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 and Purpose — Atrial fibrillation is associated with decline of cognitive function . Observational evidence suggests that anticoagulation might protect against this decline . We report the first r and omized controlled trial evidence on the effect of anticoagulation on cognitive function in elderly patients with atrial fibrillation . Methods — A total of 973 patients aged ≥75 years with atrial fibrillation were recruited from primary care and r and omly assigned to warfarin ( n=488 ; target international normalized ratio , 2–3 ) or aspirin ( n=485 ; 75 mg/d ) . Neither participants nor investigators were masked to group assignment . Follow-up was for a mean of 2.7 years ( SD , 1.2 ) . Cognitive outcome was assessed using the Mini-Mental State Examination at 9- , 21- , and 33-month follow-up . Participants who had a stroke were censored from the analysis , which was by intention to treat with imputation for missing data . Results — There was no difference between mean Mini-Mental State Examination scores in people assigned to warfarin or aspirin at 9 or 21 months . At 33-month follow-up , there was a nonsignificant difference of 0.56 in favor of warfarin that decreased to 0.49 ( 95 % confidence interval , –0.01 to 0.98 ) after imputation . Conclusions — We found no evidence that anticoagulation confers clinical ly important protection over aspirin against cognitive decline as measured by the Mini-Mental State Examination in atrial fibrillation in the first 33 months of treatment other than that provided by preventing clinical stroke . Clinical Trial Registration — URL : http://www.controlled-trials.com . Unique identifier : IS RCT N89345269 BACKGROUND Atrial fibrillation is an important cause of morbidity and mortality worldwide , but scant data are available for long-term outcomes in individuals outside North America or Europe , especially in primary care setting s. METHODS We did a cohort study using a prospect i ve registry of patients in 47 countries who presented to a hospital emergency department with atrial fibrillation or atrial flutter as a primary or secondary diagnosis . 15 400 individuals were enrolled to determine the occurrence of death and strokes ( the primary outcomes ) in this cohort over eight geographical regions ( North America , western Europe , and Australia ; South America ; eastern Europe ; the Middle East and Mediterranean crescent ; sub-Saharan Africa ; India ; China ; and southeast Asia ) 1 year after attending the emergency department . Patients from North America , western Europe , and Australia were used as the reference population , and compared with patients from the other seven regions FINDINGS Between Dec 24 , 2007 , and Oct 21 , 2011 , we enrolled 15 400 individuals to the registry . Follow-up was complete for 15 361 ( 99·7 % ) , of whom 1758 ( 11 % ) died within 1 year . Fewer deaths occurred among patients presenting to the emergency department with a primary diagnosis of atrial fibrillation compared with patients who had atrial fibrillation as a secondary diagnosis ( 377 [ 6 % ] of 6825 patients vs 1381 [ 16 % ] of 8536 , p<0·0001 ) . Twice as many patients had died by 1 year in South America ( 192 [ 17 % ] of 1132 ) and Africa ( 225 [ 20 % ] of 1137 ) compared with North America , western Europe , and Australia ( 366 [ 10 % ] of 3800 , p<0·0001 ) . Heart failure was the most common cause of death ( 519 [ 30 % ] of 1758 ) ; stroke caused 148 ( 8 % ) deaths . 604 ( 4 % ) of 15361 patients had had a stroke by 1 year ; 170 ( 3 % ) of 6825 for whom atrial fibrillation was a primary diagnosis and 434 ( 5 % ) of 8536 for whom it was a secondary diagnosis ( p<0·0001 ) . The highest number of strokes occurred in patients in Africa ( 89 [ 8 % ] of 1137 ) , China ( 143 [ 7 % ] of 2023 ) , and southeast Asia ( 88 [ 7 % ] of 1331 ) and the lowest occurred in India ( 20 [ < 1 % ] of 2536 ) . 94 ( 3 % ) of 3800 patients in North America , western Europe , and Australia had a stroke . INTERPRETATION Marked unexplained inter-regional variations in the occurrence of stroke and mortality suggest that factors other than clinical variables might be important . Prevention of death from heart failure should be a major priority in the treatment of atrial fibrillation . FUNDING Boehringer Ingelheim OBJECTIVES The study sought to evaluate clinical outcomes in clinical practice with rhythm control versus rate control strategy for management of atrial fibrillation ( AF ) . BACKGROUND R and omized trials have not demonstrated significant differences in stroke , heart failure , or mortality between rhythm and rate control strategies . The comparative outcomes in contemporary clinical practice are not well described . METHODS Patients managed with a rhythm control strategy targeting maintenance of sinus rhythm were retrospectively  compared with a strategy of rate control alone in a AF registry across various U.S. practice setting s. Unadjusted and adjusted ( inverse-propensity weighted ) outcomes were estimated . RESULTS The overall study population ( N = 6,988 ) had a median of 74 ( 65 to 81 ) years of age , 56 % were males , 77 % had first detected or paroxysmal AF , and 68 % had CHADS2 score ≥2 . In unadjusted analyses , rhythm control was associated with lower all-cause death , cardiovascular death , first stroke/non- central nervous system systemic embolization/transient ischemic attack , or first major bleeding event ( all p < 0.05 ) ; no difference in new onset heart failure ( p = 0.28 ) ; and more frequent cardiovascular hospitalizations ( p = 0.0006 ) . There was no difference in the incidence of pacemaker , defibrillator , or cardiac resynchronization device implantations ( p = 0.99 ) . In adjusted analyses , there were no statistical differences in clinical outcomes between rhythm control and rate control treated patients ( all p > 0.05 ) ; however , rhythm control was associated with more cardiovascular hospitalizations ( hazard ratio : 1.24 ; 95 % confidence interval : 1.10 to 1.39 ; p = 0.0003 ) . CONCLUSIONS Among patients with AF , rhythm control was not superior to rate control strategy for outcomes of stroke , heart failure , or mortality , but was associated with more cardiovascular hospitalizations Background : Atrial fibrillation ( AF ) and heart failure ( HF ) often coexist . The aim was to investigate whether restoring sinus rhythm ( SR ) could improve cardiac function , symptoms , exercise capacity and quality of life ( QoL ) in patients with chronic heart failure . Methods : Patients with HF and persistent AF receiving guideline -recommended treatments , including anticoagulants , were eligible for the study . Patients were r and omised to either rhythm ( treated with amiodarone for at least 3 months prior to attempting biphasic external cardioversion and continued amiodarone long-term if SR was restored ) or rate control . Anticoagulants were continued throughout the study regardless of rhythm , unless contraindications developed . Both groups were treated with beta blockers and /or digoxin to reduce the heart rate to < 80 bpm at rest and < 110 bpm after walking . Symptoms , walk distance ( 6-minute corridor walk test , 6MWT ) , QoL and cardiac function were assessed at baseline and 1 year . Results : 61 patients with HF and persistent AF ( median duration 14 months ( IQR 5 to 32 ) ) were r and omly assigned to a rate or rhythm control strategy . Of patients assigned to rhythm control ( n = 30 ) , 66 % were in SR at 1 year , and 90 % of those assigned to rate control ( n = 31 ) achieved the heart rate target . At 1 year , NYHA class ( p = 0.424 ) and 6MWT distance ( p = 0.342 ) were similar between groups but patients assigned to rhythm control had improved LV function ( p = 0.014 ) , NT-proBNP concentration ( p = 0.046 ) and QoL ( p = 0.019 ) compared with those assigned to rate control . Greatest improvement was seen in patients in whom SR was maintained . Conclusion : Restoring SR in patients with AF and heart failure may improve QoL and LV function when compared with a strategy of rate control BACKGROUND Atrial fibrillation ( AF ) is the most common sustained arrhythmia with serious clinical consequences in the absence of treatment . However , there are limited data on the treatment of these patients in Argentina . The objective was to describe the therapeutic management of patients with nonacute AF by Argentinean cardiologists and to determine the incidence of clinical events after 12 months follow-up . METHODS The Atrial Fibrillation study in Argentina ( FARAON ) was an observational , descriptive , prospect i ve , national , and multicentric study that included out patients with AF , followed for 12 months . The study included 38 sites in Argentina . Each research er included the first 10 patients who met the inclusion criteria of being over 21 and also being an AF carrier documented by electrocardiogram or Holter within 12 months prior to or at the time of enrollment . RESULTS A total of 373 patients were included , mean age 70 ± 11.5 years , 40 % women ; 65 % had AF rhythm at the time of inclusion , 57 % had permanent AF , and 56 % were asymptomatic . At the time of enrollment , 40 % of physicians opted for rhythm control strategy . β-blockers and amiodarone were the most used drugs . Patients with rhythm control drugs had higher success rate than those with frequency control drug therapy ( 80 % vs 57 % ) . CONCLUSION Cardiologists in Argentina receive patients with AF that are mostly permanent AF . More than half of the patients are asymptomatic . They opt primarily by controlling the pace . When choosing antiarrhythmic drugs , nearly half of them indicated amiodarone BACKGROUND The restoration and maintenance of sinus rhythm is a desirable goal in patients with atrial fibrillation , because the prevention of recurrences can improve cardiac function and relieve symptoms . Uncontrolled studies have suggested that amiodarone in low doses may be more effective and safer than other agents in preventing recurrence , but this agent has not been tested in a large , r and omized trial . METHODS We undertook a prospect i ve , multicenter trial to test the hypothesis that low doses of amiodarone would be more efficacious in preventing recurrent atrial fibrillation than therapy with sotalol or propafenone . We r and omly assigned patients who had had at least one episode of atrial fibrillation within the previous six months to amiodarone or to sotalol or propafenone , given in an open-label fashion . The patients in the group assigned to sotalol or propafenone underwent a second r and omization to determine whether they would receive sotalol or propafenone first ; if the first drug was unsuccessful the second agent was prescribed . Loading doses of the drugs were administered and electrical cardioversion was performed ( if necessary ) within 21 days after r and omization for all patients in both groups . The follow-up period began 21 days after r and omization . The primary end point was the length of time to a first recurrence of atrial fibrillation . RESULTS Of the 403 patients in the study , 201 were assigned to  amiodarone  and 202 to either sotalol ( 101 patients ) or propafenone ( 101 patients ) . After a mean of 16 months of follow-up , 71 of the patients who were assigned to amiodarone ( 35 percent ) and 127 of those who were assigned to sotalol or propafenone ( 63 percent ) had a recurrence of atrial fibrillation ( P<0.001 ) . Adverse events requiring the discontinuation of drug therapy occurred in 18 percent of the patients receiving amiodarone , as compared with 11 percent of those treated with sotalol or propafenone ( P=0.06 ) . CONCLUSIONS Amiodarone is more effective than sotalol or propafenone for the prevention of recurrences of atrial fibrillation OBJECTIVES This study was design ed to compare two treatment strategies in patients with atrial fibrillation(AF ) :  rhythm-control ( restoration and maintenance of sinus rhythm ) and rate-control ( pharmacologic or invasive rate-control and anticoagulation ) . BACKGROUND Atrial fibrillation is the most common arrhythmia . It is unclear whether a strategy of rhythm- or rate-control is better in terms of mortality , morbidity , and quality of life . METHODS The Strategies of Treatment of Atrial Fibrillation ( STAF ) multicenter pilot trial r and omized 200 patients ( 100 per group ) with persistent AF to rhythm- or rate-control .  The combined primary end point was a combination of death , cardiopulmonary resuscitation , cerebrovascular event , and systemic embolism . RESULTS After 19.6 + /- 8.9 months ( range 0 to 36 months ) there was no difference in the primary end point between rhythm-control ( 9/ 
    Output:
    
agent
As such , evidence was insufficient to recommend rhythm or rate control as the first-line therapy for AF in older adults .
***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 and Purpose — Atrial fibrillation is associated with decline of cognitive function . Observational evidence suggests that anticoagulation might protect against this decline . We report the first r and omized controlled trial evidence on the effect of anticoagulation on cognitive function in elderly patients with atrial fibrillation . Methods — A total of 973 patients aged ≥75 years with atrial fibrillation were recruited from primary care and r and omly assigned to warfarin ( n=488 ; target international normalized ratio , 2–3 ) or aspirin ( n=485 ; 75 mg/d ) . Neither participants nor investigators were masked to group assignment . Follow-up was for a mean of 2.7 years ( SD , 1.2 ) . Cognitive outcome was assessed using the Mini-Mental State Examination at 9- , 21- , and 33-month follow-up . Participants who had a stroke were censored from the analysis , which was by intention to treat with imputation for missing data . Results — There was no difference between mean Mini-Mental State Examination scores in people assigned to warfarin or aspirin at 9 or 21 months . At 33-month follow-up , there was a nonsignificant difference of 0.56 in favor of warfarin that decreased to 0.49 ( 95 % confidence interval , –0.01 to 0.98 ) after imputation . Conclusions — We found no evidence that anticoagulation confers clinical ly important protection over aspirin against cognitive decline as measured by the Mini-Mental State Examination in atrial fibrillation in the first 33 months of treatment other than that provided by preventing clinical stroke . Clinical Trial Registration — URL : http://www.controlled-trials.com . Unique identifier : IS RCT N89345269 BACKGROUND Atrial fibrillation is an important cause of morbidity and mortality worldwide , but scant data are available for long-term outcomes in individuals outside North America or Europe , especially in primary care setting s. METHODS We did a cohort study using a prospect i ve registry of patients in 47 countries who presented to a hospital emergency department with atrial fibrillation or atrial flutter as a primary or secondary diagnosis . 15 400 individuals were enrolled to determine the occurrence of death and strokes ( the primary outcomes ) in this cohort over eight geographical regions ( North America , western Europe , and Australia ; South America ; eastern Europe ; the Middle East and Mediterranean crescent ; sub-Saharan Africa ; India ; China ; and southeast Asia ) 1 year after attending the emergency department . Patients from North America , western Europe , and Australia were used as the reference population , and compared with patients from the other seven regions FINDINGS Between Dec 24 , 2007 , and Oct 21 , 2011 , we enrolled 15 400 individuals to the registry . Follow-up was complete for 15 361 ( 99·7 % ) , of whom 1758 ( 11 % ) died within 1 year . Fewer deaths occurred among patients presenting to the emergency department with a primary diagnosis of atrial fibrillation compared with patients who had atrial fibrillation as a secondary diagnosis ( 377 [ 6 % ] of 6825 patients vs 1381 [ 16 % ] of 8536 , p<0·0001 ) . Twice as many patients had died by 1 year in South America ( 192 [ 17 % ] of 1132 ) and Africa ( 225 [ 20 % ] of 1137 ) compared with North America , western Europe , and Australia ( 366 [ 10 % ] of 3800 , p<0·0001 ) . Heart failure was the most common cause of death ( 519 [ 30 % ] of 1758 ) ; stroke caused 148 ( 8 % ) deaths . 604 ( 4 % ) of 15361 patients had had a stroke by 1 year ; 170 ( 3 % ) of 6825 for whom atrial fibrillation was a primary diagnosis and 434 ( 5 % ) of 8536 for whom it was a secondary diagnosis ( p<0·0001 ) . The highest number of strokes occurred in patients in Africa ( 89 [ 8 % ] of 1137 ) , China ( 143 [ 7 % ] of 2023 ) , and southeast Asia ( 88 [ 7 % ] of 1331 ) and the lowest occurred in India ( 20 [ < 1 % ] of 2536 ) . 94 ( 3 % ) of 3800 patients in North America , western Europe , and Australia had a stroke . INTERPRETATION Marked unexplained inter-regional variations in the occurrence of stroke and mortality suggest that factors other than clinical variables might be important . Prevention of death from heart failure should be a major priority in the treatment of atrial fibrillation . FUNDING Boehringer Ingelheim OBJECTIVES The study sought to evaluate clinical outcomes in clinical practice with rhythm control versus rate control strategy for management of atrial fibrillation ( AF ) . BACKGROUND R and omized trials have not demonstrated significant differences in stroke , heart failure , or mortality between rhythm and rate control strategies . The comparative outcomes in contemporary clinical practice are not well described . METHODS Patients managed with a rhythm control strategy targeting maintenance of sinus rhythm were retrospectively  compared with a strategy of rate control alone in a AF registry across various U.S. practice setting s. Unadjusted and adjusted ( inverse-propensity weighted ) outcomes were estimated . RESULTS The overall study population ( N = 6,988 ) had a median of 74 ( 65 to 81 ) years of age , 56 % were males , 77 % had first detected or paroxysmal AF , and 68 % had CHADS2 score ≥2 . In unadjusted analyses , rhythm control was associated with lower all-cause death , cardiovascular death , first stroke/non- central nervous system systemic embolization/transient ischemic attack , or first major bleeding event ( all p < 0.05 ) ; no difference in new onset heart failure ( p = 0.28 ) ; and more frequent cardiovascular hospitalizations ( p = 0.0006 ) . There was no difference in the incidence of pacemaker , defibrillator , or cardiac resynchronization device implantations ( p = 0.99 ) . In adjusted analyses , there were no statistical differences in clinical outcomes between rhythm control and rate control treated patients ( all p > 0.05 ) ; however , rhythm control was associated with more cardiovascular hospitalizations ( hazard ratio : 1.24 ; 95 % confidence interval : 1.10 to 1.39 ; p = 0.0003 ) . CONCLUSIONS Among patients with AF , rhythm control was not superior to rate control strategy for outcomes of stroke , heart failure , or mortality , but was associated with more cardiovascular hospitalizations Background : Atrial fibrillation ( AF ) and heart failure ( HF ) often coexist . The aim was to investigate whether restoring sinus rhythm ( SR ) could improve cardiac function , symptoms , exercise capacity and quality of life ( QoL ) in patients with chronic heart failure . Methods : Patients with HF and persistent AF receiving guideline -recommended treatments , including anticoagulants , were eligible for the study . Patients were r and omised to either rhythm ( treated with amiodarone for at least 3 months prior to attempting biphasic external cardioversion and continued amiodarone long-term if SR was restored ) or rate control . Anticoagulants were continued throughout the study regardless of rhythm , unless contraindications developed . Both groups were treated with beta blockers and /or digoxin to reduce the heart rate to < 80 bpm at rest and < 110 bpm after walking . Symptoms , walk distance ( 6-minute corridor walk test , 6MWT ) , QoL and cardiac function were assessed at baseline and 1 year . Results : 61 patients with HF and persistent AF ( median duration 14 months ( IQR 5 to 32 ) ) were r and omly assigned to a rate or rhythm control strategy . Of patients assigned to rhythm control ( n = 30 ) , 66 % were in SR at 1 year , and 90 % of those assigned to rate control ( n = 31 ) achieved the heart rate target . At 1 year , NYHA class ( p = 0.424 ) and 6MWT distance ( p = 0.342 ) were similar between groups but patients assigned to rhythm control had improved LV function ( p = 0.014 ) , NT-proBNP concentration ( p = 0.046 ) and QoL ( p = 0.019 ) compared with those assigned to rate control . Greatest improvement was seen in patients in whom SR was maintained . Conclusion : Restoring SR in patients with AF and heart failure may improve QoL and LV function when compared with a strategy of rate control BACKGROUND Atrial fibrillation ( AF ) is the most common sustained arrhythmia with serious clinical consequences in the absence of treatment . However , there are limited data on the treatment of these patients in Argentina . The objective was to describe the therapeutic management of patients with nonacute AF by Argentinean cardiologists and to determine the incidence of clinical events after 12 months follow-up . METHODS The Atrial Fibrillation study in Argentina ( FARAON ) was an observational , descriptive , prospect i ve , national , and multicentric study that included out patients with AF , followed for 12 months . The study included 38 sites in Argentina . Each research er included the first 10 patients who met the inclusion criteria of being over 21 and also being an AF carrier documented by electrocardiogram or Holter within 12 months prior to or at the time of enrollment . RESULTS A total of 373 patients were included , mean age 70 ± 11.5 years , 40 % women ; 65 % had AF rhythm at the time of inclusion , 57 % had permanent AF , and 56 % were asymptomatic . At the time of enrollment , 40 % of physicians opted for rhythm control strategy . β-blockers and amiodarone were the most used drugs . Patients with rhythm control drugs had higher success rate than those with frequency control drug therapy ( 80 % vs 57 % ) . CONCLUSION Cardiologists in Argentina receive patients with AF that are mostly permanent AF . More than half of the patients are asymptomatic . They opt primarily by controlling the pace . When choosing antiarrhythmic drugs , nearly half of them indicated amiodarone BACKGROUND The restoration and maintenance of sinus rhythm is a desirable goal in patients with atrial fibrillation , because the prevention of recurrences can improve cardiac function and relieve symptoms . Uncontrolled studies have suggested that amiodarone in low doses may be more effective and safer than other agents in preventing recurrence , but this agent has not been tested in a large , r and omized trial . METHODS We undertook a prospect i ve , multicenter trial to test the hypothesis that low doses of amiodarone would be more efficacious in preventing recurrent atrial fibrillation than therapy with sotalol or propafenone . We r and omly assigned patients who had had at least one episode of atrial fibrillation within the previous six months to amiodarone or to sotalol or propafenone , given in an open-label fashion . The patients in the group assigned to sotalol or propafenone underwent a second r and omization to determine whether they would receive sotalol or propafenone first ; if the first drug was unsuccessful the second agent was prescribed . Loading doses of the drugs were administered and electrical cardioversion was performed ( if necessary ) within 21 days after r and omization for all patients in both groups . The follow-up period began 21 days after r and omization . The primary end point was the length of time to a first recurrence of atrial fibrillation . RESULTS Of the 403 patients in the study , 201 were assigned to  amiodarone  and 202 to either sotalol ( 101 patients ) or propafenone ( 101 patients ) . After a mean of 16 months of follow-up , 71 of the patients who were assigned to amiodarone ( 35 percent ) and 127 of those who were assigned to sotalol or propafenone ( 63 percent ) had a recurrence of atrial fibrillation ( P<0.001 ) . Adverse events requiring the discontinuation of drug therapy occurred in 18 percent of the patients receiving amiodarone , as compared with 11 percent of those treated with sotalol or propafenone ( P=0.06 ) . CONCLUSIONS Amiodarone is more effective than sotalol or propafenone for the prevention of recurrences of atrial fibrillation OBJECTIVES This study was design ed to compare two treatment strategies in patients with atrial fibrillation(AF ) :  rhythm-control ( restoration and maintenance of sinus rhythm ) and rate-control ( pharmacologic or invasive rate-control and anticoagulation ) . BACKGROUND Atrial fibrillation is the most common arrhythmia . It is unclear whether a strategy of rhythm- or rate-control is better in terms of mortality , morbidity , and quality of life . METHODS The Strategies of Treatment of Atrial Fibrillation ( STAF ) multicenter pilot trial r and omized 200 patients ( 100 per group ) with persistent AF to rhythm- or rate-control .  The combined primary end point was a combination of death , cardiopulmonary resuscitation , cerebrovascular event , and systemic embolism . RESULTS After 19.6 + /- 8.9 months ( range 0 to 36 months ) there was no difference in the primary end point between rhythm-control ( 9/ 
    Output:
    