DSpace Repository :: Browsing by Author "Olavarría, Verónica"

Browsing by Author "Olavarría, Verónica"

Now showing 1 - 20 of 37

Accuracy of diffusion-weighted imaging in the diagnosis of stroke in patients with suspected cerebral infarct
(American Heart Association, 2013) Brunser, Alejandro; Hoppe, Arnold; Illanes, Sergio; Díaz, Violeta; Muñoz, Paula; Cárcamo, Daniel; Olavarría, Verónica; Valenzuela, Marcela; Lavados, Pablo
BACKGROUND AND PURPOSE: The accuracy of diffusion-weighted imaging (DWI) for the diagnosis of acute cerebral ischemia among patients with suspected ischemic stroke arriving to an emergency room has not been studied in depth. METHODS: DWI was performed in 712 patients with acute or subacute focal symptoms that suggested an acute ischemic stroke (AIS), 609 of them with AIS. RESULTS: DWI demonstrated a sensitivity of 90% and specificity of 97%, a positive likelihood ratio of 31 and a negative likelihood ratio of 0.1 for detecting AIS. The overall accuracy was 95%. Of those patients who demonstrated abnormal DWI studies, 99.5% were AIS patients, and of those patients with normal DWI studies 63% were stroke mimics. CONCLUSIONS: DWI is accurate in detecting AIS in unselected patients with suspected AIS; a negative study should alert for nonischemic conditions.
Accuracy of Power Mode TranscranialDoppler in the Diagnosis of Brain Death
(2015) Brunser, Alejandro; Lavados, Pablo; Cárcamo, Daniel; Hoppe, Arnold; Olavarría, Verónica; López, Javiera; Muñoz, Paula; Rivas, Rodrigo
Background:The diagnosis of brain death (BD) is complex. For this reason, we aimed toevaluate the accuracy of power mode transcranial Doppler (PMD-TCD) in diagnosing BD.Patients and methods:Patients admitted to an intensive care unit between December 2003and January 2012 were included in this study if they were in a structural coma, had nocraniectomy, and were evaluated blind by a neurologist using PMD-TCD. The diagnosis of BDwas based on an evaluation that took into consideration the absence of sedative drugs, amedian blood pressure>60 mmHg, a body temperature>35 C, and the absence of brainstemreflexes. A neurosonologist followed a protocol using PMD-TCD that considered the examina-tion as positive for brain circulatory arrest given the presence of reverberating, small systolicpeaks or the disappearance of a previous signal present in both middle cerebral arteries andintracranial vertebral arteries.Results:A total of 74 patients were evaluated. In 61 (82.4%) patients the interval betweenboth evaluations was less than 1 hour. The sensitivity and specificity for the diagnosis of BD with PMD-TCD were 100% and 98%, respectively. The positive and negative likelihood ratios forBD were 45 and 0, respectively.Conclusion:PMD-TCD is accurate for the diagnosis of BD.
Additional Information Given to a Multimodal Imaging Stroke Protocol by Transcranial Doppler Ultrasound in the Emergency Room: A Prospective Observational Study
(2010) Brunser, Alejandro M.; Lavados, Pablo; Cárcamo, Daniel A.; Hoppe, Arnold; Olavarría, Verónica; Diaz, Violeta; Rivas, Rodrigo
Background: Transcranial Doppler (TCD) ultrasound can demonstrate dynamic information. We aimed to evaluate whether TCD generates useful additional information in the emergency room after a multimodal stroke imaging protocol and also whether this modified the management of patients with cerebral infarction. Methods: Patients admitted between April 2006 and June 2007 with ischemic stroke of less than 24 h were subjected to a protocol consisting of non-contrast brain CT, computed tomography angiography, diffusion-weighted magnetic resonance imaging and then TCD within the following 6 h by an observer blinded to the results of imaging studies. Results: Seventy-nine patients were included. The imaging protocol was performed 457 (+/-346) min after stroke symptoms and TCD after 572 (+/-376) min. TCD provided additional information in 28 cases (35.4%, 95% CI 25.7-46.4). More that one piece of additional information was obtained in 6 patients. The most frequent additional information was collateral pathways. Multivariate analysis demonstrated that intracranial vessel occlusion was the variable most associated with additional information. In 7 patients (8.8%, 95% CI 4.3-17.1), additional information changed management: in 4 an additional angiography was performed, in 2 patients angiography was suspended and in 1 aggressive neurocritical care was indicated. Patients with NIHSS >10 were significantly more likely to have their initial treatment changed (p = 0.004). Conclusions: TCD can provide additional information to a multimodal acute ischemic stroke imaging protocol in a third of patients. This can result in changes in the management in some of these patients.
Cluster-Randomized, Crossover Trial of Head Positioning in Acute Stroke
(Massachusetts Medical Society, 2017) Anderson, Craig; Arima, Hisatomi; Lavados, Pablo; Billot, Laurent; Hackett, Maree; Olavarría, Verónica; Muñoz Venturelli, Paula; Brunser, Alejandro; Peng, Bin; Cui, Liying; Song, Lily; Rogers, Kris; Middleton, Sandy; Lim, Joyce Y.; Forshaw, Denise; Lightbody, Elizabeth; Woodward, Mark; Pontes-Neto, Octavio; De Silva, Asita; Lin, Ruey-Tay; Lee, Tsong-Hai; Pandian, Jeyaraj D.; Mead, Gillian E.; Robinson, Thompson; Watkins, Caroline; HeadPoST Investigators and Coordinators
BACKGROUND: The role of supine positioning after acute stroke in improving cerebral blood flow and the countervailing risk of aspiration pneumonia have led to variation in head positioning in clinical practice. We wanted to determine whether outcomes in patients with acute ischemic stroke could be improved by positioning the patient to be lying flat (i.e., fully supine with the back horizontal and the face upwards) during treatment to increase cerebral perfusion. METHODS: In a pragmatic, cluster-randomized, crossover trial conducted in nine countries, we assigned 11,093 patients with acute stroke (85% of the strokes were ischemic) to receive care in either a lying-flat position or a sitting-up position with the head elevated to at least 30 degrees, according to the randomization assignment of the hospital to which they were admitted; the designated position was initiated soon after hospital admission and was maintained for 24 hours. The primary outcome was degree of disability at 90 days, as assessed with the use of the modified Rankin scale (scores range from 0 to 6, with higher scores indicating greater disability and a score of 6 indicating death). RESULTS: The median interval between the onset of stroke symptoms and the initiation of the assigned position was 14 hours (interquartile range, 5 to 35). Patients in the lying-flat group were less likely than patients in the sitting-up group to maintain the position for 24 hours (87% vs. 95%, P<0.001). In a proportional-odds model, there was no significant shift in the distribution of 90-day disability outcomes on the global modified Rankin scale between patients in the lying-flat group and patients in the sitting-up group (unadjusted odds ratio for a difference in the distribution of scores on the modified Rankin scale in the lying-flat group, 1.01; 95% confidence interval, 0.92 to 1.10; P=0.84). Mortality within 90 days was 7.3% among the patients in the lying-flat group and 7.4% among the patients in the sitting-up group (P=0.83). There were no significant between-group differences in the rates of serious adverse events, including pneumonia. CONCLUSIONS: Disability outcomes after acute stroke did not differ significantly between patients assigned to a lying-flat position for 24 hours and patients assigned to a sitting-up position with the head elevated to at least 30 degrees for 24 hours. (Funded by the National Health and Medical Research Council of Australia; HeadPoST ClinicalTrials.gov number, NCT02162017.)
Determinantes del tiempo puerta-aguja en trombolisis endovenosa en el infarto cerebral, experiencia de un centro
(2020) Brunser, Alejandro; Mazzon, Enrico; Muñoz, Paula; Hoppe, Arnold; Lavados, Pablo; Rojo, Alexis; Navia, Víctor; Cavada, Gabriel; Olavarría, Verónica; Mansilla, Eloy
Background: Intravenous thrombolysis (IT) in acute ischemic stroke (AIS) is time dependent. The time elapsed from hospital admission to the thrombolytic bolus is named door to needle time (DNT) and is recommend to be of less than 60 min. Aim: To describe the DNT in our center and determine those factors associated with a DNT longer than 60 min. Material and Methods: Prospective analysis of patients treated with IT at a private hospital between June 2016 and June 2019. The percentage of patients with DNT exceeding 60 min, and the causes for this delay were evaluated. Results: IT was used in 205 patients. DNT was 43.6 ± 23.8 min. Forty patients (19.5% (95% CI, 14.4-25.7), had a DNT longer than 60 min. Uni-varied analysis demonstrated that AIS with infratentorial symptomatology (ITS), was significantly associated with DNTs exceeding 60 min. A history of hypertension, a higher NIH Stroke Scale score, the presence of an hyperdense sign in brain tomography (p = 0.001) and the need for endovascular therapy (p = 0.019), were associated with DNT shorter than 60 min. Multivariate analysis ratified the relationship between ITS and DNT longer than 60 min (Odds ratio: 3.19, 95% confidence intervals 1.26-8). Conclusions: The individual elements that correlated with a DNT longer than 60 min were the failure to detect the AIS during triage and doubts about its diagnosis
Diagnostic accuracy of a simple clinical score to screen for vascular abnormalities in patients with intracerebral hemorrhage.
(Elsevier, 2014) Olavarría, Verónica; Bustamante, Gonzalo; López, Mirta; Lavados, Pablo
BACKGROUND: Patients with intracerebral hemorrhage may have vascular abnormalities. There is no consensus about which patients should be studied with angiographic methods. Our aim was to derive a simple clinical score to screen for vascular abnormalities in intracerebral hemorrhage (ICH) and test its accuracy. METHODS: The data were extracted from 2 different registries of patients with ICH. Variables associated with a vascular abnormality were studied in the derivation cohort. We derived a scale by assigning scores to the degree of association. We applied the score to the validation cohort and calculated sensitivity, specificity, positive and negative predictive values, positive and negative likelihood ratios (LRs), receiver operating curves (ROC) and area under the curve (AUC). RESULTS: The performance of the scale in the derivation cohort showed the maximum operating point (MOP) at ≥5 (sensitivity .77, specificity .5). In the validation cohort, the MOP was a cutoff point of ≥5 (sensitivity .76, specificity .467). The positive and negative LRs were 2.1 and .6, respectively. The ROC showed similar AUC for both cohorts: .7. The probability of a vascular malformation was 23% with scores ≤5 and 83% with scores ≥9 in the validation cohort. CONCLUSIONS: This simple clinical score can be used immediately on diagnosing an ICH to decide accurately whether to perform an angiographic study or not. Further studies using this simple score should be used to validate it in larger prospective unselected cohorts and consecutive patients.
Did COVID-19 impact stroke services? A multicenter study
(2022) Shokri, Hossam; El Nahas, Nevine; El Basiony, Ahmed; Nguyen, Thanh; Abdalkader, Mohamad; Klein, Piers; Lavados, Pablo; Olavarría, Verónica; Amaya, Pablo; Llanos, Natalia; Brola, Waldemar; Michał, Lipowski; Melgarejo, Donoband; Cardozo, Analia; Caballero, Cesar; Pedrozo, Fatima; Rahman, Aminur; Hokmabadi, Elyar; Jalili, Javad; Farhoudi, Mehdi; Aref, Hany; Roushdy, Tamer
Background: It has been reported that acute stroke services were compromised during COVID-19 due to various pandemic-related issues. We aimed to investigate these changes by recruiting centers from different countries. Methods: Eight countries participated in this cross-sectional, observational, retrospective study by providing data from their stroke data base. We compared 1 year before to 1 year during COVID-19 as regards onset to door (OTD), door to needle (DTN), door to groin (DTG), duration of hospital stay, National Institute of Health Stroke Scale (NIHSS) at baseline, 24 h, and at discharge as well as modified Rankin score (mRS) on discharge and at 3 months follow-up. Results: During the pandemic year, there was a reduction in the number of patients, median age was significantly lower, admission NIHSS was higher, hemorrhagic stroke increased, and OTD and DTG showed no difference, while DTN time was longer, rtPA administration was decreased, thrombectomy was more frequent, and hospital stay was shorter. mRS was less favorable on discharge and at 3 months. Conclusion: COVID-19 showed variable effects on stroke services. Some were negatively impacted as the number of patients presenting to hospitals, DTN time, and stroke outcome, while others were marginally affected as the type of management.
Diffusion-weighted imaging as predictor of acute ischemic stroke etiology
(2021) Brunser, Alejandro; Mansilla, Eloy; Navia, Victor; Mazzon, Enrico; Rojo, Alexis; Cavada, Gabriel; Olavarría, Verónica; Muñoz Venturelli, Paula; Manuel, Pablo
Background: Topographic patterns may correlate with causes of ischemic stroke. Objective: To investigate the association between diffusionweighted imaging (DWI) and Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification. Methods: We included 1019 ischemic stroke patients. DWI were classified as: i) negative; ii) DWI single lesion (cortico-subcortical, cortical, subcortical ≥20 mm, or subcortical <20 mm); iii) scattered lesions in one territory (small scattered lesions or confluent with additional lesions); and iv) multiple lesions (multiple unilateral anterior circulation [MAC], multiple posterior circulation [MPC], multiple bilateral anterior circulation [MBAC], and multiple anterior and posterior circulations [MAP]). Results: There was a relationship between DWI patterns and TOAST classification (p<0.001). Large artery atherosclerosis was associated with small, scattered lesions in one vascular territory (Odds Ratio [OR] 4.22, 95% confidence interval [95%CI] 2.61–6.8), MPC (OR 3.52; 95%CI 1.54–8.03), and subcortical lesions <20 mm (OR 3.47; 95%CI 1.76–6.85). Cardioembolic strokes correlated with MAP (OR 4.3; 95%CI 1.64–11.2), cortico-subcortical lesions (OR 3.24; 95%CI 1.9–5.5) and negative DWI (OR 2.46; 95%CI 1.1–5.49). Cryptogenic strokes correlated with negative DWI (OR 4.1; 95%CI 1,84–8.69), cortical strokes (OR 3.3; 95%CI 1.25–8.8), MAP (OR 3.33; 95%CI 1.25–8.81) and subcortical lesion ≥20 mm (OR 2.44; 95%CI 1,04–5.73). Lacunar strokes correlated with subcortical lesions diameter <20 mm (OR 42.9; 95%CI 22.7–81.1) and negative DWI (OR 8.87; 95%CI 4.03–19.5). Finally, MBAC (OR 9.25; 95%CI 1.12–76.2), MAP(OR 5.54; 95%CI 1.94–15.1), and MPC (OR 3.61; 95%CI 1.5–8.7) correlated with stroke of other etiologies. Conclusions: A relationship exists between DWI and stroke subtype.
Diffusion-weighted imaging determinants for acute ischemic stroke diagnosis in the emergency room
(2018) Brunser, Alejandro M.; Cavada, Gabriel; Muñoz Venturelli, Paula; Olavarría, Verónica; Rojo, Alexis; Almeida, Juan; Díaz, Violeta; Hoppe, Arnold; Lavados, Pablo
Purpose The aim of this study was to investigate the clinical-radiological determinants of diffusion-weighted image (DWI) abnormalities in patients with suspected acute ischemic stroke (AIS) seen at the emergency room (ER). Methods During the study period, 882 consecutive patients were screened at Clínica Alemana de Santiago, Chile; 786 had AIS and 711 (90.4%) were included. Results DWI demonstrated 87.3% sensitivity and 99.0% specificity, with a positive likelihood ratio of 79 and a negative likelihood ratio of 0.13 for the detection of AIS. In the univariate analysis, a positive DWI in AIS was associated with admission National Institute of Health Stroke Scale (NIHSS) score (OR 1.09, 95% CI 1.04–1.1%), time from symptom onset to DWI (OR 1.03, 95% CI 1.01–1.05), presence of a relevant intracranial artery occlusion (OR 3.18, 95% CI 1.75–5.76), posterior circulation ischemia (OR 0.44, 95% CI 0.28–0.7), brainstem location of the AIS (OR 0.16, 95% CI 0.093–0.27), infratentorial location of AIS (OR 0.44, 95% CI 0.28–0.70), and lacunar (OR 0.27, 95% CI 0.11–0.68) or undetermined stroke etiology (OR 0.12, 95% CI 0.3–0.31). In multivariate analysis, only admission NIHSS score (OR 1.07, 95% CI 1.01–1.13), time from symptom onset to DWI (OR 1.04, 95% CI 1.01–1.13), brainstem location (OR 0.13, 95% CI 0.051–0.37), and lacunar (OR: 0.4, 95% CI 0.21–0.78) or undetermined etiology (OR: 0.4, 95% CI 0.22–0.78) remained independently associated. Conclusion DWI detects AIS accurately; the positivity of these evaluations in the ER is associated only with NIHSS on admission, time to DWI, brainstem location, and AIS etiology.
Dysphagia screening and risks of pneumonia and adverse outcomes after acute stroke: An international multicenter study
(Sage, 2019-06) Ouyang, Menglu; Boaden, Elizabeth; Arima, Hisatomi; Lavados, Pablo; Billot, Laurent; Hackett, Maree; Olavarría, Verónica; Muñoz Venturelli, Paula; Song, Lili; Rogers, Kris; Middleton, Sandy; Pontes-Neto, Octavio; Lee, Tsong-Hai; Watkins, Caroline; Robinson, Thompson; Anderson, Craig
Background Dysphagia is associated with aspiration pneumonia after stroke. Data are limited on the influences of dysphagia screen and assessment in clinical practice. Aims To determine associations between a “brief” screen and “detailed” assessment of dysphagia on clinical outcomes in acute stroke patients. Methods A prospective cohort study analyzed retrospectively using data from a multicenter, cluster cross-over, randomized controlled trial (Head Positioning in Acute Stroke Trial [HeadPoST]) from 114 hospitals in nine countries. HeadPoST included 11,093 acute stroke patients randomized to lying-flat or sitting-up head positioning. Herein, we report predefined secondary analyses of the association of dysphagia screening and assessment and clinical outcomes of pneumonia and death or disability (modified Rankin scale 3–6) at 90 days. Results Overall, 8784 (79.2%) and 3917 (35.3%) patients were screened and assessed for dysphagia, respectively, but the frequency and timing for each varied widely across regions. Neither use of a screen nor an assessment for dysphagia was associated with the outcomes, but their results were compared to “screen-pass” patients, those who failed had higher risks of pneumonia (adjusted odds ratio [aOR] = 3.00, 95% confidence interval [CI] = 2.18–4.10) and death or disability (aOR = 1.66, 95% CI = 1.41–1.95). Similar results were evidence for the results of an assessment for dysphagia. Subsequent feeding restrictions were related to higher risk of pneumonia in patients failed dysphagia screen or assessment (aOR = 4.06, 95% CI = 1.72–9.54). Conclusions Failing a dysphagia screen is associated with increased risks of pneumonia and poor clinical outcome after acute stroke. Further studies concentrate on determining the effective subsequent feeding actions are needed to improve patient outcomes.
Effects of an Avocado-based Mediterranean Diet on Serum Lipids for Secondary Prevention after Ischemic Stroke Trial (ADD-SPISE)
(2021) Olavarría, Verónica; Campodónico, Paola; Vollrath, Valeska; Von Geldern, Paula; Velásquez, Carolina; Pávez, Patricia; Valente, Bárbara; Donoso, Pamela; Ginesta, Alexandra; Cavada, Gabriel; Mazzon, Enrico; Navia, Víctor; Guzmán, Matías; Brinck, Pablo; Lavados, Pablo
Background: A poor or unhealthy diet is responsible for an important fraction of ischemic stroke risk. Adherence to dietary patterns, such as the Mediterranean diet, rich in monounsaturated fatty acids mainly from olive oil, is associated with a lower stroke risk. Furthermore, lowering low-density cholesterol (LDL-C) levels decreases stroke recurrence. Interestingly, Avocado-substituted diets, which are also rich in monounsaturated fatty acids, significantly decrease LDL cholesterol levels. This study aims to evaluate whether a Mediterranean diet based on Avocados reduces LDL-C compared to a low-fat high-complex carbohydrate diet after 3 months of the intervention in patients who had a recent acute ischemic stroke. The trial will also assess safety and feasibility. Patients and methods: Prospective, randomized open-label, blinded outcome assessment clinical trial. Participants are patients within a month of being admitted with an ischemic stroke, who consent and fulfil the eligibility criteria. Patients are randomly assigned to either diet intervention in a 1:1 ratio on top of the usual secondary prevention treatment. The intervention diet is: A)Avocado-based Mediterranean diet with intake of 1/2 portion of Avocado per day and B)The control diet is a low-fat high-complex carbohydrate diet. The main efficacy outcome is a reduction in plasma LDL-C levels at 3 months of the dietary intervention. Secondary outcomes include changes in the levels of serum lipid profile and serum inflammation markers, safety, and feasibility. A sample size of 200 patients was estimated to provide 80% power and 5% level of significance (10% loss and 5% crossover) to detect a minimum difference of 4.6 mg/dL in LDL-C after 3 months of intervention. Conclusion: We hypothesize that an Avocado-based Mediterranean diet will further reduce the levels of LDL-cholesterol at 3 months compared to the control diet, and that the intervention is safe and feasible.
Exclusion criteria for intravenous thrombolysis in stroke mimics: an observational study
(Elsevier, 2013) Brunser, Alejandro; Illanes, Sergio; Lavados, Pablo; Muñoz, Paula; Carcamo, Daniel; Hoppe, Arnold; Olavarría, Verónica; Delgado, Iris; Diaz, Violeta
BACKGROUND: Stroke mimics (SMs) are frequent in emergency departments (EDs), but are treated infrequently with intravenous recombinant tissue plasminogen activator (rt-PA) thrombolysis. We aimed at identifying the factors that lead to the exclusion of SMs from thrombolytic therapy. METHODS: Consecutive patients presenting to the ED between December 2004 and March 2011 with symptoms that suggested acute ischemic stroke were included. RESULTS: Eight hundred forty-two patients were included in this study; 113 (13.4%) were considered SMs; these patients were younger (P = .01), more frequently diabetic (P = .001), arrived later to the ED (P = .03), had lower National Institutes of Health Stroke Scale scores (P < .001), and higher frequencies of negative diffusion-weighted imaging studies (P = .002). The most common causes of cases of SM were toxic metabolic disorders (n = 34 [30.1%]) and seizures (n = 22 [19.5%]). The most frequent cause of consultation was aphasia (n = 43 [37.6%]). SM patients had a total of 152 contraindications for rt-PA, with 34 (30%) patients having >1 contraindication. The most frequent of these were being beyond the therapeutic window for thrombolysis (n = 96) and having deficits not measurable by the National Institutes of Health Stroke Scale or very mild symptoms before the start of rt-PA (n = 37). Twenty-four (21.2%) patients had both contraindications simultaneously. Two patients (1.76%) in the SM group were candidates for rt-PA but did not receive this treatment because they or their family rejected it. Of 729 stroke patients, 87 (11.9%) did receive rt-PA. CONCLUSIONS: SM patients frequently had exclusion criteria for systemic thrombolysis, the most frequent being presenting beyond the established thrombolytic window.
Frequency and Predictors of Major Bleeding in Patients With Embolic Strokes of Undetermined Source
(2020) Mikulík, Robert; Eckstein, Jens; Pearce, Lesly A.; Mundl, Hardi; Rudilosso, Salvatore; Olavarría, Verónica; Shoamanesh, Ashkan; Chamorro, Ángel; Martí-Fàbregas, Joan; Veltkamp, Roland; Öztürk, Şerefnur; Tatlisumak, Turgut; Peacock, W. Frank; Berkowitz, Scott D.; Connolly, Stuart J.; Hart, Robert G.
BACKGROUND AND PURPOSE: Risks, sites, and predictors of major bleeding during antithrombotic therapies have not been well defined for patients with recent embolic stroke of undetermined source. METHODS: Exploratory analysis of major bleeds defined by International Society of Thrombosis and Hemostasis criteria occurring among 7213 participants in international NAVIGATE (New Approach Rivaroxaban Inhibition of Factor Xa in a Global Trial) embolic stroke of undetermined source randomized trial comparing rivaroxaban 15 mg daily with aspirin 100 mg daily. RESULTS: During a median follow-up of 11 months, 85 major bleeds occurred. The most frequent site was gastrointestinal (38%), followed by intracranial (29%). Assignment to rivaroxaban (hazard ratio [HR], 2.7 [95% CI, 1.7–4.3]), East Asia region (HR, 2.5 [95% CI, 1.6–3.9]), systolic blood pressure ≥160 mmHg (HR, 2.2 [95% CI, 1.2–3.8]), and reduced estimated glomerular filtration rate (HR, 1.2 per 10 mL/min per 1.73 m2 decrease, [95% CI, 1.0–1.3]) were independently associated with presence of major bleeds. Five (6%) were fatal. Among 15 patients with intracerebral hemorrhage, 2 (13%) were fatal. There was no evidence of an early high-risk period following initiation of rivaroxaban. The annualized rate of intracerebral hemorrhage was 6-fold higher among East Asian participants (0.67%) versus all other regions (0.11%; HR , 6.3 [95% CI, 2.2–18.0]). Distribution of bleeding sites was similar for rivaroxaban and aspirin. CONCLUSIONS: Among embolic stroke of undetermined source patients participating in an international randomized trial, independent predictors of major bleeding were assignment to rivaroxaban, East Asia region, increased systolic blood pressure, and impaired renal function. East Asia as a region was strongly associated with risk of intracerebral hemorrhage. Estimated glomerular filtration rate should be a consideration for stratifying bleeding risk.
Global Impact of COVID-19 on Stroke Care and IV Thrombolysis
(2021) Nogueira, Raúl G.; Qureshi, Muhammad M.; Abdalkader, Mohamad; Martins, Sheila Ouriques; Yamagami, Hiroshi; Mansour, Ossama Yassin; Qiu, Zhongming; Sathya, Anvitha; Czlonkowska, Anna; Tsivgoulis, Georgios; Aguiar de Sousa, Diana; Demeestere, Jelle; Mikulik, Robert; Vanacker, Peter; Siegler, James E.; Kõrv, Janika; Biller, Jose; Liang, Conrad W.; Sangha, Navdeep S.; Zha, Alicia M.; Czap, Alexandra L.; Holmstedt, Christine Anne; Turan, Tanya N.; Ntaios, George; Malhotra, Konark; Tayal, Ashis; Loochtan, Aaron; Ranta, Annamarei; Mistry, Eva A.; Alexandrov, Anne W.; Huang, David Y.; Yaghi, Shadi; Raz, Eytan; Sheth, Sunil A.; Mohammaden, Mahmoud H.; Frankel, Michael; Bila Lamou, Eric Guemekane; Aref, Hany M.; Elbassiouny, Ahmed; Hassan, Farouk; Menecie, Tarek; Mustafa, Wessam; Shokr, Hossam M.; Roushdy, Tamer; Sarfo, Fred S.; Alabi, Tolulope Oyetunde; Arabambi, Babawale; Nwazor, Ernest O.; Sunmonu, Taofiki Ajao; Wahab, Kolawole; Yaria, Joseph; Hussein Mohammed, Haytham; Adebayo, Philip B.; Riahi, Anis D.; Sassi, Samia Ben; Navia, Víctor; Olavarría, Verónica
Objective To measure the global impact of COVID-19 pandemic on volumes of IV thrombolysis (IVT), IVT transfers, and stroke hospitalizations over 4 months at the height of the pandemic (March 1 to June 30, 2020) compared with 2 control 4-month periods. Methods We conducted a cross-sectional, observational, retrospective study across 6 continents, 70 countries, and 457 stroke centers. Diagnoses were identified by their ICD-10 codes or classifications in stroke databases. Results There were 91,373 stroke admissions in the 4 months immediately before compared to 80,894 admissions during the pandemic months, representing an 11.5% (95% confidence interval [CI] −11.7 to −11.3, p < 0.0001) decline. There were 13,334 IVT therapies in the 4 months preceding compared to 11,570 procedures during the pandemic, representing a 13.2% (95% CI −13.8 to −12.7, p < 0.0001) drop. Interfacility IVT transfers decreased from 1,337 to 1,178, or an 11.9% decrease (95% CI −13.7 to −10.3, p = 0.001). Recovery of stroke hospitalization volume (9.5%, 95% CI 9.2–9.8, p < 0.0001) was noted over the 2 later (May, June) vs the 2 earlier (March, April) pandemic months. There was a 1.48% stroke rate across 119,967 COVID-19 hospitalizations. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection was noted in 3.3% (1,722/52,026) of all stroke admissions. Conclusions The COVID-19 pandemic was associated with a global decline in the volume of stroke hospitalizations, IVT, and interfacility IVT transfers. Primary stroke centers and centers with higher COVID-19 inpatient volumes experienced steeper declines. Recovery of stroke hospitalization was noted in the later pandemic months.
Head position and cerebral blood flow in acute ischemic stroke patients: protocol for the pilot phase, cluster randomized, Head Position in Acute Ischemic Stroke Trial (HeadPoST pilot)
(Sage Publications, 2016) Brunser, Alejandro; Muñoz Venturelli, Paula; Lavados, Pablo; Gaete, Javier; Martins, Sheila; Arima, Hisatomi; Anderson, Craig; Olavarría, Verónica
RATIONALE: Few proven interventions exist for acute ischemic stroke (AIS), and most are expensive and restricted in applicability. Lying flat 'head down' positioning of AIS patients has been shown to increase by as much as 20%, mean cerebral blood flow velocities (CBFV) measured by transcranial Doppler (TCD) but whether this translates into clinical improvement is uncertain. AIM: To determine if the lying flat position increases mean CBFV in the affected territory as compared to the sitting up position in AIS patients. METHODS AND DESIGN: Head Position in Acute Ischemic Stroke Trial (HeadPoST pilot) is a cluster randomized (clusters being months), assessor-blinded end-point, phase IIb trial, where consecutive adults with anterior circulation AIS within 12 h of symptom onset are positioned to a randomized position for 48 h with TCD performed serially. STUDY OUTCOMES: Primary outcome is mean CBFV on TCD at 1 and 24 h after positioning. Secondary outcomes include: serious adverse events, neurological impairment at seven days, and death and disability at 90 days. SAMPLE SIZE ESTIMATES: Assuming an increase of 8.3 (SD 11.4) cm/s in average of mean CBFV when tilted from 30° to 0°, 46 clusters are required (92 patients in total) to detect a 20% increase of mean CBFV with 90% power and 5% level of significance. CONCLUSION: HeadPoST pilot is a cluster randomized multicenter clinical trial investigating the effect of head positioning on mean CBFV in anterior circulation AIS.
Head position and cerebral blood flow velocity in acute ischemic stroke: a systematic review and meta-analysis.
(Karger, 2014) Lavados, Pablo; Heritier, Stephane; Muñoz Venturelli, Paula; Brunser, Alejandro; Anderson, Craig; Arima, Hisatomi; Olavarría, Verónica
BACKGROUND: Patients with acute ischemic stroke (AIS) have impaired vasomotor reactivity, especially in the affected cerebral hemisphere, such that they may depend directly on systemic blood pressure to maintain perfusion to vulnerable 'at risk' penumbral tissue. As the sitting up position may affect cerebral perfusion by decreasing cerebral blood flow (CBF) in salvageable tissue, positioning AIS patients with their head in a lying flat position could increase CBF through collateral circulation or gravitational force. We wished to quantify the effect of different head positions on mean flow velocity (MFV) by transcranial Doppler ultrasonography (TCD) in AIS patients to assess the potential for benefit (or harm) of head positioning in a clinical trial. METHODS: We performed a systematic review and meta-analysis of observational studies with TCD to evaluate differences in cerebral MFV between the lying flat and sitting up head positions in AIS. For each study and each comparison, we obtained the mean value of changes in MFV and its variance. RESULTS: A total of 303 studies were identified, but 298 were excluded for varying reasons; 4 papers met the inclusion criteria and 57 patients were included in the meta-analysis for calculation of the overall mean difference in MFV. We found a significant increase in MFV from a bed angle of 30 to 15° (4.6 cm/s, 95% confidence interval, CI, 2.9-6.2, p < 0.001) and from 30 to 0° (8.3 cm/s, 95% CI 5.3-11.3, p < 0.001) in the affected hemisphere but not on the normal side in AIS patients. CONCLUSIONS: In AIS patients, MFV increased significantly in the side affected by the stroke but not in the unaffected side when they were positioned in a lying flat head position at 0 or 15° compared to an upright head position at 30°. The clinical significance of these findings is now undergoing further randomized evaluation in the international multicenter Head Position in Acute Stroke Trial (HeadPoST).
Head Position in Stroke Trial (HeadPoST) - sitting-up vs lying-flat positioning of patients with acute stroke: study protocol for a cluster randomised controlled trial
(Biomed Central Ltd., 2015) Muñoz, Paula; Arima, Hisatomi; Lavados, Pablo; Brunser, Alejandro; Peng, Bin; Cui, Liying; Song, Lily; Billot, Laurent; Boaden, Elizabeth; Hackett, Maree; Heritier, Stephane; Stephen, Jan; Middleton, Sandy; Olavarría, Verónica; Lim, Joyce; Lyndle, Richard; Heeley, Emma; Thompson, Robinson; Pontes, Octavio; Natsagdorj, Lkhamtsoo; Ruey-Tay, Lin; Watkins, Caroline; Anderson, Craig
BACKGROUND: Positioning a patient lying-flat in the acute phase of ischaemic stroke may improve recovery and reduce disability, but such a possibility has not been formally tested in a randomised trial. We therefore initiated the Head Position in Stroke Trial (HeadPoST) to determine the effects of lying-flat (0°) compared with sitting-up (≥ 30°) head positioning in the first 24 hours of hospital admission for patients with acute stroke. METHODS/DESIGN: We plan to conduct an international, cluster randomised, crossover, open, blinded outcome-assessed clinical trial involving 140 study hospitals (clusters) with established acute stroke care programs. Each hospital will be randomly assigned to sequential policies of lying-flat (0°) or sitting-up (≥ 30°) head position as a 'business as usual' stroke care policy during the first 24 hours of admittance. Each hospital is required to recruit 60 consecutive patients with acute ischaemic stroke (AIS), and all patients with acute intracerebral haemorrhage (ICH) (an estimated average of 10), in the first randomised head position policy before crossing over to the second head position policy with a similar recruitment target. After collection of in-hospital clinical and management data and 7-day outcomes, central trained blinded assessors will conduct a telephone disability assessment with the modified Rankin Scale at 90 days. The primary outcome for analysis is a shift (defined as improvement) in death or disability on this scale. For a cluster size of 60 patients with AIS per intervention and with various assumptions including an intracluster correlation coefficient of 0.03, a sample size of 16,800 patients at 140 centres will provide 90 % power (α 0.05) to detect at least a 16 % relative improvement (shift) in an ordinal logistic regression analysis of the primary outcome. The treatment effect will also be assessed in all patients with ICH who are recruited during each treatment study period. DISCUSSION: HeadPoST is a large international clinical trial in which we will rigorously evaluate the effects of different head positioning in patients with acute stroke.
Head Position in the Early Phase of Acute Ischemic Stroke: An International Survey of Current Practice
(National Stroke Association. Published by Elsevier Inc., 2015) Muñoz, Paula; Olavarría, Verónica; González, Francisca; Brunser, Alejandro; Lavados, Pablo; Arima, Hisatomi; Anderson, Craig
BACKGROUND: Evidence to recommend a specific head position for patients in the early phase of acute ischemic stroke (AIS) is scarce. The aim of this study was to assess current head position practice for AIS patients among physicians from hospitals in different countries. METHODS: A cross-sectional survey research design was used; physicians who are part of a stroke research network were invited to participate by e-mail. Descriptive statistics were used. RESULTS: An invitation to participate was delivered to 298 doctors from 16 countries and 42.9% completed all survey questions. Participant responses were evenly divided in sitting up and lying flat position as the most usual at their hospital: 52.8% (95% confidence interval [CI], 43.7-61.0) of respondents preferred sitting up, whereas 47.2% (95% CI, 38.2-55.5) preferred lying flat; 53.9% (95% CI, 45.3-62.5) of participants answered that no written protocol specifying the indicated head position for stroke patients was available at their hospital or department, and 71% (95% CI, 63.2-78.9) recognized being uncertain about the best position for AIS patients. CONCLUSIONS: Common practice differs between physicians, and there is a lack of consensus about the best strategy regarding head position for AIS patients in many countries. An opportunity exists for a randomized trial to resolve this uncertainty and develop evidence-based consensus protocols to improve patient management and outcomes.
Impact of Evidence-Based Stroke Care on Patient Outcomes: A Multilevel Analysis of an International study
(2019) Muñoz Venturelli, Paula; Li, Xian; Middleton, Sandy; Watkins, Caroline; Lavados, Pablo; Olavarría, Verónica; Brunser, Alejandro; Pontes-Neto, Octavio; Santos, Taiza; Hisatomi, Arima; Billot, Laurent; Hackett, Maree; Song, Lily; Robinson, Thompson; Anderson, Craig; HEADPOST, Head positioning in acute
Background-—The uptake of proven stroke treatments varies widely. We aimed to determine the association of evidence-based processes of care for acute ischemic stroke (AIS) and clinical outcome of patients who participated in the HEADPOST (Head Positioning in Acute Stroke Trial), a multicenter cluster crossover trial of lying flat versus sitting up, head positioning in acute stroke. Methods and Results-—Use of 8 AIS processes of care were considered: reperfusion therapy in eligible patients; acute stroke unit care; antihypertensive, antiplatelet, statin, and anticoagulation for atrial fibrillation; dysphagia assessment; and physiotherapist review. Hierarchical, mixed, logistic regression models were performed to determine associations with good outcome (modified Rankin Scale scores 0–2) at 90 days, adjusted for patient and hospital variables. Among 9485 patients with AIS, implementation of all processes of care in eligible patients, or “defect-free” care, was associated with improved outcome (odds ratio, 1.40; 95% CI, 1.18–1.65) and better survival (odds ratio, 2.23; 95% CI, 1.62–3.09). Defect-free stroke care was also significantly associated with excellent outcome (modified Rankin Scale score 0–1) (odds ratio, 1.22; 95% CI, 1.04–1.43). No hospital characteristic was independently predictive of outcome. Only 1445 (15%) of eligible patients with AIS received all processes of care, with significant regional variations in overall and individual rates. Conclusions-—Use of evidence-based care is associated with improved clinical outcome in AIS. Strategies are required to address regional variation in the use of proven AIS treatments.
In-Hospital Acute Ischemic Stroke is Associated with Worse Outcome: Experience of a Single Center in Santiago Chile
(2021) Brunser, Alejandro; Navia, Víctor; Araneda, Patricia; Mazzon, Enrico; Muñoz Venturelli, Paula; Cavada, Gabriel; Olavarría, Verónica; Lavados, Pablo
Objectives: In-hospital acute ischemic stroke (HIS) accounts for 217% of all acute ischemic strokes (AIS) seen in hospital and they have worse prognosis. In this study we aimed to identify the frequency of HIS and their characteristics in our center. Materials and Methods: Retrospective analysis of a prospective register of patients with AIS seen at Clínica Alemana de Santiago, between January 2017 and January 2019. HIS and community onset ischemic strokes patients (CIS) were compared, univariate analysis was performed, covariates with p < 0.25 were selected for multivariate analysis. Differences between, proportion of strokes treated with thrombolytic therapy, door to needle time were compared between HIS and CIS patients, as also mortality rates at 90 days. Results: During the study period 369 patients with AIS were seen; of these 20 (5.4%, 95 CI%, 3.58.2) corresponded to HIS. In univariate analysis, HIS compared to patients arriving form the community to the emergency room, suffered more frequently from, heart failure (p = 0.04), and active malignancies (p < 0.001). HIS patients had longer times from symptom onset to non-contrast brain tomography (540 §150 minutes); they were also less frequently treated with intravenous thrombolysis compared to community AIS: 15% versus 30% respectively (p = 0.08). Mortality rates at 90 days were higher in HIS: 30 versus 5% (p = 0.001). Conclusions: In this cohort, HIS patients suffered delays in their neuroimaging studies and received less intravenous thrombolysis; this underscores the need for a standardized approach to the recognition and management of inhospital acute ischemic stroke

Browsing by Author "Olavarría, Verónica"

Results Per Page

Sort Options