Hyun-Seok Park

A Systemized Stroke Code Significantly Reduced Time Intervals for Using Intravenous Tissue Plasminogen Activator under Magnetic Resonance Imaging Screening

BACKGROUNDnA stroke code can shorten time intervals until intravenous tissue plasminogen activator (IV t-PA) treatment in acute ischemic stroke (AIS). Recently, several reports demonstrated that magnetic resonance imaging (MRI)-based thrombolysis had reduced complications and improved outcomes in AIS despite longer processing compared with computed tomography (CT)-based thrombolysis.nnnMETHODSnIn January 2009, we implemented CODE RED, a computerized stroke code, at our hospital with the aim of achieving rapid stroke assessment and treatment. We included patients with thrombolysis from January 2007 to December 2008 (prestroke code period) and from January 2009 to May 2013 (poststroke code period). The IV t-PA time intervals and 90-day modified Rankin Scale (mRS) scores were collected.nnnRESULTSnDuring the observation period, 252 patients used IV t-PA under the CODE RED (MRI based: 208; CT based: 44). The remaining 71 patients (MRI based: 53; CT based: 18) received it before the implementation of our stroke code. After implementation of CODE RED, door-to-image time, door-to-needle time, and the onset-to-needle time were significantly reduced by 11, 18, and 22 minutes in MRI-based thrombolysis. Particularly, the proportion of favorable outcome (mRS score 0-2) was significantly increased (from 41.5% to 60.1%, P = .02) in poststroke than in prestroke code period in MRI-based thrombolysis. However, in ordinal regression, the presence of stroke code showed just a trend for favorable outcome (odds ratio, .99-2.87; P = .059) at 90 days of using IV t-PA after correction of age, sex, and National Institutes of Health Stroke Scale.nnnCONCLUSIONSnIn this study, we demonstrated that a systemized stroke code shortened time intervals for using IV t-PA under MRI screening. Also, our results showed a possibility that a systemized stroke code might enhance the efficacy of MRI-based thrombolysis. In the future, we need to carry out a more detailed prospective study about this notion.

Outcomes after Tissue Plasminogen Activator Administration under the Drip and Ship Paradigm May Differ According to the Regional Stroke Care System

The drip and ship paradigm for stroke patients enhances the rate of using intravenous tissue plasminogen activator (IVT) in community hospitals. The safety and outcomes of patients treated with IVT for acute ischemic stroke (AIS) under the drip and ship paradigm were compared with patients directly treated at a comprehensive stroke center in the Busan metropolitan area of Korea. This was a retrospective study of patients with AIS treated with IVT between January 2009 and January 2012. Information on patients baseline characteristics, neuroimaging, symptomatic intracerebral hemorrhage (sICH), and outcome 90xa0days after using IVT was obtained from our stroke registry. We surveyed stroke neurologists regarding their pattern of post-thrombolysis care. During the observation periods, we selected 317 patients using IVT. Among these, 239 patients received IVT at our stroke center, and 78 were treated at 21 community hospitals under the drip and ship paradigm. Initial neurologic deficits and the size of ischemic lesions on magnetic resonance imaging were much more severe in patients treated with IVT under the drip and ship paradigm compared with patients treated at our comprehensive stroke center. The prevalence of a poor outcome (modified Rankin Scale score 3-6) 90xa0days after IVT was much higher in patients treated with the drip and ship paradigm than in those treated at our comprehensive stroke center. Regarding the occurrence of sICH, there was no significant difference between the 2 groups. The clinical characteristics and outcomes after using IVT under the drip and ship paradigm may differ greatly among stroke care systems.

Impact of Prehospital Intervention on Delay Time to Thrombolytic Therapy in a Stroke Center with a Systemized Stroke Code Program

BACKGROUNDnThe use of emergency medical services (EMS) and notification to hospitals by paramedics for patients with suspected stroke are crucial determinants in reducing delay time to acute stroke treatment. The aim of this study is to investigate whether EMS use and prehospital notification (PN) can shorten the time to thrombolytic therapy in a stroke center with a systemized stroke code program.nnnMETHODSnBeginning in January 2012, stroke experts in our stroke center received direct calls via mobile phone from paramedics prenotifying the transport of patients with suspected stroke. We compared baseline characteristics and prehospital/in-hospital delay time in stroke patients treated with intravenous recombinant tissue plasminogen activator for 44 months with and without EMS use and/or PN.nnnRESULTSnIntravenous thrombolytic therapy was performed on 274 patients. Of those patients, 215 (78.5%) were transported to the hospital via EMS and 59 (21.5%) were admitted via private modes of transportation. The patients who used EMS had shorter median onset-to-arrival times (62 minutes versus 116 minutes, Pu2009<u2009.001). There was no difference in in-hospital delay time between the 2 groups. In 28 cases (13%) of EMS transport, EMS personnel called the clinical staff to notify the incoming patient. Prenotification by EMS was associated with shorter median door-to-imaging time (9 minutes versus 12 minutes, Pu2009=u2009.045) and door-to-needle time (20 minutes versus 29 minutes, Pu2009=u2009.011).nnnCONCLUSIONSnWe found that EMS use reduces prehospital delay time. However, EMS use without prenotification does not shorten in-hospital processing time in a stroke center with a systemized stroke code program.

The rCBV ratio on perfusion-weighted imaging reveals the extent of blood flow on conventional angiography after acute ischemic stroke

OBJECTIVEnIn this study, we evaluated the relationship between the rCBV (regional cerebral blood flow volume) ratio on perfusion-weighted imaging (PWI) and the extent of collateral flow on conventional angiography.nnnMETHODSnWe recruited 98 patients with AIS (within 24h after ischemic events). All the patients were evaluated by MRI, including PWI and diffusion-weighted imaging (DWI), and underwent digital subtraction angiography (DSA) of the brain. We hypothesized that the rCBV ratio on PWI could reveal the extent of the blood flow and predict early neurological deterioration (END) within 7 days after AIS.nnnRESULTSnThe rCBV ratio on PWI was significantly correlated with its extent on DSA (p<0.01). During the observation period, 24 patients (24.5%) experienced END. The univariate analysis revealed that severe neurological deficit at admission (p<0.01), the volume of the ischemic lesion on DWI (p<0.01), poor blood flow on DSA (p<0.01), the presence of DPM (p=0.05) and a low rCBV ratio on PWI (p<0.01) were related to END occurrence. The multivariate analysis showed that the presence of a low rCBV ratio on PWI was independently significant as a correlate of END (OR, 5.64; 95% CI, 1.68-18.90; p<0.01).nnnCONCLUSIONnThis study shows that the rCBV ratio on PWI may be a useful tool to reveal the status of blood flow after AIS. Moreover, the extent of collateral flow may be an important parameter that subtly influences the fate of DPM in AIS.

Prognostic factors for long-term poor outcomes after acute ischemic stroke in very old age (>80 years) patients: Total cholesterol level might differently influence long-term outcomes after acute ischemic stroke at ages above 80 years

We investigated the differences in determinant factors for functional outcomes between patients aged >80u2009years and those aged <80u2009years after acute ischemic stroke (AIS). In particular, we would like to know the differential impacts of initial total cholesterol (TC) levels between the two groups.

Pre-stroke glycemic control is associated with early neurologic deterioration in acute atrial fibrillation-related ischemic stroke

Background It has been suggested that AF-related ischemic stroke (IS) that is accompanied by atherosclerotic burden have poorer outcomes. The aim of this study was to investigate the importance of pre-stroke glycemic control (PSGC) on the early neurologic deterioration (END) of patients with acute AF-related IS. Methods We retrospectively recruited 121 patients with AF-related IS who also had Diabetes mellitus (DM). The HbA1C level was measured in all subjects. END was defined as an increase in the National Institute of Health Stroke Scale (NIHSS) score of 4 NIHSS points within 7 days of symptom onset compared to the initial NIHSS score. Results In this study, 20.7% (25 patients) were classified as having a poor PSGC status with a HbA1C level above 8.0%. In the univariate analysis, a poor PSGC status (p < 0.01), smoking (p = 0.01), severe neurologic deficits at admission (p = 0.01), and a larger size of ischemic lesions on DWI (p < 0.01) were associated with the occurrence of END. In the multivariate model, a poor PSGC status (p = 0.02) and larger size of ischemic lesions on MRI (p < 0.01) were independent predictors of END in acute AF-related IS. Conclusion The HbA1c level upon admission was independently associated with significant prediction of END in acute AF-related IS.

Relative CBV ratio on perfusion-weighted MRI indicates the probability of early recanalization after IV t-PA administration for acute ischemic stroke

Background We hypothesized that the relative cerebral blood volume (rCBV) ratio on perfusion-weighted imaging (PWI) using MRI might serve as a predictor of early recanalization (ER) after intravenous tissue plasminogen activator (IV t-PA) administration for acute ischemic stroke. Methods Patients with acute middle cerebral artery (MCA) ischemic stroke (IS) were enrolled in the study. They were evaluated by MRI, including PWI and diffusion-weighted imaging, before administration of IV t-PA and underwent digital subtraction angiography (DSA) of the brain within 2u2005h after t-PA administration. We compared the rCBV ratio on PWI between patients with and without ER on DSA and investigated the proportion of patients with an excellent outcome at 90u2005days after t-PA administration (modified Rankin Scale score 0–1) among those with and without ER. Results 85 patients with acute MCA IS were included; 16 patients (18.8%) experienced ER on DSA after IV t-PA administration. Patients with ER more frequently had an excellent outcome at 90u2005days than those without ER. The rCBV ratio on PWI was higher in the ER group (1.01±0.21, p<0.01) than in the non-ER group (0.82±0.18). After adjusting for the presence of atrial fibrillation and the serum glucose level, the rCBV ratio on PWI (OR 1.07; 95% CI 1.02 to 1.12; p<0.01) was a significant independent indicator of ER. Conclusions The results of this study suggest that the rCBV ratio on PWI might serve as a useful indicator of ER after IV t-PA administration.

The Processing Time for Recanalization and Size of Ischemic Lesions on DWI is Related With Complete Reperfusion After Mechanical Thrombectomy

Recent studies demonstrated that modified thrombolysis in cerebral infarction (TICI) 3 reperfusion have better functional outcomes than modified TICI 2b after mechanical thrombectomy in acute ischemic stroke with large vessel occlusion. The purpose of this study was to determine significant factors to forecast the presence of complete reperfusion after mechanical thrombectomy based on multimodal magnetic resonance imaging (MRI). We investigated 96 consecutive patients with acute large intracranial artery occlusion of anterior circulation who based on multimodal MRI. Also, we compared clinical and radiologic parameters between patients with modified TICI 3 and those with modified TICI 0-2b. Among 96 eligible subjects received mechanical thrombectomy, 39 patients (40.6%) showed complete reperfusion and 57 partial or nonreperfusion (mTICI 2b-26, mTICI 2a-9, mTICI 1-8, and mTICI 0-14) after mechanical thrombectomy. Patients with mTICI 3 had significantly smaller initial Diffusion weighted images (DWI) lesion volume (P < .01) and much shorter time interval from onset to reperfusion (P < .01) than those patients with mTICI (0-2b). In multivariate analysis, smaller initial DWI volume (odds ratio [OR], 1.78; 95% confidence interval [CI], 1.23-2.57; P < .01) and faster reperfusion time (OR, 1.07; 95% CI 1.01-1.14; P = .015) had an independence significance for complete reperfusion after mechanical thrombectomy. In this study, the ischemic lesion volume on DWI and faster processing time are critical factor to predict the state of complete reperfusion after mechanical thrombectomy.

Thrombolysis in Large Diffusion-Weighted Imaging Lesions: Lower Chance but Still a Chance

BACKGROUNDnWe sought to investigate whether early thrombolytic treatment can result in favorable functional outcome even in patients with large diffusion-weighted imaging (DWI) lesions.nnnMATERIALS AND METHODSnWe analyzed 566 patients who received intravenous alteplase within 4.5 hours from onset, initially underwent DWI and magnetic resonance angiography, and had acute infarction confined to anterior circulation. DWI lesion volumes were measured semiautomatically. The association between DWI lesion volume and 3-month outcome in patients who achieved early recanalization was assessed. The DWI lesion volume cutoff, which predicts unfavorable outcome despite recanalization, was determined. In patients with large DWI lesions, the distributions of modified Rankin Scale (mRS) score were compared according to the recanalization status.nnnRESULTSnFour hundred thirty-six patients achieved early recanalization. Among these patients, 283 (65%) patients had a favorable functional outcome (mRS score 0-2). DWI lesion volume (odds ratio [OR], 1.38 per 10u2009mL; 95% confidence interval [CI], 1.22-1.56) was an independent variable associated with poor outcome, along with hypertension (OR, 1.87; 95% CI, 1.12-3.10), National Institutes of Health Stroke Scale (NIHSS) score (OR, 1.13; 95% CI, 1.08-1.19), and onset-to-needle time (OR, 1.08 per 10 minutes; 95% CI, 1.03-1.13). The DWI lesion of 60u2009mL or higher highly predicted an unfavorable outcome with a positive predictive value of 95.3%. In patients with a DWI lesion of 60u2009mL or higher, recanalization had no benefit for an mRS score of 0-2 but was significantly associated with an mRS score of 0-3 (OR, 4.64; 95% CI, 1.08-19.97).nnnCONCLUSIONSnDespite early recanalization, the probability of favorable outcome is low in patients with a DWI lesion of 60u2009mL or higher. Nevertheless, the benefit of recanalization still persists in large DWI lesions.

Factors associated with early dramatic recovery following successful recanalization of occluded artery by endovascular treatment in anterior circulation stroke

Endovascular treatment (EVT) significantly increases the recanalization rate and improves functional outcomes in acute ischemic stroke. However, despite successful recanalization by EVT, some stroke patients demonstrate no early dramatic recovery (EDR). We assessed factors associated with EDR following recanalization by EVT. We included subjects with anterior circulation stroke treated with EVT who met the following criteria: Thrombolysis in Cerebral Ischemia scores (TICI) 2b-3 after EVT, lesion volume <70mL as seen on the pre-treatment diffusion-weighted imaging (DWI) scan and a baseline NIHSS score ≥6. EDR was defined as a ≥8-point reduction in the NIHSS score, or NIHSS score of 0 or 1 measured 24h following treatment. Multivariate regression analyses were performed to identify the predictors associated with EDR. Of the 102 patients (mean age, 64.3years; median National Institutes of Health Stroke Scale score, 14), EDR was achieved in 39 patients (38.2%). The median DWI lesion volume was 12mL (interquartile range, 5-25mL). Median onset-to-recanalization time in these patients was 320min (interquartile range, 270-415min). Logistic regression analysis identified a higher initial NIHSS score (OR 1.17, 95% CI 1.03-1.33, P=0.016) and shorter time from onset to recanalization (OR 0.99, 95% CI 0.986-0.997, P=0.003), to be independently associated with EDR. In the setting of pretreatment DWI lesion volume <70mL, a higher initial NIHSS score and faster time from onset to recanalization may be important predictors of EDR following successful EVT.