***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 
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    Input: Background —When warfarin is interrupted for surgery , low-molecular-weight heparin is often used as bridging therapy . However , this practice has never been evaluated in a large prospect i ve study . This study was design ed to assess the efficacy and safety of bridging therapy with low-molecular-weight heparin initiated out of hospital . Methods and Results —This was a prospect i ve , multicenter , single-arm cohort study of patients at high risk of arterial embolism ( prosthetic valves and atrial fibrillation with a major risk factor ) .  Warfarin was held for 5 days preoperatively . Low-molecular-weight heparin was given 3 days preoperatively and at least 4 days postoperatively . Patients were followed up for 3 months for thromboembolism and bleeding .  Eleven Canadian tertiary care academic centers participated ; 224 patients were enrolled . Eight patients ( 3.6 % ; 95 % CI , 1.8 to 6.9 ) had an episode of thromboembolism , of which 2 ( 0.9 % ; 95 % CI , 0.2 to 3.2 ) were judged to be due to cardioembolism . Of these 8 episodes of thromboembolism , 6 occurred in patients who had warfarin deferred or withdrawn because of bleeding . There were 15 episodes of major bleeding ( 6.7 % ; 95 % CI , 4.1 to 10.8 ) : 8 occurred intraoperatively or early postoperatively before low-molecular-weight heparin was restarted , 5 occurred in the first postoperative week after low-molecular-weight heparin was restarted , and 2 occurred well after low-molecular-weight heparin was stopped . There were no deaths . Conclusions —Bridging therapy with subcutaneous low-molecular-weight heparin is feasible ; however , the optimal approach for the management of patients who require temporary interruption of warfarin to have invasive procedures is uncertain BACKGROUND Approximately 10 % of patients who undergo surgical procedures require chronic oral anticoagulation . Physicians must balance the thromboembolic and bleeding risks to make informed decisions on whether to continue anticoagulant medication . Evidence is lacking regarding the perioperative management of novel oral anticoagulant ( NOAC ) agents . This survey aims to describe the management of perioperative NOAC use during device implantation by Canadian centres . METHODS A Web-based tool was used to survey all Canadian adult pacemaker/defibrillator implant centres . The survey collected data regarding the perioperative management of NOACs  in atrial fibrillation patients at high risk for thromboembolism who undergo device implantation . RESULTS Twenty-two centres performed approximately 14,971 device implants ; 1150 ( 8 % ) of these implants were in patients who were prescribed a NOAC . In 82 % of centres , the NOAC is discontinued in anticipation of device implantation ; 73 % of these centres do not bridge with heparin . In patients with normal renal function at high risk of thromboembolic events ( Congestive Heart Failure , Hypertension , Age , Diabetes , Stroke/Transient Ischemic Attack ; CHADS2 ≥ 2 ) , 72 % of the centres restart the NOAC within 48 hours of the procedure . For patients with abnormal renal function ( glomerular filtration rate < 80 mL/min ) , the timing of NOAC discontinuation is variable . Hematoma rates vary from 0 to 30 % . CONCLUSIONS Most Canadian centres perform device implantation with NOAC interruption without the use of bridging . The timing of stopping and restarting anticoagulation and incidence of bleeding complications is variable . These findings emphasize the need for r and omized controlled studies to guide the optimal approach to management of NOACs during device implantation BACKGROUND Management of oral anticoagulation in patients undergoing pacemaker ( PPM ) or implantable cardioverter-defibrillator ( ICD ) implantation remains controversial . Prior studies demonstrate that continuation of warfarin may be safer when compared with strategies requiring interruption and /or heparin bridging . Limited data from r and omized trials exist . OBJECTIVE We conducted a r and omized trial to determine whether warfarin continuation is superior to warfarin interruption during PPM or ICD implantation . METHODS Patients on oral anticoagulation referred for PPM or ICD implantation were r and omized to warfarin continuation versus interruption . Patients r and omized to warfarin interruption were further stratified into two groups based on their risk for thromboembolic events in the absence of warfarin . Moderate-risk patients were r and omized to warfarin continuation versus warfarin interruption . High-risk patients were r and omized to warfarin continuation versus warfarin interruption with heparin bridging . The primary combined outcome included thromboembolic events , anticoagulant-related complications , or any significant bleeding necessitating additional intervention or discontinuation of anticoagulation . RESULTS We studied 100 patients ( average age 70.8 years , 21 % female , mean body mass index 28.4 ) who underwent 64 ICD and 36 PPM implantations . Fifty patients were assigned to continue warfarin . The r and omized groups were well matched . Among patients r and omized to warfarin interruption , there were two pocket hematomas , one pericardial effusion , one transient ischemic attack , and one patient who developed heparin-induced thrombocytopenia . No events were noted among patients continuing warfarin ( P = .056 ) . CONCLUSIONS While the results were not statistically significant , there was a trend toward reduced complications in patients r and omized to warfarin continuation . This strategy should be considered in patients undergoing PPM or ICD implantation OBJECTIVES The purpose of this r and omized study was to evaluate the prevalence of pocket hematomas in patients treated with heparin 6 h or 24 h after pacemaker or defibrillator implantation . BACKGROUND The risks of pocket hematoma and need for evacuation after device implantation have not been defined in patients who require anticoagulation . METHODS Forty-nine consecutive patients with an indication for anticoagulation with heparin after implantable defibrillator or pacemaker implantation were r and omized to receive intravenous heparin either 6 h ( n = 26 ) or 24 h ( n = 23 ) postoperatively . Both groups also received warfarin on a daily basis starting the evening of surgery . Twenty-eight patients who received postoperative warfarin alone and 115 patients who did not receive anticoagulation were followed up in a study registry . RESULTS A pocket hematoma developed in 6 of 26 patients ( 22 % ) who were treated with intravenous heparin 6 h postoperatively , as compared with 4 of 23 patients ( 17 % ) who were treated with intravenous heparin 24 h postoperatively ( p = 0.7 ) . In total , a pocket hematoma developed in 10 of 49 patients ( 20 % ) treated with heparin , 1 of 28 patients ( 4 % ) treated with warfarin alone and 2 of 115 ( 2 % ) patients who received no anticoagulation ( p < 0.001 ) . CONCLUSIONS Intravenous heparin initiation 6 h or 24 h after pacemaker or defibrillator implantation is associated with a 20 % prevalence of pocket hematoma formation . Warfarin therapy or no anticoagulation is associated with only a 2 % to 4 % risk of pocket hematoma formation BACKGROUND Periprocedural management of oral anticoagulation ( OAC ) in patients undergoing cardiac rhythm management ( CRM ) device implantation is controversial . Prior studies demonstrate that uninterrupted OAC may be safe , but limited data from r and omized trials exist . METHODS We conducted a multicenter , r and omized trial to evaluate the safety of uninterrupted OAC  during CRM device implantation . Patients on long-term warfarin ( N=213 ) treatment with contemporary indication for CRM device implantation were r and omized to uninterrupted versus interrupted ( 2 days ) OAC therapy . The primary outcome included major bleeding events necessitating additional intervention and thromboembolic events during 4 weeks follow-up . RESULTS The r and omized groups were well matched in terms of bleeding and thromboembolic risk . Only one ( 1 % ) patient in the uninterrupted OAC group ( N=106 ) needed blood transfusion due to rupture of proximal cephalic vein . Large hematomas were detected in 6 % of patients in both groups , but there was no need for pocket revision in either group . Any pocket hematoma was observed in 35 patients ( 33 % ) in the uninterrupted OAC group and in 43 patients ( 40 % ) with interrupted OAC and uninterrupted OAC strategy was non-inferior to interrupted OAC ( HR 0.86 , 95 % , p=0.001 for non-inferiority ) . One patient with interrupted OAC had stroke 3 days after the procedure . Hospital stay was comparable in all patient groups . CONCLUSION Our r and omized study demonstrates that CRM devices can be safely implanted without discontinuation of warfarin treatment AIM The aim of our study was to establish the efficiency of fibrin sealant in the prevention of pocket related complications in patients undergoing pacemaker implantation who are receiving anticoagulant treatment . METHODS The study was performed on 40 and 41 patients prospect ively r and omized into treatment and control groups who underwent pacemaker implantation procedure between January 2002 and July 2004 at the Pacemaker Center - Clinical Centre Nis , Serbia . Both groups of patients were receiving anticoagulant treatment with either heparin or warfarin .  Surgical procedures between the groups differed only in the application of fibrin sealant prior to wound closure in the treatment group . RESULTS In the treatment group , there were no pocket related complications while in the control group six patients ( 14.63 % ) had minor haematomas that required no treatment . Four patients ( 9.76 % ) had significant haematomas ( two patients were treated conservatively while the other two needed reintervention ) . The INR in the treatment group was 2.76+/-0.85 and in the control group 2.65+/-0.79 ( P = ns ) . In the follow-up period ( 2 - 27 months ) no late complications were registered in either group . CONCLUSION Fibrin sealant is an effective haemostatic agent . The results obtained in our study show that the administration of fibrin sealant in patients receiving anticoagulant treatment eliminates postoperative haematomas after pacemaker implantation Abstract Two hundred and thirty-four patients treated with continuous intravenous infusions of heparin were studied prospect ively to seek a relation between the activated partial thromboplastin tim BACKGROUND Many patients requiring pacemaker or implantable cardioverter-defibrillator ( ICD ) surgery are taking warfarin . For patients at high risk for thromboembolic events , guidelines recommend bridging therapy with heparin ; however , case series suggest that it may be safe to perform surgery without interrupting warfarin treatment . There have been few results from clinical trials to support the safety and efficacy of this approach . METHODS We r and omly assigned patients with an annual risk of thromboembolic events of 5 % or more to continued warfarin treatment or to bridging therapy with heparin .  The primary outcome was clinical ly significant device-pocket hematoma , which was defined as device-pocket hematoma that necessitated prolonged hospitalization , interruption of anticoagulation therapy , or further surgery ( e.g. , hematoma evacuation ) . RESULTS The data and safety monitoring board recommended termination of the trial after the second prespecified interim analysis . Clinical ly significant device-pocket hematoma occurred in 12 of 343 patients ( 3.5 % ) in the continued-warfarin group , as compared with 54 of 338 ( 16.0 % ) in the heparin-bridging group ( relative risk , 0.19 ; 95 % confidence interval , 0.10 to 0.36 ; P<0.001 ) . Major surgical and thromboembolic complications were rare and did not differ significantly between the study groups . They included one episode of cardiac tamponade and one myocardial infa rct ion in the heparin-bridging group and one stroke and one transient ischemic attack in the continued-warfarin group . CONCLUSIONS As compared with bridging therapy with heparin , a strategy of continued warfarin treatment at the time of pacemaker or ICD surgery markedly reduced the incidence of clinical ly significant device-pocket hematoma . ( Funded by the Canadian Institutes of Health Research and the Ministry of Health and Long-Term Care of Ontario ; BRUISE CONTROL Clinical Trials.gov number , NCT00800137 . ) The safety of pacemaker and defibrillator implantations in orally anticoagulated patients using st and ard techniques has not been thoroughly evaluated . This article describes a prospect ively collected experience in such patients . Patients presenting for device implantation who were treated with warfarin were allowed to continue therapy provided that the INR was < 3.5 . Implantations involved cannulation of the left axillary vein . Except for defibrillator leads , 7 Fr introducers were used , and all were leads actively fixated . The study included 47 patients who underwent implantation of permanent pacemakers ( n = 39 ) , defibrillators ( n = 5 ) , or biventricular pacemakers ( n = 3 ) . The 
    Output:
    
Uninterrupted use of OAC in the perioperative of CIED surgery was associated with a reduced risk of bleeding .