Bringing forth mathematical concepts: signifying sensorimotor enactment in fields of promoted action

Inspired by Enactivist philosophy yet in dialog with it, we ask what theory of embodied cognition might best serve in articulating implications of Enactivism for mathematics education. We offer a blend of Dynamical Systems Theory and Sociocultural Theory as an analytic lens on micro-processes of action-to-concept evolution. We also illustrate the methodological utility of design-research as an approach to such theory development. Building on constructs from ecological psychology, cultural anthropology, studies of motor-skill acquisition, and somatic awareness practices, we develop the notion of an “instrumented field of promoted action”. Children operating in this field first develop environmentally coupled motor-action coordinations. Next, we introduce into the field new artifacts. The children adopt the artifacts as frames of action and reference, yet in so doing they shift into disciplinary semiotic systems. We exemplify our thesis with two selected excerpts from our videography of Grade 4–6 volunteers participating in task-based clinical interviews centered on the Mathematical Imagery Trainer for Proportion. In particular, we present and analyze cases of either smooth or abrupt transformation in learners’ operatory schemes. We situate our design framework vis-à-vis seminal contributions to mathematics education research

Bringing forth mathematical concepts: signifying sensorimotor enactment in fields of promoted action

Inspired by Enactivist philosophy yet in dialog with it, we ask what theory of embodied cognition might best serve in articulating implications of Enactivism for mathematics education. We offer a blend of Dynamical Systems Theory and Sociocultural Theory as an analytic lens on micro-processes of action-to-concept evolution. We also illustrate the methodological utility of design-research as an approach to such theory development. Building on constructs from ecological psychology, cultural anthropology, studies of motor-skill acquisition, and somatic awareness practices, we develop the notion of an “instrumented field of promoted action”. Children operating in this field first develop environmentally coupled motor-action coordinations. Next, we introduce into the field new artifacts. The children adopt the artifacts as frames of action and reference, yet in so doing they shift into disciplinary semiotic systems. We exemplify our thesis with two selected excerpts from our videography of Grade 4–6 volunteers participating in task-based clinical interviews centered on the Mathematical Imagery Trainer for Proportion. In particular, we present and analyze cases of either smooth or abrupt transformation in learners’ operatory schemes. We situate our design framework vis-à-vis seminal contributions to mathematics education research

Primary PCI is still beneficial later than 24 hours after STEMI

Background: The impact of a mechanical reperfusion strategy beyond a 24-hour cut-off is still unsettled. Optimal management for these patients remains uncertain. Purpose: We sought to investigate the effect of delayed primary percutaneus coronary intervention (p-PCI) – 24 to 48 hours after symptom onset-for patients with ST-segment elevation myocardial infarction (STEMI) not undergoing timely reperfusion therapy. Methods: We conducted a cohort study of 1822 STEMI first-day survivors who were admitted with a diagnosis of STEMI, but did not receive any mechanical or pharmacological reperfusion therapy within 24 hours from symptom onset. We used multivariable logistic regression combined to landmark analysis to evaluate the effect of delayed p-PCI on in-hospital mortality and incidence of severe left ventricular dysfunction (LVD; ejection fraction<40%) at discharge. Patients who had routine medical treatment (RMT) and never received PCI served as controls. Data were adjusted for patient characteristics, concurrent medications and baseline risk status. Results: Patients undergoing delayed p-PCI had lower unadjusted in-hospital mortality (1.0% versus 6.2%, p<0.001) and incidence of severe LVD (19.6% versus 26.6%, p<0.05) than patients receiving RMT. Benefit of PCI remained significantly associated with mortality (OR: 0.32; 95% CI: 0.12–0.87) and LVD (OR:0.53; 95% CI: 0.33–0.87) after adjustment for baseline characteristics and concomitant medications. Benefit was greatest in the highest TIMI risk index patients where delayed p-PCI was associated with both a considerably lower risk of death (12.8% versus 2.5%; p<0.001) and a significant (p=0.04) reduction in the incidence of severe LVD (31.2% versus 23.1%). Conclusions: Patients not undergoing timely reperfusion therapy should be offered p-PCI on a liberal basis up to 48 hours from symptom onset

Gender differences on short term outcomes after contemporary percutaneous coronary intervention

Purpose: Conflicting information exists on sex-based differences in outcomes after percutaneous coronary intervention (PCI). In addition, previous data may not be reflective of the entire general clinical population, as most studies were post-hoc analyses of clinical trials with inherent possibility of a differential attrition rate in the pre-randomization phase by sex. Methods: We investigated the relationship between sex and the risks of shortclinical outcomes after PCI in current practice, using data on 13259 acute coronary syndromes (ACS) consecutive patients from January 2010 to January 2015. Patients treated in a conservative manner or with CABG were excluded, leaving a final study population of 7792 patients who underwent PCI (28.7% were women). Cox proportional hazards regression model was adjusted to covariates significantly different between groups in univariate analysis. The primary endpoint was 30-days mortality; the secondary endpoint was the composite of cardiovascular mortality, stent thrombosis, stroke or major bleeding; the tertiary endpoint was left ventricular dysfunction (LVD) defined as an LV ejection fraction <40% at echocardiography Results: Women were older (mean age: 65.5 vs. 59.7 years, p<0.001), had higher rates of diabetes (30.9% vs. 22.0%, p<0.001), hypertension (77.8% vs. 65.6%, p<0.001), cerebrovascular disease (4.7% vs. 3.3%, p=0.003) and higher rates of Killip class ≥2 (25.1% vs. 19.6%, p<0.001), but lower rates of smoking (30.3% vs. 45.3%, p<0.001) than male patients. Unadjusted mortality was significantly higher in women than men (7.1% vs. 4.4%, p<0.001), as well as the overall the rates of the secondary endpoint (10.5% vs. 7.1%, p<0.001). No differences were observed in the unadjusted rates of the tertiary endpoint (19.1% vs. 21.2%, p=0.16). After multivariable adjustment, female sex was no longer associated with a higher risk of death (HR: 1.13, 95% CI: 0.87–1.48) and higher risk of secondary endpoint (HR: 1.18, 95% CI: 0.97–1.45). On the contrary female sex was associated with lower risk of LVD (adjusted HR: 0.73, 95% CI: 0.60–0.89). These sex-specific findings for outcomes were consistent across patient subgroups using bare metal stents (HR: 1.25, 95% CI: 0.88–1.77) or drug-eluting stents (HR: 1.13, 95% CI: 0.78–1.62). Conclusions: In our cohort, among patients undergoing contemporary PCI, no differences in short-terms major cardiovascular outcomes were observed between women and men. Women undergoing PCI has a lower risk of LVD than men. There was no association between sex and stent type on short-term outcomes

Inaccurate treatment and poor outcome in patients with ACS and atypical symptoms

Purpose: We explored clinical characteristics and outcome associated with atypical chest pain (CP) in patients with diagnosis of ACS. Methods: Data of 8947 patients (32.4% women) from the International Survey of Acute Coronary Syndrome in Transitional Country (ISACS-TC) were reviewed in our comprehensive coordinating center. Only patients with admission and discharge diagnosis of ACS were considered. Results: There were 778 patients with atypical CP for the index event. These patients were significantly (p12 hrs to arrive to hospital; absence of typical CP doubled the probability (OR: 2.18; CI: 1.89–2.55) to late hospital presentation. Interestingly, patients without typical CP were significantly more likely to exhibit signs of heart faliure (42.8% vs. 22.1%), although they less frequently had STEMI as index even. In-hospital mortality rate was in the overall cohort 8.2% (STEMI: 9.1%, NSTEMI: 8.8%, UA: 2.1%). Yet, the mortality was significantly greater for patients with atypical CP (STEMI: 19.8%, NSTEMI: 19.3%) than for those with typical CP (STEMI: 6.7%, NSTEMI: 7.1%). It should be noted, however, that patients with atypical CP were less likely (p<0.001) to receive medications (aspirin 90.4% vs. 96.2%; beta-blockers 66.9% vs. 78.9%) and invasive procedures (21% vs. 47.6%) than patients with typical CP. Conclusions: ACS without typical CP is not a rare experience and it is associated many co-morbidity and poor outcome, both in women and men. Strategies to avoid underestimation of atypical symptoms represent potential opportunities for improving the outcome of these patients

Effect of pre-procedural antiplatelet and anticoagulant therapy on myocardial no-reflow following percutaneus coronary intervention

Background: No-reflow occurring during percutaneus coronary intervention (PCI) has been associated with poor in-hospital outcomes. Purpose: The objectives of this study were to evaluate the incidence of no-reflow as independent predictor of adverse events and to assess whether baseline preprocedural treatment options may affect clinical outcomes. Methods: Data were derived from the International Survey of Acute Coronary Syndromes in Transitional Countries (NCT01218776) registry, a prospective survey of patients presenting with ACS over a 5-year period (January 2010 to January 2015). We prospectively collected data from 5997 patients undergoing PCI, identifying those with no-reflow, and analyzed their treatments and clinical outcomes. No-reflow was defined as post-PCI TIMI flow grade 0–1, in the absence of post-procedural significant (≥25%) residual stenosis, abrupt vessel closure, dissection, perforation, thrombus of the original target lesion, or epicardial spasm. The outcome measure was in-hospital mortality. Results: No-reflow was identified in 128 of 5997 patients who have undergone PCI (2.1%). On multivariate analysis, patients with no-reflow were more likely to be older (≥75 years; OR: 2.78; 95% CI: 1.15–6.71) and to have ST-elevation myocardial infarction (OR: 3.67; 95% CI: 1.57–8.56). No-reflow was highly predictive of in-hospital mortality (17.2% vs. 4.2%, P<0.001) and remained a significant independent predictor of death after adjustment for demographic and clinical variables (OR: 4.78; 95% CI: 2.7- 8.3). Multivariable regression analysis was also performed to identify independent relationship between pre-procedural treatment regimens and no-reflow phenomenon. A 600 mg loading dose of clopidogrel, showed a strong inverse predictive value in terms of post-PCI TIMI flow and no-reflow phenomenon (OR: 0.58; 95% CI: 0.35–0.95). Similarly, unfractioned heparin was associated with a reduction in the likehood of no-reflow (OR: 0.62; 95% CI: 0.41–0.94). Aspirin, enoxaparin, 300 mg loading dose of clopidogrel, did not significantly impact the occurrence of the no-reflow. Conclusions: No-reflow is a strong independent predictor of in-hospital mortality. Pre-procedural administration of 600 mg loading dose of clopidogrel and/or unfractioned heparin is associated with reduced incidence of no-reflo

In-hospital outcome in octogenarians with acute coronary syndrome undergoing invasive coronary procedures

Background: Limited data are available in octogenarian patients, and most of these studies excluded older patients with significant co morbid conditions. This is an observational study of octogenarians admitted for acute coronary syndrome (ACS). Purpose: We sought to investigate clinical characteristics, treatment and outcome of octogenarian patients during hospital stay for ACS in transitional country. Methods: Data were collected in the ISACS-TC registry (ClinicalTrials.gov,NCT01218776) from October 2010 to February 2015: there were 992 patients ≥80 years old, consecutive admitted with a diagnosis of ACS at 58 hospitals in 11 Eastern European countries. Patients who had undergone fibrinolysis and coronary artery bypass grafting (CABG), were also excluded. In-hospital mortality was the primary end-point. Results: Octogenarian patients represent 7.5% of ISACS-CT population. Among these, 56.7% were admitted with a diagnosis of ST segment elevation myocardial infarction (STEMI). The mean age of the study population was 83.5±3.5 years and 51.6% of the patients were women. Female, less frequently than male, had history of myocardial infarction, peripheral artery disease (PAD), prior CABG and chronic kidney disease. They were less likely to have smoking and former smoking status. There was no difference in the rates of death between male (18.5%) and female (19.2%) patients. Octogenarian patients undergoing invasive coronary procedures had significantly lower rate of death (12.5% vs 22.2 P<0.001). In multivariable regression analysis, cardiovascular death in the octogenarians was associated (p<0.05) with age ≥85 years (odds ratio [OR] 1.82), prior PAD (OR: 4.92) and Killip class ≥2 (OR 4.41). Invasive coronary procedures was an independent significant protective factor on hospital mortality (OR 0.43). Conclusions: Octogenarian ACS patients have a high mortality rate which can be reduced by invasive coronary procedures. Age is relevant in the prognosis of ACS, but its importance should be considered not secondary to other clinical factors