Background: For acute ischemic stroke (AIS) patients with history of prior stroke (PS) and diabetes mellitus (DM), intravenous recombinant tissue plasminogen activator (IV-tPA) therapy in the 3- to 4.5-hour window is off-label in Korea. This study aimed to assess the safety and efficacy of IV-tPA in these patients. Methods: Using data from a prospective multicenter stroke registry between January 2009 and March 2021, we identified AIS patients who received IV-tPA in the 3- to 4.5-hour window, and compared the outcomes of symptomatic intracranial hemorrhage (SICH), 3-month mortality, 3-month modified Rankin Scale (mRS) score 0-1 and 3-month mRS distribution between patients with both PS and DM (PS/DM, n=56) versus those with neither PS nor DM, or with only one (non-PS/DM, n=927). Results: The PS/DM group versus the non-PS/DM group was more likely to have a prior disability, hypertension, hyperlipidemia, coronary heart disease and less likely to have atrial fibrillation. The PS/DM and the non-PS/DM groups had comparable rates of SICH (0% vs. 1.7%; p>0.999) and 3-month mortality (10.7% vs. 10.2%; p=0.9112). The rate of 3-month mRS 0-1 was non-significantly lower in the PS/DM group than in the non-PS/DM group (30.4% vs. 40.7%; adjusted odds ratio [95% confidence interval], 0.81 [0.41-1.59]). Conclusions In the 3- to 4.5-hour window, AIS patients with PS/DM, as compared to those with non-PS/DM, might benefit less from IV-tPA. However, given the similar risks of SICH and mortality, IV-tPA in the late time window could be considered in patients with both PS and DM.

Background: To evaluate workload in emergency rooms (ERs) among clinical specialties including neurology and investigate characteristics of neurological consultations in ER. Methods: A nationwide survey was conducted to evaluate the number of specialists, resident physicians/surgeons, and emergency consultations of each clinical specialty in Korean tertiary referral hospitals from 2018 to 2019. Characteristics of neurological emergency consultations during the same period were investigated in one of the hospitals that participated. Results: A total of 23 hospitals were included. Four irrelevant clinical specialties were excluded. The number of neurology specialists and resident physicians were 12.5/hospital (4.1% of all specialists) and 6.4/hospital (3.4% of all resident physicians/surgeons), respectively, while the mean numbers of specialists and resident physicians or surgeons per clinical specialty were 13.7/hospital and 8.6/hospital, respectively. Neurological consultations accounted for 11.0% of all ER consultations for severe patients (Korean Triage and Acuity Scale level 1-3). Annual ER consultations for severe patients per neurology specialist was 274.1, which was only second to pediatrics (290.0). Annual ER consultations for severe patients per resident physician was 406.6 which was 1.6 times higher than the second highest (internal medicine, 247.0). Frequent conditions for neurological ER consultation were dizziness (24.8%), motor weakness (23.9%), headache (10.6%), dysarthria (9.9%), and seizures (7.7%). Frequent primary diagnoses were cerebrovascular diseases (29.0%) and episodic and paroxysmal disorders (24.9%). Conclusions Workloads of neurology specialists for ER consultation were significantly heavy, and the workload of neurology resident physicians was the heaviest among all specialties. This should be considered in health care policies.

Background: The association between endovascular treatment (EVT) case volume per hospital and clinical outcomes has been reported, but the exact volume threshold has not been determined. This study aimed to examine the case volume threshold in this context. Methods: National audit data on the quality of acute stroke care in patients admitted via emergency department, within 7 days of onset, in hospitals that treated ≥ 10 stroke cases during the audit period were analyzed. Ischemic stroke cases treated with EVT during the last three audits (2013, 2014, and 2016) were selected for the analysis. Annual EVT case volume per hospital was estimated and analyzed as a continuous and a categorical variable (in quartiles). The primary outcome measure was 1-year mortality as a surrogate of 3-month functional outcome. As post-hoc sensitivity analysis, replication of the study results was examined using the 2018 audit data. Results: We analyzed 1,746 ischemic stroke cases treated with EVT in 120 acute care hospitals. The median annual EVT case volume was 12.0 cases per hospital, and mortality rates at 1 month, 3 months, and 1 year were 12.7%, 16.6%, and 23.3%, respectively. Q3 and Q4 had 33% lower odds of 1-year mortality than Q1. Adjustments were made for predetermined confounders. Annual EVT case volume cut-off value for 1-year mortality was 15 cases per year (P < 0.02). The same cut-off value was replicated in the sensitivity analysis. Conclusion Annual EVT case volume was associated with 1-year mortality. The volume threshold per hospital was 15 cases per year.

This study aimed to present the prognosis after minor acute ischemic stroke (AIS) or transient ischemic attack (TIA), using a definition of subsequent stroke in accordance with recent clinical trials. In total, 9,506 patients with minor AIS (National Institutes of Health Stroke Scale ≤ 5) or high-risk TIA (acute lesions or ≥ 50% cerebral artery steno-occlusion) admitted between November 2010 and October 2013 were included. The primary outcome was the composite of stroke (progression of initial event or a subsequent event) and all-cause mortality. The cumulative incidence of stroke or death was 11.2% at 1 month, 13.3% at 3 months and 16.7% at 1 year. Incidence rate of stroke or death in the first month was 12.5 per 100 person-months: highest in patients with large artery atherosclerosis (17.0). The risk of subsequent events shortly after a minor AIS or high-risk TIA was substantial, particularly in patients with large artery atherosclerosis.

Purpose: To compare image quality in selective intracoronary contrast-injected computed tomography angiography (SelectiveCTA) with that in conventional intravenous contrast-injected CTA (IV-CTA). Materials and Methods: Six pigs (35 to 40 kg) underwent both IV-CTA using an intravenous injection (60 mL) and Selective-CTA using an intracoronary injection (20 mL) through a guide-wire during/after percutaneous coronary intervention. Images of the common coronary artery were acquired. Scans were performed using a combined machine comprising an invasive coronary angiography suite and a 320-channel multi-slice CT scanner. Quantitative image quality parameters of CT attenuation, image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), mean lumen diameter (MLD), and mean lumen area (MLA) were measured and compared. Qualitative analysis was performed using intraclass correlation coefficient (ICC), which was calculated for analysis of interobserver agreement. Results: Quantitative image quality, determined by assessing the uniformity of CT attenuation (399.06 vs. 330.21, p<0.001), image noise (24.93 vs. 18.43, p<0.001), SNR (16.43 vs. 18.52, p=0.005), and CNR (11.56 vs. 13.46, p=0.002), differed significantly between IV-CTA and Selective-CTA. MLD and MLA showed no significant difference overall (2.38 vs. 2.44, p=0.068, 4.72 vs. 4.95, p=0.078).The density of contrast agent was significantly lower for selective-CTA (13.13 mg/mL) than for IV-CTA (400 mg/mL). Agreement between observers was acceptable (ICC=0.79±0.08). Conclusion Our feasibility study in swine showed that compared to IV-CTA, Selective-CTA provides better image quality and requires less iodine contrast medium.

Background: Because Korea is the fastest aging country, the stroke incidence is increasing rapidly. We investigate the trend of the number of patients with acute stroke in recent years and estimate the burden of the neurologist to treat the acute stroke patient visited the emergency department. Methods: We requested a questionnaire survey to all teaching hospitals on the number of hospital beds, the number of stroke patients who visited the emergency department, the number of stroke patients in charge of the neurologist, and the number of days on duty of residents from 2016 to 2019. Results: Of 69 teaching hospitals, 41 hospitals answered the survey. The average hospital beds per hospital were increased annually from 909 to 916. The average patients who visited the emergency department with stroke and were in charged to neurologists were rapidly increased from 799 to 867 per hospital. In particular, the number of patients with hyperacute cerebral infarction requiring the thrombolytic administration or mechanical thrombectomy were rapidly increased from 105 to 131. On the other hand, the average number of residents per hospital was decreased from 5.1 to 4.8. Therefore, the days on duty per resident were increased from 74 to 77. Conclusions The number of acute stroke patients, especially, hyperacute stroke required the rapid cooperation and high labor were increasing rapidly in recent years. However, because the number of residents were decreased, the burden was increasing. To improve the quality of acute stroke treatment, it is necessary to increase the number of residents.

Background/Aims: There have been few multicenter studies on colonic polyps conducted by primary medical institutions. This study examined the detection rate of colonic polyps in primary health care institutions and the related factors while following the guidelines. Methods: The medical records of 14,029 patients who underwent colonoscopy between January-June 2020 at 40 primary medical institutions in Korea were analyzed. High-risk adenoma was defined as advanced adenoma, carcinoma, or ≥3 adenomas. Results: Most patients (71.2%) aged ≥50 years underwent re-colonoscopy within 5 years (51.3%) for diagnostic purposes (61.3%) in Korean primary medical institutions. The detection rates of colon polyps, adenoma, advanced adenoma, high-risk adenoma, and carcinoma was 59.9%, 38.9%, 5.9%, 11.4%, and 0.3% in all subjects and 59.8%, 37.5%, 8.5%, 12.9%, and 0.3% in average-risk patients, respectively. The incidences of adenoma in average-risk patients increased significantly with age (30s/40s/50s: 20.1%/29.4%/43% for adenoma, 4.4%/6.7%/10.3% for advanced adenoma, and 5.6%/9.5%/14.6% for high-risk adenoma; p<0.05). Before 50 years of age, high-risk adenoma was detected in 9.1% of patients in the first-time screening group, and the significant risk factors were being male and ≥40 years of age. The detection rate of high-risk adenoma in the normal index colonoscopy group within 5 years was 9.0%. The significant risk factors included older age, male sex, positive fecal occult blood test, stool form changes, and nonspecific symptoms (gas and indigestion). Conclusions More colonic adenoma studies targeting real-world clinical practice will be needed to revise the Korean guidelines for colorectal cancer screening and surveillance.