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 Amiodarone use was associated with an increased need for pacemaker insertion in a retrospective study of patients with atrial fibrillation ( AF ) and prior myocardial infa rct ion . The aims of this study were to determine prospect ively whether amiodarone increases the need for pacemakers in a general population of patients with AF and whether this effect is modified by sex . METHODS The study included 1005 patients with new-onset AF who were enrolled in the Fibrillation Registry Assessing Costs , Therapies , Adverse events , and Lifestyle ( FRACTAL ) .  Multivariable Cox regression models , including time-dependent covariates accounting for medication exposure , were used to evaluate the risk of pacemaker insertion associated with amiodarone use . RESULTS Amiodarone use was associated with an increased risk of pacemaker insertion ( hazard ratio [ HR ] , 2.01 ; 95 % confidence interval [ CI ] , 1.08 - 3.76 ) after adjustment for age , sex , atrial flutter , coronary artery disease , heart failure , and hypertension . The effect of amiodarone use was modified by sex , with a significant risk in women but not in men ( HR , 4.69 ; 95 % CI , 1.99 - 11.05 vs HR , 1.05 ; 95 % CI , 0.42 - 2.58 [ P = .02 ] ) . This interaction remained significant after adjustment for weight , body mass index , weight-adjusted amiodarone dose , and use of other antiarrhythmic or rate control drugs . CONCLUSION The risk of bradyarrhythmia requiring pacemaker insertion associated with amiodarone use for AF is significantly greater in women than in men , independent of weight or body mass index Patients with atrial fibrillation ( AF ) report impaired health-related quality of life ( QOL ) . Differences between men and women with AF have not been described and personality attributes such as somatization ( tendency to amplify benign bodily sensations ) may mediate potential gender differences in QOL . Patients with AF ( n = 264 , 59 % men ) who participated in the Canadian Trial of Atrial Fibrillation ( n = 403 ) completed vali date d QOL question naires at baseline , 3 months , and 12 months after antiarrhythmic drug treatment .  Women were significantly older than men and a greater proportion had hypertension , but other cardiac variables did not differ between women and men . At baseline , after controlling for significant clinical and demographic factors , women reported worse physical health ( p = 0.002 ) and functional capacity ( p < 0.001 ) , but not mental health or general well-being . Women also had more frequent and severe cardiac symptoms than men ( both p < 0.001 ) . Physical health improved significantly from baseline to 3 months for women ( p = 0.002 ) , but not for men ( p = 0.066 ) . Conversely , mental health improved for men ( p = 0.007 ) , but not for women . Cardiac symptom frequency and severity improved over time for women and men ( all p < 0.001 ) . Tendency to somatize predicted poor QOL , and women had higher scores than men ( p = 0.023 ) . However , after controlling for somatization , women still had worse physical function , functional capacity , and symptom burden than men . Independent of cardiac disease severity and age , women with AF had significantly more impaired QOL than men , specifically on domains related to physical rather than emotional functioning . Personality attributes may have a role in influencing QOL outcomes BACKGROUND AND PURPOSE Nonvalvular atrial fibrillation ( AF ) is a strong , independent risk factor for stroke , but the absolute rate of stroke varies widely among AF patients , importantly influencing the potential benefit of antithrombotic prophylaxis . We explore factors associated with ischemic stroke in AF patients taking aspirin .  METHODS We performed multivariate logistic regression analysis of 2012 participants given aspirin alone or in combination with low , inefficacious doses of warfarin in the Stroke Prevention in Atrial Fibrillation I-III trials followed for a mean of 2.0 years , during which 130 ischemic strokes were observed . RESULTS Age ( relative risk [RR]=1.8 per decade , P<0.001 ) , female sex ( RR=1.6 , P=0.01 ) , history of hypertension ( RR=2.0 , P<0.001 ) , systolic blood pressure > 160 mm Hg ( RR=2.3 , P<0.001 ) , and prior stroke or transient ischemic attack ( RR=2.9 , P<0.001 ) were independently associated with increased stroke risk . Regular consumption of > /=14 alcohol-containing drinks per week was associated with reduced stroke risk ( adjusted RR=0.4 , P=0.04 ) . Among SPAF III participants , estrogen hormone replacement therapy was associated with a higher risk of ischemic stroke ( adjusted RR=3.2 , P=0.007 ) . With the use of these variables , a risk stratification scheme for primary prevention separated participants into those with high ( 7.1%/y , 22 % of the cohort ) , moderate ( 2.6%/y , 37 % of the cohort ) , and low ( 0.9%/y , 41 % of the cohort ) rates of stroke . Ischemic strokes in low-risk participants were less often disabling ( P<0.001 ) . CONCLUSIONS Patients with AF who have high and low rates of stroke during treatment with  aspirin can be identified . However , validation of our risk stratification scheme is necessary before it can be applied with confidence to clinical management . Postmenopausal estrogen replacement therapy and moderate alcohol consumption may additionally modify the risk of stroke in AF , but these findings require confirmation BACKGROUND Warfarin reduces the risk of stroke in patients with atrial fibrillation but increases the risk of hemorrhage and is difficult to use . Dabigatran is a new oral direct thrombin inhibitor . METHODS In this noninferiority trial , we r and omly assigned 18,113 patients who had atrial fibrillation and a risk of stroke to receive , in a blinded fashion , fixed doses of dabigatran--110 mg or 150 mg twice daily -- or , in an unblinded fashion , adjusted-dose warfarin . The median duration of the follow-up period was 2.0 years . The primary outcome was stroke or systemic embolism . RESULTS Rates of the primary outcome were 1.69 % per year in the warfarin group , as compared with 1.53 % per year in the group that received 110 mg of dabigatran ( relative risk with dabigatran , 0.91 ; 95 % confidence interval [ CI ] , 0.74 to 1.11 ; P<0.001 for noninferiority ) and 1.11 % per year in the group that received 150 mg of dabigatran ( relative risk , 0.66 ; 95 % CI , 0.53 to 0.82 ; P<0.001 for superiority ) . The rate of major bleeding was 3.36 % per year in the warfarin group , as compared with 2.71 % per year in the group receiving 110 mg of dabigatran ( P=0.003 ) and 3.11 % per year in the group receiving 150 mg of dabigatran ( P=0.31 ) . The rate of hemorrhagic stroke was 0.38 % per year in the warfarin group , as compared with 0.12 % per year with 110 mg of dabigatran ( P<0.001 ) and 0.10 % per year with 150 mg of dabigatran ( P<0.001 ) . The mortality rate was 4.13 % per year in the warfarin group , as compared with 3.75 % per year with 110 mg of dabigatran ( P=0.13 ) and 3.64 % per year with 150 mg of dabigatran ( P=0.051 ) . CONCLUSIONS In patients with atrial fibrillation , dabigatran given at a dose of 110 mg was associated with rates of stroke and systemic embolism that were similar to those associated with warfarin , as well as lower rates of major hemorrhage .  Dabigatran administered at a dose of 150 mg , as compared with warfarin , was associated with lower rates of stroke and systemic embolism but similar rates of major hemorrhage . ( Clinical Trials.gov number , NCT00262600 . BACKGROUND Most of the published research on atrial fibrillation ( AF ) is limited to studies in the developed world and included mainly Caucasian patients . Data about women with AF among other ethnicities is very limited . OBJECTIVES The aim of this study was to compare the clinical characteristics , treatment and outcome of women to men hospitalized with AF in a middle-eastern country . METHODS Retrospective analysis of prospect i ve registry of all patients hospitalized with AF in Qatar from 1991 through 2010 was made . Clinical characteristics , management , and outcomes of AF patients were compared according to gender . RESULTS During the 20-years period ; 1417 women and 2432 men were hospitalized for AF . Women were 5 years older and more likely to have diabetes mellitus , hypertension , and chronic renal impairment and were also less likely to be current smokers and to have ischemic heart disease and impaired left ventricular function when compared to men . There was no gender preference in the use of anticoagulation . The prevalence of concomitant ischemic heart disease and hypertension increased , while the prevalence of valvular heart disease and heart failure decreased among patients hospitalized with AF over the study period . In-hospital mortality and stroke rates were comparable between the two groups . CONCLUSIONS Women hospitalized with atrial fibrillation were older in age and had higher prevalence of co-morbid cardiovascular risk factors compared to men whereas , mortality and stroke rates were comparable AIMS Women have an increased risk for atrial fibrillation (AF)-related complications and there is evidence towards a reduced efficacy of the rhythm control strategy than men . A catheter-based strategy is therefore widely attractive , but the impact of gender on catheter ablation ( CA ) of AF remains undefined . METHODS AND RESULTS We included 221 consecutive patients ( 150 men ) who underwent CA of drug-refractory AF .  Gender differences in clinical presentation and outcomes were compared . Women were older ( P = 0.002 ) , had a longer history of AF ( P = 0.04 ) , and were more likely to have hypertension ( P = 0.04 ) . Moreover , a concomitant valvular heart disease tended to be more common in women ( 32.4 vs. 23.3 % ; P = 0.28 ) and left atrium dimensions were significantly larger ( P = 0.003 ) . However , acute success rate and complications rate were similar between genders . After 22.5 + /- 11.8 months of follow-up , the overall freedom from arrhythmia recurrences was similar ( 83.1 vs. 82.7 % in men ) , and a similar improvement in SF-36 quality of life scores was achieved in both groups . CONCLUSION Women are referred for AF ablation later with a more complex clinical pre-operative presentation . Despite this higher risk profile in women , no differences were detected in clinical outcomes . Our findings indicate that CA of AF appears to be safe and effective in women as in men Background —Previous studies provide conflicting results about whether women are at higher risk than men for thromboembolism in the setting of atrial fibrillation ( AF ) . We examined data from a large contemporary cohort of AF patients to address this question . Methods and Results —We prospect ively studied 13 559 adults with AF and recorded data on patients ’ clinical characteristics and the occurrence of incident hospitalizations for ischemic stroke , peripheral embolism , and major hemorrhagic events through search ing vali date d computerized data bases and medical record review . We compared event rates by patient sex using multivariable log-linear regression , adjusting for clinical risk factors for stroke , and stratifying by warfarin use . We identified 394  ischemic stroke and peripheral embolic events during 15 494 person-years of follow-up off warfarin . After multivariable analysis , women had higher annual rates of thromboembolism off warfarin than did men ( 3.5 % versus 1.8 % ; adjusted rate ratio [ RR ] , 1.6 ; 95 % CI , 1.3 to 1.9 ) . There was no significant difference by sex in 30-day mortality after thromboembolism ( 23 % for both ) . Warfarin use was associated with significantly lower adjusted thromboembolism rates for both women and men ( RR , 0.4 ; 95 % CI , 0.3 to 0.5 ; and RR , 0.6 ; 95 % CI , 0.5 to 0.8 , respectively ) , with similar annual rates of major hemorrhage ( 1.0 % and 1.1 % , respectively ) . Conclusions —Women are at higher risk than men for AF-related thromboembolism off warfarin . Warfarin therapy appears be as effective in women , if not more so , than in men , with similar rates of major hemorrhage . Female sex is an independent risk factor for thromboembolism and should influence the decision to use anticoagulant therapy in persons with AF AIMS The risk of stroke is greater among women 
    Output:
    
agent
In brief , female atrial fibrillation patients more commonly present comorbidities , leading to a higher prevalence of persistent atrial fibrillation ; moreover , they refer to hospital care later and with a longer disease history .
Atrial fibrillation symptoms relate to low quality of life in female patients ; in fact , atrial fibrillation paroxysm usually presents higher heart rate , leading to preferentially adopt a rate rather than a rhythm-control strategy .
Female atrial fibrillation patients present an increased risk of stroke , worsened by the lower  oral anticoagulant prescription rate related to the concomitant higher haemorrhagic risk profile .
Trans-catheter ablation is under-used in female patients and , on the contrary , they are more commonly affected by anti-arrhythmic drug side effects
***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 Amiodarone use was associated with an increased need for pacemaker insertion in a retrospective study of patients with atrial fibrillation ( AF ) and prior myocardial infa rct ion . The aims of this study were to determine prospect ively whether amiodarone increases the need for pacemakers in a general population of patients with AF and whether this effect is modified by sex . METHODS The study included 1005 patients with new-onset AF who were enrolled in the Fibrillation Registry Assessing Costs , Therapies , Adverse events , and Lifestyle ( FRACTAL ) .  Multivariable Cox regression models , including time-dependent covariates accounting for medication exposure , were used to evaluate the risk of pacemaker insertion associated with amiodarone use . RESULTS Amiodarone use was associated with an increased risk of pacemaker insertion ( hazard ratio [ HR ] , 2.01 ; 95 % confidence interval [ CI ] , 1.08 - 3.76 ) after adjustment for age , sex , atrial flutter , coronary artery disease , heart failure , and hypertension . The effect of amiodarone use was modified by sex , with a significant risk in women but not in men ( HR , 4.69 ; 95 % CI , 1.99 - 11.05 vs HR , 1.05 ; 95 % CI , 0.42 - 2.58 [ P = .02 ] ) . This interaction remained significant after adjustment for weight , body mass index , weight-adjusted amiodarone dose , and use of other antiarrhythmic or rate control drugs . CONCLUSION The risk of bradyarrhythmia requiring pacemaker insertion associated with amiodarone use for AF is significantly greater in women than in men , independent of weight or body mass index Patients with atrial fibrillation ( AF ) report impaired health-related quality of life ( QOL ) . Differences between men and women with AF have not been described and personality attributes such as somatization ( tendency to amplify benign bodily sensations ) may mediate potential gender differences in QOL . Patients with AF ( n = 264 , 59 % men ) who participated in the Canadian Trial of Atrial Fibrillation ( n = 403 ) completed vali date d QOL question naires at baseline , 3 months , and 12 months after antiarrhythmic drug treatment .  Women were significantly older than men and a greater proportion had hypertension , but other cardiac variables did not differ between women and men . At baseline , after controlling for significant clinical and demographic factors , women reported worse physical health ( p = 0.002 ) and functional capacity ( p < 0.001 ) , but not mental health or general well-being . Women also had more frequent and severe cardiac symptoms than men ( both p < 0.001 ) . Physical health improved significantly from baseline to 3 months for women ( p = 0.002 ) , but not for men ( p = 0.066 ) . Conversely , mental health improved for men ( p = 0.007 ) , but not for women . Cardiac symptom frequency and severity improved over time for women and men ( all p < 0.001 ) . Tendency to somatize predicted poor QOL , and women had higher scores than men ( p = 0.023 ) . However , after controlling for somatization , women still had worse physical function , functional capacity , and symptom burden than men . Independent of cardiac disease severity and age , women with AF had significantly more impaired QOL than men , specifically on domains related to physical rather than emotional functioning . Personality attributes may have a role in influencing QOL outcomes BACKGROUND AND PURPOSE Nonvalvular atrial fibrillation ( AF ) is a strong , independent risk factor for stroke , but the absolute rate of stroke varies widely among AF patients , importantly influencing the potential benefit of antithrombotic prophylaxis . We explore factors associated with ischemic stroke in AF patients taking aspirin .  METHODS We performed multivariate logistic regression analysis of 2012 participants given aspirin alone or in combination with low , inefficacious doses of warfarin in the Stroke Prevention in Atrial Fibrillation I-III trials followed for a mean of 2.0 years , during which 130 ischemic strokes were observed . RESULTS Age ( relative risk [RR]=1.8 per decade , P<0.001 ) , female sex ( RR=1.6 , P=0.01 ) , history of hypertension ( RR=2.0 , P<0.001 ) , systolic blood pressure > 160 mm Hg ( RR=2.3 , P<0.001 ) , and prior stroke or transient ischemic attack ( RR=2.9 , P<0.001 ) were independently associated with increased stroke risk . Regular consumption of > /=14 alcohol-containing drinks per week was associated with reduced stroke risk ( adjusted RR=0.4 , P=0.04 ) . Among SPAF III participants , estrogen hormone replacement therapy was associated with a higher risk of ischemic stroke ( adjusted RR=3.2 , P=0.007 ) . With the use of these variables , a risk stratification scheme for primary prevention separated participants into those with high ( 7.1%/y , 22 % of the cohort ) , moderate ( 2.6%/y , 37 % of the cohort ) , and low ( 0.9%/y , 41 % of the cohort ) rates of stroke . Ischemic strokes in low-risk participants were less often disabling ( P<0.001 ) . CONCLUSIONS Patients with AF who have high and low rates of stroke during treatment with  aspirin can be identified . However , validation of our risk stratification scheme is necessary before it can be applied with confidence to clinical management . Postmenopausal estrogen replacement therapy and moderate alcohol consumption may additionally modify the risk of stroke in AF , but these findings require confirmation BACKGROUND Warfarin reduces the risk of stroke in patients with atrial fibrillation but increases the risk of hemorrhage and is difficult to use . Dabigatran is a new oral direct thrombin inhibitor . METHODS In this noninferiority trial , we r and omly assigned 18,113 patients who had atrial fibrillation and a risk of stroke to receive , in a blinded fashion , fixed doses of dabigatran--110 mg or 150 mg twice daily -- or , in an unblinded fashion , adjusted-dose warfarin . The median duration of the follow-up period was 2.0 years . The primary outcome was stroke or systemic embolism . RESULTS Rates of the primary outcome were 1.69 % per year in the warfarin group , as compared with 1.53 % per year in the group that received 110 mg of dabigatran ( relative risk with dabigatran , 0.91 ; 95 % confidence interval [ CI ] , 0.74 to 1.11 ; P<0.001 for noninferiority ) and 1.11 % per year in the group that received 150 mg of dabigatran ( relative risk , 0.66 ; 95 % CI , 0.53 to 0.82 ; P<0.001 for superiority ) . The rate of major bleeding was 3.36 % per year in the warfarin group , as compared with 2.71 % per year in the group receiving 110 mg of dabigatran ( P=0.003 ) and 3.11 % per year in the group receiving 150 mg of dabigatran ( P=0.31 ) . The rate of hemorrhagic stroke was 0.38 % per year in the warfarin group , as compared with 0.12 % per year with 110 mg of dabigatran ( P<0.001 ) and 0.10 % per year with 150 mg of dabigatran ( P<0.001 ) . The mortality rate was 4.13 % per year in the warfarin group , as compared with 3.75 % per year with 110 mg of dabigatran ( P=0.13 ) and 3.64 % per year with 150 mg of dabigatran ( P=0.051 ) . CONCLUSIONS In patients with atrial fibrillation , dabigatran given at a dose of 110 mg was associated with rates of stroke and systemic embolism that were similar to those associated with warfarin , as well as lower rates of major hemorrhage .  Dabigatran administered at a dose of 150 mg , as compared with warfarin , was associated with lower rates of stroke and systemic embolism but similar rates of major hemorrhage . ( Clinical Trials.gov number , NCT00262600 . BACKGROUND Most of the published research on atrial fibrillation ( AF ) is limited to studies in the developed world and included mainly Caucasian patients . Data about women with AF among other ethnicities is very limited . OBJECTIVES The aim of this study was to compare the clinical characteristics , treatment and outcome of women to men hospitalized with AF in a middle-eastern country . METHODS Retrospective analysis of prospect i ve registry of all patients hospitalized with AF in Qatar from 1991 through 2010 was made . Clinical characteristics , management , and outcomes of AF patients were compared according to gender . RESULTS During the 20-years period ; 1417 women and 2432 men were hospitalized for AF . Women were 5 years older and more likely to have diabetes mellitus , hypertension , and chronic renal impairment and were also less likely to be current smokers and to have ischemic heart disease and impaired left ventricular function when compared to men . There was no gender preference in the use of anticoagulation . The prevalence of concomitant ischemic heart disease and hypertension increased , while the prevalence of valvular heart disease and heart failure decreased among patients hospitalized with AF over the study period . In-hospital mortality and stroke rates were comparable between the two groups . CONCLUSIONS Women hospitalized with atrial fibrillation were older in age and had higher prevalence of co-morbid cardiovascular risk factors compared to men whereas , mortality and stroke rates were comparable AIMS Women have an increased risk for atrial fibrillation (AF)-related complications and there is evidence towards a reduced efficacy of the rhythm control strategy than men . A catheter-based strategy is therefore widely attractive , but the impact of gender on catheter ablation ( CA ) of AF remains undefined . METHODS AND RESULTS We included 221 consecutive patients ( 150 men ) who underwent CA of drug-refractory AF .  Gender differences in clinical presentation and outcomes were compared . Women were older ( P = 0.002 ) , had a longer history of AF ( P = 0.04 ) , and were more likely to have hypertension ( P = 0.04 ) . Moreover , a concomitant valvular heart disease tended to be more common in women ( 32.4 vs. 23.3 % ; P = 0.28 ) and left atrium dimensions were significantly larger ( P = 0.003 ) . However , acute success rate and complications rate were similar between genders . After 22.5 + /- 11.8 months of follow-up , the overall freedom from arrhythmia recurrences was similar ( 83.1 vs. 82.7 % in men ) , and a similar improvement in SF-36 quality of life scores was achieved in both groups . CONCLUSION Women are referred for AF ablation later with a more complex clinical pre-operative presentation . Despite this higher risk profile in women , no differences were detected in clinical outcomes . Our findings indicate that CA of AF appears to be safe and effective in women as in men Background —Previous studies provide conflicting results about whether women are at higher risk than men for thromboembolism in the setting of atrial fibrillation ( AF ) . We examined data from a large contemporary cohort of AF patients to address this question . Methods and Results —We prospect ively studied 13 559 adults with AF and recorded data on patients ’ clinical characteristics and the occurrence of incident hospitalizations for ischemic stroke , peripheral embolism , and major hemorrhagic events through search ing vali date d computerized data bases and medical record review . We compared event rates by patient sex using multivariable log-linear regression , adjusting for clinical risk factors for stroke , and stratifying by warfarin use . We identified 394  ischemic stroke and peripheral embolic events during 15 494 person-years of follow-up off warfarin . After multivariable analysis , women had higher annual rates of thromboembolism off warfarin than did men ( 3.5 % versus 1.8 % ; adjusted rate ratio [ RR ] , 1.6 ; 95 % CI , 1.3 to 1.9 ) . There was no significant difference by sex in 30-day mortality after thromboembolism ( 23 % for both ) . Warfarin use was associated with significantly lower adjusted thromboembolism rates for both women and men ( RR , 0.4 ; 95 % CI , 0.3 to 0.5 ; and RR , 0.6 ; 95 % CI , 0.5 to 0.8 , respectively ) , with similar annual rates of major hemorrhage ( 1.0 % and 1.1 % , respectively ) . Conclusions —Women are at higher risk than men for AF-related thromboembolism off warfarin . Warfarin therapy appears be as effective in women , if not more so , than in men , with similar rates of major hemorrhage . Female sex is an independent risk factor for thromboembolism and should influence the decision to use anticoagulant therapy in persons with AF AIMS The risk of stroke is greater among women 
    Output:
    