Postoperative atrial fibrillation is not pulmonary vein dependent: results from a randomized trial.

BACKGROUND: Although often short-lived and self-limiting, postoperative atrial fibrillation (POAF) is a well-recognized postoperative complication of cardiac surgery and is associated with a 2-fold increase in cardiovascular mortality and morbidity. OBJECTIVE: Our aim was to determine whether intraoperative bilateral pulmonary vein radiofrequency ablation decreases the incidence of POAF in patients undergoing coronary artery bypass grafting (CABG). METHODS: A total of 175 patients undergoing CABG was prospectively randomized to undergo adjuvant bilateral radiofrequency pulmonary vein ablation in addition to CABG (group A; n = 89) or CABG alone (group B; n = 86). Intraoperative pulmonary vein isolation was confirmed by the inability to pace the heart via the pulmonary veins after ablation. All patients received postoperative ß-blocker. RESULTS: There was no difference in the incidence of POAF in the treatment group who underwent adjuvant pulmonary vein ablation (group A; 37.1%) compared with the control group who did not (group B; 36.1%) (P = .887). There were no differences in postoperative inotropic support, antiarrhythmic drug use, need for oral anticoagulation, and complication rates. The mean length of postoperative hospital stay was 8.2 ± 6.5 days in the ablation group and 6.7 ± 4.6 days in the control group (P < .001). CONCLUSION: Adjuvant pulmonary vein isolation does not decrease the incidence of POAF or its clinical impact but increases the mean length of stay in the hospital. The mechanism of POAF does not appear to depend on the pulmonary veins.

Early and late outcomes after cardiac retransplantation.

BACKGROUND: Cardiac retransplantation remains the most viable option for patients with allograft heart failure; however, careful patient selection is paramount considering limited allograft resources. We analyzed clinical outcomes following retransplantation in an academic, tertiary care institution. METHODS: Between 1981 and 2011, 593 heart transplantations, including 22 retransplantations were performed at our institution. We analyzed the preoperative demographic characteristics, cause of allograft loss, short- and long-term surgical outcomes and cause of death among patients who had cardiac retransplantations. RESULTS: Twenty-two patients underwent retransplantation: 10 for graft vascular disease, 7 for acute rejection and 5 for primary graft failure. Mean age at retransplantation was 43 (standard deviation [SD] 15) years; 6 patients were women. Thirteen patients were critically ill preoperatively, requiring inotropes and/or mechanical support. The median interval between primary and retransplantation was 2.2 (range 0-16) years. Thirty-day mortality was 31.8%, and conditional (> 30 d) 1-, 5- and 10-year survival after retransplantation were 93%, 79% and 59%, respectively. A diagnosis of allograft vasculopathy (p = 0.008) and an interval between primary and retransplantation greater than 1 year (p = 0.016) had a significantly favourable impact on 30-day mortality. The median and mean survival after retransplantation were 3.3 and 5 (SD 6, range 0-18) years, respectively; graft vascular disease and multiorgan failure were the most common causes of death. CONCLUSION: Long-term outcomes for primary and retransplantation are similar if patients survive the 30-day postoperative period. Retransplantation within 1 year of the primary transplantation resulted in a high perioperative mortality and thus may be a contraindication to retransplantation.

Monitoring brain oxygen saturation during coronary bypass surgery improves outcomes in diabetic patients: a post hoc analysis.

BACKGROUND: Having previously demonstrated in a prospective study of 200 coronary artery bypass (CAB) patients that by using the brain as an index organ, interventions to improve cerebral oxygenation would have systemic outcome benefits, we undertook a post hoc analysis of the diabetic subset (n = 57) of the overall study group to determine whether the outcomes of these patients were similarly improved. METHODS: Case-report forms for the 200 CAB patients study patients with a preoperative diagnosis of diabetes mellitus were stratified to intraoperative cerebral regional oxygen saturation (rSO2) monitoring with active display and a treatment intervention protocol (intervention group, n = 28) or to blinded rSO2 monitoring (control group, n = 29) and analyzed. RESULTS: There were no significant differences between the 2 groups in overall risk factors, although there were trends toward a higher body mass index, a worse angina score, a worse grade of ventricle, and greater use of off-pump coronary revascularization in the control group of patients. The 2 groups were similar with respect to overall insulin dosage and perioperative blood glucose concentrations. Significantly more diabetic patients in the control group demonstrated profound cerebral desaturation, with an area under the curve of <50%/min (P = .043; d = 0.55), longer intensive care unit (ICU) stays (P = .045; d = 0.58), and longer overall postoperative hospital stays (P = .036; d = 0.47), compared with patients in the intervention group. Compared with the intervention group, the control group had a significantly higher incidence of sternal wound infection (P = .028; φ = 0.31) and a significantly greater number of diabetic patients with >2 postoperative complications (P = .006; φ = 0.37). An analysis after removing the patients who underwent off-pump surgery revealed that the control group had significantly more patients with sternal wound infections (5 versus 0; P = .047) and ≥2 postoperative complications (6 versus 0; P = .008) than the intervention group, as well as a trend toward longer ICU and postoperative hospitalization stays in the control group. CONCLUSION: Monitoring and management of cerebral rSO2 in diabetic CAB patients avoid profound cerebral desaturation and are associated with significantly lower incidences of complications and shorter postoperative lengths of stay. IMPLICATION STATEMENT: A post hoc analysis of the diabetic cohort of a prospective, randomized, and blinded study of CAB patients revealed that those in whom cerebral oxygen saturation was actively monitored and maintained demonstrated significantly lower incidences of complications, resulting in shorter ICU and postoperative hospital stays compared with an unmonitored control group.

Does the trainee's level of experience impact on patient safety and clinical outcomes in coronary artery bypass surgery?

BACKGROUND: There is a relative dearth of information on how the resident's level of training affects patient outcomes in cardiac surgery. We designed this study to determine if there were any significant differences in patient demographics and clinical outcomes of coronary artery bypass procedures (CABG) performed by residents of PGY 4/lower, residents of PGY 5/6, fellows, or consultants. METHODS: Standardized preoperative, intraoperative, and postoperative variables were prospectively collected and analyzed on 2906 isolated CABG procedures, performed between July 1999 and March 2006 with the primary surgeon prospectively classified as PGY4/lower, PGY5/6, fellow, and consultant. RESULTS: The number of cases performed by residents of PGY4/lower, PGY5/6, fellows and consultants were 179, 263, 301, and 2163, respectively. Preoperative demographics and comorbidities were similar except PGY4/lower group had more diabetics and consultant group had more patients requiring IABP. More non-LIMA arterial conduits were used in the consultant and fellow groups. However, there were neither significant differences in the mean number of grafts nor in the composite postoperative morbidity, median ICU, and hospital lengths of stay. Observed in-hospital mortality was 2.2%, 1.5%, 1.7%, and 2.7% (p = 0.49), respectively. CONCLUSIONS: Preoperative patient demographics and operative data were similar in all groups except that patients requiring IABP preoperatively were more likely operated on by consultants and arterial revascularization was performed more commonly by consultants and fellows. Postoperative mortality and morbidity rates were similar among all groups, thus demonstrating that with appropriate supervision, trainees of all levels can safely be taught CABG.

The new cardiac surgery patient: defying previous expectations.

BACKGROUND: Studies conducted before 1999 of patients who had coronary artery bypass graft surgery (CABG) have shown a tendency toward increasing preoperative risk factors. This study examines whether this trend of increasing risk in patients who have cardiac surgery has continued since 1999 and whether its effect on mortality and morbidity has changed. METHODS: We prospectively collected data for 2754 patients who had cardiac surgery, divided them into 4 cohorts based on the year of operation (2000-2003) and analyzed the data according to 56 predefined preoperative, operative and postoperative variables. RESULTS: There were no significant changes in most preoperative risk factors over time, except for significant decreases in the proportion of elective (p = 0.016) and emergency/salvage operations (p < 0.001) and increases in urgent procedures and in the number of patients with congestive heart failure (CHF) (p < 0.001). The proportion of CABG procedures decreased significantly, whereas the proportion of valve, CABG plus valve, and non-CABG surgeries increased. A significant increase in multiarterial graft use and a decrease in off-pump coronary artery bypass procedures were observed. Postoperative complication rates did not change during the 4 years except for a significant decrease in wound infections. No significant changes in overall mortality and mortality across types of procedure were observed. Median observed/expected ratios for expected length of stay in hospital and risk of mortality did not change significantly over time. CONCLUSION: Patients' risk factors, except for CHF, did not change from 2000 to 2003. Despite more complicated procedures, the postoperative complication rates did not change except for a decrease in wound infections. These results suggest that the assumption of an inexorably increasing patient risk profile should be re-evaluated.

Angiographic, pathologic, and clinical relationships in coronary artery disease in cardiac allografts.

BACKGROUND: To date, the etiologic factors involved in the development of allograft coronary disease remain speculative and the treatment uncertain. The purpose of this study was to review the relationship of clinical, angiographic, and pathologic features of cardiac allograft vascular disease in a large population of heart transplant recipients followed for up to 15 years. METHODS: From 1981 to 1996, 789 angiograms from 255 cardiac allografts were reviewed to determine the prevalence and severity of coronary artery disease. Demographic, clinical, and laboratory variables were analyzed to identify factors associated with the presence of angiographic coronary artery disease. In addition, pathologic examination was performed on many of the lost grafts. RESULTS: Unsuspected severe donor coronary artery disease may be responsible for up to 10% of early graft failures. Angiographic coronary artery disease prevalence increased by approximately 10% with every 2-year interval after transplantation. Angiographic coronary artery disease consisted most often of minor luminal irregularities. Severe disease occurred in 12% of patients. At 1 year, the most significant factors associated with the presence of coronary artery disease were older donor age and the number of rejection episodes. Immunologic factors as well as traditional coronary risk factors such as hypercholesterolemia and hyperglycemia may play an important role in the genesis and progression of later-developing abnormalities. CONCLUSIONS: Cardiac allograft coronary artery disease is a major limiting factor to the long-term success of cardiac transplantation. Immune processes, as well as traditional coronary artery disease risk factors, appear to play a role in the development of this disease.

Is obesity a predictor of mortality, morbidity and readmission after cardiac surgery?

INTRODUCTION: Obesity has been described as a risk factor for the development of coronary artery disease, but it has not been determined whether obesity is associated with adverse outcomes after cardiac surgery. Therefore, we analyzed a large cohort of patients who had undergone cardiac surgery to determine whether obesity is a predictor of mortality, morbidity or early readmission to hospital. METHODS: At the London Health Sciences Centre, an academic tertiary care centre, we prospectively entered data from the cardiac surgical database from July 1999 to April 2002. We collected data on 1310 consecutive, unselected patients who underwent cardiac surgery during that time. We assessed the degree of obesity using the body mass index (BMI), and we prospectively documented the occurrence of 10 major complications after surgery. They included stroke, reoperation for bleeding, life-threatening cardiac arrest or arrhythmia, new renal failure requiring dialysis, septicemia, mediastinitis, sternal dehiscence, respiratory failure, postoperative myocardial infarction and low cardiac output necessitating intra-aortic balloon pump use. Univariable and multivariable analyses were conducted to determine the factors associated with and predictive of postoperative death and major complications. RESULTS: An increased BMI did not increase the risk of early postoperative death. Furthermore, increased BMI was not a predictor of a patient experiencing any of the major complications, except sternal dehiscence. An increased BMI was associated with a higher likelihood of readmission to hospital within 30 days of discharge. CONCLUSION: Obesity was not associated with adverse outcomes after cardiac operations, aside from the increased risks of sternal dehiscence and early hospital readmission.

Effect of off-pump coronary artery bypass grafting on risk-adjusted and cumulative sum failure outcomes after coronary artery surgery.

BACKGROUND AND AIM: We have shown that cumulative sum (CUSUM) failure analysis may be more sensitive than standard statistical methods in detecting a cluster of adverse patient outcomes after cardiac surgical procedures. We therefore applied CUSUM, as well as standard statistical techniques, to analyze a surgeon's experience with off-pump coronary artery bypass grafting (OPCAB) and on-pump procedures to determine whether the two techniques have similar or different outcomes. METHODS: In 320 patients undergoing nonemergent, first time coronary artery bypass grafting, preoperative patient characteristics, rates of mortality and major complications, and ICU and hospital lengths of stay were compared between the on-pump and OPCAB cohorts using Fisher's exact tests and Wilcoxon two sample tests. Predicted mortality and length of stay were determined using previously validated models of the Cardiac Care Network of Ontario. Observed versus expected ratios of both variables were calculated for the two types of procedures. Furthermore, CUSUM curves were constructed for the on-pump and OPCAB cohorts. A multivariable analysis of the predictors of hospital length of stay was also performed to determine whether the type of coronary artery bypass procedure had an independent impact on this variable. RESULTS: The predicted mortality risk and predicted hospital length of stay were almost identical in the 208 on-pump patients (2.2 +/- 3.9%; 8.2 +/- 2.5 days) and the 112 OPCAB patients (2.0 +/- 2.2%; 7.8 +/- 2.1 days). The incidence of hospital mortality and postoperative stroke were 2.9% and 2.4% in on-pump patients versus zero in OPCAB patients (p = 0.09 and 0.17, respectively). Mechanical ventilation for greater than 48 hours was significantly less common in OPCAB (1.8%) than in on-pump patients (7.7%, p = 0.04). The rate of 10 major complications was 14.9% in on-pump versus 8.0% in OPCAB patients (p = 0.08). OPCAB patients experienced a hospital length of stay that was a median of 1.0 day shorter than on-pump patients (p = 0.01). The observed versus expected ratio for length of stay was 0.78 in OPCAB patients versus 0.95 in on-pump patients. On CUSUM analysis, the failure curve in OPCAB patients was negative and was flatter than that of on-pump patients throughout the duration of the study. Furthermore, OPCAB was an independent predictor of a reduced hospital length of stay on multivariable analysis. CONCLUSIONS: OPCAB was associated with better outcomes than on-pump coronary artery bypass despite a similar predicted risk. This robust finding was documented on sensitive CUSUM analysis, using standard statistical techniques and on a multivariable analysis of the independent predictors of hospital length of stay.