Atrial fibrillation after non-cardiac surgery: P-wave characteristics and Holter monitoring in risk assessment.

BACKGROUND: We investigated the role of 12-lead ECG P-wave duration and dispersion and of Holter monitoring as predictors of post-thoracic surgery atrial fibrillation. METHODS: One hundred and five consecutive patients (88 males-17 females; age 60+/-9), undergoing thoracic surgery at National Cancer Institute between 2001 and 2003, were enrolled and both standard ECG and Holter monitoring were obtained from each patient. P-wave study was made on a magnified ECG paper copy. Holter monitoring was performed 1-3 days before surgery; patients were divided into three classes according to number and complexity of premature supra ventricular complexes (0: <30/h and no repetitive forms; 1: >30/h or couplets; 2: run of supraventricular tachycardia or atrial fibrillation). RESULTS: Atrial fibrillation was detected in 12 patients (11%) within 96 h from surgery. In univariable logistic model, P-wave duration was not associated with postoperative atrial fibrillation while P-wave dispersion and Holter monitoring demonstrated a statistically significant association with the occurrence of atrial fibrillation (OR of 30 vs 20 ms=2.06; CI: 1.17-3.64; p=0.012, OR of class 1-2 vs class 0=8.16; CI: 2.04-35.59; p=0.003, respectively). In the multivariable model, both P-wave dispersion and Holter were shown to be significantly associated with the end-point. Holter monitoring enhanced the predictive ability of P-wave dispersion (area under the ROC curve increased from 0.64 to 0.80). CONCLUSIONS: P-wave dispersion, but not duration, was associated with atrial fibrillation after thoracic surgery. Preoperative Holter monitoring adds further information and could be used to enhance the P-wave predictive power.     

Free triiodothyronine: a novel predictor of postoperative atrial fibrillation.

OBJECTIVE: Despite improved perioperative management, atrial fibrillation (AF) after coronary artery bypass grafting (CABG) remains a relevant clinical problem, whose pathogenetic mechanisms remain incompletely explained. A reduced incidence of postoperative AF has been described in CABG patients receiving IV tri-iodothyronine (T3). This study was designed to define the role of thyroid metabolism on the genesis of postoperative AF. METHODS AND RESULTS: Free T3 (fT3), free thyroxine (fT4), and thyroid stimulating hormone were assayed at admission in 107 consecutive patients undergoing isolated CABG surgery. Patients with thyroid disease or taking drugs known to interfere with thyroid function were excluded. A preoperative rhythm other than sinus rhythm was considered an exclusion criterion. Thirty-three patients (30.8%) had postoperative AF. An older age (P=0.03), no therapy with beta-blockers (P=0.08), chronic obstructive pulmonary disease (P=0.08), lower left ventricle ejection fraction (P=0.09) and lower fT3 concentration (P=0.001), were univariate predictors of postoperative AF. On multivariate analysis, low fT3 concentration and lack of beta-blocking therapy were independently related with the development of postoperative AF (odds ratio, OR, 4.425; 95% confidence interval, CI, 1.745-11.235; P=0.001 and OR 3.107; 95% CI 1.087-8.875; P=0.03, respectively). Postoperative AF significantly prolonged postoperative hospital stay (P=0.002). CONCLUSIONS: Low basal fT3 concentration can reliably predict the occurrence of postoperative AF in CABG patients.     

Atrial fibrillation after cardiac surgery: a major morbid event?

OBJECTIVE: The purpose of the study was to investigate the incidence, predictors, morbidity, and mortality associated with postoperative atrial fibrillation (AF) and its impact on intensive care unit (ICU) and postoperative hospital stay in patients undergoing cardiac surgery in the Department of Veterans Affairs (VA). SUMMARY BACKGROUND DATA: Postoperative AF after open cardiac surgery is rather common. The etiology of this arrhythmia and factors responsible for its genesis are unclear, and its impact on postoperative surgical outcomes remains controversial. The purpose of this special substudy was to elucidate the incidence of postoperative AF and the factors associated with its development, as well as the impact of AF on surgical outcome. METHODS: The study population consisted of 3855 patients who underwent open cardiac surgery between September 1993 and December 1996 at 14 VA Medical Centers. Three hundred twenty-nine additional patients were excluded because of lack of complete data or presence of AF before surgery, and 3794 (98.4%) were male with a mean age of 63.7+/-9.6 years. Operations included coronary artery bypass grafting (CABG) (3126, 81%), CABG + AVR (aortic valve replacement) (228, 5.9%), CABG + MVR (mitral valve replacement) (35, 0.9%), AVR (231, 6%), MVR (41, 1.06%), CABG + others (95, 2.46%), and others (99, 2.5%). The incidence of postoperative AF was 29.6%. Multivariate logistic regression analysis of factors found significant on univariate analysis showed the following predictors of postoperative AF: preoperative patient risk predictors: advancing age (odds ratio [OR] 1.61, 95% confidence interval [CI] 1.48-1.75, p < 0.001), chronic obstructive pulmonary disease (OR 1.37, 95% CI 1.12-1.66, p < 0.001), use of digoxin within 2 weeks before surgery (OR 1.37, 95% CI 1.10-1.70, p < 0.003), low resting pulse rate <80 (OR 1.26, 95% CI 1.06-1.51, p < 0.009), high resting systolic blood pressure >120 (OR 1.19, 95% CI 1.02-1.40, p < 0.026), intraoperative process of care predictors: cardiac venting via right superior pulmonary vein (OR 1.42, 95% CI 1.21-1.67, p < 0.0001), mitral valve repair (OR 2.86, 95% CI 1.72-4.73, p < 0.0001) and replacement (OR 2.33, 95% CI 1.55-3.55, p < 0.0001), no use of topical ice slush (OR 1.29, 95% CI 1.10-1.49, p < 0.0009), and use of inotropic agents for greater than 30 minutes after termination of cardiopulmonary bypass (OR 1.36, 95% CI 1.16-1.59, p < 0.0001). Postoperative median ICU stay (3.6 days AF vs. 2 days no AF, p < 0.001) and hospital stay (10 days AF vs. 7 days no AF, p < 0.001) were higher in AF. Morbid events, hospital mortality, and 6-month mortality were significantly higher in AF (p < 0.001): ICU readmission 13% AF vs. 3.9% no AF, perioperative myocardial infarction 7.41 % AF vs. 3.36% no AF, persistent congestive heart failure 4.57% AF vs. 1.4% no AF, reintubation 10.59% AF vs. 2.47% no AF, stroke 5.26% AF vs. 2.44% no AF, hospital mortality 5.95% AF vs. 2.95% no AF, 6-month mortality 9.36% AF vs. 4.17% no AF. CONCLUSIONS: Atrial fibrillation after cardiac surgery occurs in approximately one third of patients and is associated with an increase in adverse events in all measurable outcomes of care and increases the use of hospital resources and, therefore, the cost of care. Strategies to reduce the incidence of AF after cardiac surgery should favorably affect surgical outcomes and reduce utilization of resources and thus lower cost of care.     

冠状动脉旁路移植术后早期新发心房颤动的临床特征及影响因素分析

目的 探讨冠状动脉旁路移植术后新发心房颤动(房颤)的临床特征及影响因素.方法 回顾性分析2012年1月至2019年1月在我院行冠状动脉旁路移植术的339例患者的临床资料,其中男267例、女72例,年龄37～83(58.03±8.90)岁.分析术后新发房颤的临床特征及影响因素.结果 不停跳冠状动脉旁路移植(off-pum...     

Relation of inflammatory cytokines to atrial fibrillation after off-pump coronary artery bypass grafting.

OBJECTIVE: It has been observed that a systemic inflammatory response after on-pump coronary artery bypass grafting (CABG) participates in the pathogenesis of postoperative atrial fibrillation (AF). In patients undergoing off-pump CABG, it is plausible that inflammation is associated with the development of postoperative AF. The present study examined relation of proinflammatory cytokines, which play an important role in the upstream of inflammatory cascade, to the development of AF after off-pump CABG. METHODS: The present study included 39 patients undergoing off-pump CABG. Tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-6, and IL-8, were measured by enzyme-linked immunosorbent assay, on anesthetic induction, after sternotomy before anastomoses, at the completion of anastomoses, 3 and 6h thereafter, and on postoperative days (POD) 1-4. C-reactive protein (CRP) was also measured by turbidimetric immunoassay, preoperatively, and on POD 1, 2, 3, 6, 9, and 13. RESULTS: Eleven patients (28%) developed postoperative AF. Patients with postoperative AF were older (70+/-6.4 years vs 60+/-8.8 years, P=0.001); however, there was no difference in other pre- and perioperative variables. TNF-alpha level did not change during the study period. However, IL-8 and CRP levels significantly increased after the surgery, although there was no significant difference between the two groups. IL-6 level also increased after the surgery with its peak at 6h after the completion of anastomoses. IL-6 levels of 3 and 6h after anastomoses were significantly higher in patients with postoperative AF (360+/-143 pg/ml vs 230+/-94 pg/ml, P=0.0047, 435+/-175 pg/ml vs 247+/-102 pg/ml, P=0.0005, respectively). Logistic regression analysis indicated that the highest quartile of IL-6 level immediately after the surgery (odds ratio 7.63; 95% CI, 1.06-54.9; P=0.04) and age (odds ratio 1.18; 95% CI, 1.01-1.39; P=0.04) independently predict postoperative AF. Furthermore, the maximum level of IL-6 immediately after the surgery significantly correlated to age and intraoperative blood loss (r=0.04, P=0.01, and r=0.47, P=0.04, respectively). CONCLUSIONS: Advanced age was a major risk factor for postoperative AF. Furthermore, inflammatory response induced by surgical trauma was also associated with the development of AF after off-pump CABG.     

Postoperative white blood cell count predicts atrial fibrillation after cardiac surgery

BACKGROUND: Postoperative atrial fibrillation (AF) occurs in as many as 50% of cardiac surgery patients and represents the most common postoperative rhythm complication. The cause of AF after cardiac surgery is incompletely understood, and its prevention remains suboptimal. Currently the role of inflammation and oxidative stress on electrical remodeling is under investigation, and recent studies have demonstrated that C-reactive protein levels are elevated in AF. The purpose of the present study was to investigate the correlation between the postoperative white blood cell (WBC) count as a marker of inflammation and the development of postoperative AF after cardiac surgery. METHODS AND RESULTS: Patients undergoing elective cardiac surgery in the absence of significant left ventricular dysfunction (n = 253; average age, 65 +/- 11 years) were recruited to the present prospective study. Atrial fibrillation developed during the postoperative period in 99 patients (39.1%) of the total study population. The WBC count was prospectively assessed in all patients to determine the predictive value of baseline and postoperative WBC count on development of postoperative AF. Baseline WBC count was 6.8 +/- 1.9 x 10(9)/L and 6.8 +/- 2.2 x 10(9)/L (p = 0.95), respectively, in patients with and without postoperative AF; and postoperative peak WBC count was 16.3 +/- 6.5 x 10(9)/L and 15 +/- 4.2 x 10(9)/L (p = 0.048), respectively, in patients without postoperative AF. However, neither baseline nor peak monocyte count differed significantly among patients with and without postoperative AF: 0.43 +/- 0.15 x 10(9)/L and 0.46 +/- 0.46 x 10(9)/L (p = 0.5), and 0.91 +/- 0.3 x 10(9)/L and 0.93 +/- 0.4 x 10(9)/L (p = 0.8), respectively. In addition to a more pronounced increase in peak WBC count (above v below median; odds ratio [OR], 1.8; 95% confidence interval [CI], 1.1-2.7; p < 0.05), increasing age (above v below median; OR, 2.6; CI, 1.2-3.9; p < 0.01), surgery for valvular heart disease versus coronary artery bypass grafting (OR, 2.8; CI, 1.1-3.5; p < 0.01), development of postoperative complications, such as stroke, infections, or unstable hemodynamics (OR, 1.9; CI, 1.0-7.5; p < 0.05), and perioperative nonuse of beta-adrenergic blockers (OR, 1.7; CI, 1.1-4.9; p < 0.05) were identified as independent predictors of postoperative AF by multivariate logistic regression analysis. CONCLUSIONS: Cardiac surgery is associated with an elevated postoperative WBC count that represents a common marker of inflammation. A more pronounced increase in postoperative WBC count independently predicts development of postoperative AF. These data provide additional evidence to support the association between the inflammatory response and postoperative AF.     

A 5-year clinical experience with bipolar radiofrequency ablation for permanent atrial fibrillation concomitant to coronary artery bypass grafting and aortic valve surgery

This study analyses the 5-year results of permanent atrial fibrillation (pAF) bipolar radiofrequency (RF) ablation surgery concomitant to coronary artery bypass grafting (CABG) and/or aortic valve (AV) surgery. Eighty-five patients with pAF (0.5-30 years) underwent bipolar RF ablation procedure concomitant to CABG/AV surgery. All patients were restudied to assess survival, conversion rate to stable sinus rhythm (SR) and New York Heart Association (NYHA) class at 8+/-1 days and at 3+/-1 and 32+/-15 months after surgery. Survival at time of re-examination was 100%, 98% and 96%, respectively (three non-cardiac deaths), SR could be documented in 61%, 74% and 78% of patients. Long-term AF before surgery and larger size of the left atrium (LA) were predictive for postoperative AF return (P=0.005, P=0.03); 88% of patients with small preoperative LA-size (<50 mm) and 85% with pAF-duration time <5 years had stable SR at late follow-up. Cardiac rhythm at three months was predictive for long-term rhythm-prognosis (P<0.0001). NYHA-class improved significantly after surgery (P<0.0005), particularly when SR was achieved (P=0.046). Permanent AF bipolar RF ablation surgery revealed excellent results in AV/CABG patients. It could be demonstrated that established SR remained stable over time. Preoperative pAF-duration time and LA-size are useful variables to predict the success rate of ablation.     

The association of patent foramen ovale and atrial fibrillation after coronary artery bypass graft surgery

Atrial fibrillation (AF) is associated with considerable morbidity and increased resource utilization after coronary artery bypass graft surgery. In this study, we sought to determine whether patent foramen ovale (PFO) and atrial septal aneurysm are associated with an increased risk of postoperative AF in this patient population. We performed a database study on 1008 patients undergoing primary coronary artery bypass graft surgery. All patients were assessed for the development of postoperative AF from the day of surgery to hospital discharge. Atrial septal defects were identified during comprehensive intraoperative transesophageal echocardiographic examination. Postoperative AF was present in 124 (12.3%) patients. Patients with AF were significantly older and had a more frequent incidence of preoperative congestive heart failure, longer cross-clamp time, and prolonged hospital length of stay. PFO was present in 72 (7.1%) and atrial septal aneurysm in 23 (2.3%) patients. In these patients, postoperative AF was present in 14 (19.4%) patients with PFO and 8 (34.8%) patients with atrial septal aneurysm. Multivariate logistic regression analysis identified that PFO (odds ratio [OR], 1.95; 1.007-3.778; P = 0.047), age (OR, 1.03; 1.015-1.053; P = 0.0004), and history of congestive heart failure (OR, 2.55; 1.671-3.900; P < 0.0001) were predictive of postoperative AF. IMPLICATIONS: The presence of patent foramen ovale is associated with new-onset postoperative atrial fibrillation after coronary artery bypass graft surgery. This finding requires further validation in future prospective trials.     

Relationship between left atrial volume and atrial fibrillation following coronary artery bypass grafting

Abstract Background: Atrial fibrillation (AF) is a common complication of coronary artery bypass grafting (CABG). However, limited information is available about the role of preoperative echocardiographic left atrial evaluation to predict AF occurrence after CABG. Thus, we prospectively compared the ability of echocardiographic measurements of left atrial volume to predict AF in this setting. Methods: From January to December 2009, 220 patients (75% males, 66.8 ± 10.0 years) met the inclusion criteria of our study (isolated and elective CABG, no valve surgery, no permanent AF, or other chronic atrial arrhythmias). The day before CABG a complete echocardiographic evaluation was performed with left atrial volume measurements. The primary endpoint of the study was postoperative AF (POAF) lasting >30 seconds. Results: POAF was observed in 61 patients (27.7%). POAF patients showed increased left atrial M‐mode anteroposterior dimension (41.2 ± 6.4 mm vs. 43.6 ± 7.3 mm; p = 0.020) and increased left atrial volume (59.0 ± 18.3 mL vs. 70.6 ± 28.1 mL; p = 0.0004). Left atrial volume was an independent risk factor for POAF (OR 10.03; 95% CI 10.01 to 10.05; p = 0.01), along with postoperative bleeding with hemoglobin levels below 8 g/dL (OR 20.84; 95% CI 10.12 to 70.19; p = 0.03) and preoperative left ventricular ejection fraction below 40% (OR 10.08; 95% CI 10.01 to 10.15; p = 0.02). Conversely, preoperative statin therapy exerted a protective role (OR 0.30; 95% CI 0.12 to 0.74; p = 0.009). Conclusion: Preoperative echocardiographic evaluation of patients with isolated CABG demonstrated that left atrium volume measurements were independently correlated to the occurrence of POAF. Further investigations should focus on the opportunity to target prophylactic antiarrhythmic treatments to patients with large left atrial volumes. (J Card Surg 2012;27:128–135)     

Myocardial protection with insulin cardioplegia: who can really benefit?

AIM: The aim of the study was to evaluate the effects on myocardial protection of insulin-enriched warm blood cardioplegia (IWBC) in coronary artery bypass grafting (CABG) and in subgroups of patients with associated cardiac co-morbidities. METHODS: Between May 2000 and December 2002, 268 consecutive patients underwent CABG with warm blood cardioplegia (group A) or IWBC (10 UI/L) (group B). Hospital outcome, ECG, echocardiography and biochemical markers of ischemia were compared. Differences between subgroups of patients with unstable angina (UA), ventricular hypertrophy (VH) and diabetes were assessed. RESULTS: Hospital mortality, incidence of postoperative myocardial infarction and low output syndrome, IABP requirement, postoperative atrial fibrillation, in-hospital and in-ITU stay, postoperative recovery of left ventricular function and enzyme leakage did not show differences between the 2 groups; inotropic support was lower in IWBC. Moreover, patients with UA and IWBC showed a lower troponin I (TnI) (12 h: 0.82+/-0.57 ng/mL vs 2.56+/-1.18, P < 0.0001; 24 h: 0.71+/-0.64 vs 2.16+/-1.52, P < 0.0001; 48 h: 0.69+/-1.13 vs 1.79+/-1.43, P = 0.001; 72 h: 0.44+/-0.83 vs 1.01+/-1.02, P = 0.001), lower incidence of atrial fibrillation (4.2% versus 60.6%; P < 0.0001) and intraoperative defibrillation (0% versus 27.3%; P = 0.007). Furthermore, patients with VH treated with IWBC showed lower level of TnI (12 h: 0.41+/-0.32 ng/mL vs 2.93+/-0.67, P < 0.0001; 24 h: 0.37+/-0.45 vs 2.40+/-1.28, P < 0.0001; 48 h: 0.22+/-0.18 vs 1.95+/-1.33, P < 0.0001; 72 h: 0.12+/-0.12 vs 1.31+/-1.56, P < 0.0001), lower atrial fibrillation (6.5% vs 48%, P < 0.0001) and ventricular defibrillation (0% vs 20%, P = 0.011). CONCLUSIONS: Insulin addiction to blood cardioplegia does not show any benefit in the global population and in diabetics; nevertheless, better myocardial protection can be demonstrated in patients with unstable angina and left ventricular hypertrophy.     

Signal-averaged P-wave Duration Does Not Predict Atrial Fibrillation after Thoracic Surgery

Background: Atrial fibrillation (AF) is the most common dysrhythmia seen early after major thoracic surgery but occurs infrequently after minor thoracic or other operations. A prolonged signal-averaged P-wave duration (SAPWD) has been shown to be an independent predictor of AF after cardiac surgery. The authors sought to determine whether a prolonged SAPWD alone or in combination with clinical or echocardiographic correlates predicts AF after elective noncardiac thoracic surgery.

Methods: Of the 250 patients enrolled, 228 were included in the final analysis. Preoperative SAPWD was obtained in 155 patients who had major thoracic surgery and in 73 patients undergoing minor thoracic or other operations who served as comparison control subjects. The SAPWD was recorded from three orthogonal leads using a sinus P-wave template. The filtered vector composite was used to measure total P-wave duration. Clinical, surgical, and echocardiographic parameters were collected and patients followed for 30 days after surgery for the development of symptomatic AF.

Results: Symptomatic AF developed in 18 of 155 (12%) patients undergoing major thoracic surgery and in 1 of 73 (1%) patients having minor thoracic or abdominal surgery, most commonly 2 or 3 days after surgery. In comparison with similar patients undergoing major thoracic surgery without AF, those who developed AF were older (66 +/- 8 vs. 62 +/- 10 yr; P = 0.04) but did not differ in SAPWD (145 +/- 17 vs. 147 +/- 16, ms) in standard electrocardiographic P-wave duration (105 +/- 7 vs. 107 +/- 10 ms), incidence of left-ventricular hypertrophy on 12-lead electrocardiography, male sex, history of hypertension, diabetes, or coronary heart disease. Thoracic-surgery patients at risk for postoperative AF did not differ from all other patients at low risk for AF in clinical or SAPWD parameters.     

Atrial fibrillation and plasma troponin I elevation after cardiac surgery: relation to inflammation-associated parameters

BACKGROUND: Recent studies have demonstrated correlation between inflammation to plasma troponin (cTnI) levels elevation and atrial fibrillation (AF) in noncardiac surgery settings. The goal of this prospective study was to examine the relation between inflammation associated parameters (IAPs) to post cardiac surgery cTnI elevation and AF. METHODS: A single post CABG cTnI measurement was assessed in 156 consecutive patients. Clinical, operative and postoperative data, IAPs (hypophosphatemia, preoperative statin treatment, immediate postoperative fever, and prolonged mechanical ventilation) and in-hospital AF episodes were prospectively recorded. RESULTS: Mean cTnI level was 14.4 +/- 12.4 ng/mL. In the two in-hospital deaths (1.2%) cTnI concentration was less than 12 ng/mL. Cardiac troponin-I levels were significantly higher in patients not preoperatively treated with statins (21.6 +/- 4.1 vs. 13.3 +/- 0.9, p = 0.05), in patients who needed intraoperative cardioversion (16.7 +/- 2.2 vs. 12.2 +/- 0.9, p = 0.07), in patients with postoperative hypophosphatemia (16.9 +/- 10.0 vs. 11.1 +/- 13.7, p = 0.04), postoperative fever (18.6 +/- 3.0 vs. 13.7 +/- 1.0, p = 0.07) and postoperative respiratory complications (23.9 +/- 4.3 vs. 13.5 +/- 1.0, p = 0.04). Step-wise logistic regression analysis revealed the following parameters as independently associated with elevated cTnI levels: preoperative statin treatment (CI 95%-15.9; -1.7, p = 0.02), intraoperative ventricular arrhythmia (CI 95%-0.7; 13.8, p = 0.08), hypophosphatemia (CI 95% 0.9; 8.6, p = 0.02), postoperative fever (CI 95% 0.9; 11.0, p = 0.02), and postoperative respiratory complications (CI 95% 0.1; 0.5, p = 0.01). Of the 156 patients, 50 (32.1%) had postoperative AF. The first episode of AF occurred between postoperative day 1 and 6 (mean-day 2). Mean duration of AF was 21.8 +/- 8.1 hours. Postoperative AF was significantly associated with age above 75 (50% vs. 29.4%, p = 0.01), hypertension (37% vs. 18%, p = 0.02), preoperative calcium channel blockers treatment (44% vs. 26%, p = 0.02), furosemide treatment (58% vs. 30%, p = 0.05), and preoperative left atrial diameter above 40 mm (56% vs. 29%, p = 0.01). Postoperatively, AF was significantly associated with postoperative renal failure (70% vs. 29%, p = 0.01), respiratory complications (61% vs. 29%, p = 0.02), and prolonged hospital stay (OR 1.1; CI 1.0-1.3; p < 0.05). No association was found between troponin levels and postoperative AF. Multivariable analysis found only left atrial enlargement and prolonged hospital stay independently associated with AF. CONCLUSIONS: A significant correlation between clinical IAPs and cTnI plasma level elevation was found after cardiac surgery. There was no correlation between these parameters and postoperative AF, and there was no correlation between postoperative plasma cTnI levels and the occurrence of AF. Preoperative treatment with statins may be beneficial in reducing postoperative inflammatory response but further study has to be carried out.     

Risk factors of postoperative atrial fibrillation after cardiac surgery

BACKGROUND: Postoperative atrial fibrillation (AF) occurs in up to 50% of cardiac surgery patients and represents the most common postoperative arrhythmic complication. The etiology of AF after open-heart surgery is incompletely understood and its prevention remains suboptimal. Identification of patients vulnerable for postoperative AF would allow targeting of those most likely to benefit from aggressive prophylactic intervention. The aim of the present study was to evaluate clinical predictors of postoperative AF. METHODS AND RESULTS: Patients undergoing elective cardiac surgery in the absence of significant left ventricular dysfunction (n = 253; average age 65 +/- 11 years) were recruited to the present prospective study. Ninety-nine patients (39.1%) of the total study population developed AF during the postoperative period. The median age for patients with postoperative AF was 69 years compared with 64 years for patients without (p < 0.001). In addition to advanced age, AF patients were more likely to have surgery for valvular heart disease and less likely to have preoperative beta-adrenergic blockers than patients without AF. Multivariate logistic regression analysis (odds ratio, +/-95% CI, p value) was used to identify the following independent clinical predictors of postoperative AF: increasing age (above vs. below median [OR = 2.6; CI, 1.2 to 3.9; p < 0.01]), and surgery for valvular heart disease (vs. coronary artery bypass grafting [OR 2.8; CI, 1.1 to 3.5; p < 0.01)]). Additionally, postoperative complications (stroke, infections, unstable hemodynamics [OR = 1.9; CI, 1.0 to 7.5; p < 0.05]), and preoperative nonuse of beta-adrenergic blockers (OR = 1.7; CI, 1.1 to 4.9; p < 0.05) were associated with increased risk for postoperative AF. Both, patients with and without AF had similar body mass index, preoperative heart rate, preoperative blood pressure, and duration of surgery. Male sex did not identify patients at high risk for development of AF after cardiac surgery. CONCLUSIONS: Postoperative AF remains the most common complication after cardiac surgery. A combination of advanced age and type of surgery identifies patients at high risk for development of AF after cardiac surgery.     

Older age is the strongest predictor of postoperative atrial fibrillation

BACKGROUND: Identification of patients vulnerable for atrial fibrillation (AF) after major thoracic surgery will allow targeting those most likely to benefit from prophylactic therapy. The goal of the current study was to evaluate the accuracy of easily available clinical characteristics for the prediction of this complication. METHODS: Patients undergoing major elective thoracic surgery were chosen from an ongoing prospective database. RESULTS: Postoperative in-hospital AF occurred in 79 (15%) of 527 patients Using cut-point methodology and logistic regression, the authors identified two preoperative risk factors independently associated with AF: age 60 yr or older (P = 0.0007) and heart rate 74 beats/min or greater on preadmission electrocardiogram (P = 0.005). The odds of developing AF increased by a factor of 2.5 (95% confidence interval, 1.7-3.4; P < 0.0001) between incremental age categories (< 60 yr, 60-69 yr, > or = 70 yr) and by a factor of 2.3 (95% confidence interval, 1.4-3.8; P < 0.0007) between heart rate categories (< 74 beats/min, > or = 74 beats/min). The combination of age 60 yr or older and preoperative heart rate 74 beats/min or greater predicted AF with a sensitivity of 73% and specificity of 57%. Maximum P-wave duration as measured from standard electrocardiogram did not differentiate patients who did or did not develop AF. Patients who developed AF had a higher incidence of postoperative pneumonia (14 vs. 4%; P = 0.001), acute respiratory failure (8 vs. 1.6%; P = 0.01), greater hospital stay (17 +/- 17 vs. 10 +/- 9 days; P = 0.001) and 30-day mortality (11 vs. 3%; P = 0.001) when compared with those who did not develop AF, respectively. CONCLUSIONS: Advanced age and preoperative heart rate identify patients at high risk for development of AF after thoracic surgery. Postoperative AF occurs more frequently in patients with greater postoperative morbidity and length of hospitalization.     

Signal-averaged P-wave duration does not predict atrial fibrillation after thoracic surgery.

BACKGROUND: Atrial fibrillation (AF) is the most common dysrhythmia seen early after major thoracic surgery but occurs infrequently after minor thoracic or other operations. A prolonged signal-averaged P-wave duration (SAPWD) has been shown to be an independent predictor of AF after cardiac surgery. The authors sought to determine whether a prolonged SAPWD alone or in combination with clinical or echocardiographic correlates predicts AF after elective noncardiac thoracic surgery. METHODS: Of the 250 patients enrolled, 228 were included in the final analysis. Preoperative SAPWD was obtained in 155 patients who had major thoracic surgery and in 73 patients undergoing minor thoracic or other operations who served as comparison control subjects. The SAPWD was recorded from three orthogonal leads using a sinus P-wave template. The filtered vector composite was used to measure total P-wave duration. Clinical, surgical, and echocardiographic parameters were collected and patients followed for 30 days after surgery for the development of symptomatic AF. RESULTS: Symptomatic AF developed in 18 of 155 (12%) patients undergoing major thoracic surgery and in 1 of 73 (1%) patients having minor thoracic or abdominal surgery, most commonly 2 or 3 days after surgery. In comparison with similar patients undergoing major thoracic surgery without AF, those who developed AF were older (66+/-8 vs. 62+/-10 yr; P = 0.04) but did not differ in SAPWD (145+/-17 vs. 147+/-16, ms) in standard electrocardiographic P-wave duration (105+/-7 vs. 107+/-10 mns), incidence of left-ventricular hypertrophy on 12-lead electrocardiography, male sex, history of hypertension, diabetes, or coronary heart disease. Thoracic-surgery patients at risk for postoperative AF did not differ from all other patients at low risk for AF in clinical or SAPWD parameters. CONCLUSIONS: Under the conditions of this study, SAPWD did not differentiate patients who did or did not develop AF after noncardiac thoracic surgery, and therefore its measurement cannot be recommended for the routine evaluation of these patients. Older age continues to be a risk factor for AF after thoracic surgery.     

Older Age Is the Strongest Predictor of Postoperative Atrial Fibrillation

Background: Identification of patients vulnerable for atrial fibrillation (AF) after major thoracic surgery will allow targeting those most likely to benefit from prophylactic therapy. The goal of the current study was to evaluate the accuracy of easily available clinical characteristics for the prediction of this complication.

Methods: Patients undergoing major elective thoracic surgery were chosen from an ongoing prospective database.

Results: Postoperative in-hospital AF occurred in 79 (15%) of 527 patients Using cut-point methodology and logistic regression, the authors identified two preoperative risk factors independently associated with AF: age 60 yr or older (P = 0.0007) and heart rate 74 beats/min or greater on preadmission electrocardiogram (P = 0.005). The odds of developing AF increased by a factor of 2.5 (95% confidence interval, 1.7-3.4;P < 0.0001) between incremental age categories (< 60 yr, 60-69 yr, >= 70 yr) and by a factor of 2.3 (95% confidence interval, 1.4-3.8;P < 0.0007) between heart rate categories (< 74 beats/min, >= 74 beats/min). The combination of age 60 yr or older and preoperative heart rate 74 beats/min or greater predicted AF with a sensitivity of 73% and specificity of 57%. Maximum P-wave duration as measured from standard electrocardiogram did not differentiate patients who did or did not develop AF. Patients who developed AF had a higher incidence of postoperative pneumonia (14 vs. 4%;P = 0.001), acute respiratory failure (8 vs. 1.6%;P = 0.01), greater hospital stay (17 +/- 17 vs. 10 +/- 9 days;P = 0.001) and 30-day mortality (11 vs. 3%;P = 0.001) when compared with those who did not develop AF, respectively.     

Atrioventricular block in coronary artery bypass surgery: perioperative predictors and impact on mortality

Introduction

Disturbances of the cardiac conduction system are frequent in the postoperative period of coronary artery bypass surgery. They are mostly reversible and associated with some injury of the conduction tissue, caused by the ischemic heart disease itself or by perioperative factors.

Objective

Primary: investigate the association between perioperative factors and the emergence of atrioventricular block in the postoperative period of coronary artery bypass surgery. Secondary: determine the need for temporary pacing and of a permanent pacemaker in the postoperative period of coronary artery bypass surgery and the impact on hospital stay and hospital mortality.

Methods

Analysis of a retrospective cohort of patients submitted to coronary artery bypass surgery from the database of the Postoperative Heart Surgery Unit of the Sao Lucas Hospital of the Pontifical Catholic University of Rio Grande do Sul, using the logistic regression method.

Results

In the period from January 1996 to December 2012, 3532 coronary artery bypass surgery were carried out. Two hundred and eighty-eight (8.15% of the total sample) patients had atrioventricular block during the postoperative period of coronary artery bypass surgery, requiring temporary pacing. Eight of those who had atrioventricular block progressed to implantation of a permanent pacemaker (0.23% of the total sample). Multivariate analysis revealed a significant association of atrioventricular block with age above 60 years (OR=2.34; CI 95% 1.75-3.12; P<0.0001), female gender (OR=1.37; CI 95% 1.06-1.77; P=0.015), chronic kidney disease (OR=2.05; CI 95% 1.49-2.81; P<0.0001), atrial fibrillation (OR=2.06; CI 95% 1.16-3.66; P=0.014), functional class III and IV of the New York Heart Association (OR=1.43; CI 95% 1.03-1.98; P=0.031), perioperative acute myocardial infarction (OR=1.70; CI 95% 1.26-2.29; P<0.0001) and with the use of the intra-aortic balloon in the postoperative period of coronary artery bypass surgery (OR=1.92; CI 95% 1.21-3.05; P=0.006). The presence of atrioventricular block resulted in a significant increase in mortality (17.9% vs. 7.3% in those who did not develop atrioventricular block) (OR=2.09; CI 95% 1.46-2.99; P<0.0001) and a longer hospital stay (12.75 days x 10.53 days for those who didn''t develop atrioventricular block) (OR=1.01; CI 95% 1.00-1.02; P=0.01).

Conclusions

In most cases, atrioventricular block in the postoperative period of coronary artery bypass surgery is transient and associated with several perioperative factors: age above 60 years, female sex, chronic kidney disease, atrial fibrillation, New York Heart Association functional class III or IV, perioperative acute myocardial infarction and use of an intra-aortic balloon. Its occurrence prolongs hospitalization and, above all, doubles the risk of mortality.     

Multivariate analysis of predictors of late stroke after total aortic arch repair.

OBJECTIVE: The number of aortic surgeries has recently increased, with improvement of outcome due to the development of various novel operative techniques and adjuncts. Although the postoperative incidence of stroke, the most severe complication of aortic surgery, is still a matter of concern and has been described well previously, late stroke after aortic arch repair has not been described well. We assessed the incidence and predictors of late stroke after total aortic arch repair. METHODS: From January 1993 to December 2003, 470 patients underwent total aortic arch repair in our institution. All patients, whether undergoing elective, urgent, or emergent aortic arch repair, were included. Emergent operation was required for 115 patients because of rupture or acute type A dissection. For brain protection, retrograde cerebral perfusion was used in 27% (125) and selective cerebral perfusion in 75% (353) of cases. The follow-up period was 32.5+/-31.5 months. Late stroke was defined as stroke occurring more than 30 days postoperatively. RESULTS: The incidence of early postoperative stroke was 4.9% (23/470), while that of late postoperative stroke was 6.0% (28/470). On univariate analysis, postoperative atrial fibrillation (P=0.014), preoperative prevalence of craniocervical lesions (P=0.0001), and advanced age (P=0.046) were each significantly related to late stroke. A Cox proportional hazards model detected postoperative atrial fibrillation (P=0.013, OR=3.02, 95% CI: 1.26-7.24) and preoperative prevalence of craniocervical lesions (P=0.0001, OR=5.37, 95% CI: 2.30-12.52) as predictors of late stroke. CONCLUSIONS: Postoperative atrial fibrillation and preoperative prevalence of craniocervical lesions were found to be risk factors for late stroke after total aortic arch repair.     

Coronary revascularization of the circumflex system: different approaches and long-term outcome

BACKGROUND: Minimally invasive direct coronary artery bypass, without cardiopulmonary bypass, through a left lateral thoracotomy approach (lateral MIDCAB), is a safe alternative to coronary artery bypass surgery using cardiopulmonary bypass (on-pump CABG) of the circumflex system via median sternotomy. However, it is unknown whether lateral MIDCAB may yield an improved long-term outcome over the conventional on-pump median sternotomy approach. METHODS: We compared the perioperative outcomes of patients undergoing lateral MIDCAB (n = 34) versus conventional on-pump CABG of the circumflex system (n = 16) from June 1996 to July 1999. The two groups were similar with respect to baseline characteristics and risk stratification. Patients who required only one or two grafts for complete revascularization were included. RESULTS: Lateral MIDCAB patients had a lower need than on-pump CABG patients for intraoperative (12% MIDCAB vs 43% on-pump CABG, p = 0.03) and postoperative transfusions (29% vs 69%, p = 0.01), had fewer neuropsychologic changes (0% vs 19%, p = 0.03), and had a lower rate of postoperative atrial fibrillation (12% vs 44%, p = 0.02). Lateral MIDCAB was also associated with a significantly lower postoperative length of stay (5 +/- 2 vs 7 +/- 3 days, p = 0.02). Actuarial survival at a mean period of follow-up of 19 +/- 11 months was 97% for the lateral MIDCAB versus 88% for the on-pump CABG group (p = 0.6). Event-free survival was 88% for lateral MIDCAB versus 81% for on-pump CABG (p = 0.1). CONCLUSIONS: Lateral MIDCAB may safely be performed in patients with isolated coronary artery disease of the circumflex system with improved early morbidity and an abbreviated hospital stay compared with conventional median sternotomy on-pump CABG.     

Determinants of stroke after coronary artery bypass grafting.

OBJECTIVES: Cerebrovascular accidents (CVA) after CABG are deleterious complications whose prevention remains poorly defined. The aim of this study was to identify the determinants for CVA after CABG. METHODS: Nine thousand nine hundred and sixteen patients underwent CABG at our institution from January 1992 to June 2002. Data were prospectively collected and univariate/multivariate analyses conducted. RESULTS: Two hundred and eight patients (2.1%) suffered perioperative CVA. Univariate analysis showed a higher risk profile in the CVA group including advanced age, depressed percent left ventricular ejection fraction (LVEF), unstable angina, diabetes mellitus (DM), chronic renal failure (CRF), redo surgery, peripheral vascular disease (PVD), previous CVA, and higher Parsonnet score (P<0.001). Furthermore, the CVA group had longer myocardial ischemia (CVA 56.2 +/-40.9 vs. Control 50.4+/-20.9 min, P=0.03) and cardiopulmonary bypass (CPB) times (CVA 87.4+/-30.0 min vs. Control 78.9 +/-25.9 min, P<0.0001), and lower off-pump surgery rate (CVA 1.4% vs. Control 4.7%, P=0.01). Multivariable analysis identified seven preoperative and two perioperative determinants for CVA: LVEF<30% (odds ratio (OR)=2.49), previous CVA (OR=2.15), DM (OR=1.78), redo (OR=1.76), PVD (OR=1.66), CRF (OR=1.55), age (OR=1.03), perioperative intra-aortic balloon pump (OR=1.83), and transfusion rate (OR=1.59). Perioperative mortality was higher in the CVA group (CVA 18.6% vs. Control 2.6%, P<0.0001). CONCLUSIONS: Although occurrence of CVA seems mainly related to preoperative comorbidities, perioperative surgical variables, such as off-pump surgery, myocardial ischemia and cardiopulmonary bypass time, do not seem to independently influence CVA rate after CABG. In this regard CVA prevention should be performed before posing an indication to CABG, and closer evaluation of patients' risk profiles and tailored clinical/surgical strategies for those patients at higher risk for CVA occurrence should be included.