***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: AIMS The absolute white blood cell ( WBC ) count and neutrophil to lymphocyte ( N/L ) ratio are predictors of death/myocardial infa rct ion in patients who have undergone coronary angiography .  We hypothesized that a pre-procedural elevated WBC count and an elevated N/L ratio would be a predictor of development of significant ventricular arrhythmias in subjects undergoing percutaneous coronary intervention ( PCI ) .  METHODS AND RESULTS We retrieved the data for all patients developing ventricular arrhythmia during PCI between 1999 to 2009 from our cath lab data base ( from 30,798 records ) , a total of 70 patients ( Group I ) , and tabulated their WBC counts and absolute neutrophil and lymphocyte counts as well as N/L ratios . We compared the data with a r and om group of age , gender , medications and pre-existing condition matched controls ( n=70 ) ( Group II ) . We also adjusted for amount of myocardium under jeopardy . Group I had a significantly higher total WBC count ( means 14,344 Vs 6852 ; 95 % CI ; p=0.0004 ) ; neutrophil count ( means 75.79 % Vs 58.06 % ; 95 % CI ; p < 0.0001 ) and N/L ratio ( means 3.79 Vs 1.56 ; 95 % CI ; p < 0.0001 ) [ means compared with t test ] . CONCLUSION Our data suggests a pre-procedural elevated WBC count , neutrophils and elevated N/L ratio are predictors of significant ventricular arrhythmias in patients undergoing percutaneous coronary intervention ( PCI ) Background Atrial fibrillation ( AF ) recurrence after ablation is difficult to predict . The development of AF is associated with inflammation , and inflammatory markers such as big endothelin-1 ( big ET-1 ) reflect inflammatory status . It is unknown , however , whether big ET-1 can be used as a predictor for AF recurrence . The aim of this study was to investigate the relationship between plasma levels of big ET-1 and AF recurrence . Methods A total of 158 patients who had undergone primary ablation for symptomatic and /or drug-refractory AF , including 103 with paroxysmal and 55 with persistent AF , were included in this study . Left atrial diameter was measured with echocardiography and plasma big ET-1 levels with ELISA . All patients were followed up for at least 12 months and AF recurrence defined as an episode of AF lasting ≥ 30 s , with or without atrial flutter or atrial tachycardia . Results The AF recurrence rate was 44.9 % ( 71/158 ) during the median follow-up period of 22 ( 13 , 40 ) months . Plasma levels of big ET-1 in the recurrence group were higher than those in the non-recurrence group in all patients [ 0.80 ( 0.54 , 1.30 ) vs. 0.57 ( 0.48 , 0.72 ) fmol·L−1 , p = 0.001 ] , in patients with paroxysmal AF [ 0.81 ( 0.46 , 1.30 ) vs. 0.57 ( 0.48 , 0.70 ) fmol·L−1 , p = 0.009 ] as well as in patients with persistent AF [ 0.77 ( 0.57 , 1.28 ) vs. 0.57 ( 0.49 , 0.89 ) fmol·L−1 , p = 0.034 ] . Multiple logistic regression analyses showed that plasma levels of big ET-1 were associated with AF recurrence in patients with paroxysmal AF ( p = 0.037 ) . Kaplan-Meier analysis demonstrated that the sinus rhythm maintenance rate was lower in patients with higher big ET-1 levels than those with lower levels ( p < 0.05 ) . Conclusions Baseline plasma big ET-1 levels are associated with AF recurrence after primary ablation procedure in patients with paroxysmal AF , and may be used in the prediction of AF recurrence in these patients .ZusammenfassungHintergrundDas Wiederauftreten von Vorhofflimmern ( VF ) nach Ablation ist schwer vorherzusagen . VF ist mit Entzündungsprozessen vergesellschaftet , und Entzündungsmarker wie Big-Endothelin-1 ( Big-ET-1 ) spiegeln den Entzündungsstatus wider . Es ist jedoch nicht bekannt , ob Big-ET-1 als Prädiktor des Wiederauftretens von VF verwendet werden kann . Ziel dieser Studie war die Untersuchung der Beziehung zwischen Big-ET-1-Plasmaspiegel und einem VF-Rezidiv . Method enAn der Studie nahmen insgesamt 158 Patienten mit Zust and nach primärer Ablation wegen symptomatischem und/oder pharmakotherapieresistentem VF teil , darunter 103 mit paroxysmalem und 55 mit persistierendem VF . Der Durchmesser des linken Vorhofs wurde echokardiographisch und der ET-1-Plasmaspiegel per ELISA-Test ermittelt . Alle Patienten wurden mindestens 12 Monate lang nachbeobachtet , ein VF-Rezidiv war als VF-Episode ≥ 30 s definiert , mit oder ohne Vorhofflattern oder Vorhoftachykardie . ErgebnisseDie VF-Rezidivrate betrug 44,9 % ( 71/158 ) i m Lauf der mittleren Nachbeobachtungszeit von 22 ( 13–44 ) Monaten . In der Rezidivgruppe waren die ET-1-Plasmaspiegel höher als in der Gruppe ohne Rezidiv , und zwar bei allen Patienten [ 0,80 ( 0,54–1,30 ) vs. 0,57 ( 0,48–0,72 ) fmol/l , p = 0,001 ] , bei Patienten mit paroxysmalem VF [ 0,81 ( 0,46–1,30 ) vs. 0,57 ( 0,48–0,70 ) fmol/l , p = 0,009 ] sowie bei Patienten mit persistierendem VF [ 0,77 ( 0,57–1,28 ) vs. 0,57 ( 0,49–0,89 ) fmol/l , p = 0,034 ] . Multiple logistische Regressionsanalysen zeigten , dass bei Patienten mit paroxysmalem VF ein Zusammenhang zwischen dem ET-1-Plasmaspiegel und dem VF-Rezidiv best and ( p = 0,037 ) . Die Kaplan-Meier-Analyse ergab , dass die Sinusrhythmuserhaltungsrate bei Patienten mit höheren ET-1-Spiegeln geringer war als bei Patienten mit niedrigeren Spiegeln ( p < 0,05).SchlussfolgerungenBei Patienten mit paroxysmalem VF und Zust and nach primärer Ablation stehen die Ausgangswerte von ET-1 i m Plasma in Zusammenhang mit dem Wiederauftreten von VF und können bei solchen Patienten zur Vorhersage eines VF-Rezidivs eingesetzt werden BACKGROUND Systemic inflammation is accepted as one of the pathophysiological mechanisms of atrial fibrillation ( AF ) . The role of inflammation has been shown previously . Interleukin ( IL ) system is the main modulator of the inflammatory responses and genetic polymorphisms of IL-1 cluster genes are associated with increased risk for inflammatory diseases . OBJECTIVES To investigate the association between polymorphisms of IL-1 cluster genes and lone AF . SUBJECTS AND METHODS DNA sample s were collected from 70 proven lone AF patients and 70 healthy subjects . Genomic DNA was typed for the variable number of the t and em repeat ( VNTR ) IL-1 receptor antagonist ( RN ) gene polymorphism , IL-1B -511 C > T(rs16944 ) promoter polymorphism , and + 3953 C > T(rs1143634 ) polymorphism in exon 5 by polymerase chain reaction . RESULTS In lone AF group the frequency of IL-1RN2/2 and IL-1RN1/2 genotypes were higher than in the control group ( 7.2 % vs 4.3 % and 48.5 % vs 22.8 % , respectively ; χ(2 ) = 14.1 ; P = 0.028 ) . The frequency of allele 2 was significantly higher in the lone AF group ( 32.1 % vs 15.7 % ; χ(2 ) = 10.7 ; P = 0.005 ) . Allele and genotype distribution of IL-1B -511 C > T and + 3953 C > T polymorphisms were not statistically different between the groups . C-reactive protein ( CRP ) levels were higher in lone AF patients compared to the control group ( median = 1.25 , interquartile range [ IQR ] = 0.85 vs median = 1.08 , IQR 0.46 mg/L , respectively ; P = 0.02 ) . In multivariate regression analysis , presence of allele 2 of IL-1 VNTR polymorphism and elevated plasma high-sensitive-CRP levels were the independent predictors of lone AF . CONCLUSION Presence of allele 2 of VNTR polymorphism of IL-1RN gene may cause increased risk for lone AF probably due to the inadequate limitation of inflammatory reactions Background and Purpose — The increased risk of stroke and thromboembolism in atrial fibrillation ( AF ) may be related to a prothrombotic or hypercoagulable state , with abnormalities of hemostasis and platelet activation . To investigate the role of platelets in AF and the influence of antithrombotic therapy , we developed and then applied a new assay to detect the absolute amount of P-selectin per platelet ( pP-selectin ) based on cell lysis . Thus , pP-selectin in AF patients was compared with that of healthy controls and also with plasma soluble P-selectin ( sP-selectin ) and & bgr;-thromboglobulin as established indices of platelet activation . Methods mdash ; We studied 122 patients ( mean [ SD ] age , 71 [ 9 ] years ; 65 men ) with chronic AF of > 6 weeks ’ duration : 34 were not on antithrombotic therapy , 30 were taking aspirin ( 75 to 300 mg/d ) , and 58 were fully anticoagulated with warfarin .  pP-selectin was compared with sP-selectin and  plasma & bgr;-thromboglobulin levels ( enzyme-linked immunosorbent assay ) . Results were compared with those of 23 healthy controls ( mean [ SD ] age , 74 [ 9 ] years ; 7 men ) in sinus rhythm . Results — pP-selectin was significantly lower in AF patients on no antithrombotic therapy ( P ∓0.03 ) than in healthy controls , but sP-selectin and & bgr;-thromboglobulin levels were not significantly different and did not differ in patients taking aspirin or warfarin .  However , pP-selectin was lower in patients with AF on aspirin than in those on warfarin ( P < 0.05 ) . pP-selectin/sP-selectin correlated significantly in healthy controls ( r ∓0.47 , P ∓0.03 ) but inversely ( r ∓−0.43 , P ∓0.03 ) in AF patients on no antithrombotic therapy . Conclusions — Lower levels of pP-selectin may represent a depletion of pP-selectin after platelet activation in AF . Aspirin further decreases pP-selectin levels compared with warfarin . On the basis of the principle of platelet lysis , we demonstrate that it is possible to determine the amount of P-selectin per platelet , which may be regulated in the megakaryocyte through a cyclooxygenase-dependent pathway Background Myeloperoxidase ( MPO ) has been associated with the development of atrial fibrillation ( AF ) , but its impact on the recurrence of AF after catheter ablation has not been explored . This study investigated the effect of plasma MPO on recurrence after catheter ablation of paroxysmal AF . Methods and Results Two hundred eighty-eight consecutive patients with paroxysmal AF and who underwent circumferential pulmonary vein isolation were prospect ively enrolled . After a mean ± SD follow-up of 516 ± 204 ( 91–910 ) days , the recurrence rates were 16.9 % , 25.7 % , 29.7 % , and 38.0 % from the lowest MPO quartile to the highest MPO quartile , respectively ( P = 0.023 ) . After adjustment for age , sex , left atrial diameter , high-sensitivity C-reactive protein , and pulmonary vein isolation , there was an increased risk of recurrence in the subjects with the highest MPO quartile compared with those with the lowest quartile ( hazard ratio , 3.18 ; 95 % confidence interval , 2.12–5.23 ; P = 0.024 ) . As a continuous variable , MPO was also an independent predictor of recurrence ( hazard ratio , 2.12 ; 95 % confidence interval , 1.71–3.27 ; P = 0.032 ) . Conclusions Patients with high MPO levels were at an increased risk of AF recurrence after 
    Output:
    
Hematological parameters have significant ability to predict occurrence and recurrence of AF .