Alexei Plotnikov

Rivaroxaban in Patients with a Recent Acute Coronary Syndrome

BACKGROUND Acute coronary syndromes arise from coronary atherosclerosis with superimposed thrombosis. Since factor Xa plays a central role in thrombosis, the inhibition of factor Xa with low-dose rivaroxaban might improve cardiovascular outcomes in patients with a recent acute coronary syndrome. METHODS In this double-blind, placebo-controlled trial, we randomly assigned 15,526 patients with a recent acute coronary syndrome to receive twice-daily doses of either 2.5 mg or 5 mg of rivaroxaban or placebo for a mean of 13 months and up to 31 months. The primary efficacy end point was a composite of death from cardiovascular causes, myocardial infarction, or stroke. RESULTS Rivaroxaban significantly reduced the primary efficacy end point, as compared with placebo, with respective rates of 8.9% and 10.7% (hazard ratio in the rivaroxaban group, 0.84; 95% confidence interval [CI], 0.74 to 0.96; P=0.008), with significant improvement for both the twice-daily 2.5-mg dose (9.1% vs. 10.7%, P=0.02) and the twice-daily 5-mg dose (8.8% vs. 10.7%, P=0.03). The twice-daily 2.5-mg dose of rivaroxaban reduced the rates of death from cardiovascular causes (2.7% vs. 4.1%, P=0.002) and from any cause (2.9% vs. 4.5%, P=0.002), a survival benefit that was not seen with the twice-daily 5-mg dose. As compared with placebo, rivaroxaban increased the rates of major bleeding not related to coronary-artery bypass grafting (2.1% vs. 0.6%, P<0.001) and intracranial hemorrhage (0.6% vs. 0.2%, P=0.009), without a significant increase in fatal bleeding (0.3% vs. 0.2%, P=0.66) or other adverse events. The twice-daily 2.5-mg dose resulted in fewer fatal bleeding events than the twice-daily 5-mg dose (0.1% vs. 0.4%, P=0.04). CONCLUSIONS In patients with a recent acute coronary syndrome, rivaroxaban reduced the risk of the composite end point of death from cardiovascular causes, myocardial infarction, or stroke. Rivaroxaban increased the risk of major bleeding and intracranial hemorrhage but not the risk of fatal bleeding. (Funded by Johnson & Johnson and Bayer Healthcare; ATLAS ACS 2-TIMI 51 ClinicalTrials.gov number, NCT00809965.).

Rivaroxaban in Patients Stabilized After a ST-Segment Elevation Myocardial Infarction: Results From the ATLAS ACS-2–TIMI-51 Trial (Anti-Xa Therapy to Lower Cardiovascular Events in Addition to Standard Therapy in Subjects with Acute Coronary Syndrome–Thrombolysis In Myocardial Infarction-51)

OBJECTIVES The present analysis reports on the pre-specified subgroup of ST-elevation myocardial infarction (STEMI) patients, in whom anticoagulant therapy has been of particular interest. BACKGROUND In ATLAS ACS-2-TIMI-51 (Anti-Xa Therapy to Lower Cardiovascular Events in Addition to Standard Therapy in Subjects with Acute Coronary Syndrome-Thrombolysis In Myocardial Infarction-51), rivaroxaban reduced cardiovascular events across the spectrum of acute coronary syndrome (ACS). METHODS Seven thousand eight hundred seventeen patients in ATLAS ACS-2-TIMI 51 presented with a STEMI. After being stabilized (1 to 7 days), they underwent randomization to twice daily rivaroxaban 2.5 mg, rivaroxaban 5 mg, or placebo. Data are presented as 2-year Kaplan-Meier rates, and for intention-to-treat (ITT) and modified ITT (mITT) analyses. RESULTS Among STEMI patients, rivaroxaban reduced the primary efficacy endpoint of cardiovascular death, myocardial infarction, or stroke, compared with placebo (ITT: 8.4% vs. 10.6%, hazards ratio [HR]: 0.81, 95% confidence interval [CI]: 0.67 to 0.97, p = 0.019; mITT: 8.3% vs. 9.7%, HR: 0.85, 95% CI: 0.70 to 1.03, p = 0.09). This reduction emerged by 30 days (ITT and mITT: 1.7% vs. 2.3%, p = 0.042) and was evident in analyses that included events while patients received background dual antiplatelet therapies (ITT: 7.9% vs. 11.9%, p = 0.010; mITT: 7.7% vs. 10.1%, p = 0.061). In terms of the individual doses, rivaroxaban 2.5 mg reduced cardiovascular death (ITT: 2.5% vs. 4.2%, p = 0.006; mITT: 2.2% vs. 3.9%, p = 0.006), which was not seen with 5 mg of rivaroxaban. Rivaroxaban versus placebo increased non-coronary artery bypass grafting Thrombolysis In Myocardial Infarction major bleeding (2.2% vs. 0.6%, p < 0.001) and intracranial hemorrhage (0.6% vs. 0.1%, p = 0.015) without a significant increase in fatal bleeding (0.2% vs. 0.1%, p = 0.51). CONCLUSIONS In patients with a recent STEMI, rivaroxaban reduced cardiovascular events. This benefit emerged early and persisted during continued treatment with background antiplatelet therapies. Rivaroxaban compared with placebo increased the rate of major bleeding, but there was no significant increase in fatal bleeding. (An Efficacy and Safety Study for Rivaroxaban in Patients With Acute Coronary Syndrome; NCT00809965).

Clinically significant bleeding with low-dose rivaroxaban versus aspirin, in addition to P2Y12 inhibition, in acute coronary syndromes (GEMINI-ACS-1): a double-blind, multicentre, randomised trial

BACKGROUND Dual antiplatelet therapy (DAPT), aspirin plus a P2Y12 inhibitor, is the standard antithrombotic treatment following acute coronary syndromes. The factor Xa inhibitor rivaroxaban reduced mortality and ischaemic events when added to DAPT, but caused increased bleeding. The safety of a dual pathway antithrombotic therapy approach combining low-dose rivaroxaban (in place of aspirin) with a P2Y12 inhibitor has not been assesssed in acute coronary syndromes. We aimed to assess rivaroxaban 2·5 mg twice daily versus aspirin 100 mg daily, in addition to clopidogrel or ticagrelor (chosen at investigator discretion before randomisation), for patients with acute coronary syndromes started within 10 days after presentation and continued for 6-12 months. METHODS In this double-blind, multicentre, randomised trial (GEMINI-ACS-1) done at 371 clinical centres in 21 countries, eligible patients were older than 18 years with unstable angina, non-ST segment elevation myocardial infarction (NSTEMI) or ST segment elevation myocardial infarction (STEMI), with positive cardiac biomarkers and either ischaemic electrocardiographic changes or an atherosclerotic culprit lesion identified during angiography. Participants were randomly assigned (1:1) within 10 days after admission for the index acute coronary syndromes event to either aspirin or rivaroxaban based on a computer-generated randomisation schedule. Randomisation was balanced by using randomly permuted blocks with size of four and was stratified based on the background P2Y12 inhibitor (clopidogrel or ticagrelor) intended to be used at the time of randomisation. Investigators and patients were masked to treatment assignment. Patients received a minimum of 180 days of double-blind treatment with rivaroxaban 2·5 mg twice daily or aspirin 100 mg daily. The choice of clopidogrel or ticagrelor during trial conduct was not randomised and was based on investigator preference. The primary endpoint was thrombolysis in myocardial infarction (TIMI) clinically significant bleeding not related to coronary artery bypass grafting (CABG; major, minor, or requiring medical attention) up to day 390. Primary analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT02293395. FINDINGS Between April 22, 2015, and Oct 14, 2016, 3037 patients with acute coronary syndromes were randomly assigned; 1518 to receive aspirin and 1519 to receive rivaroxaban. 1704 patients (56%) were in the ticagrelor and 1333 (44%) in the clopidogrel strata. Median duration of treatment was 291 days (IQR 239-354). TIMI non-CABG clinically significant bleeding was similar with rivaroxaban versus aspirin therapy (total 154 patients [5%]; 80 participants [5%] of 1519 vs 74 participants [5%] of 1518; HR 1·09 [95% CI 0·80-1·50]; p=0·5840). INTERPRETATION A dual pathway antithrombotic therapy approach combining low-dose rivaroxaban with a P2Y12 inhibitor for the treatment of patients with acute coronary syndromes had similar risk of clinically significant bleeding as aspirin and a P2Y12 inhibitor. A larger, adequately powered trial would be required to definitively assess the efficacy and safety of this approach. FUNDING Janssen Research & Development and Bayer AG.

Comparison of the Efficacy and Safety of Two Rivaroxaban Doses in Acute Coronary Syndrome (from ATLAS ACS 2–TIMI 51)

The dosing of anticoagulants is critical when balancing efficacy and safety. The Anti-Xa Therapy to Lower Cardiovascular Events in Addition to Aspirin With/Without Thienopyridine Therapy in Subjects With Acute Coronary Syndrome 2-Thrombolysis In Myocardial Infarction 51 (ATLAS ACS 2-TIMI 51) trial was designed to evaluate 2 low doses of rivaroxaban compared with placebo in patients with recent acute coronary syndromes being treated with antiplatelet therapies. Because the 2 doses significantly reduced the primary efficacy end point, a further comparison of the 2 treatment strategies was deemed important. In total, 15,526 patients were randomized to twice-daily rivaroxaban 2.5 mg, rivaroxaban 5 mg, or placebo. Comparing the 2 active doses, there were no significant differences between 2.5 and 5 mg for the primary efficacy end point of cardiovascular death, myocardial infarction, or stroke (9.1% vs 8.8%, p = 0.89), myocardial infarction (6.1% vs 4.9%, p = 0.23), or stent thrombosis (2.2% vs 2.3%, p = 0.59). However, there was a divergence in cardiovascular death, which included ischemic and hemorrhagic events, with the 2.5-mg dose resulting in lower rates than the 5-mg dose (2.7% vs 4.0%, p = 0.009). Notably, with 2.5 versus 5 mg, there were fewer study drug discontinuations (p = 0.004) and fewer non-coronary artery bypass grafting TIMI major or minor bleeds (p = 0.021) and fatal bleeds (p = 0.044). Of the patients who died, 8 in the 2.5-mg group and 20 in the 5-mg group experienced non-coronary artery bypass grafting TIMI major or minor bleeding events before death. In conclusion, the 2 doses of rivaroxaban reduced cardiovascular events in patients with recent acute coronary syndromes treated with antiplatelet therapies; however, the 2.5-mg dose was associated with lower mortality and fewer bleeding complications than the 5-mg dose. Thus, the addition of rivaroxaban 2.5 mg twice daily offers a more favorable balance of efficacy and safety in patients with recent acute coronary syndromes.

Pharmacokinetics and pharmacodynamics of rivaroxaban and its effect on biomarkers of hypercoagulability in patients with chronic heart failure

BACKGROUND Heart failure (HF) is associated with a hypercoagulable state that predisposes to thromboembolism and anti-coagulation may improve clinical outcomes. The oral, direct Factor Xa inhibitor, rivaroxaban, has not been studied in patients with HF. We hypothesized that rivaroxaban would also reduce biomarkers of hypercoagulability in patients with HF. METHODS This study consisted of two cohorts: Cohort 1, open-label, actively controlled with enoxaparin 40 mg once daily, included 8 patients with acute decompensated HF; Cohort 2, double-blind and placebo-controlled, included 18 patients with stable, severe New York Heart Association Class III/IV HF. RESULTS The pharmacokinetics (PK) and pharmacodynamics (PD) of rivaroxaban were similar across both cohorts. Biomarker assessments were performed in Cohort 2; prothrombin fragment 1.2 (F1.2) mean concentration decreased by 2.7 ng/ml over 7 days with rivaroxaban, and increased by 11.6 ng/ml with placebo, an absolute difference of 14.3 ng/ml (p = 0.0009). A non-significant reduction in rate of increase of D-dimer (DD) and thrombin-anti-thrombin complex (TAT) levels with rivaroxaban was observed over 7 days (p = 0.31 and p = 0.77, respectively). CONCLUSION Rivaroxaban has similar PK/PD in patients with either acute or chronic HF. In vivo, hypercoagulability biomarkers appear to increase over time. Rivaroxaban reversed this trend for F1.2, and may reduce the rate of increase of DD and TAT in patients with stable, severe HF.

Population pharmacokinetics and pharmacodynamics of rivaroxaban in patients with acute coronary syndromes

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT • Population pharmacokinetics and pharmacodynamics of rivaroxaban have been characterized in healthy subjects and in patients with total venous thromboembolism, deep vein thrombosis or atrial fibrillation. WHAT THIS STUDY ADDS • This article is the first description of the population pharmacokinetics (PK) and pharmacodynamics (PD) of rivaroxaban in patients with acute coronary syndrome (ACS). It is the largest population pharmacokinetic and pharmacodynamic study on rivaroxaban conducted to date (n= 2290). The PK and PK-PD relationship of rivaroxaban in patients with ACS were similar to those in other patient populations. In addition, model-based simulations showed that the influence of renal function and age on the exposure to rivaroxaban in the ACS population were similar to the findings from Phase 1 special population studies. These findings suggest that rivaroxaban has highly predictable PK-PD and may provide a consistent anticoagulant effect across the studied patient populations, which allows an accurate prediction of the dose to control anticoagulation optimally. AIMS The aim of this analysis was to use a population approach to facilitate the understanding of the pharmacokinetics and pharmacodynamics of rivaroxaban in patients with acute coronary syndrome (ACS) and to evaluate the influence of patient covariates on the exposure of rivaroxaban in patients with ACS. METHODS A population pharmacokinetic model was developed using pharmacokinetic samples from 2290 patients in Anti-Xa Therapy to Lower Cardiovascular Events in Addition to Standard Therapy in Subjects with Acute Coronary Syndrome Thrombolysis in Myocardial Infarction 46. The relationship between pharmacokinetics and the primary pharmacodynamic end point, prothrombin time, was evaluated. RESULTS The pharmacokinetics of rivaroxaban in patients with ACS was adequately described by an oral one-compartment model. The estimated absorption rate, apparent clearance and volume of distribution were 1.24 h(-1) (interindividual variability, 139%), 6.48 l h(-1) (31%) and 57.9 l (10%), respectively. Simulations indicate that the influences of renal function, age and bodyweight on exposure in ACS patients are consistent with the findings in previous Phase 1 studies. Rivaroxaban plasma concentrations exhibit a close-to-linear relationship with prothrombin time in the ACS population, with little interindividual variability. The estimated pharmacokinetic and pharmacodynamic parameters for the ACS patients were comparable to those for venous thromboembolism prevention, deep vein thrombosis and atrial fibrillation patients. CONCLUSIONS The similarity in pharmacokinetics/pharmacodynamics of rivaroxaban among different patient populations and the low interindividual variability in the exposure-prothrombin time relationship indicate that the anticoagulant effect of rivaroxaban is highly predictable and consistent across all the patient populations studied.

The effect of rivaroxaban on myocardial infarction in the ATLAS ACS 2 - TIMI 51 trial.

Aims: Rivaroxaban reduces cardiovascular death, myocardial infarction (MI), or stroke in patients following acute coronary syndrome (ACS). We aimed to characterize the specific effects of rivaroxaban on the size and type of MI. Methods: The Anti-Xa Therapy to Lower Cardiovascular Events in Addition to Standard Therapy in Subjects with Acute Coronary Syndrome-Thrombolysis in Myocardial Infarction 51 (ATLAS ACS 2-TIMI 51) study randomized 15,526 patients with a recent ACS to rivaroxaban 2.5 mg BID, rivaroxaban 5 mg BID, or placebo. An independent clinical events committee adjudicated each MI that occurred during the study and further classified them based on type. Data are presented as two-year Kaplan-Meier event rates and hazard ratios (HRs) and 95% confidence intervals (CI). Results: In total, 665 patients experienced a post-randomization MI. The majority (n=535, 80.5%) were spontaneous (Type 1) events. Rivaroxaban reduced spontaneous MI when compared with placebo (4.4% vs 5.7%, HR 0.80, 95% 0.67–0.95, p=0.01), and there were directionally consistent reductions with both the 2.5 mg BID (4.7% vs 5.7%, HR 0.84, 95% 0.68–1.02, p=0.08) and 5 mg BID doses (4.1% vs 5.7%, HR 0.77, 95% 0.62–0.94, p=0.01) as compared with placebo. Rivaroxaban reduced MI with large elevations in troponin or creatine kinase-MB (CK-MB) fraction (1.8% vs 2.4%, HR 0.73, 95% CI 0.56–0.96, p=0.03) and STEMI events (1.7% vs 2.5%, HR 0.74, 95% CI 0.56–0.99, p=0.04). Conclusions: In patients stabilized and followed after ACS, the majority of MIs that occur are spontaneous and rivaroxaban significantly reduced the incidence of these events. Notably, rivaroxaban reduced MIs with extensive biomarker release and ST-segment elevation.

The treatment of missing data in a large cardiovascular clinical outcomes study

Background: The potential impact of missing data on the results of clinical trials has received heightened attention recently. A National Research Council study provides recommendations for limiting missing data in clinical trial design and conduct, and principles for analysis, including the need for sensitivity analyses to assess robustness of findings to alternative assumptions about the missing data. A Food and Drug Administration advisory committee raised missing data as a serious concern in their review of results from the ATLAS ACS 2 TIMI 51 study, a large clinical trial that assessed rivaroxaban for its ability to reduce the risk of cardiovascular death, myocardial infarction or stroke in patients with acute coronary syndrome. This case study describes a variety of measures that were taken to address concerns about the missing data. Methods: A range of analyses are described to assess the potential impact of missing data on conclusions. In particular, measures of the amount of missing data are discussed, and the fraction of missing information from multiple imputation is proposed as an alternative measure. The sensitivity analysis in the National Research Council study is modified in the context of survival analysis where some individuals are lost to follow-up. The impact of deviations from ignorable censoring is assessed by differentially increasing the hazard of the primary outcome in the treatment groups and multiply imputing events between dropout and the end of the study. Tipping-point analyses are described, where the deviation from ignorable censoring that results in a reversal of significance of the treatment effect is determined. A study to determine the vital status of participants lost to follow-up was also conducted, and the results of including this additional information are assessed. Results: Sensitivity analyses suggest that findings of the ATLAS ACS 2 TIMI 51 study are robust to missing data; this robustness is reinforced by the follow-up study, since inclusion of data from this study had little impact on the study conclusions. Conclusion: Missing data are a serious problem in clinical trials. The methods presented here, namely, the sensitivity analyses, the follow-up study to determine survival of missing cases, and the proposed measurement of missing data via the fraction of missing information, have potential application in other studies involving survival analysis where missing data are a concern.

Safety and efficacy of rivaroxaban for the secondary prevention following acute coronary syndromes among biomarker-positive patients: Insights from the ATLAS ACS 2-TIMI 51 trial

Background: Despite dual antiplatelet therapy, persistent thrombin generation and thrombin-mediated platelet activation account in part for the residual risk of atherothrombotic disease among patients with prior acute coronary syndrome (ACS). Inhibition of thrombin generation among high-risk ACS patients (biomarker-positive ACS) with the factor Xa inhibitor rivaroxaban may limit ongoing thrombus formation and myocardial necrosis and thereby improve clinical outcomes. Objectives and methods: ATLAS ACS 2-TIMI 51 was a double-blind, placebo-controlled clinical trial that randomized ACS patients to either rivaroxaban 2.5 mg b.i.d., rivaroxaban 5 mg b.i.d., or placebo plus standard-of-care antiplatelet therapy for a mean of 13.1 months and up to 31 months (N=15,526). This post-hoc analysis evaluates the safety and efficacy of rivaroxaban among biomarker-positive ACS patients with and without a history of prior stroke of transient ischemic attack in the ATLAS ACS 2-TIMI 51 trial. Results: A total of 12,626 biomarker-positive ACS patients were included in this analysis. Among biomarker-positive patients without a prior history of stroke or transient ischemic attack, rivaroxaban 2.5 b.i.d. was associated with a reduction in the primary efficacy endpoint (composite of cardiovascular death, myocardial infarction, or stroke) as compared with placebo (hazard ratio=0.80, 95% confidence interval (0.68–0.94), p=0.007) at the expense of an increase in non-coronary-artery-bypass-graft-related Thrombolysis in Myocardial Infarction major bleeding (1.9% vs. 0.7%, p<0.0001), but not a significant increase in either intracranial hemorrhage (0.4% vs. 0.2%, p=0.11) or fatal bleeding (0.1% vs. 0.3%, p=0.16). Conclusion: Rivaroxaban 2.5 mg b.i.d. was associated with a significant reduction in the composite of cardiovascular death, myocardial infarction, or stroke with no increase in fatal bleeding. Biomarker-positive patients with no prior history of stroke or transient ischemic attack may be a optimal target population to receive “dual pathway” therapy with rivaroxaban plus dual antiplatelet therapy for secondary prevention following ACS.

D-Dimer Levels and Effect of Rivaroxaban on Those Levels and Outcomes in Patients With Acute Coronary Syndrome (An ATLAS ACS-TIMI 46 Trial Substudy)

D-dimer has been used as both a diagnostic and prognostic biomarker in the assessment of patients with venous thromboembolism, but its prognostic value in the setting of arterial acute coronary syndromes (ACS) and the ability of pharmacotherapy to reduce D-dimer in ACS is less well characterized. It was hypothesized that elevated baseline D-dimer would be associated with poor clinical outcomes in ACS, and that Factor Xa inhibition with Rivaroxaban would reduce D-dimer acutely and chronically. The ATLAS ACS TIMI-46 trial assessed the safety and efficacy of rivaroxaban compared with placebo in ACS patients. A subset of subjects had a D-dimer measured at baseline (n = 1,834, 52.5%). A univariate and multivariable logistic regression assessed the relation between baseline D-dimer and a composite end point of cardiovascular death, myocardial infarction, or stroke through 6 months. The Wilcoxon rank sum test was used to compare change in D-dimer level between the treatment groups from baseline. Baseline D-dimer was associated with the composite efficacy outcome in a univariate logistic regression (odds ratio 1.15, 95% confidence interval 1.03 to 1.29, p = 0.015) and a multivariable logistic regression (odds ratio 1.13, 95% confidence interval 1.00 to 1.28, p = 0.048). Rivaroxaban administration lowered D-dimer levels compared wth placebo after administration of the first dose of study drug (p = 0.026), at day 30 (p < 0.001) and day 180 (p < 0.001). In conclusion, elevated baseline D-dimer was associated with an increased risk of the composite outcome within 6 months of the ACS event and administration of the Factor Xa inhibitor rivaroxaban was associated with lower D-dimer levels compared with placebo after the first dose, at day 30 and day 180.