Predictors Of Postoperative Atrial Fibrillation Research Articles

Obstructive Sleep Apnea Is an Independent Predictor of Postoperative Atrial Fibrillation in Cardiac Surgery

To test the hypothesis that obstructive sleep apnea (OSA) is a risk factor for development of postoperative atrial fibrillation (POAF) after cardiac surgery. Retrospective analysis. Single-center university hospital. Five hundred forty-five patients in sinus rhythm preoperatively undergoing coronary artery bypass grafting (CABG), aortic valve replacement, mitral valve replacement/repair, or combined valve/CABG surgery from January 2008 to April 2011. Retrospective review of medical records. Postoperative atrial fibrillation was defined as atrial fibrillation requiring therapeutic intervention. Of 545 cardiac surgical patients, 226 (41%) patients developed POAF. The risk was higher in 72 OSA patients than 473 patients without OSA (67% v 38%, adjusted hazard ratio 1.83 [95% CI: 1.30-2.58], p<0.001). Of the 32 OSA patients who used home positive airway pressure (PAP) therapy, 18 (56%) developed POAF compared with 29 of 38 (76%) patients who did not use PAP at home (unadjusted hazard ratio 0.63 [95% CI: 0.35-1.15], p = 0.13). OSA is significantly associated with POAF in cardiac surgery patients. Further investigation is needed to determine whether or not use of positive airway pressure in OSA patients reduces the risk of POAF.

Renal dysfunction and the risk of postoperative atrial fibrillation after cardiac surgery: role beyond the CHA2DS2-VASc score.

To investigate whether renal dysfunction is a useful predictor of postoperative atrial fibrillation (POAF) after cardiac surgery. We also aimed to determine whether the addition of renal dysfunction into the scoring system could improve diagnostic accuracy of the CHA2DS2-VASc score to predict POAF. The study prospectively enrolled 350 consecutive patients who underwent cardiac surgery. Echocardiography was performed before cardiac surgery. Renal dysfunction was defined as estimated glomerular filtration rate < 60 mL min(-1) 1.73 m(-2). All patients were monitored with continuous electrocardiographic telemetry for the occurrence of POAF until the day of hospital dismissal. Postoperative atrial fibrillation occurred in 103 of 350 patients (29%). Patients with POAF was associated with longer intensive care unit stay compared with those without POAF (3.7 ± 2.2 vs. 3.1 ± 1.4 days, P = 0.002). Both the CHA2DS2-VASc score and renal dysfunction were independent predictors of POAF in multivariate analysis. Renal dysfunction can further stratify patients with a CHA2DS2-VASc score of 0 or 1 into two groups with different POAF rates (3.1% vs. 68.8%, P < 0.001). A new scoring system (R-CHA2DS2-VASc score) derived by assigning an additional point representing renal dysfunction to the CHA2DS2-VASc score could improve its predictive accuracy. The area under the receiver operating characteristic curve increased from 0.68 to 0.71 (P < 0.001). Furthermore, the rate of left ventricular diastolic dysfunction also increased with increasing renal dysfunction. Renal dysfunction, associated with left ventricular diastolic dysfunction, was a significant risk factor for POAF after cardiac surgery and may improve the diagnostic accuracy of the CHA2DS2-VASc score.

Preoperative hypothyroidism is a risk factor for postoperative atrial fibrillation in cardiac surgical patients.

Although studies analyzing the effect of thyroid supplementation on postoperative morbidity and mortality from cardiac surgery have been inconclusive, they suggest a role in the prevention of postoperative atrial fibrillation. To further explore this relationship we conducted a retrospective study to determine whether abnormalities in routine preoperative thyroid function studies correlate with the incidence of postoperative atrial fibrillation. From May 2004 until July 2011, 821 patients with complete thyroid function testing performed preoperatively underwent cardiac surgery. Preoperative, intraoperative, and postoperative laboratory, clinical and hemodynamic data including postoperative electrocardiogram monitoring were retrospectively evaluated. Mean age was 65.7 years and 36% (294) of patients were female. Mean preoperative ejection fraction was 48.6% and 18% (100) had clinical heart failure. Ninety percent (682) of patients were euthyroid and 10% (77) were hypothyroid. Atrial fibrillation occurred significantly more frequently in hypothyroid patients (33.4% vs. 22.5%; p = .033). In multivariable analysis, increasing thyroid stimulating hormone (TSH) level (OR: 1.11; CI: 1.01 to 1.22; p = .030) was an independent predictor of postoperative atrial fibrillation. Beta blocker use within 24 hours prior to operation was protective (OR: .54; CI: .35 to .83; p = .005). Length of stay was significantly longer in patients with postoperative atrial fibrillation (9.1 vs. 6.5 days; p < .001). In the current study, preoperative hypothyroidism was associated with postoperative atrial fibrillation. Further studies are warranted to delineate whether preoperative hypothyroidism is a useful biomarker for selecting patients most likely to benefit from preoperative thyroid supplementation in the prevention of postoperative atrial fibrillation.

Low Circulating Levels of Growth Differentiation Factor-15 Before Coronary Artery Bypass Surgery May Predict Postoperative Atrial Fibrillation.

To assess the role of growth differentiation factor-15 (GDF-15) as a potential new predictor of postoperative atrial fibrillation (POAF) after off-pump (OFP) and on-pump (ONP) coronary artery bypass graft (CABG) surgery. Prospective, single-center, observational study. University teaching hospital. The first 50 patients planned for OFP surgery and the first 50 patients planned for ONP surgery among patients referred for CABG with the following exclusion criteria: age<18 or>80 years, previous atrial fibrillation/flutter, previous treatment with amiodarone, previous cardiac surgery, and emergency surgery. Included patients were equipped with long-duration (7 days) Holter-ECG monitoring. POAF was defined as an AF episode lasting>30 seconds. All patients underwent preoperative echocardiography to assess left ventricular ejection fraction and left atrial diameter. GDF-15 levels were assessed after induction of anesthesia and 12 hours after arrival at the intensive care unit. Among the 100 patients, 34 (34%) developed POAF. In Cox multivariate regression analysis, the EuroSCORE, left atrial diameter>45 mm, and low GDF-15 levels at induction were associated independently with the onset of POAF. In contrast, preoperative NT-proBNP levels did not predict POAF. The use of ONP surgery was not associated with a higher incidence of POAF, even though baseline and follow-up characteristics in ONP and OFP patients were identical. In patients with no history of AF, a low plasma level of GDF-15 before CABG surgery was a strong independent predictor of POAF. Moreover, preoperative plasma GDF-15 levels added an incremental predictive value to classic risk factors of POAF.

Abstract 302: Echocardiographic Parameters in Perioperative Atrial Fibrillation in Cardiac and Non-Cardiac Surgery Patients

Background: We hypothesized that patients with new onset atrial fibrillation (AFib) following cardiac or non-cardiac surgery have similar echocardiographic features, regardless of the type of surgery. Methods: Study cohort included 4562 consecutive patients without history of atrial fibrillation undergoing general, thoracic or cardiovascular surgeries at a single tertiary academic medical center. Retrospective chart and echocardiogram review was performed. Chi-square, logistic regression, and analysis of variance were performed. Long-term all cause mortality was determined through Social Security Death Index. The study was approved by the institutional IRB. Results: Post-operative AFib was noted in 24% (275/1141) after cardiac surgery, 1.2 % (10/804) after thoracic non-cardiac surgery, and 0.7% (18/2617) after general non-cardiac non-thoracic surgery (p&lt;0.0001). On available echocardiograms, 18% (48/264) had LV dilatation and 38% (98/261) had moderate or severe LV dysfunction. The left atrium was dilated in 53% (139/260). Moderate or severe tricuspid regurgitation was noted in 11% (15/128), mitral regurgitation in 28% (45/16), mitral stenosis in 13% (11/82), aortic insufficiency in 27% (37/135), and aortic stenosis in 63% (19/135). When adjusted for the presence of coronary artery disease, valvular disease, age, and gender, only aortic valve stenosis remained an important independent predictor of post-operative atrial fibrillation in non-cardiac surgery patients, HR=13.9 (95%CI 1.5-132.3, p&lt;0.022). Conclusion: Despite significantly increased prevalence of new onset AFib after cardiac surgery, pre-existing cardiovascular conditions, specifically aortic valve stenosis, confer an increased risk of post-operative atrial fibrillation rather than the procedure itself. Improved resource utilization can be expected if post-operative ECG monitoring is limited to the high risk patients, identifiable during peri-operative screening. Prospective studies of this important subject are needed.

Transoesophageal echocardiography for prediction of postoperative atrial fibrillation after isolated aortic valve replacement: two-dimensional speckle tracking for intraoperative assessment of left ventricular longitudinal strain.

Recent studies suggested association between impaired left ventricular long-axis function and arrhythmic events early after open heart surgery. This prospective study investigated the predictive value of a depressed intraoperative global longitudinal strain (GLS) for postoperative atrial fibrillation after isolated aortic valve replacement in patients with preserved ejection fraction. A total of 107 patients with ejection fraction ≥50% and moderate-to-severe aortic stenosis undergoing isolated aortic valve replacement were enrolled. All patients underwent intraoperative transoesophageal echocardiography before surgical incision (T1) and after closure of the sternotomy (T2) with semiautomated measurement of GLS, and were followed for the occurrence of postoperative atrial fibrillation during the hospitalization. The incidence of postoperative atrial fibrillation was 37/107 (34.6%). Patients with postoperative atrial fibrillation were associated with increased length of hospitalization and a higher risk of low cardiac output syndrome and pulmonary complications. On univariate analysis, significant risk factors associated with postoperative atrial fibrillation were E/e' ratio, left atrial volume index (LAVi), GLST2 and ΔGLS%. On multivariable analysis, GLST2 (odds ratio: 1.21; 95% confidence interval (CI): 1.06-1.56, P = 0.031) and ΔGLS% (odds ratio: 3.66; 95% CI: 1.85-6.79, P = 0.001) were independent predictors of postoperative atrial fibrillation. The best cut-off values for the prediction were GLST2 >-12.75% and ΔGLS% >19.50%, the latter of which had incremental predictive value for postoperative atrial fibrillation. A significant reduction of intraoperative GLS provides independent information for predicting postoperative atrial fibrillation in patients undergoing aortic valve replacement, and may help to identify patients who are most likely to benefit from targeted prophylaxis.

Premature atrial contraction as a predictor of postoperative atrial fibrillation.

Postoperative atrial fibrillation occurs in 20%-60% of patients after cardiac surgery. Recently, premature atrial contraction has been considered an initiator of atrial fibrillation. This study evaluated whether the frequency of premature atrial contractions predicts the occurrence of postoperative atrial fibrillation. The subjects of this study were 70 patients with no history of atrial fibrillation who had undergone a 24-h Holter electrocardiogram before off-pump coronary artery bypass. Their records were reviewed and postoperative electrocardiograms and telemetry strips were analyzed for postoperative atrial fibrillation. Postoperative atrial fibrillation was documented in 22 (31.4%) patients. The frequency of preoperative premature atrial contractions was significantly higher in the postoperative atrial fibrillation group (4128 ± 7186 vs. 69 ± 221 beats/24 h, p < 0.001). The incidence of postoperative atrial fibrillation increased with the frequency of preoperative premature atrial contractions which occurred in 60% of patients in the upper 50th percentile group of preoperative premature atrial contractions. Multivariate logistic regression analysis revealed the upper 50th percentile group of preoperative premature atrial contractions (odds ratio = 67; 95% confidence interval: 5.51-838; p = 0.001) to be an independent predictor of postoperative atrial fibrillation. A high frequency of preoperative premature atrial contractions is a strong independent predictor of postoperative atrial fibrillation in off-pump coronary artery bypass.

LEFT ATRIAL EMPTYING FRACTION AS A PREDICTOR OF POSTOPERATIVE ATRIAL FIBRILLATION IN PATIENTS UNDERGOING MINIMALLY INVASIVE VALVE SURGERY

Increased left atrial volumes have been associated with a higher incidence of post-operative atrial fibrillation (POAF). We investigated whether left atrial emptying fraction (LAEF) is predictor of POAF. We screened 689 patients undergoing minimally invasive valve surgery between September 2010 and

A prospective randomized controlled trial on the incidence and predictors of late-phase postoperative atrial fibrillation up to 30 days and the preventive value of biatrial pacing

Postoperative atrial fibrillation (POAF) is considered to be a transient arrhythmia in the first week after cardiac surgery. To determine the 30-day incidence and predictors of POAF and the value of postoperative overdrive biatrial pacing in the prevention of POAF. Patients (n = 148) without a history of atrial fibrillation undergoing aortic valve replacement or coronary artery bypass graft (CABG) were randomized into a pacing group (n = 75) and a control group. Patients were treated with standardized sotalol postoperatively. Rhythm was continuously monitored for 30 days by a transtelephonic event recorder. POAF occurred in 73 (49.3%) patients, of whom 60 (40.5%) patients showed POAF during postoperative days (PODs) 0-5 and 37 (25%) patients during PODs 6-30. Prolonged aortic cross-clamp time was an important univariate predictor of 30-day and of late POAF (PODs 6-30; P = .017 and P = .03, respectively). Best-fit model analysis using 15 predetermined risk factors for POAF showed different positive interactive effects for early POAF (ie, baseline C-reactive protein levels with a history of myocardial infarction or low body mass index) and late POAF (ie, high body mass index, diabetes mellitus, baseline C-reactive protein, early POAF, creatinine levels, type of operation, smoking, and male gender). Biatrial pacing reduced the late POAF incidence in patients with aortic cross-clamp time >50 minutes (P = .006). POAF is not limited to the first week after cardiac surgery but also occurs frequently in the postoperative month. It is desirable to regularly follow patients with POAF for atrial fibrillation recurrences after discharge.

OP-231 Preoperative Left Ventricular Global Strain Predicts Postoperative Atrial Fibrillation in Patients Undergoing Coronary By-Pass Surgery

The American Journal of Cardiology MARCH 13e16, 2014 10 IN AND C -OP-231 Preoperative Left Ventricular Global Strain Predicts Postoperative Atrial Fibrillation in Patients Undergoing Coronary By-Pass Surgery. S. Topcu, K. Kalkan, Z. Lazo glu, O. Gulcu, U. Aksu, Z. Avsar, E. Aksakal. Cardiology Department, Ataturk University, Erzurum, Turkey; Department of Medical Education, Ataturk University, Erzurum, Turkey. Introduction: Preoperative left ventricular dysfunction is closely related to postoperative atrial fibrillation (POAF). Left ventricular global strain (LVGS) is more sensitive measurement of left ventricular dysfunction than conventional measurements. However, there is no studywhether left ventricular global strain assessed by speckle tracking echocardiography predicts postoperative atrial fibrillation and in patients undergoing coronary artery by-pass surgery (CABG). Methods: Fifty-one patients with sinus rhythm who undergoing to CABG were enrolled. Preoperative left ventricular four chamber, two chamber and apical long axis longitudinal strain were measured. Left ventricular global strain obtained as average of left ventricular four chamber, two chamber and apical long axis longitudinal strain. POAF was defined as documentation of AF with at least 5 min duration in 96 hours at postoperative period. Results: Postoperative atrial fibrillation occurred 19 of 51 patients (37%). The mean duration of AF was 13.1 8.2 hours and POAF was observed 2.8 1.2 days after the CABG. Patients with POAF had older, larger Left atrial volume, lower left ventricular ejection fraction and left ventricular global strain and higher syntax score. Multiple logistic regression analysis revealed only LVGS (OR:0.92, 95% CI 0.88-0.96, p1⁄40.001) was independent predictor of POAF. The ROC curve analysis revealed that AUC for LVGS in prediction of POAF was 0.787 (0.6800.894). Cut-off value of 12.1 for LVGS had 76% sensitivity and 82% specificity. Conclusion: Pre-operative left ventricular global strain wasindependently predict the postoperative atrial fibrillation in patients undergoing CABG.

Predictors of Postoperative Atrial Fibrillation after On-Pump Coronary Artery Bypass Grafting: Is Duration of Mechanical Ventilation Time a Risk Factor?

This study aimed to establish the role of risk factors in the etiology of postoperative atrial fibrillation (AF) after coronary artery bypass grafting (CABG). Between September 2001 and March 2008, 1040 patients underwent isolated CABG at our clinic. Nine hundred and eleven of these patients did not have any AF(Non-AF Group) and the other one hundred and twenty-nine had AF (AF Group). A retrospective study was performed for patient, disease and treatment related factors and multivariate analysis was used to identify independent clinical predictors of postoperative AF. Postoperative AF was identified in 129 (12.4%) of the patients, and those were significantly older and had significantly higher additive EuroSCORE score as compared with patients without AF. During the postoperative course, patients with postoperative AF also had significantly higher and prolonged (≥6 hours) mechanical ventilation time, longer and prolonged intensive care unit stay and longer hospital stay. Logistic regression analysis revealed that postoperative AF development ratio was 1.690 times higher when the ventilation time was over 6 hours (OR 1.690, 95% CI 1.092-2.615, p = 0.018); 1.240 times higher in the presence of elevated additive EuroSCORE score (OR 1.240, 95% CI1.109-1.385, p = 0.0001); 1.052 times higher in the presence of advanced age (OR 1.052,95% CI 1.031-1.0741, p = 0.0001). Analysis of our data reveals that, patient's age, additive EuroSCORE score, and prolonged ventilation are predictors of postoperative AF. Identification of risk factors might lead to better prevention of this problem and its potential consequences. However, to support our investigation and obtain more reliable evidence, prospective randomized controlled trials are needed.

Incidence and Predictors of Postoperative Atrial Fibrillation in Kidney Transplant Recipients

Postoperative atrial fibrillation (POAF) is a complication of cardiothoracic and noncardiothoracic surgery. Kidney transplant recipients bear several known risk factors and may have a higher incidence of POAF. We retrospectively studied kidney and kidney/liver transplant recipients to estimate their POAF incidence and identify relevant risk factors. We also adapted a clinical score originally designed to predict thromboembolic risk in atrial fibrillation (AF; CHA2DS2-VASc) for assessing transplant patients. We reviewed the clinical charts of kidney or kidney/liver transplant recipients from January 2005 to December 2008 at St. Orsola University Hospital Kidney Transplant Centre. Patients with and without POAF were compared on a number of clinical, laboratory, and instrumental data. The POAF incidence in kidney transplant recipients was 8.2%. Risk factors for POAF identified in univariate analyses included older recipient age, history of myocardial infarction, history of AF, liver/kidney transplantation, arterial stiffness, atherosclerotic plaques in the aorta or lower limbs, and diabetes mellitus. In a multivariate analysis, age, myocardial infarction history and combined liver/kidney transplantation were significant independent predictors of POAF. The modified CHA2DS2-VASc score proved to have a better predictive validity that the original CHA2DS2-VASc (area under the curve=0.71, 95% confidence interval=0.63-0.79 vs. area under the curve=0.62, 95% confidence interval=0.52-0.73, respectively). AF is a notable complication of kidney, and particularly simultaneous liver/kidney, transplant surgery. Age, previous myocardial infarction, and simultaneous liver/kidney transplant independently predicted POAF. The modified CHA2DS2-VASc score could be useful to predict POAF risk in kidney transplant candidates.

Abstract 9908: Transcatheter Aortic Valve Replacement for High-risk Severe Aortic Stenosis: An Analysis of Incidence, Predictors and Prognostic Impact of New-onset Postprocedural Atrial Fibrillation- Mayo Clinic Experience

Introduction: Atrial fibrillation (AF) is a serious complication, which occurs in 30% to 40% of patients after surgical aortic valve replacement (SAVR) and contributes to adverse outcomes. Advanced technology has enabled transcatheter aortic valve replacement (TAVR) in patients with High-risk Severe Aortic Stenosis (HRSAS). In these patients, the compliance of the systemic vasculature is an independent predictor of diastolic dysfunction, a known predictor of postoperative AF (POAF). We hypothesize that patients with HRSAS undergoing TAVR represent a population at increased risk for POAF. METHODS: The medical records of 195 TAVR patients at the Mayo Clinic from November 2008 to January 2013 were analyzed. All patient demographic, clinical, pre- and post-procedural outcomes were collected from the patients’ medical records, and reviewed to ascertain all cases of POAF (AF ≤30 days of surgery). Patients with a prior history of AF (n= 75 (38.5%)) were excluded. Logistic regression analysis was used to identify clinical predictors of POAF after TAVR. Results: The mean age of the study population was 80.8±7.8 years and 60.8% (n=73) were men. The mean STS risk score was 8.9±5.1. Of the 120 patients without prior AF, 20.8% (n=25) developed new-onset POAF after TAVR. Patients who developed POAF were more likely to have undergone a transapical or transaortic TAVR approach (OR 3.20; 95% CI (1.3-8.0), had a higher incidence of renal complications (52.0% vs 21.5%; p= 0.003), greater hospital length of stay (7.4±2.58 vs 5.0±2.6 days; p= 0.0003, and a trend toward higher 30-day mortality (28.0% vs 13.7%; p= 0.09) and pulmonary complications (16.0% vs 5.4%; p= 0.08) compared with those who did not develop POAF, respectively. Neurologic complications were not different between the 2 group (4.0% vs 3.2%; p= 0.85). Conclusions: Patients with High-risk Severe Aortic Stenosis undergoing TAVR have increased risk of POAF, primarily associated with a transapical or aortic surgical approach. Patients who develop POAF had higher incidence of post-procedural complications and longer hospitalizations. Therefore, perioperative strategies aimed at prevention of POAF are as important in TAVR patients as in those undergoing SAVR.

Clinical and echocardiographic predicators of postoperative atrial fibrillation.

Postoperative atrial fibrillation is the most common arrhythmiaafter coronary artery bypass grafting,with a reported incidence of 10% to 60%. Preoperative clinical and echocardiographic data, especially the atrial electromechanical interval, predict postoperative atrial fibrillation in elective coronary artery bypass patients. A prospective study evaluated preoperative clinical and echocardiographic data in 192 patients who underwent elective coronary artery bypass from 2010 to 2012. 18 (9.37%) patients developed postoperative atrial fibrillation. Compared to patients without postoperative atrial fibrillation, these 18 had significantly longer intensive care unit and hospital stays, they were significantly older (58.62 ± 10.02 vs. 53.22 ± 8.23 years; p = 0.02), with a larger left atrial volume (83.39 ± 8.31 vs. 55.47 ± 8.37 cm(3), p = 0.001), longer atrial electromechanical interval (133.67 ± 8.15 vs. 98.05 ± 6.71 ms p < 0.0001), and lower tissue Doppler imaging systolic velocity wave amplitude (6.6 ± 1 vs. 9.4 ± 2.2 cm·s(-1); p = 0.001); they also had a higher prevalence of hypertension (61.11% vs. 38.5%; p = 0.04). Using 115 ms as the cutoff value of atrial electromechanical interval enabled us to detect patients who developed postoperative atrial fibrillation with 100% sensitivity, 77% specificity, 78% positive predictive value, and 100% negative predictive value. Older hypertensive patients are at higher risk of developing postoperative atrial fibrillation. Preoperative measurement of atrial electromechanical interval by tissue Doppler echocardiography is a useful predictor of postoperative atrial fibrillation in coronary artery bypass patients.

Predictors of Postoperative Atrial Fibrillation in Patients With Coronary Artery Disease Undergoing Cardiopulmonary Bypass: A Possible Role for Myocardial Ischemia and Atrial Inflammation

To evaluate the preoperative presence of C-reactive protein (CRP) and troponin T(hs-TnT) in patients with coronary artery disease (CAD) undergoing cardiopulmonary bypass (CPB) in order to better clarify the role of atrial inflammation and/or myocardial ischemia in the development of postoperative atrial fibrillation (POAF). Prospective, nonrandomized study. University hospital. Thirty-eight consecutive ischemic patients admitted to the authors' hospital for CAD undergoing elective on-pump coronary artery bypass grafting (CABG). Elective on-pump CABG. Peripheral blood samples were collected from all patients before and 24 hours after CABG to assess high sensitive (hs)-CRP and troponin T (hs-TnT) levels. The patients' heart rhythm was monitored by continuous ECG telemetry. Biopsies from the right atrial appendage were obtained at the beginning of the CABG procedure in order to perform immunohistochemistry for CRP and reverse transcription polymerase chain reaction for CRP mRNA expression. Fourteen patients out of 38 (36%) developed POAF. Atrial CRP was found in 31 patients (82%), 10 with POAF and 21 with sinus rhythm (71% v 87% respectively, p = ns). None of the atrial samples was positive for CRP mRNA. Atrial CRP did not correlate with serum hs-CRP levels and with occurrence of POAF, but with the incidence of diabetes (p = 0.010). Postoperative hs-TnT levels, but not hs-CRP levels, were identified as the only predictor of POAF occurrence (p = 0.016). In patients undergoing CABG, neither peripheral nor tissue preoperative CRP levels, but only postoperative hs-TnT levels, correlated with POAF, suggesting the primary role of an ischemic trigger of atrial fibrillation.

Clinical utility of CHADS2 and CHA2DS2-VASc scoring systems for predicting postoperative atrial fibrillation after cardiac surgery

The presence of postoperative atrial fibrillation predicts a higher short- and long-term mortality rates; however, no scoring system has been used to discriminate patients at high risk for this complication. The aim of this study was to investigate whether the CHADS2 and CHA2DS2-VASc scores are useful risk assessment tools for new-onset atrial fibrillation after cardiac surgery. A total of 277 consecutive patients who underwent cardiac surgery were prospectively included in this risk stratification study. We calculated the CHADS2 and CHA2DS2-VASc scores from the data collected. The primary end point was the development of postoperative atrial fibrillation within 30days after cardiac surgery. Eighty-four (30%) of the patients had postoperative atrial fibrillation at a median of 2days (range, 0-27days) after cardiac surgery. The CHADS2 and CHA2DS2-VASc scores were significant predictors of postoperative atrial fibrillation in separate multivariate regression analyses. The Kaplan-Meier analysis obtained a higher postoperative atrial fibrillation rate when based on the CHADS2 and CHA2DS2-VASc scores of at least 2 than when based on scores less than 2 (both log rank, P<.001). In addition, the CHA2DS2-VASc scores could be used to further stratify the patients with CHADS2 scores of 0 or 1 into 2 groups with different postoperative atrial fibrillation rates at a cutoff value of 2 (12% vs 32%; P=.01). CHADS2 and CHA2DS2-VASc scores were predictive of postoperative atrial fibrillation after cardiac surgery and may be helpful for identifying high-risk patients.

Preoperative left atrial volume index predicts postoperative atrial fibrillation in patients with severe aortic valve stenosis

Left atrial enlargement correlates with the severity of diastolic dysfunction and is a predictor of cardiovascular complications such as atrial fibrillation. Aortic valve stenosis (AS) causes left atrial enlargement and progression of diastolic dysfunction. The aim of this study was to investigate the efficacy of the preoperative left atrial volume index (LAVI) in predicting postoperative outcome in patients with severe AS. Forty-seven patients with severe AS who underwent aortic valve replacement were examined. Transthoracic echocardiography and LAVI measurement were performed on admission. Patients were divided into two groups according to optimal cut-off values of LAVI derived from receiver operating characteristic curves for postoperative atrial fibrillation (POAF) (group S: LAVI <52 ml/m(2), group L: LAVI ≥52 ml/m(2)). The incidence of POAF, ventilation time, inotropic support time, duration of stay in intensive care, and overall duration of hospital stay were evaluated. By univariate analysis, the incidence of POAF in group S was significantly lower than that in group L (25.9 and 65.0%, respectively; P < 0.01). Values for other parameters were higher in group L, although the differences were insignificant. In patients with severe AS, a preoperative LAVI of ≥52 ml/m(2) may be a useful predictor of POAF, although the efficacy of this index for predicting other postoperative outcomes has yet to be determined.

Usefulness of the mean platelet volume for predicting new-onset atrial fibrillation after isolated coronary artery bypass grafting

Postoperative atrial fibrillation (AF) is a common complication of coronary artery bypass grafting (CABG). The mean platelet volume (MPV) is an important marker of platelet activity and is associated with cardiovascular risk factors. We investigated whether the MPV is associated with the development of AF after CABG. This study included 208 patients undergoing elective isolated CABG. We evaluated the standard preoperative 12-lead electrocardiograph (ECG) recorded at a paper speed of 25 mm/s obtained for each patient from our hospital records before surgery. All study patients underwent standard CABG requiring cardiopulmonary bypass without concurrent valvular surgery. Forty-three patients were excluded. After CABG, all patients were monitored by telemetry and 12-lead ECGs. AF was defined using the established Society of Thoracic Surgeons definition. Postoperative AF occurred in 38 (22%) patients. The hemoglobin and platelet and leukocyte counts were similar in the groups with and without AF. However, the MPV and neutrophil/lymphocyte ratio were significantly higher in the AF group (8.9 [1.4] vs. 7.9 [1.2], p < 0.001 and 3.2 ± 1.9 vs. 2.6 ± 1.2, p = 0.005, respectively). In addition, the C-reactive protein (CRP) levels were significantly higher in the AF group (8.9 [19.6] vs. 5.3 [8.7], p = 0.025). Multivariate logistic regression analysis showed that MPV and CRP were independent predictors of postoperative AF (odds ratio [OR] 2.564, 95% confidence interval [CI] 1.326–4.958, p = 0.005; OR 1.055, 95% CI 1.000–1.114, p = 0.050, respectively). Our results show that increased platelet activity is associated with the development of AF after CABG.

Preoperative High N-Terminal pro-B-Type Natriuretic Peptide Level Can Predict the Incidence of Postoperative Atrial Fibrillation Following Off-Pump Coronary Artery Bypass Grafting

N-terminal pro-B type natriuretic peptide (NT-pro-BNP) is one of the biomarkers, increased by myocardial ischemia or subsequent, burdened wall stress. The aim of this study was to assess if NT-pro-BNP can predict the incidence of atrial fibrillation (AF) after off-pump coronary artery bypass grafting (OPCAB). NT-pro-BNP was measured preoperatively in 100 OPCAB patients without preoperative AF. Patients were divided into the AF group (n = 36) of those who developed postoperative AF, and the sinus rhythm (SR) group (n = 64), of those who did not. Odds ratio analysis was carried out with a logistic regression model using the threshold of the high quartile. Age was more advanced in group AF (70.8±8.7 years old) than in group SR(66.7±8.5 years old), P = 0.025. There were more emergencies in group AF (22.2%) than in group SR (10.9%), P = 0.15. Preoperative NT-pro-BNP was significantly higher in group AF (509.6±641.6 pg/mL) than in group SR (241.1±302.7 pg/mL), P = 0.006. Preoperative administration of statins was relatively greater in group SR (73.4%) than in group AF (58.3%), P = 0.18. Four factors withaPvalue below 0.2 in the univariate analysis were extracted, which were preoperative administration of statins, emergency, high NT-pro-BNP (>348 pg/mL, high quartile), and advanced age (>75 years old, high quartile). The constructed logistic regression model revealed that high NT-pro-BNP(>348 pg/mL, high quartile) was the only predictor of postoperative AF after OPCAB(P = 0.05; OR, 2.60; 95% CI, 0.96-7.05). A high preoperative level of NT-pro-BNP could predict the incidence of postoperative AF after OPCAB.

Contrasting effects of diabetes and metabolic syndrome on post-operative atrial fibrillation and in-hospital outcome after cardiac surgery

Metabolic syndrome (MS) is a cluster of metabolic perturbations reflecting insulin resistance, i.e. central obesity, hypertriglyceridemia, reduced HDL cholesterol, hypertension, and glucose intolerance [1]. MS is associated with a heightened risk of developing type 2 diabetes mellitus (DM) and cardiovascular disease. Several studies reported that MS significantly impacts clinical outcomes after cardiac surgery, and is an independent predictor of post-operative atrial fibrillation (POAF), the most common post-operative complication [2–5].