Related Experiment Video
Updated: Jun 23, 2026
Surgical Porcine Model of Chronic Myocardial Ischemia Treated by Exosome-laden Collagen Patch and Off-pump Coronary Artery Bypass Graft
Published on: September 15, 2023
Surgical volume and outcomes of off-pump coronary artery bypass graft surgery: Does it matter?
Suma H Konety1, Gary E Rosenthal, Mary S Vaughan-Sarrazin
1Division of Cardiovascular Diseases, Department of Internal Medicine, University of California San Francisco, San Francisco, Calif., USA. konetys@medicine.ucsf.edu
Insights
Off-pump coronary artery bypass grafting (CABG) shows better outcomes than on-pump CABG, especially in high-volume hospitals. Increased use of off-pump CABG correlates with improved patient results, indicating its safe implementation.
Area of Science:
- Cardiovascular Surgery
- Health Services Research
Background:
- Off-pump coronary artery bypass grafting (OPCAB) is a less morbid alternative to on-pump CABG.
- The influence of hospital volume on OPCAB outcomes compared to on-pump CABG remains unevaluated.
Purpose of the Study:
- To evaluate the impact of hospital volume on the outcomes of off-pump versus on-pump coronary artery bypass grafting.
Main Methods:
- Retrospective analysis of 125,355 patients undergoing CABG (2000-2004) in California.
- Comparison of in-hospital mortality and postoperative complications using generalized linear mixed models.
- Evaluation of outcomes across hospital volume quartiles for off-pump versus on-pump procedures.
Main Results:
- Off-pump CABG was associated with a shorter length of stay and lower unadjusted mortality and complication rates.
- In high-volume hospitals, off-pump CABG showed significantly lower adjusted mortality and complication rates compared to on-pump CABG.
- In low-volume hospitals, no significant difference in mortality or complications was observed between off-pump and on-pump CABG.
Conclusions:
- Off-pump CABG offers superior outcomes compared to on-pump CABG.
- The benefits of off-pump CABG increase with higher relative hospital utilization of the procedure.
- Off-pump CABG can be safely performed across a wide range of hospitals.
Objectives:
Coronary artery bypass grafting performed off-pump has emerged in recent years as a less morbid alternative to on-pump bypass grafting. However, the impact of hospital volume on the outcomes of off-pump relative to on-pump bypass grafting has not been evaluated.
Methods:
We conducted a retrospective study of patients undergoing off-pump (n = 26,011) and on-pump (n = 99,344) coronary artery bypass grafting during 2000 through 2004 in 124 California hospitals, using the California Patient Discharge Database. Generalized linear mixed models were used to compare in-hospital mortality and postoperative complications in patients undergoing on-pump versus off-pump bypass grafting, accounting sequentially for differences in patient characteristics and hospital-level effects. The relative mortality and complication rates for patients undergoing on-pump versus off-pump coronary bypass were evaluated across hospital volume quartiles.
Results:
Mean length of stay was lower for patients who underwent off-pump compared with on-pump bypass grafting (8.7 vs 9.6 days; P < .001), as were unadjusted mortality and complication rates (2.2% vs 3.3%; 10.1% vs 11.6%, respectively; P < .001). For hospitals in the highest percent off-pump bypass quartile, adjusted mortality and complication rates for patients having off-pump bypass were significantly lower than for the on-pump group (odds ratio [OR] = 0.50; 95% confidence intervals [CI], 0.41-0.61; OR = 0.73; 95% CI, 0.66-0.81, respectively; P < .001); by contrast, for hospitals in the lowest percent off-pump bypass quartile, mortality and complications were similar in off-pump and on-pump groups (OR = 1.10; 95% CI, 0.75-1.63; OR = 0.92; 95% CI, 0.72-1.16, respectively; P > .05).
Conclusions:
Outcomes were significantly better for off-pump compared with on-pump coronary artery bypass grafting. Although the benefit of off-pump bypass grafting increased as the relative use of the procedure at a hospital increased, off-pump bypass grafting can be safely implemented across numerous hospitals.
Related Concept Videos
01:23Peripheral Artery Disease V: Postoperative Nursing Management
01:22Cardiac Output II: Effect of Stroke Volume on Cardiac Output
Preload
Preload refers to the initial elongation of the cardiac myocytes before contraction and is related to the volume of blood filling the heart at the end of diastole, or end-diastolic volume. The...
01:11Cardiac Output and Stroke Volume
In an average resting adult male, the typical cardiac output averages...
01:28Cardiomyopathy VII: Pre and Post Operative Nursing Management