Atrial fibrillation after minimally invasive direct coronary artery bypass surgery

OBJECTIVES: The study compared the adjusted risk for developing atrial fibrillation (AF) after minimally invasive direct coronary artery bypass surgery (MIDCAB) and coronary artery bypass graft surgery (CABG). BACKGROUND: Atrial fibrillation results in increased morbidity and delays hospital discharge after CABG. Recently, MIDCAB has been explored as an alternative to CABG. Because of differences in surgical approach between the two procedures, the incidence of AF may differ. METHODS: Randomly selected patients undergoing CABG and MIDCAB were examined. Baseline variables and postoperative course were recorded through review of medical record data. RESULTS: The MIDCAB patients were younger than CABG patients (64+/-12 vs. 67+/-10, p<0.04) and had less extensive coronary artery disease (53% of MIDCAB vs. 3% of CABG had single-vessel disease, while 15% of MIDCAB vs. 69% of CABG had triple-vessel disease, p<0.001 for overall group comparisons). No other differences in clinical or treatment data were noted. Postoperative AF occurred less often after MIDCAB (23% vs. 39%, p = 0.02). Other significant factors associated with postoperative AF included age (p = 0.0024), prior AF (p = 0.0007), left main disease (p = 0.01), number of vessels bypassed (p = 0.009), absence of postoperative beta-blocker therapy (p = 0.0001), and a serious postoperative complication (p = 0.0018). Because of differences between CABG and MIDCAB patients, multivariate logistic analysis was performed to determine independent predictors of postoperative AF. The type of surgery (CABG vs. MIDCAB) was no longer a significant predictor of postoperative AF (estimated relative risk for AF in CABG vs. MIDCAB patients: 1.57, 95% confidence interval (0.82-2.52). CONCLUSIONS: Although AF appears to be less common after MIDCAB than after CABG, the lower incidence is due to different clinical characteristics of patients undergoing these procedures.     

Clinical prediction rule for atrial fibrillation after coronary artery bypass grafting

OBJECTIVES: This study was designed to devise and validate a practical prediction rule for atrial fibrillation/atrial flutter (AF) after coronary artery bypass grafting (CABG) using easily available clinical and standard electrocardiographic (ECG) criteria. BACKGROUND: Reported prediction rules for postoperative AF have suffered from inconsistent results and controversy surrounding the added predictive value of a prolonged P-wave duration. METHODS: In 1,851 consecutive patients undergoing CABG with cardiopulmonary bypass, preoperative clinical characteristics and standard 12-lead ECG data were examined. Patients were continuously monitored for the occurrence of sustained postoperative AF while hospitalized. Multiple logistic regression was used to determine significant predictors of AF and to develop a prediction rule that was evaluated through jackknifing. RESULTS: Atrial fibrillation occurred in 508 of 1,553 patients (33%). Multivariate analysis showed that greater age (odds ratio [OR] 1.1 per year [95% confidence intervals (CI) 1.0 to 1.1], p < 0.0001), prior history of AF (OR 3.7 [95% CI 2.3 to 6.0], p < 0.0001), P-wave duration >110 ms (OR 1.3 [95% CI 1.1 to 1.7], p = 0.02), and postoperative low cardiac output (OR 3.0 [95% CI 1.7 to 5.2], p = 0.0001) were independently associated with AF risk. Using the prediction rule we defined three risk categories for AF: <60 points, 61 of 446 (14%); 60 to 79 points, 330 of 908 (36%); and >or=80 points, 117 of 199 (59%). The area under the receiver-operator characteristic curve for the model was 0.69. CONCLUSIONS: These data show that post-CABG AF can be predicted with moderate accuracy using easily available patient characteristics and may prove useful in prognostic and risk stratification of patients after CABG. The presence of intraatrial conduction delay on ECG contributed least to the prediction model.     

Role of preoperative atorvastatin administration in protection against postoperative atrial fibrillation following conventional coronary artery bypass grafting

Atrial fibrillation (AF) is one of the most common postoperative arrhythmias in patients who undergo coronary artery bypass grafting (CABG). The aim of this study was to evaluate the effect of preoperative atorvastatin on postoperative atrial fibrillation following coronary artery bypass grafting with cardiopulmonary bypass (CCABG). One hundred consecutive patients undergoing elective CCABG, without history of AF or previous statin treatment, were enrolled and randomly assigned to a statin group (atorvastatin 20 mg/d, n = 49) or a control group (placebo, n = 51) starting 7 days preoperatively. The primary endpoint was the occurrence of postoperative AF. C-reactive protein (CRP) levels were assessed in all selected patients before surgery and every 24 hours postoperatively until discharge from hospital. Atorvastatin significantly reduced the incidence of postoperative AF and postoperative peak CRP level versus placebo (18% versus 41%, P = 0.017; 129.3 ± 24.3 mg/L versus 149.3 ± 32.5 mg/L, P < 0.0001). Kaplan-Meier curves confirmed a significantly better postoperative atrial fibrillation-free survival in the statin group (χ(2) = 7.466, P = 0.006). Logistic regression analysis showed preoperative atorvastatin treatment was an independent factor associated with a significant reduction in postoperative AF (OR = 0.235, P = 0.007), whereas high postoperative CRP levels were associated with increased risk (OR = 2.421, P = 0.015). Preoperative atorvastatin administration may inhibit inflammatory reactions to prevent atrial fibrillation following coronary artery bypass grafting with cardiopulmonary bypass.     

Oral d,l sotalol reduces the incidence of postoperative atrial fibrillation in coronary artery bypass surgery patients: a randomized, double-blind, placebo-controlled study.

OBJECTIVES: The purpose of this prospective, randomized, double-blind, placebo-controlled study was to assess the efficacy of preoperatively and postoperatively administered oral d,l sotalol in preventing the occurrence of postoperative atrial fibrillation (AF). BACKGROUND: Atrial fibrillation is the most common arrhythmia following coronary artery bypass surgery (CABG). Its etiology, prevention and treatment remain highly controversial. Furthermore, its associated morbidity results in a prolongation of the length of hospital stay post-CABG. METHODS: A total of 85 patients, of which 73 were to undergo CABG and 12 CABG plus valvular surgery (ejection fraction > or = 28% and absence of clinical heart failure), were randomized to receive either sotalol (40 patients; mean dose = 190 +/- 43 mg/day) started 24 to 48 h before open heart surgery and continued for four days postoperatively, or placebo (45 patients, mean dose = 176 +/- 32 mg/day). RESULTS: Atrial fibrillation occurred in a total of 22/85 (26%) patients. The incidence of postoperative AF was significantly (p = 0.008) lower in patients on sotalol (12.5%) as compared with placebo (38%). Significant bradycardia/hypotension, necessitating drug withdrawal, occurred in 2 of 40 (5%) patients on sotalol and none in the placebo group (p = 0.2). None of the patients on sotalol developed Torsade de pointes or sustained ventricular arrhythmias. Postoperative mortality was not significantly different in sotalol versus placebo (0% vs. 2%, p = 1.0). Patients in the sotalol group had a nonsignificantly shorter length of hospital stay as compared with placebo (7 +/- 2 days vs. 8 +/- 4 days; p = 0.24). CONCLUSIONS: The administration of sotalol, in dosages ranging from 80 to 120 mg, was associated with a significant decrease (67%) in postoperative AF in patients undergoing CABG without appreciable side effects. Sotalol should be considered for the prevention of postoperative AF in patients undergoing CABG in the absence of heart failure and significant left ventricular dysfunction.     

Atrial fibrillation after beating heart surgery

Postoperative atrial fibrillation (AF) is a frequent adverse event after coronary artery bypass grafting (CABG) and may negatively affect the early clinical outcome. We sought to investigate the risk factors, prevalence, and prognostic implications of postoperative AF in patients submitted to CABG without cardiopulmonary bypass (off-pump). The study population comprised 969 patients, 645 men (67%) and 324 women (33%) who had off-pump CABG at the Washington Hospital Center from January 1987 to May 1999. Preoperative AF patients were excluded (n = 15). Two hundred six patients (age 69 +/- 10 years, 137 men [66%]) developed AF, whereas 763 patients (age 61 +/- 12 years, 508 men [67%]) did not. Predictors of AF included age >75 years (odds ratio [OR] 3.0, 95% confidence interval [CI] 1.9 to 4.5; p <0.001), history of stroke (OR 2.1, CI 1.2 to 3.7; p = 0. 007), postoperative pleural effusion requiring thoracentesis (OR 3.2, CI 1.0 to 9.4; p = 0.03), and postoperative pulmonary edema (OR 5.1, CI 1.2 to 21; p = 0.02). Minimally invasive direct CABG was associated with a lower incidence of AF (OR 0.4, CI 0.3 to 0.7; p <0. 001). AF was associated with a prolonged postoperative hospital stay (9 +/- 6 days AF vs 6 +/- 5 days no AF, p <0.001). In-hospital mortality was significantly higher in AF patients (3% AF vs 1% no AF, p = 0.009). Patients with persistent AF had a higher postoperative in-hospital stroke rate than patients without persistent AF (9% vs 0. 6%, p <0.001). AF after beating heart surgery is associated with a higher in-hospital morbidity, mortality, and prolonged hospital stay. A minimally invasive surgical approach (minimally invasive direct CABG) is associated with a lower risk of AF.     

Atrial fibrillation independently prolongs hospital stay after coronary artery bypass surgery

BACKGROUND: Atrial fibrillation (AF) is the most common arrhythmia occurring in patients after coronary artery bypass surgery (CABG). HYPOTHESIS: The purpose of this study was to determine whether AF independently prolonged postoperative length of stay (LOS). METHODS: Consecutive patients undergoing elective CABG were identified. Baseline clinical variables, postoperative course including the development of AF, and postoperative LOS were recorded. RESULTS: In all, 216 patients (aged 61 +/- 13 years) were examined. Postoperative LOS was 11.3 +/- 6.4 days (median LOS = 9 days). Fifty-five patients (25%) developed AF. Among 16 variables examined, the univariate predictors of LOS included age (p < 0.001), preoperative left ventricular ejection fraction (p < 0.001), absence of a prior smoking history (p < 0.05), bypass limited to venous conduits (p < 0.001), postoperative AF (p < 0.001), and the occurrence of a postoperative event (p < 0.001). Length of stay for patients who developed AF was significantly longer than that for patients who did not (15.1 +/- 9.0 vs. 10.0 +/- 4.6 days, p < 0.001). After adjusting for other significant variables, the occurrence of AF after CABG independently prolonged LOS: patients who developed AF stayed 3.2 +/- 1.7 days longer than patients who did not (p < 0.001). CONCLUSIONS: Atrial fibrillation lengthens hospital stay after CABG, and its effect is independent of other important variables. Identification of patients who are at risk for AF and successful treatment to prevent AF will likely contribute to major reductions in consumption of health care resources in patients with CABG.     

Role of postoperative use of adrenergic drugs in occurrence of atrial fibrillation after cardiac surgery

BACKGROUND: Use of adrenergic (inotropic and vasopressor) drugs is common after cardiac surgery. HYPOTHESIS: The study was undertaken to evaluate the role of postoperative adrenergic drug use as a predictor of postoperative atrial fibrillation (AF) after cardiac surgery. METHODS: The study population consisted of 199 patients post cardiac surgery. Postoperative adrenergic drug use and the baseline and clinical variables were analyzed as possible predictors of postoperative AF. RESULTS: Of 199 patients, postoperative AF occurred in 59 patients (incidence 30%). The adrenergic drugs were used in 127 (64%) patients. Postoperative AF occurred in 49 of the 127 patients (39%) with and in 10 of the 72 patients (14%) without adrenergic drug use (p < 0.01). By univariate analyses, postoperative adrenergic drug use, age, left ventricular hypertrophy, left atrial size, valve surgery, aortic valve replacement, cross clamp time, bypass time, postoperative ventricular pacing, and hours in intensive care unit were predictors of development of postoperative AF. Atrial pacing was a predictor of freedom from developing AF. By multivariate logistic regression analysis, adrenergic drug use was an independent predictor of postoperative AF (odds ratio [OR] 3.35, 95% confidence interval [CI] 1.38-8.12, p = 0.016). Two other independent predictors were valve surgery (OR 2.88, 95% CI 1.31-6.35, p = 0.002) and age (OR 10.73, 95% CI 10.37-11.10, p = 0.0001). Adrenergic drug use, valve surgery, ventricular pacing, and age were predictors of time duration from surgery to the occurrence of AF. Drugs with predominantly beta1-adrenergic receptor affinity were associated with a higher incidence of postoperative AF (dopamine 44%, dobutamine 41% vs. phenylepherine 20%, p = 0.001). CONCLUSION: Use of adrenergic drugs is an independent predictor of postoperative AF after cardiac surgery.     

Effect of race on the frequency of postoperative atrial fibrillation following coronary artery bypass grafting

Atrial fibrillation (AF) commonly complicates the postoperative course after coronary artery bypass grafting (CABG). Among the general population, African Americans have been shown to have a lower prevalence of AF than European Americans. Although many factors have been identified to predict risk for postoperative AF, race has not been examined. All patients aged ≥18 years who underwent CABG at Henry Ford Hospital during a 5-year period from January 1, 2004, to December 31, 2008, were included. Patients were excluded for any previous diagnosis of AF or if they had concomitant valve surgery at the time of CABG. The incidence of AF was determined by International Classification of Diseases, Ninth Revision, coding from postoperative hospitalization records. Overall, 1,001 patients were eligible for analysis. Of these, 731 (73%) were European American and 270 (27%) were African American. The African American group had a higher prevalence of hypertension (75.6% vs 58.8%, p <0.001) and heart failure (22.6% vs 15.7%, p = 0.01) and a trend toward a higher prevalence of diabetes mellitus (38.1% vs 33.4%, p = 0.159). Postoperative AF was diagnosed in 214 European Americans (29.3%) and 50 African Americans (18.5%) (p = 0.001). In multivariate analysis adjusting for age strata, gender, hypertension, diabetes, and heart failure, African Americans had less postoperative AF than European Americans, with an adjusted odds ratio of 0.539 (95% confidence interval 0.374 to 0.777, p = 0.001). In conclusion, African Americans have a significantly reduced incidence of AF compared to European Americans after CABG.     

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.     

Comparison of effectiveness and safety of ranolazine versus amiodarone for preventing atrial fibrillation after coronary artery bypass grafting

Atrial fibrillation (AF) is common after coronary artery bypass grafting (CABG) and increases the morbidity and cost. Amiodarone reduces AF after CABG. Ranolazine, an antianginal agent, also prolongs atrial refractoriness and inhibits after depolarizations and triggered activity; effects that could decrease AF after CABG. The present study compared amiodarone versus ranolazine for the prevention of AF after CABG. A retrospective cohort study of patients undergoing CABG at Aspirus Hospital from June 2008 to April 2010. The patients received either amiodarone (400 mg preoperatively followed by 200 mg twice daily for 10 to 14 days) or ranolazine (1,500 mg preoperatively followed by 1,000 mg twice daily for 10 to 14 days). The primary end point was any identified AF after CABG. A total of 393 consecutive patients undergoing CABG (mean age 65 ± 10 years, 72% men) received either amiodarone (n = 211 [53.7%]) or ranolazine (n = 182 [46.3%]). AF occurred in 26.5% of the amiodarone-treated patients compared to 17.5% of the ranolazine-treated patient (p = 0.035). The univariate predictors of AF included amiodarone use, age, chronic lung disease, and congestive heart failure. The multivariate predictors of AF included amiodarone use (odds ratio 1.7, 95% confidence interval 1.01 to 2.91, p = 0.045 vs ranolazine), age (odds ratio 2.2 per 10 years, 95% confidence interval 1.63 to 2.95, p <0.001), and chronic lung disease (odds ratio 1.86, 95% confidence interval 1.00 to 3.43, p = 0.049). No difference was found in the risk of adverse events between the 2 therapies. In conclusion, ranolazine was independently associated with a significant reduction of AF compared to amiodarone after CABG, with no difference in the incidence of adverse events. Randomized studies should be conducted to confirm these results.     

The role of P wave in prediction of atrial fibrillation after coronary artery surgery

Atrial fibrillation (AF) is a common arrhythmia after coronary artery bypass surgery (CABG). The purpose of this study was to determine the role of P wave duration, amplitude and dispersion in the prediction of AF after CABG. This study included 120 patients undergoing elective CABG. Clinical characteristics, 12-lead electrocardiogram (ECG), echocardiogram and coronary angiogram were obtained in all patients. We measured P wave duration, amplitude and dispersion from 12-lead ECG in each patient. After CABG, all patients were continuously monitored for AF attacks in the intensive care unit and ordinary ward. Our results showed that age greater than 60 years was the strongest predictor of postoperative AF (p<0.01), with a 3.7-fold greater likelihood of developing postoperative AF compared to ages less than 60 years. Gender was another independent predictor of postoperative AF, with men being 3.0 times more likely to develop postoperative AF compared to women (p = 0.03). The presence of prolonged P wave duration (> or =100 ms in lead II) was also an independent predictor (p = 0.04), with 2.9-fold greater risk of developing postoperative AF compared to a P wave duration of less than 100 ms. The P wave dispersion was similar between patients with and without postoperative AF (29+/-15 vs. 33+/-15 mm, p = NS). In conclusion, old age, male gender and prolonged P wave duration were independent predictors of AF after CABG. However, P wave dispersion and amplitude did not provide significant information in the prediction of postoperative AF.     

The relative importance of left atrial function versus dimension in predicting atrial fibrillation after coronary artery bypass graft surgery

Background Atrial fibrillation (AF) is a common complication after coronary artery bypass graft (CABG) surgery. The purpose of this study was to determine whether pre-existing left atrial dysfunction is a predictor of postoperative AF compared with other clinical predictors. Methods Ninety-three patients undergoing CABG were prospectively studied. Intraoperatively, transesophageal echocardiography was performed to measure left atrial size, transmitral flow velocity, and other routine parameters. Left atrial function was estimated by the following formula: Atrial index = Transmitral VTI total × LAEF/Left atrial maximal area (where VTI = velocity time integral of E and A waves, LAEF = left atrial ejection fraction). The association of potential clinical predictors with the occurrence of postoperative AF was evaluated by χ² or Fisher exact tests, followed by stepwise multivariate logistic regression model. P values and odds ratios (OR) with 95% CIs were reported. Significance was set at P < .05. Results Postoperative AF occurred in 28 of 93 patients (30.1%). Patients with postoperative AF were older (67.0 ± 8.3 vs 61.5 ± 9.6 years, P = .0075), had larger left atrial maximal area (14.3 ± 4.6 cm² vs 10.9 ± 4.3 cm², P < .001), lower atrial index (0.54 ± 0.56 vs 0.82 ± 0.64, P = .008), larger body surface area (BSA) (OR 57, 95% CI 3.97-827), longer aortic cross-clamp time (OR 1.03, 95% CI 1.00-1.05), and more likely to have a postoperative myocardial infarction (OR 3.28, 95% CI 0.99-10.87) compared with those without AF. By multivariate analysis, only age (OR 1.11, 95% CI 1.04-1.19, P = .002) and atrial dimension (OR 1.75, 95% CI 1.03-2.96, P = .038) were significant independent predictors of postoperative AF. Body surface area also increased the odds of postoperative AF, but the CI was wide (OR 114, 95% CI 4.65-2810, P = .004). Conclusions Our results demonstrate that age and atrial enlargement, rather than atrial function, were independent predictors of postoperative AF. (Am Heart J 2002;143:181-6.)     

Prognostic significance of atrial fibrillation is a function of left ventricular ejection fraction

BACKGROUND: Atrial fibrillation (AF) has been reported to be associated with decreased survival in population-based studies. Its prognostic importance in end-stage heart failure is not clear. METHODS AND RESULTS: We investigated the prognostic implications of AF as function of left ventricular (LV) ejection fraction (EF) in 8,931 consecutive patients undergoing echocardiography at our medical center between 1990 and 1999. Patient characteristics were: age 66 +/- 13 years, EF 51 +/- 15, AF in 1,203 patients. There were 1,911 deaths over a mean follow up of 913 days. The prevalence of AF was 11% in patients with normal left ventricular ejection fraction (LVEF) (EF >/= 55%, n = 5, 130), and 18% each in those with mild (EF 41-54%, n = 1209), moderate (EF 26-40%, n = 1183) and severe reductions in left ventricular ejection fraction (LVEF) (EF /= 450, raising a possibility of enhanced susceptibility of these patients. CONCLUSIONS: The effect of AF on mortality diminishes with worsening LV function and is absent in those with severe LV dysfunction. Susceptibility of patients with QT prolongation to AF mortality warrants further attention.     

围术期停用他汀对冠状动脉旁路移植术后心房颤动的影响

目的探讨常规接受他汀治疗的患者围术期停用他汀对冠状动脉旁路移植术(CABG)后心房颤动(AF)的影响。方法 207例CABG前已在服用他汀至少1个月的患者,按围术期是否停用他汀,随机分为他汀组(n=103)与停用他汀组(n=104)。分析比较两组患者术后AF发生情况及超敏C反应蛋白(hs-CRP)水平变化。结果两组在临床资料、围术期参数方面无显著差异(P>0.05)。停用他汀组AF发生率显著高于他汀组(30.8%vs13.6%),症状性AF发生率、AF持续时间、最快心室率亦均显著高于他汀组(P均<0.05)。多因素Logistic回归分析显示停用他汀是CABG后发生AF的独立危险因素(OR=2.9,95%CI:1.3～6.3,P=0.007)。hs-CRP水平在两组变化趋势相似,停用他汀组术后不同时间hs-CRP均显著高于他汀组(P均<0.05)。结论冠心病患者CABG围术期停用他汀可增加术后AF发生率,这可能与炎症反应反弹有关。     

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.     

Atrial fibrillation after coronary artery bypass grafting in elderly patients: incidence and risk factor analysis

OBJECTIVE: New-onset atrial fibrillation (AF) is the most frequent arrhythmic complication after coronary artery bypass grafting (CABG). Elderly patients who undergo this operation may have a different risk profile from the general population. The aim of this study was to identify risk factors for post-CABG AF in the elderly population. METHODS: Between September 2001 and December 2005, 426 elderly patients (age >/= 65 years) underwent CABG at our center. Ninety-one developed post-CABG AF (AF group), and the other 335 (no-AF group) did not develop this complication. Multivariate analysis (odds ratio, +/- 95 % CI, P value) was used to identify independent clinical predictors of post-CABG AF. RESULTS: The incidence of post-CABG AF in elderly patients during the study period was 21.4 %. Multivariate analysis identified age (OR 1.07, P < 0.009), age >/= 75 years (OR 1.77, P < 0.042), preoperative renal insufficiency (OR 5.09, P < 0.035), EuroSCORE (OR 1.18, P < 0.038), and cross-clamping time (OR 1.02, P < 0.012) as predictors of AF occurrence. The AF group had a significantly longer mean intensive care unit (ICU) stay (3.8 +/- 4.7 vs. 2.5 +/- 1.3 days for AF vs. no-AF; P = 0.0001), and a significantly higher proportion of patients with prolonged (>/= 6 days) ICU stays (8.8 % vs. 3.2 %, respectively; P = 0.033). Hospital mortality was 3.2 % in the no-AF group and 2.2 % in the AF group ( P = 0.74). CONCLUSION: This study of elderly patients reveals some novel predictors of post-CABG AF, most notably preoperative renal insufficiency and EuroSCORE. It is important to identify risk factors for post-CABG AF in all patient groups as this knowledge might lead to better prevention of this problem and its potential consequences.     

Histologic assessment of right atrial appendage myocardium in patients with atrial fibrillation after coronary artery bypass graft surgery

Atrial fibrillation (AF) is a common complication after coronary artery bypass graft (CABG) surgery. Despite the prevalence of AF occurring after cardiac surgery, its pathophysiology is incompletely understood. Our previous study demonstrated that age and left atrial enlargement were independent predictors of postoperative AF. Accordingly, the purpose of this study was to determine whether cellular changes such as fibrosis and/or hypertrophy occurred in the atrium in patients who subsequently developed postoperative AF. Right atrial appendage tissue was obtained during atriotomy in patients undergoing elective CABG surgery. Quantitative assessment of atrial fibrosis was performed with Sirius red stain, and atrial cell diameter was measured with the HE stain. Linear regression, t test, chi2 test or Fisher exact test were used for statistical analysis. Sixty-one patients (mean age 71 +/- 8 years) were studied. Increasing age was significantly associated with fibrosis (beta 0.3, 95% CI: 0.06-0.55, p = 0.017). The amount of right atrial fibrosis tended to correlate with the incidence of postoperative AF (p = 0.08). Cell diameter was not significantly different between patients with versus without postoperative AF (p = 0.85). These results suggest that the age-related atrial fibrosis rather than cellular hypertrophy may be important in the pathogenesis of AF after CABG surgery and should be further investigated.     

左心房容积与冠状动脉旁路移植术后心房颤动相关性的研究

目的:评价冠状动脉旁路移植术(CABG)前,二维超声心动图估测左心房容积指数(LAVI)与术后心房颤动发生的相关性。方法:入选北京同仁医院2010年1月至2012年6月期间,入院实施CABG术的冠心病患者106例进行前瞻性分析。将患者分为术后心房颤动组和术后未发生心房颤动组。采用多因素Logistic回归分析,评价术前通过二维超声心动图估测的LAVI值与术后心心房颤动动发生的相关性。结果:CABG术后发生心房颤动患者19例,术后心房颤动发生率为17.9%。术后心房颤动组的LAVI值显著高于术后未发生心房颤动组[(22.1±4.1)vs.(18.1±5.1)m L/m2,P=0.018]。多元logistic回归分析显示,年龄(OR=1.015,95%CI:1.017~1.0323,P=0.026)、高血压病史(OR=1.053,95%CI:1.019~1.087,P=0.009)、既往心房颤动病史(OR=2.273,95%CI:1.207~3.340,P=0.010)、LAV值(OR=1.784,95%CI:1.181~2.487,P=0.003)是CABG后心房颤动发生的独立危险因素。结论:CABG术前通过二维超声心动图估测的LAVI值是冠心病患者CABG术后心房颤动发生的独立危险因素,对于预测CABG术后心房颤动发生并进行危险分层具有一定参考价值。     

Value of preoperative echocardiography in the prediction of postoperative atrial fibrillation following isolated coronary artery bypass grafting

The value of echocardiography, especially tissue Doppler imaging (TDI), in the assessment of risk of postoperative atrial fibrillation (AF) after coronary artery bypass grafting (CABG) is not clear. One hundred two consecutive patients (80 men; mean age 61 +/- 10 years) who underwent elective isolated CABG were included in the study. All patients underwent conventional transthoracic echocardiography and TDI of the left and right heart before surgery. Also, 24-hour Holter recordings were obtained for all patients. The study end point was the development of postoperative AF. The surgical mortality rate was 2%. Postoperative AF occurred in 18 patients (18%). Patients with postoperative AF have been significantly older than patients without postoperative AF (73 +/- 7 vs 58 +/- 9 years, respectively; p <0.001). Compared with patients without postoperative AF, a significantly higher proportion of patients with postoperative AF experienced paroxysmal AF before surgery (6% vs 33%, respectively; p = 0.001). Patients with postoperative AF had a significantly larger mean left atrial diameter compared with patients without postoperative AF (37 +/- 3 vs 35 +/- 3 mm, respectively; p = 0.012). Multivariate logistic regression analysis identified age as the most significant predictor of postoperative AF (odds ratio 1.254, 95% confidence interval 1.127 to 1.396; p <0.001). Of the echocardiographic variables, only left atrial diameter was identified as a significant predictor of postoperative AF (odds ratio 1.250, 95% confidence interval 1.055 to 1.562; p = 0.047). In conclusion, in the prediction of postoperative AF after isolated CABG, preoperative transthoracic echocardiography, including both conventional echocardiography and TDI, is of little value.     

Relation between postoperative mortality and atrial fibrillation before surgical revascularization--3-year follow-up

BACKGROUND: Preoperative atrial fibrillation is one of the predictors of increased morbidity and mortality in patients undergoing surgical revascularization, and consequently, prolongs the duration of stay in the ICU and of overall hospitalization. METHODS: The study included 3000 patients subjected to primary isolated coronary artery bypass grafting from 2000 to 2004. Of the 3000 patients, 5.8 % (n = 174) had electrocardiographically documented, preoperative atrial fibrillation. To evaluate the relationship between preoperative AF and postoperative outcome, all patients were observed for about three years. RESULTS: Patients with preoperative atrial fibrillation were older (P < 0.05), had a lower ejection fraction (P < 0.001), a higher incidence of heart failure (P < 0.001), hypertension (P < 0.001), and more coexistent morbidities including diabetes (P < 0.05), obturative pulmonary disease (P < 0.0001) and mild renal failure (P < 0.001). Statistical analysis showed that survival rates at 6 and 30 days, 6 and 12 months, and 3 years following surgical revascularization of patients with vs. those without preoperative atrial fibrillation were: 96.4% vs. 98.1%, and 94.5% vs. 97.3% (P = ns), 86.2% vs. 93.0% (P < 0.03), and 74.7% vs. 91.0% (P < 0.02), and 70.7% vs. 90.6% (P < 0.01). After 3 years' observation there was a survival difference of 19.9%. We showed that preoperative atrial fibrillation triple increased the risk of postoperative AF and was an independent risk factor for in-hospital death (P < 0.001). CONCLUSIONS: Preoperative atrial fibrillation is a predictor of postoperative complications, including death, and of a significant reduction in patients' long-term survival. Patients with preoperative atrial fibrillation should be considered as high-risk patients with potential postoperative complications and should be well protected with antiarrhythmic and anticoagulant therapy.