EuroSCORE Predicts Intensive Care Unit Stay and Costs of Open Heart Surgery

High-risk aortic valve replacement: are the outcomes as bad as predicted?

BACKGROUND

Percutaneous aortic valve replacement (PAVR) trials are ongoing in patients with an elevated European System for Cardiac Operative Risk Evaluation (EuroSCOREs), patients believed to have high mortality rates and poor long-term prognoses with valve replacement surgery. It is, however, uncertain that the EuroSCORE model is well calibrated for such high-risk AVR patients. We evaluated EuroSCORE prediction vs a single institution's surgical results in this target population.

METHODS

From January 1996 through March 2006, 731 patients with EuroSCOREs of 7 or higher underwent isolated AVR. In this cohort, 313 (42.8%) were septuagenarians, 322 (44.0%) were octogenarians or nonagenarians, 233 (31.9%) had had previous cardiac procedures, 237 (32.4%) had atheromatous aortas, and 127 (17.4%) had cerebrovascular disease. A minimally invasive approach was used in 469 (64.2%). Data collection was prospective. Long-term survival was computed from the Social Security Death Benefit Index.

RESULTS

The mean EuroSCORE was 9.7 (median, 10), and the mean logistic EuroSCORE was 17.2%. Actual hospital mortality was 7.8% (57 of 731). Multivariate analysis showed ejection fraction of less than 0.30 (p = 0.002; odds ratio [OR], 3.13), chronic obstructive pulmonary disease (p = 0.019; OR, 2.14), and peripheral vascular disease (p = 0.048; OR, 2.13) were significant predictors of hospital mortality. Complication(s) occurred in 73 patients (9.9%). Freedom from all-cause death (including hospital mortality) was 72.4% at 5 years (n = 152). Age (p < 0.001), previous cardiac operations (p < 0.014; OR, 1.51), renal failure (p < 0.002; OR, 2.37), and chronic obstructive pulmonary disease (p < 0.007; OR, 1.30) were predictors of worse survival.

CONCLUSIONS

Logistic EuroSCORE greatly overpredicts mortality in these patients. Five-year survival is good, unlike suggestions from earlier EuroSCORE analyses. This raises concern about unknown long-term percutaneous prosthesis function. Clinical trials for these patients must include randomized surgical controls and have long-term end points.

Triclosan-coated sutures for the reduction of sternal wound infections: economic considerations

BACKGROUND

Sternal wound infections are a major complication after cardiac surgery in terms of morbidity and cost increase. To decrease the incidence of infection, we evaluated triclosan-coated sutures for the closure of the sternal incision, as it is known that most of the surgical site infections are related to the incision site.

METHODS

From May to December 2005, a total of 479 patients underwent a cardiac surgical procedure. From those, 103 patients were closed with triclosan-coated suture material (cost per patient $30 [in United States dollars]), whereas the remaining 376 patients had their incision closed with noncoated sutures (cost per patient $21).

RESULTS

During the study period, 24 patients had superficial (n = 10) or deep (n = 14) sternal wound infections (cost per patient $11,200). All those patients were closed with conventional suture material. In the triclosan group, no wound infection or dehiscence was observed during hospital stay and follow-up visits.

CONCLUSIONS

Triclosan-coated sutures might be valuable in the reduction of sternal wound infections and avoid the suture being a risk factor for surgical site infections. The increased cost of the coated suture material has to be weighed against the enormous cost of sternal wound infections caused directly by the cost of care as well as indirectly through the loss of economic productivity.

A comparation of coronary artery bypass grafting with and without cardiopulmonary bypass in EuroSCORE high risk patients

Angiotensin converting enzyme (ACE) and nitric oxide (NO) have been suggested to be in - The objective of this study is to compare outcomes of coronary artery bypass grafting (CABG) in high-risk patients performed with- (ONCAB) and without -(OPCAB) use of cardiopulmonary bypass. From October 2001 till October 2005, 210 high-risk patients classified according to European System for Cardiac Operative Risk Evaluation (EuroSCORE) (score =or> 5) underwent CABG in Cardiovascular Clinic, University Clinical Centre Tuzla, Bosnia and Herzegovina. 138 patients operated as OPCAB were compared to 72 patients operated as ONCAB. All data were entered in a patient database (DATACOR) and analyzed in SPSS. OPCAB patients received insignificantly less number of grafts than those treated by ONCAB (3,0 vs. 3,2) (p=0,071). Stroke was significantly more common in ONCAB group (2,9 vs. 11,1%) (p=0,034) while the incidence of other postoperative complications and mortality were similar. The ventilation time (4,3 vs. 6,7 hours) (p=0,007), retransfusion volume (392,7 vs. 633,7 ml) (p=0,041) and hospital stay (8,2 vs. 10,1 days) (p=0,031) was significantly less in OPCAB group. OPCAB is safe and effective in treatment of high-risk patients. Avoidance of cardiopulmonary bypass is associated with reduced incidence of neurologic complications, lower intubation time, retransfusion rate and shorter hospital stay, and in our experience the preferred operative method in such patients.

Valor predictivo del modelo EuroSCORE en la cirugía cardíaca de nuestro centro

OBJECTIVE

The use of risk prediction models in cardiac surgery makes it possible to compare and evaluate health care quality between different institutions in countries. This study aimed to assess the performance of the European System for Cardiac Operative Risk Evaluation (EuroSCORE) model in estimating the risk of mortality of cardiac surgery patients of our hospital.

PATIENTS AND METHODS

The additive and logistic EuroSCORE models were applied to all patients who underwent cardiac surgery with extracorporeal circulation from the time the cardiac surgery unit was opened in our center in November 2002 until February 2006. All data were obtained prospectively when the patients were admitted to the Intensive Care Unit. Mortality observed was compared with that estimated in the following subgroups: global cardiac surgery, isolated coronary surgery, isolated valvular surgery, combined valvular and coronary surgery and thoracic aorta surgery. Model discrimination was tested by determining the area under the receiver operating characteristic (ROC) curve.

RESULTS

We studied 1,053 patients who had several differences with the EuroScore model population. Overall observed mortality was 2.2% (95% CI 1.2 - 3.1). The EuroSCORE models overestimated mortality (additive predicted 5%, logistic predicted 4.6%). Mortality of coronary bypass graft surgery was 1.2% and both EuroSCORE models overestimated it. Discriminative power of both models was good with an Area under ROC curve for both models of 0.78 and 0.79.

CONCLUSIONS

The use of both EuroSCORE models overestimated overall observed mortality and that of the different surgical subgroups of cardiac surgery performed in our institution.

Risk adjusted resource utilization for AMI patients treated in Japanese hospitals

Though risk adjustment is necessary in order to make equitable comparisons of resource utilization in the treatment of acute myocardial infarction patients, there is little in the literature that can be practically applied without access to clinical records or specialized registries. The aim of this study is to show that effective models of resource utilization can be developed based on administrative data, and to demonstrate a practical application of the same models by comparing the risk-adjusted performance of the hospitals in our dataset. The study sample included 1748 AMI cases discharged from 10 large, private teaching hospitals in Japan, between 10 April 2001 and 30 June 2004. Explanatory variables included procedures (CABG and PCI), length of stay, outcome, patient demographics, diagnosis and comorbidity status. Multiple linear regression models constructed for the study were able to account for 66.5, 27.7, and 58.4% of observed variation in total charges, length of stay and charges per day, respectively. The performance of models constructed for this study was comparable to or better than performance reported by other studies that made use of explanatory variables extracted from clinical data. The use of administrative data in risk adjustment makes broad scale application of risk adjustment feasible.

Open-heart surgery in patients with liver cirrhosis: indications, risk factors, and clinical outcomes

BACKGROUND

Because of recent advances in cardiopulmonary bypass (CPB) surgery, there are broadened indications to approach patients with a high operative risk. Meanwhile, there is an increasing number of patients with severe liver dysfunction subjected to open-heart surgery. This retrospective study was designed to evaluate the operative indications and clinical outcomes in patients with liver cirrhosis (LC) undergoing open-heart surgery. In addition, determinants influencing their prognosis were assessed.

PATIENTS AND METHODS

Between May 1996 and June 2005, 24 patients with LC underwent CPB open-heart surgery in our institution. The preoperative severity of the LC was determined according to the Child-Pugh classification. Their perioperative data were analyzed. Several perioperative factors were compared by multivariate logistic regression analysis between survivors and nonsurvivors to determine possible risk factors contributing to mortality.

RESULTS

There were 14 females and 10 males. Their age ranged from 36 to 72 (mean 53 +/- 13) years. Seventeen cases were classified as having Child-Pugh class A LC, 6 as having Child-Pugh class B, and 1 as having Child-Pugh class C LC. All patients underwent CPB surgery. The mean operation time and the cross-clamp time were 160 +/- 53 and 90 +/- 42 min, respectively. During the first 24 h after the operation, the mean chest tube output was 1,080 +/- 320 ml. The mean duration of mechanical ventilation was 32 +/- 22 h, and the mean intensive care unit stay was 11 +/- 8 days. Sixty-six percent of the patients experienced significant morbidity. Fifty-three percent of the patients with Child-Pugh class A LC and 100% of those with Child-Pugh class B and C LC suffered postoperative complications. The overall mortality rate was 25%. The postoperative mortality rates of the patients with Child-Pugh class A, B, and C LC were 6, 67, and 100%, respectively. Preoperative serum total bilirubin and cholinesterase levels and EuroSCORE (European System for Cardiac Operative Risk Evaluation) values along with CPB time were identified as the important predictors to differentiate between survivors and nonsurvivors by multivariate logistic regression analysis.

CONCLUSIONS

The Child-Pugh class is associated with hepatic decompensation and mortality after open-heart CPB surgery in patients with LC. Such surgery can be performed safely in patients with a Child-Pugh class A LC. But cardiac interventions using CPB in patients with more advanced LC are associated with high mortality and morbidity rates. The preoperative total plasma bilirubin and cholinesterase concentrations as well as the EuroSCORE along with the CPB time are identified as statistically significant predictors of mortality after open-heart surgery in patients with LC. Our findings indicate that patients with chronic liver disease scheduled for open-heart surgery should be carefully evaluated before the operation and that the CPB duration should be as short as possible.

EuroSCORE as a predictor of death and myocardial infarction after unprotected left main coronary stenting

This study aimed to identify the independent predictors of death and myocardial infarction (MI) after unprotected left main coronary artery stenting with bare metal (n = 148) or sirolimus-eluting (n = 176) stents between January 2000 and March 2005. To identify independent predictors of death and nonfatal MI, all available parameters were evaluated. Systemic surgical risk stratification systems such as the EuroSCORE and Parsonnet score were included in the analysis. Clinical information at 9 months was available in 98% of patients (median follow-up 26.3 months). During this period, death/MI occurred in 42 patients (13%). Of the 5 deaths, 4 were related to cardiac and 1 to noncardiac causes. By multivariate Cox regression analysis, a high EuroSCORE (> or =6; hazard ratio 3.4, 95% confidence interval 1.2 to 9.6, p = 0.023), number of stents used (hazard ratio 1.8, 95% confidence interval 1.0 to 3.1, p = 0.042), and treatment with a glycoprotein IIb/IIIa inhibitor (hazard ratio 8.6, 95% confidence interval 2.7 to 27.4, p <0.001) were independent predictors of death/MI. Areas under the receiver-operating characteristic curve of EuroSCORE and number of stents were 0.61 (95% confidence interval 0.52 to 0.70, p = 0.023) and 0.61 (95% confidence interval 0.51 to 0.70, p = 0.028), respectively. In conclusion, high surgical risk estimated by systemic risk stratification of the EuroSCORE appears to be associated with unfavorable outcomes of unprotected left main coronary artery stenting.

EuroSCORE: Useful in Directing Preoperative Intra-Aortic Balloon Pump Placement in Cardiac Surgery?

BACKGROUND

The placement of preoperative intra-aortic balloon pumps (IABP) in high-risk patients has been described, although controversy remains regarding the appropriate selection of these patients. The EuroSCORE is a proven predictor of operative mortality for coronary artery bypass surgery (CABG). Our objective was to assess whether patients with a preoperative IABP had a 30-day mortality consistent with their predicted mortality.

METHODS

Sixty-sis patients who had had an IABP sited while undergoing CABG were retrospectively identified. The additive EuroSCORE was calculated with omission of the IABP preoperative placement score of 3 points. Patients with a EuroSCORE <5 were considered low risk, and those > or = m5 as high risk.

RESULTS

High-risk patients with preoperative IABP placement had a significantly lower mortality (1/16, 6.25%) than predicted. The predicted versus actual mortality was 12.6% versus 6.25%.

CONCLUSION

Correct identification of appropriate patients who would benefit from pre-emptive placement of IABP could potentially be performed using the EuroSCORE.

Risk factor identification and mortality prediction in cardiac surgery using artificial neural networks

OBJECTIVE

The artificial neural network model is a nonlinear technology useful for complex pattern recognition problems. This study aimed to develop a method to select risk variables and predict mortality after cardiac surgery by using artificial neural networks.

METHODS

Prospectively collected data from 18,362 patients undergoing cardiac surgery at 128 European institutions in 1995 (the European System for Cardiac Operative Risk Evaluation database) were used. Models to predict the operative mortality were constructed using artificial neural networks. For calibration a sixfold cross-validation technique was used, and for testing a fourfold cross-testing was performed. Risk variables were ranked and minimized in number by calibrated artificial neural networks. Mortality prediction with 95% confidence limits for each patient was obtained by the bootstrap technique. The area under the receiver operating characteristics curve was used as a quantitative measure of the ability to distinguish between survivors and nonsurvivors. Subgroup analysis of surgical operation categories was performed. The results were compared with those from logistic European System for Cardiac Operative Risk Evaluation analysis.

RESULTS

The operative mortality was 4.9%. Artificial neural networks selected 34 of the total 72 risk variables as relevant for mortality prediction. The receiver operating characteristics area for artificial neural networks (0.81) was larger than the logistic European System for Cardiac Operative Risk Evaluation model (0.79; P = .0001). For different surgical operation categories, there were no differences in the discriminatory power for the artificial neural networks (P = .15) but significant differences were found for the logistic European System for Cardiac Operative Risk Evaluation (P = .0072).

CONCLUSIONS

Risk factors in a ranked order contributing to the mortality prediction were identified. A minimal set of risk variables achieving a superior mortality prediction was defined. The artificial neural network model is applicable independent of the cardiac surgical procedure.

EuroSCORE Predicts Immediate and Late Outcome After Coronary Artery Bypass Surgery

BACKGROUND

The European system for cardiac operative risk evaluation score (EuroSCORE) has been shown to be of value in identifying patients at high risk for adverse immediate postoperative outcome after adult cardiac surgery. The aim of the present study was to evaluate EuroSCORE in predicting the 12-year outcome of patients who underwent on-pump coronary artery bypass surgery (CABG).

METHODS

We calculated the EuroSCORE in 917 patients who underwent CABG. The median follow-up was 11.7 years.

RESULTS

Both additive and logistic EuroSCORE had an area under the receiver operating characteristic curve of 0.856 for prediction of 30-day postoperative death. Among 912 operative survivors, the 10-year survival rates according to quintiles of additive EuroSCORE were 87.9%, 83.9%, 85.2%, 76.0%, and 51.3% (p < 0.0001). The 10-year survival rates according to quintiles of logistic EuroSCORE were 87.9%, 85.4%, 86.5%, 76.9%, and 58.9% (p < 0.0001).

CONCLUSIONS

EuroSCORE is a relevant predictor of immediate and late outcome after on-pump CABG.

Preoperative calculation of risk for prolonged intensive care unit stay following coronary artery bypass grafting

Objective

Patients who have prolonged stay in intensive care unit (ICU) are associated with adverse outcomes. Such patients have cost implications and can lead to shortage of ICU beds. We aimed to develop a preoperative risk prediction tool for prolonged ICU stay following coronary artery surgery (CABG).

Methods

5,186 patients who underwent CABG between 1st April 1997 and 31st March 2002 were analysed in a development dataset. Logistic regression was used with forward stepwise technique to identify preoperative risk factors for prolonged ICU stay; defined as patients staying longer than 3 days on ICU. Variables examined included presentation history, co-morbidities, catheter and demographic details. The use of cardiopulmonary bypass (CPB) was also recorded. The prediction tool was tested on validation dataset (1197 CABG patients between 1^st April 2003 and 31^st March 2004). The area under the receiver operating characteristic (ROC) curve was calculated to assess the performance of the prediction tool.

Results

475(9.2%) patients had a prolonged ICU stay in the development dataset. Variables identified as risk factors for a prolonged ICU stay included renal dysfunction, unstable angina, poor ejection fraction, peripheral vascular disease, obesity, increasing age, smoking, diabetes, priority, hypercholesterolaemia, hypertension, and use of CPB. In the validation dataset, 8.1% patients had a prolonged ICU stay compared to 8.7% expected. The ROC curve for the development and validation datasets was 0.72 and 0.74 respectively.

Conclusion

A prediction tool has been developed which is reliable and valid. The tool is being piloted at our institution to aid resource management.

Risk stratification models fail to predict hospital costs of cardiac surgery patients

BACKGROUND

The aim of this prospective study was to determine if commonly used risk stratification models can predict total hospital costs in cardiac surgical patients.

METHODS

Between October 1st and December 31st 2003, all consecutive adult patients undergoing cardiac surgery on CPB at our institution were classified using seven risk stratification scoring systems: EuroSCORE, Cleveland, Parsonnet, Ontario, French, Pons, and CABDEAL. Total hospital costs for each patient were calculated on a daily basis including preoperative diagnostic tests, operating room costs, disposable materials, drugs, blood components, costs for personnel, and hospital fixed-costs. Linear regression analysis was used to determine the correlation between costs and the seven risk stratifications models as well as length of stay (LOS) on ICU. The Spearman correlation coefficient was calculated from the regression line, and an analysis of residuals was performed to determine the quality of the regression.

RESULTS

A total of 252 patients were operated for CABG (n=175), valve (n=39), CABG plus valve (n=21), thoracic aorta (n=13) and miscellaneous (2 myxoma, 1 ASD, 1 pulmonary embolism). Mean age of the patients was 66.0+/-11.4 years, 29.4% were female. LOS on ICU was 3.3+/-6.3 days and the 30-day mortality rate was 6.7%. Spearman correlation between the seven risk stratification models and hospital costs was below r=0.32 (p=0.0001), but was r=0.94 (p=0.0001) between ICU LOS and costs.

CONCLUSIONS

Total hospital costs can be identified by length of ICU stay. None of the common risk stratification models accurately predicted total hospital costs in cardiac surgical patients.

Preoperative White Blood Cell Count is Independently Associated With Higher Perioperative Cardiac Enzyme Release and Increased 1-Year Mortality After Coronary Artery Bypass Grafting

BACKGROUND

Elevated preprocedural systemic markers of inflammation, including white blood cell count, have been associated with adverse clinical outcomes after percutaneous coronary intervention. The relationship between preoperative white blood cell count and clinical outcomes after coronary artery bypass grafting is less clear despite increasing evidence that neutrophils participate in reperfusion injury. We sought to determine the relationship between preoperative white blood cell count and in hospital major morbidity and 1-year survival after coronary artery bypass grafting.

METHODS

We prospectively studied 3,024 consecutive isolated coronary artery bypass graft procedures. Preoperative white blood cell count was determined by automated counter, perioperative cardiac enzyme release by the creatine kinase-myocardial band isoenzyme, and all-cause mortality over the first postoperative year taken from a national death registry. Multivariate logistic regression and Cox proportional hazards analyses were performed.

RESULTS

Preoperative white blood cell count offered as a continuous variable and as five predetermined groups was independently associated with cardiac enzyme release three or more times the upper limit of the reference range (adjusted odds ratio = 1.5 per 10 x 10(9)/L increase, 95% confidence interval: 1.2 to 2.0, p = 0.002) and higher 1-year mortality (adjusted hazard ratio = 1.6 per 10 x 10(9)/L increase, 95% confidence interval: 1.2 to 2.1, p < 0.001).

CONCLUSIONS

Higher preoperative white blood cell count is independently associated with higher perioperative myonecrosis and 1-year mortality after coronary artery bypass grafting.

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.

Recombinant Factor VIIa in the Treatment of Postoperative Hemorrhage After Cardiac Surgery

BACKGROUND

A generalized coagulation disorder after cardiac surgery that is associated with massive postoperative hemorrhage is not completely understood. Recombinant factor VIIa (rFVIIa) has emerged as a possible "salvage" medication. Limited experience reported in the literature and fears of possible thromboembolic complications make the use of rFVIIa in the treatment of bleeding after cardiac surgery controversial.

METHODS

We analyzed retrospectively all consecutive cardiac surgical patients who have received rFVIIa in the Helsinki University Hospital in order to evaluate the safety and efficacy of rFVIIa after cardiac surgery in our institution. Altogether, 16 patients were identified from operating room and intensive care unit (ICU) databases. Patient records and operating room and ICU databases were reviewed.

RESULTS

In this series of high risk patients hospital mortality was high (25%). A definite hemostatic effect was seen after rFVIIa administration in all but three patients (82%). Mean amount of bleeding and amount of platelet and fresh frozen plasma transfusions decreased significantly after rFVIIa administration. Four patients had serious postoperative thromboembolic complications.

CONCLUSIONS

Recombinant factor VIIa was effective in restoring hemostasis, but thromboembolic complications occurred after rFVIIa use. They may be related to the underlying pathologies and surgery performed. It is possible, however, that rFVIIa treatment contributed to their occurrence.