***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background —Atrial fibrillation ( AF ) is a frequently encountered arrhythmia after cardiac surgery , but its underlying mechanisms are still unclear . We hypothesize that autoimmune and inflammatory responses against heat shock protein 65 ( HSP65 ) may be involved and hence examined the relationship between HSP65 autoantibodies and occurrence of postoperative AF . Methods and Results —A prospect i ve study of 329 patients undergoing elective primary CABG was undertaken .  Cardiovascular risk factors , ECG characteristics , medications , and intraoperative and postoperative features were documented . Anti-HSP65 antibodies and C-reactive protein levels were measured in all preoperative blood sample s with ELISA .  Postoperative AF was defined as the characteristic arrhythmia , lasting for at least 15 minutes and confirmed on 12-lead ECG and occurring within the first postoperative week . This occurred in 62 patients ( 19 % ) . In univariate analysis , HSP65 antibodies were significantly higher in patients with postoperative AF ( P=0.02 ) . History of previous myocardial infa rct ion , duration of bypass , number of distal anastomosis , and duration of ventilation were also associated with AF ( P<0.05 ) , but C-reactive protein levels were not ( P=0.13 ) . Multivariate analysis confirmed the positive association of HSP65 antibodies with postoperative AF ( OR , 1.41 ; P=0.04 ) independent of age , sex , other cardiovascular risk factors , severity of coronary artery disease , duration of ventilation , duration of bypass , and left ventricular function . Conclusions —We report a novel association between anti-HSP65 antibodies and occurrence of postoperative AF , indicating a possible role for antibody-mediated immune response in its pathogenesis Objective : Atrial fibrillation ( AF ) is the most common arrhythmia following coronary artery by-pass graft surgery ( CABG ) . The value of SYNTAX score to predict postoperative atrial fibrillation ( PoAF ) has not been clearly addressed . We aim ed to evaluate this relationship in patients undergoing isolated CABG .  Methods : This study was design ed as a single-center , non-r and omized , observational , prospect i ve study . Ninety-four patients undergoing isolated on-pump CABG , who had sinus rhythm and were older than 18 years , were enrolled . Demographic characteristics of the patients were recorded ;  SYNTAX score  was calculated preoperatively for each patient . The univariate and multivariate logistic regression analysis were used to determine for predictors of PoAF . Results : The median SYNTAX score of the enrolled patients was 21 , ( 56–5 ) . PoAF was observed in 31 ( 33.3 % ) patients . Univariate logistic regression showed that age , chronic obstructive pulmonary disease ( COPD ) , red blood cell distribution width ( RDW ) , urea , initial troponin I , peak postoperative troponin I , interventricular septum , left atrial diameter , and SYNTAX score were significantly associated with the frequency of PoAF following CABG . An independent association was identified with age [ b 0.088 , p:0.023 , OR : 1.092 , 95 % CI ( 1.012–1.179 ) ] , COPD [ ( b : 2.222 , p:0.003 , OR : 9.228 , 95 % CI ( 2.150–39.602 ) ] , and SYNTAX score [ ( b : 0.130 , p:0.002 , OR : 1.139 , 95 % CI ( 1.050–1.235 ) ] . Conclusion : This study showed that a higher SYNTAX score was related to more frequent PoAF in patients undergoing isolated on-pump CABG Atrial fibrillation ( AF ) is the most common arrhythmia after cardiothoracic surgery . AF following coronary artery bypass graft ( CABG ) is associated with an increase in morbidity , mortality , hemodynamic instability , thromboembolic events , severity of heart failure and ICU and hospital stay . Corticosteroids have a variety of beneficial effects on recovery after elective surgery . This study was design ed to test the hypothesis that low dose of Methylprednisolone ( MP ) can affect post-CABG AF and early complications in patients with severe left ventricle dysfunction who underwent elective off-pump coronary artery bypass . A total of 120 patients with LV dysfunction undergoing elective off- pump CABG r and omly received either MP or placebo . Diabetic patients and those who were receiving corticosteroids were excluded . The MP group received 5mg/kg of MP intravenously after induction of anesthesia and the placebo group received an equal volume of normal saline . We evaluated Post-CABG variables including incidence , duration and frequency of AF recurrence and early morbidity such as bleeding , infection , vomiting , renal and respiratory dysfunctions , ICU or hospital stay and early mortality .  The mean age of patients was 62.11 ± 12.34 years with the 2.4 male to female ratio .  AF occurred in 23(19.2 % ) patients . No significant difference in the incidence of new AF was found between the placebo ( 21.7 % ) and MP group ( 16.7 % ) ( P=0.47 ) . MP did not affect postoperative bleeding , infection , vomiting , renal and respiratory dysfunction and mortality ; however , MP significantly reduced ICU and hospital length of stay . MP did not affect the incidence , duration and frequency of AF recurrence in patients with severe LV dysfunction undergoing off-pump CABG . However , MP could reduce ICU and hospital stay significantly in these patients OBJECTIVE To examine the relationship between proinflammatory cytokines , such as interleukin-6 ( IL-6 ) and C-reactive protein ( CRP ) and atrial fibrillation after  on-pump coronary artery bypass grafting ( CABG ) . METHODS Fifty-four patients with coronary artery disease undergoing elective CABG at the Maz and aran Medical University , Maz and aran , Iran were enrolled in our prospect i ve study in the year 2007 . Postoperatively , heart rate and rhythm were continuously monitored for 5 days . Fasting blood sample s were taken from all patients to examine quantities of  CRP and IL6  the day before surgery and on the second postoperative day in the intensive care unit . RESULTS From 54 patients , 11 patients ( 20.4 % ) developed atrial fibrillation ( AF ) after CABG . The median age of patients with AF was 51.45 + /- 10.74 compared with 57.28 + /- 9.04 for patients with sinus rhythm ( p=0.072 ) . Cardioplegic time , cross clamp time , and pump time were higher in the AF group , but there was no significant difference between the 2 groups . Preoperative CRP and IL6 levels were higher in patients with AF . The CRP and IL6 increased after CABG in all patients , but it increased more in the AF group . CONCLUSION There was a significant relationship between preoperative IL6 and AF in patients who underwent on-pump CABG  , but there was no relationship between CRP and AF . Therefore , administration of glucocorticoids , which significantly reduce plasma levels of IL6 can reduce the incidence of AF after on-pump CABG BACKGROUND Atrial fibrillation ( AF ) after coronary artery bypass grafting ( CABG ) is still the most common postoperative arrhythmic complication . Previous studies report that patients undergoing preoperative statin  therapy had a lower incidence of postoperative AF . This study aim ed to assess the effect of preoperative atorvastatin therapy on preventing AF following off-pump CABG in a r and omized , controlled trial . METHODS AND RESULTS The 140 consecutive patients undergoing elective off-pump CABG , without a history of AF or previous statin treatment , were enrolled and r and omly assigned to a statin ( atorvastatin 20 mg/day , n=71 ) or a control group ( placebo , n=69 ) starting 7 days preoperatively . The primary endpoint was the occurrence of postoperative AF ; secondary endpoints were major adverse in-hospital cardiac and cerebrovascular events and identification of variables predicting postoperative AF .  Atorvastatin significantly reduced the incidence of postoperative AF and the postoperative peak C-reactive protein ( CRP ) level vs placebo ( 14 % vs 34 % , P=0.009 ; 126.5 + /-22.3 vs 145.2 + /-31.6 mg/L , P<0.0001 ) . Logistic regression analysis showed preoperative atorvastatin treatment was an independent factor associated with a significant reduction in postoperative AF ( odds ratio ( OR ) 0.219 , P=0.005 ) , whereas a high postoperative CRP level was associated with increased risk ( OR 2.011 , P=0.013 ) . CONCLUSIONS Administration of atorvastatin 20 mg/day , initiated 1 week before elective off-pump CABG and continued in the postoperative period , significantly decreases postoperative AF OBJECTIVE 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 ) . DESIGN Prospect i ve , nonr and omized study . SETTING University hospital . PARTICIPANTS Thirty-eight consecutive ischemic patients admitted to the authors ' hospital for CAD undergoing elective on-pump coronary artery bypass grafting ( CABG ) .  INTERVENTION Elective on-pump CABG . MEASUREMENTS AND MAIN RESULTS Peripheral blood sample s 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 sample s 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 ) . CONCLUSIONS 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 BACKGROUND Atrial fibrillation is a common arrhythmia , after cardiac surgery . Reperfusion injury and inflammation associated with cardiac surgery are thought to be involved in its pathogenesis . We hypothesized that cytoprotective effects associated with heat shock protein 70 ( HSP70 ) could counteract these proarrhythmic insults . We therefore set out to examine the influence of heat shock protein 70 on the incidence of postoperative atrial fibrillation . METHODS We prospect ively recruited 80 patients undergoing elective coronary artery bypass surgery . Blood sample s were collected preoperatively . Right atrial tissue was obtained at surgery . Incidence of postoperative atrial fibrillation and its duration were noted . Using a nested case-control design , 15 patients who developed atrial fibrillation were matched for operative procedure , age , sex , and beta-blocker usage , with 15 controls from the remaining patients . Atrial heat shock protein 70 was subsequently quantified by immunohistochemistry . Serum heat shock protein was measured using enzyme-linked immunosorbent assay and high sensitivity C-reactive protein was determined by immunoturbidometric assay . RESULTS Intracellular HSP70 level was significantly higher in patients who did not develop atrial fibrillation ( 35 + /- 13 vs 19 + /- 15 ; p = 0.006 ) . Atrial HSP70 level negatively correlated with atrial fibrillation ; independent of other risk factors ( odds ratio = 0.90 ; 95 % confidence interval 0.84 to 0.99 , p = 0.02 ) . Serum HSP70 levels were similar in both groups ( p = 0.81 ) and did not correlate with intracellular levels ( p = 0.38 ) . Preoperative C-reactive protein levels were similar in both groups ( p = 0.93 ) . CONCLUSIONS Intracellular , but not serum , HSP70 level is negatively correlated with postoperative atrial fibrillation . This suggests a cardioprotective and an antiarrhythmic role for intracellular HSP70 The neutrophil/lymphocyte ( N/L ) ratio integrates information on the inflammatory milieu and physiologic stress . It 
    Output:
    
Pooled analysis showed baseline levels of CRP ( st and ard mean difference [ SMD ] 0.457 mg/L , p < 0.001 ) , baseline levels of IL-6 ( SMD 0.398 pg/mL , p < 0.001 ) , postoperative levels of CRP ( SMD 0.576 mg/L , p < 0.001 ) , postoperative levels of IL-6 ( SMD 1.66 pg/mL , p < 0.001 ) , postoperative levels of IL-8 ( SMD 0.839 pg/mL , p < 0.001 ) , and postoperative levels of IL-10 ( SMD 0.590 pg/mL , p < 0.001 ) to be relevant inflammatory parameters significantly associated with POAF .
Perioperative inflammation is proposed to be involved in the pathogenesis of POAF .
Therefore , perioperative assessment of CRP , IL-6 , IL-8 , and IL-10 can help clinicians in terms of predicting and monitoring for POAF