acute ischemic stroke undergoing mechanical thrombectomy: review of literature and experience at a single comprehensive stroke center.
Ochsner J. 2019; 19https://doi.org/10.31486/toj.18.0108
13
Patients undergoing EVT are also prone to medical complications which are strongly associated with comorbidity and mortality in short-term follow-up.- Wafa H.A.
- Wolfe C.D.A.
- Emmett E.
- Roth G.A.
- Johnson C.O.
- Wang Y.
Burden of Stroke in Europe: thirty-year projections of incidence, prevalence, deaths, and disability-adjusted life years.
Stroke. 2020; 51https://doi.org/10.1161/STROKEAHA.120.029606
14
The data regarding long-term survival after EVT is limited, although a few studies suggest that the benefits on functional outcome are sustained and similar to 90-day outcome.- Junttola U.
- Lahtinen S.
- Liisanantti J.
- Vakkala M.
- Kaakinen T.
- Isokangas J.M.
Medical complications and outcome after endovascular therapy for acute ischemic stroke.
Acta Neurol Scand. 2021; 144https://doi.org/10.1111/ane.13501
15
, - McCarthy D.J.
- Diaz A.
- Sheinberg D.L.
- et al.
Long-term outcomes of mechanical thrombectomy for stroke: a meta-analysis.
Sci World J. 2019; 2019https://doi.org/10.1155/2019/7403104
16
, - Dávalos A.
- Cobo E.
- Molina C.A.
- et al.
Safety and efficacy of thrombectomy in acute ischaemic stroke (REVASCAT): 1-year follow-up of a randomised open-label trial.
Lancet Neurol. 2017; 16https://doi.org/10.1016/S1474-4422(17)30047-9
17
We aimed to investigate the long-term mortality after EVT for stroke and to determine the factors which are associated with mortality.- van den Berg L.A.
- Dijkgraaf M.G.W.
- Berkhemer O.A.
- et al.
Two-year outcome after endovascular treatment for acute ischemic stroke.
N Engl J Med. 2017; 376https://doi.org/10.1056/nejmoa1612136
Material and methods
This retrospective study was conducted at Oulu University Hospital, Finland, the Comprehensive Stroke Center for the four Primary Stroke Centers in Northern Finland. The study protocol was approved by the hospital administration (reference number 268/2019) and due to the retrospective study design no statement from the local ethics committee was needed.
Patients and inclusion criteria
During the time period between January 2015 and December 2019, 380 consecutive patients received EVT for acute stroke at Oulu University Hospital. In our hospital patients are eligible for EVT when they present with acute ischemic stroke due to an occlusion in the intracranial internal carotid artery, the first or second segment of the middle cerebral artery or in the basilar artery established on computed tomographic angiography (CTA) and a score of 6 or higher on the National Institutes of Health Stroke Scale (NIHSS) and no large ischemic lesion on baseline non-contrast head computed tomography (CT). In extended time-window patient selection is based on perfusion imaging. These patients were retrospectively identified and screened from the Thrombectomy Registry of Oulu University Hospital. A total of 323 patients who survived at least 30 days after intervention were included into the present study.
We collected patients` baseline demographics and characteristics including age, sex, National Institutes of Health Stroke Scale (NIHSS) score on admission, pre-stroke modified Rankin scale (mRS) score, and Charlson Comorbidity Index (CCI). CCI is a method which categorizes patient`s comorbidities based on the diagnoses in medical records.
18
Procedural data included treatment with intravenous thrombolysis and the type of stroke onset. We used the determination of occlusion site as either anterior or posterior circulation. The grade of recanalization was defined as modified Thrombolysis in Cerebral Infarction Scale (mTICI).- Deyo R.A.
- Cherkin D.C.
- Ciol M.A.
Adapting a clinical comorbidity index for use with ICD-9-CM administrative databases.
J Clin Epidemiol. 1992; 45https://doi.org/10.1016/0895-4356(92)90133-8
19
Post-procedural variables included NIHSS score on the first post-procedural day, infarction size in 24 h control head computed tomography (CT), and medical complications during the hospital stay. Laboratory results during the first three days of the hospital stay were collected and the hospital LOS was determined. The data was collected on structured forms and digitalized.- Tung E.L.
- McTaggart R.A.
- Baird G.L.
- et al.
Rethinking thrombolysis in cerebral Infarction 2b: which thrombolysis in cerebral infarction scales best define near complete recanalization in the modern thrombectomy era?.
Stroke. 2017; 48https://doi.org/10.1161/STROKEAHA.117.017182
Complications were classified as reported in our previous study which focused on medical complications in this patient group
14
including medical complications (pneumonia, acute myocardial infarction, acute kidney injury, cardiac insufficiency, pulmonary embolism, deep venous thrombosis, delirium, gastrointestinal bleeding and atrial fibrillation) and neurological complications (any hemorrhagic findings in control head CT and acute seizures).- Junttola U.
- Lahtinen S.
- Liisanantti J.
- Vakkala M.
- Kaakinen T.
- Isokangas J.M.
Medical complications and outcome after endovascular therapy for acute ischemic stroke.
Acta Neurol Scand. 2021; 144https://doi.org/10.1111/ane.13501
Statistics Finland provided the data concerning the dates of death. Patients were followed until the end of the year 2020.
Statistical analysis
The data was analyzed using IBM SPSS Statistics for Windows (Version 27 IBM Corp). Categorical variables, presented as numbers and percentages, were compared using Pearson`s Chi square test. Continuous variables, presented as medians and 25th and 75th percentiles [25th–75th PCT], were analyzed using the non-parametric Mann-Whitney test. P-value less than 0.05 was considered statistically significant. Variables with univariate significance less than 0.1 were entered into a multivariate proportional hazards Cox model to assess hazard ratios (HR) and 95% confidence intervals (95% CI) for mortality. Variables with multivariate significance less than 0.05, and those with significant impact on the log likelihood function were kept in the model. According to the Cox regression model, Kaplan-Meier survival curves were drawn for the clinically most significant variables.
Results
During the study period 379 patients underwent EVT. One patient experienced two separate interventions due to a recurrent stroke during two hospital admissions. During the hospital stay 18 (4.8%) patients died. At 30 days, there were 323 (85.2%) patients alive. The median age of these 30-day survivors was 70 [60-79] years and 177 (54.8%) of them were male. (Table 1).
Table 1Baseline characteristics of 30-day survivors after endovascular thrombectomy for stroke.
| Alive | Deceased | Missing | P-Value | |
|---|---|---|---|---|
| N=270 | N=53 | |||
| Gender, male | 154 (57.0) | 23 (43.4) | 0 | 0.068 |
| Age, yr | 69 [58-77] | 78 [69-84] | 0 | <0.001 |
| Weight, kg | 80 [67-86] | 75 [67-84] | 32 | 0.220 |
| Smoking | 54(20.0) | 3 (5.7) | 0 | 0.012 |
| CCI-score >3 | 129 (48.0) | 41 (77.4) | 1 | <0.001 |
| mRS baseline | 0 [0-1] | 1 [0-2] | 3 | <0.001 |
| NIHSS baseline | 13 [7-16] | 15 [11-18] | 0 | 0.008 |
| Laboratory Results | ||||
| Hemoglobin g/L | 136 [126-148] | 130 [118-142] | 4 | 0.019 |
| Thrombocytes | 2 | 0.514 | ||
| E9/L | 216 [178-252] | 225 [170-270] | ||
| Creatinine | 4 | 0.202 | ||
| μmol/L | 72 [59-85] | 77 [59-90] | ||
| CRP mg/L | 0 [0-7] | 9 [0-20] | 0 | <0.001 |
Categorical variables are presented as absolute numbers (N) and percentages (%). Continuous variables are presented as medians with 25th and 75th percentiles [25-75th PCT].
† Charlson Comorbidity Index
‡ modified Rankin Scale of functional dependence ranges from 0 (no symptoms) to 6 (death)
§ National Institutes of Health Stroke Scale range from 0 to 42, with higher scores indicating a greater clinical deficit
¶ C-reactive protein
The median follow-up time was 2.9 [1.9-4.1] years and 53 (16.4%) of the 30-day survivors died during the follow-up. The mortality of the 30-day survivors was 3.1% at 90 days and 9.0% at one year. Patient baseline characteristics are shown in Table 1. The non-survivors were older (78 [69-84] vs 69 [58-77] years, p<0.001), had higher CCI-score (6 [4-7] vs 3 [2-5], p<0.001), lower pre-stroke functional status (1 [0-2] vs [0-1] mRS, p<0.001), and higher CRP (9 [0-20] vs 0 [0-7], p<0.001) compared with the survivors.
There were no differences in procedural variables between the non-survivors and the survivors. The rate of complete recanalization was comparable in both groups (54.3% vs 61.3%, p=0.376) as was also the rate of posterior circulation stroke (15.1% vs 18.7%). (Table 2).
Table 2Procedural data of 30-day survivors after endovascular thrombectomy for stroke.
| Alive | Deceased | Missing | P-value | |
|---|---|---|---|---|
| N=270 | N=53 | |||
| Treatment with intravenous thrombolysis | ||||
| IVT +EVT | 138 (51.5) | 25 (47.2) | 2 | 0.565 |
| EVT alone | 130 (48.5) | 28 (52.8) | ||
| Type of stroke onset | ||||
| Witnessed | 209 (78.6) | 44 (83.0) | 4 | 0.694 |
| Unwitnessed | 57 (21.4) | 9 (17.0) | ||
| Occlusion site | ||||
| Anterior circulation | 217 (81.3) | 45 (84.9) | 3 | 0.531 |
| Posterior circulation | 50 (18.7) | 8 (15.1) | ||
| Recanalization result | ||||
| TICI 3 | 149 (61.3) | 25 (54.3) | ||
| TICI 2B-2C | 83 (34.2) | 17 (36.9) | 34 | 0.429 |
| TICI 0-2A | 11 (4.5) | 4 (8.6) | ||
| Process measures | ||||
| Median time from stroke onset to groin puncture (min) | 309 [210-516] | 314 [235-488] | 0 | 0.556 |
| Median time from hospital admission to groin puncture (min) | 74 [44-114] | 81 [55-128] | 0 | 0.165 |
| Median time from groin puncture to recanalization (min) | 45 [29-70] | 50 [28-84] | 0 | 0.369 |
| Contrast media amount (ml) | 170 [140-205] | 170 [135-200] | 0 | 0.881 |
Categorical variables are presented as absolute numbers (N) and percentages (%). Continuous variables are presented as medians with 25th and 75th percentiles [25–75th PCT].
† Intravenous thrombolysis
‡ Endovascular thrombectomy
§ The modified Thrombolysis in Cerebral Infarction scale, ranges from 0 to 3, with a grade of 2b, 2c and 3 indicating successful reperfusion
The non-survivors had higher NIHSS-score (12 [4-16] vs 6 [4-13] p=0.009) on the first post-procedural day. They also had lower albumin levels (30 [26-33] vs 32 [29-34], p=0.008) and suffered more often medical complications (77.4% vs 53.7%), p=0.001) compared with the survivors. Hemorrhagic transformation in control neuroimaging was more common among the non-survivors, but the difference was not statistically significant (26.4% vs 18.7%, p= 0.196). The size of the infarction was larger in the non-survivors (p=0.036) (Table 3). The rate of the symptomatic intracranial hemorrhage among the 30-day survivors was 5.4%.
Table 3Post-procedural outcome of 30-day survivors after endovascular thrombectomy for stroke.
| Alive | Deceased | Missing | P-Value | |
|---|---|---|---|---|
| N=270 | N=53 | |||
| Clinical | ||||
| Median NIHSS | ||||
| score on 1st post- | ||||
| procedural day | 6 [4-13] | 12 [4-16] | 0 | 0.009 |
| Control Imaging | ||||
| Infarction size | ||||
| No infarction | 35 (13.0) | 11 (20.7) | ||
| Small-medium infarction | 142 (53.0) | 18 (34.0) | ||
| Large infarction | 91 (34.0) | 24 (45.3) | 2 | 0.036 |
| Hemorrhage | ||||
| No hemorrhage | 218 (81.3) | 39 (73.6) | ||
| Any hemorrhage | 50 (18.7) | 14 (26.4) | 0.196 | |
| Medical complications | ||||
| No | 125 (46.3) | 12 (22.6) | ||
| Yes | 145 (53.7) | 41 (77.4) | 0 | 0.001 |
| Neurological complications | ||||
| No | 224 (83.0) | 39 (73.6) | ||
| Yes | 46 (17.0) | 14 (26.4) | 0 | 0.108 |
| Laboratory results | ||||
| Creatinine μmol/L | 65 [55-78] | 72 [58-85] | 47 | 0.059 |
| Albumin g/L | 32 [29-34] | 30 [26-33] | 113 | 0.008 |
| Hosp LOS (d) | 6 [4-8] | 6 [4-8] | 0 | 0.916 |
Categorical variables are presented as numbers (N) and percentages (%). Continuous variables are presented as medians with 25th and 75th percentiles [25–75th PCT].
† National Institutes of Health Stroke Scale range from 0 to 42, with higher scores indicating a greater clinical deficit
‡ Hospital length of stay
According to the Cox regression analysis pre-stroke functional dependence (mRS >2, HR 2.7 (95% CI 1.2-5.9), p=0.013), medical complications (HR 2.4 (95% CI 1.2-4.8), p=0.011), stroke severity at baseline (NIHSS >8, HR 1.9 (95% CI 1.1-3.3), p=0.026), and comorbidity (CCI≥3, HR 2.7 (95% CI 1.4-5.5), p=0.004) were associated with death during the follow-up (Table 4).
Table 4HR and 95% confidence intervals for death among 30-day survivors after endovascular thrombectomy for stroke.
| HR (95% CI) | P-value | |
|---|---|---|
| mRS >2 | 2.7 (1.2-5.9) | 0.013 |
| At least moderate dependence | ||
| At least one medical complication | 2.4 (1.2-4.8) | 0.011 |
| NIHSS baseline >8 | 1.9 (1.1-3.3) | 0.026 |
| CCI ≥3 | 2.7 (1.4-5.5) | 0.004 |
† modified Rankin Scale of functional dependence ranges from 0 (no symptoms) to 6 (death)
‡ National Institutes of Health Stroke Scale range from 0 to 42, with higher scores indicating a greater clinical deficit
§ Charlson Comorbidity Index
The cumulative survival of the patients with medical complications compared with the patients with no medical complications is presented in Fig. 1. The cumulative survival in comparison between the patients with high and low comorbidity burden is presented in Fig. 2.
Fig. 1Kaplan-Meier curve for long-term cumulative survival in the 30-day survivors with and without medical complications in 3-year follow-up.
Fig. 2Kaplan-Meier curve for long-term cumulative survival in the 30-day survivors with either high or low comorbidity burden in 3-year follow-up.
Discussion
Our study shows that after surviving the acute phase, a total of 16% of patients who underwent EVT for stroke died during the long-term follow-up. Pre-stroke functional dependence, comorbidity, stroke severity, and medical complications during the hospital stay were independently associated with mortality. There was no difference in recanalization result, hemorrhagic transformation, or posterior circulation stroke between the survivors and the non-survivors.
In the present study, the mortality among 30-day survivors was lower compared with previous anterior circulation EVT studies; REVASCAT and MR CLEAN reported 23% mortality at one year and 26.0% cumulative mortality in two-year follow-up, respectively.
16
,- Dávalos A.
- Cobo E.
- Molina C.A.
- et al.
Safety and efficacy of thrombectomy in acute ischaemic stroke (REVASCAT): 1-year follow-up of a randomised open-label trial.
Lancet Neurol. 2017; 16https://doi.org/10.1016/S1474-4422(17)30047-9
17
Accordingly, Chinese study reported a mortality rate of 28% in a median follow-up period of 20 months.- van den Berg L.A.
- Dijkgraaf M.G.W.
- Berkhemer O.A.
- et al.
Two-year outcome after endovascular treatment for acute ischemic stroke.
N Engl J Med. 2017; 376https://doi.org/10.1056/nejmoa1612136
20
Comparably Wu et al reported a rate of 38% for one-year mortality in basilar artery occlusion patients treated with EVT.- Zhao W.
- Shang S.
- Li C.
- et al.
Long-term outcomes of acute ischemic stroke patients treated with endovascular thrombectomy: a real-world experience.
J Neurol Sci. 2018; 390https://doi.org/10.1016/j.jns.2018.03.004
21
Our study population represents real-world clinical environment since we are the only operating Comprehensive Stroke Center in Northern Finland. We included all consecutive EVT-patients in this study and our study population contains both anterior and posterior circulation occlusions. Interestingly, our data suggests that posterior circulation occlusion does not have an impact on long-term mortality, even though short-term mortality in posterior circulation stroke is rather high.- Wu L.
- Zhang D.
- Chen J.
- et al.
Long-term outcome of endovascular therapy for acute basilar artery occlusion.
J Cereb Blood Flow Metab. 2021; 41https://doi.org/10.1177/0271678X20958587
22
- Gattringer T.
- Posekany A.
- Niederkorn K.
- et al.
Predicting early mortality of acute ischemic stroke: score-based approach.
Stroke. 2019; 50https://doi.org/10.1161/STROKEAHA.118.022863
Although data regarding prognostic factors for long-term survival after EVT are limited, other studies have previously identified that stroke severity,
20
,- Zhao W.
- Shang S.
- Li C.
- et al.
Long-term outcomes of acute ischemic stroke patients treated with endovascular thrombectomy: a real-world experience.
J Neurol Sci. 2018; 390https://doi.org/10.1016/j.jns.2018.03.004
23
, - Hallevi H.
- Barreto A.D.
- Liebeskind D.S.
- et al.
Identifying patients at high risk for poor outcome after intra-arterial therapy for acute ischemic stroke.
Stroke. 2009; 40https://doi.org/10.1161/STROKEAHA.108.535146
24
, - Sarraj A.
- Albright K.
- Barreto A.D.
- et al.
Optimizing prediction scores for poor outcome after intra-arterial therapy in anterior circulation acute ischemic stroke.
Stroke. 2013; 44https://doi.org/10.1161/STROKEAHA.113.001050
25
comorbidity,- Saposnik G.
- Guzik A.K.
- Reeves M.
- Ovbiagele B.
- Johnston S.C.
Stroke prognostication using age and NIH stroke scale: SPAN-100.
Neurology. 2013; 80https://doi.org/10.1212/WNL.0b013e31827b1ace
26
and pre-stroke functional dependence- Flint A.C.
- Cullen S.P.
- Faigeles B.S.
- Rao V.A.
Predicting long-term outcome after endovascular stroke treatment: the totaled health risks in vascular events score.
Am J Neuroradiol. 2010; 31https://doi.org/10.3174/ajnr.A2050
27
,- Seker F.
- Pfaff J.
- Schönenberger S.
- et al.
Clinical outcome after thrombectomy in patients with stroke with premorbid modified rankin scale scores of 3 and 4: a cohort study with 136 patients.
Am J Neuroradiol. 2019; 40https://doi.org/10.3174/ajnr.A5920
28
are associated with poor outcome. Our study presents a novel finding of these variables being independently associated with the long-term mortality in EVT-patients. According to the present results, after the primary survival from the stroke, the patient-related factors instead of the stroke-related factors play a major role in the survival. According to our knowledge, medical complications have not previously been reported to be related to the long-term mortality in this patient group. We have recently shown that the medical complications are common after EVT and have a negative impact on the short-term functional outcome.- Deb-Chatterji M.
- Pinnschmidt H.
- Flottmann F.
- et al.
Stroke patients treated by thrombectomy in real life differ from cohorts of the clinical trials: a prospective observational study.
BMC Neurol. 2020; 20https://doi.org/10.1186/s12883-020-01653-z
14
Patients with comorbidities are prone to medical complications.- Junttola U.
- Lahtinen S.
- Liisanantti J.
- Vakkala M.
- Kaakinen T.
- Isokangas J.M.
Medical complications and outcome after endovascular therapy for acute ischemic stroke.
Acta Neurol Scand. 2021; 144https://doi.org/10.1111/ane.13501
29
According to these findings, medical complications are not directly related to unfavorable outcomes; they are rather a surrogate of poor health leading to death during the recovery phase of acute disease. Among surgical patients, postoperative complications which occurred during the first 30 postoperative days are more significantly related to survival than operative risk or perioperative risk factors.- Kim B.R.
- Lee J.
- Sohn M.K.
- et al.
Risk factors and functional impact of medical complications in stroke.
Ann Rehabil Med. 2017; 41https://doi.org/10.5535/arm.2017.41.5.753
30
Our finding that medical complications are associated with long-term mortality suggests the same and indicates that medical complications have a sustained negative impact on the survival after invasive treatments.- Lahtinen S.
- Koivunen P.
- Ala-Kokko T.
- et al.
Short- and long-term mortality and causes of death after reconstruction of cancers of the head and neck with free flaps.
Br J Oral Maxillofac Surg. 2019; 57https://doi.org/10.1016/j.bjoms.2018.12.004
Functionally dependent patients have been excluded from randomized trials of acute stroke treatments
1
, 2
, 3
, 4
, 5
and there is uncertainty if they could benefit from the intervention. Despite conflicting results concerning possible benefits of acute treatments in this patient group,31
,- Gumbinger C.
- Ringleb P.
- Ippen F.
- et al.
Outcomes of patients with stroke treated with thrombolysis according to prestroke Rankin Scale scores.
Neurology. 2019; 93https://doi.org/10.1212/WNL.0000000000008468
32
our study shows that pre-stroke dependency has an independent association with mortality. Similarly, Swedish group reported a clear association between pre-stroke functional dependency and high mortality rate in a long-term follow-up after acute ischemic stroke.- Goldhoorn R.J.B.
- Verhagen M.
- Dippel D.W.J.
- et al.
Safety and outcome of endovascular treatment in prestroke-dependent patients: results from MR CLEAN registry.
Stroke. 2018; 49https://doi.org/10.1161/STROKEAHA.118.022352
33
The current knowledge suggests withholding EVT or at least making treatment decisions upon individual basis in this patient group. However, in the every-day clinical practice time-sensitive assessments of patient´s functional capacity may be complex and not always precise.- Sennfält S.
- Pihlsgård M.
- Norrving B.
- Ullberg T.
- Petersson J.
Ischemic stroke patients with prestroke dependency: characteristics and long-term prognosis.
Acta Neurol Scand. 2021; 143https://doi.org/10.1111/ane.13328
According to previous studies, successful recanalization has been associated with favorable outcome
28
,- Deb-Chatterji M.
- Pinnschmidt H.
- Flottmann F.
- et al.
Stroke patients treated by thrombectomy in real life differ from cohorts of the clinical trials: a prospective observational study.
BMC Neurol. 2020; 20https://doi.org/10.1186/s12883-020-01653-z
34
and decreased likelihood of death.- Fields J.D.
- Lutsep H.L.
- Smith W.S.
Higher degrees of recanalization after mechanical thrombectomy for acute stroke are associated with improved outcome and decreased mortality: pooled analysis of the MERCI and multi MERCI trials.
Am J Neuroradiol. 2011; 32https://doi.org/10.3174/ajnr.A2709
34
,- Fields J.D.
- Lutsep H.L.
- Smith W.S.
Higher degrees of recanalization after mechanical thrombectomy for acute stroke are associated with improved outcome and decreased mortality: pooled analysis of the MERCI and multi MERCI trials.
Am J Neuroradiol. 2011; 32https://doi.org/10.3174/ajnr.A2709
35
In contrast to previous results, we did not find an association between recanalization result and mortality. This difference may be explained by the fact that previous studies have focused on the short-term outcome and survival. It may be hypothesized that there are different factors impacting the short- and long-term mortalities. Moreover, we serve as Comprehensive Stroke Center and approximately 40% of our patients are transferred from other hospitals. Transfer delay contributes to expansion of neuronal injury and reduces the impact of successful recanalization.- Awad A.W.
- Kilburg C.
- Ravindra V.M.
- et al.
Predicting death after thrombectomy in the treatment of acute stroke.
Front Surg. 2020; 7https://doi.org/10.3389/fsurg.2020.00016
Clinical significance
The benefits of EVT are confirmed in wide range of patients
11
and in extended time-window.- Goyal M.
- Menon B.K.
- van Zwam W.H.
- et al.
Endovascular thrombectomy after large-vessel ischaemic stroke: a meta-analysis of individual patient data from five randomised trials.
Lancet N Am Ed. 2016; 387https://doi.org/10.1016/S0140-6736(16)00163-X
6
,7
Increasing amount of acute stroke patients are being evaluated to meet eligibility for acute stroke treatments, including thrombectomy. Despite promising results there are still patients who remain severely disabled or die after acute interventions.- Nogueira R.G.
- Jadhav A.P.
- Haussen D.C.
- et al.
Thrombectomy 6 to 24 hours after stroke with a mismatch between deficit and infarct.
N Engl J Med. 2018; 378https://doi.org/10.1056/nejmoa1706442
36
,- Ramos L.A.
- Kappelhof M.
- van Os H.J.A.
- et al.
Predicting poor outcome before endovascular treatment in patients with acute ischemic stroke.
Front Neurol. 2020; 11https://doi.org/10.3389/fneur.2020.580957
37
Appropriate patient selection is essential for optimal and cost-effective utilization of limited health care resources. Identifying factors which are associated with mortality provide tools for stroke clinicians for the every-day decision making.- Karamchandani R.R.
- Rhoten J.B.
- Strong D.
- Chang B.
- Asimos A.W.
Mortality after large artery occlusion acute ischemic stroke.
Sci Rep. 2021; 11https://doi.org/10.1038/s41598-021-89638-x
Comorbidity and functional dependence have a close relationship.
38
According to our results, these factors should be assessed when acute stroke patients are being evaluated to meet eligibility for EVT to prevent futile recanalization. Furthermore, every attempt should be made to prevent medical complications in this patient group.- Wolff J.L.
- Boult C.
- Boyd C.
- Anderson G.
Newly reported chronic conditions and onset of functional dependency.
J Am Geriatr Soc. 2005; 53https://doi.org/10.1111/j.1532-5415.2005.53262.x
We defined stroke severity as high baseline NIHSS similarly to many previous studies.
20
,- Zhao W.
- Shang S.
- Li C.
- et al.
Long-term outcomes of acute ischemic stroke patients treated with endovascular thrombectomy: a real-world experience.
J Neurol Sci. 2018; 390https://doi.org/10.1016/j.jns.2018.03.004
21
,- Wu L.
- Zhang D.
- Chen J.
- et al.
Long-term outcome of endovascular therapy for acute basilar artery occlusion.
J Cereb Blood Flow Metab. 2021; 41https://doi.org/10.1177/0271678X20958587
35
,- Awad A.W.
- Kilburg C.
- Ravindra V.M.
- et al.
Predicting death after thrombectomy in the treatment of acute stroke.
Front Surg. 2020; 7https://doi.org/10.3389/fsurg.2020.00016
37
Although we found baseline NIHSS to have an independent association with long-term mortality, it alone possesses an incomplete ability to predict outcome. Beyond admission, there are several additive factors having an impact on outcome. Baseline NIHSS is a good clinical tool but should not be used alone in the decision making when selecting patients for the intervention.- Karamchandani R.R.
- Rhoten J.B.
- Strong D.
- Chang B.
- Asimos A.W.
Mortality after large artery occlusion acute ischemic stroke.
Sci Rep. 2021; 11https://doi.org/10.1038/s41598-021-89638-x
Limitations
The present study has some limitations. First, low number of patients can be considered as a limitation but increasing the number of patients would have expanded the time period remarkably. On the other hand, we are the only operating Comprehensive Stroke Center in Northern Finland and therefore this is a population-based study. Although we used CCI to measure comorbidities precisely, we did not estimate the prognostic effects of individual comorbid conditions. Different comorbid conditions have unequal effects on mortality and survival, which should be kept in mind when making treatment decisions on the basis of comorbidity. Additionally, we were not able to provide ASPECTS on imaging at baseline because it is not commonly used score in our hospital. Furthermore, we did not explore the causes of death and are not able to determine if there were preventable or avoidable factors affecting mortality. The retrospective study setting is also a limitation since there might be factors which cannot have been observed and reported and might still have an impact on the survival. However, due to retrospective design the study protocol itself has not interfered in the treatment decisions or evaluation of treatment results. Thus, the study depicts reliably the real-life course of EVT for acute ischemic stroke.
Conclusion
According to the present results, the 30-day survivors of acute ischemic stroke treated with EVT have relatively good prognosis in the long-term follow-up. Comorbidity, functional dependency, stroke severity, and medical complications during the hospital stay were independently associated with the long-term mortality after EVT for stroke. These factors should be considered when evaluating stroke patients to meet eligibility for acute stroke interventions.
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Article Info
Publication History
Published online: October 15, 2022
Accepted:
October 10,
2022
Received in revised form:
September 28,
2022
Received:
June 1,
2022
Identification
DOI: https://doi.org/10.1016/j.jstrokecerebrovasdis.2022.106832
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© 2022 The Authors. Published by Elsevier Inc.
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