Biomedical subjects

Bruce E Keogh

Publications and source records attributed to Bruce E Keogh.

10 recordsLinked to original sources

PubMed2006

Glucose-insulin-potassium and tri-iodothyronine individually improve hemodynamic performance and are associated with reduced troponin I release after on-pump coronary artery bypass grafting.

BACKGROUND: Both glucose-insulin-potassium (GIK) and tri-iodothyronine (T3) may improve cardiovascular performance after coronary artery surgery (CABG) but their effects have not been directly compared and the effects of combined treatment are unknown. METHODS AND RESULTS: In 2 consecutive randomized double-blind placebo-controlled trials, in patients undergoing first time isolated on-pump CABG between January 2000 and September 2004, 440 patients were recruited and randomized to either placebo (5% dextrose) (n=160), GIK (40% dextrose, K+ 100 mmol.L(-1), insulin 70 u.L(-1)) (0.75 mL.kg(-1) h(-1)) (n=157), T3 (0.8 microg.kg(-1) followed by 0.113 microg.kg(-1) h(-1)) (n=63) or GIK+T3 (n=60). GIK/placebo therapy was administered from start of operation until 6 hours after removal of aortic cross-clamp (AXC) and T3/placebo was administered for a 6-hour period from removal of AXC. Serial hemodynamic measurements were taken up to 12 hours after removal of AXC and troponin I (cTnI) levels were assayed to 72 hours. Cardiac index (CI) was significantly increased in both the GIK and GIK/T3 group in the first 6 hours compared with placebo (P<0.001 for both) and T3 therapy (P=0.009 and 0.029, respectively). T3 therapy increased CI versus placebo between 6 and 12 hours after AXC removal (P=0.01) but combination therapy did not. Release of cTnI was lower in all treatment groups at 6 and 12 hours after removal of AXC. CONCLUSIONS: Treatment with GIK, T3, and GIK/T3 improves hemodynamic performance and results in reduced cTnI release in patients undergoing on-pump CABG surgery. Combination therapy does not provide added hemodynamic effect.

Aged↗

PubMed2006

Patient-prosthesis mismatch does not affect survival following aortic valve replacement.

OBJECTIVE: Patient-prosthesis mismatch (PPM) has been reported to increase perioperative mortality and reduce postoperative survival in patients undergoing aortic valve replacement (AVR). We analysed the effect of PPM at values predicting severe mismatch on survival following AVR in our unit. METHODS: Prospectively collected data on 1481 consecutive patients who had undergone AVR with or without coronary artery revascularisation between 1997 and 2005 were analysed. Projected in vitro valve effective orifice area (EOA) and geometric prosthesis internal orifice area (GOA) were evaluated and values were indexed to body surface area (cm(2)m(-2)). PPM was defined as EOAi<0.6 and/or GOAi<1.1. Long-term survival data were obtained from the National Institute of Statistics. RESULTS: One thousand four hundred and eighteen patients were identified. 67/1418 (4.7%) patients had GOAi<1.1; 122/1418 (8.6%) had EOAi<0.6 and 38 (2.6%) patients exhibited both forms of mismatch. One thousand two hundred and sixty-seven patients (89%) demonstrated no mismatch (reference group). There were 75 in-hospital deaths (overall mortality 5.3%) with no significant difference between the mismatch and the reference groups. Survival data were available for up to 8 years (median 36 months, IQR 6-60 months). There were 160 late deaths (13/143 PPM group vs 147/1198 reference group). The 5-year survival estimate was similar for both groups (83% PPM group; 81% reference group; p=0.47). Cox-hazard analysis identified advanced age as the only predictor of reduced survival (age>80, RR 2.13, 95% CI 1.38-4.586, p=0.004). CONCLUSIONS: Severe patient-prosthesis mismatch was predicted in 4-10% of patients undergoing AVR but this did not affect in-hospital mortality or mid-term survival.

Adult↗

PubMed2006

Total arterial revascularization is safe: multicenter ten-year analysis of 71,470 coronary procedures.

BACKGROUND: The purpose of this study was to assess the use of arterial revascularization and to compare the in-hospital mortality with other CABG grafting strategies. METHODS: A total of 71,470 CABG patients (1992-2001) in 27 centers in the United Kingdom were studied. The proportion of patients with arterial revascularization was compared. In-hospital mortality was compared for various grafting strategies: all-arterial (n = 5,401), all non-all-arterial patients (n = 66,069), one artery any number of veins (n = 49,801). The groups were compared for in-hospital mortality using multivariate logistic regression to assess the independent effect of the grafting strategies on mortality; logistic EuroSCORE-predicted mortality was compared to actual mortality, and all arterial and one artery and veins patients were compared with propensity score analysis. RESULTS: There was a significant increase in the proportion of all-arterial patients over time (3.2% to 11.7%, p < 0.001) with evidence of variability across centers. Crude mortality for all-arterial patients was 2% vs 3% for all non-all-arterial patients (p < 0.001). In multivariate analysis, all-arterial was associated with a slight but insignificant increase in in-hospital mortality (odds ratio [OR] 1.13; [95% confidence interval {CI} 0.86-1.48], p = 0.36). There was a trend toward higher mortality in the all-arterial group when compared with the one artery and veins group (OR 1.19 [95% CI 0.91-1.56], p = 0.10). The one artery and veins group was the only group where actual mortality was significantly lower than predicted by EuroSCORE (p < 0.001). In propensity analysis the mortality was 1.51% for one artery and veins and 1.74% of all-arterial patients (p = 0.56). CONCLUSIONS: The use of arterial grafting has increased over time, varies by center, and appears to be safe in terms of in-hospital mortality.

Aged↗

PubMed2006

Improved myocardial protection during coronary artery surgery with glucose-insulin-potassium: a randomized controlled trial.

OBJECTIVE: We sought to assess the role of glucose-insulin-potassium in providing myocardial protection in nondiabetic patients undergoing coronary artery surgery with cardiopulmonary bypass. METHODS: A prospective, randomized, double-blind, placebo-controlled trial was conducted at a single-center university hospital performing adult cardiac surgery. Two hundred eighty nondiabetic adult patients undergoing first-time elective or urgent isolated multivessel coronary artery bypass grafting were prospectively randomized to receive glucose-insulin-potassium infusion or placebo (dextrose 5%) before, during, and for 6 hours after surgical intervention. Anesthetic, cardiopulmonary bypass, myocardial protection, and surgical techniques were standardized. The primary end point was postreperfusion cardiac index. Secondary end points were systemic vascular resistance index, the incidence of low cardiac output episodes, inotrope and vasoconstrictor use, and biochemical-electrocardiographic evidence of myocardial injury. The incidence of dysrhythmias and infections requiring treatment was recorded prospectively. RESULTS: The glucose-insulin-potassium group experienced higher cardiac indices (P < .001) throughout infusion and reduced vascular resistance (P < .001). The incidence of low cardiac output episodes was 15.9% (22/138) in the glucose-insulin-potassium group and 27.5% (39/142) in the placebo group (P = .021). Inotropes were required in 18.8% (26/138) of the glucose-insulin-potassium group and 40.8% (58/142) of the placebo group (P < .001). Fewer patients in the glucose-insulin-potassium group (12.3% [16/133]) versus those in the placebo group (23.4% [32/137]) had significant myocardial injury (P = .017). Noncardiac morbidity was not different. CONCLUSION: Glucose-insulin-potassium therapy improves early postoperative cardiovascular performance, reduces inotrope requirement, and might reduce myocardial injury. These potential benefits are not at the expense of increased noncardiac morbidity.

Cardiomyopathies↗

PubMed2005

Relation between mild renal dysfunction and outcomes after coronary artery bypass grafting.

BACKGROUND: Risk stratification algorithms for coronary artery bypass grafting (CABG) do not include a weighting for preoperative mild renal impairment defined as a serum creatinine 130 to 199 micromol/L (1.47 to 2.25 mg/dL), which may impact mortality and morbidity after CABG. METHODS AND RESULTS: We reviewed prospectively collected data between 1997 and 2004 on 4403 consecutive patients undergoing first-time isolated CABG with a preoperative serum creatinine <200 micromol/L (2.26 mg/dL)] in a single institution. The in-hospital mortality was 2.5% (112 of 4403), the need for new dialysis/hemofiltration was 1.3% (57 of 4403), and the stroke rate was 2.5% (108 of 4403). There were 458 patients with a serum creatinine 130 to 199 micromol/L or 1.47 to 2.25 mg/dL (mild renal dysfunction group) and 3945 patients with a serum creatinine <130 micromol/L (<1.47 mg/dL). Operative mortality was higher in the mild renal dysfunction group (2.1% versus 6.1%; P<0.001) and increased with increasing preoperative serum creatinine level. New dialysis/hemofiltration (0.8%versus 5.2%; P<0.001) and postoperative stroke (2.2% versus 5.0%; P<0.01) were also more common in the patients with mild renal impairment. Multivariate analysis adjusting for known risk factors confirmed preoperative mild renal impairment (creatinine 130 to 199 micromol/L or 1.47 to 2.25 mg/dL; odd ratio, 1.91; 95% CI, 1.18 to 3.03; P=0.007) or glomerular filtration rate estimates <60 mL/min per 1.73 m2, derived using the Cockroft-Gault formula, (odds ratio, 1.98; 95% CI, 1.16 to 3.48; P=0.015) as independent predictors of in-hospital mortality. Preoperative mild renal dysfunction adversely affected the 3-year survival probability after CABG (93% versus 81%; P<0.001). CONCLUSIONS: Mild renal dysfunction is an important predictor of outcome in terms of in-hospital mortality, morbidity, and midterm survival in patients undergoing CABG.

Aged↗

PubMed2005

Generic, simple risk stratification model for heart valve surgery.

BACKGROUND: Heart valve surgery has an associated in-hospital mortality rate of 4% to 8%. This study aims to develop a simple risk model to predict the risk of in-hospital mortality for patients undergoing heart valve surgery to provide information to patients and clinicians and to facilitate institutional comparisons. METHODS AND RESULTS: Data on 32,839 patients were obtained from the Society of Cardiothoracic Surgeons of Great Britain and Ireland on patients who underwent heart valve surgery between April 1995 and March 2003. Data from the first 5 years (n=16,679) were used to develop the model; its performance was evaluated on the remaining data (n=16,160). The risk model presented here is based on the combined data. The overall in-hospital mortality was 6.4%. The risk model included, in order of importance (all P<0.01), operative priority, age, renal failure, operation sequence, ejection fraction, concomitant tricuspid valve surgery, type of valve operation, concomitant CABG surgery, body mass index, preoperative arrhythmias, diabetes, gender, and hypertension. The risk model exhibited good predictive ability (Hosmer-Lemeshow test, P=0.78) and discriminated between high- and low-risk patients reasonably well (receiver-operating characteristics curve area, 0.77). CONCLUSIONS: This is the first risk model that predicts in-hospital mortality for aortic and/or mitral heart valve patients with or without concomitant CABG. Based on a large national database of heart valve patients, this model has been evaluated successfully on patients who had valve surgery during a subsequent time period. It is simple to use, includes routinely collected variables, and provides a useful tool for patient advice and institutional comparisons.

Cardiac Surgical Procedures↗

PubMed2005

A technique for salvaging a critical internal mammary artery bypass graft damaged during resternotomy.

Resternotomy in the presence of a patent internal mammary artery graft poses an addition hazard to the reoperation. We describe a situation in which the patent mammary artery graft to the left anterior descending artery was severed and retracted during sternal reentry for an aortic valve replacement. We illustrate a simple technique for restoring the blood supply using a coronary artery shunt.

Aged↗

PubMed2005

An attempt at data verification in the EACTS Congenital Database.

OBJECTIVE: The multi-national and multi-institutional collection of data on outcomes in Congenital Heart Surgery (CHS) provides the possibility of analysis of results of treatment and may result in further improvement of the quality of care. The verification of data as far as the completeness and accuracy is necessary to give confidence to all sides--the patients, centers and regulatory authorities. The source data verification (SDV), although difficult, appears possible even in such a large-scale database. METHODS: Out of 5.274 patients and 5.612 procedures data of 2003, collected in the database, 1.703 (32.3%) and 1.895 (33.8%), respectively, have been verified at five sites on following fields: IPPV time, date of birth, date of admission, date of surgery, date of discharge/mortality, body weight, case category, CPB time, AoX time, Circulatory arrest time. SDV was performed at five sites by two database officers using the sources of information different to the local copy of the database (patients' files, operation notes, perfusion charts, OR Books). Verification was performed between June 1st and July 31st 2004. Statistical analysis was performed using R-project software, ver. 2.0.0. and Welch's t-test for comparison of continuous variables. P-value >0.05 was used as statistically significant difference between groups. RESULTS: Pre- and post-verification mortalities in all groups showed no significant differences although seven deaths out of 68 (10.27%) were missed. None of the other verified fields showed significant differences after verification. CONCLUSIONS: Source Data Verification showed no statistically significant differences between verified and non-verified data on 30 days mortality, LOS, age, body weight, CPB time, AoX and Circulatory arrest time. IPPV time was not available in 58.6% procedures.

Data Collection↗

PubMed2003

How to evaluate and improve the quality and credibility of an outcomes database: validation and feedback study on the UK Cardiac Surgery Experience.

OBJECTIVES: To assess the quality and completeness of a database of clinical outcomes after cardiac surgery and to determine whether a process of validation, monitoring, and feedback could improve the quality of the database. DESIGN: Stratified sampling of retrospective data followed by prospective re-sampling of database after intervention of monitoring, validation, and feedback. SETTING: Ten tertiary care cardiac surgery centres in the United Kingdom. INTERVENTION: Validation of data derived from a stratified sample of case notes (recording of deaths cross checked with mortuary records), monitoring of completeness and accuracy of data entry, feedback to local data managers and lead surgeons. MAIN OUTCOME MEASURES: Average percentage missing data, average kappa coefficient, and reliability score by centre for 17 variables required for assignment of risk scores. Actual minus risk adjusted mortality in each centre. RESULTS: The database was incomplete, with a mean (SE) of 24.96% (0.09%) of essential data elements missing, whereas only 1.18% (0.06%) were missing in the patient records (P<0.0001). Intervention was associated with (a) significantly less missing data (9.33% (0.08%) P<0.0001); (b) marginal improvement in reliability of data and mean (SE) overall centre reliability score (0.53 (0.15) v 0.44 (0.17)); and (c) improved accuracy of assigned Parsonnet risk scores (kappa 0.84 v 0.70). Mortality scores (actual minus risk adjusted mortality) for all participating centres fell within two standard deviations of the mean score. CONCLUSION: A short period of independent validation, monitoring, and feedback improved the quality of an outcomes database and improved the process of risk adjustment, but with substantial room for further improvement. Wider application of this approach should increase the credibility of similar databases before their public release.

Cardiac Surgical Procedures↗

PubMed2002

Immunohistologic evidence of myocardial disease in apparently healthy relatives of patients with dilated cardiomyopathy.

OBJECTIVES: This study investigated whether apparently healthy relatives of patients with idiopathic dilated cardiomyopathy (DCM) who have left ventricular enlargement (LVE) have biopsy evidence of underlying myocardial disease. BACKGROUND: Left ventricular enlargement with normal systolic function is common among asymptomatic relatives of patients with DCM. Although there is circumstantial evidence to suggest that LVE may be a marker of early DCM, its pathophysiologic significance remains uncertain. METHODS: Over six years, 767 asymptomatic relatives of 183 consecutive patients with DCM were evaluated: 37 (5%) had DCM and 104 (14%) had LVE (left ventricular end-diastolic dimension >112% predicted) with normal systolic function. Right ventricular biopsy was performed in 32 relatives with LVE, 14 patients with symptomatic DCM and 6 control subjects with normal ventricular function undergoing elective coronary artery bypass graft surgery. Histologic and immunohistochemical analyses, including quantitative double immunofluorescence, were performed for leukocyte markers (CD3 and CD68), intercellular adhesion molecule-1 (ICAM-1) and human leukocyte antigen class II antigens (DR and DQ). RESULTS: Histologic findings consistent with DCM were present in 50% of the patients with DCM, 25% of the relatives with LVE and 0% of the control subjects. The median CD3 count was 2.4/mm(2) in patients with DCM, 4/mm(2) in relatives with LVE and 0 in control subjects (p = 0.04). Using a threshold of >7 cells/mm(2), 21% of patients with DCM and 25% of relatives with LVE were CD3-positive (p = 0.01). Quantitative analysis demonstrated DR expression on 55.8+/-22.8%, 63.5+/-18.8% and 30.9+/-15.7% of the endothelial surface in patients with DCM, relatives and control subjects, respectively (p = 0.003). Corresponding values for ICAM expression were 35.6+/-15.1%, 36.7+/-14.5% and 17.3+/-7.9% (p = 0.013). When combining inflammatory and histologic changes, 28 (86%) of LVE, 14 (100%) of DCM and no control biopsies were abnormal (p < 0.001). CONCLUSIONS: Most asymptomatic relatives of patients with DCM with LVE have histopathologic and immunopathologic findings similar to those of patients with established disease. Clinical identification and follow-up of such individuals are warranted to prevent presentation with advanced DCM and to enable assessment of interventions aimed at attenuating disease progression.

Adult↗