Unraveling pedestrian mobility on a road network using ICTs data during great tourist events

Tourist flows in historical cities are continuously growing in a globalized world and adequate governance processes, politics and tools are necessary in order to reduce impacts on the urban livability and to guarantee the preservation of cultural heritage. The ICTs offer the possibility of collecting large amount of data that can point out and quantify some statistical and dynamic properties of human mobility emerging from the individual behavior and referring to a whole road network. In this paper we analyze a new dataset that has been collected by the Italian mobile phone company TIM, which contains the GPS positions of a relevant sample of mobile devices when they actively connected to the cell phone network. Our aim is to propose innovative tools allowing to study properties of pedestrian mobility on the whole road network. Venice is a paradigmatic example for the impact of tourist flows on the resident life quality and on the preservation of cultural heritage. The GPS data provide anonymized georeferenced information on the displacements of the devices. After a filtering procedure, we develop specific algorithms able to reconstruct the daily mobility paths on the whole Venice road network. The statistical analysis of the mobility paths suggests the existence of a travel time budget for the mobility and points out the role of the rest times in the empirical relation between the mobility time and the corresponding path length. We succeed to highlight two connected mobility subnetworks extracted from the whole road network, that are able to explain the majority of the observed mobility. Our approach shows the existence of characteristic mobility paths in Venice for the tourists and for the residents. Moreover the data analysis highlights the different mobility features of the considered case studies and it allows to detect the mobility paths associated to different points of interest. Finally we have disaggregated the Italian and foreigner categories to study their different mobility behaviors

Proceedings of the Fifth Italian Conference on Computational Linguistics CLiC-it 2018

On behalf of the Program Committee, a very warm welcome to the Fifth Italian Conference on Computational Linguistics (CLiC-­‐it 2018). This edition of the conference is held in Torino. The conference is locally organised by the University of Torino and hosted into its prestigious main lecture hall “Cavallerizza Reale”. The CLiC-­‐it conference series is an initiative of the Italian Association for Computational Linguistics (AILC) which, after five years of activity, has clearly established itself as the premier national forum for research and development in the fields of Computational Linguistics and Natural Language Processing, where leading researchers and practitioners from academia and industry meet to share their research results, experiences, and challenges

Long-term variations of FFR and iFR after transcatheter aortic valve implantation

Long-term variations of fractional flow reserve (FFR) and instantaneous wave-free-ratio (iFR) after transcatheter aortic valve implantation (TAVI) have not been previously assessed. A total of 23 coronary lesions in 14 patients with aortic stenosis (AS) underwent physiology assessment at baseline, immediately after TAVI and at 14(7-29) months of follow-up. The angiographic severity of the lesions did not progress at follow-up (54[45-64] vs 54[49-63], p = .53). Overall, FFR (0.87[0.85-0.92] vs 0.88[0.82-0.92], p = .45) and iFR (0.88[0.85-0.96] vs 0.91[0.86-0.97], p = .30) did not change significantly compared with the baseline. FFR decreased in 3(13%) lesions with abnormal baseline value, whereas it remained stable in lesions with FFR > 0.80. Conversely, iFR did not show a systematic trend at long-term after TAVI. However, iFR demonstrated a higher reclassification rate at follow-up compared with FFR (p = .02). In conclusions, in this exploratory study, only minor variations of coronary physiology indices were observed at long-term after TAVI. Nevertheless, caution should be exercised in the interpretation of borderline FFR and iFR values in severe AS

Management of failed stenting of the unprotected left main coronary artery

Percutaneous coronary intervention (PCI) is increasingly accepted as treatment for unprotected left main coronary artery (ULMCA) disease especially in those patients who are unsuitable for cardiac surgery. Treatment of any stent failure is associated with increased complexity and worse clinical outcomes when compared with de novo lesion revascularization. Intracoronary imaging has provided new insight into mechanisms of stent failure and treatment options have developed considerably over the last decade. There is paucity of evidence on the management strategy for stent failure in the specific setting of ULMCA. Treating any left main with PCI requires careful consideration and consequently treatment of failed stents in ULMCA is complex and provides unique challenges. Consequently, we provide an overview of ULMCA stent failure, proposing a tailored algorithm to guide best management and decision in daily clinical practice, with a special focus on intracoronary imaging characterization of causal mechanisms and specific technical and procedural considerations

Real World Performance Evaluation of Transcatheter Aortic Valve Implantation

Background: The aim of this research is to describe the performance over time of transcatheter aortic valve implantations (TAVIs) in a high-volume center with a contemporary, real-world population. Methods: Patients referred for TAVIs at the University Hospital of Verona were prospectively enrolled. By cumulative sum failures analysis (CUSUM), procedural-control curves for standardized combined endpoints-as defined by the Valve Academic Research Consortium-2 (VARC-2)-were calculated and analyzed over time. Acceptable and unacceptable limits were derived from recent studies on TAVI in intermediate and low-risk patients to fit the higher required standards for current indications. Results: A total of 910 patients were included. Baseline risk scores significantly reduced over time. Complete procedural control was obtained after approximately 125 and 190 cases for device success and early safety standardized combined endpoints, respectively. High risk patients (STS >= 8) had poorer outcomes, especially in terms of VARC-2 clinical efficacy, and required a higher case load to maintain in-control and proficient procedures. Clinically relevant single endpoints were all influenced by operator's experience as well. Conclusions: Quality-control analysis for contemporary TAVI interventions based on standardized endpoints suggests the need for relevant operator's experience to achieve and maintain optimal clinical results, especially in higher-risk subjects

Intravascular ultrasound assessment of coronary ostia following valve in valve transcatheter aortic valve implantation

Intravascular ultrasound assessment of coronary ostia following valve in valve transcatheter aortic valve implantatio

Extravalvular Cardiac Damage and Renal Function Following Transcatheter Aortic Valve Implantation for Severe Aortic Stenosis

Background: In this study we sought to determine the differences in incidence of acute kidney injury (AKI) and acute kidney recovery (AKR) among patients undergoing transcatheter aortic valve implantation (TAVI), according to the degree of extravalvular cardiac damage (EVCD).Methods: From the Verona Valvular Heart Disease Registry, 674 symptomatic severe aortic stenosis (AS) patients were selected and retrospectively analysed. Using echocardiographic data, patients were classified based on the degree of EVCD.Results: After dichotomized analysis, patients in EVCD stage 3 or 4 reported a significantly higher rate of AKI (29.5% vs 11.2%; P < 0.001). Using a multivariate analysis model, higher EVCD stage, lower glomerular filtrate rate (GFR) at admission, and amount of contrast used were found to be independent predictors of AKI, whereas stage of cardiac damage and GFR were found to be independent predictors of AKR. For the overall population after multivariate analysis AKI was associated with a higher incidence of 12-month all-cause mortality (hazard ratio, 2.142; 95% confidence interval, 1.082-4.239; P = 0.029) with a significant impact in the advanced cardiac damage stages, but not in the early stages (P for interaction = 0.006). AKR did not reduce adverse clinical outcomes but was associated with improved renal function at 12 months.Conclusions: Increase in EVCD stage was associated with a higher rate of AKI after TAVI. AKI had a negative impact on long-term clinical outcomes but only in patients with advanced cardiac damage. AKR did not reduce adverse clinical outcomes but was associated with improved renal function at 12 months

Contrast-Induced Acute Kidney Injury in Patients Undergoing TAVI Compared With Coronary Interventions

Background Differences in the impact of contrast medium on the development of contrast-induced acute kidney injury (CI-AKI) in patients undergoing transcatheter aortic valve implantation (TAVI) or a coronary angiography/percutaneous coronary intervention (CA/PCI) have not been previously investigated. Methods and Results Patients treated with TAVI or elective CA/PCI were retrospectively analyzed in terms of baseline and procedural characteristics, including preprocedural and postprocedural kidney function. CI-AKI was defined as a relative increase in serum creatinine concentration of at least 0.3 mg/dL within 72 hours of contrast-medium administration compared with baseline. The incidence of CI-AKI in the TAVI versus CA/PCI group was compared. After the exclusion of patients in dialysis and emergency procedures, 977 patients were analyzed; there were 489 patients who had undergone TAVI (50.1%) and 488 patients who had undergone CA/PCI (49.9%). Patients treated by TAVI were older, presenting a higher rate of anemia and chronic kidney disease (P<0.001 for all comparisons). Consistently, they also had a significantly lower glomerular filtration rate and higher serum creatinine concentration (P<0.001 for all). However, the occurrence of CI-AKI was significantly lower in these patients compared with patients treated by a CA/PCI (6.7% versus 14.5%, P<0.001). At multivariate analysis, the TAVI procedure had an independent protective effect on CI-AKI incidence among total population (odds ratio, 0.334; 95% CI, 0.193-0.579; P<0.001). This observation was confirmed after propensity score matching among 360 patients (180 by TAVI and 180 by CA/PCI; P=0.002). Conclusions CI-AKI occurred less frequently in patients undergoing TAVI than in patients undergoing a CA/PCI, despite a worse-risk profile. The impact of contrast administration on kidney function in patients who had undergone TAVI may be better tolerated because of the hemodynamic changes following aortic valve replacement

Short-and-Long-Term Outcomes after Coronary Rotational Atherectomy in Patients Treated with Trans-Catheter Aortic Valve Implantation

Background. Coronary artery disease (CAD) is a common finding among patients undergoing trans-catheter aortic valve implantation (TAVI), who often present severely calcified coronary lesions. Evidence is scarce about the use of rotational atherectomy (RA) in this setting, in particular regarding long-term outcome. Methods. RA was performed on severely calcified coronary lesions concomitant with TAVI in a consecutive series of patients treated between 2010 and 2020. Immediate and long-term clinical outcomes are reported. Results. A concomitant CAD (coronary stenosis visually > 50%) was observed in 402/845 (47.6%) consecutive patients undergoing TAVI at the University Hospital of Verona. Angioplasty was performed in 104 patients (12.3%). Among these, 19 patients (18.3%, 20 coronary arteries), were treated with RA after TAVI: 10 after implantation of a balloon-expandable trans-catheter valve and 9 after a self-expandable valve. All procedures were successful. Hypotension occurred in 3 patients (15.8%), with rapid recovery after the procedure; CI-AKI (contrast-induced acute kidney injury) in 3 patients (15.8%), of which two recovered within discharge. At a median follow-up of 21.5 months (Q1–3: 6–36) event free survival was 83.3%. Only one patient suffered a target vessel failure >2 years after RA. Neither stroke nor peri-procedural infarctions were detected. Conclusions. RA concomitant with TAVI was feasible and safe in patients treated with implantation of either self-expandable, or balloon-expandable trans-catheter aortic valves. Long-term clinical events related to the coronary procedure were extremely infrequent and the survival rate at median follow-up of 21.5 months was 83.3%

Physiological Versus Angiographic Guidance for Myocardial Revascularization in Patients Undergoing Transcatheter Aortic Valve Implantation

Background-Management of coronary artery disease in patients undergoing transcatheter aortic valve implantation is uncertain. Fractional flow reserve (FFR) has never been clinically validated in aortic stenosis. The study aim was to analyze the clinical outcome of FFR-guided revascularization in patients undergoing transcatheter aortic valve implantation.Methods and Results-Patients with severe aortic stenosis and coronary artery disease at coronary angiography were included in this retrospective analysis and divided in 2 groups: angiography guided (122/216; 56.5%) versus FFR-guided revascularization (94/216; 43.5%). Patients were clinically followed up and evaluated for the occurrence of major adverse cardiac and cerebrovascular events at 2-year follow-up. Most lesions in the FFR group resulted negative according to the conventional 0.80 cutoff value (111/142; 78.2%) and were deferred. The FFR-guided group showed a better major adverse cardiac and cerebrovascular event-free survival compared with the angio-guided group (92.6% versus 82.0%; hazard ratio, 0.4; 95% CI, 0.2-1.0; P=0.035). Patients with deferred lesions based on FFR presented better outcome compared with patients who underwent angio-guided percutaneous coronary intervention (91.4% versus 68.1%; hazard ratio, 0.3; 95% CI, 0.1-0.6; P=0.001).Conclusions-FFR guidance was associated with favorable outcome in this observational study in patients undergoing transcatheter aortic valve implantation. Randomized trials are needed to investigate the long-term effects of FFR-guided revascularization against angiographic guidance alone in patients with aortic stenosis