Predictors of atrial fibrillation after coronary artery bypass surgery

OBJECTIVE: Atrial fibrillation is one of the most common arrhythmias associated with not only increased morbidity after coronary artery bypass grafting but also increased healthcare costs. Many factors are associated with atrial fibrillation onset after coronary artery bypass grafting. We prospectively examined which factors could predict atrial fibrillation after coronary artery bypass grafting. METHODS: Fifty-seven consecutive patients (37 men, mean age=60.2+/-12 years) with sinus rhythm before coronary artery bypass grafting are included the study. Clinical, demographic, laboratory and echocardiographic characteristics are all evaluated prospectively. The maximum and minimum P-wave duration (P(max) and P(min)) were measured from the 12-lead surface electrocardiogram. The difference between the P(max) and the P(min) was calculated and defined as P-wave dispersion. Preoperative venous blood samples were taken for N-terminal proBrain natriuretic peptide level analysis. RESULTS: Ten (17%) patients had postoperative atrial fibrillation. Patients with postoperative atrial fibrillation were older (69.4+/-6 versus 58.2+/-12 years, P=0.01), had lower ejection fraction (44.1+/-8.9% versus 54.3+/-9; P=0.002), higher proBrain natriuretic peptide levels (538+/-136 pg/ml versus 293+/-359 pg/ml; P=0.03), longer P(max) (142.2+/-13.7 ms versus 120.8+/-21.2 ms; P=0.006) and longer P-wave dispersion (55.0+/-8.2 ms versus 41.3+/-14.3 ms; P=0.008) compared with the patients without atrial fibrillation. Univariate analysis showed that increased age (P=0.01), lower ejection fraction (P=0.02), enlargement of left atrium (P=0.02), increased P(max) (P=0.006) and increased P-wave dispersion (P=0.008) and increased level of preoperative proBrain natriuretic peptide (P=0.03) were associated with postoperative atrial fibrillation. Positive correlation was seen between the age and level of proBrain natriuretic peptide (r=0.322 and P=0.015). In multivariate analysis, age (P=0.05), lower ejection fraction (P=0.03), left atrial enlargement (P=0.05), longer P(max) (P=0.01) and P-wave dispersion (P=0.01) were found to be independent predictors of postoperative atrial fibrillation. CONCLUSION: Age, poor left ventricular functions, P(max) and P-wave dispersion are found to be independent predictors of atrial fibrillation after coronary artery bypass grafting.     

Postoperative atrial fibrillation and mortality after coronary artery bypass surgery

OBJECTIVES: We sought to determine if the occurrence of postoperative atrial fibrillation (AF) affects early or late mortality following coronary artery bypass surgery (CABG). BACKGROUND: Atrial fibrillation is the most common arrhythmia seen following CABG. METHODS: The Texas Heart Institute Cardiovascular Research Database was used to identify all patients that developed AF after isolated initial CABG from January 1993 to December 1999 (n = 994). This population was compared with patients who underwent CABG during the same period but did not develop AF (n = 5,481). In-hospital end points were adjusted using logistic regression models to account for baseline differences. Long-term survival was evaluated using a retrospective cohort design, where Cox proportional hazards methods were used to adjust for baseline differences, and with case-matched populations (n = 390, 195 per arm). RESULTS: Atrial fibrillation was diagnosed in 16% of the population. Postoperative AF was associated with greater in-hospital mortality (odds ratio [OR] 1.7, p = 0.0001), more strokes (OR 2.02, p = 0.001), prolonged hospital stays (14 vs. 10 days, p < 0.0001), and a reduced incidence of myocardial infarction (OR 0.62, p = 0.01). At four to five years, survival was worse in patients who developed postoperative AF (74% vs. 87%, p < 0.0001 in the retrospective cohort; 80% vs. 93%, p = 0.003 in the case-matched population). On multivariate analysis, postoperative AF was an independent predictor of long-term mortality (adjusted OR 1.5, p < 0.001 in the retrospective cohort; OR 3.4, p = 0.0018 in the case-matched population). CONCLUSIONS: The occurrence of AF following CABG identifies a subset of patients who have a reduced survival probability following CABG. The impact of various strategies, such as antiarrhythmics and warfarin, aimed at reducing AF and its complications deserves further study.     

Off-pump coronary artery bypass graft surgery: the incidence of postoperative atrial fibrillation

Atrial fibrillation (AF) occurs in one quarter to one third of patients after coronary artery bypass graft surgery (CABG). Conventional CABG uses cardiopulmonary bypass, a process that is itself associated with a systemic vascular inflammatory response that contributes to postoperative morbidity. The avoidance of cardiopulmonary bypass is associated with a significant reduction in the inflammatory response and in the release of markers of myocardial necrosis when compared with conventional CABG. There is speculation that off-pump CABG may reduce the incidence of postoperative AF through reduced trauma, ischaemia, and inflammation. Current data, however, do not emphatically answer the question of whether the incidence of post-CABG AF is reduced by off-pump surgery. The evidence from both observational and randomised studies is conflicting and many studies have weaknesses in design, conduct, or interpretation. It remains an attractive hypothesis that postoperative AF is reduced by off-pump CABG but more robust data are required.     

门冬氨酸钾镁在预防不停跳冠状动脉旁路移植术后心房纤颤发生的作用

目的:观察门冬氨酸钾镁在预防不停跳冠状动脉旁路移植(OPCABG)术后心房纤颤发生的作用。方法:所有入选160例患者均第1次接受OPCABG,且术前均为窦性心律。将患者随机分为试药组和对照组(每组80例)。试药组为术后3 d每天静脉内输注门冬氨酸钾镁4 g,对照组术后3 d每天输注安慰剂。排除标准:过去存在房颤病史,安装过心脏起搏器,术后心肌梗死,术中改为停跳搭桥的患者,肾功能不全患者。研究终点是术后发生房颤。结果:试药组房颤发生率为9%,对照组房颤发生率为19%,显著高于试药组(P0.01)。试药组ICU停留时间显著短于对照组[(2.6±1.3)d vs.(3.6±1.2)d,P0.05]。结论:术后连续3 d应用门冬氨酸钾镁可以安全有效减少OPCABG术后房颤的发生率。     

非体外冠脉搭桥术后新发房颤的相关危险因素分析

目的 分析非体外循环冠脉搭桥术后新发房颤发生的相关危险因素,为探讨预防及治疗术后新发房颤提供临床证据。方法 总结2010-2014年我院行非体外冠脉搭桥术患者135例,按照术后是否发生新发房颤分为房颤组与非房颤组,分别对各项临床数据进行统计学分析。结果 术后新发房颤发生率为24.44%(33例),房颤组患者年龄、术前合并心梗、左房内径、左室射血分数、术后氧分压、呼吸机辅助时间、术后钾离子水平、住院天数等较非房颤组有统计学差异。结论高龄、术前合并心梗、术后低氧血症、左房舒末内径增大为术后新发房颤的危险因素,非体外冠脉搭桥术后新发房颤会明显延长患者住院时间,应积极防治。     

Right coronary artery stenosis: An independent predictor of atrial fibrillation after coronary artery bypass surgery

Objectives. This study attempted to determine the importance of severe proximal right coronary artery disease as a predictor of atrial fibrillation in patients after coronary artery bypass surgery.Background. Studies in patients undergoing noncardiac surgery have suggested that ischemia in the right coronary artery distribution is associated with a high incidence of atrial fibrillation. However, the importance of right coronary artery disease as a predictor of atrial fibrillation after bypass surgery is unknown.Methods. The occurrence of sustained postoperative atrial fibrillation was studied prospectively in 168 consecutive patients undergoing coronary artery bypass grafting. Patients were followed up postoperatively until discharge. Severe right coronary artery stenosis was defined as ≥70% lumen narrowing.Results. Of 104 patients with proximal or mid right coronary artery stenosis, 45 (43%) had atrial fibrillation postoperatively compared with 12 (19%) of the 64 patients without significant right coronary disease (p = 0.001). Univariate predictors of atrial fibrillation included right coronary artery stenosis (p = 0.001), advancing age (p = 0.0001) and lack of beta-adrenergic blocking agent therapy after bypass surgery (p = 0.0004). Multivariate adjusted risk of developing atrial fibrillation after bypass surgery increased with the presence of severe right coronary artery disease (odds ratio 3.69, 95% confidence interval [CI] 1.61 to 8.48), advancing age (odds ratio 2.24/10 years, CI 1.48 to 3.41) and male gender (odds ratio 2.36, CI 1.01 to 5.49). The use of beta-blockers postoperatively was associated with a protective effect (odds ratio 0.4, CI 0.17 to 0.80).Conclusions. The presence of severe right coronary artery stenosis is an independent and powerful predictor of atrial fibrillation after coronary artery bypass surgery. In association with age, gender and postoperative beta-blocker therapy, these variables can be used to identify patients at increased risk for developing this arrhythmia.     

Effective prevention of atrial fibrillation by continuous atrial overdrive pacing after coronary artery bypass surgery

OBJECTIVES: The present study was aimed to evaluate the efficacy of a specific algorithm with continuous atrial dynamic overdrive pacing to prevent atrial fibrillation (AF) after coronary artery bypass graft (CABG) surgery. BACKGROUND: Atrial fibrillation occurs in 30% to 40% of patients after cardiac surgery with a peak incidence on the second day. It still represents a challenge for postoperative prevention and treatment and may have medical and cost implications. METHODS: Ninety-six consecutive patients undergoing CABG for severe coronary artery disease and in sinus rhythm without antiarrhythmic therapy on the second postoperative day were randomized to have or not 24 h of atrial pacing through temporary epicardial wires using a permanent dynamic overdrive algorithm. Holter ECGs recorded the same day in both groups were analyzed to detect AF occurrence. RESULTS: No difference was observed in baseline data between the two study groups, particularly for age, male gender, history of AF, ventricular function, severity of coronary artery disease, preoperative beta-adrenergic blocking agent therapy or P-wave duration. The incidence of AF was significantly lower (p = 0.036) in the paced group (10%) compared with control subjects (27%). Multivariate analysis showed AF incidence to increase with age (p = 0.051) but not in patients with pacing (p = 0.078). It decreased with a better left ventricular ejection fraction only in conjunction with atrial pacing (p = 0.018). CONCLUSIONS: We conclude that continuous atrial pacing with an algorithm for dynamic overdrive reduces significantly incidence of AF the second day after CABG surgery, particularly in patients with preserved left ventricular function.     

Effectiveness of triple-site triggered atrial pacing for prevention of atrial fibrillation after coronary artery bypass graft surgery

BACKGROUND: Recently, several temporary multisite pacing methods have been developed for prevention of postoperative atrial fibrillation (AF). HYPOTHESIS: In this study, we evaluated the effect of triple-site temporary triggered pacing in the AAT mode on the development of AF in patients undergoing coronary artery bypass graft (CABG) at high risk for developing postoperative AF. METHODS: A total of 70 patients undergoing CABG were randomly assigned either to pacing group (study group, n = 35 patients) or to no pacing group (control group, n = 35 patients). The external pacemaker was programmed to pace at the atrial triggered mode at a lower rate of 40 beats/min for 4 days. RESULTS: Atrial fibrillation, defined as lasting > 30 s, occurred in 4 patients (11.4%) in the study group and in 16 patients (45.7%) in the control group (p = 0.003). Sustained AF, defined as AF lasting > 10 min, also was observed less frequently in the study group than in the control group (11.6 vs. 37.1%, p = 0.024). Triple-site triggered atrial pacing was observed to reduce the incidence of AF by 75% and the incidence of sustained AF by 69%. CONCLUSIONS: We believe that multiple-site temporary pacing in the triggered mode is an effective way of preventing postoperative AF. This technique may be used especially in patients at high risk of developing AF.     

Right atrial overdrive pacing does not prevent atrial fibrillation after coronary artery bypass surgery.

AIMS: The purpose of this prospective randomized study was to investigate the efficacy of atrial overdrive pacing (AOP) and bradycardia prevention pacing (BPP) in the prophylaxis of atrial fibrillation (AF) after coronary artery bypass surgery (CABG). METHODS: One hundred and twenty-four on-pump CABG patients were randomized into three groups: AOP, BPP, and NP (no pacing). AOP patients were paced via epicardial wires using an atrial preference pacing algorithm, and BPP patients were paced in the AAI mode with a base rate of 60/min. Patients were paced for 48 h starting on the first postoperative day. The endpoint of the study was the first onset of AF lasting longer than 5 min. RESULTS: Preoperative risk factors and surgical data of patients did not differ between the AOP, BPP and NP groups. Pacing was technically successful in 80.5% of patients in the AOP and in 92.7% in the BPP groups. The incidence of AF in the AOP (26.8%), BPP (19.5%) and NP (28.6%) groups did not differ significantly. In the AOP group, AF in three patients was probably induced by inappropriate pacing due to sensing failure. CONCLUSIONS: Atrial overdrive pacing and bradycardia prevention pacing were not effective in the prevention of AF after CABG.     

冠状动脉搭桥术后早期新发房颤的临床研究进展

术后新发房颤（new-onset post-operative atrial fibrillation）是冠状动脉搭桥术后早期最常见的并发症之一,发病率为30％～50％,并随着患者年龄的增长而显著升高[1-7].术后新发房颤,特别是快速房颤,不仅会影响患者术后心功能,而且可使术后死亡率明显升高[1-3].近年来随着医学技术的不断发展,冠状动脉搭桥手术出现了如不停跳搭桥、微创小切口搭桥、机器人辅助搭桥等新的手术方式,不仅减轻了手术创伤,而且在一定程度上降低了术后并发症的发生率[8].     

Preoperative factors predisposing to early postoperative atrial fibrillation after isolated coronary artery bypass grafting

An analysis of 183 patients in sinus rhythm who underwent coronary artery bypass grafting was conducted to determine the association of multiple preoperative factors, including an elevated left ventricular end-diastolic pressure, with early postoperative atrial fibrillation. An association with advanced age, a history of atrial fibrillation, and preoperative digoxin use was found, but not with an elevated left ventricular end-diastolic pressure, irrespective of left ventricular systolic function.