The European Association for Cardio-Thoracic Surgery (EACTS) database: an introduction.

OBJECTIVES: Continuous monitoring of surgical outcomes through benchmarking and the identification of best practices has become increasingly important. A structured approach to data collection, coupled with validation, analysis and reporting, is a powerful tool in these endeavours. However, inconsistencies in standards and practices have made comparisons within and between European countries cumbersome. The European Association for Cardio-Thoracic Surgery (EACTS) has established a large international database with the goals of (i) working with other organizations towards universal data collection and creating a European-wide repository of information on the practice of cardio-thoracic surgery, and (ii) disseminating that information in scientific, peer-reviewed articles. We report on the process of data collection, as well as on an overview of the data in the database. METHODS: The EACTS Database Committee met for the first time in Monaco, September 2002, to establish the ground rules for the process of setting up the database. Subsequently, data have been collected and merged by Dendrite Clinical Systems Ltd. RESULTS: As of December 2008, the database included 1,074,168 patient records from 366 hospitals located in 29 countries. The latest submission from the years 2006-08 included 404,721 records. The largest contributors were the UK (32.0%), Germany (20.9%) and Belgium (7.3%). Isolated coronary bypass surgery was the most frequently performed operation; the proportion of surgical workload that comprised isolated coronary artery bypass grafting varied from country to country: 30% in Spain and almost 70% in Denmark. Isolated valve procedures constituted 12% of all procedures in Norway and 32% in Spain. Baseline demographics showed an increase in the mean age and the percentage of patients that were female over time. Remarkably, the mortality rates for all procedures declined over the period analysed, to 2.2% (95% confidence interval [CI] 2.2-2.3%) for isolated coronary bypass, 3.4% (95% CI 3.3-3.5%) for isolated valve and 6.2% (95% CI 6.0-6.5%) for bypass + valve procedures. CONCLUSION: The EACTS database has proven to be an important step forward in providing opportunities for monitoring cardiac surgical care across Europe. As the database continues to expand, it will facilitate research projects, establish benchmarking standards and identify potential areas for quality improvements.

The development of a postoperative morbidity score to assess total morbidity burden after cardiac surgery.

OBJECTIVE: To develop a tool for identifying and quantifying morbidity following cardiac surgery (cardiac postoperative morbidity score [C-POMS]). STUDY DESIGN AND SETTING: Morbidity was prospectively assessed in 450 cardiac surgery patients on postoperative days 1, 3, 5, 8, and 15 using POMS criteria (nine postoperative morbidity domains in general surgical patients) and cardiac-specific variables (from expert panel). Other morbidities were noted as free text and included if prevalence was more than 5%, missingness less than 5%, and mean expert-rated severity-importance index score more than 8. Construct validity was assessed by expert panel review, Cronbach's alpha (internal consistency), and linear regression (predictive ability of C-POMS for length of stay [LOS]). RESULTS: A 13-domain model was derived. Internal consistency (>0.7) on D3-D15 permits use as a summative score of total morbidity burden. Mean C-POMS scores were 3.4 (D3), 2.6 (D5), 3.4 (D8), and 3.8 (D15). Patient LOS was 4.6 days (P=0.012), 5.3 days (P=0.001), and 7.6 days (P=0.135) longer in patients with C-POMS-defined morbidity on D3, D5, D8, and D15, respectively, than in those without. For every unit increase in C-POMS summary score, subsequent LOS increased by 1.7 (D3), 2.2 (D5), 4.5 (D8), and 6.2 (D15) days (all P=0.000). CONCLUSION: C-POMS is the first validated tool for identifying total morbidity burden after cardiac surgery. However, further external validation is warranted.

Tissue oxygen saturation and outcome after cardiac surgery.

BACKGROUND: Cardiopulmonary bypass during cardiac surgery can result in a shortfall in oxygen delivery relative to demand, marked by a decrease in muscle tissue oxygen saturation as blood flow is redistributed to vital organs. Such "tissue shock" might impair postoperative recovery. OBJECTIVES: To determine the association of changes in tissue oxygen saturation with postoperative outcome in cardiac surgery patients. METHODS: In 74 adults undergoing cardiac surgery, tissue oxygen saturation in the thenar eminence was recorded using near-infrared spectroscopy before and during induction of anesthesia, throughout surgery, and in the intensive care unit until extubation or for a maximum monitoring time of 24 hours. The measurements were related to postoperative outcome. RESULTS: Mean tissue oxygen saturation increased from 81.7% to 88.5% with induction of anesthesia and decreased to 78.9% and 69.9% during surgery and on arrival in the intensive care unit, respectively. Saturation increased to 77.8% by 6 hours after surgery and remained stable. Mean saturation during the first minutes of anesthesia and 20 minutes in the intensive care unit was lower in patients with a postoperative morbidity than in patients without such morbidity on day 15 (81.1% vs 87.6%; P = .04) and on day 3 (72.9% vs 85.5%; P = .009). No associations with other outcome measures were observed. CONCLUSIONS: In patients undergoing cardiac surgery, reduced tissue oxygen saturation in the thenar eminence may be associated with poor postoperative outcome. Further studies are needed to confirm these findings and to determine whether measures to improve the balance between oxygen delivery and consumption might improve both tissue oxygen saturation and outcome.

Patient-prosthesis mismatch in patients with aortic stenosis undergoing isolated aortic valve replacement does not affect survival.

BACKGROUND: Data suggest that patient-prosthesis mismatch (PPM) adversely effects late survival after aortic valve replacement (AVR). This study examined the incidence and implications of PPM in patients undergoing isolated AVR. METHODS: Prospectively collected data on patients undergoing isolated AVR for aortic stenosis between January 1, 1997 and December 31, 2007 were analyzed. The projected effective valve orifice area from in vivo data was indexed to body surface area (EOAi). PPM was defined as moderate for EOAi of < or = 0.85 cm(2)/m(2) and severe if < or = 0.6 cm(2)/m(2). The reference group comprised patients with EOAi > 0.85 cm(2)/m(2). The effect of PPM on postoperative survival was assessed by multivariate analysis. RESULTS: Of 801 patients, PPM was severe in 48 (6.0%), moderate in 462 (57.8%), and nonexistent in 291 (36.4%). Mismatch was associated with increasing age and female gender, thus resulting in an increase in the EuroSCORE (reference group, 4.9 +/- 2.6; moderate PPM, 5.8 +/- 2.4; and severe PPM, 6.1+/-2.1; p < 0.001). PPM did not significantly increase hospital mortality. Four deaths occurred in the reference group (1.4%), 12 in the moderate PPM (2.6%), and none in the severe PPM group (p = 0.311). The 5-year survival estimates were 83% in reference, 86% in moderate PPM, and 89% in severe PPM (p = 0.25). By multivariate analysis, PPM was not an independent risk factor for reduced in-hospital or late survival. CONCLUSIONS: Moderate PPM is common in patients undergoing AVR for aortic stenosis, but severe mismatch is rare. Patients with PPM have similar early and late postoperative survival rate.

Are coronary angiograms of value in the risk stratification of patients undergoing coronary artery bypass surgery?

INTRODUCTION: There are currently more than 20 risk-scoring systems that attempt to predict peri-operative mortality following coronary artery bypass surgery (CABG). All these scoring systems use objective criteria to assess operative risk. Angiographic data are currently not included in any of these systems. This pilot study assessed the value of coronary angiography in predicting peri-operative mortality following CABG. PATIENTS AND METHODS: Fourteen patients who died following first-time isolated CABG surgery were identified. These were matched with 14 patients of similar age, sex, left ventricle function and European System for Cardiac Operative Risk Evaluation (EuroSCORE). A panel of 25 clinicians were given details of the patients' age, sex, diabetic status, family history, smoking history, hypertensive status, lipid status, pre-operative symptoms, left ventricle ejection fraction and weight and shown the coronary angiograms of the patient. They were asked to predict the outcome following CABG for each patient. RESULTS: Receiver operator characteristic curves were constructed and the area under the curves calculated and analysed using a commercially available statistical package (PRISM). The area under the curve for the group was 0.6820 for the group. Consultant clinicians achieved an area of 0.6789 versus their trainees 0.6844 (P = NS). The cardiologists achieved an area of 0.7063 versus the cardiothoracic surgeons 0.6491 (P = NS). CONCLUSIONS: Despite the EuroSCORE predicting equal risk for the two groups of patients, it would appear that clinicians are able to identify individual higher risk patients by assessing pre-operatively the quality of the patient's coronary vasculature. Although the clinicians were able to predict individual patient mortality better than the EuroSCORE, the area under the curve indicates that it is not a robust method and clinicians, with all the clinical information to hand, are only moderately good at predicting the outcome following coronary artery bypass surgery.

Mild renal dysfunction predicts in-hospital mortality and post-discharge survival following cardiac surgery.

OBJECTIVES: To assess the impact of preoperative renal dysfunction on in-hospital mortality and late survival outcome following adult cardiac surgery. METHODS: Prospectively collected data were analysed on 7621 consecutive patients not requiring preoperative renal-replacement therapy, who underwent CABG, valve surgery or combined procedures from 1/1/98 to 1/12/06. Preoperative estimated glomerular filtration rate was calculated using Cockcroft-Gault formula. Patients were classified in the four chronic kidney disease (CKD) stage classes defined by the National Kidney Foundation Disease Outcome Quality Initiative Advisory Board. Late survival data were obtained from the UK Central Cardiac Audit Database. RESULTS: There were 243 in-hospital deaths (3.2%). There was a stepwise increase in operative mortality with each CKD class independent of the type of surgery. Multivariate analysis confirmed CKD class to be an independent predictor of in-hospital mortality (class 2 OR 1.45, 95% CI 1.1-2.35, p=0.001; class 3 OR 2.8, 95% CI 1.68-4.46, p=0.0001; class 4 OR 7.5, 95% CI 3.76-15.2, p=0.0001). The median follow-up after surgery was 42 months (IQR 18-74) and there were 728 late deaths. Survival analysis using a Cox regression model confirmed CKD class to be an independent predictor of late survival (class 2 HR 1.2, 95% CI 1.1-1.6, p=0.0001; class 3 HR 1.95, 95% CI 1.6-2.4, p=0.0001; and class 4 HR 3.2, 95% CI 2.2-4.6, p=0.0001). Ninety-eight percent (7517/7621) of patients had a preoperative creatinine <200 micromol/l, which is not included as a risk factor in most risk stratification systems. CONCLUSIONS: Mild renal dysfunction is an important independent predictor of in-hospital and late mortality in adult patients undergoing cardiac surgery.

Bleeding in cardiac surgery: the use of aprotinin does not affect survival.

OBJECTIVE: The antifibrinolytic drug aprotinin has been the most widely used agent to reduce bleeding and its complications in cardiac surgery. Several randomized trials and meta-analyses have demonstrated it to be effective and safe. However, 2 recent reports from a single database have implicated the use of aprotinin as a risk for postoperative complications and reduced long-term survival. METHODS: In this single-institution observational study involving 7836 consecutive patients (1998-2006), we assessed the safety of using aprotinin in risk reduction strategy for postoperative bleeding. RESULTS: Aprotinin was used in 44% of patients. Multivariate analysis identified aprotinin use in risk reduction for reoperation for bleeding (odds ratio, 0.51; 95% confidence interval, 0.36-0.72; P = .001) and need for blood transfusion postoperatively (odds ratio, 0.67; 95% confidence interval, 0.57-0.79; P = .0002). The use of aprotinin did not affect in-hospital mortality (odds ratio, 1.03; 95% confidence interval, 0.71-1.49; P = 0.73), intermediate-term survival (median follow-up, 3.4 years; range, 0-8.9 years; hazard ratio, 1.09; 95% confidence interval, 0.93-1.28; P = .30), incidence of postoperative hemodialysis (odds ratio, 1.16; 95% confidence interval, 0.73-1.85; P = .49), and incidence of postoperative renal dysfunction (odds ratio, 0.78; 95% confidence interval, 0.59-1.03; P = .07). CONCLUSION: This study demonstrates that aprotinin is effective in reducing bleeding after cardiac surgery, is safe, and does not affect short- or medium-term survival.

Deep sternal wound infection requiring revision surgery: impact on mid-term survival following cardiac surgery.

OBJECTIVE: To assess the impact of deep sternal wound infection on in-hospital mortality and mid-term survival following adult cardiac surgery. METHODS: Prospectively collected data on 4586 consecutive patients who underwent a cardiac surgical procedure via a median sternotomy from 1st January 2001 to 31st December 2005 were analysed. Patients with a deep sternal wound infection (DSWI) were identified in accordance with the Centres for Disease Control and Prevention guidelines. Nineteen variables (patient-related, operative and postoperative) were analysed. Logistic regression analysis was used to calculate a propensity score for each patient. Late survival data were obtained from the UK Central Cardiac Audit Database. Mean follow-up of DSWI patients was 2.28 years. RESULTS: DSWI requiring revision surgery developed in 1.65% (76/4586) patients. Stepwise multivariable logistic regression analysis identified age, diabetes, a smoking history and ventilation time as independent predictors of a DSWI. DSWI patients were more likely to develop renal failure, require reventilation and a tracheostomy postoperatively. Treatment included vacuum assisted closure therapy in 81.5% (62/76) patients and sternectomy with musculocutaneous flap reconstruction in 35.5% (27/76) patients. In-hospital mortality was 9.2% (7/76) in DSWI patients and 3.7% (167/4510) in non-DSWI patients (OR 1.300 (0.434-3.894) p=0.639). Survival with Cox regression analysis with mean propensity score (co-variate) showed freedom from all-cause mortality in DSWI at 1, 2, 3 and 4 years was 91%, 89%, 84% and 79%, respectively compared with 95%, 93%, 90% and 86%, respectively for patients without DSWI ((p=0.082) HR 1.59 95% CI (0.94-2.68)). CONCLUSION: DSWI is not an independent predictor of a higher in-hospital mortality or reduced mid-term survival following cardiac surgery in this population.

Toward public disclosure of surgical results: experience of cardiac surgery in the United Kingdom.

Public disclosure of surgical results has been implemented in recent years. This article discusses the disclosure of cardiac surgery results in the United Kingdom.

Pseudothrombocytopenia in cardiac surgical practice.

Pseudothrombocytopenia is observed occasionally in post-cardiac surgical patients. It is commonly due to EDTA-mediated immunological mechanisms, which lead to agglutination of functionally intact platelets. This condition is harmless and does not warrant platelet transfusion. We describe an instance of pseudothrombocytopenia in our practice and discuss its clinical relevance.

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.

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.

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.

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.

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.

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.

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.

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.

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.