Case fatality of bleeding and recurrent venous thromboembolism during, initial therapy with direct oral anticoagulants: a systematic review.

The frequency and case fatality of venous thromboembolism (VTE) and major bleeding during the initial 3 months of therapy in those treated for symptomatic VTE with either direct oral anticoagulants (DOACs) or vitamin K antagonists (VKA) are important clinically relevant outcomes. We sought to measure it during the initial months of anticoagulation for symptomatic VTE. We searched MEDLINE, EMBASE, and CENTRAL to identify studies that enrolled patients with acute symptomatic VTE treated with DOACs or VKA and reported data on bleeding, VTE recurrence and death. Studies were evaluated according to a priori inclusion criteria and critically appraised using established internal validity criteria. Single-proportion random-effects models were used to pool estimates. Of the 2453 citations retrieved, 5 RCTs that enrolled 24,507 patients were included. The rate of major bleeding was 1.8 (95% CI: 1.3-2.5) and 3.1 (95% CI: 2.4-3.9) per 100 patient-years in DOAC and VKA arms, respectively. The rate of VTE recurrence was 3.7 (95% CI: 2.7-4.7) and 4.1 (95% CI: 3.0-5.4) per 100 patient-years of DOAC and VKA, respectively. The case fatality rate of bleeding was significantly higher in the VKA arms 10.4% (95% CI: 6.6-15.4) compared to DOACs 6.1% (95% CI: 2.7-11.7; p value for difference=0.029) with no statistical difference between the case fatalities for recurrent VTE. The rate of death from either definite major bleeding or definite recurrent VTE was 0.27 (95% CI: 0.16-0.40) and 0.46 (95% CI: 0.32-0.63) per 100 patient-years for DOACs and VKAs respectively, resulting in a number needed to treat of 875 for DOACs to prevent one death. DOACs are attractive alternatives to VKAs for initial treatment of symptomatic VTE, with lower frequency and case fatality for major bleeding. However, the incremental safety benefit of DOACs over VKAs is small, with large numbers needed to treat.

Wu C ，Alotaibi GS ，Alsaleh K ，Sean McMurtry M ... -  《-》

Case-fatality of recurrent venous thromboembolism and major bleeding associated with aspirin, warfarin, and direct oral anticoagulants for secondary prevention.

The duration of anticoagulation after venous thromboembolic events (VTE) is based on the balance between the risk of recurrent VTE and bleeding. The purpose of this study was to estimate the frequency and case-fatality rate of major bleeding and recurrent VTE during secondary prevention of VTE. MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials databases were searched through September 2014. Two reviewers independently screened citations to identify trials that enrolled patients for secondary prevention of VTE with direct oral anticoagulants (DOACs), vitamin K antagonists (VKAs), aspirin or placebo. Two reviewers independently extracted data onto standardized forms. Twelve RCTs that enrolled 10,542 patients were included. The rate of major bleeding was 1.6 per 100 patient-years (95% CI, 1.2-2.1), and 0.58 per 100 patient-years (95% CI, 0.24-1.1) on VKAs and DOACs, respectively, with an incidence rate ratio of 0.35 (95% CI, 0.17-0.68, p=0.0023). The case-fatality rates for DOACs and VKAs were not significantly different at 0% (95% CI, 0.0-15.4) and 6.8% (95% CI, 1.4-18.6), respectively. The rate of recurrent VTE was not different between DOACs and VKA, IRR 0.88 (95% CI, 0.15-4.8, p=0.88). Case-fatality rates for recurrent VTE for DOAC and VKAs were 10.8% (95% CI, 4.4-20.9) and 5.6% (95% CI, 1.2-15.4), respectively. Only DOACs showed a significant reduction in the composite outcome of fatal recurrent VTE and fatal bleeding when compared to placebo, IRR 0.40 (95% CI, 0.14-1.0, p=0.03). Case-fatality rates for major bleeding and recurrent VTE for DOACs appear to be similar to those for VKA and the composite of fatal events is lower for DOACs than placebo. Overall, given the favorable safety profile and comparable efficacy of DOAC therapy, the threshold to continue anticoagulation with DOACs after unprovoked VTE should be low if the baseline risk of anticoagulation-related bleeding is not high.

Wu C ，Alotaibi GS ，Alsaleh K ，Linkins LA ，McMurtry MS ... -  《-》

Anticoagulation for the long-term treatment of venous thromboembolism in people with cancer.

Kahale LA ，Hakoum MB ，Tsolakian IG ，Matar CF ，Terrenato I ，Sperati F ，Barba M ，Yosuico VE ，Schünemann H ，Akl EA ... -  《Cochrane Database of Systematic Reviews》

Case Fatality Rates of Recurrent Thromboembolism and Bleeding in Patients Receiving Direct Oral Anticoagulants for the Initial and Extended Treatment of Venous Thromboembolism: A Systematic Review.

In patients with venous thromboembolism (VTE), the study of the case fatality rate (CFR) of VTE recurrences and bleeding complications may be of help to balance the risks and benefits of anticoagulant therapy. To investigate the CFR with the direct oral anticoagulants (DOACs; dabigatran, rivaroxaban, apixaban, and edoxaban) in patients with VTE. We conducted a systematic review and meta-analysis of randomized clinical trials testing the DOACs versus standard initial treatment of VTE (parenteral anticoagulant for ≥5 days plus vitamin K antagonists [VKAs] for ≥3 months) and DOACs versus placebo or VKA for extended treatment. Two investigators independently extracted the data. A random effects meta-analysis was conducted using StatsDirect software. Overall, 10 trials in 35 029 patients were included. During initial treatment, the rate of recurrent VTE per 100 patient-years (%/yr) and CFR (%) was similar in patients receiving DOACs or standard therapy (4.1%/yr vs 4.4%/yr; P = .21 and 16% vs 13%; P = .61, respectively). However, major bleeding (1.8%/yr vs 3.1%/yr; P = .003), fatal bleeding (0.1%/yr vs 0.3%/yr; P = .02), and CFR (6% vs 10%; P = .18) were lower with DOACs than with standard therapy. During extended treatment, both all-cause mortality and recurrent VTE per 100 patient-years were lower with DOACs than with placebo (0.6%/yr vs 1.1%/yr; P = .01 and 1.9%/yr vs 10.9%/yr; P < .0001, respectively), but there were no statistical differences between treatments on CFR of VTE recurrences (P = .17). No fatal bleeding events were reported during extended treatment. The use of DOACs was associated with fewer major and fatal bleedings and corresponding CFR than standard initial treatment of VTE, and fewer recurrent VTEs and mortality than placebo during extended therapy, although the CFR of recurrent VTE was not reduced.

Gómez-Outes A ，Lecumberri R ，Suárez-Gea ML ，Terleira-Fernández AI ，Monreal M ，Vargas-Castrillón E ... -  《-》

Using oral anticoagulants among chronic kidney disease patients to prevent recurrent venous thromboembolism: A systematic review and meta-analysis.

Chronic kidney disease (CKD) increases the risk of venous thromboembolism (VTE) among affected patients. Vitamin K antagonists (VKA) and warfarin remains the main stay of its treatment. Due to novelty and unclear risk-to-benefit ratio of direct oral anti-coagulants (DOAC), they remain underutilized in preventing VTE among CKD patients. We aim to assess the efficacy and safety of DOACs and other oral anticoagulants in preventing recurrent VTE among high-risk population. We conducted a literature search using PubMed, Embase, Cochrane, Web of Science and Clinicaltrials.gov for randomized controlled trials (RCTs) comparing anti-coagulants like DOAC, LMWH or VKA or any oral anti-coagulant (OAC) (This includes VKAs and DOACs) with either placebo or another anti-coagulant. Two independent reviewers screened the retrieved articles and extracted data using a piloted data extraction sheet. The primary outcome of interest was number of recurrent VTE and other side effects among CKD patients receiving respective treatment. Secondary outcomes were risk of major, non-major and intra-cranial bleed. We retrieved 7244 titles on initial search, reviewed full text of 818 articles, and selected 10 phase III RCTS for quantitative meta-analysis. Out of 36,326 patients in these trials, only 10,840 (29.8%) were evaluable. We stratified patients into four categories based on severity of renal impairment using serum creatinine clearance (SCr) as the marker e.g. mild (>50 - <80) moderate (>30 - ≤50) severe (<30) and any level (from <30 to <80). There was no difference between DOACs vs VKA in decreasing the risk of recurrent VTE among patients with mild (RR:0.86, 95% CI:0.61-1.22, I2 = 25%) moderate/severe (RR:0.72, 95% CI:0.44-1.17, I2 = 0%) or any level of renal impairment (RR:0.83, 95% CI:0.60-1.14, I2 = 34%). No difference in efficacy between LMWH vs VKA among patients with moderate (RR:2.40, 95% CI:0.44-12.96, I2 = 76%) and any level (RR:2.59, 95% CI:0.66-10.16, I2 = 71%) of renal impairment respectively. Similarly, no difference in efficacy between LMWH vs any OAC (This includes VKAs and edoxaban) among patients with (RR:2.16, 95% CI:0.66-7.-06, I2 = 51%) and any level (RR:1.48, 95% CI:0.79-2.78, I2 = 78%) of renal impairment. DOACs compared to VKAs had significantly lower risk of combined major and non-major bleeding (RR: 0.74, 95% CI:0.65-0.84, I2 = 26%), major bleeding (RR: 0.51, 95% CI:0.38-0.69, I2 = 7%) and non-major clinically relevant bleeding (RR: 0.73, 95% CI:0.57-0.94, I2 = 45%) respectively. Risk of intracranial bleeding was comparable (RR: 0.68, 95% CI:0.19-2.44, I2 = 0%). There was no difference in the risk of major bleeding between LMWH vs any OAC (RR: 0.83, 95% CI:0.46-1.51, I2 = 0%). DOACS and other anticoagulants (VKA and LMWH) showed no statistical difference in preventing recurrent VTEs among CKD patients but DOACs had significantly lower risk of major and non-major clinically relevant bleeding irrespective of the level of renal impairment compared to VKAs. There was no difference in risk of intra-cranial bleeding between DOACs and VKAs.

Alhousani M ，Malik SU ，Abu-Hashyeh A ，Poznanski NJ ，Al-Hasan S ，Roth DF ，Alsharedi M ，Mustafa B ... -  《-》