human
***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 —Early recurrence ( ER ) of atrial tachyarrhythmias during the first 3 months ( blanking period ) after atrial fibrillation ablation can be highly symptomatic , often requiring emergency treatment . Short-term steroid therapy may suppress ER during the blanking period . Methods and Results —We prospect ively enrolled 138 patients who were r and omly assigned to 2 groups ( steroid  group and control group ) . An intravenous bolus of 0.5 mg/kg of methylprednisolone for 2 days followed by 12 mg daily of oral methylprednisolone for 4 days was given to the steroid group patients . The primary end point was ER during the blanking period ( 3 months post ablation ) . During the blanking period , 51 of the 138 ( 37.0 % ) patients experienced ER after atrial fibrillation ablation . The steroid group had a lower rate of ER than the control group ( 15/64 [ 23.4 % ] versus 36/74 [ 48.6 % ] , P=0.003 ) . There was no difference between the 2 groups about late recurrence during a 24-month follow-up ( log-rank test , P=0.918 ) . In a multivariate analysis , short-term steroid therapy was independently associated with a lower rate of ER during the blanking period ( adjusted OR , 0.45 ; 95 % confidence interval , 0.25–0.83 ; P=0.01 ) . Conclusions —Periprocedural short-term moderate intensity steroid therapy reduces ER ( ≈3 months ) after catheter ablation of atrial fibrillation . It is not effective in preventing late ( 3≈24 m ) atrial fibrillation recurrence . Clinical Trial Registration —URL : www.who.int/ictrp ; Unique identifier : KCT0000107 BACKGROUND Atrial arrhythmias are associated with inflammation . The cause and effect of the association are unknown . OBJECTIVE The purpose of this study was to test the hypothesis that atrial tachyarrhythmias contribute to inflammation . METHODS We performed a prospect i ve observational study wherein C-reactive protein ( CRP ) and interleukin-6 ( IL-6 ) levels from the femoral vein and coronary sinus ( CS ) were compared before curative ablation for atrial flutter ( AFL ; n = 59 ) and paroxysmal supraventricular tachycardia ( SVT ; n = 110 ) . Follow-up levels were obtained at 1 and 6 months . RESULTS Peripheral levels of both biomarkers were significantly higher in the AFL group . After multivariate adjustment , only those in the AFL group who presented in AFL or atrial fibrillation ( AF ) had significantly elevated CRP levels ( odds ratio 1.26 ; P = .033 ) . Levels of each marker were similar in the CS and peripheral blood in the SVT group ; in the AFL group , both CRP and IL-6 were significantly lower in the CS than in the periphery ( P = .0076 and P = .0021 , respectively ) . CRP was significantly lower a median of 47 days after AFL ablation ( from a median of 6.28 mg/L to a median of 2.92 mg/L ; P = .028 ) and remained reduced at second follow-up . IL-6 decreased across three time points after AFL ablation ( P = .002 ) . No reduction in inflammatory biomarkers was observed after SVT ablation . CONCLUSIONS CRP and IL-6 levels are elevated in patients presenting in AFL . Given the lower CS values in these patients , their origin appears to be systemic rather than cardiac . Because these levels significantly fall after ablation of AFL , the atrial tachyarrhythmia appears to be the cause ( not the effect ) of the inflammation OBJECTIVES We sought to clarify the efficacy of corticosteroid therapy for preventing atrial fibrillation ( AF ) recurrence after pulmonary vein isolation ( PVI ) . BACKGROUND The inflammatory process may cause acute AF recurrence after PVI . However , no studies have examined the relationship between corticosteroid administration and AF recurrence after PVI . METHODS A total of 125 patients with paroxysmal AF were r and omized to receive either corticosteroids ( corticosteroid group ) or a placebo ( placebo group ) . In the corticosteroid group , intravenous hydrocortisone ( 2 mg/kg ) was given the day of the procedure , and oral prednisolone ( 0.5 mg/kg/day ) was administered for 3 days after the PVI . The body temperature and high-sensitivity C-reactive protein level were measured before and on each of the first 3 days after ablation . RESULTS The prevalence of immediate AF recurrence ( ≤3 days after the PVI ) was significantly lower in the corticosteroid group ( 7 % ) than in the placebo group ( 31 % ) . The maximum body temperature and C-reactive protein during the initial 3 days after ablation and the increase in the body temperature and C-reactive protein level from baseline were significantly lower in the corticosteroid group than in the placebo group . Corticosteroid treatment did not decrease AF recurrences between 4 and 30 days after ablation . The AF-free rate at 14 months post-ablation was greater in the corticosteroid group ( 85 % ) than in the placebo group ( 71 % , p=0.032 by the log-rank test ) . CONCLUSIONS Transient use of small amounts of corticosteroids shortly after AF ablation may be effective and safe for preventing not only immediate AF recurrences but also AF recurrences during the mid-term follow-up period after PVI BACKGROUND Atrial fibrillation ( AF ) recurrence after pulmonary vein isolation ( PVI ) is associated with PV to left atrium reconduction . OBJECTIVE The purpose of this study was to prospect ively determine if the use of intraprocedural corticosteroids to limit the extent of tissue edema and /or inflammation alters the prevalence of spontaneous and adenosine-induced acute PV reconnection after PVI . METHODS Prior to wide circumferential PVI , 45 patients received a single intravenous ( IV ) bolus of hydrocortisone 250 mg immediately after transseptal access ( steroid group ) . Another 45 consecutive patients underwent st and ard PVI without IV hydrocortisone  ( nonsteroid group ) . After PVI , all patients underwent adenosine testing to unmask dormant conduction . Patients were followed at 3 , 6 , and 12 months . RESULTS Dormant conduction was unmasked in a significantly higher proportion of PVs in the steroid group compared with the nonsteroid group ( 32.8 % of PVs [ 60/183 ] vs 21.1 % of PVs [ 37/175 ] , P = .03 ) . On multivariate generalized estimating equation analysis , steroid use remained independently associated with dormant PV conduction ( P = .03 ) . There was no difference in the segmental distribution of reconnection between the 2 groups . The 1-year freedom from recurrent AF did not differ between groups ( P = .37 ) . Radiofrequency time was significantly longer in the steroid group ( 58 ± 21 minutes vs 48 ± 18 minutes , P < .01 ) , whereas procedure duration and fluoroscopy time were comparable ( P = .55 and P = .44 , respectively ) . CONCLUSION A single bolus of hydrocortisone 250 mg IV prior to PVI results in greater radiofrequency requirements for PVI and a higher prevalence of dormant PV conduction unmasked by adenosine . The utility of these approaches requires evaluation in a long-term prospect i ve r and omized study Background Use of corticosteroids before and after atrial fibrillation ( AF ) ablation can decrease acute inflammation and reduce AF recurrence . Purpose To assess the efficacy of oral prednisone in improving the outcomes of pulmonary vein isolation with radiofrequency ablation and its effect on inflammatory cytokine . Methods A total of 60 patients with paroxysmal AF undergoing radiofrequency ablation were r and omized ( 1:1 ) to receive either 3 doses of 60 mg daily of oral prednisone or a placebo . Inflammatory cytokine levels ( TNF-α , IL-1 , IL6 , IL-8 ) were measured at baseline , prior to ablation , immediately after ablation , and 24 hours post ablation . Patients underwent 30 day event monitoring at 3 months , 6 months and 12 months post procedure . Results Immediate post ablation levels of inflammatory cytokines were lower in the steroid group when compared to the placebo group ; IL-6 : 9.0 ±7 vs 15.8 ±13 p=0.031 ; IL-8 : 10.5 ±9 vs 15.3 ±8 ; p=0.047 respectively . Acute PV reconnection rates during the procedure ( 7/23 % vs 10/36 % ; p = 0.39 ) , and RF ablation time ( 51±13 vs 56±11 min , p = 0.11 ) trended to be lower in the placebo group than the steroid group . There was no difference in the incidence of early recurrence of AF during the blanking period and freedom from AF off AAD at 12 months between both groups ( 5/17 % vs 8/27 % ; p = 0.347 and 21/70 % vs 18/60 % ; p=0.417 in placebo and steroid groups respectively ) . Conclusion Although oral corticosteroids have significant effect in lowering certain cytokines , it did not impact the clinical outcomes of AF ablation CONTEXT Atrial fibrillation ( AF ) is the most common arrhythmia to occur after cardiac surgery . An exaggerated inflammatory response has been proposed to be one etiological factor . OBJECTIVE To test whether intravenous corticosteroid administration after cardiac surgery prevents AF after cardiac surgery . DESIGN , SETTING , AND PATIENTS A double-blind , r and omized multicenter trial ( study enrollment August 2005-June 2006 ) in 3 university hospitals in Finl and of 241 consecutive patients without prior AF or flutter and scheduled to undergo first on-pump coronary artery bypass graft ( CABG ) surgery , aortic valve replacement , or combined CABG surgery and aortic valve replacement . INTERVENTION Patients were r and omized to receive either 100-mg hydrocortisone or matching placebo as follows : the first dose in the evening of the operative day , then 1 dose every 8 hours during the next 3 days . In addition , all patients received oral metoprolol ( 50 - 150 mg/d ) titrated to heart rate . MAIN OUTCOME MEASURE Occurrence of AF during the first 84 hours after cardiac surgery . RESULTS The incidence of postoperative AF was significantly lower in the hydrocortisone group ( 36/120 [ 30 % ] ) than in the placebo group ( 58/121 [ 48 % ] ; adjusted hazard ratio , 0.54 ; 95 % confidence interval , 0.35 - 0.83 ; P = .004 ; number needed to treat , 5.6 ) . Compared with placebo , patients receiving hydrocortisone did not have higher rates of superficial or deep wound infections , or other major complications . CONCLUSION Intravenous hydrocortisone reduced the incidence of AF after cardiac surgery . TRIAL REGISTRATION clinical trials.gov Identifier : NCT00442494 BACKGROUND Atrial fibrillation ( AF ) has been linked to an inflammatory process detected through various biomarkers , including C-Reactive Protein ( CRP ) . Early recurrence of AF within the first 3 months after curative AF ablation is not felt to reflect success or failure of the procedure . We hypothesized that this early recurrence is due to an inflammatory response to the ablation itself . We therefore sought to evaluate levels of CRP after AF ablation . METHODS We prospect ively enrolled subjects undergoing AF ablation . A control group of patients undergoing ablation for supraventricular tachycardia ( SVT ) was also enrolled . Each patient had CRP drawn on the day of the procedure ( prior to ablation ) and during their first follow-up ( median 49 days , interquartile range [ IQR ] 37 - 93 ) and second follow-up ( median 147 days , IQR 141 - 257 ) clinic visits . Patient interviews were performed and medical histories review ed for evidence of recurrent AF prior to the first follow-up . RESULTS CRP levels significantly increased from baseline to first follow-up in the AF ablation group ( P = 0.0017 ) . CRP did not significantly change after SVT ablation ( P = 0.92 ) . Seventeen ( 45 % ) of the AF subjects exhibited recurrence of AF prior to first follow-up . After adjusting for multiple potential confounders , AF ablation patients with recurrent AF prior to their first follow-up had a statistically significant greater odds of having an increase in CRP ( OR 21 , 95 % CI 1.1 - 417 , P = 0.045 ) . CONCLUSIONS AF ablation generates an inflammatory response that persists for several weeks . This inflammation may explain early recurrence of AF after curative ablation BACKGROUND The transient use of corticosteroid shortly after atrial fibrillation 
    Output:
    
agent
No clear benefit was observed for AF recurrence at 2 - 3 days , 1 or 24 months of follow-up .
Steroid use was associated with decreased risk of early AF recurrence 3 and 12 - 14 months after ablation .
***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 —Early recurrence ( ER ) of atrial tachyarrhythmias during the first 3 months ( blanking period ) after atrial fibrillation ablation can be highly symptomatic , often requiring emergency treatment . Short-term steroid therapy may suppress ER during the blanking period . Methods and Results —We prospect ively enrolled 138 patients who were r and omly assigned to 2 groups ( steroid  group and control group ) . An intravenous bolus of 0.5 mg/kg of methylprednisolone for 2 days followed by 12 mg daily of oral methylprednisolone for 4 days was given to the steroid group patients . The primary end point was ER during the blanking period ( 3 months post ablation ) . During the blanking period , 51 of the 138 ( 37.0 % ) patients experienced ER after atrial fibrillation ablation . The steroid group had a lower rate of ER than the control group ( 15/64 [ 23.4 % ] versus 36/74 [ 48.6 % ] , P=0.003 ) . There was no difference between the 2 groups about late recurrence during a 24-month follow-up ( log-rank test , P=0.918 ) . In a multivariate analysis , short-term steroid therapy was independently associated with a lower rate of ER during the blanking period ( adjusted OR , 0.45 ; 95 % confidence interval , 0.25–0.83 ; P=0.01 ) . Conclusions —Periprocedural short-term moderate intensity steroid therapy reduces ER ( ≈3 months ) after catheter ablation of atrial fibrillation . It is not effective in preventing late ( 3≈24 m ) atrial fibrillation recurrence . Clinical Trial Registration —URL : www.who.int/ictrp ; Unique identifier : KCT0000107 BACKGROUND Atrial arrhythmias are associated with inflammation . The cause and effect of the association are unknown . OBJECTIVE The purpose of this study was to test the hypothesis that atrial tachyarrhythmias contribute to inflammation . METHODS We performed a prospect i ve observational study wherein C-reactive protein ( CRP ) and interleukin-6 ( IL-6 ) levels from the femoral vein and coronary sinus ( CS ) were compared before curative ablation for atrial flutter ( AFL ; n = 59 ) and paroxysmal supraventricular tachycardia ( SVT ; n = 110 ) . Follow-up levels were obtained at 1 and 6 months . RESULTS Peripheral levels of both biomarkers were significantly higher in the AFL group . After multivariate adjustment , only those in the AFL group who presented in AFL or atrial fibrillation ( AF ) had significantly elevated CRP levels ( odds ratio 1.26 ; P = .033 ) . Levels of each marker were similar in the CS and peripheral blood in the SVT group ; in the AFL group , both CRP and IL-6 were significantly lower in the CS than in the periphery ( P = .0076 and P = .0021 , respectively ) . CRP was significantly lower a median of 47 days after AFL ablation ( from a median of 6.28 mg/L to a median of 2.92 mg/L ; P = .028 ) and remained reduced at second follow-up . IL-6 decreased across three time points after AFL ablation ( P = .002 ) . No reduction in inflammatory biomarkers was observed after SVT ablation . CONCLUSIONS CRP and IL-6 levels are elevated in patients presenting in AFL . Given the lower CS values in these patients , their origin appears to be systemic rather than cardiac . Because these levels significantly fall after ablation of AFL , the atrial tachyarrhythmia appears to be the cause ( not the effect ) of the inflammation OBJECTIVES We sought to clarify the efficacy of corticosteroid therapy for preventing atrial fibrillation ( AF ) recurrence after pulmonary vein isolation ( PVI ) . BACKGROUND The inflammatory process may cause acute AF recurrence after PVI . However , no studies have examined the relationship between corticosteroid administration and AF recurrence after PVI . METHODS A total of 125 patients with paroxysmal AF were r and omized to receive either corticosteroids ( corticosteroid group ) or a placebo ( placebo group ) . In the corticosteroid group , intravenous hydrocortisone ( 2 mg/kg ) was given the day of the procedure , and oral prednisolone ( 0.5 mg/kg/day ) was administered for 3 days after the PVI . The body temperature and high-sensitivity C-reactive protein level were measured before and on each of the first 3 days after ablation . RESULTS The prevalence of immediate AF recurrence ( ≤3 days after the PVI ) was significantly lower in the corticosteroid group ( 7 % ) than in the placebo group ( 31 % ) . The maximum body temperature and C-reactive protein during the initial 3 days after ablation and the increase in the body temperature and C-reactive protein level from baseline were significantly lower in the corticosteroid group than in the placebo group . Corticosteroid treatment did not decrease AF recurrences between 4 and 30 days after ablation . The AF-free rate at 14 months post-ablation was greater in the corticosteroid group ( 85 % ) than in the placebo group ( 71 % , p=0.032 by the log-rank test ) . CONCLUSIONS Transient use of small amounts of corticosteroids shortly after AF ablation may be effective and safe for preventing not only immediate AF recurrences but also AF recurrences during the mid-term follow-up period after PVI BACKGROUND Atrial fibrillation ( AF ) recurrence after pulmonary vein isolation ( PVI ) is associated with PV to left atrium reconduction . OBJECTIVE The purpose of this study was to prospect ively determine if the use of intraprocedural corticosteroids to limit the extent of tissue edema and /or inflammation alters the prevalence of spontaneous and adenosine-induced acute PV reconnection after PVI . METHODS Prior to wide circumferential PVI , 45 patients received a single intravenous ( IV ) bolus of hydrocortisone 250 mg immediately after transseptal access ( steroid group ) . Another 45 consecutive patients underwent st and ard PVI without IV hydrocortisone  ( nonsteroid group ) . After PVI , all patients underwent adenosine testing to unmask dormant conduction . Patients were followed at 3 , 6 , and 12 months . RESULTS Dormant conduction was unmasked in a significantly higher proportion of PVs in the steroid group compared with the nonsteroid group ( 32.8 % of PVs [ 60/183 ] vs 21.1 % of PVs [ 37/175 ] , P = .03 ) . On multivariate generalized estimating equation analysis , steroid use remained independently associated with dormant PV conduction ( P = .03 ) . There was no difference in the segmental distribution of reconnection between the 2 groups . The 1-year freedom from recurrent AF did not differ between groups ( P = .37 ) . Radiofrequency time was significantly longer in the steroid group ( 58 ± 21 minutes vs 48 ± 18 minutes , P < .01 ) , whereas procedure duration and fluoroscopy time were comparable ( P = .55 and P = .44 , respectively ) . CONCLUSION A single bolus of hydrocortisone 250 mg IV prior to PVI results in greater radiofrequency requirements for PVI and a higher prevalence of dormant PV conduction unmasked by adenosine . The utility of these approaches requires evaluation in a long-term prospect i ve r and omized study Background Use of corticosteroids before and after atrial fibrillation ( AF ) ablation can decrease acute inflammation and reduce AF recurrence . Purpose To assess the efficacy of oral prednisone in improving the outcomes of pulmonary vein isolation with radiofrequency ablation and its effect on inflammatory cytokine . Methods A total of 60 patients with paroxysmal AF undergoing radiofrequency ablation were r and omized ( 1:1 ) to receive either 3 doses of 60 mg daily of oral prednisone or a placebo . Inflammatory cytokine levels ( TNF-α , IL-1 , IL6 , IL-8 ) were measured at baseline , prior to ablation , immediately after ablation , and 24 hours post ablation . Patients underwent 30 day event monitoring at 3 months , 6 months and 12 months post procedure . Results Immediate post ablation levels of inflammatory cytokines were lower in the steroid group when compared to the placebo group ; IL-6 : 9.0 ±7 vs 15.8 ±13 p=0.031 ; IL-8 : 10.5 ±9 vs 15.3 ±8 ; p=0.047 respectively . Acute PV reconnection rates during the procedure ( 7/23 % vs 10/36 % ; p = 0.39 ) , and RF ablation time ( 51±13 vs 56±11 min , p = 0.11 ) trended to be lower in the placebo group than the steroid group . There was no difference in the incidence of early recurrence of AF during the blanking period and freedom from AF off AAD at 12 months between both groups ( 5/17 % vs 8/27 % ; p = 0.347 and 21/70 % vs 18/60 % ; p=0.417 in placebo and steroid groups respectively ) . Conclusion Although oral corticosteroids have significant effect in lowering certain cytokines , it did not impact the clinical outcomes of AF ablation CONTEXT Atrial fibrillation ( AF ) is the most common arrhythmia to occur after cardiac surgery . An exaggerated inflammatory response has been proposed to be one etiological factor . OBJECTIVE To test whether intravenous corticosteroid administration after cardiac surgery prevents AF after cardiac surgery . DESIGN , SETTING , AND PATIENTS A double-blind , r and omized multicenter trial ( study enrollment August 2005-June 2006 ) in 3 university hospitals in Finl and of 241 consecutive patients without prior AF or flutter and scheduled to undergo first on-pump coronary artery bypass graft ( CABG ) surgery , aortic valve replacement , or combined CABG surgery and aortic valve replacement . INTERVENTION Patients were r and omized to receive either 100-mg hydrocortisone or matching placebo as follows : the first dose in the evening of the operative day , then 1 dose every 8 hours during the next 3 days . In addition , all patients received oral metoprolol ( 50 - 150 mg/d ) titrated to heart rate . MAIN OUTCOME MEASURE Occurrence of AF during the first 84 hours after cardiac surgery . RESULTS The incidence of postoperative AF was significantly lower in the hydrocortisone group ( 36/120 [ 30 % ] ) than in the placebo group ( 58/121 [ 48 % ] ; adjusted hazard ratio , 0.54 ; 95 % confidence interval , 0.35 - 0.83 ; P = .004 ; number needed to treat , 5.6 ) . Compared with placebo , patients receiving hydrocortisone did not have higher rates of superficial or deep wound infections , or other major complications . CONCLUSION Intravenous hydrocortisone reduced the incidence of AF after cardiac surgery . TRIAL REGISTRATION clinical trials.gov Identifier : NCT00442494 BACKGROUND Atrial fibrillation ( AF ) has been linked to an inflammatory process detected through various biomarkers , including C-Reactive Protein ( CRP ) . Early recurrence of AF within the first 3 months after curative AF ablation is not felt to reflect success or failure of the procedure . We hypothesized that this early recurrence is due to an inflammatory response to the ablation itself . We therefore sought to evaluate levels of CRP after AF ablation . METHODS We prospect ively enrolled subjects undergoing AF ablation . A control group of patients undergoing ablation for supraventricular tachycardia ( SVT ) was also enrolled . Each patient had CRP drawn on the day of the procedure ( prior to ablation ) and during their first follow-up ( median 49 days , interquartile range [ IQR ] 37 - 93 ) and second follow-up ( median 147 days , IQR 141 - 257 ) clinic visits . Patient interviews were performed and medical histories review ed for evidence of recurrent AF prior to the first follow-up . RESULTS CRP levels significantly increased from baseline to first follow-up in the AF ablation group ( P = 0.0017 ) . CRP did not significantly change after SVT ablation ( P = 0.92 ) . Seventeen ( 45 % ) of the AF subjects exhibited recurrence of AF prior to first follow-up . After adjusting for multiple potential confounders , AF ablation patients with recurrent AF prior to their first follow-up had a statistically significant greater odds of having an increase in CRP ( OR 21 , 95 % CI 1.1 - 417 , P = 0.045 ) . CONCLUSIONS AF ablation generates an inflammatory response that persists for several weeks . This inflammation may explain early recurrence of AF after curative ablation BACKGROUND The transient use of corticosteroid shortly after atrial fibrillation 
    Output:
    