Is the Parsonnet's score a good predictive score of mortality in adult cardiac surgery: assessment by a French multicentre study

Optimising bloodless cardiovascular surgery for Jehovah's Witnesses and beyond

Emerging evidence suggests surgical outcomes of patients undergoing cardiovascular surgery that refuse autologous transfusion is comparable to those who accept whole blood product transfusions. There are several methods that can be used to minimize blood loss during cardiovascular surgery. These methods can be categorised into pharmacological measures, including the use of erythropoietin, iron and tranexamic acid, surgical techniques, like the use of polysaccharide haemostat, and devices such as those used in acute normovolaemic haemodilution. More prospective studies with stricter protocols are required to assess surgical outcomes in bloodless cardiac surgery as well as further research into the long-term outcomes of bloodless cardiovascular surgery patients. This review summarizes current evidence on the use of pre-, intra-, and post-operative strategies aimed at the subset of patients who refuse blood transfusion, for example Jehovah's Witnesses.

Scoring Systems for Risk Stratification in Patients Undergoing Cardiac Surgery

Cardiac surgery is associated with significant mortality rates. Careful selection of surgical candidates is, therefore, vital to optimize morbidity and mortality outcomes. Risk scores can be used to inform this decision-making process. The European System for Cardiac Operative Risk Evaluation Score and the Society of Thoracic Surgeons score are among the most commonly used risk scores. There are many other scoring systems in existence; however, no perfect scoring system exists, therefore, additional research is needed as clinicians strive toward a more idealized risk stratification model. The purpose of this review is to discuss the advantages and limitations of some of the most commonly used risk stratification systems and use this to determine what an ideal scoring system might look like. This includes not only the generalizability of available scores but also their ease of use and predictive power.

Coronary artery bypass grafting in South Asian patients: Impact of gender

BACKGROUND

Outcomes following Coronary artery bypass grafting (GABG) vary between genders, with females having a higher postoperative mortality than males. Most of the studies are on Caucasian or mixed population and it is postulated that Asian population and in particular women have higher morbidity and mortality. In this study we have compared outcomes of elective CABG in men and women of South Asian origin in terms of morbidity and mortality.

METHODS

From January 2006 to December 2012, 1970 patients underwent isolated elective CABG at the Aga Khan University Hospital, Pakistan were selected. The prospectively collected data was analyzed retrospectively including univariate and multivariate analysis to find the association of morbidity and mortality.

RESULTS

Among the study patients 1664 (85%) were male and 306 (15%) female. Hypertension and diabetes were the most common comorbid conditions seen preoperatively in female patients. Atrial fibrillation and sepsis were the most common postop complications seen in females. In hospital mortality was 3.9% in female underwent CABG as against 0.6% in male. Multivariate analysis showed older age, renal failure, dyslipidemia and prolonged cross clamp time as predictors of postoperative morbidity. Multivariate analysis showed female gender, age and renal failure as predictors of in hospital mortality.

CONCLUSIONS

Female gender is an independent risk factor for postoperative mortality following CABG however, female gender is not found to be independent risk factor for morbidity. The trend of higher mortality in female patients was comparable to most studies done on Caucasian patients.

Does Parsonnet scoring model predict mortality following adult cardiac surgery in India?

Aims and Objectives:

To validate the Parsonnet scoring model to predict mortality following adult cardiac surgery in Indian scenario.

Materials and Methods:

A total of 889 consecutive patients undergoing adult cardiac surgery between January 2010 and April 2011 were included in the study. The Parsonnet score was determined for each patient and its predictive ability for in-hospital mortality was evaluated. The validation of Parsonnet score was performed for the total data and separately for the sub-groups coronary artery bypass grafting (CABG), valve surgery and combined procedures (CABG with valve surgery). The model calibration was performed using Hosmer–Lemeshow goodness of fit test and receiver operating characteristics (ROC) analysis for discrimination. Independent predictors of mortality were assessed from the variables used in the Parsonnet score by multivariate regression analysis.

Results:

The overall mortality was 6.3% (56 patients), 7.1% (34 patients) for CABG, 4.3% (16 patients) for valve surgery and 16.2% (6 patients) for combined procedures. The Hosmer–Lemeshow statistic was <0.05 for the total data and also within the sub-groups suggesting that the predicted outcome using Parsonnet score did not match the observed outcome. The area under the ROC curve for the total data was 0.699 (95% confidence interval 0.62–0.77) and when tested separately, it was 0.73 (0.64–0.81) for CABG, 0.79 (0.63–0.92) for valve surgery (good discriminatory ability) and only 0.55 (0.26–0.83) for combined procedures. The independent predictors of mortality determined for the total data were low ejection fraction (odds ratio [OR] - 1.7), preoperative intra-aortic balloon pump (OR - 10.7), combined procedures (OR - 5.1), dialysis dependency (OR - 23.4), and re-operation (OR - 9.4).

Conclusions:

The Parsonnet score yielded a good predictive value for valve surgeries, moderate predictive value for the total data and for CABG and poor predictive value for combined procedures.

Combination of European System for Cardiac Operative Risk Evaluation (EuroSCORE) and Cardiac Surgery Score (CASUS) to Improve Outcome Prediction in Cardiac Surgery

Background

We hypothesized that the combination of a preoperative and a postoperative scoring system would improve the accuracy of mortality prediction and therefore combined the preoperative ‘additive EuroSCORE‘ (European system for cardiac operative risk evaluation) with the postoperative ‘additive CASUS’ (Cardiac Surgery Score) to form the ‘modified CASUS’.

Material/Methods

We included all consecutive adult patients after cardiac surgery during January 2007 and December 2010 in our prospective study. Our single-centre study was conducted in a German general referral university hospital. The original additive and the ‘modified CASUS’ were tested using calibration and discrimination statistics. We compared the area under the curve (AUC) of the receiver characteristic curves (ROC) by DeLong’s method and calculated overall correct classification (OCC) values.

Results

The mean age among the total of 5207 patients was 67.2±10.9 years. Whilst the ICU mortality was 5.9% we observed a mean length of ICU stay of 4.6±7.0 days. Both models demonstrated excellent discriminatory power (mean AUC of ‘modified CASUS’: ≥0.929; ‘additive CASUS’: ≥0.920), with no significant differences according to DeLong. Neither model showed a significant p-value (<0.05) in calibration. We detected the best OCC during the 2^nd day (modified: 96.5%; original: 96.6%).

Conclusions

Our ‘additive’ and ‘modified’ CASUS are reasonable overall predictors. We could not detect any improvement in the accuracy of mortality prediction in cardiac surgery by combining a preoperative and a postoperative scoring system. A separate calculation of the two individual elements is therefore recommended.

Validation of Scoring Systems That Predict Outcomes in Patients With Coronary Artery Disease Undergoing Coronary Artery Bypass Grafting Surgery

Several risk stratification scores, based on angiographic or clinical parameters, have been developed to evaluate outcomes in patients with left main coronary artery disease (LMCAD) who undergo coronary artery bypass grafting (CABG). This study aims to validate the predictive ability of different risk scoring systems with regard to long-term outcomes after CABG. This single-center study retrospectively re-evaluated the Synergy Between PCI with TAXUS and Cardiac Surgery (SYNTAX) score; EuroSCORE; age, creatinine, and ejection fraction (ACEF) score; modified ACEF score; clinical SYNTAX; logistic clinical SYNTAX score (logistic CSS); and Parsonnet scores for 305 patients with LMCAD who underwent CABG. The endpoints were 5-year rate of all-cause death and major adverse cardio-cerebral events (MACCEs), including cardiovascular (CV) death, myocardial infarction (MI), and stroke and target vessel revascularization (TVR). Compared with the SYNTAX score, other scores were significantly higher in discriminative ability for all-cause death (SYNTAX vs others: P < 0.01). The EuroSCORE ≥6 showed significant outcome difference on all-cause death, CV death, MI, and MACCE (P < .01). Multivariate analysis indicated the SYNTAX score was a non-significant predictor for different outcomes. Adjusted multivariate analysis revealed that the EuroSCORE was the strongest predictor of all-cause death (hazard ratio[HR]: 1.17; P < 0.001), CV death (HR: 1.16; P < 0.001), and MACCE (HR: 1.09; P = 0.01). The ACEF score and logistic CSS were predictive factors for TVR (HR: 0.25, P = 0.03; HR: 0.85, P = 0.01). The EuroSCORE scoring system most accurately predicts all-cause death, CV death, and MACCE over 5 years, whereas low ACEF score and logistic CSS are independently associated with TVR over the 5-year period following CABG in patients with LMCAD undergoing CABG.

The influence of body mass index on outcomes in patients undergoing cardiac surgery: does the obesity paradox really exist?

Purpose

Obesity influences risk stratification in cardiac surgery in everyday practice. However, some studies have reported better outcomes in patients with a high body mass index (BMI): this is known as the obesity paradox. The aim of this study was to quantify the effect of diverse degrees of high BMI on clinical outcomes after cardiac surgery, and to assess the existence of an obesity paradox in our patients.

Methods

A total of 2,499 consecutive patients requiring all types of cardiac surgery with cardiopulmonary bypass between January 2004 and February 2009 were prospectively studied at our institution. Patients were divided into four groups based on BMI: normal weight (18.5–24.9 kg∙m⁻²; n = 523; 21.4%), overweight (25–29.9kg∙m⁻²; n = 1150; 47%), obese (≥30–≤34.9kg∙m⁻²; n = 624; 25.5%) and morbidly obese (≥35kg∙m⁻²; n = 152; 6.2%). Follow-up was performed in 2,379 patients during the first year.

Results

After adjusting for confounding factors, patients with higher BMI presented worse oxygenation and better nutritional status, reflected by lower PaO₂/FiO₂ at 24h and higher albumin levels 48h after admission respectively. Obese patients showed a higher risk for Perioperative Myocardial Infarction (OR: 1.768; 95% CI: 1.035–3.022; p = 0.037) and septicaemia (OR: 1.489; 95% CI: 1.282–1.997; p = 0.005). In-hospital mortality was 4.8% (n = 118) and 1-year mortality was 10.1% (n = 252). No differences were found regarding in-hospital mortality between BMI groups. The overweight group showed better 1-year survival than normal weight patients (91.2% vs. 87.6%; Log Rank: p = 0.029. HR: 1.496; 95% CI: 1.062–2.108; p = 0.021).

Conclusions

In our population, obesity increases Perioperative Myocardial Infarction and septicaemia after cardiac surgery, but does not influence in-hospital mortality. Although we found better 1-year survival in overweight patients, our results do not support any protective effect of obesity in patients undergoing cardiac surgery.

Preoperative diastolic function predicts the onset of left ventricular dysfunction following aortic valve replacement in high-risk patients with aortic stenosis

INTRODUCTION

Left ventricular (LV) dysfunction frequently occurs after cardiac surgery, requiring inotropic treatment and/or mechanical circulatory support. In this study, we aimed to identify clinical, surgical and echocardiographic factors that are associated with LV dysfunction during weaning from cardiopulmonary bypass (CPB) in high-risk patients undergoing valve replacement for aortic stenosis.

METHODS

Perioperative data were prospectively collected in 108 surgical candidates with an expected operative mortality >or=9%. All anesthetic and surgical techniques were standardized. Reduced LV systolic function was defined by an ejection fraction <40%. Diastolic function of the LV was assessed using standard Doppler-derived parameters, tissue Doppler Imaging (TDI) and transmitral flow propagation velocity (Vp).

RESULTS

Doppler-derived pulmonary flow indices and TDI could not be obtained in 14 patients. In the remaining 94 patients, poor systolic LV was documented in 14% (n = 12) and diastolic dysfunction in 84% of patients (n = 89), all of whom had Vp <50 cm/s. During weaning from CPB, 38 patients (40%) required inotropic and/or mechanical circulatory support. By multivariate regression analysis, we identified three independent predictors of LV systolic dysfunction: age (Odds ratio [OR] = 1.11; 95% confidence interval (CI), 1.01 to 1.22), aortic clamping time (OR = 1.04; 95% CI, 1.00 to 1.08) and Vp (OR = 0.65; 95% CI, 0.52 to 0.81). Among echocardiographic measurements, Vp was found to be superior in terms of prognostic value and reliability. The best cut-off value for Vp to predict LV dysfunction was 40 cm/s (sensitivity of 72% and specificity 94%). Patients who experienced LV dysfunction presented higher in-hospital mortality (18.4% vs. 3.6% in patients without LV dysfunction, P = 0.044) and an increased incidence of serious cardiac events (81.6 vs. 28.6%, P < 0.001).

CONCLUSIONS

This study provides the first evidence that, besides advanced age and prolonged myocardial ischemic time, LV diastolic dysfunction characterized by Vp <or= 40 cm/sec identifies patients who will require cardiovascular support following valve replacement for aortic stenosis.

Operative mortality in women and men undergoing coronary artery bypass grafting (from the California Coronary Artery Bypass Grafting Outcomes Reporting Program)

The comparative operative mortality (OM) in women and men undergoing isolated coronary artery bypass graft surgery (CABG) has not been clarified. Therefore, we evaluated factors related to OM in a large cohort of women and men undergoing isolated CABG. Results from 121 hospitals on patients undergoing isolated CABG in 2003 and 2004 were analyzed according to gender, including demographics, clinical characteristics, and surgical outcome. A total of 10,708 women and 29,669 men had isolated CABG in 2003 to 2004. Observed mortality in women was significantly higher than in men (4.60% vs 2.53%, p <0.0001). Although men had a higher prevalence of >3 diseased coronary arteries and left ventricular dysfunction, women were more likely to be older, diabetic, have stage 3 to 5 chronic kidney disease, chronic lung disease, and nonelective CABG. Women were less likely to receive an internal mammary artery graft. Multivariate analysis indicated that women were at higher risk for OM than men (odds ratio 1.61, 95% confidence interval 1.40 to 1.84). In conclusion, data from the large state-mandated CCORP indicate that women are at increased risk of OM after isolated CABG compared to men, despite adjustment for preoperative risk factors.

Risk stratification models for cardiac surgery

A wide variety of risk stratification systems have been developed to quantify the risk of cardiac surgery. Generally, the focus has been on mortality; however, more recently models have been developed that allow the preoperative prediction of the incidence of morbidity, including renal failure, infection, prolonged ventilation, and neurologic deficit. Many of these risk stratification models are developed from large databases of cardiac surgical patients. Patient and surgical factors that are present preoperatively are assessed for their predictive value for postoperative complications. Risk factors that are found to be significant are assigned a specific weight in the overall summation of risk. These models have been used as tools to compare surgeon's results, institutional outcomes, individual patient risk, and within quality improvement programs. This article will focus on the European System for Cardiac Operative Risk Evaluation, the Society of Thoracic Surgeons score, the Parsonnet score, Cleveland Clinic Model, the Bayes model, and the Northern New England Score.

Factors affecting postoperative morbidity and mortality in isolated coronary artery bypass graft surgery

PURPOSE

This study was conducted to investigate predictors of mortality before and after isolated coronary artery bypass grafting (CABG).

METHODS

Single-institutional data on risk factors and mortality were collected for 8890 patients who underwent isolated CABG by the same group of surgeons. The relationship between risk factors and outcome was assessed using univariate and multivariate analyses in two risk models: a preoperative model (model 1) and then a pre-, intra-, and postoperative model (model 2).

RESULTS

The mean age of the patients (25.4% women and 74.6% men) was 58.5 +/- 9.7 years. Fifty-five (0.6%) patients died after surgery. Hypercholesterolemia was the most common comorbidity factor (61.1%), followed by hypertension, a smoking habit, recent myocardial infarction (MI) <21 days, and diabetes. Postoperative tamponade, graft occlusion, and MI (0.01%) were the least common complications. The patients spent 39.7 +/- 33.9 h in the intensive care unit (ICU) postoperatively. Patients were followed up for a minimum of 30 days. The multivariate analysis of our preoperative risk model revealed that the best predictors of operative mortality were a history of diabetes, hypertension, previous CABG, the presence of angina, arrhythmia, Canadian Cardiovascular Society Classification (CCS) of grade III or IV, ejection fraction (EF) < or =30%, three-vessel disease, and left main disease.

CONCLUSION

After surgery, and with the inclusion of all the pre-, intra-, and postoperative variables into model two, the following were revealed to be prognostic factors for in-hospital mortality: a history of diabetes, hypertension, the presence of angina, CCS grades III or IV, EF -30%, absence of internal mammary artery (IMA) use, prolonged cardiopulmonary bypass (CPB) time, and prolonged ICU stay.

Preoperative B-type natriuretic peptide is as independent predictor of ventricular dysfunction and mortality after primary coronary artery bypass grafting

OBJECTIVE

Elevated B-type natriuretic peptide is associated with increased morbidity and mortality in ambulatory patients with congestive heart failure or acute coronary syndromes. Its utility in predicting adverse cardiac surgical outcomes is less certain. We hypothesized that preoperative plasma B-type natriuretic peptide would independently predict in-hospital postoperative ventricular dysfunction, hospital stay, and up to 5-year mortality after primary coronary artery bypass grafting.

METHODS

This is a prospective, longitudinal study of 1023 patients at two institutions undergoing primary coronary artery bypass grafting with cardiopulmonary bypass. Ventricular dysfunction was defined as requirement for at least two inotropes or new intra-aortic balloon pump or ventricular assist device support after coronary artery bypass grafting. Multivariable analyses assessed independent roles of preoperative B-type natriuretic peptide in predicting postoperative ventricular dysfunction, hospital stay, and 5-year all-cause mortality.

RESULTS

Preoperative plasma B-type natriuretic peptide concentration predicted ventricular dysfunction, hospital stay, and mortality in univariate and multivariable analyses. Logistic regression demonstrated preoperative B-type natriuretic peptide to independently predict ventricular dysfunction (odds ratio 1.92, 95% confidence interval 1.12-3.29, P = .018), after adjustment for preoperative left ventricular ejection fraction, congestive heart failure severity, and other clinical predictors. Multivariable Cox proportional hazards models showed preoperative B-type natriuretic peptide to independently predict hospital stay (hazard ratio 1.42, 95% confidence interval 1.18-1.72, P = .0002) and mortality (hazard ratio 1.89, 95% confidence interval 1.08-3.33, P = .026).

CONCLUSION

Preoperative plasma B-type natriuretic peptide independently predicted in-hospital ventricular dysfunction, hospital stay, and up to 5-year all-cause mortality after primary coronary artery bypass grafting.

Severity of chronic kidney disease as a risk factor for operative mortality in nonemergent patients in the California coronary artery bypass graft surgery outcomes reporting program

Guidelines published by the National Kidney Foundation in 2002 categorize renal failure into 5 stages of increasing severity. The relation of this classification to risk stratification for operative mortality in patients with nonemergent coronary artery bypass grafting (CABG) has not been clarified. We examined the effect of chronic kidney disease (CKD) severity on CABG operative mortality in patients with nonemergent CABG. Data reporting to the California CABG outcomes reporting program is mandated in California. Data from 121 hospitals on patients undergoing CABG in 2003 and 2004 were analyzed, including clinical characteristics, CKD stage, and operative mortality. CKD stage 1 and 2 were combined to form the reference group because data on urinary markers of renal failure were not available. Excluding patients with emergent or salvage acuity for CABG, 37,735 isolated CABGs were performed. Of these, 27,132 patients (71.9%) had glomerular filtration rate (GFR)>or=60 ml/min/1.73 m2; 8,861 (23.5%) had stage 3 CKD (GFR 30 to 59); 669 (1.8%) had stage 4 CKD (GFR 15 to 29); and 1,073 (2.8%) had stage 5 CKD (GFR<15 or on dialysis). In separate multivariate analyses, GFR and CKD stage were each significantly and independently associated with operative mortality (both p<0.0001). Operative mortality increased significantly with each stage of CKD (all p<0.01). Compared with the reference group, stage 3, (odds ratio [OR] 1.18, p=0.0374), stage 4 (OR 2.23, p<0.0001), and stage 5 (OR 4.39, p<0.0001) had increasingly higher operative mortality. In conclusion, CKD stage based on National Kidney Foundation guidelines is an important predictor in risk stratification for operative mortality in patients undergoing nonemergent CABG.

24-Hour In-hospital Mortality Predictions in Coronary Artery Bypass Grafting Patients

BACKGROUND

The purpose of this study was to determine the factors that can help predict risk of mortality in the first 24 h of coronary artery bypass grafting (CABG), because mortality within a few hours of surgery is a disastrous event for surgeons and the patient's family.

METHODS

The study population consisted of 120 in-hospital mortality cases (1.07%) from 11,183 patients who underwent CABG from February 2002 to February 2006 by the same group of surgeons in a referral center. One group consisted of 40/120 (about 33.3%) patients who died during the first 24 h after surgery. The second group consisted of 80/120 patients (66.7%) who died between the 2(nd) and 30(th) day postoperatively. A set of data was gathered from the surgery database of the hospital and analyzed in a univariate model.

RESULTS

Among the studied variables, only the following factors proved to be significant: previous percutaneous transluminal coronary angioplasty (PTCA), previous cerebrovascular accident (CVA), cardiopulmonary bypass (CBP) time, and postoperative atrial fibrillation (AF) (p </=0.05).

CONCLUSIONS

This study revealed that influencing factors in 24-h in-hospital mortality are previous PTCA, previous CVA, CBP time, and postoperative AF. It is interesting that influencing factors in global 30-day hospital mortality such as body mass index, diabetes mellitus, preoperative arrhythmia, ejection fraction, history of previous CABG and resuscitation, or catastrophic states like poor runoff coronary vessels, triple vessel disease or associated procedures like valve surgery were not significant in the first 24-h mortality when comparing with in-hospital mortality in this study.

[Operative risk of heart valve surgery after 80 years]

The continuous prolongation of life expectancy in developed nations and the progress made in the surgical treatment of valvulopathy have substantially increased the number of octogenarians undergoing heart valve surgery with extracorporeal circulation. Most of them have calcified aortic stenosis and the valve is replaced with a bioprosthesis. At these ages, mitral valve disease--usually insufficiency--is predominantly treated by repair rather than valve replacement. In both cases, the etiology is primarily degenerative. In addition, an ever-increasing percentage of these patients require replacement of deteriorated bioprostheses. These octogenarians are exposed to surgical risk estimated to be about 9-10%, i.e. 2-3 times higher than that of patients under 70 years of age, and even higher when surgery is a reintervention. Furthermore, morbidity affecting approximately an additional third of those undergoing surgery must be added to this mortality. Therefore, only half of the patients have uncomplicated surgical outcomes. Age is not the only factor enhancing the risk, which is also linked to comorbidities, preoperative functional class, stage of the evolving valvulopathy, and association of coronary artery disease. Predictive scores (Parsonnet, EuroScore) have been devised to evaluate the surgical risk to which these patients are subjected. Rigorous selection of patients with severe valvulopathy should enable potential candidates, willing to undergo an intervention, to be provided with indications for surgery sufficiently early so as to not enhance the risk by intervening too late.

Validation of the 2000 Bernstein-Parsonnet Score Versus the EuroSCORE as a Prognostic Tool in Cardiac Surgery

BACKGROUND

Intradepartmental and interdepartmental benchmarking requires scoring systems with reliability (calibration) and stability over the complete spectrum of periprocedural risk. The aim of this single-center study was to assess the performance of the 2000 Bernstein-Parsonnet risk stratification model in cardiac surgery, by itself and against the EuroSCORE.

METHODS

A prospective observational design was used. The study group consisted of 1,639 consecutive patients of mean age 64.6 +/- 12.04 years who underwent elective or emergency cardiac surgery from January 2003 to June 2004. The probabilities of hospital death were estimated with the 2000 Bernstein-Parsonnet and EuroSCORE algorithms. The correlation of predicted and observed mortality was compared between the two models, and score validity was assessed by calculating the area under the receiver operating characteristic (ROC) curve.

RESULTS

The patients were stratified into five risk groups according to their scores in the two models. For the 2000 Bernstein-Parsonnet model, findings were as follows: score 0-10: predicted mortality 0%-2.2%, observed mortality 0.6%; score 10.5-20: predicted 2.3%-4.7%, observed 2.3%; score 20.5-30: predicted 4.8%-10%, observed 6.7%; score 30.5-40: predicted 10.1%-23%, observed 11.5%; and score greater than 40: predicted 23.1%-80%, observed 29.9%. For the EuroSCORE, findings were as follows: score 0%-2%: predicted mortality 1.1%, observed mortality 0.6%; score 3%-5%: predicted 2.1%, observed 3.0%; score 6%-8%: predicted 4.1%, observed 3.5%; score 9-11: predicted 7.6%, observed 6.6.%; and score greater than 12: predicted 13.8%, observed 14.0%. There was good agreement between the observed and expected number of deaths, with both models. The area under the ROC curve was higher for the Bernstein-Parsonnet model (0.83, odds ratio [OR] 2.01, 95% confidence interval [CI] 1.75-2.31, p < 0.0001) than for the EuroSCORE (0.73, OR 1.05, 95% CI 1.04-1.07, p < 0.001).

CONCLUSIONS

The 2000 Bernstein-Parsonnet model is a simple, objective system for the estimation of hospital mortality in patients undergoing cardiac surgery, with slightly higher calibration and discrimination than the EuroSCORE additive model.

Comparison of 19 pre-operative risk stratification models in open-heart surgery

AIMS

To compare 19 risk score algorithms with regard to their validity to predict 30-day and 1-year mortality after cardiac surgery.

METHODS AND RESULTS

Risk factors for patients undergoing heart surgery between 1996 and 2001 at a single centre were prospectively collected. Receiver operating characteristics (ROC) curves were used to describe the performance and accuracy. Survival at 1 year and cause of death were obtained in all cases. The study included 6222 cardiac surgical procedures. Actual mortality was 2.9% at 30 days and 6.1% at 1 year. Discriminatory power for 30-day and 1-year mortality in cardiac surgery was highest for logistic (0.84 and 0.77) and additive (0.84 and 0.77) European System for Cardiac Operative Risk Evaluation (EuroSCORE) algorithms, followed by Cleveland Clinic (0.82 and 0.76) and Magovern (0.82 and 0.76) scoring systems. None of the other 15 risk algorithms had a significantly better discriminatory power than these four. In coronary artery bypass grafting (CABG)-only surgery, EuroSCORE followed by New York State (NYS) and Cleveland Clinic risk score showed the highest discriminatory power for 30-day and 1-year mortality.

CONCLUSION

EuroSCORE, Cleveland Clinic, and Magovern risk algorithms showed superior performance and accuracy in open-heart surgery, and EuroSCORE, NYS, and Cleveland Clinic in CABG-only surgery. Although the models were originally designed to predict early mortality, the 1-year mortality prediction was also reasonably accurate.

Midterm Results of Off-Pump Coronary Artery Bypass Surgery in 136 Patients: An Angiographic Control Study

BACKGROUND

Off-pump coronary artery bypass surgery may provide an alternative form of surgical revascularization by avoiding the complications of cardiopulmonary bypass (CPB). This study summarizes the midterm results of 136 off-pump bypass surgery patients.

METHODS

Between January 2000 and March 2002, out of 178 surgical myocardial revascularizations, 136 (76.4%) were off-pump bypass surgery. Complete revascularization was done and especially arterial grafts were used. All patients were followed clinically and with treadmill test for 2 years. Average control angiography was performed at the end of 2-year follow-up.

RESULTS

Of all the patients, 56.7% were male and the mean age of the patients was 63.6 +/- 7.4 years. A total of 481 anastomoses were performed-136 (28.27%) to the left anterior descending artery (LAD), 135 (28.07%) to the circumflex coronary artery (Cx) branches, 102 (21.20%) to the right coronary artery (RCA), 108 (22.46%) to the Di. The mean graft number was 3.46. We used 96.6% of patients' left internal mammarian artery (LITA), 29.2% radial artery (RA), 4.4% right internal thoracic artery (RITA), and 100% saphenous vein. There were ischemic changes within 12 patients. All ischemic changes came back to normal within 4 and 18 hours, postoperatively. Mean extubation time was 5.36 +/- 2.23 hours, mean stay in intensive care unit was 17.53 +/- 3.15 hours, mean hospital stay was 5.03 +/- 1.29 days. The LITA patency was 99.25%, RA patency was 97.84%, RITA patency was 100%, and saphenous vein patency was 91.79% with control angiography.

CONCLUSION

Off-pump coronary artery bypass graft (CABG) is efficient procedure with lower index of mortality, morbidity, ICU stay, hospital stay, good wound healing, early socialization, and results in lower costs.

Off-pump coronary artery bypass grafting decreases morbidity and mortality in a selected group of high-risk patients

BACKGROUND

The ideal indication for off-pump coronary artery bypass grafting (OPCABG) has yet to be defined. High-risk surgical patients may benefit the most when cardiopulmonary bypass (CPB), aortic cross clamping, and cardioplegic arrest are avoided. The aim of this study was to determine whether off-pump coronary artery bypass grafting might decrease the operative morbidity and mortality in a select group of high-risk patients with multivessel coronary artery disease.

METHODS

Utilizing a Parsonnet risk stratification model we analyzed prospectively collected data on a cohort of high-risk coronary artery disease patients, which were operated on with beating-heart technology by the same group of surgeons in a tertiary care university medical center. High-risk patients were defined as those with a Parsonnet score of 15 or greater.

RESULTS

Fifty-seven multivessel disease OPCABG patients (over a period of 2 years) had markedly increased Parsonnet scores (24.3 +/- 10.6). The average ejection fraction of the patients was 42% (+/-12.3) and their age ranged from 52 to 85 years (mean 70.6 +/- 10.4, 26% women). Unstable angina was present in 42 patients (74%) and 10 patients underwent OPCABG within 24 hours of the occurrence of acute myocardial infarction. In addition to severe coronary artery disease 32% of the patients presented with congestive heart failure, insulin-dependent diabetes (18%), renal failure (22%), peripheral vascular disease (31%), pulmonary disease (18%), and neurologic disorders (14%). An average of 2.6 +/- 0.9 grafts/patient were performed and the posterior descending artery or marginal branches of the circumflex artery or both were grafted in 90%. The 30-day mortality rate was 3.5% (n = 2).

CONCLUSIONS

OPCABG can be performed with a reasonable low morbidity and mortality in this select group of high-risk patients. OPCABG is a reasonable, and might even be preferable, operative strategy in this high-risk group of patients.

Revascularization during acute myocardial infarction: risks and benefits revisited

BACKGROUND

Indication for immediate revascularization during acute myocardial infarction (MI) is debated. Drug-resistant crescendo angina, as well as hemodynamic compromise, however, often requires acute operation. In this study the differential risks of acute coronary artery bypass grafting with and without MI were stratified.

METHODS

Five hundred eighteen patients undergoing isolated coronary artery bypass grafting were investigated. Thirty-nine patients underwent acute revascularization because of enzyme-proven or electrocardiogram-proven MI accompanied by crescendo angina, hemodynamic compromise, or both. They were compared with 33 emergent, 63 urgent, and 383 elective patients without MI. Preoperative risk factors for early mortality and necessity of continuous venovenous hemofiltration were analyzed by means of logistical regression analysis. Perioperative data were compared.

RESULTS

Early mortality of the MI cohort was 15.4%, in contrast to 15.2% in emergent, none in urgent, and 2.1% in elective patients. Left internal thoracic artery was used in 87% of MI, 97% of emergent, 94% of urgent, and 97% of elective patients. Intraaortic balloon pump was necessary in 50% of MI patients, 27% of emergent, 6.3% of urgent, and 3.1% of elective cases. Continuous venovenous hemofiltration was performed in 29% of MI patients, 15% of emergent, 4.9% of urgent, and 3.4% of elective patients. Hemodynamic instability significantly increased the odds ratio for early mortality and continuous venovenous hemofiltration.

CONCLUSIONS

Patients undergoing acute revascularization carried an elevated risk to die early notwithstanding the presence or absence of acute MI. Liberal use of left internal thoracic artery grafts was not detrimental in acute patients whereas liberal use of intraaortic balloon pump was beneficial. In almost 30% of MI patients, continuous venovenous hemofiltration was not necessary, implying a severely impaired perioperative hemodynamic condition. Immediate revascularization in the presence of acute MI is therefore indicated although it may be addressed as a separate high-risk group.

Risk stratification in acute type A dissection: proposition for a new scoring system

BACKGROUND

The aim of this study was to develop a scoring system for operative mortality of patients with acute type A aortic dissection.

METHODS

Between 1974 and 1999, a total of 252 patients were operated on for an acute type A aortic dissection. We reviewed retrospectively preoperative and intraoperative records to conduct an analysis of risk factors associated with surgery. Multivariate analysis was used to predict operative mortality and to provide a preoperative risk profile of each individual patient that could be used for future patients.

RESULTS

Operative mortality was 25.0% (n = 63). A logistic regression model with three explanatory variables to predict operative death showed a good fit: the risk factors associated with operative mortality were preoperative cardiopulmonary resuscitation (p = 0.0013, odds ratio = 15.7) and iatrogenic dissection (p = 0.0014, odds ratio = 9.8). Drained pericardial tamponade (p = 0.0386, odds ratio = 0.12) appeared to be a protective factor associated with decreased mortality.

CONCLUSIONS

Because existing scoring systems do not fit this pathologic condition, we propose the use of this Antonius Dissection Scoring System, based on the logistic regression model, to predict the chances of operative mortality for each patient before operation. The survival of patients with concomittant pericardial tamponade may benefit from pericardial drainage.

Risk stratification analysis of operative mortality in coronary artery bypass surgery

OBJECTIVE

We assessed the operative mortality of coronary artery bypass grafting (CABG) surgery using risk stratification.

METHODS

In 294 consecutive patients who underwent CABG with or without concomitant surgery from August 1994 to December 1999, we compared operative mortality calculated conventionally and by risk stratification. Scores for each patient were calculated using the Parsonnet additive model and stratified based on the probability of operative mortality.

RESULTS

Overall crude hospital mortality was 4.8%-4.0% among patients younger than 80 years and 14% among those 80 years of age or older (p = 0.0692). Hospital mortality was 12% in urgent/emergency surgery, and 1.5% in elective surgery (p < 0.0002), and 4.5% in CABG alone and 7.4% in CABG with concomitant surgery (p = 0.3763), and 25% in patients receiving vein grafts only and 3.0% in those receiving at least 1 artery graft (p = 0.0003). Overall patient distribution was 32% good, 20% fair, 20% poor, 11% high-risk, and 16% extremely high-risk. Predicted mortality was 2.2% for patients who were a good risk, 6.7% for fair-risk, 12% for poor-risk, 16% for high-risk, and 25% for extremely high-risk patients. Actual operative mortality was 1.0% for good-risk, 0% for fair-risk, 3.4% for poor-risk, 6.3% for high-risk, and 18% for extremely high-risk patients, making actual mortality significantly lower than that predicted.

CONCLUSION

Comparing predicted mortality and actual mortality enabled us to objectively calculate operative results and assess operative quality.

Risk stratification in heart surgery: comparison of six score systems

OBJECTIVE

Risk scores have become an important tool in patient assessment, as age, severity of heart disease, and comorbidity in patients undergoing heart surgery have considerably increased. Various risk scores have been developed to predict mortality after heart surgery. However, there are significant differences between scores with regard to score design and the initial patient population on which score development was based. It was the purpose of our study to compare six commonly used risk scores with regard to their validity in our patient population.

METHODS

Between September 1, 1998 and February 28, 1999, all adult patients undergoing heart surgery with cardiopulmonary bypass in our institution were preoperatively scored using the initial Parsonnet, Cleveland Clinic, French, Euro, Pons, and Ontario Province Risk (OPR) scores. Postoperatively, we registered 30-day mortality, use of mechanical assist devices, renal failure requiring hemodialysis or hemofiltration, stroke, myocardial infarction, and duration of ventilation and intensive care stay. Score validity was assessed by calculating the area under the ROC curve. Odds ratios were calculated to investigate the predictive relevance of risk factors.

RESULTS

Follow-up was able to be completed in 504 prospectively scored patients. Receiver operating characteristics (ROC) curve analysis for mortality showed the best predictive value for the Euro score. Predictive values for morbidity were considerably lower than predictive values for mortality in all of the investigated score systems. For most risk factors, odds ratios for mortality were substantially different from ratios for morbidity.

CONCLUSIONS

Among the investigated scores, the Euro score yielded the highest predictive value in our patient population. For most risk factors, predictive values for morbidity were substantially different from predictive values for mortality. Therefore, development of specific morbidity risk scores may improve prediction of outcome and hospital cost. Due to the heterogeneity of morbidity events, future score systems may have to generate separate predictions for mortality and major morbidity events.