Comparative long-term effects of coronary artery bypass graft surgery and percutaneous transluminal coronary angioplasty on regional coronary flow reserve.

peer reviewedTo evaluate the relative long-term improvement in coronary artery hemodynamics after revascularization by coronary artery bypass graft surgery (CABG) or percutaneous transluminal coronary angioplasty (PTCA), regional coronary flow reserve (CFR) was measured, by digital computer analysis of 35 mm cine film, in 50 men undergoing cardiac catheterization. CFR (mean +/- SEM) in 12 atherosclerotic arteries before revascularization was 1.02 +/- 0.05. Mean CFR in 29 normal arteries of men with normal coronary arteriograms was significantly higher (2.59 +/- 0.11) than that in 16 atherosclerotic arteries of patients revascularized by CABG (2.02 +/- 0.17, p less than .01) or in 14 atherosclerotic arteries of those revascularized by PTCA (1.97 +/- 0.12, p less than .01). No difference in CFR between the CABG and PTCA groups was found and variables known to influence CFR were similar between groups. Equivalent and significant long-term improvement in coronary artery hemodynamics is provided by CABG or PTCA. We postulate that the difference in CFR in the men with normal arteries and those who underwent revascularization was related to the effects of the general atherosclerotic process, which remain despite successful treatment by these techniques

Quantitative assessment of global and regional left ventricular function with low-contrast dose digital subtraction ventriculography.

Few studies have compared the use of low-contrast dose digital subtraction ventriculography with conventional ventriculography for quantitative assessment of both global and regional left ventricular function. Accordingly, 34 patients underwent conventional ventriculography using 36 ml of ionic contrast material and digital ventriculography (mask-mode) using 10 ml of contrast diluted in 10 ml of saline and injected over two seconds. Data from two patients were excluded because of ectopy during cineventriculography and from one because of ectopy during both studies. End-diastolic and end-systolic volumes were calculated from both studies by an area-length method and used to calculate ejection fractions. Regional wall motion was quantitated by the centerline method. Results of linear regression analysis demonstrated high correlations for all parameters (end-diastolic volume, r = 0.85; end-systolic volume, r = 0.93; ejection fraction, r = 0.92; quantitative regional wall motion, r = 0.90). Thus, low-contrast dose digital subtraction ventriculography provides an accurate assessment of both global and regional ventricular function and minimizes the required dose and inherent risks of contrast media

Long-term fluvastatin reduces the hazardous effect of renal impairment on four-year atherosclerotic outcomes (a LIPS substudy)

peer reviewedMild renal impairment is an important risk factor for late cardiovascular complications. This substudy of the Lescol Intervention Prevention Study (LIPS) assessed the effect of fluvastatin on outcome of patients who had renal dysfunction and those who did not. Complete data for creatinine clearance calculation. (Cockcroft=Gault formula) were available for 1,558 patients (92.9% of the LIPS population). Patients were randomized to fluvastatin or placebo after successful completion of a first percutaneous coronary intervention. Follow-up time was, 3 to 4 years. The effect of baseline creatinine clearance on coronary atherosclerotic events (cardiac death, non-fatal myocardial infarction, and coronary reinterventions not related to restenosis) was evaluated. Baseline creatinine clearance (logarithmic transformation) was inversely associated with an incidence of adverse events among patients who received, placebo. (hazard ratio 0.99, 95% confidence interval 0.982 to 0.998, p = 0.01). However, no association was noted between creatinine clearance and the incidence of adverse events among patients who received fluvastatin (hazard ratio 1.0, 95% confidence interval 0.99 to 1.0, p = 0.63). No further deterioration in creatinine clearance was observed during follow-up; regardless of baseline renal function or allocated treatment. Occurrence of adverse events was not related to changes in renal function during follow-up. Fluvastatin therapy markedly decreased the risk of coronary atherosclerotic events after percutaneous intervention in: patients who had lower values of creatinine clearance at baseline: The benefit of fluvastatin was unrelated to any effect on renal function. (C) 2005 by Excerpta Medica Inc

Direct stenting with the Bx VELOCITY balloon-expandable stent mounted on the Raptor rapid exchange delivery system versus predilatation in a European randomized Trial: the VELVET trial.

Abstract AIMS: This study examined the six-month angiographic results of direct coronary stenting, and compared the nine-month safety, efficacy and cost of this strategy versus stenting after balloon predilatation. METHODS: In phase I of VELVET, 122 patients (mean age = 62.3 +/- 10.1 years, 77% male, 11% with diabetes) with angina pectoris or myocardial ischemia resulting from a single de novo 51% to 95% coronary stenosis underwent direct stenting. The endpoints of phase I included angiographic findings and rates of major adverse cardiac events up to six months of follow-up. In phase II, 401 patients (mean age = 61.3 +/- 10.8 years, 79% male, 16% with diabetes) with angina pectoris or documented myocardial ischemia resulting from single or multiple, de novo or restenotic, coronary lesions were randomized between direc

Treatment of aortic stenosis with a self-expanding transcatheter valve: the International Multi-centre ADVANCE Study

Aim Transcatheter aortic valve implantation has become an alternative to surgery in higher risk patients with symptomatic aortic stenosis. The aim of the ADVANCE study was to evaluate outcomes following implantation of a self-expanding transcatheter aortic valve system in a fully monitored, multi-centre ‘real-world' patient population in highly experienced centres. Methods and results Patients with severe aortic stenosis at a higher surgical risk in whom implantation of the CoreValve System was decided by the Heart Team were included. Endpoints were a composite of major adverse cardiovascular and cerebrovascular events (MACCE; all-cause mortality, myocardial infarction, stroke, or reintervention) and mortality at 30 days and 1 year. Endpoint-related events were independently adjudicated based on Valve Academic Research Consortium definitions. A total of 1015 patients [mean logistic EuroSCORE 19.4 ± 12.3% [median (Q1,Q3), 16.0% (10.3, 25.3%)], age 81 ± 6 years] were enrolled. Implantation of the CoreValve System led to a significant improvement in haemodynamics and an increase in the effective aortic valve orifice area. At 30 days, the MACCE rate was 8.0% (95% CI: 6.3-9.7%), all-cause mortality was 4.5% (3.2-5.8%), cardiovascular mortality was 3.4% (2.3-4.6%), and the rate of stroke was 3.0% (2.0-4.1%). The life-threatening or disabling bleeding rate was 4.0% (2.8-6.3%). The 12-month rates of MACCE, all-cause mortality, cardiovascular mortality, and stroke were 21.2% (18.4-24.1%), 17.9% (15.2-20.5%), 11.7% (9.4-14.1%), and 4.5% (2.9-6.1%), respectively. The 12-month rates of all-cause mortality were 11.1, 16.5, and 23.6% among patients with a logistic EuroSCORE ≤10%, EuroSCORE 10-20%, and EuroSCORE >20% (P< 0.05), respectively. Conclusion The ADVANCE study demonstrates the safety and effectiveness of the CoreValve System with low mortality and stroke rates in higher risk real-world patients with severe aortic stenosi

Risk factors and a predictive model for under-five mortality in Nigeria: evidence from Nigeria demographic and health survey

<p>Abstract</p> <p>Background</p> <p>Under-5 mortality is a major public health challenge in developing countries. It is essential to identify determinants of under-five mortality (U5M) childhood mortality because these will assist in formulating appropriate health programmes and policies in order to meet the United Nations MDG goal. The objective of this study was to develop a predictive model and identify maternal, child, family and other risk factors associated U5M in Nigeria.</p> <p>Methods</p> <p>Population-based cross-sectional study which explored 2008 demographic and health survey of Nigeria (NDHS) with multivariable logistic regression. Likelihood Ratio Test, Hosmer-Lemeshow Goodness-of-Fit and Variance Inflation Factor were used to check the fit of the model and the predictive power of the model was assessed with Receiver Operating Curve (ROC curve).</p> <p>Results</p> <p>This study yielded an excellent predictive model which revealed that the likelihood of U5M among the children of mothers that had their first marriage at age 20-24 years and ≥ 25 years declined by 20% and 30% respectively compared to children of those that married before the age of 15 years. Also, the following factors reduced odds of U5M: health seeking behaviour, breastfeeding children for > 18 months, use of contraception, small family size, having one wife, low birth order, normal birth weight, child spacing, living in urban areas, and good sanitation.</p> <p>Conclusions</p> <p>This study has revealed that maternal, child, family and other factors were important risk factors of U5M in Nigeria. This study has identified important risk factors that will assist in formulating policies that will improve child survival.</p

How do 66 European institutional review boards approve one protocol for an international prospective observational study on traumatic brain injury? Experiences from the CENTER-TBI study

Background The European Union (EU) aims to optimize patient protection and efficiency of health-care research by harmonizing procedures across Member States. Nonetheless, further improvements are required to increase multicenter research efficiency. We investigated IRB procedures in a large prospective European multicenter study on traumatic brain injury (TBI), aiming to inform and stimulate initiatives to improve efficiency. Methods We reviewed relevant documents regarding IRB submission and IRB approval from European neurotrauma centers participating in the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI). Documents included detailed information on IRB procedures and the duration from IRB submission until approval(s). They were translated and analyzed to determine the level of harmonization of IRB procedures within Europe. Results From 18 countries, 66 centers provided the requested documents. The primary IRB review was conducted centrally (N = 11, 61%) or locally (N = 7, 39%) and primary IRB approval was obtained after one (N = 8, 44%), two (N = 6, 33%) or three (N = 4, 23%) review rounds with a median duration of respectively 50 and 98 days until primary IRB approval. Additional IRB approval was required in 55% of countries and could increase duration to 535 days. Total duration from submission until required IRB approval was obtained was 114 days (IQR 75-224) and appeared to be shorter after submission to local IRBs compared to central IRBs (50 vs. 138 days, p = 0.0074). Conclusion We found variation in IRB procedures between and within European countries. There were differences in submission and approval requirements, number of review rounds and total duration. Research collaborations could benefit from the implementation of more uniform legislation and regulation while acknowledging local cultural habits and moral values between countries.Peer reviewe

Machine learning algorithms performed no better than regression models for prognostication in traumatic brain injury

Objective: We aimed to explore the added value of common machine learning (ML) algorithms for prediction of outcome for moderate and severe traumatic brain injury. Study Design and Setting: We performed logistic regression (LR), lasso regression, and ridge regression with key baseline predictors in the IMPACT-II database (15 studies, n = 11,022). ML algorithms included support vector machines, random forests, gradient boosting machines, and artificial neural networks and were trained using the same predictors. To assess generalizability of predictions, we performed internal, internal-external, and external validation on the recent CENTER-TBI study (patients with Glasgow Coma Scale <13, n = 1,554). Both calibration (calibration slope/intercept) and discrimination (area under the curve) was quantified. Results: In the IMPACT-II database, 3,332/11,022 (30%) died and 5,233(48%) had unfavorable outcome (Glasgow Outcome Scale less than 4). In the CENTER-TBI study, 348/1,554(29%) died and 651(54%) had unfavorable outcome. Discrimination and calibration varied widely between the studies and less so between the studied algorithms. The mean area under the curve was 0.82 for mortality and 0.77 for unfavorable outcomes in the CENTER-TBI study. Conclusion: ML algorithms may not outperform traditional regression approaches in a low-dimensional setting for outcome prediction after moderate or severe traumatic brain injury. Similar to regression-based prediction models, ML algorithms should be rigorously validated to ensure applicability to new populations

Variation in Structure and Process of Care in Traumatic Brain Injury: Provider Profiles of European Neurotrauma Centers Participating in the CENTER-TBI Study.

INTRODUCTION: The strength of evidence underpinning care and treatment recommendations in traumatic brain injury (TBI) is low. Comparative effectiveness research (CER) has been proposed as a framework to provide evidence for optimal care for TBI patients. The first step in CER is to map the existing variation. The aim of current study is to quantify variation in general structural and process characteristics among centers participating in the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study. METHODS: We designed a set of 11 provider profiling questionnaires with 321 questions about various aspects of TBI care, chosen based on literature and expert opinion. After pilot testing, questionnaires were disseminated to 71 centers from 20 countries participating in the CENTER-TBI study. Reliability of questionnaires was estimated by calculating a concordance rate among 5% duplicate questions. RESULTS: All 71 centers completed the questionnaires. Median concordance rate among duplicate questions was 0.85. The majority of centers were academic hospitals (n = 65, 92%), designated as a level I trauma center (n = 48, 68%) and situated in an urban location (n = 70, 99%). The availability of facilities for neuro-trauma care varied across centers; e.g. 40 (57%) had a dedicated neuro-intensive care unit (ICU), 36 (51%) had an in-hospital rehabilitation unit and the organization of the ICU was closed in 64% (n = 45) of the centers. In addition, we found wide variation in processes of care, such as the ICU admission policy and intracranial pressure monitoring policy among centers. CONCLUSION: Even among high-volume, specialized neurotrauma centers there is substantial variation in structures and processes of TBI care. This variation provides an opportunity to study effectiveness of specific aspects of TBI care and to identify best practices with CER approaches