Organized Comprehensive Stroke Center is Associated with Reduced Mortality: Analysis of Consecutive Patients in a Single Hospital / 대한뇌졸중학회지

BACKGROUND AND PURPOSE: Organized inpatient stroke care is one of the most effective therapies for improving patient outcomes. Many stroke centers have been established to meet this need, however, there are limited data on the effectiveness of these organized comprehensive stroke center (CSC) in the real-world setting. Our aim is to determine whether inpatient care following the establishment of CSC lowers mortality of patients with acute ischemic stroke (AIS). METHODS: Based on a prospective stroke registry, we identified AIS patients hospitalized before and after the establishment of a CSC. We observed all-cause mortality within 30 days from time of admission. Logistic regression was used to determine whether the establishment of the CSC affects independently the 30-day all-cause mortality. RESULTS: A total of 3,117 consecutive patients with AIS were admitted within seven days after the onset of the symptoms. Unadjusted 30-day mortality was lower for patients admitted to our hospital after the establishment of the CSC than before (5.9% vs. 8.2%, P=0.012). Advanced age, female gender, previous coronary artery disease, non-smoking, stroke subtype, admission on a holiday, referral from other hospitals, high NIHSS on admission, and admission before the establishment of CSC were associated with increased 30-day stroke case fatality. After adjustment for these factors, stroke inpatient care subsequent to the establishment of the CSC was independently associated with lower 30-day mortality (OR, 0.57; 95% CI, 0.412-0.795). CONCLUSIONS: Patients treated after the establishment of a CSC had lower 30-mortality rates than ever before, even adjusting for the differences in the baseline characteristics. The present study reveals that organized stroke care in a CSC might improve the outcome after AIS.

Aspirin Resistance May Not Be Associated with Clinical Outcome after Acute Ischemic Stroke: Comparison with Three Different Platelet Function Assays / 대한뇌졸중학회지

BACKGROUND: Aspirin resistance (AR) in platelet function assays showed substantial variation depending on the methods used to evaluate it. METHODS: In this study, we prospectively compared the results of Multiplate impedance platelet aggregometry (IPA) with those of light transmission aggregometry (LTA) and VerifyNow(R) system in determination of the prevalence of aspirin resistance (AR) and investigated the correlation between its presence and poor outcome (modified Rankin scale >2) in 105 patients with aspirin after acute ischemic stroke (AIS). RESULTS: After 5 days of using aspirin, 15 patients (14.3%) were classified as aspirin-resistance with the use of IPA, 24 patients (22.9%) by the LTA, and 14 patients (13.3%) by VerifyNow. Good agreement between the results of IPA and VerifyNow, was found (R=0.674, P<0.01). The concordance rate of AR detection was high between VerifyNow and IPA (k=0.72, P<0.01), albeit quite low between LTA and IPA. Regarding on its influence on clinical outcome after AIS, there wasn't any significant relationship between occurrence of poor outcome and the presence of AR in three platelet function assays. CONCLUSION: This study reveals that the incidence of AR in AIS might be highly test-specific. IPA seems to be similar to VerifyNow as a platelet function test.

The rCBV Ratio Is a Predictive Factor for Developing Malignant Middle Cerebral Artery Infarction within 6 Hours of Symptom Onset / 대한뇌졸중학회지

BACKGROUND: Malignant middle cerebral artery (MCA) infarction is one of the leading cause of death for patients with acute MCA infarction. We investigated the predicting factors for developing malignant MCA infarction (MMI) using multi-parametric magnetic resonance imaging (MRI). METHODS: We included 159 MCA infarction patients who visited Dong-A University Stroke Center from January 2007 to December 2010 and were diagnosed MCA occlusion within 6 hours after symptom onset. All patients underwent brain MRI including diffusion and perfusion-weighted image. The definition of the malignant MCA infarction is as follows: 1) deterioration of neurological symptoms and consciousness with clinical signs of uncal herniation, and 2) at least two-thirds of the MCA territory with compression of ventricles or midline shifting. The neurological deterioration was observed for 7 days. The severity of neurological symptom and clinical outcome were assessed by using National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS). RESULTS: Among 159 patients, 49 patients (30.8%) developed MMI. In a multivariate analysis, a larger diffusion volume on diffusion-weighted image, a lower regional cerebral blood volume (rCBV) ratio on perfusion-weighted image, and a higher NIHSS score on admission were identified as the predictive factors of MMI. The cut-off values of diffusion volume, NIHSS on admission and rCBV ratio were 69 mL, 15 points and 0.78. CONCLUSION: A large diffusion volume, a high NIHSS score and particularly a low rCBV ratio can predict a malignant course in MCA infarction within 6 hours of symptom onset in MCA occlusion.

Leukoaraiosis on Magnetic Resonance Imaging Is Related to Long-Term Poor Functional Outcome after Thrombolysis in Acute Ischemic Stroke

OBJECTIVE: Leukoaraiosis (LA) has been suggested to be related to the poor outcome or the occurrence of symptomatic intracerebral hemorrhage (sICH) after acute ischemic stroke. We retrospectively investigated the influences of LA on long-term outcome and the occurrence of sICH after thrombolysis in acute ischemic stroke (AIS). METHODS: In this study, we recruited 164 patients with AIS and magnetic resonance image (MRI)-detected thrombolysis. The presence and extent of LA were assessed using the Fazekas grading system. The National Institutes of Health Stroke Scale score was used to assess the baseline measure of neurologic severity, and the modified Rankin Scale score assessment was used up to 1 year after thrombolysis. RESULTS: Of 164 subjects, 56 (34.2%) showed LA on MRI. Compared to the 108 patients without LA, the patients with LA were of much older age (p<0.01), had a higher prevalence of hypertension (p<0.01), and had a much poorer outcome at 90 days (p=0.05) and 1 yr (p=0.01) after thrombolysis. There were no significant differences in sICH between patients with and without LA on MRI. In univariate analysis for the occurrence of poor outcome at 90 days after thrombolysis, the size of ischemic lesion on diffusion weighted images (DWI), [odds ratio (OR), 1.03; 95% confidence interval (95% CI), 1.01-1.04; p<0.01], recanalization (OR, 0.03; 95% CI, 0.01-0.10; p<0.01), sICH (OR, 12.2; 95% CI, 1.54-95.8), neurologic severity (OR, 1.17; 95% CI, 1.09-1.25; p<0.01), blood glucose level (OR, 1.01; 95% CI, 1.00-1.02; p=0.03), and the presence of LA on MRI (OR, 2.01; 95% CI, 1.04-3.01; p=0.04) were statistically significant. In multivariate analysis, neurologic severity (OR, 1.14; 95% CI, 1.04-1.24; p<0.01), recanalization (OR, 0.03; 95% CI, 0.01-0.11; p<0.01), lesion size on DWI (OR, 1.02; 95% CI, 1.01-1.03; p=0.02), serum glucose level (OR, 1.01; 95% CI; 1.01-1.02; p=0.03), and the presence of LA on MRI (OR, 3.2; 95% CI, 1.22-8.48; p<0.01) showed statistically significant differences. These trends persisted up to 1 yr after thrombolysis. CONCLUSION: In this study, we demonstrated that the presence of LA on MRI might be related to poor outcome after use of intravenous tissue plasminogen activator in AIS.

Prehospital Notification from the Emergency Medical Service Reduces the Transfer and Intra-Hospital Processing Times for Acute Stroke Patients

BACKGROUND AND PURPOSE: There is little information available about the effects of Emergency Medical Service (EMS) hospital notification on transfer and intrahospital processing times in cases of acute ischemic stroke. METHODS: This study retrospectively investigated the real transfer and imaging processing times for cases of suspected acute stroke (AS) with EMS notification of a requirement for intravenous (IV) tissue-type plasminogen activator (t-PA) and for cases without notification. Also we compared the intra-hospital processing times for receiving t-PA between patients with and without EMS prehospital notification. RESULTS: Between December 2008 and August 2009, the EMS transported 102 patients with suspected AS to our stroke center. During the same period, 33 patients received IV t-PA without prehospital notification from the EMS. The mean real transfer time after the EMS call was 56.0+/-32.0 min. Patients with a transfer distance of more than 40 km could not be transported to our center within 60 min. Among the 102 patients, 55 were transferred via the EMS to our emergency room for IV t-PA. The positive predictive value for stroke (90.9% vs. 68.1%, p=0.005) was much higher and the real transfer time was much faster in patients with an EMS t-PA call (47.7+/-23.1 min, p=0.004) than in those without one (56.3+/-32.4 min). The door-to-imaging time (17.8+/-11.0 min vs. 26.9+/-11.5 min, p=0.01) and door-to-needle time (29.7+/-9.6 min vs. 42.1+/-18.1 min, p=0.01) were significantly shorter in the 18 patients for whom there was prehospital notification and who ultimately received t-PA than in those for whom there was no prehospital notification. CONCLUSIONS: Our results indicate that prehospital notification could enable the rapid dispatch of AS patients needing IV t-PA to a stroke centre. In addition, it could reduce intrahospital delays, particularly, imaging processing times.