Long-term mortality prediction after operations for type A ascending aortic dissection

<p>Abstract</p> <p>Background</p> <p>There are few long-term mortality prediction studies after acute aortic dissection (AAD) Type A and none were performed using new models such as neural networks (NN) or support vector machines (SVM) which may show a higher discriminatory potency than standard multivariable models.</p> <p>Methods</p> <p>We used 32 risk factors identified by Literature search and previously assessed in short-term outcome investigations. Models were trained (50%) and validated (50%) on 2 random samples from a consecutive 235-patient cohort. NN were run only on patients with complete data for all included variables (N = 211); SVM on the overall group. Discrimination was assessed by receiver operating characteristic area under the curve (AUC) and Gini's coefficients along with classification performance.</p> <p>Results</p> <p>There were 84 deaths (36%) occurring at 564 ± 48 days (95%CI from 470 to 658 days). Patients with complete variables had a slightly lower death rate (60 of 211, 28%). NN classified 44 of 60 (73%) dead patients and 147 of 151 (97%) long-term survivors using 5 covariates: immediate post-operative chronic renal failure, circulatory arrest time, the type of surgery on ascending aorta plus hemi-arch, extracorporeal circulation time and the presence of Marfan habitus. Global accuracies of training and validation NN were excellent with AUC respectively 0.871 and 0.870 but classification errors were high among patients who died. Training SVM, using a larger number of covariates, showed no false negative or false positive cases among 118 randomly selected patients (error = 0%, AUC 1.0) whereas validation SVM, among 117 patients, provided 5 false negative and 11 false positive cases (error = 22%, AUC 0.821, p < 0.01 versus NN results). An html file was produced to adopt and manipulate the selected parameters for practical predictive purposes.</p> <p>Conclusions</p> <p>Both NN and SVM accurately selected a few operative and immediate post-operative factors and the Marfan habitus as long-term mortality predictors in AAD Type A. Although these factors were not new per se, their combination may be used in practice to index death risk post-operatively with good accuracy.</p

Artificial Neural Networks Versus Multiple Logistic Regression to Predict 30-Day Mortality After Operations For Type A Ascending Aortic Dissection§

There are few comparative reports on the overall accuracy of neural networks (NN), assessed only versus multiple logistic regression (LR), to predict events in cardiovascular surgery studies and none has been performed among acute aortic dissection (AAD) Type A patients. OBJECTIVES: We aimed at investigating the predictive potential of 30-day mortality by a large series of risk factors in AAD Type A patients comparing the overall performance of NN versus LR. METHODS: We investigated 121 plus 87 AAD Type A patients consecutively operated during 7 years in two Centres. Forced and stepwise NN and LR solutions were obtained and compared, using receiver operating characteristic area under the curve (AUC) and their 95% confidence intervals (CI) and Gini's coefficients. Both NN and LR models were re-applied to data from the second Centre to adhere to a methodological imperative with NN. RESULTS: Forced LR solutions provided AUC 87.9+/-4.1% (CI: 80.7 to 93.2%) and 85.7+/-5.2% (CI: 78.5 to 91.1%) in the first and second Centre, respectively. Stepwise NN solution of the first Centre had AUC 90.5+/-3.7% (CI: 83.8 to 95.1%). The Gini's coefficients for LR and NN stepwise solutions of the first Centre were 0.712 and 0.816, respectively. When the LR and NN stepwise solutions were re-applied to the second Centre data, Gini's coefficients were, respectively, 0.761 and 0.850. Few predictors were selected in common by LR and NN models: the presence of pre-operative shock, intubation and neurological symptoms, immediate post-operative presence of dialysis in continuous and the quantity of post-operative bleeding in the first 24 h. The length of extracorporeal circulation, post-operative chronic renal failure and the year of surgery were specifically detected by NN. CONCLUSIONS: Different from the International Registry of AAD, operative and immediate post-operative factors were seen as potential predictors of short-term mortality. We report a higher overall predictive accuracy with NN than with LR. However, the list of potential risk factors to predict 30-day mortality after AAD Type A by NN model is not enlarged significantly

Quality of life and treatment satisfaction in adults with Type 1 diabetes: A comparison between continuous subcutaneous insulin infusion and multiple daily injections

Aims: The aim of this case-control study was to compare quality of life (QoL) and treatment satisfaction in adults with Type 1 diabetes (T1DM) treated with either continuous subcutaneous insulin infusion (CSII) or multiple daily injections (MDI). Methods: Consecutive patients aged between 18 and 55 years, and attending diabetes clinics for a routine visit, completed the Diabetes-Specific Quality-of-Life Scale (DSQOLS), the Diabetes Treatment Satisfaction Questionnaire (DTSQ) and the SF-36 Health Survey (SF-36). Case (CSII) and control subjects (MDI) were recruited in a 1 : 2 ratio. Results: Overall, 1341 individuals were enrolled by 62 diabetes clinics; 481 were cases and 860 control subjects. Cases had a longer diabetes duration and were more likely to have eye and renal complications. Age, school education, occupation and HbA1c were similar. Of control subjects, 90% followed glargine-based MDI regimens and 10% used NPH-based MDI regimens. On multivariate analysis, after adjusting for socioeconomic and clinical characteristics, scores in the following areas of the DSQOLS were higher in cases than control subjects: diet restrictions (β = 5.96; P &lt; 0.0001), daily hassles (β = 3.57; P = 0.01) and fears about hypoglycaemia (β = 3.88; P = 0.006). Treatment with CSII was also associated with a markedly higher DTSQ score (β = 4.13; P &lt; 0.0001) compared with MDI. Results were similar when CSII was compared separately with glargine- or NPH-based MDI regimens. Conclusions: This large, non-randomized, case-control study suggests quality of life gains deriving from greater lifestyle flexibility, less fear of hypoglycaemia, and higher treatment satisfaction, when CSII is compared with either glargine-based or NPH-based MDI regimens. © 2008 The Authors

Association of kidney disease measures with risk of renal function worsening in patients with type 1 diabetes

Background: Albuminuria has been classically considered a marker of kidney damage progression in diabetic patients and it is routinely assessed to monitor kidney function. However, the role of a mild GFR reduction on the development of stage 653 CKD has been less explored in type 1 diabetes mellitus (T1DM) patients. Aim of the present study was to evaluate the prognostic role of kidney disease measures, namely albuminuria and reduced GFR, on the development of stage 653 CKD in a large cohort of patients affected by T1DM. Methods: A total of 4284 patients affected by T1DM followed-up at 76 diabetes centers participating to the Italian Association of Clinical Diabetologists (Associazione Medici Diabetologi, AMD) initiative constitutes the study population. Urinary albumin excretion (ACR) and estimated GFR (eGFR) were retrieved and analyzed. The incidence of stage 653 CKD (eGFR &lt; 60 mL/min/1.73 m2) or eGFR reduction &gt; 30% from baseline was evaluated. Results: The mean estimated GFR was 98 \ub1 17 mL/min/1.73m2 and the proportion of patients with albuminuria was 15.3% (n = 654) at baseline. About 8% (n = 337) of patients developed one of the two renal endpoints during the 4-year follow-up period. Age, albuminuria (micro or macro) and baseline eGFR &lt; 90 ml/min/m2 were independent risk factors for stage 653 CKD and renal function worsening. When compared to patients with eGFR &gt; 90 ml/min/1.73m2 and normoalbuminuria, those with albuminuria at baseline had a 1.69 greater risk of reaching stage 3 CKD, while patients with mild eGFR reduction (i.e. eGFR between 90 and 60 mL/min/1.73 m2) show a 3.81 greater risk that rose to 8.24 for those patients with albuminuria and mild eGFR reduction at baseline. Conclusions: Albuminuria and eGFR reduction represent independent risk factors for incident stage 653 CKD in T1DM patients. The simultaneous occurrence of reduced eGFR and albuminuria have a synergistic effect on renal function worsening

Extensive use of peripheral angioplasty, particularly infrapopliteal, in the treatment of ischaemic diabetic foot ulcers : clinical results of a multicentric study of 221 consecutive diabetic subjects

OBJECTIVE: To evaluate the feasibility, technical effectiveness and limb salvage potential of percutaneous transluminal angioplasty (PTA), particularly infrapopliteal, in diabetic subjects with ischaemic foot ulcer. DESIGN: Intervention study with PTA in consecutive series. SETTING: Six Diabetology Foot Centres and one Cardiovascular Catheterization Laboratory in Italy. SUBJECTS: Two hundred and twenty-one consecutive diabetic subjects hospitalized for ischaemic foot ulcer. INTERVENTION: Peripheral arterial occlusive disease (PAOD) was investigated by means of foot pulses assessment, ankle-brachial-index (ABI), transcutaneous oxygen tension (TcPO2) and duplex scanning. If non-invasive parameters suggested PAOD, angiography was performed and a PTA was carried out during the same session. MAIN OUTCOME MEASURES: PTA feasibility, improvement of ABI and TcPO2, limb salvage rate, clinical recurrence. RESULTS: On angiography, two patients had stenoses which were 50%, even when longer than 10 cm and/or multiple/calcified. In 11 patients (5.8%) PTA was performed in the proximal axis exclusively, in 81 (42.4%) patients in the infrapopliteal axis exclusively and in 99 (51.8%) in both the femoropopliteal and infrapopliteal axis. Both ABI and TcPO2 improved significantly after PTA (P < 0.0001). Clinical recurrence occurred in 14 subjects: 10 of whom underwent a second successful PTA. Of the 191 patients who underwent PTA, 10 (5.2%) underwent an above-the-ankle amputation. CONCLUSIONS: PTA, including infrapopliteal, is feasible in most diabetic subjects with ischaemic foot ulcer and is effective for foot revascularization. Clinical recurrence was infrequent and the procedure could successfully be repeated in most cases. In subjects treated successfully with PTA the above-the-ankle amputation rate was low. PTA should be considered as the revascularization treatment of first choice in all diabetic subjects with foot ulcer and PAOD

Distribuzione urbana delle merci tramite ferrovia regionale: un’applicazione test nella penisola Sorrentina

In questa nota è affrontato il problema della distribuzione delle merci utilizzando per l’accesso all’area metropolitana le presenti infrastrutture ferroviarie. È descritta una metodologia per l’analisi della fattibilità tecnico-economica del sistema di progetto che prevede la messa a punto di un sistema di modelli per la stima della domanda merci di prodotti finali; è sinteticamente descritta l’applicazione alla penisola Sorrentina

Metropolitan freight distribution by railways: a methodology to support the feasibility analysis

This paper presents the obtained results of a methodology implemented for the feasibility analysis, both technical and economic, of freight distribution systems in urban and/or metropolitan areas using railways, which includes a system of urban freight demand models. The scope of this research is to assess a competitive rail transport option with respect road truck transport for some specific types of goods. The first part of the paper presents a state-of-the-art focusing on international and national experiences of the use of railways infrastructures for urban freight distribution, and describes the general framework of freight demand models for urban and metropolitan areas; the latter proposes a modelling system to estimate the freight demand to be used within the methodology for the technical and economic feasibility analysis of freight distribution systems using railways infrastructures. Finally, results of an application to a real test case are reported. They refer to the study case of the Sorrentina peninsula, which is one of the most famous tourist areas near Naples (centre-Italy), well-known for its low accessibility by roads

Metropolitan freight distribution by railways: a methodology to support the feasibility analysis

This paper presents the obtained results of a methodology implemented for the feasibility analysis, both technical and economic, of freight distribution systems in urban and/or metropolitan areas using railways, which includes a system of urban freight demand models. The scope of this research is to assess a competitive rail transport option with respect road truck transport for some specific types of goods. The first part of the paper presents a state-of-the-art focusing on international and national experiences of the use of railways infrastructures for urban freight distribution, and describes the general framework of freight demand models for urban and metropolitan areas; the latter proposes a modelling system to estimate the freight demand to be used within the methodology for the technical and economic feasibility analysis of freight distribution systems using railways infrastructures. Finally, results of an application to a real test case are reported. They refer to the study case of the Sorrentina peninsula, which is one of the most famous tourist areas near Naples (centre-Italy), well-known for its low accessibility by roads