ATS
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
 QUICK SEARCH:   [advanced]


     


This Article
Right arrow Abstract Freely available
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to Personal Folders
Right arrow Download to citation manager
Right arrow Permission Requests
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Kurki, T. S. O.
Right arrow Articles by Kataja, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Kurki, T. S. O.
Right arrow Articles by Kataja, M.

Ann Thorac Surg 1996;61:1740-1745
© 1996 The Society of Thoracic Surgeons


Original Article: Cardiovascular

Preoperative Prediction of Postoperative Morbidity in Coronary Artery Bypass Grafting

Tuula S. O. Kurki, MD, Matti Kataja, PhD

Heart Center, Deaconess Hospital, and National Public Health Institute, Helsinki, Finland

Accepted for publication February 6, 1996.


    Abstract
 Top
 Footnotes
 Abstract
 Introduction
 Patients and Methods
 Results
 Comment
 Appendix 1.
 Acknowledgments
 References
 
Background. The risk factors of patients selected for coronary artery bypass grafting have increased in recent years because of the aging population. Prediction of postoperative complications is essential for optimal use of the available resources. The aim of this study was to develop a scoring method for prediction of postoperative morbidity of individual patients undergoing bypass grafting.

Methods. Data from 386 consecutive patients who underwent coronary artery bypass grafting in a single center were retrospectively collected. The relationship between the preoperative risk factors and the postoperative morbidity was analyzed by the Bayesian approach. Three risk indices (15-factor and seven-factor computed and seven-factor manual models) were developed for the prediction of morbidity. The criterion for morbidity was a prolonged hospital stay postoperatively (>12 days) because of adverse events.

Results. The best predictive preoperative factors for increased morbidity were emergency operation, diabetes, rhythm other than sinus rhythm on the electrocardiogram or recent myocardial infarction, low ejection fraction (<0.49), age greater than 70 years, decreased renal function, chronic pulmonary disease, cerebrovascular disease, and obesity. The sensitivity of the scoring methods ranged from 51% to 72% and the specificity, from 77% to 86%.

Conclusions. The results show that individual patients can be stratified according to postoperative risk for complications on the basis of preoperative information that is available for most patients.


    Introduction
 Top
 Footnotes
 Abstract
 Introduction
 Patients and Methods
 Results
 Comment
 Appendix 1.
 Acknowledgments
 References
 
The increasing use of coronary artery bypass grafting (CABG) to treat coronary artery disease sets high demands on the healthcare system. The risk factors of patients selected for CABG have increased in recent years [1]. Prediction of risk of postoperative complications is necessary for optimal use of the available resources. For individual hospitals, knowledge of the risk of delayed postoperative recovery would aid in the planning of capacity, allocation of monitoring resources, and choice of patients. Definition of the risk factors also makes it possible to compare patient populations and postoperative morbidity as well as costs in different hospitals. Risk equation would also facilitate the use of historical controls in the evaluation of new therapeutic measures.

Most studies addressing the risk factors of CABG were prompted by the need of quality control and fair comparison of the results in different hospitals. Several studies [29] with mortality as the end point have demonstrated preoperative risk factors for CABG and valve operations. The Coronary Artery Surgery Study group has developed a logistic risk equation for quality assurance [10]. The value of mortality as the sole end point has been questioned in the evaluation of clinical trials. Instead, morbidity has been suggested as a valid end point [11]. The aim of this study was to develop a simple, easily used preoperative risk model and to find the preoperative risk factors that best predict postoperative morbidity for CABG with special reference to prolonged hospital stay.


    Patients and Methods
 Top
 Footnotes
 Abstract
 Introduction
 Patients and Methods
 Results
 Comment
 Appendix 1.
 Acknowledgments
 References
 
Data Collection
The study protocol was approved by the institutional review board. Data from 386 consecutive patients who underwent CABG (in 1990 and 1991) in the Heart Center of Deaconess Hospital, Helsinki, were collected retrospectively. Files for 14 of the 400 patients were not available, and those patients were excluded from the study. The following preoperative data were collected: patient age (in years) and sex, body surface area and body mass index (weight in kilograms/square of the height in meters), New York Heart Association status and history of previous myocardial infarction or previous open heart operation, evaluation of preoperative electrocardiogram (rhythm and ST segment changes), priority of the operation (emergency or elective), and cardiac catheterization data: ejection fraction, left ventricular end-diastolic pressure, number of diseased vessels from one through three, occurrence of left main stenosis, degree of congestion, and size of the heart from the chest roentgenogram. Comorbidity factors were also collected: renal insufficiency, arterial hypertension, chronic pulmonary disease, cerebrovascular disease (with previous stroke), obesity, diabetes, and other endocrine disorders. The influence of the 21 preoperative variables on the probability of a postoperative short-term outcome were studied. There were a few missing observations: serum creatinine values for 20 patients, data about diabetes for 11 patients, type of operation (emergency versus elective) for 4 patients, presence of an abnormal electrocardiogram for 2 patients, and data on chronic pulmonary disease for 20 patients.

A complicated postoperative short-term outcome was defined as a prolonged hospital stay (>12 days) after operation because of adverse events, transfer to another hospital for treatment of complications, or death during the hospital stay. The following complications led to a prolonged hospitalization: central nervous system problems including stroke and hemiparesis, postoperative infection in the sternum or a leg wound, pulmonary infection, arrhythmia requiring pacing or cardioversion, renal failure postoperatively and need of dialysis, inotropic support, or intraaortic balloon pump, or death during the hospital stay.

Statistical Methods
Univariate analysis was first accomplished using a {chi}2 technique with 2 x 2 contingency tables to determine the relationship between the preoperative risk factors.

BAYESIAN ANALYSIS.
A stepwise Bayesian approach [3, 12, 13] was used to determine the posterior probabilities and likelihood ratios and to ascertain the sensitivity and the specificity of the rule. The Bayesian method is described in Appendix 1. A receiver operating characteristics (ROC) curve was also calculated. It gives a graphic representation of the relationship between true-positive and false-positive rates and can be used to study the effect of changing the decision rule. The area under the ROC curve is commonly used to measure the predictive power of a statistical model [14].

DERIVATION OF INDICES.
We have developed an optimization process to make the Bayesian analysis easier. The program goes through all the possible variables and selects first only one variable that will best predict the selected outcome (prolonged hospital stay in our study). Then the program goes through all the remaining variables and selects as a second variable the one that will best predict the outcome together with the first variable. Adding one variable after another to the model, the program goes through all the variables. The optimum is the number of variables that together give the smallest error rate (best sensitivity and specificity) in the study group. Usually the optimum does not include all the variables. At the end, the program provides the best combination of variables that will most accurately predict the outcome. It also gives the critical area for the total risk index, where the number of false-negative and false-positive results are minimal. The program also calculates the ROC curve. The program makes an assumption that the variables are independent of each other. The model ignores the interrisk factor correlations.

We used the Bayesian optimization process to find the combination of factors that will best predict morbidity. The program selected 15 of the 21 variables for the first model. Then we deleted one factor at a time from the model and tested the result. We ended up with a seven-factor short binary model. On the basis of the information in this short model, another model that needs no computing was developed. After weighing the factors for ``risk'' (1 to 2 points) and ``no risk'' (0 points) values, we ended up with a model that has a total score of 10 and an individual score for factors between 0 and 2.


    Results
 Top
 Footnotes
 Abstract
 Introduction
 Patients and Methods
 Results
 Comment
 Appendix 1.
 Acknowledgments
 References
 
The hospital records of 386 patients were analyzed. Patient demographics and outcomes are shown in Table 1Go. Of the 386 patients, 89 were in the hospital for longer than 12 days postoperatively or were transported to another hospital. Arrhythmia (mainly atrial fibrillation) was the most common reason for a prolonged hospital stay (65/89 patients) and infections (sternum, 3 patients; leg wound, 8; and pulmonary, 2), the next most common. Hemiparesis occurred in 5 patients and postoperative disorientation in 3. Two patients had low cardiac output requiring inotropic support, and another required intraaortic balloon pump treatment. One patient needed dialysis because of renal failure postoperatively. The hospital (<30 days) mortality rate was 1.6% (6/386 patients).


View this table:
[in this window]
[in a new window]
 
Table 1. . Preoperative Demographic Variables and Outcomea
 
The 15-factor optimal model with values (definition of attribute type variable) and weights (derived from relative risk by transformation: weight = 10 + 10 x Log [relative risk]) is presented in Table 2Go. Emergency operation, ST-segment changes or rhythm other than sinus rhythm on the preoperative electrocardiogram; low ejection fraction (<0.49), and age greater than 70 years were the most important factors predictive of postoperative complications and prolonged hospital stay. The existence of the following comorbidity factors further increased the risk of postoperative morbidity: obesity, diabetes mellitus, renal insufficiency or neurologic symptoms persisting after stroke or severe obstructive pulmonary disease with bronchodilator treatment, and poor lung function with a forced expiratory volume in 1 second of less than 50% of normal.


View this table:
[in this window]
[in a new window]
 
Table 2. . Additive Model With Values and Weights for the 15 Most Important Variablesa
 
In the longer 15-factor model, the analysis gave 54 false-positive and 25 false-negative results compared with the observed results. The sensitivity of the rule was 72% and the specificity, 82%. The efficiency for the correct prediction was 80%, and the total error rate was 21%. The ROC curve gave an area under the curve value of 0.765.

The results of the shorter seven-factor model are presented in Table 3Go. This version gave 44 false-positive and 39 false-negative results compared with the observed results (Tables 4, 5GoGo). The sensitivity of the rule was 51% and the specificity, 87%. The efficiency for the correct prediction was 79% and the total error rate, 22%. The ROC curve gave an area under the curve value of 0.787.


View this table:
[in this window]
[in a new window]
 
Table 3. . Additive Model With Values, Weights, and {chi}2 Values for the Seven Most Important Variablesa
 

View this table:
[in this window]
[in a new window]
 
Table 4. . Predicted and Observed Results of the Three Models
 

View this table:
[in this window]
[in a new window]
 
Table 5. . Sensitivity and Specificity of the Three Models
 
These seven factors were used to create a simple risk score that needs no computation. This clinical model, ``CABDEAL,'' will estimate the risk of a prolonged hospital stay in individual CABG patients. The factors were weighted on the basis of the relative contribution to the risk (Table 6Go). The predictive risk factors and their weighted ``at-risk'' scores are as follows: C = serum creatinine level greater than 110 µmol/L (>1.2 mg/dL), 2 points; A = age greater than 70 years, 1 point; B = body mass index greater than 28, 1 point; D = diabetes mellitus, 2 points; E = emergency operation, 2 points; A = abnormal electrocardiogram (nonsinus rhythm or ischemic ST segment changes), 1 point; and L = lung function (severe obstructive pulmonary disease or forced expiratory volume in 1 second < 50%), 1 point. The maximum sum of risk points is 10. The specificity (ie, risk of complications) increases as the sum of the scores increases. The sensitivity of this manual model was 56% and the specificity, 77% (when the sum of the score was 2). The ROC value was 0.713. This manual model gave 69 false-positive and 39 false-negative results at the score level 2. The higher the risk score, the greater the risk of increased morbidity and the better the specificity.


View this table:
[in this window]
[in a new window]
 
Table 6. . Short Manual Model With Seven Risk Factors
 
We took score level 2 as the cutoff point. If the patient has 0 or 1 risk point, the probability of postoperative morbidity is low (<15%), but if the score is 2 or higher, the probability of morbidity increases. In this study group, 31% of our patients had a score of 2 or higher. At score level 2, the probability of increased morbidity is 26%; score level 3, 46%; score level 4 or more, greater than 75%; and at score level 8, the probability of increased morbidity is 100%.

As an example of the manual CABDEAL, 1 of our patients had a preoperative creatinine level of 150 µmol/L (1.7 mg/dL) (2 points). He was 75 years old (1 point), and the body mass index was 29 (1 point). He also had diabetes (2 points). The operation was elective (0 point). The patient had chronic atrial fibrillation (1 point) and chronic obstructive pulmonary disease with a forced expiratory volume in 1 second of less than 50% of normal (1 point). The total score for this patient was 8. He had a prolonged hospitalization because of a wound infection in the leg and disorientation postoperatively. The patient also returned to atrial fibrillation in the intensive care unit on the first postoperative day. He was discharged from the hospital on postoperative day 15.


    Comment
 Top
 Footnotes
 Abstract
 Introduction
 Patients and Methods
 Results
 Comment
 Appendix 1.
 Acknowledgments
 References
 
Multifactorial risk indices have been developed to estimate the risk of cardiac complications in noncardiac surgical procedures [1517]. The index of Goldman and colleagues [15] has been in clinical use for several years. Our results suggest that the short-term postoperative outcome (morbidity) for individual patients and patient groups can be predicted with reasonable accuracy by using preoperative information available for virtually all patients scheduled for CABG. The computed models predicted postoperative complications with 51% to 72% sensitivity and more than 80% specificity depending on the number of factors. In addition, we have developed a simple manual scoring method that had a sensitivity of 56% and a specificity of 77%. This index, CABDEAL, can be used to identify individual patients with a high risk of postoperative complications.

The information about risk can be used for several purposes. The observation of high risk in an individual patient can influence the timing of the operation, the planning of the surgical procedure, the type of anesthesia (fast-track versus non-fast-track), and the resource allocation for postoperative observation and treatment or hospital discharge plan (``7-day package'' versus longer stay). It may help in comparing the results over time to estimate the impact of changes in therapeutic procedures. The index can also be used to compare the immediate results of CABG in different institutions. This kind of comparison is not possible without normalizing the risk factors in the patient populations treated in individual hospitals. The risk index may also provide an opportunity to estimate the treatment costs of a patient population.

The validity of the present findings for CABG patients in other hospitals and countries remains to be tested. Our study population consisted of patients with a wide variety of factors that influence outcome. The risk factor profile of the patients was typical for patients referred for CABG. Patients were treated by a small, experienced team, and this diminished the variability resulting from perioperative factors. The influence of local factors on the results cannot be excluded, and therefore the index has to be validated in other patient populations.

Many previous studies [210, 18, 19] have focused on postoperative mortality, whereas only a few studies have focused on short-term morbidity and complications. One previous study [20] measured outcome in patients after a cardiac operation on the basis of length of stay in the intensive care unit. One recent review article [21] concluded that there are several indices available to predict mortality from different institutions. However, there is a lack of easy-to-use models predicting individual risk for complications (morbidity). Our study gives an option for individual risk stratification of morbidity. Table 7Go compares the present results with those of four previous studies. All risk factors except the electrocardiographic abnormalities were found in at least two of the other studies. Emergency operation, renal dysfunction, diabetes, and pulmonary disease were identified as strong risk factors in at least three studies, including ours. Using univariate analysis and logistic regression analysis to relate risk factors for perioperative morbidity and mortality, Higgins and associates [22] studied a large CABG patient group. Their outcome measures were mortality and severe complications. Several of the risk factors were found in their study and our study: emergency procedure, elevated serum creatinine level, chronic pulmonary disease, and diabetes mellitus. Higgins and associates [22] also used an additive scoring system comprising 14 weighted factors that were graded from 1 through 6 giving a maximum total score of 33 points. Our manual scoring system had only seven factors that were graded 0 through 2 to give a maximum score of 10. The specificity and sensitivity of the two simplified risk scores were comparable. However, the CABDEAL model is easier to use at bedside for the evaluation of individual patients.


View this table:
[in this window]
[in a new window]
 
Table 7. . Most Important Preoperative Risk Factors for Postoperative Morbidity/Mortality: Comparison of Five Studies
 
In our study, the definitions of the risk factors were generally the same as those used by The Society of Thoracic Surgeons [23]. Those definitions were not available to us when the data were collected and analyzed in 1993. The Society of Thoracic Surgeons definitions were made to predict mortality, not morbidity. The criterion for increased creatinine level was greater than 110 µmol/L (>1.2 mg/dL) in our study, and greater than 177 µmol/L (>2.0 mg/dL) in the Society definition. Also, our definition of chronic pulmonary disease was stricter (forced expiratory volume in 1 second < 50% of normal value) than that of The Society (forced expiratory volume in 1 second < 75% of normal value).

In conclusion, patients selected for CABG can be stratified according to their risk of postoperative complications. This knowledge can be used both for patient groups and for individual patients.


    Appendix 1.
 Top
 Footnotes
 Abstract
 Introduction
 Patients and Methods
 Results
 Comment
 Appendix 1.
 Acknowledgments
 References
 
The Bayesian approach states how posterior probability P(D'x) is calculated using the prior probabilities P(D) and P(D`), which show how common the diagnosis D and its absence are in the population. The probabilities of symptoms given the diagnosis P(x'D) and P(x'D`) are commonly estimated by their frequencies in learning material [12, 13]. In the case of a two-valued outcome, the Bayesian approach is commonly developed to give a likelihood ratio. The likelihood ratio (L) of a set of observed symptoms of properties xi is written as the product of the probability ratios of each xi, also known as risk ratios in epidemiology:

L={pi}i[P(xi'D)/P(xi'D`)]

Posterior probability = L(x)/[1+L(x)]

The likelihood ratios are expressed in the tables as 10 x 10 based logarithms of the original values. A constant 10 has been added: 10 x [1 + log (L)]. If any risk factor value is missing, an estimate of 10 has been used. That will equal a likelihood value of 1.0. Thus, a missing value is interpreted as ``no risk.'' Similarly, missing values were given a value of 0 in the manual CABDEAL model.


    Acknowledgments
 Top
 Footnotes
 Abstract
 Introduction
 Patients and Methods
 Results
 Comment
 Appendix 1.
 Acknowledgments
 References
 
We thank the personnel of the Cardiac Intensive Care Unit, Helsinki Heart Center, for helping with data collection.


    Footnotes
 Top
 Footnotes
 Abstract
 Introduction
 Patients and Methods
 Results
 Comment
 Appendix 1.
 Acknowledgments
 References
 
Address reprint requests to Dr Kurki, Lukupolku 19, Helsinki 00680, Finland.


    References
 Top
 Footnotes
 Abstract
 Introduction
 Patients and Methods
 Results
 Comment
 Appendix 1.
 Acknowledgments
 References
 

  1. Clark RE. The Society of Thoracic Surgeons National Database status report. Ann Thorac Surg 1994;57:20–6.[Abstract]
  2. O'Connor G, Plume SK, Olmsteadt EM, et al. A regional prospective study of in-hospital mortality associated with coronary artery bypass grafting. JAMA 1991;266:803–9.[Abstract/Free Full Text]
  3. Edwards FH, Albus RA, Zajtchuk R, et al. Use of a Bayesian statistical model for risk assessment in coronary artery surgery. Ann Thorac Surg 1988;45:437–40.[Abstract]
  4. Parsonnet V, Dean D, Bernstein AD. A method of uniform stratification of risk for evaluating the results of surgery in acquired adult heart disease. Circulation 1989;79(Suppl 1):3–12.
  5. Wright JG, Pifarré R, Sullivan HJ, et al. Multivariate discriminant analysis of risk factors for operative mortality following isolated coronary artery bypass graft. Chest 1987;91:394–9.[Abstract/Free Full Text]
  6. Nashef SAM, Carey F, Silcock MM, Oommen PK, Levy RD, Jones MT. Risk stratification for open heart surgery: trial of the Parsonnet system in a British hospital. Br Med J 1992;305:1066–7.
  7. Junod FL, Harlan BJ, Payne J, et al. Preoperative risk assessment in cardiac surgery: comparison of predicted and observed results. Ann Thorac Surg 1987;43:59–64.[Abstract]
  8. Hannan EL, Kilburn H, O'Donnell J, Lukacik G, Shields EP. Adult open heart surgery in New York State. An analysis of risk factors and hospital mortality rates. JAMA 1990;264:2768–74.[Abstract/Free Full Text]
  9. Tu JV, Jaglal SB, Naylor D. Multicenter validation of a risk index for mortality, intensive care unit stay and overall hospital length of stay after cardiac surgery. Circulation 1995;91:677–84.[Abstract/Free Full Text]
  10. Kennedy JW, Kaiser GC, Fisher LD, et al. Multivariate discriminant analysis of the clinical angiographic predictors of operative mortality from the Collaborative Study in Coronary Artery Surgery (CASS). J Thorac Cardiovasc Surg 1980;80:876–87.[Abstract]
  11. Petros AJ, Marshall JC, van Saene HKF. Should morbidity replace mortality as an end-point for clinical trials in intensive care? Lancet 1995;345:369–71.[Medline]
  12. Marshall G, Shroyer ALW, Grover FL, Hammermeister KE. Bayesian-logit model for risk assessment in coronary artery bypass grafting. Ann Thorac Surg 1994;57:1492–1500.[Abstract]
  13. Schulman P. Bayes' theorem-a review. Cardiol Clin 1984;2:319–27.[Medline]
  14. Hanley JA, McNeil BJ. The meaning and use of the area under a receiver operating characteristics (ROC) curve. Radiology 1982;143:29–36.[Abstract/Free Full Text]
  15. Goldman L, Caldera DL, Nussbaum SR, et al. Multifactorial index of cardiac risk in noncardiac surgical procedures. N Engl J Med 1977;16:845–50.
  16. Goldman L. Multifactorial index of cardiac risk in noncardiac surgery: ten-year status report. J Cardiothorac Anesth 1987;3:237–44.
  17. Detsky AS, Abrams HB, Forbath N, Scott JG, Hilliard JR. Cardiac assessment for patients undergoing noncardiac surgery. Arch Intern Med 1986;146:2131–4.[Abstract/Free Full Text]
  18. Edwards FH, Clark RE, Schwartz M. Coronary artery bypass grafting: The Society of Thoracic Surgeons National Database experience. Ann Thorac Surg 1994;57:12–9.[Abstract]
  19. Hannan EL, Kilburn H, Racz M, Schields E, Chassin M. Improving the outcomes of coronary artery bypass surgery in New York State. JAMA 1994;271:761–6.[Abstract/Free Full Text]
  20. Holmes L, Loughead K, Treasure T, Gallivan S. Which patients will not benefit from further intensive care after cardiac surgery? Lancet 1994;344:1200–2.[Medline]
  21. Parsonnet V. Risk stratification in cardiac surgery: is it worthwhile? J Cardiac Surg 1995;10:690–8.[Medline]
  22. Higgins TL, Estafanous FG, Loop FD, Beck GJ, Blum JM, Paranandi L. Stratification of morbidity and mortality outcome by preoperative risk factors in coronary artery bypass patients. JAMA 1992;267:2344–8.[Abstract/Free Full Text]
  23. Clark RE. Definitions of terms of The Society of Thoracic Surgeons National Cardiac Surgery Database. Ann Thorac Surg 1994;58:271–3.



This article has been cited by other articles:


Home page
J. Thorac. Cardiovasc. Surg.Home page
A. T. Turer, K. W. Mahaffey, E. Honeycutt, R. H. Tuttle, L. K. Shaw, M. H. Sketch Jr., P. K. Smith, R. M. Califf, and J. H. Alexander
Influence of body mass index on the efficacy of revascularization in patients with coronary artery disease.
J. Thorac. Cardiovasc. Surg., June 1, 2009; 137(6): 1468 - 1474.
[Abstract] [Full Text] [PDF]


Home page
Int J Qual Health CareHome page
A. Kable, R. Gibberd, and A. Spigelman
Predictors of adverse events in surgical admissions in Australia
Int. J. Qual. Health Care, December 1, 2008; 20(6): 406 - 411.
[Abstract] [Full Text] [PDF]


Home page
Eur. J. Cardiothorac. Surg.Home page
A. L.P. Markou, A. van der Windt, H. A. van Swieten, and L. Noyez
Changes in quality of life, physical activity, and symptomatic status one year after myocardial revascularization for stable angina
Eur. J. Cardiothorac. Surg., November 1, 2008; 34(5): 1009 - 1015.
[Abstract] [Full Text] [PDF]


Home page
SEMIN CARDIOTHORAC VASC ANESTHHome page
J. Granton and D. Cheng
Risk Stratification Models for Cardiac Surgery
Seminars in Cardiothoracic and Vascular Anesthesia, September 1, 2008; 12(3): 167 - 174.
[Abstract] [PDF]


Home page
Nephrol Dial TransplantHome page
D. M. Charytan and R. E. Kuntz
Risks of coronary artery bypass surgery in dialysis-dependent patients--analysis of the 2001 National Inpatient Sample
Nephrol. Dial. Transplant., June 1, 2007; 22(6): 1665 - 1671.
[Abstract] [Full Text] [PDF]


Home page
Eur Heart JHome page
J. Nilsson, L. Algotsson, P. Hoglund, C. Luhrs, and J. Brandt
Comparison of 19 pre-operative risk stratification models in open-heart surgery
Eur. Heart J., April 1, 2006; 27(7): 867 - 874.
[Abstract] [Full Text] [PDF]


Home page
J. Thorac. Cardiovasc. Surg.Home page
M. J. Holzmann, S. Ahnve, N. Hammar, L. Jorgensen, K. Klerdal, K. Pehrsson, and T. Ivert
Creatinine clearance and risk of early mortality in patients undergoing coronary artery bypass grafting
J. Thorac. Cardiovasc. Surg., September 1, 2005; 130(3): 746 - 746.
[Abstract] [Full Text] [PDF]


Home page
J. Thorac. Cardiovasc. Surg.Home page
J. H. Shuhaiber
Epidemiologic contrast of predictors' trends for outcomes of coronary artery bypass grafting: Heart failure versus ventricular function versus left main disease
J. Thorac. Cardiovasc. Surg., June 1, 2004; 127(6): 1854 - 1855.
[Full Text] [PDF]


Home page
Eur. J. Cardiothorac. Surg.Home page
O. Jarvinen, T. Saarinen, J. Julkunen, H. Huhtala, and M. R. Tarkka
Changes in health-related quality of life and functional capacity following coronary artery bypass graft surgery
Eur. J. Cardiothorac. Surg., November 1, 2003; 24(5): 750 - 756.
[Abstract] [Full Text] [PDF]


Home page
Eur. J. Cardiothorac. Surg.Home page
P. Pinna Pintor, M. Bobbio, S. Colangelo, F. Veglia, R. Marras, and M. Diena
Can EuroSCORE predict direct costs of cardiac surgery?
Eur. J. Cardiothorac. Surg., April 1, 2003; 23(4): 595 - 598.
[Abstract] [Full Text] [PDF]


Home page
Ann. Thorac. Surg.Home page
C. C. Canver and J. Chanda
Intraoperative and postoperative risk factors for respiratory failure after coronary bypass
Ann. Thorac. Surg., March 1, 2003; 75(3): 853 - 857.
[Abstract] [Full Text] [PDF]


Home page
ptjournalHome page
E. H. Hulzebos, N. L. Van Meeteren, R. A De Bie, P. C Dagnelie, and P. J. Helders
Prediction of Postoperative Pulmonary Complications on the Basis of Preoperative Risk Factors in Patients Who Had Undergone Coronary Artery Bypass Graft Surgery
Physical Therapy, January 1, 2003; 83(1): 8 - 16.
[Abstract] [Full Text] [PDF]


Home page
Eur. J. Cardiothorac. Surg.Home page
P. Pinna Pintor, S. Colangelo, and M. Bobbio
Evolution of case-mix in heart surgery: from mortality risk to complication risk
Eur. J. Cardiothorac. Surg., December 1, 2002; 22(6): 927 - 933.
[Abstract] [Full Text] [PDF]


Home page
J Am Coll CardiolHome page
J. L. Carson, P. M. Scholz, A. Y. Chen, E. D. Peterson, J. Gold, and S. H. Schneider
Diabetes mellitus increases short-term mortality and morbidity in patients undergoing coronary artery bypass graft surgery
J. Am. Coll. Cardiol., August 7, 2002; 40(3): 418 - 423.
[Abstract] [Full Text] [PDF]


Home page
Eur. J. Cardiothorac. Surg.Home page
T. S. Kurki, O. Jarvinen, M. J. Kataja, J. Laurikka, and M. Tarkka
Performance of three preoperative risk indices; CABDEAL, EuroSCORE and Cleveland models in a prospective coronary bypass database
Eur. J. Cardiothorac. Surg., March 1, 2002; 21(3): 406 - 410.
[Abstract] [Full Text] [PDF]


Home page
Eur. J. Cardiothorac. Surg.Home page
T.S. Kurki, U. Hakkinen, J. Lauharanta, J. Ramo, and M. Leijala
Evaluation of the relationship between preoperative risk scores, postoperative and total length of stays and hospital costs in coronary bypass surgery
Eur. J. Cardiothorac. Surg., December 1, 2001; 20(6): 1183 - 1187.
[Abstract] [Full Text] [PDF]


Home page
ChestHome page
P. Branca, P. McGaw, and R. W. Light
Factors Associated With Prolonged Mechanical Ventilation Following Coronary Artery Bypass Surgery
Chest, February 1, 2001; 119(2): 537 - 546.
[Abstract] [Full Text] [PDF]


Home page
CirculationHome page
J. Y. Liu, N. J. O. Birkmeyer, J. H. Sanders, J. R. Morton, H. F. Henriques, S. J. Lahey, R. W. Dow, C. Maloney, A. W. DiScipio, R. Clough, et al.
Risks of Morbidity and Mortality in Dialysis Patients Undergoing Coronary Artery Bypass Surgery
Circulation, December 12, 2000; 102(24): 2973 - 2977.
[Abstract] [Full Text] [PDF]


Home page
Ann. Thorac. Surg.Home page
J. D. Puskas, A. D. Winston, C. E. Wright, J. P. Gott, W. M. Brown III, J. M. Craver, E. L. Jones, R. A. Guyton, and W. S. Weintraub
Stroke after coronary artery operation: incidence, correlates, outcome, and cost
Ann. Thorac. Surg., April 1, 2000; 69(4): 1053 - 1056.
[Abstract] [Full Text] [PDF]


Home page
Eur. J. Cardiothorac. Surg.Home page
T. Busch, H. Sirbu, I. Aleksic, S. Kazmaier, M. Friedrich, W. Buhre, and H. Dalichau
Combined approach for internal carotid artery stenosis and cardiovascular disease in septuagenarians - a comparative study
Eur. J. Cardiothorac. Surg., December 1, 1999; 16(6): 602 - 606.
[Abstract] [Full Text] [PDF]


Home page
Eur. J. Cardiothorac. Surg.Home page
M. Chello, P. Mastroroberto, F. Cirillo, E. Bevacqua, A. Carrano, F. Perticone, and A. R. Marchese
Neutrophil-endothelial cells modulation in diabetic patients undergoing coronary artery bypass grafting
Eur. J. Cardiothorac. Surg., October 1, 1999; 14(4): 373 - 379.
[Abstract] [Full Text] [PDF]


Home page
J Am Coll CardiolHome page
K. A. Eagle, R. A. Guyton, R. Davidoff, G. A. Ewy, J. Fonger, T. J. Gardner, J. P. Gott, H. C. Herrmann, R. A. Marlow, W. C. Nugent, et al.
ACC/AHA guidelines for coronary artery bypass graft surgery: A report of the American College of Cardiology/ American Heart Association task force on Practice Guidelines (Committee to revise the 1991 Guidelines for Coronary Artery Bypass Graft Surgery)
J. Am. Coll. Cardiol., October 1, 1999; 34(4): 1262 - 1347.
[Full Text] [PDF]


This Article
Right arrow Abstract Freely available
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to Personal Folders
Right arrow Download to citation manager
Right arrow Permission Requests
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Kurki, T. S. O.
Right arrow Articles by Kataja, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Kurki, T. S. O.
Right arrow Articles by Kataja, M.


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
ANN THORAC SURG ASIAN CARDIOVASC THORAC ANN EUR J CARDIOTHORAC SURG
J THORAC CARDIOVASC SURG ICVTS ALL CTSNet JOURNALS