Browsing by Author "Brunser, Alejandro M."
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Item 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, RodrigoBackground: 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.Item 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, PabloPurpose 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.Item Exclusion Criteria for Intravenous Thrombolysis in Stroke Mimics: An Observational Study(2013) Brunser, Alejandro M.; Illanes, Sergio; Lavados, Pablo; Muñoz, Paula; Carcamo, Daniel; Hoppe, Arnold; Olavarria, Verónica; Delgado, Iris; Dıaz, VioletaBackground: 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 windowItem Incidence, risk factors, prognosis, and health-related quality of life after stroke in a low-resource community in Chile (ÑANDU): a prospective population-based study(2021) Lavados, Pablo; Hoffmeister, Lorena; Moraga, Ana M.; Vejar, Angélica; Vidal, Carolina; Gajardo, Constanza; Portales, María Bernardita; San Martín, Daniela; López, Eduardo; Rojo, Alexis; Olavarría, Verónica V.; Almeida, Juan; Brunser, Alejandro M.; Muñoz Venturelli, Paula; Hoppe, Arnold; Díaz, Violeta; Sacks, ClaudioBackground Stroke is a leading cause of disability and death worldwide. The best estimates of local, national, and global burden of stroke are derived from prospective population-based studies. We aimed to investigate the incidence, risk factors, long-term prognosis, care, and quality of life after stroke in the Ñuble region of Chile. Methods We did a prospective community-based study with use of multiple overlapping sources of hospitalised, ambulatory, and deceased cases. Standardised diagnostic criteria were used to identify and follow up all cases occurring in the resident population of the Ñuble region, Chile (in a low-income rural-urban population including predominantly people of Indigenous-European heritage), for 1 year. Participants were included if they had a clinical diagnosis of stroke confirmed according to the study criteria. All cases were adjudicated by vascular neurologists. Incidence rates of first-ever stroke were calculated from the population of Ñuble according to the 2017 national census. Findings From April 1, 2015, to March 31, 2016, we ascertained 1103 stroke cases, of which 890 (80·7%) were first-ever incident cases. The mean age of patients with first-ever stroke was 70·3 years (SD 14·1) and 443 (49·8%) were women. A CT scan was obtained in 801 (90%) of 890 patients (mean time from symptom onset to scan of 13·4 h (SD 29·8). The incidence of first-ever stroke age-adjusted to the world population was 121·7 (95% CI 113·7–130·1) per 100 000. The age-adjusted incidence rates, per 100000 inhabitants, by main pathological subtypes were as follows: ischaemic stroke (101·5 [95% CI 90·9–113·0]); intracerebral haemorrhage (17·9 [13·5–23·4]), and subarachnoid haemorrhage (4·2 [2·1–7·3]). The 30-day case-fatality rate was 24·6% (21·9–27·6). At 6 months after the stroke, 55·9% (432 of 773) of cases had died or were disabled, which increased to 61·0% (456 of 747) at 12 months. Health-related quality of life in survivors was low at 6 months, improving slightly at 12 months after the stroke. Interpretation The incidence of stroke in this low-resource population was higher than our previous finding in northern Chile and within the mid-range of most population-based stroke studies. This result was due mainly to a higher incidence of ischaemic stroke, probably associated with increasing age and a high prevalence of cardiometabolic risk factors in the population studied. Our findings suggest that more should be done for the prevention and care of stroke in communities like the Ñuble population. Funding The National Agency for Research and Development and the Technology-Health Research Fund, Clínica Alemana de Santiago, Boehringer Ingelheim, Bristol Meyers Squibb, The Herminda Martin Clinical Hospital of Chillán, Universidad Mayor, and Universidad de Concepción.Item Oxygen desaturation and adverse outcomes in acute stroke: Secondary analysis of the HeadPoST study(2021) Ouyang, Menglu; Roffe, Christine; Billot, Laurent; Song, Lili; Wang, Xia; Muñoz Venturelli, Paula; Lavados, Pablo; Robinson, Thompson; Middleton, Sandy; Olavarría, Verónica V.; Watkins, Caroline L.; Lee, Tsong-Hai; Brunser, Alejandro M.; Pontes-Neto, Octavio M.; Hackett, Maree L.Objective: Uncertainty exists over the prognostic significance of low arterial oxygen saturation (SaO2) in acute stroke. We aimed to determine the strength of association of SaO2 and adverse outcomes among participants of the international Head Positioning in acute Stroke Trial (HeadPoST). Methods: Post-hoc analyzes of HeadPoST, a pragmatic cluster-crossover randomized trial of lying flat versus sitting up head positioning in 11,093 patients (age ≥18 years) with acute stroke at 114 hospitals in 9 countries during 2015–2016. Associations of the lowest recorded SaO2 level, as a continuous measure and as a cut-point for desaturation (SaO2 <93%), in the first 24 h and clinical outcomes of death or dependency (modified Rankin scale [mRS] scores 3–6) and any serious adverse event (SAE) at 90 days, were assessed in generalized linear mixed models adjusted for baseline and in-hospital management confounders. Results: There was an inverse J-shaped association between SaO2 and death or dependency, with a nadir for optimal outcome at 96–97%. Patients with SaO2 desaturation were older, and had greater neurological impairment, premorbid disability and cardiorespiratory disease. Desaturation was not clearly associated with death or dependency (adjusted odds ratio [aOR] 1.19, 95% confidence interval [CI] 0.95–1.48) but was with SAEs (aOR 1.34, 95% CI 1.07–1.68), without heterogeneity by head position, cardiac-respiratory comorbidity, or other pre-specified subgroups. Conclusions: Any change in SaO2 outside of 96–97% is associated with poorer outcome after acute stroke. Clinical trial registration: HeadPoST is registered at ClinicalTrials.gov (NCT02162017).Item Risk Factors and Diet Components Determining Adherence to the Mediterranean Diet in Acute Ischemic Stroke Patients: A Cross-Sectional Analysis of a Prospective Hospital Register Study(2021) Olavarría, Verónica; Navia, Víctor; Mazzon, Enrico; Rojo, Alexis; Brunser, Alejandro M.; Lavados, PabloObjectives: Low adherence to a Mediterranean diet (MeDi) is associated with increased incidence, mortality, and severity of acute ischemic strokes (AIS). Nevertheless, the explanatory factors associated with such results are unclear. Our aim was to investigate stroke risk factors associated with adherence to a MeDi in a prospective cohort of AIS patients. Materials and Methods: Patients admitted from February 2017 to February 2020 were included in this study. Adherence was measured using the 14-point Mediterranean Diet Adherence Screener (MEDAS). Demographic and clinical characteristics were compared with adherence with a univariate analysis. A binomial regression was used to investigate the independent association of premorbid factors and MeDi compo- nents with adherence. Results: There were 413 patients. Mean age was 68.6 (17.4), 176 (42.6%) women. Median MEDAS score was 6 (IQR 47) points. 253 patients (61.2%) had a low adherence (MEDAS 6). In the univariate analysis, a low MEDAS was associated with lower education, diabetes, sedentary life- style, greater body mass index (BMI), lower alcohol consumption, and higher LDLc. In the regression analysis, younger age, lower education, functional dis- ability, hypertension, sedentary lifestyle, and higher BMI were associated with lower MEDAS scores. Six MeDi components had particularly low patient adherence: seafood, legumes, olive oil, nuts, wine, and fruit. Discussion: These data indicate low adherence to MeDi in younger patients who are less educated and have existing cardiovascular risk factors, in particular hypertension, sed- entary lifestyle, and higher BMI. Some components of the diet had a particu- larly low adherence. Conclusions: Tailoring diet prevention interventions to these specific populations, focusing on components with known less adher- ence, could improve adherence to a MeDi and the opportunity for secondary stroke prevention.Item Yield of Echocardiography in the Evaluation of Cerebral Ischemic Events: A Single Center Cohort Study(2019) Brunser, Alejandro M.; Ibañez-Arenas, Rodrigo; Larico, Martín; Mansilla, Eloy; Almeida, Juan; Olavarría, Verónica; Muñoz Venturelli, Paula; Rojo, Alexis; Cavada, Gabriel; Lavados, PabloBackground: Echocardiography (ECO) is frequently used as a screening test in patients with acute ischemic brain disease. We aimed to evaluate the additional information and therapeutic impact resulting from ECO in these patients. Methods: We conducted a prospective study performing ECO on consecutive patients with ischemic stroke or transient ischemic attacks, admitted to our centre between February 2013 and May 2017. Results: A total of 696 patients were included (female, 57.3%; mean age, 70 ± 15.3 years). Seven hundred thirty two echocardiographic examinations were performed (696 transthoracic and 36 transesophageal). Echocardiography yielded findings judged of clinical importance in 142 patients (20.4%, 95% CI 17.5-23.5). The most frequent of these were left atrial volume enlargement or a normal evaluation. Echocardiography findings resulted in changes in the management of 76 patients (10.7% 95% CI 8.8-13.4); initiation of anticoagulation therapy, administration of IV antibiotic therapy, cardiac surgeries, or other pharmacological therapies occurring in 42 cases (6%). The presence of coronary heart disease (OR: 2.64 95% CI 1.34-5.25), atrial fibrillation (OR: 0.24; 95% CI, 0.2-0.69), and admission NIHSS (OR: 1.04; 95% CI, 1.01-1.09), were the variables associated with changes in management. Conclusions: In unselected patients with acute ischemic stroke ECO had a low yield of additional information, and it changed management in a small percentage of patients.