Zbynek Straka

Off-Pump or On-Pump Coronary-Artery Bypass Grafting at 30 Days

BACKGROUND The relative benefits and risks of performing coronary-artery bypass grafting (CABG) with a beating-heart technique (off-pump CABG), as compared with cardiopulmonary bypass (on-pump CABG), are not clearly established. METHODS At 79 centers in 19 countries, we randomly assigned 4752 patients in whom CABG was planned to undergo the procedure off-pump or on-pump. The first coprimary outcome was a composite of death, nonfatal stroke, nonfatal myocardial infarction, or new renal failure requiring dialysis at 30 days after randomization. RESULTS There was no significant difference in the rate of the primary composite outcome between off-pump and on-pump CABG (9.8% vs. 10.3%; hazard ratio for the off-pump group, 0.95; 95% confidence interval [CI], 0.79 to 1.14; P=0.59) or in any of its individual components. The use of off-pump CABG, as compared with on-pump CABG, significantly reduced the rates of blood-product transfusion (50.7% vs. 63.3%; relative risk, 0.80; 95% CI, 0.75 to 0.85; P<0.001), reoperation for perioperative bleeding (1.4% vs. 2.4%; relative risk, 0.61; 95% CI, 0.40 to 0.93; P=0.02), acute kidney injury (28.0% vs. 32.1%; relative risk, 0.87; 95% CI, 0.80 to 0.96; P=0.01), and respiratory complications (5.9% vs. 7.5%; relative risk, 0.79; 95% CI, 0.63 to 0.98; P=0.03) but increased the rate of early repeat revascularizations (0.7% vs. 0.2%; hazard ratio, 4.01; 95% CI, 1.34 to 12.0; P=0.01). CONCLUSIONS There was no significant difference between off-pump and on-pump CABG with respect to the 30-day rate of death, myocardial infarction, stroke, or renal failure requiring dialysis. The use of off-pump CABG resulted in reduced rates of transfusion, reoperation for perioperative bleeding, respiratory complications, and acute kidney injury but also resulted in an increased risk of early revascularization. (Funded by the Canadian Institutes of Health Research; CORONARY ClinicalTrials.gov number, NCT00463294.).

Effects of Off-Pump and On-Pump Coronary-Artery Bypass Grafting at 1 Year

BACKGROUND Previously, we reported that there was no significant difference at 30 days in the rate of a primary composite outcome of death, myocardial infarction, stroke, or new renal failure requiring dialysis between patients who underwent coronary-artery bypass grafting (CABG) performed with a beating-heart technique (off-pump) and those who underwent CABG performed with cardiopulmonary bypass (on-pump). We now report results on quality of life and cognitive function and on clinical outcomes at 1 year. METHODS We enrolled 4752 patients with coronary artery disease who were scheduled to undergo CABG and randomly assigned them to undergo the procedure off-pump or on-pump. Patients were enrolled at 79 centers in 19 countries. We assessed quality of life and cognitive function at discharge, at 30 days, and at 1 year and clinical outcomes at 1 year. RESULTS At 1 year, there was no significant difference in the rate of the primary composite outcome between off-pump and on-pump CABG (12.1% and 13.3%, respectively; hazard ratio with off-pump CABG, 0.91; 95% confidence interval [CI], 0.77 to 1.07; P=0.24). The rate of the primary outcome was also similar in the two groups in the period between 31 days and 1 year (hazard ratio, 0.79; 95% CI, 0.55 to 1.13; P=0.19). The rate of repeat coronary revascularization at 1 year was 1.4% in the off-pump group and 0.8% in the on-pump group (hazard ratio, 1.66; 95% CI, 0.95 to 2.89; P=0.07). There were no significant differences between the two groups at 1 year in measures of quality of life or neurocognitive function. CONCLUSIONS At 1 year after CABG, there was no significant difference between off-pump and on-pump CABG with respect to the primary composite outcome, the rate of repeat coronary revascularization, quality of life, or neurocognitive function. (Funded by the Canadian Institutes of Health Research; CORONARY ClinicalTrials.gov number, NCT00463294.).

One-Year Coronary Bypass Graft Patency A Randomized Comparison Between Off-Pump and On-Pump Surgery Angiographic Results of the PRAGUE-4 Trial

Background—Off-pump coronary bypass surgery has become a widely used technique during recent years. However, limited data are available with regard to 1-year patency of bypass grafts implanted on the beating heart in unselected consecutive bypass surgery candidates. The aim of this study was to compare 1-year angiographic patency of bypass grafts done on the beating heart (off pump) with those done classically (on pump). Methods and Results—The PRAGUE-4 trial randomized 400 consecutive nonselected cardiac surgery candidates into group A (on pump; n=192) and group B (off pump; n=208). One-year follow-up coronary angiography was done in 255 patients. The arterial graft patency after 1 year was 91% in both groups. Saphenous graft patency was 59% (on pump) versus 49% (off pump; P=NS). Saphenous graft patency per patient was lower in the off-pump group: 0.7 patent anastomosis per patient versus 1.1 patent anastomosis in the on-pump group (P<0.01). There were 46% on-pump patients with all grafts patent versus 52% off-pump patients (P=NS). Grafts anastomosed distally to collateralized chronic total occlusions of native coronary arteries remained patent in 100% on the left anterior descending artery compared with 23% on other arteries (P<0.0001). Conclusions—The patency of arterial coronary bypass grafts done on the beating heart is excellent and equal to grafts done on pump. The off-pump procedure in the unselected patient population results in fewer patent saphenous grafts per patient.

Routine immediate extubation for off-pump coronary artery bypass grafting without thoracic epidural analgesia

BACKGROUND The expansion of coronary surgery on the beating heart without cardiopulmonary bypass has led to increasing interest in ultra-fast track anesthesia, allowing extubation of the patient in the operating theater. The techniques described to date combined general anesthesia with thoracic epidural analgesia. We report the routine application of a technique that allows immediate extubation in the majority of patients undergoing off-pump coronary artery bypass grafting without thoracic epidural analgesia. METHODS Fast-track anesthesia using an ultra-shortacting opiate remifentanil, without epidural catheter insertion, was used in 160 unselected patients undergoing off-pump coronary artery bypass grafting (aged 43 to 83 years, mean 65 years). There were an average of 2.2 bypass procedures per patient, with the left internal mammary artery used in 93%. Contraindications to immediate extubation were (except for failure to meet standard extubation criteria) hemodynamic instability and persistent bleeding at the end of operation. Satisfactory postoperative pain control was achieved by continuous remifentanil (0.0125 to 0.05 microg x kg(-1) x min(-1)). RESULTS Operating theater extubation within 10 minutes of the end of operation was feasible in 150 patients (94%). Five patients (3%) were extubated within 2 hours, and the remaining 5 patients (3%) were converted to standard anesthesia. There were no deaths during hospitalization. Major complications included myocardial infarction and transient ischemic attacks (2 patients each). No pulmonary complications were seen. Episodes of atrial fibrillation occurred in 21% of the patients undergoing operation. CONCLUSIONS Immediate extubation is possible in most patients after off-pump coronary artery bypass grafting even without thoracic epidural analgesia. We believe this type of less invasive cardiac anesthesia is safe and promising.

Platelet activity and aspirin efficacy after off-pump compared with on-pump coronary artery bypass surgery: Results from the prospective randomized trial PRAGUE 11-Coronary Artery Bypass and REactivity of Thrombocytes (CABARET)

OBJECTIVES Changes in hemostasis after off-pump coronary artery bypass grafting are still being discussed. There is a lack of information about platelet activity and aspirin efficacy after coronary artery bypass grafting. The aim of this study was to assess and compare platelet activity and aspirin efficacy early and late after off-pump and on-pump coronary artery bypass grafting. METHODS Eighty patients were enrolled in a prospective randomized study. Platelet activity was determined based on membrane expression of antigen CD62P (P-selectin) by means of flow cytometric analysis. Aspirin efficacy was assessed by using arachidonic acid-induced platelet aggregation. Blood samples were collected before the operation, immediately postoperatively, and on days 1, 2, 5, and 30. RESULTS In the off-pump group expression of P-selectin was markedly increased in comparison with preoperative values, with a maximum difference observed on day 2 (+53%, P = .02), and it was significantly higher compared with that seen in the on-pump group on days 2 and 5 (+53% vs +4%, P = .004, and +20% vs -16%, P = .005). On day 30, P-selectin expression was similar both between the groups and in comparison with the preoperative values. Arachidonic acid-induced platelet aggregation was gradually decreasing until day 30, but on day 2, there was an unexpected increase in aggregation that was more expressed in the off-pump group. CONCLUSIONS The platelet activity is higher in the early postoperative period in off-pump compared with on-pump coronary artery bypass grafting. The present aspirin strategy seems to be insufficient in the early postoperative period, irrespective of the surgical technique used.

Rationale and design of The Coronary Artery Bypass Grafting Surgery Off or On Pump Revascularization Study: A large international randomized trial in cardiac surgery

BACKGROUND Uncertainty remains regarding the benefits and risks of the technique of operating on a beating heart (off pump) for coronary artery bypass grafting (CABG) surgery versus on-pump CABG. Prior trials had few events and relatively short follow-up. There is a need for a large randomized, controlled trial with long-term follow-up to inform both the short- and long-term impact of the 2 approaches to CABG. METHODS We plan to randomize 4,700 patients in whom CABG is planned to undergo the procedure on pump or off pump. The coprimary outcomes are a composite of total mortality, myocardial infarction (MI), stroke, and renal failure at 30 days and a composite of total mortality, MI, stroke, renal failure, and repeat revascularization at 5 years. We will also undertake a cost-effectiveness analysis at 30 days and 5 years after CABG surgery. Other outcomes include neurocognitive dysfunction, recurrence of angina, cardiovascular mortality, blood transfusions, and quality of life. RESULTS As of May 3, 2011, CORONARY has recruited >3,884 patients from 79 centers in 19 countries. Currently, patients mean age is 67.6 years, 80.7% are men, 47.0% have a history of diabetes, 51.4% have a history of smoking, and 34.4% had a previous MI. In addition, 20.9% of patients have a left main disease, and 96.6% have double or triple vessel disease. CONCLUSIONS CORONARY is the largest trial yet conducted comparing off-pump CABG to on-pump CABG. Its results will lead to a better understanding of the safety and efficacy of off-pump CABG.

Changes in cytokine concentrations following successful ablation of atrial fibrillation

AIMS Atrial fibrillation is associated with the activation of inflammatory processes [e.g. higher concentrations of pro-inflammatory cytokines interleukin-6 (IL-6), C-reactive protein (CRP)], as well as a pro-thrombotic state [e.g. increased concentration of serum pro-thrombotic markers P-selectin and CD40 ligand (CD40L)]. The aim of the present study was to establish, whether successful epicardial ablation of AF leads to decreased concentrations of traditional inflammatory and thrombotic markers. METHODS Twenty-five patients with symptomatic paroxysmal or persistent AF were prospectively studied. All underwent epicardial isolation of pulmonary veins. The success of the ablation was assessed clinically and with three Holter recordings. Blood samples were drawn before, three and six months after surgery. Serum concentrations of IL-6, interleukin-10 (IL-10), CRP, CD40L and P-selectin were measured using ELISA. RESULTS AF was successfully ablated in 15 patients (SR group). In the other 10 patients (AF group), AF re-occurred during follow-up. Neither group differed with respect to age, gender, left ventricular ejection fraction, or preoperative concentrations of measured molecules. The concentrations of IL-6, CRP and CD40L decreased in successfully ablated patients; however, there was no change in the concentrations of these molecules in the AF group. The concentrations of IL-10 and P-selectin were unchanged in both groups during follow-up. CONCLUSION Successful ablation of AF, with sinus rhythm restoration and maintenance, is associated with decreased serum levels of markers of inflammation.

Decreased Apoptosis following Successful Ablation of Atrial Fibrillation

Objectives: Increased apoptotic processes in tissue samples from hearts in atrial fibrillation (AF) have been previously documented in animals. Whether the restoration of sinus rhythm is associated with decreased apoptosis is not known. The aim of the present study was to establish whether successful epicardial ablation of AF leads to changes in the concentration of serum markers of apoptosis. Methods: Twenty-five patients with AF were prospectively studied. All underwent epicardial isolation of pulmonary veins. The success of the ablation was assessed clinically and with 3 Holter recordings. Blood samples were drawn before surgery, and at 3 and 6 months after. Serum concentrations of Fas (apoptosis-stimulating fragment) and TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) were measured using ELISA. Results: AF was successfully ablated in 15 patients (SR group). In the other 10 patients (AF group), AF recurred during follow-up. Neither group differed with respect to age, sex, left ventricular ejection fraction, or preoperative concentrations of measured molecules. While Fas decreased in successfully ablated patients, there was no change in the Fas concentration in the AF group. Similarly, the concentrations of TRAIL decreased in the SR group, but remained unchanged in the AF group. Conclusion: The ablation of AF is associated with decreased serum markers for apoptosis.

Electrophysiological findings after surgical thoracoscopic atrial fibrillation ablation

BACKGROUND Hybrid ablation (a combination of thoracoscopic epicardial ablation and catheter ablation) has become a new technique for atrial fibrillation treatment. OBJECTIVE The goal of this study was to evaluate the success and electrophysiological follow-up after using the COBRA Fusion device to deliver a circumferential lesion set anterior to the pulmonary veins in an attempt to isolate the posterior left atrium (box isolation). METHODS Surgical ablation was carried out via a thoracoscopic approach using the COBRA Fusion radiofrequency catheter. An electrophysiology study was done 2-3 months later to verify box isolation (and to complete it, if needed) and to perform right-sided isthmus ablation. Fat thickness along the presumed box lesion line was measured using preprocedural computed tomography. RESULTS Thirty patients (mean age 60.0 ± 11.6 years; 22 men; 8 with long-standing persistent AF and 22 with persistent atrial fibrillation) were enrolled. The duration of the EP study was 216.3 ± 64.2 minutes. Box isolation, based on the EP study, was complete in 12 patients (40%) and incomplete in 18 patients (60%). Successful box isolation was achieved with catheter ablation in 16 of 18 patients (89%). A total of 39 gaps in these 16 patients were identified. Typical gap locations were the anterior-superior part of the superior pulmonary veins and the roofline. Fat thickness along the roofline was substantially higher than that along the inferior line (4.58 ± 1.61 mm vs 2.37 ± 0.76 mm; P < .001). CONCLUSION There is a relatively low rate of complete isolation using the COBRA catheter ablation system. The superior line and anterior parts of superior pulmonary veins have most conduction gaps.

Predictors of complete arrhythmia free survival in patients undergoing surgical ablation for atrial fibrillation. PRAGUE-12 randomized study sub-analysis☆

BACKGROUND Surgical ablation (SA) is commonly used in atrial fibrillation (AF) patients undergoing cardiac surgery. However, its effect has been established in few randomized studies. To assess the complete atrial fibrillation free (AF-free) survival in randomized study assessing the effects of additional concomitant SA of AF in patients primarily indicated for other cardiac surgery. METHODS The PRAGUE-12 study was a prospective randomized study comparing the effect of adding SA to other cardiac surgery. We examined the data from the PRAGUE-12 trial and grouped patients according to complete AF-free survival. All patients had regular check-ups at 3, 6, 9 months, some of them with Holter recordings, and a final check-up at 12 months with Holter recording. RESULTS One hundred ninety-four patients were analyzed; 104 originally randomized to surgery with adding SA (SA group) and 90 without it (non-SA group). Complete AF-free status was found in 46 patients from the SA group (44.2%) and 25 patients (27.8%) from the non-SA group (p<0.05). In a multivariate logistic regression, the SA group was associated with a greater chance for complete AF-free survival (OR 1.87, p<0.05). In the multivariate analysis of the SA group, history of myocardial infarction (OR 0.2, p<0.05) and a higher EuroSCORE (OR 0.9, p 0.05) were independently associated with a lower probability of AF-free survival. CONCLUSION Complete AF-free survival following SA was present in almost one half of patients. Patients with a history of myocardial infarction and higher EuroSCOREs were less likely to benefit from an add-on SA procedure.