Off-Pump coronary artery bypass surgery is associated with worse arterial and saphenous vein graft patency and less effective revascularization: Results from the Veterans Affairs Randomized On/Off Bypass (ROOBY) trial

BACKGROUND

The Department of Veterans Affairs Randomized On/Off Bypass (ROOBY) trial compared clinical and angiographic outcomes in off-pump versus on-pump coronary artery bypass graft (CABG) surgery to ascertain the relative efficacy of the 2 techniques.

METHODS AND RESULTS

From February 2002 to May 2007, the ROOBY trial randomized 2203 patients to off-pump versus on-pump CABG. Follow-up angiography was obtained in 685 off-pump (62%) and 685 on-pump (62%) patients. Angiograms were analyzed (blinded to treatment) for FitzGibbon classification (A=widely patent, B=flow limited, O=occluded) and effective revascularization. Effective revascularization was defined as follows: All 3 major coronary territories with significant disease were revascularized by a FitzGibbon A-quality graft to the major diseased artery, and there were no new postanastomotic lesions. Off-pump CABG resulted in lower FitzGibbon A patency rates than on-pump CABG for arterial conduits (85.8% versus 91.4%; P=0.003) and saphenous vein grafts (72.7% versus 80.4%; P<0.001). Fewer off-pump patients were effectively revascularized (50.1% versus 63.9% on-pump; P<0.001). Within each major coronary territory, effective revascularization was worse off pump than on pump (all P≤0.001). The 1-year adverse cardiac event rate was 16.4% in patients with ineffective revascularization versus 5.9% in patients with effective revascularization (P<0.001).

CONCLUSIONS

Off-pump CABG resulted in significantly lower FitzGibbon A patency for arterial and saphenous vein graft conduits and less effective revascularization than on-pump CABG. At 1 year, patients with less effective revascularization had higher adverse event rates.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00032630.

ACCF/SCAI/STS/AATS/AHA/ASNC/HFSA/SCCT 2012 appropriate use criteria for coronary revascularization focused update: a report of the American College of Cardiology Foundation Appropriate Use Criteria Task Force, Society for Cardiovascular Angiography and Interventions, Society of Thoracic Surgeons, American Association for Thoracic Surgery, American Heart Association, American Society of Nuclear Cardiology, and the Society of Cardiovascular Computed Tomography

The American College of Cardiology Foundation (ACCF), Society for Cardiovascular Angiography and Interventions, Society of Thoracic Surgeons, and the American Association for Thoracic Surgery, along with key specialty and subspecialty societies, conducted an update of the appropriate use criteria (AUC) for coronary revascularization frequently considered. In the initial document, 180 clinical scenarios were developed to mimic patient presentations encountered in everyday practice and included information on symptom status, extent of medical therapy, risk level as assessed by noninvasive testing, and coronary anatomy. This update provides a reassessment of clinical scenarios the writing group felt to be affected by significant changes in the medical literature or gaps from prior criteria. The methodology used in this update is similar to the initial document, and the definition of appropriateness was unchanged. The technical panel scored the clinical scenarios on a scale of 1 to 9. Scores of 7 to 9 indicate that revascularization is considered appropriate and likely to improve patients' health outcomes or survival. Scores of 1 to 3 indicate revascularization is considered inappropriate and unlikely to improve health outcomes or survival. Scores in the mid-range (4 to 6) indicate a clinical scenario for which the likelihood that coronary revascularization will improve health outcomes or survival is uncertain. In general, as seen with the prior AUC, the use of coronary revascularization for patients with acute coronary syndromes and combinations of significant symptoms and/or ischemia is appropriate. In contrast, revascularization of asymptomatic patients or patients with low-risk findings on noninvasive testing and minimal medical therapy are viewed less favorably. The technical panel felt that based on recent studies, coronary artery bypass grafting remains an appropriate method of revascularization for patients with high burden of coronary artery disease (CAD). Additionally, percutaneous coronary intervention may have a role in revascularization of patients with high burden of CAD. The primary objective of the appropriate use criteria is to improve physician decision making and patient education regarding expected benefits from revascularization and to guide future research.

Comparative effectiveness of revascularization strategies

BACKGROUND

Questions persist concerning the comparative effectiveness of percutaneous coronary intervention (PCI) and coronary-artery bypass grafting (CABG). The American College of Cardiology Foundation (ACCF) and the Society of Thoracic Surgeons (STS) collaborated to compare the rates of long-term survival after PCI and CABG.

METHODS

We linked the ACCF National Cardiovascular Data Registry and the STS Adult Cardiac Surgery Database to claims data from the Centers for Medicare and Medicaid Services for the years 2004 through 2008. Outcomes were compared with the use of propensity scores and inverse-probability-weighting adjustment to reduce treatment-selection bias.

RESULTS

Among patients 65 years of age or older who had two-vessel or three-vessel coronary artery disease without acute myocardial infarction, 86,244 underwent CABG and 103,549 underwent PCI. The median follow-up period was 2.67 years. At 1 year, there was no significant difference in adjusted mortality between the groups (6.24% in the CABG group as compared with 6.55% in the PCI group; risk ratio, 0.95; 95% confidence interval [CI], 0.90 to 1.00). At 4 years, there was lower mortality with CABG than with PCI (16.4% vs. 20.8%; risk ratio, 0.79; 95% CI, 0.76 to 0.82). Similar results were noted in multiple subgroups and with the use of several different analytic methods. Residual confounding was assessed by means of a sensitivity analysis.

CONCLUSIONS

In this observational study, we found that, among older patients with multivessel coronary disease that did not require emergency treatment, there was a long-term survival advantage among patients who underwent CABG as compared with patients who underwent PCI. (Funded by the National Heart, Lung, and Blood Institute.).

Prediction of long-term mortality after percutaneous coronary intervention in older adults: results from the National Cardiovascular Data Registry

BACKGROUND

The purpose of this study was to develop a long-term model to predict mortality after percutaneous coronary intervention in both patients with ST-segment elevation myocardial infarction and those with more stable coronary disease.

METHODS AND RESULTS

The American College of Cardiology Foundation CathPCI Registry data were linked to the Centers for Medicare and Medicaid Services 100% denominator file by probabilistic matching. Preprocedure demographic and clinical variables from the CathPCI Registry were used to predict the probability of death over 3 years as recorded in the Centers for Medicare and Medicaid Services database. Between 2004 and 2007, 343 466 patients (66%) of 518 195 patients aged ≥65 years undergoing first percutaneous coronary intervention in the CathPCI Registry were successfully linked to Centers for Medicare and Medicaid Services data. This study population was randomly divided into 60% derivation and 40% validation cohorts. Median follow-up was 15 months, with mortality of 3.0% at 30 days and 8.7%, 13.4%, and 18.7% at 1, 2, and 3 years, respectively. Twenty-four characteristics related to demographics, clinical comorbidity, prior history of disease, and indices of disease severity and acuity were identified as being associated with mortality. The C indices in the validation cohorts for patients with and without ST-segment elevation myocardial infarction were 0.79 and 0.78. The model calibrated well across a wide range of predicted probabilities.

CONCLUSIONS

On the basis of the large and nationally representative CathPCI Registry, we have developed a model that has excellent discrimination, calibration, and validation to predict survival up to 3 years after percutaneous coronary intervention.

Predictors of long-term survival after coronary artery bypass grafting surgery: results from the Society of Thoracic Surgeons Adult Cardiac Surgery Database (the ASCERT study)

BACKGROUND

Most survival prediction models for coronary artery bypass grafting surgery are limited to in-hospital or 30-day end points. We estimate a long-term survival model using data from the Society of Thoracic Surgeons Adult Cardiac Surgery Database and Centers for Medicare and Medicaid Services.

METHODS AND RESULTS

The final study cohort included 348 341 isolated coronary artery bypass grafting patients aged ≥65 years, discharged between January 1, 2002, and December 31, 2007, from 917 Society of Thoracic Surgeons-participating hospitals, randomly divided into training (n=174 506) and validation (n=173 835) samples. Through linkage with Centers for Medicare and Medicaid Services claims data, we ascertained vital status from date of surgery through December 31, 2008 (1- to 6-year follow-up). Because the proportional hazards assumption was violated, we fit 4 Cox regression models conditional on being alive at the beginning of the following intervals: 0 to 30 days, 31 to 180 days, 181 days to 2 years, and >2 years. Kaplan-Meier-estimated mortality was 3.2% at 30 days, 6.4% at 180 days, 8.1% at 1 year, and 23.3% at 3 years of follow-up. Harrell's C statistic for predicting overall survival time was 0.732. Some risk factors (eg, emergency status, shock, reoperation) were strong predictors of short-term outcome but, for early survivors, became nonsignificant within 2 years. The adverse impact of some other risk factors (eg, dialysis-dependent renal failure, insulin-dependent diabetes mellitus) continued to increase.

CONCLUSIONS

Using clinical registry data and longitudinal claims data, we developed a long-term survival prediction model for isolated coronary artery bypass grafting. This provides valuable information for shared decision making, comparative effectiveness research, quality improvement, and provider profiling.

Predictors and impact of postoperative atrial fibrillation on patients' outcomes: a report from the Randomized On Versus Off Bypass trial

OBJECTIVE

The study objective was to determine the predictors of postoperative atrial fibrillation (POAF) in patients randomized to conventional coronary artery bypass graft (on-pump coronary artery bypass [ONCAB]) versus beating heart coronary surgery (off-pump coronary artery bypass [OPCAB]).

METHODS

The subgroup of 2103 patients (of 2203 enrollees) in the Randomized On Versus Off Bypass trial with no POAF was studied (1056 patients in the ONCAB group and 1047 patients in the OPCAB group). Univariate and multivariate analyses were used to identify the predictors of POAF and the impact of POAF on outcomes.

RESULTS

Use of ONCAB versus OPCAB was not associated with increased rates of POAF. Older age (P < .0001), white race (P < .001), and hypertension (P < .002) were predictors of POAF on multivariate analysis. In general, POAF led to a higher rates of reintubation (ONCAB: 6.3% vs 0.8% no POAF, P < .001; OPCAB: 7.4% vs 1.8% no POAF, P < .0001) and prolonged ventilatory support (ONCAB: 7.1% vs 2.3% no POAF, P = .001; OPCAB: 9.2% vs 3.4% no POAF, P = .0003). The rate of any early adverse outcome was higher in patients with POAF (all patients: 10% POAF vs 4.7% no POAF, P < .0001; ONCAB: 9% POAF vs 4.3% no POAF, P = .008; OPCAB: 11% POAF vs 5.1% no POAF, P = .001). The 1-year all cause mortality was higher with POAF for both groups (ONCAB: 5.4% POAF vs 2% no POAF, P = .009; OPCAB: 5.1% POAF vs 2.6% no POAF, P = .07). POAF was independently associated with early composite end point (odds ratio [OR], 2.23; confidence interval [CI], 1.55-3.22; P < .0001), need for new mechanical support (OR, 3.25; CI, 1.39-7.61; P = .007), prolonged ventilatory support (OR, 2.93; CI, 1.89-4.55; P < .0001), renal failure (OR, 5.42; CI, 1.94-15.15; P = .001), and mortality at 12 months (OR, 1.94; CI, 1.14-3.28; P = .01).

CONCLUSIONS

In the Randomized On Versus Off Bypass trial, the strategy of revascularization did not affect the rate of POAF. Age, race, and hypertension were predictors of POAF. POAF was independently associated with a higher short-term morbidity and higher 1-year mortality rates.

Outcomes after conversion in the Veterans Affairs randomized on versus off bypass trial

BACKGROUND

The Randomized On versus Off Bypass trial reported conversion of 12.4% (n = 137) off-pump coronary artery bypass (OPCAB) patients and 3.6% (n = 40) on-pump cardiopulmonary bypass (CPB) patients. This paper explored outcomes after conversions.

METHODS

Elective and urgent CABG patients (n = 2,203) at 18 sites were studied. Randomization within 54 participating surgeons occurred preoperatively, after which conversion occurred if clinically indicated. Conversion reasons and outcomes were captured prospectively with additional details retrospectively extracted from patient records by a core clinical group.

RESULTS

Conversion rates varied considerably across participating surgeons. Converted OPCAB patients had more right coronary disease and coronary targets less than 1.5 mm. Conversions were elective in 49.3% of cases, urgent in 27.2%, or emergent in 23.5%. Elective conversions were mainly for poor exposure-intramyocardial vessel (35.8%). Urgent and emergent conversions were usually for hemodynamic instability (89.2% and 75.0%, respectively). Compared with CPB and OPCAB patients, OPCAB-converted patients had more 30-day complications and deaths (composite outcome rate of 5.7% and 5.5% vs 17.5% respectively, p < 0.001). Thirty-day outcomes for OPCAB-converted patients trended worse for emergent versus elective conversions (31.3% vs 13.4%, respectively, p = 0.05). One-year composite outcome rate (death, nonfatal myocardial infarction or revascularization) in OPCAB-converted patients was worse than in CPB patients (13.5% vs 7.1%, p = 0.02), but similar to OPCAB-nonconverted (9.4%).

CONCLUSIONS

The OPCAB patients requiring conversion had worse 30-day and 1-year outcomes. The OPCAB patients with right coronary artery disease or small targets were more often converted. The 30-day composite outcome trended worst for emergent OPCAB conversions.

Impact of endoscopic versus open saphenous vein harvest technique on late coronary artery bypass grafting patient outcomes in the ROOBY (Randomized On/Off Bypass) Trial

OBJECTIVE

In the Randomized On/Off Bypass (ROOBY) Trial, the efficacy of on-pump versus off-pump coronary artery bypass grafting was evaluated. This ROOBY Trial planned subanalysis compared the effects on postbypass patient clinical outcomes and graft patency of endoscopic vein harvesting and open vein harvesting.

METHODS

From April 2003 to April 2007, the technique used for saphenous vein graft harvesting was recorded in 1471 cases. Of these, 894 patients (341 endoscopic harvest and 553 open harvest) also underwent coronary angiography 1 year after coronary artery bypass grafting. Univariate and multivariable analyses were used to compare patient outcomes in the endoscopic and open groups.

RESULTS

Preoperative patient characteristics were statistically similar between the endoscopic and open groups. Endoscopic vein harvest was used in 38% of the cases. There were no significant differences in both short-term and 1-year composite outcomes between the endoscopic and open groups. For patients with 1-year catheterization follow-up (n=894), the saphenous vein graft patency rate for the endoscopic group was lower than that in the open harvest group (74.5% vs 85.2%, P<.0001), and the repeat revascularization rate was significantly higher (6.7% vs 3.4%, P<.05). Multivariable regression documented no interaction effect between endoscopic approach and off-pump treatment.

CONCLUSIONS

In the ROOBY Trial, endoscopic vein harvest was associated with lower 1-year saphenous vein graft patency and higher 1-year revascularization rates, independent of the use of off-pump or on-pump cardiac surgical approach.

On-pump versus off-pump coronary-artery bypass surgery

BACKGROUND

Coronary-artery bypass grafting (CABG) has traditionally been performed with the use of cardiopulmonary bypass (on-pump CABG). CABG without cardiopulmonary bypass (off-pump CABG) might reduce the number of complications related to the heart-lung machine.

METHODS

We randomly assigned 2203 patients scheduled for urgent or elective CABG to either on-pump or off-pump procedures. The primary short-term end point was a composite of death or complications (reoperation, new mechanical support, cardiac arrest, coma, stroke, or renal failure) before discharge or within 30 days after surgery. The primary long-term end point was a composite of death from any cause, a repeat revascularization procedure, or a nonfatal myocardial infarction within 1 year after surgery. Secondary end points included the completeness of revascularization, graft patency at 1 year, neuropsychological outcomes, and the use of major resources.

RESULTS

There was no significant difference between off-pump and on-pump CABG in the rate of the 30-day composite outcome (7.0% and 5.6%, respectively; P=0.19). The rate of the 1-year composite outcome was higher for off-pump than for on-pump CABG (9.9% vs. 7.4%, P=0.04). The proportion of patients with fewer grafts completed than originally planned was higher with off-pump CABG than with on-pump CABG (17.8% vs. 11.1%, P<0.001). Follow-up angiograms in 1371 patients who underwent 4093 grafts revealed that the overall rate of graft patency was lower in the off-pump group than in the on-pump group (82.6% vs. 87.8%, P<0.01). There were no treatment-based differences in neuropsychological outcomes or short-term use of major resources.

CONCLUSIONS

At 1 year of follow-up, patients in the off-pump group had worse composite outcomes and poorer graft patency than did patients in the on-pump group. No significant differences between the techniques were found in neuropsychological outcomes or use of major resources. (ClinicalTrials.gov number, NCT00032630.).

Reoperation for bleeding in patients undergoing coronary artery bypass surgery: incidence, risk factors, time trends, and outcomes

BACKGROUND

Reoperation for bleeding represents an important complication in patients undergoing coronary artery bypass surgery (CABG). Yet, few studies have characterized risk factors and patient outcomes of this event.

METHODS AND RESULTS

We evaluated 528 686 CABG patients at >800 hospitals in the Society of Thoracic Surgeons National Cardiac Database (2004 to 2007). Clinical features and in-hospital outcomes were evaluated in patients with and without reoperation for bleeding after CABG. Logistic regression was used to identify predictors of risk of this event and to estimate weights for an additive risk score. A total of 12 652 CABG patients (2.4%) required reoperation for bleeding. These rates remained fairly stable over time (2.2%, 2.3%, 2.5%, and 2.4% from 2004 to 2007, respectively). Although overall operative mortality was 4.5-fold higher in patients requiring reoperation for bleeding versus those who did not (2.0% versus 9.1%), this mortality risk declined significantly over time (11.3%, 9.5%, 8.8%, and 8.2% from 2004 to 2007, respectively, P for trend=0.0006). Factors associated with higher risk for reoperation were identified by multivariable analysis (c statistic=0.60) and summarized into a simple bedside risk score. The risk-score performed well when tested in the validation set (Hosmer-Lemeshow P=0.16).

CONCLUSIONS

Reoperation for bleeding remains an important morbid event after CABG. Nonetheless, death in patients with this complication has decreased over time. Our risk tool should allow estimation of patients risk for reoperation for bleeding and promote preventive measures when feasible in this at-risk group.

ACCF/SCAI/STS/AATS/AHA/ASNC 2009 Appropriateness Criteria for Coronary Revascularization : a report of the American College of Cardiology Foundation Appropriateness Criteria Task Force, Society for Cardiovascular Angiography and Interventions, Society of Thoracic Surgeons, American Association for Thoracic Surgery, American Heart Association, and the American Society of Nuclear Cardiology. Endorsed by the American Society of Echocardiography, the Heart Failure Society of America, and the Society of Cardiovascular Computed Tomography

The American College of Cardiology Foundation (ACCF), Society for Cardiovascular Angiography and Interventions, Society of Thoracic Surgeons, and the American Association for Thoracic Surgery, along with key specialty and subspecialty societies, conducted an appropriateness review of common clinical scenarios in which coronary revascularization is frequently considered. The clinical scenarios were developed to mimic common situations encountered in everyday practice and included information on symptom status, extent of medical therapy, risk level as assessed by noninvasive testing, and coronary anatomy. Approximately 180 clinical scenarios were developed by a writing committee and scored by a separate technical panel on a scale of 1 to 9. Scores of 7 to 9 indicate that revascularization was considered appropriate and likely to improve health outcomes or survival. Scores of 1 to 3 indicate revascularization was considered inappropriate and unlikely to improve health outcomes or survival. The mid range (4 to 6) indicates a clinical scenario for which the likelihood that coronary revascularization would improve health outcomes or survival was considered uncertain. For the majority of the clinical scenarios, the panel only considered the appropriateness of revascularization irrespective of whether this was accomplished by percutaneous coronary intervention (PCI) or coronary artery bypass graft surgery (CABG). In a select subgroup of clinical scenarios in which revascularization is generally considered appropriate, the appropriateness of PCI and CABG individually as the primary mode of revascularization was considered. In general, the use of coronary revascularization for patients with acute coronary syndromes and combinations of significant symptoms and/or ischemia was viewed favorably. In contrast, revascularization of asymptomatic patients or patients with low-risk findings on noninvasive testing and minimal medical therapy were viewed less favorably. It is anticipated that these results will have an impact on physician decision making and patient education regarding expected benefits from revascularization and will help guide future research.

Improving quality of care in cardiac surgery: evaluating risk factors, processes of care, structures of care, and outcomes

The 1985 release of hospital report cards by the Health Care Financing Administration awakened the public's awareness of variations in outcomes following patient treatment. In 1972, the Department of Veterans Affairs initiated an oversight process for all VA-based cardiac surgery programs. In response to Public Law 99-166, the Continuous Improvement in Cardiac Surgery Program (CICSP) national database was developed in 1987. This CICSP effort reported variations in outcomes across VA cardiac programs. In 1997, the CICSP expanded (CICSP-X) to identify the interrelationships of risk factors with processes and structures of care, as well as clinical outcomes. Based on VA findings to date, these quality improvement endeavors appear to have positively affected short-term and longer-term cardiac surgical outcomes. To advance a new patient-focused paradigm for continuous improvement in cardiac surgical care quality for all US citizens, an integrated data-driven reporting approach with broad-based participation should be implemented to optimally improve patient care.

Native lung volume reduction surgery relieves functional graft compression after single-lung transplantation for chronic obstructive pulmonary disease

OBJECTIVE

Single-lung transplantation is an accepted treatment for end-stage lung disease caused by chronic obstructive pulmonary disease. A complication unique to single-lung transplantation for chronic obstructive pulmonary disease is graft dysfunction due to compression caused by native lung hyperinflation. We hypothesized that patients with functional compromise from native lung hyperinflation would benefit from native lung volume reduction surgery.

METHODS

The charts of all patients undergoing single-lung transplantation for chronic obstructive pulmonary disease were reviewed for lung volume reduction surgery of their native lung. Data regarding length of stay, surgical morbidity and mortality, overall survival, type of lung volume reduction surgery, and pulmonary function were recorded to evaluate the effect of lung volume reduction surgery.

RESULTS

Between February 1992 and May 2007, 206 single-lung transplantations were performed for chronic obstructive pulmonary disease. Ten (5%) patients had clinically significant graft compression from native lung hyperinflation. After excluding other causes for functional decline, these patients underwent a modified lung volume reduction surgery between 12 and 142 months after single-lung transplantation (mean, 50 months). Lung volume reduction surgery consisted of anatomic resection. Two (20%) of 10 patients died during their hospitalization. Of the remaining 8 patients, 7 (87.5%) have demonstrated functional improvement on the basis of forced expiratory volume in 1 second improving from 12% to 200% (mean improvement, 57%). Within 6 months of lung volume reduction surgery, mean 6-minute walk values improved significantly (866 to 1055 feet), whereas desaturation with exertion decreased significantly.

CONCLUSIONS

Lung volume reduction surgery by means of formal lobectomy in patients with native lung hyperinflation undergoing single-lung transplantation and significant graft compression appears feasible. Additionally, improvements in forced expiratory volume in 1 second can be accomplished in nearly all properly selected patients. Lung volume reduction surgery should be considered in patients with decreasing graft function caused by graft compression from native lung hyperinflation.