|
|
||||||||
Ann Thorac Surg 1997;63:903-908
© 1997 The Society of Thoracic Surgeons
Division of Cardiothoracic Surgery, University of Florida Health Science Center, Jacksonville, Florida; University of Colorado Health Science Center, Denver, Colorado; and Summit Medical Systems, Minneapolis, Minnesota
| Abstract |
|---|
|
|
|---|
Methods. Logistic regression analysis was used to develop a risk model for each calendar year. A standard "training set/test set" approach was used for each model.
Results. Five validation techniques were used to evaluate the reliability of the risk models. All models were found to predict operative mortality with good accuracy in this population.
Conclusions. The new risk models for isolated coronary artery bypass operations serve as reliable predictors of operative mortality for the most recent harvest of patient data from The Society of Thoracic Surgeons National Cardiac Surgery Database.
| Introduction |
|---|
|
|
|---|
The changing profile of patients undergoing cardiac operations requires continuous updating and revision of the models to accurately reflect the current clinical milieu. With each new harvest of data, several different models based on a variety of statistical techniques have been compared. Before the most recent harvest, a Bayesian model had proven most accurate and was made available to participants as an integral part of the software package [1]. The patient data covering the 1990 to 1994 time frame, however, have been most accurately modeled by a logistic regression algorithm. The purpose of this report is to present the data and techniques used to develop this model of CABG operative mortality so that surgeons may be fully informed of the statistical tools used in the most current update of the STS Database.
| Material and Methods |
|---|
|
|
|---|
|
The modeling process followed a standard "training set/test set" approach in which patients were randomly assigned into one of two groups of approximately equal size. The "training set" population was used to develop the model, whereas the "test set" was used to test the model against observed results.
Statistical Analysis System (SAS) software (Version 6.09 for Windows; SAS Institute, Cary, NC) was used for all analyses. Each risk factor contained in the STS Database form was considered for inclusion in the models. A stepwise multivariate analysis of these risk factors was carried out to determine those patient variables that were independently associated with operative mortality. Variables were entered and removed by a stepwise selection process in which residual Wald
2 p values for entry and retention were 0.2 and 0.1, respectively. These entry and retention values were selected so as to allow liberal inclusion of risk factors in the model.
After determining the appropriate risk factors, a standard stepwise logistic regression analysis was performed using the "training set" population to develop a risk equation of the form:
![]() | (1) |
where P = the probability of postoperative death; and X = B0X0 + B1X1 + ...BkXk, where each B value is a constant associated with a specific risk factor, and the X values denote the status of the risk factor for a given patient. It should be mentioned that this equation, like any other, consists of constants and variables. The constants (B values) are derived from the patient population, whereas the variables consist of the presence or absence of each risk factor for a given patient. After the risk factors for a specific patient are entered into the model, the mathematic calculations are carried out to yield the predicted probability of operative mortality for that patient. All patients in the "test set" population were used to determine the validity of the model.
Validation of the Models
Risk factors for each patient in the "test set" population were entered into the logistic risk equation to calculate the probability of operative death for that patient. To ensure validity, the models were subjected to several statistical tests.
The most direct approach is simply to compare the predicted mortality against the observed mortality for the entire "test set" population encompassed by the model. As shown in Table 2
, there was excellent agreement for each of the models.
|
|
|
|
| Results |
|---|
|
|
|---|
|
Other approaches to model validation involve more theoretic statistical techniques. The Hosmer-Lemeshow test determines calibration, which is a measure of performance across the risk spectrum. This test reflects the reliability of the model in low-, moderate-, and high-risk patients. The population is arranged from lowest to highest risk and divided into ten groups of equal size. A
2 test is then applied using a 2 x 10 matrix with 8 degrees of freedom. A p value less than 0.05 indicates a statistically significant deviation in model performance across the risk spectrum. As shown in Table 3
, the 1994 model demonstrated poor calibration, but the other tests of validity were very favorable for this model. In particular, its c-index confirms good discrimination (see Table 3
) and, most important, there is excellent agreement between predicted and observed results (see Figs 1E, 2E![]()
). These favorable validation findings appear to outweigh the issue of calibration in this case, and one may justifiably conclude that the 1994 model is a reliable predictor of CABG operative mortality.
The c-index reflects the ability of the model to discriminate between possible outcomes (survival versus nonsurvival in this case). A useless model would have a c-index of 0.5, indicating that the model would predict one outcome to be just as likely as any other. A c-index of 1.0 would be found in a "perfect" model. Generally, values greater than 0.75 are consistent with an excellent ability to discriminate between possible outcomes. In each of the five STS models, the c-index was in this range (see Table 3
).
| Comment |
|---|
|
|
|---|
Risk-assessment models are most commonly used as a quality assurance/quality improvement tool. In this setting, data from a group of patients are run through the model to determine the predicted mortality adjusted for patient risk. Practically speaking, if this predicted mortality is X percent, the following may be stated: "Based on the accumulated national experience of the STS Database, a group of patients having these risk factors would be expected to have an operative mortality of X percent." The extensive nature of the STS Database and the scrutiny to which its data are subjected suggest that this predicted mortality represents an acceptable standard. Predicted mortality is then compared with the actual observed mortality. There is universal agreement that this method of risk stratification is absolutely essential for a meaningful analysis of operative results.
Risk assessment is a continuous process in which the harvest of new data necessitates a reassessment of modeling techniques. New patient data are brought into the STS Database annually. These new data are analyzed, modeled, and tested with a variety of statistical algorithms. The technique that provides the best results is presented to the STS National Database for Thoracic Surgery Committee and to the STS Database Liaison Committee for further examination. Upon approval, thenew models are made available to STS Database participants.
The initial models were based on a Bayesian algorithm and generally performed very well [1]. One of the major advantages of Bayesian models is the ability to handle incomplete data, which were more common in the early stages of database development. In recent years, more careful data entry, better familiarization with the process, and detailed auditing techniques have led to a marked improvement in data quality. Possibly because of this enhanced data quality, we have found that Bayesian advantages now have a lesser impact, and logistic regression techniques are most suitable for modeling current patient data.
In conclusion, the latest risk models developed from the STS Database provide a reliable and statistically valid method to stratify CABG patients into appropriate risk categories. These predictive models of CABG operative mortality have become practical tools that surgeons may use to analyze operative results, facilitate patient counseling, and enhance medical decision making.
| Footnotes |
|---|
|
|
|---|
| References |
|---|
|
|
|---|
This article has been cited by other articles:
![]() |
J. D. Blasberg, G. S. Schwartz, and S. K. Balaram The role of gender in coronary surgery Eur J Cardiothorac Surg, September 1, 2011; 40(3): 715 - 721. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. C. Stamou, M. Nussbaum, J. D. Carew, K. Dunn, E. Skipper, F. Robicsek, and K. W. Lobdell Hypoglycemia with intensive insulin therapy after cardiac surgery: Predisposing factors and association with mortality J. Thorac. Cardiovasc. Surg., July 1, 2011; 142(1): 166 - 173. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Saito, N. Motomura, H. Miyata, S. Takamoto, S. Kyo, M. Ono, and Japan Cardiovascular Surgery Database Organization Age-specific risk stratification in 13488 isolated coronary artery bypass grafting procedures Interact CardioVasc Thorac Surg, April 1, 2011; 12(4): 575 - 581. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Lee, S. Li, J. S. Rankin, S. M. O'Brien, J. S. Gammie, E. D. Peterson, P. M. McCarthy, F. H. Edwards, and The Society of Thoracic Surgeons Adult Cardiac Sur Fifteen-Year Outcome Trends for Valve Surgery in North America Ann. Thorac. Surg., March 1, 2011; 91(3): 677 - 684. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Ata, J. Lee, S. L. Bestle, J. Desemone, and S. C. Stain Postoperative Hyperglycemia and Surgical Site Infection in General Surgery Patients Arch Surg, September 1, 2010; 145(9): 858 - 864. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Frisch, P. Chandra, D. Smiley, L. Peng, M. Rizzo, C. Gatcliffe, M. Hudson, J. Mendoza, R. Johnson, E. Lin, et al. Prevalence and Clinical Outcome of Hyperglycemia in the Perioperative Period in Noncardiac Surgery Diabetes Care, August 1, 2010; 33(8): 1783 - 1788. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Jin, A. P. Furnary, S. C. Fine, E. H. Blackstone, and G. L. Grunkemeier Using Society of Thoracic Surgeons Risk Models for Risk-Adjusting Cardiac Surgery Results Ann. Thorac. Surg., March 1, 2010; 89(3): 677 - 682. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. C. Malaisrie, P. M. McCarthy, E. C. McGee, R. Lee, V. H. Rigolin, C. J. Davidson, N. Beohar, B. Lapin, H. Subacius, and R. O. Bonow Contemporary Perioperative Results of Isolated Aortic Valve Replacement for Aortic Stenosis Ann. Thorac. Surg., March 1, 2010; 89(3): 751 - 756. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Caceres, R. L. Braud, and H. E. Garrett Jr A Short History of the Society of Thoracic Surgeons National Cardiac Database: Perceptions of a Practicing Surgeon Ann. Thorac. Surg., January 1, 2010; 89(1): 332 - 339. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. C. Carosella, J. L. Navia, S. Al-Ruzzeh, H. Grancelli, W. Rodriguez, C. Cardenas, J. Bilbao, and C. Nojek The first Latin-American risk stratification system for cardiac surgery: can be used as a graphic pocket-card score Interact CardioVasc Thorac Surg, August 1, 2009; 9(2): 203 - 208. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. Ad, S. D. Barnett, C. K. Haan, S. M. O'Brien, S. Milford-Beland, and A. M. Speir Does preoperative atrial fibrillation increase the risk for mortality and morbidity after coronary artery bypass grafting? J. Thorac. Cardiovasc. Surg., April 1, 2009; 137(4): 901 - 906. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. T.L. Chiam and C. E. Ruiz Percutaneous Transcatheter Aortic Valve Implantation: Assessing Results, Judging Outcomes, and Planning Trials: The Interventionalist Perspective J. Am. Coll. Cardiol. Intv., August 1, 2008; 1(4): 341 - 350. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. D'Alessandro, P. Leprince, J. L. Golmard, A. Ouattara, S. Aubert, A. Pavie, I. Gandjbakhch, and N. Bonnet Strict glycemic control reduces EuroSCORE expected mortality in diabetic patients undergoing myocardial revascularization J. Thorac. Cardiovasc. Surg., July 1, 2007; 134(1): 29 - 37. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. K. Thambidorai, S. J. Jaffer, T. K. Shah, W. J. Stewart, A. L. Klein, and M. S. Lauer Association of atheroma as assessed by intraoperative transoesophageal echocardiography with long-term mortality in patients undergoing cardiac surgery Eur. Heart J., June 6, 2007; (2007) ehm180v1. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. J. Kumbhani, N. A. Healey, H. S. Thatte, S. Nawas, M. D. Crittenden, V. Birjiniuk, P. R. Treanor, and S. F. Khuri Patients with diabetes mellitus undergoing cardiac surgery are at greater risk for developing intraoperative myocardial acidosis J. Thorac. Cardiovasc. Surg., June 1, 2007; 133(6): 1566 - 1572. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. S. Adabag, T. Rector, S. Mithani, J. Harmala, H. B. Ward, R. F. Kelly, J. T. Nguyen, E. O. McFalls, and H. E. Bloomfield Prognostic Significance of Elevated Cardiac Troponin I After Heart Surgery Ann. Thorac. Surg., May 1, 2007; 83(5): 1744 - 1750. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. W.W. Wong and K.-H. Mak Impact of Maze and Concomitant Mitral Valve Surgery on Clinical Outcomes Ann. Thorac. Surg., November 1, 2006; 82(5): 1938 - 1947. [Abstract] [Full Text] [PDF] |
||||
![]() |
Determinants of operative mortality in valvular heart surgery. J. Thorac. Cardiovasc. Surg., March 1, 2006; 131(3): 547 - 557. |
||||
![]() |
F. Seccareccia, C. A. Perucci, P. D'Errigo, M. Arca, D. Fusco, S. Rosato, D. Greco, and on behalf of the research group of the Italian CAB The Italian CABG Outcome Study: short-term outcomes in patients with coronary artery bypass graft surgery Eur J Cardiothorac Surg, January 1, 2006; 29(1): 56 - 62. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Jin, L. F. Hiratzka, G. L. Grunkemeier, A. Krause, and U. S. Page III Aborted Off-Pump Coronary Artery Bypass Patients Have Much Worse Outcomes Than On-Pump or Successful Off-Pump Patients Circulation, August 30, 2005; 112(9_suppl): I-332 - I-337. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Jin, G. L. Grunkemeier, A. P. Furnary, J. R. Handy Jr, and for the Providence Health System Cardiovascular St Is Obesity a Risk Factor for Mortality in Coronary Artery Bypass Surgery? Circulation, June 28, 2005; 111(25): 3359 - 3365. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. M. Shahian, E. H. Blackstone, F. H. Edwards, F. L. Grover, G. L. Grunkemeier, D. C. Naftel, S. A.M. Nashef, W. C. Nugent, and E. D. Peterson Cardiac Surgery Risk Models: A Position Article Ann. Thorac. Surg., November 1, 2004; 78(5): 1868 - 1877. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Z. Omar, G. Ambler, P. Royston, J. Eliahoo, and K. M. Taylor Cardiac surgery risk modeling for mortality: a review of current practice and suggestions for improvement Ann. Thorac. Surg., June 1, 2004; 77(6): 2232 - 2237. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. A. Quader, P. M. McCarthy, A. M. Gillinov, J. M. Alster, D. M. Cosgrove III, B. W. Lytle, and E. H. Blackstone Does preoperative atrial fibrillation reduce survival after coronary artery bypass grafting? Ann. Thorac. Surg., May 1, 2004; 77(5): 1514 - 1524. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. C. Gardner, G. K. Grunwald, J. S. Rumsfeld, J. C. Cleveland Jr, L. M. Schooley, D. Gao, F. L. Grover, G. O. McDonald, and A. L. Shroyer Comparison of short-term mortality risk factors for valve replacement versus coronary artery bypass graft surgery Ann. Thorac. Surg., February 1, 2004; 77(2): 549 - 556. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. M. Davierwala, M. Maganti, and T. M. Yau Decreasing significance of left ventricular dysfunction and reoperative surgery in predicting coronary artery bypass grafting-associated mortality: A twelve-year study J. Thorac. Cardiovasc. Surg., November 1, 2003; 126(5): 1335 - 1344. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. P. Goodney, G. T. O'Connor, D. E. Wennberg, and J. D. Birkmeyer Do hospitals with low mortality rates in coronary artery bypass also perform well in valve replacement? Ann. Thorac. Surg., October 1, 2003; 76(4): 1131 - 1137. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. Iung, G. Baron, E. G. Butchart, F. Delahaye, C. Gohlke-Barwolf, O. W. Levang, P. Tornos, J.-L. Vanoverschelde, F. Vermeer, E. Boersma, et al. A prospective survey of patients with valvular heart disease in Europe: The Euro Heart Survey on Valvular Heart Disease Eur. Heart J., July 1, 2003; 24(13): 1231 - 1243. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. H. Habib, A. Zacharias, T. A. Schwann, C. J. Riordan, S. J. Durham, and A. Shah Adverse effects of low hematocrit during cardiopulmonary bypass in the adult: Should current practice be changed? J. Thorac. Cardiovasc. Surg., June 1, 2003; 125(6): 1438 - 1450. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. A. Estrada, J. A. Young, L. Wiley Nifong, and W. R. Chitwood Jr Outcomes and perioperative hyperglycemia in patients with or without diabetes mellitus undergoing coronary artery bypass grafting Ann. Thorac. Surg., May 1, 2003; 75(5): 1392 - 1399. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. P. Furnary, G. Gao, G. L. Grunkemeier, Y. Wu, K. J. Zerr, S. O. Bookin, H. S. Floten, and A. Starr Continuous insulin infusion reduces mortality in patients with diabetes undergoing coronary artery bypass grafting J. Thorac. Cardiovasc. Surg., May 1, 2003; 125(5): 1007 - 1021. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. A. Ferraris and S. P. Ferraris Risk Stratification and Comorbidity Card. Surg. Adult, January 1, 2003; 2(2003): 187 - 224. [Full Text] |
||||
![]() |
D. A. Morrison, G. Sethi, J. Sacks, W. G. Henderson, F. Grover, S. Sedlis, R. Esposito, and Investigators of the Department of Veterans Affair Percutaneous coronary intervention versus repeat bypass surgery for patients with medically refractory myocardial ischemia: AWESOME randomized trial and registry experience with post-CABG patients J. Am. Coll. Cardiol., December 4, 2002; 40(11): 1951 - 1954. [Abstract] [Full Text] [PDF] |
||||
![]() |
P J Bradshaw, K Jamrozik, M Le, I Gilfillan, and P L Thompson Mortality and recurrent cardiac events after coronary artery bypass graft: long term outcomes in a population study Heart, December 1, 2002; 88(5): 488 - 494. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. P. Sedlis, D. A. Morrison, J. D. Lorin, R. Esposito, G. Sethi, J. Sacks, W. Henderson, F. Grover, K. B. Ramanathan, D. Weiman, et al. Percutaneous coronary intervention versus coronary bypass graft surgery for diabetic patients with unstable angina and risk factors for adverse outcomes with bypass: outcome of diabetic patients in the AWESOME randomized trial and registry J. Am. Coll. Cardiol., November 6, 2002; 40(9): 1555 - 1566. [Abstract] [Full Text] [PDF] |
||||
![]() |
Z. S. Meharwal, Y. K. Mishra, V. Kohli, R. Bapna, S. Singh, and N. Trehan Off-pump multivessel coronary artery surgery in high-risk patients Ann. Thorac. Surg., October 1, 2002; 74(4): S1353 - S1357. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. D. Peterson, L. P. Coombs, T. B. Ferguson, A. L. Shroyer, E. R. DeLong, F. L. Grover, and F. H. Edwards Hospital variability in length of stay after coronary artery bypass surgery: results from the Society of Thoracic Surgeon's National Cardiac Database Ann. Thorac. Surg., August 1, 2002; 74(2): 464 - 473. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. A. Schwann, A. Zacharias, C. J. Riordan, S. J. Durham, M. Engoren, and R. H. Habib Safe, highly selective use of pulmonary artery catheters in coronary artery bypass grafting: an objective patient selection method Ann. Thorac. Surg., May 1, 2002; 73(5): 1394 - 1401. [Abstract] [Full Text] [PDF] |
||||
![]() |
I. J. Welsby, E. Bennett-Guerrero, D. Atwell, W. D. White, M. F. Newman, P. K. Smith, and M. G. Mythen The Association of Complication Type with Mortality and Prolonged Stay After Cardiac Surgery with Cardiopulmonary Bypass Anesth. Analg., May 1, 2002; 94(5): 1072 - 1078. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. A. Clough, B. J. Leavitt, J. R. Morton, S. K. Plume, F. Hernandez, W. Nugent, S. J. Lahey, C. S. Ross, G. T. O'Connor, and for the Northern New England Cardiovascular Diseas The Effect of Comorbid Illness on Mortality Outcomes in Cardiac Surgery Arch Surg, April 1, 2002; 137(4): 428 - 433. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. B. Ferguson Jr, B. G. Hammill, E. D. Peterson, E. R. DeLong, and F. L. Grover A decade of change--risk profiles and outcomes for isolated coronary artery bypass grafting procedures, 1990-1999: a report from the STS National Database Committee and the Duke Clinical Research Institute Ann. Thorac. Surg., February 1, 2002; 73(2): 480 - 489. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. Sadeghi, S. Sadeghi, Z. A. Mood, and A. Karimi Determinants of operative mortality following primary coronary artery bypass surgery Eur J Cardiothorac Surg, February 1, 2002; 21(2): 187 - 192. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. L. Grover, J. C. Cleveland Jr, and L. W. Shroyer Quality Improvement in Cardiac Care Arch Surg, January 1, 2002; 137(1): 28 - 36. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. M. Shahian, S.-L. Normand, D. F. Torchiana, S. M. Lewis, J. O. Pastore, R. E. Kuntz, and P. I. Dreyer Cardiac surgery report cards: comprehensive review and statistical critique Ann. Thorac. Surg., December 1, 2001; 72(6): 2155 - 2168. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Demers and R. Cartier Multivessel off-pump coronary artery bypass surgery in the elderly Eur J Cardiothorac Surg, November 1, 2001; 20(5): 908 - 912. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. Trehan, M. Mishra, O. P. Sharma, A. Mishra, and R. R. Kasliwal Further reduction in stroke after off-pump coronary artery bypass grafting: a 10-year experience Ann. Thorac. Surg., September 1, 2001; 72(3): S1026 - S1032. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. H. Edwards, E. D. Peterson, L. P. Coombs, E. R. DeLong, W. R. E. Jamieson, A. L. W. Shroyer, and F. L. Grover Prediction of operative mortality after valve replacement surgery J. Am. Coll. Cardiol., March 1, 2001; 37(3): 885 - 892. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. C. Stamou and P. J. Corso Coronary revascularization without cardiopulmonary bypass in high-risk patients: a route to the future Ann. Thorac. Surg., March 1, 2001; 71(3): 1056 - 1061. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. S. Hartz, A. V. Rao, M. E. Plomondon, F. L. Grover, and A. L. W. Shroyer Effects of race, with or without gender, on operative mortality after coronary artery bypass grafting: a study using The Society of Thoracic Surgeons national database Ann. Thorac. Surg., February 1, 2001; 71(2): 512 - 520. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. B. Ferguson Jr, S. W. Dziuban Jr, F. H. Edwards, M. C. Eiken, A. L. W. Shroyer, P. C. Pairolero, R. P. Anderson, and F. L. Grover The STS National Database: current changes and challenges for the new millennium Ann. Thorac. Surg., March 1, 2000; 69(3): 680 - 691. [Abstract] [Full Text] [PDF] |
||||
![]() |
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] |
||||
![]() |
M. A. Groh, S. E. Sutherland, H. G. Burton III, A. M. Johnson, and S. W. Ely Port-access coronary artery bypass grafting: technique and comparative results Ann. Thorac. Surg., October 1, 1999; 68(4): 1506 - 1508. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. Roques, S. A. M. Nashef, P. Michel, E. Gauducheau, C. de Vincentiis, E. Baudet, J. Cortina, M. David, A. Faichney, F. Gavrielle, et al. Risk factors and outcome in European cardiac surgery: analysis of the EuroSCORE multinational database of 19030 patients Eur J Cardiothorac Surg, June 1, 1999; 15(6): 816 - 823. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. L. W. Shroyer, M. E. Plomondon, F. L. Grover, and F. H. Edwards The 1996 coronary artery bypass risk model: The Society of Thoracic Surgeons Adult Cardiac National Database Ann. Thorac. Surg., April 1, 1999; 67(4): 1205 - 1208. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. L. W. Shroyer, F. L. Grover, and F. H. Edwards 1995 Coronary Artery Bypass Risk Model: The Society of Thoracic Surgeons Adult Cardiac National Database Ann. Thorac. Surg., March 1, 1998; 65(3): 879 - 884. [Abstract] [Full Text] [PDF] |
||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 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 |