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 — Data regarding the long-term efficacy of atrial fibrillation ( AF ) ablation are still lacking . Methods and Results —Two hundred four consecutive patients symptomatic for paroxysmal or persistent/permanent AF were r and omly assigned to 2 different ablation schemes : pulmonary vein isolation ( PVI ) and PVI plus left linear lesions ( LL ) . Primary end point was to assess the maintenance of sinus rhythm ( SR ) after procedures 1 and 2 in the absence of antiarrhythmic drugs in a long-term follow-up of at least 3 years . Paroxysmal AF — With a single procedure at 12-month follow-up , 46 % of patients treated with PVI maintained SR , whereas at 3-year follow-up , 29 % were in SR ; using the “ PVI plus LL ” at the 12-month follow-up , 57 % of patients were in SR , whereas at the 3-year follow-up , 53 % remained in SR . After a second procedure , the long-term overall success rate without antiarrhythmic drugs was 62 % with PVI and 85 % with PVI plus LL . Persistent/Permanent AF — With a single procedure at the 12-month follow-up , 27 % of patients treated with PVI were in SR , whereas at the 3-year follow-up , 19 % maintained SR ; using the PVI plus LL with a single procedure at the 12-month follow-up 45 % of patients were in SR , whereas at the 3-year follow-up , 41 % remained in SR . After a second procedure , the long-term overall success rate without antiarrhythmic drugs was 39 % with PVI and 75 % with PVI plus LL . Conclusions —A long-term follow-up of AF ablation shows that short-term results can not be considered permanent because AF recurrences are still present after the first year especially in patients who have had “ PVI ” strategy .  PVI isolation plus LL is superior to the PVI strategy in maintaining SR without antiarrhythmic drugs after procedures 1 and 2 both in paroxysmal and persistent AF Background — Information on comparative outcome between radiofrequency catheter ablation ( RFA ) and antiarrhythmic drugs ( AADs ) > 1 year after r and omization is important for clinical decision-making . Methods and Results — A total of 198 patients ( age , 56±10 years ) with paroxysmal atrial fibrillation were r and omly assigned to RFA ( 99 patients ) or to AADs ( 99 patients ) . We evaluated efficacy of RFA or AADs in a comparable 48-month follow-up period according to intention-to-treat analysis . Cardiac rhythm was assessed with daily transtelephonic transmissions . Quality of life was also analyzed . At 4 years , among the 99 patients first assigned to RFA , the procedure was repeated because of recurrent atrial fibrillation/atrial tachycardia in 27 patients ( 27.3 % ) . Among the 99 patients r and omly assigned to AADs , 87 ( 87.9 % ) crossed over to undergo RFA and 4 years after r and om assignment only 12 ( 12.1 % ) were in sinus rhythm with AAD alone without ablation . Despite the high level of crossovers , at 4 years the intention-to-treat analysis showed that 72.7 % of patients in the ablation arm and 56.5 % of those initially r and omly assigned to AADs were free of recurrent atrial fibrillation/atrial tachycardia ( P=0.017 ) . During the follow-up , 19.2 % of AAD patients progressed to persistent atrial fibrillation before switching to RFA . RFA significantly improved quality of life ( P<0.001 ) , whereas before crossing over to RFA , patients receiving AADs showed poorer quality of life . Except for new left atrial tachycardia , there were no serious complications caused by RFA . Conclusions — With follow-up extended to 4 years after r and omly assigned , ablation remains superior to antiarrhythmic drug in these patients with paroxysmal atrial fibrillation . Clinical Trial Registration — URL : http://www . clinical trials.gov . Unique identifier : NCT00340314 OBJECTIVES The purpose of this study was to investigate long-term outcomes of freedom from atrial fibrillation ( AF ) after pulmonary vein ( PV ) isolation using cryoballoon ablation with balloon-size selection based on individual PV diameters . BACKGROUND Data are lacking on long-term outcomes from cryoablation and on the most effective balloon size . METHODS This was a prospect i ve observational study involving 605 consecutively enrolled patients with symptomatic paroxysmal AF ( n = 579 ) or persistent AF .  Cryoballoon size was based on magnetic resonance imaging and /or conventional angiograms . Patients were followed up every 3 months during the first year after discharge and every 6 months in the second year . After 24 months , follow-up was on an outpatient basis with documented AF episodes recorded . RESULTS The PV isolation was achieved without touch-up in 91.1 % of patients , using the smaller balloon in 26.7 % , the larger balloon in 25.6 % , and both balloons in 47.7 % of patients . Follow-up data for > 12 months ( median 30 months ; interquartile range 18 to 48 months ) were available for 451 patients , 278 ( 61.6 % ) of whom were free of AF recurrence with no need for repeat procedures after the 3-month blanking period . Rates of freedom from AF after 1 , 2 , and 3 repeat procedures ( using cryoballoon or radiofrequency ablation with similar success rates ) were 74.9 % , 76.2 % , and 76.9 % , respectively . Use of the smaller balloons or both balloons produced the highest rates of long-term freedom from AF . Phrenic nerve palsy occurred in 12 patients ( 2 % ) , resolving within 3 to 9 months . CONCLUSIONS Rates of long-term freedom from AF after cryoballoon ablation are similar to those reported for radiofrequency ablation . A choice between balloons may improve outcomes AIMS The Atrial Fibrillation Ablation Pilot Study is a prospect i ve registry design ed to describe the clinical epidemiology of patients undergoing an atrial fibrillation ( AFib ) ablation  , and the diagnostic/therapeutic processes applied across Europe . The aims of the 1-year follow-up were to analyse how centres assess in routine clinical practice the success of the procedure and to evaluate the success rate and long-term safety/complications . METHODS AND RESULTS Seventy-two centres in 10 European countries were asked to enrol 20 consecutive patients undergoing a first AFib ablation procedure .  A web-based case report form captured information on pre-procedural , procedural , and 1-year follow-up data . Between October 2010 and May 2011 , 1410 patients were included and 1391 underwent an AFib ablation ( 98.7 % ) . A total of 1300 patients ( 93.5 % ) completed a follow-up control 367 ± 42 days after the procedure . Arrhythmia documentation was done by an  electrocardiogram  in 76 % ,  Holter-monitoring  in 52 % ,  transtelephonic monitoring in 8 % , and /or implanted systems in 4.5 % . Over 50 % became asymptomatic . Twenty-one per cent were re-admitted due to post-ablation arrhythmias . Success without antiarrhythmic drugs was achieved in 40.7 % of patients ( 43.7 % in paroxysmal AF ; 30.2 % in persistent AF ; 36.7 % in long-lasting persistent AF ) . A second ablation was required in 18 % of the cases and 43.4 % were under antiarrhythmic treatment . Thirty-three patients ( 2.5 % ) suffered an adverse event , 272 ( 21 % ) experienced a left atrial tachycardia , and 4 patients died ( 1 haemorrhagic stroke , 1 ventricular fibrillation in a patient with ischaemic heart disease , 1 cancer , and 1 of unknown cause ) . CONCLUSION The AFib Ablation Pilot Study provided crucial information on the epidemiology , management , and outcomes of catheter ablation of AFib in a real-world setting . The methods used to assess the success of the procedure appeared at least suboptimal . Even in this context , the 12-month success rate appears to be somewhat lower to the one reported clinical trials AIMS Pioglitazone , one of the peroxisome proliferator-activated receptor-gamma activators , possesses anti-inflammatory and antioxidant properties . In the present study , we sought to identify the impact of pioglitazone on the outcome of catheter ablation for paroxysmal atrial fibrillation ( PAF ) . METHODS AND RESULTS We conducted a prospect i ve observational cohort study of 150 consecutive patients undergoing catheter ablation of drug-refractory PAF . All patients had a history of type 2 diabetes mellitus ( T2DM ) and were divided based on whether they received pioglitazone before ablation or not . After grouping , 51 patients treated with pioglitazone  and 99 control subjects were followed up at least 15 months after ablation . After a single ablation , sinus rhythm was maintained in 44 patients ( 86.3 % ) of the pioglitazone group vs. 70 patients ( 70.7 % ) of the control group ( P = 0.034 ) without antiarrhythmic drug during a mean follow-up of 22.9 ± 5.1 months . The second ablation was performed in 5 patients ( 9.8 % ) from the pioglitazone group and in 24 patients ( 24.2 % ) from the control group ( P = 0.034 ) . Multivariate logistic analysis showed left atrium diameter was associated with a high risk of atrial tachyarrhythmias recurrence , and treatment with renin-angiotensin system inhibitor as well as pioglitazone was associated with a reduced atrial tachyarrhythmias recurrence rate . CONCLUSION Pioglitazone improved the preservation of sinus rhythm and reduced the reablation rate in patients with PAF and T2DM after catheter ablation OBJECTIVES This study was design ed to investigate the potential of circumferential pulmonary vein ( PV ) ablation for atrial fibrillation ( AF ) to maintain sinus rhythm ( SR ) over time , thus reducing mortality and morbidity while enhancing quality of life ( QoL ) . BACKGROUND Circumferential PV ablation is safe and effective , but the long-term outcomes and its impact on QoL have not been assessed or compared with those for medical therapy . METHODS We examined the clinical course of 1,171 consecutive patients with symptomatic AF who were referred to us between January 1998 and March 2001 . The 589 ablated patients were compared with the 582 who received antiarrhythmic medications for SR control . The QoL of 109 ablated and 102 medically treated patients was measured with the SF-36 survey . RESULTS Median follow-up was 900 days ( range 161 to 1,508 days ) . Kaplan-Meier analysis showed observed survival for ablated patients was longer than among patients treated medically ( p < 0.001 ) , and not different from that expected for healthy persons of the same gender and calendar year of birth ( p = 0.55 ) . Cox proportional-hazards model revealed in the ablation group hazard ratios of 0.46 ( 95 % confidence interval [ CI ] , 0.31 to 0.68 ; p < 0.001 ) for all-cause mortality , of 0.45 ( 95 % CI , 0.31 to 0.64 ; p < 0.001 ) for morbidities mainly due to heart failure and ischemic cerebrovascular events , and of 0.30 ( 95 % CI , 0.24 to 0.37 ; p < 0.001 ) for AF recurrence . Ablated patients ' QoL , different from patients treated medically , reached normative levels at six months and remained unchanged at one year . CONCLUSIONS Pulmonary vein ablation improves mortality , morbidity , and QoL as compared with medical therapy . Our findings pave the way for r and omized trials to prospect a wider application of ablation therapy for AF INTRODUCTION Atrial fibrillation ( AF ) and diabetes mellitus type 2 ( DM2 ) often coexist ; however , a small number of patients with DM2 undergoing catheter ablation ( CA ) of AF  have been included in previous studies . The aim of this study was to evaluate safety and efficacy of ablation therapy in DM2 patients with drug refractory AF . METHODS AND RESULTS From January 2005 to September 2006 , 70 patients with a diagnosis of DM2 and paroxysmal ( n = 29 ) or persistent ( n = 41 ) AF were r and omized to receive either pulmonary vein isolation or a new antiarrhythmic drug treatment ( ADT ) with a 1-year follow-up . The primary endpoint was the time to first AF recurrence . By Kaplan-Meier analysis , at the end of follow-up , 42.9 % of patients in the ADT group and 80 % of patients who received a single ablation procedure and were without medications were free of AF ( P = 0.001 ) . In the ablation group , a significant improvement in quality -of-life ( Qo 
    Output:
    
agent
Catheter ablation of AF  safety and efficacy in DM patients is similar to general population , especially when performed in younger patients with satisfactory glycemic control .
Catheter ablation of AF reduces the amount of patients requiring AADs , an additional benefit in this population commonly exposed to adverse effects of AF pharmacological treatments
***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 — Data regarding the long-term efficacy of atrial fibrillation ( AF ) ablation are still lacking . Methods and Results —Two hundred four consecutive patients symptomatic for paroxysmal or persistent/permanent AF were r and omly assigned to 2 different ablation schemes : pulmonary vein isolation ( PVI ) and PVI plus left linear lesions ( LL ) . Primary end point was to assess the maintenance of sinus rhythm ( SR ) after procedures 1 and 2 in the absence of antiarrhythmic drugs in a long-term follow-up of at least 3 years . Paroxysmal AF — With a single procedure at 12-month follow-up , 46 % of patients treated with PVI maintained SR , whereas at 3-year follow-up , 29 % were in SR ; using the “ PVI plus LL ” at the 12-month follow-up , 57 % of patients were in SR , whereas at the 3-year follow-up , 53 % remained in SR . After a second procedure , the long-term overall success rate without antiarrhythmic drugs was 62 % with PVI and 85 % with PVI plus LL . Persistent/Permanent AF — With a single procedure at the 12-month follow-up , 27 % of patients treated with PVI were in SR , whereas at the 3-year follow-up , 19 % maintained SR ; using the PVI plus LL with a single procedure at the 12-month follow-up 45 % of patients were in SR , whereas at the 3-year follow-up , 41 % remained in SR . After a second procedure , the long-term overall success rate without antiarrhythmic drugs was 39 % with PVI and 75 % with PVI plus LL . Conclusions —A long-term follow-up of AF ablation shows that short-term results can not be considered permanent because AF recurrences are still present after the first year especially in patients who have had “ PVI ” strategy .  PVI isolation plus LL is superior to the PVI strategy in maintaining SR without antiarrhythmic drugs after procedures 1 and 2 both in paroxysmal and persistent AF Background — Information on comparative outcome between radiofrequency catheter ablation ( RFA ) and antiarrhythmic drugs ( AADs ) > 1 year after r and omization is important for clinical decision-making . Methods and Results — A total of 198 patients ( age , 56±10 years ) with paroxysmal atrial fibrillation were r and omly assigned to RFA ( 99 patients ) or to AADs ( 99 patients ) . We evaluated efficacy of RFA or AADs in a comparable 48-month follow-up period according to intention-to-treat analysis . Cardiac rhythm was assessed with daily transtelephonic transmissions . Quality of life was also analyzed . At 4 years , among the 99 patients first assigned to RFA , the procedure was repeated because of recurrent atrial fibrillation/atrial tachycardia in 27 patients ( 27.3 % ) . Among the 99 patients r and omly assigned to AADs , 87 ( 87.9 % ) crossed over to undergo RFA and 4 years after r and om assignment only 12 ( 12.1 % ) were in sinus rhythm with AAD alone without ablation . Despite the high level of crossovers , at 4 years the intention-to-treat analysis showed that 72.7 % of patients in the ablation arm and 56.5 % of those initially r and omly assigned to AADs were free of recurrent atrial fibrillation/atrial tachycardia ( P=0.017 ) . During the follow-up , 19.2 % of AAD patients progressed to persistent atrial fibrillation before switching to RFA . RFA significantly improved quality of life ( P<0.001 ) , whereas before crossing over to RFA , patients receiving AADs showed poorer quality of life . Except for new left atrial tachycardia , there were no serious complications caused by RFA . Conclusions — With follow-up extended to 4 years after r and omly assigned , ablation remains superior to antiarrhythmic drug in these patients with paroxysmal atrial fibrillation . Clinical Trial Registration — URL : http://www . clinical trials.gov . Unique identifier : NCT00340314 OBJECTIVES The purpose of this study was to investigate long-term outcomes of freedom from atrial fibrillation ( AF ) after pulmonary vein ( PV ) isolation using cryoballoon ablation with balloon-size selection based on individual PV diameters . BACKGROUND Data are lacking on long-term outcomes from cryoablation and on the most effective balloon size . METHODS This was a prospect i ve observational study involving 605 consecutively enrolled patients with symptomatic paroxysmal AF ( n = 579 ) or persistent AF .  Cryoballoon size was based on magnetic resonance imaging and /or conventional angiograms . Patients were followed up every 3 months during the first year after discharge and every 6 months in the second year . After 24 months , follow-up was on an outpatient basis with documented AF episodes recorded . RESULTS The PV isolation was achieved without touch-up in 91.1 % of patients , using the smaller balloon in 26.7 % , the larger balloon in 25.6 % , and both balloons in 47.7 % of patients . Follow-up data for > 12 months ( median 30 months ; interquartile range 18 to 48 months ) were available for 451 patients , 278 ( 61.6 % ) of whom were free of AF recurrence with no need for repeat procedures after the 3-month blanking period . Rates of freedom from AF after 1 , 2 , and 3 repeat procedures ( using cryoballoon or radiofrequency ablation with similar success rates ) were 74.9 % , 76.2 % , and 76.9 % , respectively . Use of the smaller balloons or both balloons produced the highest rates of long-term freedom from AF . Phrenic nerve palsy occurred in 12 patients ( 2 % ) , resolving within 3 to 9 months . CONCLUSIONS Rates of long-term freedom from AF after cryoballoon ablation are similar to those reported for radiofrequency ablation . A choice between balloons may improve outcomes AIMS The Atrial Fibrillation Ablation Pilot Study is a prospect i ve registry design ed to describe the clinical epidemiology of patients undergoing an atrial fibrillation ( AFib ) ablation  , and the diagnostic/therapeutic processes applied across Europe . The aims of the 1-year follow-up were to analyse how centres assess in routine clinical practice the success of the procedure and to evaluate the success rate and long-term safety/complications . METHODS AND RESULTS Seventy-two centres in 10 European countries were asked to enrol 20 consecutive patients undergoing a first AFib ablation procedure .  A web-based case report form captured information on pre-procedural , procedural , and 1-year follow-up data . Between October 2010 and May 2011 , 1410 patients were included and 1391 underwent an AFib ablation ( 98.7 % ) . A total of 1300 patients ( 93.5 % ) completed a follow-up control 367 ± 42 days after the procedure . Arrhythmia documentation was done by an  electrocardiogram  in 76 % ,  Holter-monitoring  in 52 % ,  transtelephonic monitoring in 8 % , and /or implanted systems in 4.5 % . Over 50 % became asymptomatic . Twenty-one per cent were re-admitted due to post-ablation arrhythmias . Success without antiarrhythmic drugs was achieved in 40.7 % of patients ( 43.7 % in paroxysmal AF ; 30.2 % in persistent AF ; 36.7 % in long-lasting persistent AF ) . A second ablation was required in 18 % of the cases and 43.4 % were under antiarrhythmic treatment . Thirty-three patients ( 2.5 % ) suffered an adverse event , 272 ( 21 % ) experienced a left atrial tachycardia , and 4 patients died ( 1 haemorrhagic stroke , 1 ventricular fibrillation in a patient with ischaemic heart disease , 1 cancer , and 1 of unknown cause ) . CONCLUSION The AFib Ablation Pilot Study provided crucial information on the epidemiology , management , and outcomes of catheter ablation of AFib in a real-world setting . The methods used to assess the success of the procedure appeared at least suboptimal . Even in this context , the 12-month success rate appears to be somewhat lower to the one reported clinical trials AIMS Pioglitazone , one of the peroxisome proliferator-activated receptor-gamma activators , possesses anti-inflammatory and antioxidant properties . In the present study , we sought to identify the impact of pioglitazone on the outcome of catheter ablation for paroxysmal atrial fibrillation ( PAF ) . METHODS AND RESULTS We conducted a prospect i ve observational cohort study of 150 consecutive patients undergoing catheter ablation of drug-refractory PAF . All patients had a history of type 2 diabetes mellitus ( T2DM ) and were divided based on whether they received pioglitazone before ablation or not . After grouping , 51 patients treated with pioglitazone  and 99 control subjects were followed up at least 15 months after ablation . After a single ablation , sinus rhythm was maintained in 44 patients ( 86.3 % ) of the pioglitazone group vs. 70 patients ( 70.7 % ) of the control group ( P = 0.034 ) without antiarrhythmic drug during a mean follow-up of 22.9 ± 5.1 months . The second ablation was performed in 5 patients ( 9.8 % ) from the pioglitazone group and in 24 patients ( 24.2 % ) from the control group ( P = 0.034 ) . Multivariate logistic analysis showed left atrium diameter was associated with a high risk of atrial tachyarrhythmias recurrence , and treatment with renin-angiotensin system inhibitor as well as pioglitazone was associated with a reduced atrial tachyarrhythmias recurrence rate . CONCLUSION Pioglitazone improved the preservation of sinus rhythm and reduced the reablation rate in patients with PAF and T2DM after catheter ablation OBJECTIVES This study was design ed to investigate the potential of circumferential pulmonary vein ( PV ) ablation for atrial fibrillation ( AF ) to maintain sinus rhythm ( SR ) over time , thus reducing mortality and morbidity while enhancing quality of life ( QoL ) . BACKGROUND Circumferential PV ablation is safe and effective , but the long-term outcomes and its impact on QoL have not been assessed or compared with those for medical therapy . METHODS We examined the clinical course of 1,171 consecutive patients with symptomatic AF who were referred to us between January 1998 and March 2001 . The 589 ablated patients were compared with the 582 who received antiarrhythmic medications for SR control . The QoL of 109 ablated and 102 medically treated patients was measured with the SF-36 survey . RESULTS Median follow-up was 900 days ( range 161 to 1,508 days ) . Kaplan-Meier analysis showed observed survival for ablated patients was longer than among patients treated medically ( p < 0.001 ) , and not different from that expected for healthy persons of the same gender and calendar year of birth ( p = 0.55 ) . Cox proportional-hazards model revealed in the ablation group hazard ratios of 0.46 ( 95 % confidence interval [ CI ] , 0.31 to 0.68 ; p < 0.001 ) for all-cause mortality , of 0.45 ( 95 % CI , 0.31 to 0.64 ; p < 0.001 ) for morbidities mainly due to heart failure and ischemic cerebrovascular events , and of 0.30 ( 95 % CI , 0.24 to 0.37 ; p < 0.001 ) for AF recurrence . Ablated patients ' QoL , different from patients treated medically , reached normative levels at six months and remained unchanged at one year . CONCLUSIONS Pulmonary vein ablation improves mortality , morbidity , and QoL as compared with medical therapy . Our findings pave the way for r and omized trials to prospect a wider application of ablation therapy for AF INTRODUCTION Atrial fibrillation ( AF ) and diabetes mellitus type 2 ( DM2 ) often coexist ; however , a small number of patients with DM2 undergoing catheter ablation ( CA ) of AF  have been included in previous studies . The aim of this study was to evaluate safety and efficacy of ablation therapy in DM2 patients with drug refractory AF . METHODS AND RESULTS From January 2005 to September 2006 , 70 patients with a diagnosis of DM2 and paroxysmal ( n = 29 ) or persistent ( n = 41 ) AF were r and omized to receive either pulmonary vein isolation or a new antiarrhythmic drug treatment ( ADT ) with a 1-year follow-up . The primary endpoint was the time to first AF recurrence . By Kaplan-Meier analysis , at the end of follow-up , 42.9 % of patients in the ADT group and 80 % of patients who received a single ablation procedure and were without medications were free of AF ( P = 0.001 ) . In the ablation group , a significant improvement in quality -of-life ( Qo 
    Output:
    