Perioperative Heparin Bridging Research Articles

Perioperative bridging anticoagulation in patients with oral cancer surgery: a multicenter retrospective study

The number of patients administered oral antithrombotic drugs who require elective surgery has increased. Perioperative heparin bridging needs to be considered for patients at a high risk of thromboembolism. The present study investigated the effects of perioperative heparin bridging therapy on perioperative complications (postoperative bleeding and thrombotic events) in oral cancer surgery. The medical records of 98 patients who underwent oral cancer surgery with perioperative bridging therapy were retrospectively analyzed. Postoperative hemorrhage occurred in 16 patients (16.3%) and thrombotic events (deep venous thrombosis) in 5 (5.1%), which were higher than in other surgeries. A multivariate analysis identified the administration of prostaglandins as the only significant independent risk factor for postoperative hemorrhage, and a longer duration of postoperative heparin bridging therapy was associated with the incidence of deep venous thrombosis. The present results suggest a higher incidence of thrombotic and bleeding events in patients who underwent oral cancer surgery with heparin bridging, and the nature of surgery (such as revascularization and prolonged bed rest) may be a contributing factor. Future studies are needed to establish whether heparin bridging is effective in oral cancer surgery.

Safety of Hepatobiliary and Pancreatic Surgery in Patients Receiving Direct Oral Anticoaulants (DOACs)

Introduction: The safety and optimal perioperative management of patients receiving direct oral anticoagulants (DOACs) during hepatobiliary and pancreatic (HBP) surgery is still controversial. Methods: Between 2012 and 2018, 115 anticoagulant-prescribed patients who underwent elective HBP surgery (65 benign and 50 malignant diseases, 69 laparoscopic and 46 open-fashioned operations) in our department were enrolled in this study. Patients undergoing emergency operations were excluded from the study. The patients were divided into two groups; patients receiving DOACs (DOAC group, n = 35) and patients undergoing warfarin therapy (WF group, n = 80). Background characteristics, surgical blood loss, and postoperative complications, including bleeding and thrombotic complications, were compared between the groups. Results: In the DOAC group, dabigatran, apixaban, rivaroxaban, and edoxaban were used in 10, 8, 10, and 7 patients, respectively, and only 11 patients (31.4%) received perioperative heparin bridging. There were no differences in patients´ background characteristics and mode of surgery (open or laparoscopic). The duration of operation (p = 0.148), surgical blood loss (p = 0.782), and the rate of intraoperative red blood cell transfusion (p = 1.000) were similar between the groups. Overall, any thromboembolic complications were not observed in the current cohort, and only 1 patient (2.9%) suffered from postoperative bleeding complication in the DOAC group. The mortality was zero, and the length of postoperative stay was also identical between the groups (p = 0.998). Conclusion: HBP surgery is safely performed in patients receiving DOAC therapy, without increase in bleeding or thromboembolic complications compared with warfarin therapy.

Impact of antithrombotic therapy on the outcomes with focus on bleeding and thromboembolic events in patients undergoing pancreticoduodenectomy.

We investigated perioperative outcomes of pancreaticoduodenectomy (PD) in patients receiving antithrombotic therapy (ATT) with a focus on the incidence of perioperative bleeding and thromboembolic complications. A total of 77 patients who underwent PD at our institution between 2013 and 2019 were retrospectively reviewed. Clinical findings and surgical outcomes including bleeding and thromboembolic complications were compared in patients with or without ATT. Interruption of ATT and perioperative heparin bridging were based on our hospital protocol. Among ATT (30) and non-ATT (47) groups, ATT group had a significantly higher age and history of cardiocerebrovascular diseases. No significant difference was observed in intraoperative and post-pancreatectomy haemorrhage (PPH) between the groups. ATT group was associated with a significantly higher rate of post-operative complications, Clavien-Dindo classification ≥II and thromboembolic events. Operative mortality in ATT and non-ATT groups was 2 (6.7%) and 1 (2.1%), respectively. There was no significant association between ATT and excessive intraoperative blood loss (≥1000 mL), PPH (≥grade B) and thromboembolic complications (Clavien-Dindo classification ≥II). In patients with ATT, PD is a feasible procedure with no major impact on intraoperative bleeding or PPH.

Perioperative antithrombotic management of patients who receive direct oral anticoagulants during gastroenterological surgery.

AimWe investigated the effect of perioperative management of direct oral anticoagulants (DOACs) on bleeding and thromboembolic complications during gastroenterological (GE) surgery.MethodsA total of 334 patients receiving anticoagulants and undergoing elective GE surgery between 2012 and 2018 were enrolled. The patients were divided into three groups: patients receiving warfarin (WF, n = 231), patients receiving DOACs with heparin bridging (DOAC‐HB, n = 34), and patients receiving DOAC without heparin bridging (DOAC‐NHB, n = 69). Outcome variables were compared between the groups and the risk factors of postoperative bleeding were assessed using logistic multivariate analysis.ResultsNo significant differences were observed in background characteristics between the groups. There were similarities between the groups in surgical blood loss (P = .772) and rate of intraoperative transfusion (P = .952). Thromboembolic complications only occurred in two patients in the WF group (0.9%), and no thromboembolism occurred in the DOAC groups. The incidence of major postoperative bleeding was significantly higher in DOAC‐HB group than in the other groups (14.7% vs 4.8% vs 1.4%, P = .011). Multivariate analysis showed DOAC with heparin bridging to be the most significant risk factor of major postoperative bleeding (odds ratio = 11.60, P = .028).ConclusionsElective GE surgery can be safely performed in patients receiving DOACs without heparin bridging. Perioperative heparin bridging during DOAC interruption is not recommended even for patients undergoing major GE surgery due to increased postoperative bleeding.

The impact of perioperative heparin bridging therapy in lung cancer surgery.

The impact of perioperative heparin bridging (HB) for lung surgery in patients on anti-clotting drugs remains unclear. We performed a retrospective study to assess its effect on surgical safety by comparing HB and non-HB groups. This study included 274 consecutive patients on anti-clotting drugs who underwent surgery for lung cancer. Of these, 77 received HB and 197 did not. Propensity score matching extracted 124 patients, consisting of 62 patients with HB and 62 patients without HB. Endpoints were surgical safety. There was no statistically significant difference in the outcomes of surgical safety outcomes between the HB and non-HB group after propensity-score matching, operative time (172 vs. 203min, p = 0.131), volume of blood loss (60 vs. 70ml, p = 0.335), need for intraoperative RBC transfusion (3.2 vs. 6.5%, p = 0.680), chest tube drainage volume on the 1st postoperative day (200 vs. 200ml, p = 0.796), and chest tube placement duration (3 vs. 3days, p = 0.606). The influence of perioperative HB on postoperative thromboembolic or bleeding events in lung cancer surgery is not obvious, but its surgical safety appears to be acceptable.

Perioperative Anticoagulant Use for Surgery Evaluation (PAUSE) Study: A Perioperative Management Plan for Patients with Atrial Fibrillation Who Are Receiving a Direct Oral Anticoagulant

Introduction: The perioperative management of patients who are taking a direct oral anticoagulant (DOAC) for atrial fibrillation (AF) and require an elective surgery/procedure is uncertain. No studies have addressed the timing of perioperative DOAC interruption and resumption, and if perioperative heparin bridging and coagulation function testing are needed. The Perioperative Anticoagulant Use for Surgery Evaluation (PAUSE) Study hypothesized that a simple, standardized perioperative management strategy, based on DOAC-specific interruption and resumption intervals, that foregoes perioperative heparin bridging and coagulation function testing, is safe for patient care, with associated low rates of major bleeding (1%) and arterial thromboembolism (0.5%). We postulated that this management yields a high proportion of patients (>90%) with a minimal to no DOAC level at surgery/procedure. Methods: PAUSE is a prospective study with 3 parallel DOAC cohorts of patients with AF taking apixaban, dabigatran or rivaroxaban and requiring anticoagulant interruption for an elective surgery/procedure. Patients were managed using a standardized protocol based on DOAC pharmacokinetic properties, procedure-associated bleeding risk (Appendix 1) and creatinine clearance (CrCl). DOACs were interrupted for 1 day before and after surgery for a low bleed risk surgery and 2 days before and after a high bleed surgery; longer interruption was done in patients on dabigatran with a CrCl Results: We enrolled 3007 patients from 23 sites in Canada, the U.S. and Europe (Appendix 4). The patient characteristics were (Figure 2): mean age 72.5 years; 66.1% male; 33.5% high bleeding risk surgery/procedure, with 1257 patients in the apixaban cohort, 668 in the dabigatran cohort and 1082 in the rivaroxaban cohort (Table 1). DOAC interruption and resumption intervals are shown in Table 2. The 30-day postoperative rate (95% CI) of major bleeding was 1.35% (0-2.00) in the apixaban cohort, 0.90% (0-1.73) in the dabigatran cohort and 1.85% (0-2.65) in the rivaroxaban cohort; the rate (95% CI) of arterial thromboembolism was 0.16% (0-0.48) in the apixaban cohort, 0.6% (0-1.33) in the dabigatran cohort and 0.37% (0-0.82) in the rivaroxaban cohort (Table 3). There were 2541 (84.5%) patients with preoperative DOAC levels measured: a level Conclusions: In patients with AF who were taking a DOAC (apixaban, dabigatran, rivaroxaban) and required anticoagulant interruption for an elective surgery/procedure, using a standardized DOAC-specific perioperative management strategy was safe for patient care, with associated low rates of perioperative MB ( 90% overall; 98.8% at high bleeding risk) had a minimal or no residual DOAC level at the time of the surgery/procedure. PAUSE is the largest study, to date, that addresses how to manage the common problem of perioperative DOAC management. It is likely to have a practice-changing impact and will inform future practice guidelines in perioperative care. Study Funding: CIHR (313156) and the H&S Foundation of Canada (G-14-0006136). Aniara-Hyphen Biomed (assays). Acknowledgements: We thank Drs. Walter Ageno, David Garcia, Lehana Thabane, Wendt Lim, Lori Linkins, William Ristevski, and Demetrios J. Sahlas. Also, Kayla Lucier, Grace Wang, Tara McDougall, and HRLMP and CRLB. Supported by CanVector and REDCap. Disclosures Douketis:Bayer: Other: Advisory Board; Janssen: Consultancy; BMS: Other: Advisory Board; Biotie: Other: Advisory Board; Daiichi-Sankyo: Other: Advisory Board; Boehringer-Ingelheim: Consultancy, Other: Advisory Board, Research Funding; The Medicines Company: Other: Advisory Board; Sanofi: Consultancy, Other: Advisory Board; Astra-Zeneca: Other: Advisory Board; Portola: Other: Advisory Board; Pfizer: Other: Advisory Board. Spyropoulos:Janssen Scientific Affairs, LLC: Consultancy. Carrier:Bayer: Honoraria; Leo Pharma: Research Funding; Pfizer: Honoraria; BMS: Honoraria, Research Funding. Vanassche:Bayer: Consultancy; Boehringer Ingelheim: Consultancy; BMS/Pfizer: Consultancy. Verhamme:Bayer: Honoraria, Research Funding; Medtronic: Honoraria; Portola: Honoraria; Boehringer Ingelheim: Honoraria; Leo Pharma: Honoraria, Research Funding; BMS: Honoraria, Research Funding; Daiichi-Sankyo: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding. Shivakumar:Pfizer: Honoraria; Servier: Honoraria; Bayer: Honoraria; LEO Pharma: Honoraria. Gross:Pfizer: Honoraria; Bayer: Honoraria; LEO Pharma: Honoraria; Servier: Honoraria. Lee:Pfizer: Consultancy, Research Funding; BMS: Research Funding; Servier: Honoraria; LEO Pharma: Consultancy, Research Funding; Bayer: Consultancy, Honoraria. Le Templier:BMS-pfizer: Honoraria. Wu:Leo Pharma: Honoraria; Pfizer: Honoraria; BMS-Pfizer: Honoraria. Coppens:Bayer: Honoraria, Other: Non-financial support, Research Funding; CSL Behring: Honoraria, Other: non-financial support, Research Funding; Uniqure BV: Research Funding. Arnold:Bristol Myers Squibb: Research Funding; UCB: Consultancy; Amgen: Consultancy, Research Funding; UCB: Consultancy; Amgen: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Bristol Myers Squibb: Research Funding; Novartis: Consultancy, Research Funding. Caprini:Alexion Pharmaceuticals: Membership on an entity9s Board of Directors or advisory committees; Recovery Force: Consultancy; BMS: Membership on an entity9s Board of Directors or advisory committees; Pfizor: Membership on an entity9s Board of Directors or advisory committees; Janssen RD Bayer: Honoraria; Sanofi: Honoraria; Boehringer-Ingelheim: Honoraria, Research Funding.

Safety of laparoscopic surgery in digestive diseases with special reference to antithrombotic therapy: A systematic review of the literature.

AIMTo elucidate the effect of antithrombotic therapy (ATT) on bleeding and thromboembolic complications during or after laparoscopic digestive surgery.METHODSPublished articles or internationally accepted abstracts between 2000 and 2017 were searched from PubMed, Cochrane Database, and Google Scholar, and studies involving laparoscopic digestive surgery and antiplatelet therapy (APT) and/or anticoagulation therapy (ACT) were included after careful review of each study. Data such as study design, type of surgical procedures, antithrombotic drugs used, and surgical outcome (both bleeding and thromboembolic complications) were extracted from each study.RESULTSThirteen published articles and two internationally accepted abstracts were eligible for inclusion in the systematic review. Only one study concerning elective laparoscopic cholecystectomy in patients with perioperative heparin bridging for ACT showed that the risk of postoperative bleeding was higher compared with those without ACT. The remaining 14 studies reported no significant differences in the incidence of bleeding complications between the ATT group and the group without ATT. The risk of thromboembolic events (TE) associated with laparoscopic digestive surgery in patients receiving ATT was not significantly higher than those with no ATT or interrupted APT.CONCLUSIONLaparoscopic digestive surgery in ATT-burdened patients for prevention of bleeding and TE showed satisfactory results. The risk of hemorrhagic complication during or after these procedures in patients with continued APT or heparin bridging was not significantly higher than in patients with no ATT or interrupted APT.

Short-Term Risk of Bleeding During Heparin Bridging at Initiation of Vitamin K Antagonist Therapy in More Than 90000 Patients WithNonvalvular Atrial Fibrillation Managed in Outpatient Care.

BackgroundSeveral studies have recently examined the risks of bleeding and of ischemic stroke and systemic embolism associated with perioperative heparin bridging anticoagulation in patients with nonvalvular atrial fibrillation. However, few studies have investigated bridging risks during vitamin K antagonist initiation in outpatient settings.Methods and ResultsA retrospective cohort study was conducted on individuals starting oral anticoagulation between January 2010 and November 2014 for nonvalvular atrial fibrillation managed in outpatient care and identified from French healthcare insurance. Bleeding and ischemic stroke and systemic embolism events were identified from the hospitalization database. Adjusted hazard ratios with 95% CI were estimated using Cox models during the first and 2 following months of anticoagulation. Of 90 826 individuals, 30% had bridging therapy. A total of 318 (0.35%) cases of bleeding and 151 (0.17%) ischemic stroke and systemic embolism cases were identified during the first month of follow‐up and 231 (0.31%) and 122 (0.16%) during the 2 following months, respectively. At 1 month of follow‐up, the incidence of bleeding was higher in the bridged group compared with the nonbridged group (0.47% versus 0.30%; P<0.001), and this increased risk persisted after adjustment for covariates (hazard ratio=1.60; 95% CI, 1.28–2.01). This difference disappeared after the first month of treatment (0.93; 0.70–1.23). No significant difference in the occurrence of ischemic stroke and systemic embolism was observed either at 1 month of follow‐up or later.ConclusionsAt vitamin K antagonist initiation for nonvalvular atrial fibrillation managed in ambulatory settings, bridging therapy is associated with a higher risk of bleeding and a similar risk of arterial thromboembolism compared with no bridging therapy.

Perioperative Heparin Bridging in Atrial Fibrillation Patients Requiring Temporary Interruption of Anticoagulation: Evidence from Meta-analysis

Patients with atrial fibrillation (AF) often require temporary interruption of warfarin for an elective operation or invasive procedure. However, the safety and efficacy of periprocedural bridging anticoagulation with unfractionated heparin (UH) or low-molecular-weight heparin (LMWH) are still unclear. We evaluated the safety of periprocedural heparin bridging in AF patients requiring temporary interruption of oral anticoagulation. We searched the literature for trials that compared heparin bridging with no bridging in AF patients for whom warfarin was temporarily interrupted. The incidence of all-cause mortality, thromboembolism, and major and all bleeding was included, and meta-analysis was performed. A total of 13,808 patients with AF were included in 4 observational studies, 1 randomized trial, and 1 subgroup analysis of a randomized trial. The mean CHADS2 score for the no heparin bridging group was 2.49 and that for the heparin bridging group was 2.34. At 30 days and up to 3 months, when compared to the heparin bridging group, the no bridging group did not have any significant difference in mortality (odds ratio [OR], 1.29; 95% confidence interval [CI], .15-11.52; P = .82) or cerebrovascular accidents (OR, .93; 95% CI, .34-2.51; P = .88), but the no bridging group had significantly less major bleeding (OR, .41; 95% CI, .24-.68; P = .0006). Among AF patients with intermediate CHADS2 scores who are anticoagulated with warfarin and who required temporary interruption of warfarin for an elective surgery or procedure, periprocedural bridging with UH or LMWH was associated with a higher rate of major bleeding with no significant difference in mortality or CVA.

Postoperative Strokes and Intracranial Bleeds in Patients With Atrial Fibrillation: The FibStroke Study.

Patients with atrial fibrillation (AF) frequently undergo invasive procedures. Optimal perioperative use of oral anticoagulation (OAC) and heparin bridging is not well defined. Discontinuation of OAC for minor procedures/operations places AF patients at risk for thromboembolism. In this study, we assessed perioperative antithrombotic treatment in patients with AF who suffered a postoperative stroke or intracranial bleeding. The FibStroke Study includes AF patients with an ischemic stroke or intracranial bleed identified from the discharge registries of 4 Finnish hospitals. In total, 3632 consecutive patients developed 3252 ischemic strokes and 794 intracranial bleeds. All invasive procedures during the 30 days preceding the stroke or intracranial bleed were identified. A total of 194/3252 (6.0%) ischemic strokes and 23/794 (2.9%) intracranial bleeds were preceded by a procedure. Altogether, 69% of the patients were on OAC prior to index procedure, OAC was interrupted in 81.2% of the procedures preceding a stroke, and heparin bridging was used in 27.8% of interruptions. Of the procedures leading to stroke, 42.3% were low-bleeding-risk procedures, and OAC was interrupted in 84.7% of these procedures. The median time from procedure to stroke was 4 days. Heparin bridging was used in 54.5% of OAC interruptions preceding intracranial bleeding and combination of anticoagulation with antiplatelet therapy by 43.5% of patients with postoperative intracranial bleeding. Perioperative interruption of OAC is common in patients who suffer a postoperative stroke, even in patients with low-bleeding-risk procedures. Postoperative intracranial bleeding is frequently preceded by perioperative heparin bridging.

Effects of heparin bridging anticoagulation on perioperative bleeding and thromboembolic risks in patients undergoing abdominal malignancy surgery.

Recent publications provided controversial results indicating that perioperative heparin bridging anticoagulation (HBA) increased the bleeding risk without decreasing the thromboembolic risk in patients undergoing minor surgery. To investigate if this is also the case in high-risk patients undergoing major abdominal malignancy surgery, we retrospectively collected data of 3268 patients over a 10-year period. After the interruption of preoperative antithrombotic agents, HBA was initiated with a prophylactic-dose of unfractionated heparin in 133 patients (HBA group), and 62 patients did not receive HBA (non-HBA group). The incidence of exogenous blood transfusion (EBT) and thromboembolic events (TEEs) within 30days after surgery were compared between the HBA and non-HBA groups. The results showed that the incidence of EBT and TEEs was similar between the two groups (23.3 vs 19.4%; P=0.535) and (4.1 vs 3.2%; P=0.821), respectively. The amount of intraoperative bleeding and the length of postoperative hospital stay were also similar [median (quantile 1-3); 192 (71-498) vs 228 ml (100-685); P=0.422] and [12 (9-19) vs 14.5days (10-21); P=0.052], respectively. These findings may suggest it is unlikely that prophylactic-dose HBA affects bleeding and thromboembolic risks in patients undergoing major abdominal malignancy surgery.

Effect of antiplatelet therapy on patients undergoing gastroenterological surgery: thromboembolic risks versus bleeding risks during its perioperative withdrawal.

Antiplatelet agents given to prevent thromboembolic disease are frequently withdrawn prior to surgical procedures to reduce bleeding complications. This action may expose patients to increased thromboembolic morbidity and mortality. A series of 2012 patients who had undergone gastroenterologic surgery between January 2005 and June 2010 at our institution were reviewed. Among this cohort, antiplatelet therapy (APT) was used in 519 patients (25.8 %). The perioperative management included interruption of APT 1 week before surgery and early postoperative reinstitution in patients at low thromboembolic risk, although APT was maintained until surgery in those at high thromboembolic risk. Bleeding and thromboembolic complications, as well as other outcome variables, were assessed in patients with and without APT. Among 519 patients with APT, 99 (19.1 %) underwent multidrug APT. Among them, 124 (23.9 %) required preoperative continuation of APT. None suffered from excessive bleeding intraoperatively. There were 19 thromboembolic events (0.9 %) in the whole cohort. Postoperative bleeding complications occurred in 37 patients (1.8 %). Multivariate analysis showed that increased postoperative bleeding complications were independently associated with multidrug APT [hazard ratio (HR) 4.3, p = 0.014], high-risk surgical procedures (HR 3.5, p = 0.003), and perioperative heparin bridging (HR 2.8, p = 0.029). High-risk surgery (HR 8.3, p < 0.001) and poor performance status (HR 4.9, p = 0.005)--but neither APT nor anticoagulation use--were significant prognostic factors for thromboembolic complications. Satisfactory outcomes were obtained during gastroenterologic surgery under rigorous perioperative management, including single-agent APT continuation in patients at high thromboembolic risk. Patients treated with multidrug APT still represent a challenging group, however, and need to be carefully managed to prevent perioperative complications.

Perioperative Heparin Bridging in Patients Receiving Oral Anticoagulation: Meta-Analysis of Bleeding and Thromboembolic Rates

Abstract 545 Background:Periprocedural bridging using unfractionated heparin (UFH) or low molecular weight heparin (LMWH) in patients receiving chronic oral anticoagulation (OAC) is often utilized with the view to reduce the risk of thromboembolic (TE) events. Optimal perioperative anticoagulant methods have not been established. Methods: Systematic review and meta-analysis of published English-language studies from 2001 to 2010 examining bleeding and TE events in patients receiving bridging therapy during temporary OAC interruption for elective procedures. Results: A search of MEDLINE, EMBASE and Cochrane Collaboration databases yielded 32 studies on 6760 bridged patients. Studies were reviewed by 2 independent data collectors (k=0.869). Study quality was generally poor with risk of bias. Thirty-one studies were observational with 1 randomized controlled trial. Low TE risk and/or non-OAC patient groups were used for comparison in 12 observational studies. Major (22/32, 68.8%) and non-major (27/32, 84.4%) procedures were represented. TE events occurred in 67 of 6760 bridged (0.87%; 95% CI 0.40%–1.35%) and 29 of 4897 non-bridged (0.77%; 95% CI 0.24%–1.30%) patients. Using a random effects model, there was no difference in the risk of TE events in bridged versus non-bridged patients (OR 1.02, 95% CI 0.53–1.95). Bridged patients had a significantly increased risk of overall bleeding (OR 5.47, 95% CI 3.89–7.70) and major bleeding (OR 3.43, 95% CI 1.13–10.4) compared to non-bridged patients. There was no difference in TE events (OR 2.44, 95% CI 0.34–17.4) or overall bleeding (OR 2.40 95% CI 0.72–8.05) in patients receiving full versus intermediate/low dose LMWH. Summary: Patients receiving heparin bridging during OAC interruption appear to be at increased risk of bleeding and similar risk of TE events compared to non-bridged patients. Studies of high methodologic quality are needed to develop an optimal anticoagulation strategy and inform clinical decision-making. Disclosures:Lim:Leo Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bayer: Consultancy; Pfizer: Honoraria. Kaatz:Boehringer-Ingelheim: Consultancy, Research Funding, Speakers Bureau; Bristol Myer Squibb: Consultancy, Research Funding; Bayer: Research Funding; National Institute of Health: Research Funding; Canadian Institute of Health Research: Research Funding; Pfizer: Consultancy; Johnson and Johnson: Consultancy; Ortho-McNeil: Consultancy; GlaxoSmithKline: Speakers Bureau; AC Forum: Membership on an entity's Board of Directors or advisory committees; National Certification Board of Anticoagulation Providers: Membership on an entity's Board of Directors or advisory committees; National Blood Clot Alliance: Membership on an entity's Board of Directors or advisory committees.