Ben Bridgewater

Mitral repair best practice: proposed standards

Objectives: To define best practice standards for mitral valve repair surgery. Design: Development of standards for process and outcome by consensus. Setting: Multidisciplinary panel of surgeons, anaesthetists, and cardiologists with interests and expertise in caring for patients with severe mitral regurgitation. Main outcome measures: Standards for best practice were defined including the full spectrum of multidisciplinary aspects of care. Results: 19 criteria for best practice were defined including recommendations on surgical training, intraoperative transoesophageal echocardiography, surgery for atrial fibrillation, audit, and cardiology and imaging issues. Conclusions: Standards for best practice in mitral valve repair were defined by multidisciplinary consensus. This study gives centres undertaking mitral valve repair an opportunity to benchmark their care against agreed standards that are challenging but achievable. Working towards these standards should act as a stimulus towards improvements in care.

The logistic EuroSCORE in cardiac surgery: How well does it predict operative risk?

Objectives: To study the ability of the logistic EuroSCORE to predict operative risk in contemporary cardiac surgery. Design: Retrospective analysis of prospectively collected data. Setting: All National Health Service centres undertaking adult cardiac surgery in northwest England. Patients: All patients undergoing cardiac surgery between April 2002 and March 2004. Main outcome measures: The predictive ability of the logistic EuroSCORE was assessed by analysing how well it discriminates between patients with differing observed risk by using the area under the receiver operating characteristic (ROC) curve and studying how well it is calibrated against observed in-hospital mortality. The performance of the EuroSCORE was examined in the following surgical subgroups: all cardiac surgery, isolated coronary artery surgery, isolated valve surgery, combined valve and coronary surgery, mitral valve surgery, aortic valve surgery and other surgery. Results: 9995 patients underwent surgery. The discrimination of the logistic EuroSCORE was good with a ROC curve area of 0.79 for all cardiac surgery (range 0.71–0.79 in the subgroups). For all operations, the predicted mortality was 5.7% and observed mortality was 3.3%. The logistic EuroSCORE overpredicted observed mortality for all subgroups but by differing degrees (p  =  0.02) Conclusions: The logistic EuroSCORE is a reasonable overall predictor for contemporary cardiac surgery but overestimates observed mortality. Its accuracy at predicting risk in different surgical subgroups varies. The logistic EuroSCORE should be recalibrated before it is used to gain reassurance about outcomes. Caution should be exercised when using it to compare hospitals or surgeons with a different operative case mix.

Has the publication of cardiac surgery outcome data been associated with changes in practice in northwest England: an analysis of 25 730 patients undergoing CABG surgery under 30 surgeons over eight years

Objectives: To study changes in coronary artery surgery practice in the years spanning publication of cardiac surgery mortality data in the UK. Methods: A retrospective analysis of prospectively collected data from all National Health Service centres undertaking adult cardiac surgery in northwest England was carried out. Patients undergoing coronary artery surgery for the first time between April 1997 and March 2005 were included. Changes in observed, predicted and risk adjusted mortality (EuroSCORE) were studied. Evidence of risk-averse behaviour was looked for by examining the number of patients at low risk (EuroSCORE 0–5), high risk (6–10), and very high risk (11 or more), before and after public disclosure. Results: 25 730 patients underwent coronary artery surgery during the study period. The observed mortality decreased from 2.4% in 1997–8 to 1.8% in 2004–5 (p = 0.014). The expected mortality (EuroSCORE) increased from 3.0 to 3.5 (p<0.001). The observed to expected mortality ratio decreased from 0.8 to 0.51 (p<0.05). The total number and percentage of patients who were at low risk, high risk and very high risk was 2694 (84.6%), 449 (14.1%) and 41 (1.3%) before and 2654 (81.7%), 547 (16.8%) and 47 (1.4%) after public disclosure, respectively, demonstrating a significant increase in the number and proportion of high risk patients undergoing surgery (p<0.001). Conclusions: Publication of cardiac surgery mortality data in the UK has been associated with decreased risk adjusted mortality on retrospective analysis of a large patient database. There is no evidence that fewer high risk patients are undergoing surgery because mortality rates are published.

Aortic valve surgery: Marked increases in volume and significant decreases in mechanical valve use—an analysis of 41,227 patients over 5 years from the Society for Cardiothoracic Surgery in Great Britain and Ireland National database

OBJECTIVES Aortic valve replacement is accepted as a standard treatment for aortic stenosis and regurgitation. To help plan the national requirement for conventional and catheter-based procedures, we have analyzed the Society for Cardiothoracic Surgery in Great Britain and Ireland audit database to look at changes in practice over time. METHODS All patients undergoing conventional aortic valve replacement with or without coronary artery surgery from April 2004 to March 2009 were included. The main outcome measures were changes in the number, characteristics, operative details, and in-hospital mortality. We have looked particularly at trends and outcomes in elderly and high-risk patients (EuroSCORE of 10 or more) who may now be considered for percutaneous aortic valve insertion. RESULTS A total of 41,227 patients underwent aortic valve surgery over 5 years with an in-hospital mortality of 4.1%. The annual number increased from 7396 in 2004-2005 to 9333 in 2008-2009, with significant increases (P < .0005) in mean age (68.8-70.2 years), the proportion of patients with aortic stenosis (62.4%-65.1%), octogenarians (13.6%-18.4%), high-risk patients (24.6%-27.7%), and those receiving biological valves (65.4%-77.8%). The incidence of permanent cerebrovascular accident was 1.2% and 1.0% in patients having only an aortic valve replacement. The dialysis rate was 4.5% and the reoperation rate for bleeding was 6.6%. Overall mortality decreased from 4.4% in 2004-2005 to 3.7% in 2008-2009. Survival to a mean follow-up of 2.5 years was 89%. CONCLUSIONS We have seen a large increase in annual volume of aortic valve replacements, with more patients undergoing surgery for aortic stenosis and an increase in surgery in the elderly and high-risk patients.

Limitations of the Parsonnet score for measuring risk stratified mortality in the north west of England. The North West Regional Cardiac Surgery Audit Steering Group.

OBJECTIVE To study the use of the Parsonnet score to predict mortality following adult cardiac surgery. DESIGN Prospective study. SETTING All centres performing adult cardiac surgery in the north west of England. SUBJECTS 8210 patients undergoing surgery between April 1997 and March 1999. MAIN OUTCOME MEASURES Risk factors and in-hospital mortality were recorded according to agreed definitions. Ten per cent of cases from each centre were selected at random for validation. A Parsonnet score was derived for each patient and its predictive ability was studied. RESULTS Data collection was complete. The operative mortality was 3.5% (95% confidence interval 3.1% to 3.9%), ranging from 2.7% to 3.8% across the centres. On validation, the incidence of discrepancies ranged from 0% to 13% for the different risk factors. The predictive ability of the Parsonnet score measured by area under the receiver operating characteristic curve was 0.74. The mean Parsonnet score for the region was 7.0, giving an observed to expected mortality ratio of 0.51 (range 0.4 to 0.64 across the centres). A new predictive model was derived from the data by multivariate analysis which includes nine objective risk factors, all with a significant association with mortality, which highlights some of the deficits of the Parsonnet score. CONCLUSIONS Risk stratified mortality data were collected on 100% of patients undergoing adult cardiac surgery in two years within a defined geographical region and were used to set an audit standard. Problems with the Parsonnet score of subjectivity, inclusion of many items not associated with mortality, and the overprediction of mortality have been highlighted.

Predicting operative risk for coronary artery surgery in the United Kingdom: a comparison of various risk prediction algorithms

Objective To compare the ability of four risk models to predict operative mortality after coronary artery bypass graft surgery (CABG) in the United Kingdom. Design Prospective study. Setting Two cardiothoracic centres in the United Kingdom. Subjects 1774 patients having CABG. Main outcome measures Risk factors were recorded for all patients, along with in-hospital mortality. Predicted mortality was derived from the American Society of Thoracic Surgeons (STS) risk program, Ontario Province risk score (PACCN), Parsonnet score, and the UK Society of Cardiothoracic Surgeons risk algorithm. Results There were significant differences (p < 0.05) between the British and American populations from which the STS risk algorithm was derived with respect to most variables. The observed mortality in the British population was 3.7% (65 of 1774). The mean pre- dicted mortality by STS score, PACCN, Parsonnet score, and UK algorithms were 1.1%, 1.6%, 4.6%, and 4.7% respectively. The overall predictive ability of the models as measured by the area under the receiver operating characteristic curve were 0.64, 0.60, 0.73, and 0.75, respectively. Conclusions There are differences between the British and American populations for CABG and the North American algorithms are not useful for predicting mortality in the United Kingdom. The UK Society of Cardiothoracic Surgeons algorithm is the best of the models tested but still only has limited predictive ability. Great care must be exercised when using methods of this type for comparisons of units and surgeons.

How does EuroSCORE II perform in UK cardiac surgery; an analysis of 23 740 patients from the Society for Cardiothoracic Surgery in Great Britain and Ireland National Database

Objective The original EuroSCORE models are poorly calibrated for predicting mortality in contemporary cardiac surgery. EuroSCORE II has been proposed as a new risk model. The objective of this study was to assess the performance of EuroSCORE II in UK cardiac surgery. Design A cross-sectional analysis of prospectively collected multi-centre clinical audit data, from the Society for Cardiothoracic Surgery in Great Britain and Ireland Database. Setting All NHS hospitals, and some UK private hospitals performing adult cardiac surgery. Patients 23 740 procedures at 41 hospitals between July 2010 and March 2011. Main outcome measures The main outcome measure was in-hospital mortality. Model calibration (Hosmer–Lemeshow test, calibration plot) and discrimination (area under receiver operating characteristic curve) were assessed in the overall cohort and clinically defined sub-groups. Results The mean age at procedure was 67.1 years (SD 11.8) and 27.7% were women. The overall mortality was 3.1% with a EuroSCORE II predicted mortality of 3.4%. Calibration was good overall but the model failed the Hosmer–Lemeshow test (p=0.003) mainly due to over-prediction in the highest and lowest-risk patients. Calibration was poor for isolated coronary artery bypass graft surgery (Hosmer–Lemeshow, p<0.001). The model had good discrimination overall (area under receiver operating characteristic curve 0.808, 95% CI 0.793 to 0.824) and in all clinical sub-groups analysed. Conclusions EuroSCORE II performs well overall in the UK and is an acceptable contemporary generic cardiac surgery risk model. However, the model is poorly calibrated for isolated coronary artery bypass graft surgery and in both the highest and lowest risk patients. Regular revalidation of EuroSCORE II will be needed to identify calibration drift or clinical inconsistencies, which commonly emerge in clinical prediction models.

Mortality data in adult cardiac surgery for named surgeons: Retrospective examination of prospectively collected data on coronary artery surgery and aortic valve replacement

Abstract Objectives To present named surgeon mortality for isolated first time coronary artery surgery and aortic valve surgery. Design Retrospective analysis of prospectively collected data. Setting All NHS hospitals undertaking adult cardiac surgeryin north west England. Participants 25 consultant surgeons carrying out coronary arterysurgery and aortic valve replacement between April 2001 andMarch 2004. Main outcome measures Mortality for both operations accordingto surgeon. EuroSCORE to stratify patients into low and highrisk. Results 10 163 patients underwent surgery under 25 surgeons.The average number of patients per surgeon was 363 for coronaryartery surgery and 44 for aortic valve replacement. Seventeenper cent of the patients undergoing coronary artery surgeryand half of those undergoing aortic valve surgery were consideredhigh risk. The average mortality was 1.8% (range 0-3.8%) forcoronary surgery and 1.9% (0-12.5%) for aortic valve surgery.Mortality for all surgeons fell below 99% control limits ofthe national mean for both operations. Conclusions The presented mortality figures for the two cardiacoperations fell within accepted limits for all surgeons. Thedivision of outcomes according to low and high risk patientsis imperfect but may help to inform the public about the complexitiesof this type of analysis and prevent surgeons avoiding highrisk patents who may benefit from an operation.

The EuroSCORE risk stratification system in the current era: how accurate is it and what should be done if it is inaccurate?

2009;35:59-61 Eur J Cardiothorac Surg Bridgewater Cliff K. Choong, Paul Sergeant, Samer A.M. Nashef, Julian A. Smith and Ben how accurate is it and what should be done if it is inaccurate? Editorial comment: The EuroSCORE risk stratification system in the current era: This information is current as of August 28, 2011 http://ejcts.ctsnetjournals.org/cgi/content/full/35/1/59 located on the World Wide Web at: The online version of this article, along with updated information and services, is

Repair of post-infarct ventricular septal defect with or without coronary artery bypass grafting in the northwest of England: a 5-year multi-institutional experience.

OBJECTIVE To present the 5-year experience of the northwest of Englands surgical repair of post myocardial infarction (MI) ventricular septal defects (VSD). Our primary aim was to evaluate the effect of concomitant coronary artery bypass grafting (CABG) on mid-term survival and also to identify prognostic indicators. METHODS A multi-centre regional observational study involving clinical data from 65 consecutive patients who underwent post MI VSD repair in the northwest of England between April 1997 and March 2002. Both prospective and retrospective collection of preoperative, operative and postoperative information was performed. Patient follow-up was performed by linking their records to the National Strategic Tracing Service database. Multivariate logistic regression and Cox proportional hazards analyses were used to identify independent risk factors for poor prognosis. RESULTS Of the 65 patients included in the study, 42 (64.6%) underwent concomitant CABG with a median of two grafts. The majority of patients who had their coronary arteries grafted had multivessel disease (92.9%). Overall 30-day mortality was 23.1%. Predictors of poor prognosis included preoperative inotropes (P<0.001) and total occlusion of infarct related artery (P=0.03). The crude hazard ratio (HR) of mid-term mortality for concomitant CABG patients was 0.82 [95% confidence interval (CI) 0.38-1.78; P=0.62]. After adjustment for differences in patient and disease characteristics, the adjusted HR of mid-term mortality for concomitant CABG patients was 0.17 (95% CI 0.04-0.74; P=0.019). The adjusted freedom from death in the concomitant CABG patients at 30 days, 1, 2, and 4 years was 96.2%, 91.6%, 88.8%, and 82.8%, respectively, compared with 79.1%, 58.8%, 49.1%, and 32.2% for the non-concomitant CABG patients. CONCLUSION These data provide evidence that concomitant CABG is significantly beneficial to mid-term mortality rates. We recommend that patients who present with post MI VSD who have multivessel disease should be routinely revascularised.