***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: AIMS Patients with atrial flutter are believed to be at lower risk of thromboembolism than patients with atrial fibrillation . However , the incidence of atrial thrombi and the need for anticoagulation in patients with atrial flutter is not well established . METHODS AND RESULTS A prospect i ve observational multicentre study was undertaken to assess the frequency of atrial thrombi and spontaneous echocontrast and the prevalence for aortic complex atherosclerotic lesions in a cohort of unselected patients with atrial flutter . We evaluated 134 patients ( 102 male , aged 70+/-9 years ) ; exclusion criteria were history of atrial fibrillation , rheumatic mitral valve disease and mitral mechanical prosthesis . The median of atrial flutter duration was 33 days . Twelve patients had been taking warfarin for more than 7 days . One hundred and twenty-four patients ( 94 % ) underwent a transoesophageal echocardiogram , which revealed left atrial appendage thrombi in two patients ( 1.6 % ) and right atrial thrombi in one patient ( 1 % ) . At least moderate left atrial echocontrast was found in 16/124 patients ( 13 % ) . Complex atherosclerotic aortic plaques were detected in 10 patients ( 8 % ) . Atrial flutter conversion was attempted in 93/134 patients ( 69 % ) . At the 1-month follow-up , two patients experienced a thromboembolic event following restoration of sinus rhythm . CONCLUSIONS Atrial thrombi and echocontrast , and complex aortic atherosclerotic plaques are relatively uncommon in patients with atrial flutter . Post-cardioversion embolism was observed in two patients in our study population ACCF : American College of Cardiology Foundation ACCP : American College of Chest Physicians ACS : acute coronary syndrome ACT : Atrial arrhythmia Conversion Trial ADONIS : American – Australian – African trial with DronedarONe In atrial fibrillation or flutter for the maintenance of Sinus rhythm AF : atrial fibrillation AHA : American Heart Association AND ROMEDA : ANtiarrhythmic trial with DROnedarone in Moderate-to-severe congestive heart failure Evaluating morbidity DecreAse APHRS : Asia Pacific Heart Rhythm Society aPTT : activated partial thromboplastin time ARB : angiotensin-receptor blocker ARISTOTLE : Apixaban for Reduction In STroke and Other ThromboemboLic Events in atrial fibrillation ATHENA : A placebo-controlled , double-blind , parallel arm Trial to assess the efficacy of dronedarone 400 mg b.i.d . for the prevention of cardiovascular Hospitalization or death from any cause in patiENts with Atrial fibrillation/atrial flutter ATRIA : AnTicoagulation and Risk factors In Atrial fibrillation AVERROES : Apixaban VErsus acetylsalicylic acid ( ASA ) to Reduce the Rate Of Embolic Stroke in atrial fibrillation patients who have failed or are unsuitable for vitamin K antagonist treatment AVRO : A prospect i ve , r and omized , double-blind , Active-controlled , superiority study of Vernakalant vs. amiodarone in Recent Onset atrial fibrillation b.i.d : bis in die ( twice daily ) b.p.m . : beats per minute CABANA : Catheter ABlation vs . ANtiarrhythmic drug therapy for Atrial fibrillation CABG : coronary artery bypass graft CAP : Continued Access to Protect AF CHA2DS2-VASc : Congestive heart failure or left ventricular dysfunction Hypertension , Age ≥75 ( doubled ) , Diabetes , Stroke (doubled)-Vascular disease , Age 65–74 , Sex category ( female ) CHADS2 : Congestive heart failure , Hypertension , Age ≥75 , Diabetes , Stroke ( doubled ) CI : confidence interval CRAFT : Controlled R and omized Atrial Fibrillation Trial CrCl : creatinine clearance DAFNE : Dronedarone Atrial FibrillatioN study after Electrical cardioversion DIONYSOS : R and omized Double blind trIal to evaluate efficacy and safety of drOnedarone ( 400 mg b.i.d . ) vs . amiodaroNe ( 600 mg q.d . for 28 daYS , then 200 mg qd thereafter ) for at least 6 mOnths for the maintenance of Sinus rhythm in patients with atrial fibrillation EAST : Early treatment of Atrial fibrillation for Stroke prevention Trial EHRA : European Heart Rhythm Association ECG : electrocardiogram EMA : European Medicines Agency ERATO : Efficacy and safety of dRonedArone for The cOntrol of ventricular rate during atrial fibrillation EURIDIS : EURopean trial In atrial fibrillation or flutter patients receiving Dronedarone for the maIntenance of Sinus rhythm FAST : atrial Fibrillation catheter Ablation vs . Surgical ablation Treatment FDA : Food and Drug Administration Flec-SL : Flecainide Short-Long trial HAS-BLED : Hypertension , Abnormal renal/liver function , Stroke , Bleeding history or predisposition , Labile INR , Elderly , Drugs/alcohol concomitantly HF-PEF : heart failure with preserved ejection fraction HF-REF : heart failure with reduced ejection fraction HR : hazard ratio HRS : Heart Rhythm Society ICH : intracranial haemorrhage INR : international normalized ratio i.v . : intravenous J-RHYTHM : Japanese RHYTHM management trial for atrial fibrillation LAA : left atrial appendage LoE : level of evidence LVEF : left ventricular ejection fraction MANTRA-PAF : Medical ANtiarrhythmic Treatment or Radiofrequency Ablation in Paroxysmal Atrial Fibrillation NICE : National Institute for Health and Clinical Excellence NOAC : novel oral anticoagulant NSAID : non-steroidal anti-inflammatory drug NYHA : New York Heart Association OAC : oral anticoagulant or oral anticoagulation o.d . : omni die ( every day ) PALLAS : Permanent Atrial fibriLLAtion outcome Study using dronedarone on top of st and ard therapy PCI : percutaneous coronary intervention PREVAIL : Prospect i ve R and omized EVAluation of the LAA closure device In patients with atrial fibrillation v s. Long-term warfarin therapy PROTECT AF : WATCHMAN LAA system for embolic PROTECTion in patients with Atrial Fibrillation PT : prothrombin time RAAFT : Radio frequency Ablation Atrial Fibrillation Trial RE-LY : R and omized Evaluation of Long-term anticoagulant therapY with dabigatran etexilate ROCKET-AF : Rivaroxaban Once daily oral direct factor Xa inhibition Compared with vitamin K antagonism for prevention of stroke and Embolism Trial in atrial fibrillation RRR : relative risk reduction TE : thromboembolism TIA : transient ischaemic attack t.i.d . : ter in die ( three times daily ) TOE : transoesophageal echocardiogram TTR : time in therapeutic range VKA : vitamin K antagonist Guidelines summarize and evaluate all currently available evidence on a particular issue with the aim of assisting physicians in selecting the best management strategy for an individual patient suffering from a given condition , taking into account the impact on AIMS We investigated the temporal changes in circulating levels of markers of extracellular cardiac matrix ( ECCM ) turnover and their relationship with infa rct size ( IS ) , ejection fraction ( EF ) , and left ventricular ( LV ) volumes , determined by serial cardiac magnetic resonance ( CMR ) imaging in patients with first-time ST-elevation myocardial infa rct ion ( STEMI ) . METHODS AND RESULTS Forty-two patients with a first-time STEMI , successfully revascularized by primary percutaneous coronary intervention ( pPCI ) had serum sample s taken prior to pPCI , 2 , 7 days , 2 months , and 1 year following STEMI for the analysis of the markers of collagen synthesis , and collagen degradation . Late enhancement and cine CMR was performed on Days 2 , 7 , 2 months , and 1-year post-STEMI . There was a significant increase in type I collagen degradation following STEMI that was not accompanied by an increase in collagen type I synthesis until 2 months and 1 year . In contrast to the delay in type I collagen synthesis , there was an immediate increase in type III collagen synthesis that was sustained for 1 year . N-terminal procollagen type I levels assessed prior to pPCI were predictive of adverse LV remodelling at all CMR time-points . CONCLUSIONS Our findings indicate a net type I collagen breakdown in the first week following STEMI compensated by an early increase in collagen type III synthesis . There is an increase in both type I and III collagen synthesis markers at 2 months and 1 year , indicating a persistent increase in collagen turnover even in these apparently successfully treated patients AIMS Primary percutaneous coronary intervention ( PCI ) is the preferred treatment for ST-elevation myocardial infa rct ion ( STEMI ) . The distance to primary PCI centres and the inherent time delay in delivering primary PCI , however , limit widespread use of this treatment . This study aim ed to evaluate the impact of pre-hospital diagnosis on time from emergency medical services contact to balloon inflation  ( system delay ) in an unselected cohort of patients with STEMI recruited from a large geographical area comprising both urban and rural districts . METHODS AND RESULTS From February 2004 until January 2007 , data on pre-hospital timing and transport distance were prospect ively recorded . Patients were divided into groups depending on achievement of pre-hospital diagnosis and /or direct referral to a primary PCI centre . Seven hundred and fifty-nine consecutive STEMI patients were included . In patients with a pre-hospital diagnosis and direct referral , the system delay was 92 vs. 153 min in patients without pre-hospital diagnosis ( P < 0.001 ) . Patients from rural areas were transported a median of 30 km longer than patients from urban areas ; however , this prolonged the system delay by only 9 min . CONCLUSION Pre-hospital electrocardiographic ( ECG ) diagnosis and direct referral for primary PCI enables STEMI patients living far from a PCI centre to achieve a system delay comparable with patients living in close vicinity of a PCI centre AIMS TOTAL ( N = 10 732 ) , a r and omized trial of routine manual thrombectomy vs. percutaneous coronary intervention alone  in ST elevation myocardial infa rct ion , showed no difference in the primary efficacy outcome but a significant increase in stroke . We sought to underst and these findings . METHODS AND RESULTS A detailed analysis of stroke timing , stroke severity , and stroke subtype was performed . Strokes were adjudicated by neurologists blinded to treatment assignment . Stroke within 30 days , the primary safety outcome , was increased [ 33 ( 0.7 % ) vs. 16 ( 0.3 % ) , hazard ratio ( HR ) 2.06 ; 95 % confidence interval ( CI ) 1.13 - 3.75 ] . The difference in stroke was apparent within 48 h [ 15 ( 0.3 % ) vs. 5 ( 0.1 % ) , HR 3.00 ; 95 % CI 1.09 - 8.25 ] . There was an increase in strokes within 180 days with minor or no disability ( Rankin 0 - 2 ) [ 18 ( 0.4 % ) vs. 13 ( 0.3 % ) HR 1.38 ; 95 % CI 0.68 - 2.82 ] and in strokes with major disability or fatal ( Rankin 3 - 6 ) [ 35 ( 0.7 % ) vs. 13 ( 0.3 % ) , HR 2.69 ; 95 % CI 1.42 - 5.08 ] . Most of the absolute difference was due to an increase in ischaemic strokes within 180 days [ 37 ( 0.7 % ) vs. 21 ( 0.4 % ) , HR 1.71 ; 95 % CI 1.03 - 3.00 ] , but there was also an increase in haemorrhagic strokes [ 10 ( 0.2 % ) vs. 2 ( 0.04 % ) , HR 4.98 ; 95 % CI 1.09 - 22.7 ] . Patients that had a stroke had a mortality of 30.8 % within 180 days vs. 3.4 % without a stroke ( P < 0.001 ) . A meta- analysis of r and omized trials ( N = 21 173 ) showed an increase in risk of stroke ( odds ratio 1.59 ; 95 % CI 1.11 - 2.27 ) but a trend towards reduction in mortality odds ratio ( odds ratio 0.87 ; 95 % CI 0.76 - 1.00 ) . CONCLUSION Thrombectomy was associated with a significant increase in stroke . Based on these findings , future trials must carefully collect stroke to determine safety in addition to efficacy The prevalence of left ventricular ( LV ) thrombosis and incidence of arterial embolism  after acute anterior myocardial infa rct ion ( AAMI ) treated with streptokinase 1.5 
    Output:
    
Surprisingly , TOTAL showed no difference in the primary efficacy outcome between the two approaches , but a significant increase in stroke .
Thus thrombectomy is associated with an increase in stroke , but , based on a meta- analysis of all trials , possibly with a trend towards reduced mortality .
Endovascular therapy significantly improved the rate of functional independence compared with fibrinolysis alone