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Ann Thorac Surg 2009;87:1820-1827. doi:10.1016/j.athoracsur.2009.03.052
© 2009 The Society of Thoracic Surgeons
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Right arrow Coronary disease

Original Articles: Adult Cardiac

On-Pump Versus Off-Pump Coronary Artery Bypass Grafting in a Cohort of 63,000 Patients

Danny Chu, MDa,*, Faisal G. Bakaeen, MDa, Tam K. Dao, PhDb, Scott A. LeMaire, MDa,c, Joseph S. Coselli, MDa,c, Joseph Huh, MDa,c

a Division of Cardiothoracic Surgery, Baylor College of Medicine, Houston, Texas
b Department of Psychiatry and Behavioral Sciences, Baylor College of Medicine, Houston, Texas
c Section of Adult Cardiac Surgery, The Texas Heart Institute at St. Luke's Episcopal Hospital, University of Houston, Houston, Texas

Accepted for publication March 17, 2009.

* Address correspondence to Dr Chu, Division of Cardiothoracic Surgery, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 (Email: dchumd{at}gmail.com).

Presented at the Forty-fifth Annual Meeting of The Society of Thoracic Surgeons, San Francisco, CA, Jan 26–28, 2009.


   Abstract
Top
 Abstract
Introduction
 Material and Methods
 Results
 Comment
 Discussion
 Acknowledgments
 References
 
Background: The best approach to surgical myocardial revascularization remains controversial. We compared outcomes of conventional on-pump coronary artery bypass grafting (CABG) and off-pump coronary artery bypass (OPCAB) by using a nonvoluntary national database.

Methods: In the 2004 Nationwide Inpatient Sample database, we identified 63,047 discharge records of patients who underwent CABG (n = 48,658) or OPCAB (n = 14,389). We analyzed seven preoperative variables, including the Deyo comorbidity index and five outcome measures. Multivariable logistic regression was used to identify independent predictors of outcomes.

Results: CABG and OPCAB patients had similar demographics and comorbidities. They also had similar rates of in-hospital mortality (3.0% vs 3.2%; p = 0.14) and postoperative stroke (1.8% vs 1.7%; p = 0.53). However, OPCAB patients had longer hospital stays (10.2 ± 9.4 vs 9.9 ± 8.5 days; p < 0.0001) and higher hospital costs ($38,793 ± $30,830 vs $37,806 ± $28,705; p = 0.0005) than CABG patients. Multivariable regression analysis showed that OPCAB independently predicted 0.6 more days of hospital stay (95% confidence interval [CI], 0.4 to 0.8 day; R 2 = 0.09; p < 0.0001) and $1,497 more in hospital costs (95% CI, $779 to $2,216; R 2 = 0.09; p < 0.01) per patient.

Conclusions: OPCAB does not produce lower postoperative mortality or stroke rates than CABG. Furthermore, OPCAB is associated with longer hospital stays and higher hospital costs.


   Introduction
Top
 Abstract
 Introduction
Material and Methods
 Results
 Comment
 Discussion
 Acknowledgments
 References
 
More than 13 million people in the United States have coronary artery disease [1]. Many of these people have multivessel disease, which is best treated with coronary artery bypass grafting (CABG) [2]. Thus, CABG is the most commonly performed procedure for cardiac surgeons. More than 150,000 CABG operations have been performed annually nationwide since the 1990s [3]. Traditionally, CABG procedures have been done with cardiopulmonary bypass (CPB).

Several physiologic derangements are associated with CPB, including thrombocytopenia, activation of complement factors, immune suppression, and inflammatory responses [4]. Furthermore, manipulating an atherosclerotic ascending aorta during cannulation and cross-clamping can potentially induce distal embolus formation, causing strokes. In an attempt to prevent CPB-related morbidity and minimize ascending aorta manipulation during surgical myocardial revascularization, surgeons developed off-pump coronary artery bypass (OPCAB), a revascularization technique that does not require CPB [5–9].

Such techniques were first introduced in the late 1960s [8] but have recently become more popular [10–13]. Proponents of OPCAB argue that all surgical myocardial revascularizations should be performed without the use of CPB. However, concerns that the technical difficulty of OPCAB compromises patient outcomes have kept some surgeons from using OPCAB routinely. As a result, numerous studies have been performed in an effort to address these issues.

Researchers have associated OPCAB with similar completeness of revascularization, similar early outcomes, shorter length of hospital stay, reduced transfusion requirements, reduced pulmonary morbidity, and fewer postoperative neurologic events compared with conventional CABG [8, 14–18]. Puskas and colleagues [19] report that 1-year graft patency and cost of hospitalization are similar in CABG and OPCAB patients. These authors have also associated OPCAB with both improved early outcomes and similar long-term survival compared with CABG in more than 12,000 patients [20].

In contrast, a randomized study by Khan and colleagues [21] found that graft patency rates 3 months postoperatively were significantly lower in OPCAB patients than in CABG patients. Likewise, Sabik and colleagues [22] at Cleveland Clinic found less complete revascularization in OPCAB patients compared retrospectively with CABG patients. Numerous other studies have not detected a notable difference between OPCAB and CABG techniques in early mortality, morbidity, or hospitalization costs [23–26]. Furthermore, a large meta-analysis by Marasco and colleagues [27] found no significant neurocognitive benefits of OPCAB vs CABG.

Which approach is best for surgical myocardial revascularization is controversial. The aim of our study was to compare CABG and OPCAB outcomes by analyzing data from a large, nonvoluntary national database.


   Material and Methods
Top
 Abstract
 Introduction
 Material and Methods
Results
 Comment
 Discussion
 Acknowledgments
 References
 
Data Source
Data were collected from the 2004 Nationwide Inpatient Sample (NIS), a database of hospital inpatient stays maintained by the Agency for Healthcare Research and Quality as part of the Healthcare Cost and Utilization Project (HCUP) [28]. The NIS is the largest all-payer inpatient care database, representing 20% of all hospital discharges from nonfederal facilities within the United States. The NIS has numerous internal quality assurance procedures that check the consistency and validity of data points (http://www.hcup-us.ahrq.gov/db/quality.jsp). Furthermore, HCUP validates the NIS annually by comparing its contents with those of two similar databases, the National Hospital Discharge Survey (NHDS) and the Medicare Provider Analysis and Review (MedPAR), to assess potential biases in the data set (http://www.hcup-us.ahrq.gov/db/nation/nis/nisrelatedreports.jsp).

The NIS contains data on approximately 8 million hospital stays each year from more than 1000 hospitals. Weights based on sampling probabilities for each stratum are used in the analysis to ensure that the hospitals studied are representative of all United States hospitals. Five hospital sampling strata were defined according to hospital characteristics contained in the American Hospital Association (AHA) Annual Survey of Hospitals. The stratification variables were geographic region, location (urban or rural), teaching status, control (public or proprietary), and bed size. Variables available in the NIS database include patient and hospital demographics, payer information, treating and concomitant diagnoses, in-patient procedures, in-hospital mortality, length of hospital stay (date of admission to date of discharge), overall hospitalization charges, and cost/charge ratios.

This study was approved by the Institutional Review Board of Baylor College of Medicine. The reported data conform to the data use agreement for the NIS from the HCUP. Additional information about NIS is available from the Agency for Healthcare Research and Quality (http://www.hcup-us.ahrq.gov/nisoverview.jsp).

Patient Selection
We used the 2003 International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis and procedure codes [29] to query the 2004 NIS database for our patient selection. The ICD-9 procedure codes 3610, 3611, 3612, 3613, 3614, 3615, and 3616 were used to identify CABG patients. We excluded patients who underwent concomitant cardiac procedures with the ICD-9 procedure codes listed in Appendix 1.


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  		Appendix 1 Exclusion Criteria
 
We found 63,047 discharge records of patients who underwent isolated CABG. Of these records, 48,658 were identified by the presence of ICD-9 procedure code 3961 (extracorporeal circulation) or 3966 (per CPB) as the records of patients who underwent conventional CABG with CPB. The other 14,389 records, which lacked procedure codes 3961 and 3966, were identified as the records of patients who underwent OPCAB.

Patient Characteristics
The Deyo index, a weighted comorbidity index modified from the Charlson comorbidity index, with a 0 to 3 scale (3 indicating greatest comorbidity) was used to compare preoperative morbidity in the two groups [30]. Deyo index scores were determined by weighted scoring of comorbidities and risk factors for perioperative complications, including cardiac, vascular, pulmonary, neurologic, endocrine, renal, hepatic, gastrointestinal, and immune diseases, and any documented history of cancer. The Deyo index consists of 17 prespecified comorbidities and is specifically designed to be used with administrative databases, using more than 600 ICD-9 diagnosis codes to query specific comorbid diagnoses [30]. Patient comorbidities were identified from each patient's ICD-9 diagnosis codes, of which 15 were recorded per patient in the NIS database. These codes were then used to produce a summary Deyo index score for each patient.

Study End Points
The primary end point of this study was in-hospital mortality. The secondary end points included postoperative stroke, length of hospital stay, rates of routine discharge, and overall hospitalization costs. The incidence of postoperative stroke was queried by using the ICD-9 diagnosis codes listed in Appendix 2.


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  		Appendix 2 Postoperative Stroke Criteria
 
Statistical Analysis
Statistical analysis was performed with SPSS 16.0 software (SPSS, Inc., Chicago, IL). Discharge weights were used to produce national estimates for all analyses. The t test and {chi}2 statistics were computed to examine intergroup differences in age, hospital length of stay, hospitalization cost, sex, race, income, expected payer, admission type, mortality, disposition of patient, postoperative stroke, and Deyo index score. After univariate analysis, multivariable analysis with hierarchical multiple regression and logistic regression methods was performed. Hierarchic multiple regression analysis was used to predict length of stay and total hospitalization cost after adjustment for age, sex, ethnicity, income, expected payer, admission type, and Deyo index score [30]. Hierarchic logistic regression analysis was used to examine the risk-adjusted association between type of procedure and mortality, disposition of patients, and postoperative stroke. In these analyses, there were two data entry blocks in the hierarchy. Covariates were evaluated in the first block, and the type of procedure was evaluated in the second block. To assess whether type of procedure predicted length of stay, mortality, postoperative stroke, and disposition of patients, the Nagelkerke R 2 was used. The Nagelkerke R 2 is the most frequently reported of the R 2 estimates computed during logistic regression [31].

Three different effect size statistics were computed for this study to assess the practical implications of our large sample size. Cohen's d was calculated for continuous data by using pooled standard deviations and was appropriately weighted for unequal sample size [32]. The {Phi} coefficient was computed for {chi}2 tests for independence with 1 df. Cramer's V was computed for variables with more than 1 df [32, 33]. We used the following categories to judge the computed effect sizes: less than 0.32 (small), 0.33 to 0.55 (medium), and more than 0.56 (large).


   Results
Top
 Abstract
 Introduction
 Material and Methods
 Results
Comment
 Discussion
 Acknowledgments
 References
 
Patient Characteristics and Outcome Measures
The two groups of patients did not differ significantly in terms of demographics and comorbidities (Table 1).


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  		Table 1 Patient Demographics and Comorbidities
 
The primary end point, the in-hospital mortality rate, was similar between the CABG and OPCAB patients (3.0% vs 3.2%), as were the incidence of postoperative stroke and the rate of routine discharge (Table 2). However, OPCAB patients had longer hospital stays and greater overall hospitalization costs.


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  		Table 2 Primary and Secondary End Points
 
After controlling for potential confounding variables (Table 1), multivariable analysis with logistic regression showed that OPCAB independently predicted 0.6 more days of hospital stay (95% confidence interval [CI], 0.4 to 0.8; R 2 = 0.09; p < 0.0001) and $1,497 more in overall hospitalization costs (95% CI, $779 to $2,216; R 2 = 0.09; p < 0.01) per patient than CABG (Table 3).


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  		Table 3 Multivariable Analysis of Outcome Measures Relative to OPCAB
 

   Comment
Top
 Abstract
 Introduction
 Material and Methods
 Results
 Comment
Discussion
 Acknowledgments
 References
 
Outcomes of surgical myocardial revascularization have improved during the last decade [34]. Advances in myocardial preservation and CPB have allowed cardiac surgeons to perform conventional CABG with CPB safely and effectively [35, 36]. Nevertheless, OPCAB has emerged as an alternative approach with the potential advantages of reducing early mortality and morbidity while producing long-term outcomes equivalent to those of CABG. OPCAB has slowly gained popularity in the last decade; in 2002, approximately 20% of surgical coronary revascularization procedures were OPCABs [19]. Despite the relatively low frequency of OPCAB in the United States, some cardiac surgeons routinely offer OPCAB to all patients who are candidates for surgical myocardial revascularization because of its potential advantages over CABG.

These advantages have been shown in numerous published studies from well-respected institutions, including studies that have used the national Society of Thoracic Surgeons database [8, 14–20, 37]. However, most of these studies have involved single-institution or voluntary national databases. The nature of the voluntary database can potentially cause reporting bias; institutions with less-than-perfect outcomes are unlikely to voluntarily report their data or publicly advertise them in a research forum [38]. Furthermore, most of the single-institution studies have been conducted at centers of excellence by cardiac surgical teams intimately familiar with the intricate technical nuances of OPCAB. For this reason, outcomes of OPCAB in these centers of excellence have been as good as or better than those of CABG.

Our study, in contrast, provides insight into real-world outcomes of OPCAB vs CABG because it used a nonvoluntary nationwide database, thus eliminating such bias. We were unable to detect any significant differences in rates of in-hospital mortality and incidences of postoperative stroke between OPCAB and CABG patients. Furthermore, our study showed that OPCAB independently predicted increased length of hospital stay and overall hospitalization cost after adjustment for potential confounding factors.

With the advent of drug-eluting stents, the overall CABG volume has declined steadily across the country in the past several years [39]. In an attempt to compete for more cases, some surgeons or practices that lack an experienced support team routinely use OPCAB to market themselves to the public by touting the potential benefits of OPCAB. Without an experienced support team and surgeon, OPCAB can lead to increased mortality and morbidity when emergency conversion to CABG is required because of technical mishaps [40]. This problem may explain why, in our study, OPCAB did not improve early outcomes compared with CABG, yet it independently predicted increased length of stay and hospitalization costs.

In addition, performing OPCAB in all patients who are candidates for surgical myocardial revascularization for the sole purpose of attracting more patients may not be appropriate. Patients with small targets, significant atherosclerotic burden in the coronary artery, or intramyocardial coronary artery targets may not be suitable for OPCAB if inexperienced operators perform the procedure. Occasionally, the referring cardiologists or the patients themselves insist on OPCAB. The decision to proceed with OPCAB in these patients is a delicate balance between handling the pressure to compete for more CABG cases and providing sound surgical care. Unfortunately, because of the declining CABG volume, good surgical judgment sometimes loses out to political and economic pressures, potentially affecting patient outcomes by biasing patient selection. Such biases may explain our finding that OPCAB was associated with a greater length of hospital stay and higher hospital costs per patient than CABG. Although these increases were relatively small, their cumulative effect was substantial: more than $1.4 million would have been saved, without compromising early outcomes, for every 1000 patients who had undergone CABG instead of OPCAB.

Our study is subject to the limitations inherent in a retrospective review:

• There may have been selection bias in terms of whether CABG or OPCAB was chosen for a given patient. Despite this possible bias, the preoperative demographics and baseline comorbidities of the two groups of patients did not differ significantly. Furthermore, we were able to control for confounding factors by using multivariable analysis to show the independent effects of OPCAB on prespecified outcomes.
• Because of the administrative nature of the NIS database, we were not able to obtain data from detailed neurologic examinations to compare stroke rates between the groups of patients.
• Our data represent a snapshot of real-world surgical practice in 2004 and may not be representative of current CABG practice because of advances in the technology and techniques used in OPCAB procedures.
• Because we did not use intent-to-treat analysis, OPCAB patients who converted to on-pump CABG were classified as conventional CABG patients. This may have biased our results against conventional CABG because patients who are converted from OPCAB to CABG tend have poorer outcomes than other CABG patients.
• The length of hospital stay in our study was defined as the time from the date of admission to the date of discharge. As a result, we were unable to specifically identify postoperative lengths of hospital stay because the NIS database does not capture specific dates of the operation.
• The Deyo comorbidity index does not capture variables such as the presence of aortic atheroma or concomitant antiplatelet therapy. Therefore, when used for risk stratification, the Deyo comorbidity index may not reflect all of the important aspects of the clinical scenario.
• Because the NIS database is administrative in nature, there may have been reporting bias due to coding errors. However, such a bias would have affected the two groups of patients equally. Nonetheless, because of this potential coding bias, we decided to limit our outcome measures mostly to concrete end points such as mortality, hospitalization costs, and length of stay.

Using the NIS has certain advantages. In additional to being nonvoluntary, which eliminates institutional and surgeon bias, this nationwide database provides an enormous sample size, which allows adequate power when one is attempting to detect low-frequency outcome measures such as mortality rates. Using more than 63,000 discharge records from the 2004 NIS database, we found no significant difference in the incidence of postoperative stroke or in-hospital mortality between OPCAB and CABG patients. Despite the similar early outcomes, OPCAB was independently associated with small but significant increases in length of hospital stay and overall hospitalization costs. Given that more than 150,000 CABG procedures are performed in the United States annually [3], the small increase in hospitalization cost incurred by OPCAB translates to an enormous health care burden on an already strained economy.

Our findings and a large body of other published studies leave little doubt that OPCAB and CABG yield equivalent early, and perhaps long-term, outcomes. Contrary to other studies, our study of NIS data did not associate OPCAB with postoperative stroke reduction or decreased length of hospital stay. We hope that our findings will reduce bias against conventional CABG among patients and referring cardiologists. Conventional CABG with CPB is a time-proven, effective, and safe procedure. However, CABG can be prohibitively risky when a severely diseased ascending aorta is encountered. In this scenario, we believe OPCAB provides an excellent approach to surgical myocardial revascularization.

As shown by numerous studies, OPCAB may produce better results when performed in experienced centers of excellence with a dedicated team approach [8, 15, 16, 19, 20]. Given our findings, however, we believe that OPCAB should be a part of every cardiac surgeon's repertoire as an alternative to—not a replacement for—conventional CABG with CPB. Our study serves as a hypothesis-generating argument for future prospective trials with an emphasis on cost to address the cost-effectiveness issue between conventional CABG and OPCAB.


   Appendix
 


   Discussion
Top
 Abstract
 Introduction
 Material and Methods
 Results
 Comment
 Discussion
Acknowledgments
 References
 
DR JOHN PUSKAS (Atlanta, GA): Good morning, President Chitwood, Secretary Wood, members, and guests. I read with interest the manuscript by Chu and colleagues from Houston. These investigators chose to analyze data from the 2004 Nationwide Inpatient Sample (NIS) database to compare major adverse events, length of stay, and cost among 63,000 nonrandomized, nonconsecutive coronary surgery patients who had either off-pump or on-pump coronary bypass performed. They adjusted risk between these two different patient groups by performing multivariable logistic regression with the only seven preoperative variables available to them and report that off-pump and on-pump coronary bypass are associated with similar incidence of death, stroke, and discharge to home. Off-pump in their study was found to predict a longer length of stay by approximately half a day and a higher cost by approximately $1,500. The authors conclude that, "Performing off-pump bypass in all candidates for surgical revascularization may not be justifiable." In my opinion, it is that conclusion which cannot be justified.

My brief argument is limited to three slides and will be in two parts. First, I would like to reiterate the very solid evidence from The Society of Thoracic Surgeons (STS) national database, which shows reduced adjusted risk of death, stroke, myocardial infarction (MI), major adverse cardiovascular event (MACE), prolonged length of stay, and numerous other negative or adverse effects for off-pump bypass compared to on-pump bypass, and second, to again point out some of the many deficiencies of administrative databases and the dangers inherent in trying to analyze such administrative databases for the purpose of clinical guidance and clinical outcomes analysis.

This slide you see shows the abstract of the Chamberlain Award paper in 2007, which derived from a sample of the national STS database. In brief, this sample examined patients having off-pump vs on-pump bypass in the year 2004 and 2005. There were 42,000 such patients. Because of the richness and completeness of the STS-audited database, which were able to risk-adjust these two patient cohorts for 32 clinical risk factors, and comparing between off-pump and on-pump, we found that the risk of death was reduced by approximately 17%, or an odds ratio of 0.83, risk of stroke reduced by 35%, an odds ratio of 0.65, and you see the other number there, MI reduced by 33%, MACE by 29%, and prolonged length of stay incidence reduced by 30%. You see the 95% confidence intervals there and the p values. These are very tight data, and they are compelling. This is the most sophisticated and complete risk-adjusted assessment possible with a very vigorous database.

By comparison, the administrative database used in the Chu paper used seven risk factors, of which only four were clinical risk factors. Others included race, family income, and identity of the payer.

This slide shows a more recent updated analysis of the national STS database looking at patients of differing coronary anatomy, one- or two-vessel disease, three-vessel disease with left main or without left main, and you can see for stroke, MI, mortality, and MACE, all of the adjusted ratios for risk are in favor of off-pump bypass.

Finally, I would like to draw your attention to this paper by our Second Vice President, Michael Mack, comparing the relative merits of administrative databases vs the national STS database. It is worthy of review. And interestingly, this study found that there was substantial variability in reported outcomes in the administrative databases, and in particular, the risk adjustment algorithms available in those limited databases could err in assessing risk-adjusted mortality by as much as 61%.

So in conclusion, I would like to ask Dr Chu, does he feel that adjusting for four clinical variables is an adequate risk adjustment of an administrative database in order to make clinical recommendations? Number two, I have not been able to find another comparison of surgical technique in cardiac surgery based on such a limited risk adjustment or the use of the Deyo risk index, and I wonder if he has. Finally, I noticed that there was a 5% difference in the incidence of emergency cases, more being in the off-pump cases in his data sample, and that there were several newborns included in this analysis of coronary bypass surgery. I think those things illustrate some of the deficiencies of this limited data set. Thank you.

DR CHU: Thank you very much, Dr Puskas. It is truly an honor to have someone with your stature to discuss my paper. Admittedly so, there is no perfect database. Let me begin by addressing your first question regarding the use of only four clinical variables. The Deyo comorbidity index, perhaps I should be more thorough in my manuscript, actually comprises 17 different types of associated comorbidities, including history of myocardial infarction, congestive heart failure, peripheral vascular disease, cerebrovascular disease, and comprises over 600 International Classification of Diseases, Ninth Revision (ICD-9) diagnosis codes in order to capture and stratify these patients. The Deyo comorbidity index is a modification of the Charlson comorbidity index, which has been published for the last 10 years and validated in over 500 manuscripts in the academic community. Specifically, recently, there was a large study published in the Journal of the American College of Surgeons comparing transhiatal esophagectomy vs Ivor-Lewis esophagectomy. It is the largest study comparing the outcomes of those two types of procedures.

I agree with you that there are coding and reporting biases with this database. Specifically, I noted that there were five newborn admission types coded in over 63,000 patients. Clearly, that is erroneous, and for our final manuscript we are going to delete 5 patients out of over 63,000 cohorts. And specifically, the 5 patients were somewhat equally distributed between the two groups of patients. These coding biases and reporting biases should be statistically distributed equally between the two groups of patients as shown here since the individuals responsible for coding were blinded to our study.

Again, I appreciate Dr Puskas in taking the time to review our manuscript, and I would like to say that we do not believe that performing off-pump CABG in all patients is justifiable; however, there are certain clinical scenarios that necessitate the use of OPCAB technique such as severely calcified ascending aorta. In this scenario, centers of excellence in OPCAB that are performing these operations with clinical pathways and infrastructure supporting these patients are likely able to generate excellent outcomes.

Thank you very much.


   Acknowledgments
Top
 Abstract
 Introduction
 Material and Methods
 Results
 Comment
 Discussion
 Acknowledgments
References
 
We thank Stephen N. Palmer, PhD, ELS, for his editorial assistance in the preparation of this manuscript.


   References
Top
 Abstract
 Introduction
 Material and Methods
 Results
 Comment
 Discussion
 Acknowledgments
 References
 

  1. Morrow DA, Gersh BJ. Chronic coronary artery diseaseIn: Libby P, Braunwald E, editors. Braunwald's heart disease: a textbook of cardiovascular medicine. Philadelphia: Saunders/Elsevier; 2008. pp. 1353-1417.
  2. Niles NW, McGrath PD, Malenka D, et al. Survival of patients with diabetes and multivessel coronary artery disease after surgical or percutaneous coronary revascularization: results of a large regional prospective study. Northern New England Cardiovascular Disease Study Group. J Am Coll Cardiol 2001;37:1008-1015.[Abstract/Free Full Text]
  3. Wilson CT, Fisher ES, Welch HG, Siewers AE, Lucas FL. U.S. trends in CABG hospital volume: the effect of adding cardiac surgery programs Health Aff (Millwood) 2007;26:162-168.[Abstract/Free Full Text]
  4. Edmunds Jr LH, Hessel 2nd EA, Colman RW, Menasche P, Hammon Jr JW. Extracorporeal circulationIn: Cohn LH, Edmunds LH, editors. Cardiac surgery in the adult. New York: McGraw-Hill, Medical Pub Division; 2003. pp. 315-387.
  5. Dewey TM, Magee MJ, Edgerton JR, Mathison M, Tennison D, Mack MJ. Off-pump bypass grafting is safe in patients with left main coronary disease Ann Thorac Surg 2001;72:788-791discussion 92.[Abstract/Free Full Text]
  6. Güler M, Kirali K, Toker ME, et al. Different CABG methods in patients with chronic obstructive pulmonary disease Ann Thorac Surg 2001;71:152-157.[Abstract/Free Full Text]
  7. Magee MJ, Dewey TM, Acuff T, et al. Influence of diabetes on mortality and morbidity: off-pump coronary artery bypass grafting versus coronary artery bypass grafting with cardiopulmonary bypass Ann Thorac Surg 2001;72:776-780discussion 80–1.[Abstract/Free Full Text]
  8. Puskas JD, Wright CE, Ronson RS, Brown 3rd WM, Gott JP, Guyton RA. Off-pump multivessel coronary bypass via sternotomy is safe and effective Ann Thorac Surg 1998;66:1068-1072.[Abstract/Free Full Text]
  9. Trehan N, Mishra M, Sharma OP, Mishra A, Kasliwal RR. Further reduction in stroke after off-pump coronary artery bypass grafting: a 10-year experience Ann Thorac Surg 2001;72:S1026-S1032.[Abstract/Free Full Text]
  10. Benetti FJ, Ballester C, Sani G, Doonstra P, Grandjean J. Video assisted coronary bypass surgery J Card Surg 1995;10:620-625.[Medline]
  11. Buffolo E, de Andrade CS, Branco JN, Teles CA, Aguiar LF, Gomes WJ. Coronary artery bypass grafting without cardiopulmonary bypass Ann Thorac Surg 1996;61:63-66.[Abstract/Free Full Text]
  12. Calafiore AM, Angelini GD, Bergsland J, Salerno TA. Minimally invasive coronary artery bypass grafting Ann Thorac Surg 1996;62:1545-1548.[Abstract/Free Full Text]
  13. Guru V, Glasgow KW, Fremes SE, Austin PC, Teoh K, Tu JV. The real-world outcomes of off-pump coronary artery bypass surgery in a public health care system Can J Cardiol 2007;23:281-286.[Medline]
  14. Halkos ME, Puskas JD, Lattouf OM, Kilgo P, Guyton RA, Thourani VH. Impact of preoperative neurologic events on outcomes after coronary artery bypass grafting Ann Thorac Surg 2008;86:504-510discussion 10.[Abstract/Free Full Text]
  15. Puskas JD, Thourani VH, Marshall JJ, et al. Clinical outcomes, angiographic patency, and resource utilization in 200 consecutive off-pump coronary bypass patients Ann Thorac Surg 2001;71:1477-1483discussion 83–4.[Abstract/Free Full Text]
  16. Puskas JD, Williams WH, Duke PG, et al. Off-pump coronary artery bypass grafting provides complete revascularization with reduced myocardial injury, transfusion requirements, and length of stay: a prospective randomized comparison of two hundred unselected patients undergoing off-pump versus conventional coronary artery bypass grafting J Thorac Cardiovasc Surg 2003;125:797-808.[Abstract/Free Full Text]
  17. Sedrakyan A, Wu AW, Parashar A, Bass EB, Treasure T. Off-pump surgery is associated with reduced occurrence of stroke and other morbidity as compared with traditional coronary artery bypass grafting: a meta-analysis of systematically reviewed trials Stroke 2006;37:2759-2769.[Free Full Text]
  18. Staton GW, Williams WH, Mahoney EM, et al. Pulmonary outcomes of off-pump vs on-pump coronary artery bypass surgery in a randomized trial Chest 2005;127:892-901.[Abstract/Free Full Text]
  19. Puskas JD, Williams WH, Mahoney EM, et al. Off-pump vs conventional coronary artery bypass grafting: early and 1-year graft patency, cost, and quality-of-life outcomes: a randomized trial JAMA 2004;291:1841-1849.[Abstract/Free Full Text]
  20. Puskas JD, Kilgo PD, Lattouf OM, et al. Off-pump coronary bypass provides reduced mortality and morbidity and equivalent 10-year survival Ann Thorac Surg 2008;86:1139-1146discussion 46.[Abstract/Free Full Text]
  21. Khan NE, De Souza A, Mister R, et al. A randomized comparison of off-pump and on-pump multivessel coronary-artery bypass surgery N Engl J Med 2004;350:21-28.[Medline]
  22. Sabik JF, Gillinov AM, Blackstone EH, et al. Does off-pump coronary surgery reduce morbidity and mortality? J Thorac Cardiovasc Surg 2002;124:698-707.[Abstract/Free Full Text]
  23. Bull DA, Neumayer LA, Stringham JC, Meldrum P, Affleck DG, Karwande SV. Coronary artery bypass grafting with cardiopulmonary bypass versus off-pump cardiopulmonary bypass grafting: does eliminating the pump reduce morbidity and cost? Ann Thorac Surg 2001;71:170-173discussion 3–5.[Abstract/Free Full Text]
  24. Cheng DC, Bainbridge D, Martin JE, Novick RJ. Does off-pump coronary artery bypass reduce mortality, morbidity, and resource utilization when compared with conventional coronary artery bypass?. A meta-analysis of randomized trials. Anesthesiology 2005;102:188-203.[Medline]
  25. Cheng W, Denton TA, Fontana GP, et al. Off-pump coronary surgery: effect on early mortality and stroke J Thorac Cardiovasc Surg 2002;124:313-320.[Abstract/Free Full Text]
  26. Takagi H, Tanabashi T, Kawai N, Umemoto T. Off-pump surgery does not reduce stroke, compared with results of on-pump coronary artery bypass grafting: a meta-analysis of randomized clinical trials J Thorac Cardiovasc Surg 2007;134:1059-1060.[Free Full Text]
  27. Marasco SF, Sharwood LN, Abramson MJ. No improvement in neurocognitive outcomes after off-pump versus on-pump coronary revascularisation: a meta-analysis Eur J Cardiothorac Surg 2008;33:961-970.[Abstract/Free Full Text]
  28. Healthcare Cost Utilization Project, Nationwide Inpatient Sample (NIS)Rockville, MD: Agency for Healthcare Research and Quality; 2001.
  29. International classification of diseases, ninth revision, clinical modification, fifth editionWashington, DC: U.S. Dept. of Health and Human Services, Public Health Service; 1988.
  30. Deyo RA, Cherkin DC, Ciol MA. Adapting a clinical comorbidity index for use with ICD-9-CM administrative databases J Clin Epidemiol 1992;45:613-619.[Medline]
  31. Nagelkerke NJD. A note on a general definition of the coefficient of determination Biometrika 1991;78:691-692.[Abstract/Free Full Text]
  32. Cohen J. Statistical power analysis for the behavioral sciencesHillsdale, NJ: L. Erlbaum Associates; 1988.
  33. Lipsey MW. Design sensitivity: statistical power for experimental researchNewbury Park, CA: Sage Publications; 1990.
  34. Ghali WA, Quan H, Shrive FM, Hirsch GM. Outcomes after coronary artery bypass graft surgery in Canada: 1992/93 to 2000/01 Can J Cardiol 2003;19:774-781.[Medline]
  35. Lazar HL. Enhanced preservation of acutely ischemic myocardium and improved clinical outcomes using glucose-insulin-potassium (GIK) solutions Am J Cardiol 1997;80:90A-93A.[Medline]
  36. Rinne T, Pehkonen E, Kaukinen S, Tarkka M. Comparison of cardioprotection with crystalloid and blood cardioplegia in CABG patients J Cardiothorac Vasc Anesth 1993;7:679-683.[Medline]
  37. Cleveland Jr JC, Shroyer AL, Chen AY, Peterson E, Grover FL. Off-pump coronary artery bypass grafting decreases risk-adjusted mortality and morbidity Ann Thorac Surg 2001;72:1282-1288discussion 1288–9.[Abstract/Free Full Text]
  38. Welke KF, Diggs BS, Karamlou T, Ungerleider RM. Comparison of pediatric cardiac surgical mortality rates from national administrative data to contemporary clinical standards Ann Thorac Surg 2009;87:216-222discussion 222–3.[Abstract/Free Full Text]
  39. Mack MJ, Brown PP, Kugelmass AD, et al. Current status and outcomes of coronary revascularization 1999 to 2002: 148,396 surgical and percutaneous procedures Ann Thorac Surg 2004;77:761-766discussion 766–8.[Abstract/Free Full Text]
  40. Jin R, Hiratzka LF, Grunkemeier GL, Krause A, Page 3rd US. Aborted off-pump coronary artery bypass patients have much worse outcomes than on-pump or successful off-pump patients Circulation 2005;112:I332-I337.[Medline]



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