Does preoperative atrial fibrillation reduce survival after coronary artery bypass grafting?

BACKGROUND: Preoperative atrial fibrillation has been identified as a risk factor for reduced long-term survival after coronary artery bypass grafting. This study sought to determine whether atrial fibrillation is merely a marker for high-risk patients or an independent risk factor for time-related mortality. METHODS: From 1972 to 2000, 46,984 patients underwent primary isolated coronary artery bypass grafting; 451 (0.96% prevalence) had electrocardiogram-documented preoperative atrial fibrillation (n = 411) or flutter (n = 40). Characteristics of patients with and without atrial fibrillation were contrasted by multivariable logistic regression to form a propensity score. With this, comparable groups with and without atrial fibrillation were formed by pairwise propensity-matching to assess survival. RESULTS: Patients with preoperative atrial fibrillation were older (67 +/- 9.0 versus 59 +/- 9.8 years, p < 0.0001), had more left ventricular dysfunction (66% versus 52%, p < 0.0001) and hypertension (73% versus 59%, p < 0.0001), but less severe angina (39% moderate or severe versus 49%, p < 0.0001). Many of these factors are themselves predictors of increased time-related mortality. In propensity-matched patients, survival at 30 days and at 5 and 10 years for patients with versus without atrial fibrillation was 97% versus 99%, 68% versus 85%, and 42% versus 66%, respectively, a survival difference at 10 years of 24%. Median survival in patients with atrial fibrillation was 8.7 years versus 14 years for those without it. CONCLUSIONS: Atrial fibrillation in patients undergoing coronary artery bypass grafting is a marker for high-risk patients; in addition, atrial fibrillation itself substantially reduces long-term survival. Thus, if patients in atrial fibrillation require surgical revascularization, it is appropriate to consider performing a concomitant surgical ablation procedure.     

Is there a role for endothelin-blockade early after coronary artery bypass grafting?

BACKGROUND: Diverse results exist regarding myocardial release of endothelin after coronary artery bypass grafting. Because endothelin may be involved in regulation of coronary blood flow, postoperative endothelin-blockade could influence the surgical outcome. In this study, we have evaluated the cardiac outflow of endothelin and effects on coronary flow by endothelin-blockade immediately after completion of the coronary bypass grafting. METHODS: Thirty patients were subjected to infusions of endothelinA blocker (BQ-123, 260 nmoL/min for up to 30 minutes) or endothelinA blocker and endothelinB blocker (BQ-123 and BQ-788, 260 and 250 nmol/min, respectively, for up to 30 minutes) into a veingraft anastomosed to a coronary vessel, and the coronary blood flow was measured. Plasma levels of endothelin from the coronary sinus and the periphery were determined. RESULTS: There were no significant changes in flow caused by endothelinA blockade alone or in combination with endothelinB blockade. There were no immediately increased levels of endothelin after surgery or after infusions of the endothelin blockers. CONCLUSIONS: Endothelin blockade does not influence the immediate perioperative myocardial blood flow after coronary bypass grafting. There is no significantly increased myocardial outflow of endothelin, and endothelin does not have any influence on the basal tone of the coronary vessels in the early phase after coronary bypass grafting.     

Is coronary artery bypass grafting without cardiopulmonary bypass safe?

Summary Three hundred and fifty patients underwent coronary artery bypass surgery on a beating heart. This technique is easy to learn and is suitable in selected patients.     

Pulmonary artery catheter placement for elective coronary artery bypass grafting: before or after anesthetic induction?

Pulmonary arterial catheters (PACs) are often used during and after coronary artery bypass grafting. We hypothesized that placement of a PAC would be faster in anesthetized patients. We further hypothesized that the presence or absence of a PAC during the induction of anesthesia would make no difference in hemodynamics, vasoactive drug use, or IV fluid administration during the induction. Patients (n = 200) undergoing elective coronary artery bypass grafting were assigned to PAC insertion either before or after the induction of anesthesia. Total time for PAC insertion, number of finder needle and venous catheter insertion attempts, incidence of carotid artery puncture, arrhythmias or ST segment changes, arterial blood gas analysis, hemodynamic variables, IV fluids, and vasoactive drugs required during and after the anesthetic induction were recorded. Thirty-two different physicians placed the PACs. PAC placement was faster (10 versus 12 min, P = 0.0003) and required fewer punctures with a finder needle (P = 0.0107) in anesthetized patients. There were no significant differences between groups in hemodynamic values or use of vasoactive or anesthetic drugs or IV fluids during the induction. There were also no significant differences between groups in the incidence of myocardial ischemia, arterial hypoxemia, or hypercarbia. Placement of a PAC before the induction of anesthesia consumes more time and fails to improve hemodynamic stability or lessen vasoactive drug use during the induction of anesthesia. IMPLICATIONS: Insertion of pulmonary artery catheters (PACs) before the induction of anesthesia requires more needle sticks and takes longer than insertion after the induction of anesthesia; moreover, previous PAC insertion has no significant effect on hemodynamics or use of vasoactive drugs or IV fluid associated with the induction of anesthesia.     

Do we still need CK-MB in coronary artery bypass grafting surgery?

AIM: The aim of this study was to evaluate the role of cardiac Troponin I (cTnI) and CK-MB for early prediction of outcome of patients undergoing coronary artery bypass grafting (CABG) surgery. METHODS: In 134 consecutive patients undergoing CABG-surgery blood samples were analyzed for cTnI concentration and CK-MB activity. ECG, hemodynamic parameters and the need for inotropic support, were continuously registered. Patients were divided into group A (uneventful course), group B (ischemia by ECG, hemodynamic stability) and group C (ischemia by ECG and IABP). RESULTS: After removal of X-clamp an increase cTnI and CK-MB was observed in all patients. Five hrs after stop of CPB group A (8.3+/-4.2 microg/L) had lower cTnI values compared to group B (14.8+/-5.3 microg/L) (p=0.035) and C (54+/-22.8 microg/L) (p=0.023). The cut off value was 14.8 microg/L. Sensitivity and specificity (99%/97%) was higher for cTnI than for CK-MB (90%/30%). The positive predictive value of outcome was better for cTnI (86%) than for CK-MB (33%). CONCLUSION: CTnI is a specific and sensitive marker for evaluation of perioperative myocardial ischemia (PMI). Additional determination of CK-MB activity does not provide further clinical information. CTnI should be the marker of first choice in CABG surgery.     

Which place for Port Access surgery in coronary artery bypass grafting? A mid-term follow up study

Between May 1997 and November 2002, 68 patients with one or two-vessel disease (55+/-9 years) underwent Port Access CABG using the Heartport endoCPB. The LITA was used in 63 cases, the RITA in 14, a radial artery in 2 and a vein graft in 3. Mean distal anastomoses was 1.3+/-0.5. Cross clamping, CPB, and operative times were 42+/-20 min, 64+/-27 min, and 3.8+/-1.5 h. Postoperative ventilation was 11+/-17 h, and ICU stay was 1.9+/-2.6 days. At day-1, troponin level was 2.3+/-2.9 UI and blood loss was 398+/-240 ml. Two patients needed long intubation and two had pleural re-drainage. One patient had a stroke, one had a myocardial infarction, and one underwent revision for bleeding. Hospital stay was 7+/-3 days. 65% were discharged to home. Follow up was completed in all cases (4.1+/-1.8 years). CCS score was significantly reduced (from 3.1+/-0.3 to 1.1+/-0.3, P<0.0001). Two patients had PTCA and stenting of non-grafted arteries. Five other patients had recurrent angina. Angiograms showed patent grafts in all cases. Two patients died after 19 months and 5 years from non cardiac reasons. In conclusion, Port Access CABG remains a safe technique with stable results at mid-term follow up.     

Do off-pump techniques reduce the incidence of postoperative atrial fibrillation in elderly patients undergoing coronary artery bypass grafting?

BACKGROUND: Atrial fibrillation is the most common postoperative complication in patients undergoing coronary artery bypass grafting (CABG) with advancing age having been shown to have a significant association with its incidence. This study aims to assess whether off-pump coronary artery bypass (OPCAB) reduces the incidence of atrial fibrillation in elderly patients. METHODS: A meta-analysis of all observational studies reporting a comparison between the two techniques in elderly patients (> 70 years) between 1999-2003 was performed. The primary outcome of interest was the incidence of postoperative atrial fibrillation. The quality of each study was evaluated by examining three items: patient selection, matching of the off-pump and cardiopulmonary bypass patient groups, and assessment of outcome. Meta-regression analysis was undertaken to see the effects of study size and quality on the calculated odds ratio. RESULTS: Eight studies fulfilled our inclusion criteria, all of which were nonrandomized. In total the studies identified 3017 subjects, of which 764 had off-pump surgery (25%) and 2253 underwent cardiopulmonary bypass (75%). Meta-analysis showed that after off-pump surgery there was a significantly lower incidence of postoperative atrial fibrillation in these patients (odds ratio 0.70, 95% confidence interval [CI] 0.56-0.89). Meta-regression analysis including study characteristics did not show any associations affecting the calculated odds ratio of atrial fibrillation. CONCLUSIONS: Our study demonstrates a reduced incidence of postoperative atrial fibrillation in an elderly population with off-pump as compared with cardiopulmonary bypass techniques. We appreciate, however, that our statistical analysis uses nonrandomized published data and that the results must be treated with caution. If this finding is confirmed by a large-scale randomized trial, it has significant implications on the operative strategy employed for this patient group.