Mitchell J. Magee

Elimination of cardiopulmonary bypass improves early survival for multivessel coronary artery bypass patients.

BACKGROUND Coronary artery bypass graft (CABG) surgery performed without cardiopulmonary bypass (CPB) is currently increasing in clinical practice. Decreased morbidity associated with off-pump (OP) CABG in selected risk groups examined in relatively small, single institution groups has been the focus of most recent studies. The purpose of this study was to determine the independent impact of CPB on early survival in all isolated multivessel CABG patients undergoing surgery in two large institutions with established experience in OPCABG techniques. METHODS A review of two large databases employed by multiple surgeons in the hospitals of two institutions identified 8,758 multivessel CABG procedures performed from January 1998 through July 2000. In all, 8,449 procedures were included in a multivariate logistic regression analysis to determine the relative impact of CPB on mortality independent of known risk factors for mortality. Procedures were also divided into two treatment groups based on the use of CPB: 6,466 had CABG with CPB (CABG-CPB), 1,983 had CABG without CPB (OPCABG). Disparities between groups were identified by univariate analysis of 17 preoperative risk factors and treatment groups were compared by Parsonnets risk stratification model. Finally, computer-matched groups based on propensity score for institution selection for OPCABG were combined and analyzed by a logistic regression model predicting risk for mortality. RESULTS CABG-CPB was associated with increased mortality compared with OPCABG by univariate analysis, 3.5% versus 1.8%, despite a lower predicted risk in the CABG-CPB group. CPB was associated with increased mortality by multiple logistic regression analysis with an odds ratio of 1.79 (95% confidence interval = 1.24 to 2.67). An increased risk of mortality associated with CPB was also determined by logistic regression analysis of the combined computer-matched groups based on OPCABG-selection propensity scores with an odds ratio of 1.9 (95% confidence interval = 1.2 to 3.1). CONCLUSIONS Elimination of CPB improves early survival in multivessel CABG patients. Rigorous attempts to statistically account for selection bias maintained a clear association between CPB and increased mortality. Larger multiinstitutional studies are needed to confirm these findings and determine the most appropriate application of OPCABG.

Conversion in Off-Pump coronary artery bypass grafting: an analysis of predictors and outcomes

BACKGROUND The incidence, predictive factors, and outcomes related to conversion from off-pump coronary artery bypass (OPCAB) to on-pump coronary artery bypass grafting (ONCAB) have not been well defined. We sought to determine the incidence of conversion, predictive factors, and any associated adverse consequences. METHODS From January 2000 through June 2002, 1,644 patients underwent nonemergent OPCAB with 61 patients requiring conversion from OPCAB to ONCAB. These groups were retrospectively compared by univariate and multivariate regression analysis. The converted group was then computer matched 1:3, to a cohort of ONCAB patients to determine differences in outcomes. RESULTS The overall conversion rate was 3.71%. Converted patients compared with a computer-matched ONCAB patients had a higher incidence of operative mortality (18.0% versus 2.7%, p < 0.001). Urgently converted patients had a higher incidence of postoperative cardiac arrest (25% versus 1.1%, p < 0.001), multisystem organ failure (10.7% versus 0.6%, p < 0.001), vascular complications (7.1% versus 1.1%, p = 0.03), and perioperative myocardial infarction (10.7% versus 1.1%, p = 0.02). Predictive factors for conversion were surgeon early in OPCAB experience (odds ratio [OR] 4.4), previous CABG (OR 2.8), and congestive heart failure (OR 2.0). The need for urgent-emergent conversion was highly predictive for operative mortality (OR 7.3) compared with elective conversion. CONCLUSIONS Patients undergoing urgent-emergent but not elective conversion from OPCAB to ONCAB had a significantly higher risk of mortality and morbidity compared with patients whose procedure was initially ONCAB. Variables predictive of conversion included previous CABG, congestive heart failure, and surgeons early in OPCAB experience.

Effect of Bovine Pericardial Strips on Air Leak After Stapled Pulmonary Resection

BACKGROUND Surgical procedures for emphysema have been proposed and in many settings resulted in significant improvement in dyspnea and function. The most prevalent surgical problem in all series is prolonged postoperative air leak. METHODS One hundred twenty-three patients undergoing stapled thoracoscopic unilateral lung volume reduction operation were prospectively randomized to receive either no buttressing of their staple lines or buttressing of all staple lines with bovine pericardial strips. RESULTS The two groups were comparable in preoperative risks and in the severity of their emphysema. Postoperative complications were identical in the two groups with respect to pneumonia, empyema, and wound infection; however, there was a significant difference in the duration of postoperative air leaks. Those having the pericardial strips used to buttress their staple lines had chest tubes removed 2.5 days sooner and were discharged from the hospital 2.8 days sooner as a result. The cost data revealed that because of the cost of the pericardial sleeves, the overall hospital charges were almost identical for the two groups (

Influence of diabetes on mortality and morbidity: off-pump coronary artery bypass grafting versus coronary artery bypass grafting with cardiopulmonary bypass

22,108 bovine,

Patient Selection and Current Practice Strategy for Off-pump Coronary Artery Bypass Surgery

22,060 no bovine) in spite of the shortened hospital stay. CONCLUSIONS The use of bovine pericardial sleeves to buttress the staple lines in thoracoscopic unilateral lung volume reduction operation results in a shorter duration of postoperative air leaks. Total hospital charges were comparable in the two groups as the 2.8 days saved in the hospital were offset by the cost of the pericardial sleeves.

Coronary Artery Bypass Graft Failure After On-Pump and Off-Pump Coronary Artery Bypass: Findings From PREVENT IV

BACKGROUND Myocardial revascularization in diabetic patients is challenging with no established optimum treatment strategy. We reviewed our coronary artery bypass grafting experience to determine the impact of eliminating cardiopulmonary bypass on outcomes in diabetic patients relative to nondiabetic patients. METHODS From January 1995 through December 1999, 9,965 patients, of whom 2,891 (29%) had diabetes, underwent isolated coronary artery bypass grafting. Diabetic and nondiabetic patients were further divided into groups on the basis of cardiopulmonary bypass use. Twelve percent (346 of 2,891) of diabetic patients and 12% (829 of 7,074) of nondiabetic patients underwent coronary artery bypass grafting without cardiopulmonary bypass; the remainder had coronary artery bypass grafting with cardiopulmonary bypass. Nineteen preoperative variables were compared among treatment groups by univariate analysis. RESULTS Patients undergoing coronary artery bypass grafting without cardiopulmonary bypass compared with those having coronary artery bypass grafting with cardiopulmonary bypass had higher mean predicted mortalities (diabetic, 3.96% versus 3.72%, p = 0.83; nondiabetic, 3.03% versus 2.86%, p = 0.79). In nondiabetic patients, coronary artery bypass grafting without cardiopulmonary bypass provides an actual and risk-adjusted survival advantage over coronary artery bypass grafting with cardiopulmonary bypass (1.81% versus 3.44%, p = 0.0127; risk-adjusted mortality, 1.79% versus 3.61%, p = 0.007). This survival benefit of coronary artery bypass grafting without cardiopulmonary bypass was not seen in diabetic patients (2.89% versus 3.69%, p = 0.452; risk-adjusted mortality, 2.19% versus 2.98%, p = 0.42). Diabetic patients undergoing coronary artery bypass grafting without cardiopulmonary bypass had fewer complications, including decreased blood product use (34.39% versus 58.4%, p = 0.001), and reduced incidence of prolonged ventilation (6.94% versus 12.10%, p = 0.005), atrial fibrillation (15.90% versus 23.26%, p = 0.002), and renal failure requiring dialysis (0.87% versus 2.75%, p = 0.036). CONCLUSIONS The survival advantage in nondiabetic patients treated with coronary artery bypass grafting without cardiopulmonary bypass is not apparent in diabetic patients. Coronary artery bypass grafting without cardiopulmonary bypass in diabetic patients is nevertheless associated with a significant reduction in morbidity.

Off-pump bypass grafting is safe in patients with left main coronary disease.

Objective—Previous studies comparing off-pump coronary artery bypass surgery (OPCABG) to conventional techniques utilizing cardiopulmonary bypass (CABG-CPB) have failed to provide patient selection guidelines. We sought to determine guidelines, attempting to rectify the limitations of previous studies. Methods and Results—A retrospective analysis of prospectively collected data from the Society of Thoracic Surgeons National Database, from January 1999 through December 2000, identified 204 602 multivessel coronary artery bypass (CABG) patients. Unadjusted and risk-adjusted odds ratios (OR) were calculated to compare OPCABG and CABG-CPB morbidity and mortality. A propensity model was developed to identify factors associated with selection for OPCABG. All off-pump patients were pair-matched with on-pump patients based on their propensity to receive an off-pump procedure. Off-pump patients, 8.8% of the total, had significantly different patient characteristics than the on-pump group. Characteristics associated with OPCABG selection included fewer diseased vessels, absence of left main disease, fewer bypass grafts, no previous CABG, older age, chronic lung disease, and renal failure. Unadjusted and risk-adjusted odds ratios indicate a significant off-pump survival benefit and decreased morbidity including stroke and renal failure in the overall group. Propensity matching also showed a significant OPCABG survival benefit [OR (95% CI) 0.83 (0.72, 0.96)]. Subgroup analysis of propensity-matched groups identified off-pump survival benefits in patients with previous CABG (OR=0.53), diabetics (OR=0.66), LVEF between 30% to 50% (OR=0.75), females (OR=0.79), and age 66 to 75 years (OR=0.80). Conclusion—OPCABG imparts some survival benefit to most patient subgroups. Higher risk patients including those undergoing reoperative CABG, diabetics, and the elderly may gain the most benefit.

Thoracoscopic laser bullectomy: A prospective study with three-month results

BACKGROUND This analysis compares 1-year vein graft patency and major adverse cardiac and cerebral events (MACCE [death, myocardial infarction, or stroke]) in on-pump and off-pump patients enrolled in PREVENT IV (the PRoject of Ex-vivo Vein graft ENgineering via Transfection IV). METHODS The PREVENT IV was a multicenter (107 sites) randomized trial of edifoligide to prevent vein graft failure from neointimal hyperplasia in 3,014 patients undergoing primary, isolated coronary artery bypass grafting (CABG) with at least two vein grafts. One-year angiographic follow-up was completed on 1,920 patients (4,736 grafts) with MACCE follow-up on 99.4% of enrolled patients. RESULTS In all, 2,377 procedures (78.9%) were on pump and 637 (21.1%) were off pump. On-pump patients had more chronic lung disease (17% versus 11%; p < 0.001), congestive heart failure (10% versus 7%; p = 0.03), lower mean ejection fraction (50% versus 55%; p < 0.001), and worse target artery quality (good 63.8% versus 68.1%; fair 26.4% versus 22.7%; poor 9.8% versus 9.2%; p < 0.001). Vein graft failure (more than 75% graft stenosis) in on- versus off-pump patients was 25.3% versus 25.7% (p = 0.62). After adjusting for differences in significant predictors of vein graft failure (target artery quality, surgery time, endoscopic vein harvest, more than 1 distal anastomosis/graft, and patient weight), the odds of vein graft failure was 0.82 (95% confidence interval: 0.67 to 1.00; p = 0.05) for on-pump versus off-pump patients. One-year mortality for on- versus off-pump patients was 3.3% versus 2.5% (p = 0.30); and MACCE was 15.4% versus 11.3% (p = 0.01). The adjusted hazard ratio for 1-year MACCE was 1.31 (95% confidence interval: 1.01-1.69; p = 0.01) for on pump versus off pump. CONCLUSIONS Observed saphenous vein failure rate was 25% in both groups. One-year clinical outcomes (MACCE) were better with off-pump than with on-pump CABG, suggesting benefits not related to vein graft patency.

Long-term survival after thoracoscopic lung volume reduction: a multiinstitutional review.

BACKGROUND Because of a concern about the ability to tolerate beating heart grafting, patients with left main coronary artery stenosis have been excluded from off-pump bypass. We reviewed our experience with off-pump coronary artery bypass grafting for patients with left main coronary artery disease. METHODS Eight hundred twenty-three patients underwent bypass grafting for left main coronary artery disease from January 1998 to October 1999. One hundred patients were revascularized without the use of cardiopulmonary bypass and compared with a contemporaneous cohort of 723 patients who underwent grafting with the aid of cardiopulmonary bypass. All patients had multivessel grafting performed through a sternotomy. RESULTS There was one death (1%) in the group undergoing off-pump grafting as compared with a 30-day mortality of 4.7% (p = 0.059) in the on-pump group. Univariate analysis established that patients revascularized without cardiopulmonary bypass were significantly less likely to require postoperative inotropic support (23% versus 62%, p < 0.001) and transfusion (35% versus 67%, p < 0.001). Logistic regression analysis revealed that cardiopulmonary bypass was an independent risk factor for mortality (odds ratio, 7.3; 95% confidence interval, 1.34 to 138.4). CONCLUSIONS Coronary artery bypass grafting using off-pump techniques are safe and effective in left main coronary artery disease.

Predictors of Major Morbidity or Mortality After Resection for Esophageal Cancer: A Society of Thoracic Surgeons General Thoracic Surgery Database Risk Adjustment Model

One hundred forty-one patients were prospectively enrolled in a study of contact-tip laser bullectomy at four institutions. Ninety-one have had both preoperative and postoperative testing at 3 months. Nonsmoking patients with disabling dyspnea at less than 50 yards and with a forced expiratory volume in 1 second of 35% or less were enrolled. Testing included formal pulmonary function tests, arterial blood gasses, computed tomographic scans, ventilation/perfusion scans, echocardiograms, electrocardiograms, 6-minute walk testing, transdiaphragmatic pressures, and quality of life and dyspnea index questionnaires. A modest 16% improvement was noted in forced expiratory volume in 1 second (0.69 to 0.80 L), and there was a 29% improvement in 6-minute walk distances (655.2 to 846.3 feet). Oxygen use was completely discontinued in 16%. Risk factors for mortality included age, 6-minute walk distances, low diffusing capacity for carbon monoxide, high carbon dioxide tension, and high base excess. Minor improvement was judged from the dyspnea index and the Medical Outcome Study Short Form-36. Preoperative predictors of good outcome included heterogeneous disease, lack of carbon dioxide retention, and no emaciation (weight < 40 kg). Comparison of our results with those in the literature suggests that the improvement seen with the contact neodymium:yttrium-aluminum-garnet laser is not as good as that provided by the stapled techniques for volume reduction.