Cardiac rehabilitation versus standard care after aortic aneurysm repair (Aneurysm CaRe): study protocol for a randomised controlled trial.

BACKGROUND: Abdominal and thoracic aortic aneurysms (A/TAA) are an important cause of mortality amongst the older population. Although A/TAA repair can be performed with low peri-operative risk, overall life expectancy remains poor in the years that follow surgery. The majority of deaths are caused by heart attack or stroke, which can both be prevented by cardiac rehabilitation (CR) in patients with clinically-manifest coronary artery disease. A Cochrane review has urged researchers to widen the use of CR to other populations with severe cardiovascular risk, and patients surviving A/TAA repair appear ideal candidates. However, it is unknown whether CR is feasible or acceptable to A/TAA patients, who are a decade older than those currently enrolling in CR. Aneurysm-CaRe is a feasibility randomised controlled trial (RCT) that will address these issues. METHODS AND DESIGN: Aneurysm-CaRe is a pilot RCT of CR versus standard care after A/TAA repair, with the primary objectives of estimating enrolment to a trial of CR after A/TAA repair and estimating compliance with CR amongst patients with A/TAA. Aneurysm-CaRe will randomise 84 patients at two sites. Patients discharged from hospital after elective A/TAA repair will be randomised to standard care or enrolment in their local CR programme with a protocolised approach to medical cardiovascular risk reduction. The primary outcome measures are enrolment in the RCT and compliance with CR. Secondary outcomes will include phenotypic markers of cardiovascular risk and smoking cessation, alongside disease-specific and generic quality-of-life measures. TRIAL REGISTRATION: ISRCTN 65746249 5 June 2014.

Research activity and the association with mortality.

INTRODUCTION: The aims of this study were to describe the key features of acute NHS Trusts with different levels of research activity and to investigate associations between research activity and clinical outcomes. METHODS: National Institute for Health Research (NIHR) Comprehensive Clinical Research Network (CCRN) funding and number of patients recruited to NIHR Clinical Research Network (CRN) portfolio studies for each NHS Trusts were used as markers of research activity. Patient-level data for adult non-elective admissions were extracted from the English Hospital Episode Statistics (2005-10). Risk-adjusted mortality associations between Trust structures, research activity and, clinical outcomes were investigated. RESULTS: Low mortality Trusts received greater levels of funding and recruited more patients adjusted for size of Trust (n = 35, 2,349 £/bed [95% CI 1,855-2,843], 5.9 patients/bed [2.7-9.0]) than Trusts with expected (n = 63, 1,110 £/bed, [864-1,357] p<0.0001, 2.6 patients/bed [1.7-3.5] p<0.0169) or, high (n = 42, 930 £/bed [683-1,177] p = 0.0001, 1.8 patients/bed [1.4-2.1] p<0.0005) mortality rates. The most research active Trusts were those with more doctors, nurses, critical care beds, operating theatres and, made greater use of radiology. Multifactorial analysis demonstrated better survival in the top funding and patient recruitment tertiles (lowest vs. highest (odds ratio & 95% CI: funding 1.050 [1.033-1.068] p<0.0001, recruitment 1.069 [1.052-1.086] p<0.0001), middle vs. highest (funding 1.040 [1.024-1.055] p<0.0001, recruitment 1.085 [1.070-1.100] p<0.0001). CONCLUSIONS: Research active Trusts appear to have key differences in composition than less research active Trusts. Research active Trusts had lower risk-adjusted mortality for acute admissions, which persisted after adjustment for staffing and other structural factors.

Effect of right ventricular pacing lead site on left ventricular function in patients with high-grade atrioventricular block: results of the Protect-Pace study.

AIM: Chronic right ventricle (RV) apical (RVA) pacing is standard treatment for an atrioventricular (AV) block but may be deleterious to left ventricle (LV) systolic function. Previous clinical studies of non-apical pacing have produced conflicting results. The aim of this randomized, prospective, international, multicentre trial was to compare change in LV ejection fraction (LVEF) between right ventricular apical and high septal (RVHS) pacing over a 2-year study period. METHODS AND RESULTS: We randomized 240 patients (age 74 ± 11 years, 67% male) with a high-grade AV block requiring >90% ventricular pacing and preserved baseline LVEF >50%, to receive pacing at the RVA (n = 120) or RVHS (n = 120). At 2 years, LVEF decreased in both the RVA (57 ± 9 to 55 ± 9%, P = 0.047) and the RVHS groups (56 ± 10 to 54 ± 10%, P = 0.0003). However, there was no significant difference in intra-patient change in LVEF between confirmed RVA (n = 85) and RVHS (n = 83) lead position (P = 0.43). There were no significant differences in heart failure hospitalization, mortality, the burden of atrial fibrillation, or plasma brain natriutetic peptide levels between the two groups. A significantly greater time was required to place the lead in the RVHS position (70 ± 25 vs. 56 ± 24 min, P < 0.0001) with longer fluoroscopy times (11 ± 7 vs. 5 ± 4 min, P < 0.0001). CONCLUSION: In patients with a high-grade AV block and preserved LV function requiring a high percentage of ventricular pacing, RVHS pacing does not provide a protective effect on left ventricular function over RVA pacing in the first 2 years. PROTECT-PACE: ClinicalTrials.gov number NCT00461734.

Variations and inter-relationship in outcome from emergency admissions in England: a retrospective analysis of Hospital Episode Statistics from 2005-2010.

BACKGROUND: The quality of care delivered and clinical outcomes of care are of paramount importance. Wide variations in the outcome of emergency care have been suggested, but the scale of variation, and the way in which outcomes are inter-related are poorly defined and are critical to understand how best to improve services. This study quantifies the scale of variation in three outcomes for a contemporary cohort of patients undergoing emergency medical and surgical admissions. The way in which the outcomes of different diagnoses relate to each other is investigated. METHODS: A retrospective study using the English Hospital Episode Statistics 2005-2010 with one-year follow-up for all patients with one of 20 of the commonest and highest-risk emergency medical or surgical conditions. The primary outcome was in-hospital all-cause risk-standardised mortality rate (in-RSMR). Secondary outcomes were 1-year all-cause risk-standardised mortality rate (1 yr-RSMR) and 28-day all-cause emergency readmission rate (RSRR). RESULTS: 2,406,709 adult patients underwent emergency medical or surgical admissions in the groups of interest. Clinically and statistically significant variations in outcome were observed between providers for all three outcomes (p < 0.001). For some diagnoses including heart failure, acute myocardial infarction, stroke and fractured neck of femur, more than 20% of hospitals lay above the upper 95% control limit and were statistical outliers. The risk-standardised outcomes within a given hospital for an individual diagnostic group were significantly associated with the aggregated outcome of the other clinical groups. CONCLUSIONS: Hospital-level risk-standardised outcomes for emergency admissions across a range of specialties vary considerably and cross traditional speciality boundaries. This suggests that global institutional infra-structure and processes of care influence outcomes. The implications are far reaching, both in terms of investigating performance at individual hospitals and in understanding how hospitals can learn from the best performers to improve outcomes.

Mortality from ruptured abdominal aortic aneurysms: clinical lessons from a comparison of outcomes in England and the USA.

BACKGROUND: The outcome of patients with ruptured abdominal aortic aneurysm (rAAA) varies by country. Study of practice differences might allow the formulation of pathways to improve care. METHODS: We compared data from the Hospital Episode Statistics for England and the Nationwide Inpatient Sample for the USA for patients admitted to hospital with rAAA from 2005 to 2010. Primary outcomes were in-hospital mortality, mortality after intervention, and decision to follow non-corrective treatment. In-hospital mortality and the rate of non-corrective treatment were analysed by binary logistic regression for each health-care system, after adjustment for age, sex, year, and Charlson comorbidity index. FINDINGS: The study included 11,799 patients with rAAA in England and 23,838 patients with rAAA in the USA. In-hospital mortality was lower in the USA than in England (53·05% [95% CI 51·26-54·85] vs 65·90%; p<0·0001). Intervention (open or endovascular repair) was offered to a greater proportion of cases in the USA than in England (19,174 [80·43%] vs 6897 [58·45%]; p<0·0001) and endovascular repair was more common in the USA than in England (4003 [20·88%] vs 589 [8·54%]; p<0·0001). Postintervention mortality was similar in both countries (41·77% for England and 41·65% for USA). These observations persisted in age-matched and sex-matched comparisons. In both countries, reduced mortality was associated with increased use of endovascular repair, increased hospital caseload (volume) for rAAA, high hospital bed capacity, hospitals with teaching status, and admission on a weekday. INTERPRETATION: In-hospital survival from rAAA, intervention rates, and uptake of endovascular repair are lower in England than in the USA. In England and the USA, the lowest mortality for rAAA was seen in teaching hospitals with larger bed capacities and doing a greater proportion of cases with endovascular repair. These common factors suggest strategies for improving outcomes for patients with rAAA. FUNDING: None.

Elective open suprarenal aneurysm repair in England from 2000 to 2010 an observational study of hospital episode statistics.

BACKGROUND: Open surgery is widely used as a benchmark for the results of fenestrated endovascular repair of complex abdominal aortic aneurysms (AAA). However, the existing evidence stems from single-centre experiences, and may not be reproducible in wider practice. National outcomes provide valuable information regarding the safety of suprarenal aneurysm repair. METHODS: Demographic and clinical data were extracted from English Hospital Episodes Statistics for patients undergoing elective suprarenal aneurysm repair from 1 April 2000 to 31 March 2010. Thirty-day mortality and five-year survival were analysed by logistic regression and Cox proportional hazards modeling. RESULTS: 793 patients underwent surgery with 14% overall 30-day mortality, which did not improve over the study period. Independent predictors of 30-day mortality included age, renal disease and previous myocardial infarction. 5-year survival was independently reduced by age, renal disease, liver disease, chronic pulmonary disease, and known metastatic solid tumour. There was significant regional variation in both 30-day mortality and 5-year survival after risk-adjustment. Regional differences in outcome were eliminated in a sensitivity analysis for perioperative outcome, conducted by restricting analysis to survivors of the first 30 days after surgery. CONCLUSIONS: Elective suprarenal aneurysm repair was associated with considerable mortality and significant regional variation across England. These data provide a benchmark to assess the efficacy of complex endovascular repair of supra-renal aneurysms, though cautious interpretation is required due to the lack of information regarding aneurysm morphology. More detailed study is required, ideally through the mandatory submission of data to a national registry of suprarenal aneurysm repair.

Studies using English administrative data (Hospital Episode Statistics) to assess health-care outcomes--systematic review and recommendations for reporting.

BACKGROUND: Studies using English administrative data from the Hospital Episode Statistics (HES) are increasingly used for the assessment of health-care quality. This study aims to catalogue the published body of studies using HES data to assess health-care outcomes, to assess their methodological qualities and to determine if reporting recommendations can be formulated. METHODS: Systematic searches of the EMBASE, Medline and Cochrane databases were performed using defined search terms. Included studies were those that described the use of HES data extracts to assess health-care outcomes. RESULTS: A total of 148 studies were included. The majority of published studies were on surgical specialties (60.8%), and the most common analytic theme was of inequalities and variations in treatment or outcome (27%). The volume of published studies has increased with time (r = 0.82, P < 0.0001), as has the length of study period (r = 0.76, P < 0.001) and the number of outcomes assessed per study (r = 0.72, P = 0.0023). Age (80%) and gender (57.4%) were the most commonly used factors in risk adjustment, and regression modelling was used most commonly (65.2%) to adjust for confounders. Generic methodologic data were better reported than those specific to HES data extraction. For the majority of parameters, there were no improvements with time. CONCLUSIONS: Studies published using HES data to report health-care outcomes have increased in volume, scope and complexity with time. However, persisting deficiencies related to both generic and context-specific reporting have been identified. Recommendations have been made to improve these aspects as it is likely that the role of these studies in assessing health care, benchmarking practice and planning service delivery will continue to increase.

Epidemiological study of provision of cholecystectomy in England from 2000 to 2009: retrospective analysis of Hospital Episode Statistics.

BACKGROUND: The aim of this study was to report the trends in provision of cholecystectomy in the National Health System in England over the 9 year period from 2000 to 2009 and to determine the major risk factors associated with subsequent poor outcome. METHODS: The Hospital Episode Statistics database was interrogated to identify all cholecystectomy procedures for biliary stone disease in adult patients (>16 years). Multivariate regression analyses were used to identify independent predictors of in-patient death, 1 year death, conversion to open, major bile duct injury (BDI) requiring operative repair, and length of stay. RESULTS: A total of 418,214 cholecystectomy procedures for biliary stone disease were identified. Laparoscopic surgery was used in 348,311 (83.3%) cases and increased by 14.6% over the study period. The in-patient mortality rate (0.2%), 1 year mortality rate (1%), proportion of cases converted to open (5.0%), major BDI rate (0.4%), and mean length of stay (3 days) all decreased over the study period. 52,242 (12.5%) cases were carried out during an emergency admission and uptake has remained stable over the decade. Emergency surgery was more likely to be performed at high-volume centres (odds ratio [OR] 1.39, 95% confidence interval [CI] 1.35-1.44) and specialist units (OR 1.32, 95% CI 1.30-1.35). High-volume centres were more likely to complete emergency cases laparoscopically (OR 1.11, 95% CI 1.05-1.18). Multivariate regression analysis demonstrated that patient- (male gender, increasing age, and comorbidity) and disease-specific (inflammatory pathology and emergency admission) factors rather than hospital institutional characteristics (annual cholecystectomy volume and presence of specialist surgical units) were associated with poorer outcomes. CONCLUSIONS: The provision of laparoscopic cholecystectomy in England has increased. This has been associated with improvements in outcomes such as mortality and length of stay. However, emergency cholecystectomy uptake remains sub-optimal and is more likely to be performed at high-volume or specialist hospitals without adverse outcomes. Further research into the routine provision of emergency cholecystectomy in England is needed in order to optimize patient outcomes.

Volume-outcome relationships in lower extremity arterial bypass surgery.

OBJECTIVE: We sought to investigate whether a volume-outcome relationship exists for lower extremity arterial bypass (LEAB) surgery. METHODS: All LEAB procedures performed in England between 2002 and 2006 were identified from Hospital Episode Statistics data. A Charlson-type risk profile, including operating hospital annual case volume, was identified per patient. Outcome measures of revision bypass, amputation, death and a composite measure were established during the index admission and at 1 year.Quintile analysis and multilevel multivariate modeling were used to identify the existence of a volume-outcome relationship and allow adjustment of results for significant determinants of outcome. RESULTS: A total of 27,660 femoropopliteal bypass and 4161 femorodistal bypass procedures were identified.As volume increased, in-hospital mortality after popliteal bypass decreased from 6.5% to 4.9% (P = 0.0045), with a corresponding odds ratio of 0.980 [95% confidence interval (CI), 0.929-0.992; P = 0.014] for every increase of 50 patients per year. Major amputation decreased from 4.1% to 3.2% (P = 0.006) in high-volume hospitals, with a reduction in risk of 0.955 (95% CI, 0.928-0.983; P = 0.002) at 1 year.For distal bypass, in-hospital mortality decreased from 9.8% to 5.5% (P = 0.004) and 1-year major amputation decreased from 25.4% to 18.2% (P < 0.001), with a corresponding odds ratio of 0.658 (95% CI, 0.517-0.838; P < 0.0001) as the volume increased.An increase in the chance of revision surgery (10.6% vs 8.2%, P < 0.001) was seen with higher volume, with an increased odds ratio of 1.031 (95% CI, 1.005-1.057; P = 0.018). CONCLUSIONS: A positive volume-outcome relationship exists for LEAB procedures even after employing multilevel risk adjustment models. There are benefits in terms of mortality and limb salvage both in the short-term and at 1 year postsurgery.

Predictive value of peak systolic velocity for the development of graft limb complications after endovascular aneurysm repair.

PURPOSE: To determine the role of peak systolic velocity (PSV) data provided by duplex ultrasound (DUS) surveillance in the prediction of endograft limb complications after endovascular aneurysm repair (EVAR). METHODS: All 478 consecutive patients (425 men; mean age 75±7 years) who underwent infrarenal EVAR between 2004 and 2010 had DUS scans at 1.5, 3, 6, 9, 12, and 18 months and annually thereafter over a median follow-up of 43 months (range 1-92). In a retrospective study, the PSV recorded from the proximal and distal regions of each stent-graft limb was extracted from each postoperative DUS scan for each patient up to the penultimate scan before diagnosis of a limb complication (limb occlusion, symptomatic or hemodynamically significant kinking, or hemodynamically significant DUS-defined stenosis) requiring reintervention. The median (range) PSV readings from the proximal and distal regions of each stent-graft limb over the course of follow-up were compared between patients who developed a limb complication (n = 38) and those who did not (n = 440). Time-dependent Cox proportional hazards modeling was performed after risk adjustment; results are presented as the hazard ratio (HR) and 95% confidence interval (CI). RESULTS: In the proximal stent-graft limb segment, the median PSV was 106 cm/s (42-308) in patients without limb complications vs. 121 cm/s (50-281) in those with limb complications. Corresponding values in the distal segment of the endograft limb were 113 cm/s (35-400) vs. 129 cm/s (58-420). After risk adjustment, increased PSV over time within both the proximal and distal segments of the stent-graft limb was significantly associated with the risk of limb complications (proximal HR 1.015, 95% CI 1.003 to 1.028, p = 0.014; distal HR 1.010, 95% CI 1.001 to 1.020, p = 0.025). CONCLUSION: Increases in the peak systolic velocity in stent-graft limbs were associated with an increased risk of limb complication, though no predictive threshold could be identified from scans prior to the development of a complication. This observation requires external validation and further investigation to define its clinical utility.

Seasonal variability and meteorological factors: retrospective study of the incidence of pulmonary embolism from a large United kingdom teaching hospital.

BACKGROUND: Seasonal variations in the incidence of pulmonary embolism (PE) have been reported. It has been suggested that changes in meteorological factors may explain this variation. Previous studies have provided inconsistent results, possibly as a result of a small number of observations, in some studies and confounding factors. OBJECTIVE: To investigate whether there is a seasonal variation in the incidence of idiopathic PE and to investigate its relationship with atmospheric pressure, humidity, and temperature. METHODS: A large retrospective study was conducted. All confirmed cases of PE at our institution over a 9-year period were included, except for those patients with a major risk factor for PE. Meteorological data were obtained from a local weather station. Days when there was at least one episode of PE (event day) were compared with days when there were no episodes of PE (non-event day). RESULTS: There were a total of 640 episodes of PE. There was a statistically significant lower percentage of event days in spring (13.8%), compared with the rest of the year (18.3%) (P = .003). The incidence of PE was related to decreased atmospheric pressure and increased temperature. For atmospheric pressure the relationship was most significant for the mean atmospheric pressure for the 2 days preceding clinical presentation with PE (P = .02). For temperature the relationship was most significant for the mean temperature for the 5 days preceding clinical presentation with PE (P = .04). CONCLUSIONS: The results confirm the presence of seasonal variations in episodes of idiopathic PE and an association between decreased atmospheric pressure and increased temperature.

Ventricular pauses during atrial fibrillation predict relapse after electrical cardioversion: a prospective study.

AIMS: To investigate the use of ambulatory electrocardiogram (ECG) monitoring in atrial fibrillation (AF) to predict recurrence after electrical cardioversion (ECV). METHODS: RR interval variables were obtained from 24 hours ECGs recorded before ECV in 119 patients (85 men, age 66 +/- 10 years) with persistent AF. Patients were followed for 1 month. RESULTS: Of the 119 patients, 16 (13%) failed ECV and 65 (55%) were in AF at 1 week and 81 (68%) at 1 month after ECV. The maximum RR interval (RR-max) and the minimum RR interval (RR-min) during AF were found to be reproducible. The RR-max was longer in those who had AF 1 week (2.55 +/- 0.49 vs 2.01 +/- 0.52 seconds, P = 0.005) and 1 month (2.56 +/- 0.50 vs 1.89 +/- 0.43 ms; P < 0.001) after ECV than in those who maintained sinus rhythm. Those in AF at 1 month included more patients with RR-max > or = 2.8 seconds (31% vs 11% P = 0.021). The average heart rate was lower in patients with RR-max > or = 2.8 seconds, but the average rate was not predictive of AF recurrence. CONCLUSION: Ventricular pauses during AF predict relapse after ECV.

Air pollution and activation of implantable cardioverter defibrillators in London.

BACKGROUND: Air pollution may increase the incidence of ventricular cardiac arrhythmias. We investigated this in patients with implantable cardioverter defibrillators attending London clinics. METHOD: We explored associations between dates of activation of defibrillators and daily concentrations of various metrics of particulate matter and of pollutant gases at lags from 0 to 5 days, using a fixed-stratum case-crossover analysis controlling for confounding factors. RESULTS: Over an average of 1200 days of observation, 705 patients experienced 5462 activation days. Of 11 pollutants considered, we found positive associations with particle sulfate, particulate matter with aerodynamic diameter less than 10 microm and less than 2.5 microm, ozone, and sulfur dioxide. Only the association for particle sulfate was not easily explainable by chance (for 1 microg/m, lag 0-1 day, odds ratio = 1.025 [95% confidence interval = 1.003 to 1.047]). There was little or no evidence of associations with markers of primary vehicle emissions (particle number concentration, black smoke, nitrogen oxides, and carbon monoxide). There was little evidence of interactions with clinical factors such as ischemic heart disease, frequency of activation, or cardiac drugs. CONCLUSION: Overall there was little evidence of an association between air pollution and activation of implantable cardioverter defibrillators. The pollutants with positive associations tended to be those of secondary origin with a regional distribution, rather than primary pollutants emitted from transport sources.

Goal-directed therapy in high-risk surgical patients: a 15-year follow-up study.

PURPOSE: Goal-directed therapy in the perioperative setting has been shown to be associated with short-term improvements in outcome. This study assesses the longer-term survival of patients from a previous randomized controlled trial of goal-directed therapy in high-risk surgical patients. METHODS: All patients from a previous randomized controlled study were followed up for 15 years following randomization to ascertain their length of survival following surgery. Factors that may be associated with increased survival were evaluated to determine what influenced long-term outcomes. RESULTS: Data from 106 of the original 107 patients (99%) were available for analysis. At 15 years, 11 (20.7%) of the goal-directed therapy patients versus 4 (7.5%) of the control group were alive (p = 0.09). Median survival for the goal-directed group was increased by 1,107 days (1,781 vs. 674 days, p = 0.005). Long-term survival was associated with three independent factors: age [hazard ratio (HR) 1.04 (1.02-1.07), p < 0.0001], randomization to the goal-directed group of the study [HR 0.61 (0.4-0.92), p = 0.02], and avoidance of a significant postoperative cardiac complication [HR 3.78 (2.16-6.6), p = 0.007]. CONCLUSIONS: Long-term survival after major surgery is related to a number of factors, including patient age and avoidance of perioperative complications. Short-term goal-directed therapy in the perioperative period may improve long-term outcomes, in part due to its ability to reduce the number of perioperative complications.

The prevalence of neovascularity in patients clinically diagnosed with rotator cuff tendinopathy.

BACKGROUND: Shoulder dysfunction is common and pathology of the rotator cuff tendons and subacromial bursa are considered to be a major cause of pain and morbidity. Although many hypotheses exist there is no definitive understanding as to the origin of the pain arising from these structures. Research investigations from other tendons have placed intra-tendinous neovascularity as a potential mechanism of pain production. The prevalence of neovascularity in patients with a clinical diagnosis of rotator cuff tendinopathy is unknown. As such the primary aim of this pilot study was to investigate if neovascularity could be identified and to determine the prevalence of neovascularity in the rotator cuff tendons and subacromial bursa in subjects with unilateral shoulder pain clinically assessed to be rotator cuff tendinopathy. The secondary aims were to investigate the association between the presence of neovascularity and pain, duration of symptoms, and, neovascularity and shoulder function. METHODS: Patients with a clinical diagnosis of unilateral rotator cuff tendinopathy referred for a routine diagnostic ultrasound (US) scan in a major London teaching hospital formed the study population. At referral patients were provided with an information document. On the day of the scan (on average, at least one week later) the patients agreeing to participate were taken through the consent process and underwent an additional clinical examination prior to undergoing a bilateral grey scale and colour Doppler US examination (symptomatic and asymptomatic shoulder) using a Philips HDI 5000 Sono CT US machine. The ultrasound scans were performed by one of two radiologists who recorded their findings and the final assessment was made by a third radiologist blinded both to the clinical examination and the ultrasound examination. The findings of the radiologists who performed the scans and the blinded radiologist were compared and any disagreements were resolved by consensus. RESULTS: Twenty-six patients agreed to participate and formed the study population. Of these, 6 subjects were not included in the final assessment following the pre-scan clinical investigation. This is because one subject had complete cessation of symptoms between the time of the referral and entry into the trial. Another five had developed bilateral shoulder pain during the same period. The mean age of the 20 subjects forming the study population was 50.2 (range 32-69) years (SD = 10.9) and the mean duration of symptoms was 22.6 (range .75 to 132) months (SD = 40.1). Of the 20 subjects included in the formal analysis, 13 subjects (65%) demonstrated neovascularity in the symptomatic shoulder and 5 subjects (25%) demonstrated neovascularity in the asymptomatic shoulder. The subject withdrawn due to complete cessation of symptoms was not found to have neovascularity in either shoulder and of the 5 withdrawn due to bilateral symptoms; two subjects were found to have signs of bilateral neovascularity, one subject demonstrated neovascularity in one shoulder and two subjects in neither shoulder. CONCLUSIONS: This study demonstrated that neovascularity does occur in subjects with a clinical diagnosis of rotator cuff tendinopathy and to a lesser extent in asymptomatic shoulders. In addition, the findings of this investigation did not identify an association between the presence of neovascularity; and pain, duration of symptoms or shoulder function. Future research is required to determine the relevance of these findings.

Effect of endovascular aneurysm repair on the volume-outcome relationship in aneurysm repair.

BACKGROUND: We aim to quantify the relationship between the annual caseload (volume) and outcome from elective endovascular (EVR) or open repair of abdominal aortic aneurysms (AAAs) in England between 2005 and 2007. METHODS AND RESULTS: Individual patient data were obtained from the Hospital Episode Statistics. Statistical methods included multiple logistic regression models, mortality control charts, and safety plots to determine the nature of any relationship between volume and outcome. The case-mix between hospitals of different sizes was examined using observed and expected values for in-hospital mortality. Outcome measures included in-hospital mortality and hospital length of stay. Between 2005 and 2007, a total of 57 587 patients were admitted to hospitals in England with a diagnosis of AAA, and 11 574 underwent AAA repair. There were 7313 elective AAA repairs, of which 5668 (78%) were open and 1645 (22%) were EVR. In-hospital mortality rates were 5.63% for all elective AAA repairs with rates of 6.18% for open repair and 3.77% for EVR (odds ratio, 0.676; 95% CI, 0.501 to 0.913; P=0.011). High-volume aneurysm services were associated with significantly lower mortality rates overall (0.991; 0.988 to 0.994; P<0.0001), for open repairs (0.994; 0.991 to 0.998; P=0.0008), and EVR (0.989; 0.982 to 0.995; P=0.0007). Large endovascular units had low mortality rates for open repairs. CONCLUSIONS: A strong relationship existed between the volume of surgery performed and outcome from both open and endovascular aneurysm repairs. These data support the concept that abdominal aortic surgery should be performed in specialized units that meet a minimum volume threshold.

Bench-to-bedside review: the importance of the precision of the reference technique in method comparison studies--with specific reference to the measurement of cardiac output.

Bland-Altman analysis is used for assessing agreement between two measurements of the same clinical variable. In the field of cardiac output monitoring, its results, in terms of bias and limits of agreement, are often difficult to interpret, leading clinicians to use a cutoff of 30% in the percentage error in order to decide whether a new technique may be considered a good alternative. This percentage error of +/- 30% arises from the assumption that the commonly used reference technique, intermittent thermodilution, has a precision of +/- 20% or less. The combination of two precisions of +/- 20% equates to a total error of +/- 28.3%, which is commonly rounded up to +/- 30%. Thus, finding a percentage error of less than +/- 30% should equate to the new tested technique having an error similar to the reference, which therefore should be acceptable. In a worked example in this paper, we discuss the limitations of this approach, in particular in regard to the situation in which the reference technique may be either more or less precise than would normally be expected. This can lead to inappropriate conclusions being drawn from data acquired in validation studies of new monitoring technologies. We conclude that it is not acceptable to present comparison studies quoting percentage error as an acceptability criteria without reporting the precision of the reference technique.

Diagnosis of Clostridium difficile infection by toxin detection kits: a systematic review.

Clostridium difficile can be a fatal hospital-acquired infection and its prevalence has increased. Accurate diagnosis of C difficile is essential for patient management, infection control, and for defining its epidemiology. We did a systematic review of commonly used commercial assays for detection of C difficile toxin (CDT) A and B in stool samples. By comparison of detection of CDT in cell culture with or without selective culture for C difficile, the median sensitivities and specificities (IQR) were as follows: Meridian Premier 0.95 (0.86-0.97) and 0.97 (0.95-0.98), TechLab Tox A/B II 0.83 (0.82-0.85) and 0.99 (0.98-1.00), TechLab Tox A/B Quik Chek 0.84 (0.81-0.87) and 1.00 (0.99-1.00), Remel Xpect 0.82 (0.75-0.89) and 0.96 (0.95-0.98), Meridian Immunocard 0.90 (0.84-0.92) and 0.99 (0.98-1.00), and BioMérieux VIDAS 0.76 and 0.93. If the prevalence of CDT A and B in stool samples is relatively low (<10%), the positive predictive value of these assays is unacceptably low (eg, <50% in some circumstances) and will vary depending on the assay and number of samples tested. This low positive predictive value impinges on clinical management, outbreaks, and makes epidemiological data unreliable. To improve diagnosis, we suggest a two-stage testing strategy for C difficile toxin with an initial highly sensitive rapid screening test to identify positive samples that are then confirmed by a reference method.

Differential pathways govern CD4+ CD28- T cell proinflammatory and effector responses in patients with coronary artery disease.

Patients with acute coronary syndromes experience circulatory and intraplaque expansion of an aggressive and unusual CD4(+) lymphocyte subpopulation lacking the CD28 receptor. These CD4(+)CD28(-) cells produce IFN-gamma and perforin, and are thought to play an important role in coronary atheromatous plaque destabilization. Aberrant expression of killer Ig-like receptors (KIRs) in CD4(+)CD28(-) cells is broadly thought to be responsible for their cytotoxicity, but the mechanisms involved remain poorly defined. We therefore sought to investigate the mechanism and regulation of CD4(+)CD28(-) cell functionality using T cell clones (n = 536) established from patients with coronary artery disease (n = 12) and healthy volunteers (n = 3). Our functional studies demonstrated that KIR2DS2 specifically interacted with MHC class I-presenting human heat shock protein 60 (hHSP60) inducing cytotoxicity. Further investigations revealed the novel finding that hHSP60 stimulation of TCR alone could not induce a cytotoxic response, and that this response was specific and KIR dependent. Analysis of CD4(+)CD28(-)2DS2(+) clones (n = 162) showed that not all were hHSP60 cytotoxic; albeit, their prevalence correlated with coronary disease status (p = 0.017). A higher proportion of clones responded to hHSP60 by IFN-gamma compared with perforin (p = 0.008). In this study, for the first time, we define the differential regulatory pathways involved in CD4(+)CD28(-) cell proinflammatory and effector responses. We describe in this study that, contrary to previous reports, CD4(+)CD28(-) cell recognition and killing can be specific and discriminate. These results, in addition to contributing to the understanding of CD4(+)CD28(-) cell functionality, may have implications for the monitoring and management of coronary artery disease progression.