Patterns and Predictors of Use of Anticoagulants for the Treatment of Venous Thromboembolism Following Approval of Rivaroxaban

Oral Anticoagulation Therapy for Venous Thromboembolism in Norway: Time Trends and Treatment Patterns

PURPOSE

Data describing treatment patterns of patients with venous thromboembolism (VTE) patients in Scandinavia are scarce. This study sought to address this scarcity by describing demographic and clinical characteristics, trends in the use of oral anticoagulants (OACs), and treatment patterns in patients treated for VTE in Norway between 2013 and 2017.

METHODS

Using data from Norway's nationwide registries, a cohort study included patients newly (after 2008) treated OACs who were diagnosed with VTE between January 2013 and December 2017 and were dispensed an OAC (warfarin, apixaban, rivaroxaban, dabigatran, or edoxaban) within 30 days. Patient characteristics and the percentage of patients with VTE who initiated treatment with each OAC for each calendar year were reported. Initial therapy persistence was assessed using Kaplan-Meier curves and compared between the OAC groups using the log-rank test.

FINDINGS

The comorbidity burden was similar between patients taking warfarin and those taking apixaban but lower among patients taking rivaroxaban. Direct oral anticoagulant (DOAC) use increased from 33.2% to 93.6% during the study period, whereas warfarin use decreased. Persistence was higher in the apixaban cohort compared with the warfarin cohort, with the difference mostly apparent after 6 months, whereas persistence was similar between the patients taking rivaroxaban and those taking warfarin.

IMPLICATIONS

Between 2013 and 2017, DOAC use among patients with VTEs increased markedly in Norway, whereas the use of warfarin decreased. Patients taking apixaban had higher persistence compared with those taking warfarin, whereas patients taking warfarin and those taking rivaroxaban had similar persistence. Further studies with longer follow-up are required to examine the use of extended OAC treatment for VTE.

Anticoagulation Strategies in the Management of Lemierre Syndrome: A Systematic Review of the Literature

OBJECTIVE

To determine the optimal anticoagulation strategy in patients diagnosed with Lemierre Syndrome (LS).

DATA SOURCES

A systematic review in accordance with PRISMA guidelines was conducted using PubMed, MEDLINE, Scopus, ProQuest, and CINAHL from January to April 2020. Search terms included "Lemierre Syndrome" AND "anticoagulation" NOT "prophylaxis" OR "atrial fibrillation," in addition to a list of parenteral and oral anticoagulants. Adult patients who developed a clot and required systemic anticoagulation as a result of LS were included in this review.

STUDY SELECTION AND DATA EXTRACTION

A total of 4180 records were initially identified, though following the removal of duplicates and nonrelevant entries, 216 full-text articles were reviewed for inclusion; 13 articles were ultimately included.

DATA SYNTHESIS

The majority (11/14) of patients developed thromboses of the internal jugular veins, which corresponds to the pathophysiology of LS. Anticoagulation strategies were varied in the included literature, though 12/14 patients initially received a parenteral product. Two patients received a direct-acting oral anticoagulant (DOAC) following either intravenous heparin or subcutaneous enoxaparin and had outcomes similar to patients transitioned to warfarin.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Anticoagulation in LS is a clinical controversy because the thromboembolic events have rarely led to significant complications; thrombi typically resolve independently, and concerns for bleeding risks are well founded; however, this review indicates both the efficacy and safety of anticoagulation.

CONCLUSIONS

Anticoagulation is both efficacious and safe in LS, including treatment using a DOAC. Although further studies are needed, clinicians should consider a duration of anticoagulation of 6 to 12 weeks.

Anticoagulant therapies for acute venous thromboembolism among a cohort of patients discharged from Canadian urban and rural hospitals

OBJECTIVE

To determine anticoagulant therapy at hospital discharge for patients with acute venous thromboembolism (VTE) and secondarily, to describe factors affecting choice of therapy.

DESIGN

A retrospective chart review.

SETTING

Canadian hospitals in Edmonton, Alberta (n=4), Regina, Saskatchewan (n=2) and rural Alberta (n=3) from April 2014 to March 2015.

PARTICIPANTS

All patients discharged with an acute VTE were screened. Those with atypical clots, another indication for anticoagulation, pregnancy/breast feeding or lifespan <3 months were excluded.

PRIMARY AND SECONDARY OUTCOMES

Primarily, we identified the proportion of patients discharged from hospital with acute VTE that were prescribed either traditional therapy (parenteral anticoagulant±warfarin) or a direct oral anticoagulant (DOAC). Secondarily, management based on setting, therapy choice based on deep vein thrombosis (DVT) versus pulmonary embolism (PE), clot burden and renal function was compared. DOAC dosing was assessed (when prescribed), length of hospital stay based on therapy was compared and planned follow-up in the community was described.

RESULTS

Among the 695 patients included, most were discharged following a diagnosis of PE (82.9%) on traditional therapy (parenteral anticoagulant±warfarin) (70.2%) with follow-up by either a family doctor (51.5%) or specialist/clinic (46.9%) postdischarge. Regional variation was most evident between urban and rural sites. Of those prescribed a DOAC (28.3%), the majority were dosed appropriately (85.8%). DOAC use did not differ between those with DVT and PE, was proportionately higher for less severe clots and declined with worsening renal function. Patients prescribed DOACs versus traditional therapy had a shorter length of stay (4 vs 7 days, respectively).

CONCLUSIONS

Uptake of DOAC therapy for acute VTE was modest and may have been influenced by the timing of the audit in relation to the approval of these agents for this indication. Future audits should occur to assess temporal changes and ongoing appropriateness of care delivery.

Anticoagulant therapies for acute venous thromboembolism: a comparison between those discharged directly from the emergency department versus hospital in two Canadian cities

OBJECTIVE

To compare the characteristics/management of acute venous thromboembolism (VTE) for patients either discharged directly from the emergency department (ED) or hospitalised throughout a year within two urban cities in Canada.

DESIGN

Retrospective medical record review.

SETTING

Hospitals in Edmonton, Alberta (n=4) and Regina, Saskatchewan (n=2) from April 2014 to March 2015.

PARTICIPANTS

All patients discharged from the ED or hospital with acute deep vein thrombosis or pulmonary embolism (PE). Those having another indication for anticoagulant therapy, pregnant/breast feeding or anticipated lifespan <3 months were excluded.

PRIMARY AND SECONDARY OUTCOMES

Primarily, to compare proportion of patients receiving traditional therapy (parenteral anticoagulant±warfarin) relative to a direct oral anticoagulant (DOAC) between the two cohorts. Secondarily, to assess differences with therapy selected based on clot burden and follow-up plans postdischarge.

RESULTS

387 (25.2%) and 665 (72.5%) patients from the ED and hospital cohorts, respectively, were included. Compared with the ED cohort, those hospitalised were older (57.3 and 64.5 years; p<0.0001), more likely to have PE (35.7% vs 83.8%) with a simplified Pulmonary Embolism Severity Index (sPESI) ≥1 (31.2% vs 65.2%), cancer (14.7% and 22.3%; p=0.003) and pulmonary disease (10.1% and 20.6%; p<0.0001). For the ED and hospital cohorts, similar proportions of patients were prescribed traditional therapies (72.6% and 71.1%) and a DOAC (25.8% and 27.4%, respectively). For the ED cohort, DOAC use was similar between those with a sPESI score of 0 and ≥1 (35.1% and 34.9%, p=0.98) whereas for those hospitalised lower risk patients were more likely to receive a DOAC (31.4% and 23.8%, p<0.055). Follow-up was most common with family physicians for those hospitalised (51.5%), while specialists/VTE clinic was most common for those directly discharged from the ED (50.6%).

CONCLUSIONS

Traditional and DOAC therapies were proportionately similar between the ED and hospitalised cohorts, despite clear differences in patient populations and follow-up patterns in the community.

Management of acute venous thromboembolism among a cohort of patients discharged directly from the emergency department

OBJECTIVE

To report the proportion of patients discharged directly from the emergency department (ED) on traditional therapy (parenteral anticoagulant±warfarin) or a direct oral anticoagulant (DOAC) for the management of acute venous thromboembolism (VTE).

DESIGN

Retrospective medical record review across four EDs in Edmonton, Alberta, two in Regina, Saskatchewan and three in rural Alberta.

SETTING

EDs from April 2014 through March 2015.

PARTICIPANTS

Discharged directly from the ED with acute VTE. Patients were excluded if they had another indication for anticoagulants, were pregnant/breastfeeding or anticipated lifespan <3 months.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primarily, the proportion of patients discharged directly from the ED that were prescribed traditional therapy or a DOAC, with comparisons between Edmonton, Regina and rural Alberta. Secondarily, therapy selection was compared based on deep vein thrombosis (DVT) versus pulmonary embolism (PE) and clot burden. Dosing of DOACs was assessed (when applicable) and follow-up in the community was compared.

RESULTS

After screening 1723 patients, 417 (24.2%) were included with DVT and PE occurring in 65.5% and 34.5%, respectively. More patients with PE were discharged from EDs in Edmonton (43%) than Regina (7%). Overall, the majority of patients were discharged on traditional therapy (70.7%), with 27.8% receiving a DOAC. Uptake of DOAC use was highest in rural Alberta (53.3%) compared with Edmonton (29.6%) and Regina (12.1%). DOACs were more commonly prescribed for PE (34.0%) than DVT (24.5%) (p=0.04), proximal versus distal DVT (28.4% and 17.3%; p<0.001), and when prescribed were appropriately dosed in 79.3%. Follow-up most commonly occurred via a VTE clinic in Edmonton or family physician in Regina and rural Alberta.

CONCLUSIONS

Regional variation in discharging patients directly from the ED with PE is evident. While traditional therapy is most common, uptake of DOACs was modest given the timing of indication approval.

Rivaroxaban versus nadroparin for preventing deep venous thrombosis after total hip arthroplasty following femoral neck fractures: A retrospective comparative study

Objective This study was performed to evaluate the efficacy of rivaroxaban versus nadroparin for preventing deep venous thrombosis (DVT) in elderly patients with osteoporosis undergoing initial total hip arthroplasty (THA) for femoral neck fractures. Methods Prospectively maintained databases were reviewed to retrospectively compare elderly patients with osteoporosis who underwent initial THA for femoral neck fractures from 2007 to 2015. The patients received peroral rivaroxaban at 10 mg/day for 2 weeks or subcutaneous injections of nadroparin at 0.3 mL/day for 2 weeks until the primary analysis cut-off date. The time to first on-study DVT was the primary endpoint. Results In total, 399 patients were included (rivaroxaban group: n=200; mean age, 70.20 ± 9.16 years and nadroparin group: n = 199; mean age, 69.90 ± 8.87 years), with a mean 3-year follow-up. The time to first on-study DVT was significantly longer in the rivaroxaban than nadroparin group (12 and 5 days, respectively). The incidence of DVT within the 2-week follow-up was significantly higher in the nadroparin than rivaroxaban group (6.8% and 19.7%, respectively), but this difference was no longer present at the final follow-up. Conclusion Rivaroxaban was associated with a significant reduction in the occurrence of first on-study DVT compared with nadroparin.

Antithrombotic therapy for prophylaxis and treatment of venous thromboembolism in patients with cancer: review of the literature on current practice and emerging options

The treatment of cancer-associated venous thromboembolism (VTE) is difficult because cancer patients with VTE on anticoagulation are at an increased risk of bleeding compared with patients without VTE. This review summarises the evidence supporting the current standard of care and emerging treatment options. In difficult-to-treat subpopulations, where clinical data are often lacking, this review also provides the best clinical practice strategies based on the available data. The use of therapeutic doses of parenteral anticoagulants in patients with cancer-associated VTE for at least 3 to 6 months is supported by the current clinical data. After major cancer surgery, extended thromboprophylaxis for approximately 1 month following hospital discharge is also supported. In select populations of ambulatory cancer patients with solid tumours, or in patients with myeloma receiving immunomodulatory agents in combination with chemotherapy and/or corticosteroids, pharmacological prophylaxis could be considered. Although parenteral anticoagulants may not be tolerated by some patients, the data pertaining to the use of direct oral anticoagulants (DOACs) in cancer patients with VTE at this point can only be considered hypothesis generating. Clarity of the use of DOACs is awaiting the results of head-to-head trials between DOACs and parenteral anticoagulants. In addition, because of the lack of clinical trials, there are still unanswered questions on the optimal treatment regimens in subpopulations at increased risk of bleeding, including cancer patients with thrombocytopenia and those with brain metastases. For clinicians to balance the risk of recurrent thrombosis with the chance of bleeding, they need to assess the relevant clinical data. Current data support the use of parenteral anticoagulants in cancer patients with VTE, but many unanswered questions pertaining to the optimal regimens in special subpopulations and regarding the efficacy and safety of DOACs remain. To address this need, there are currently several clinical trials under way.

Rivaroxaban for the treatment of venous thromboembolism. The SWIss Venous ThromboEmbolism Registry (SWIVTER)

We investigated three-month clinical outcomes in patients with venous thromboembolism (VTE) treated with rivaroxaban or conventional anticoagulation in routine clinical practice. Between November 2012 and February 2015, 2,062 consecutive patients with VTE from 11 acute care hospitals in Switzerland were enrolled in the SWIss Venous ThromboEmbolism Registry (SWIVTER). Overall, 417 (20 %) patients were treated with rivaroxaban. In comparison to 1,645 patients on conventional anticoagulation, patients on rivaroxaban were younger (56 ± 18 vs. 65 ± 17 years; p<0.001), less often had pulmonary embolism (38 % vs 66 %; p<0.001), hypertension (26 % vs 41 %; p<0.001), cancer (10 % vs 28 %; p<0.001), congestive heart failure (10 % vs 17 %; p=0.001), diabetes (8 % vs 15 %; p<0.001), chronic lung disease (7 % vs 13 %; p=0.001), renal insufficiency (7 % vs 13 %; p=0.001), recent surgery (7 % vs 14 %; p<0.001), and acute coronary syndrome (1 % vs 4 %; p=0.009). VTE reperfusion therapy was more frequently used (28 % vs 9 %; p<0.001) and indefinite-duration anticoagulation treatment less often planned (26 % vs 39 %; p<0.001), respectively. In the propensity score-adjusted population, the risk of recurrent VTE was similar in patients on rivaroxaban vs conventional anticoagulation (1.2 % vs 2.1 %, hazard ratio [HR] 0.55, 95 % confidence interval [CI] 0.18-1.65; p=0.29); the risk of major bleeding was also similar, respectively (0.5 % vs 0.5 %, HR 1.00, 95 %CI 0.14-7.07; p=1.00). Conventional anticoagulation is still frequently used for the treatment of VTE, particularly in the elderly and those with comorbidities. Early clinical outcomes were comparable between propensity score-adjusted patient populations on rivaroxaban and conventional anticoagulation.