Causes of death in patients with atrial fibrillation anticoagulated with rivaroxaban: a pooled analysis of XANTUS.

AIMS: Anticoagulation can prevent stroke and prolong lives in patients with atrial fibrillation (AF). However, anticoagulated patients with AF remain at risk of death. The aim of this study was to investigate the causes of death and factors associated with all-cause and cardiovascular death in the XANTUS population. METHODS AND RESULTS: Causes of death occurring within a year after rivaroxaban initiation in patients in the XANTUS programme studies were adjudicated by a central adjudication committee and classified following international guidance. Baseline characteristics associated with all-cause or cardiovascular death were identified. Of 11 040 patients, 187 (1.7%) died. Almost half of these deaths were due to cardiovascular causes other than bleeding (n = 82, 43.9%), particularly heart failure (n = 38, 20.3%) and sudden or unwitnessed death (n = 24, 12.8%). Fatal stroke (n = 8, 4.3%), which was classified as a type of cardiovascular death, and fatal bleeding (n = 17, 9.1%) were less common causes of death. Independent factors associated with all-cause or cardiovascular death included age, AF type, body mass index, left ventricular ejection fraction, hospitalization at baseline, rivaroxaban dose, and anaemia. CONCLUSION: The overall risk of death due to stroke or bleeding was low in XANTUS. Anticoagulated patients with AF remain at risk of death due to heart failure and sudden death. Potential interventions to reduce cardiovascular deaths in anticoagulated patients with AF require further investigation, e.g. early rhythm control therapy and AF ablation. TRIAL REGISTRATION NUMBERS: NCT01606995, NCT01750788, NCT01800006.

Real-world vs. randomized trial outcomes in similar populations of rivaroxaban-treated patients with non-valvular atrial fibrillation in ROCKET AF and XANTUS.

AIMS: Based on Phase III data, non-vitamin K antagonist oral anticoagulants are recommended for stroke prevention in patients with atrial fibrillation. To determine whether trial outcomes translate into similar event rates in unselected patients, this analysis compared outcomes from the real-world XANTUS study with those from the Phase III ROCKET AF study. METHODS AND RESULTS: Individual patient data from 4020 XANTUS patients were re-weighted to match the proportion of selected baseline characteristics in 7061 rivaroxaban-treated patients from ROCKET AF, using the matching-adjusted indirect comparison (MAIC) method. For the primary analysis, CHADS2 scores and gender were selected as relevant variables. Adjusted annualized incidence rates for XANTUS were calculated and compared with incidence rates from ROCKET AF-the ratio of these rates ('MAIC ratio') was used as a relative effect estimate. Rates of major bleeding [3.10%/year vs. 3.60%/year; MAIC ratio 0.86; 95% confidence interval (CI) 0.67-1.12] and stroke/non-central nervous system systemic embolism (1.54%/year vs. 1.70%/year; MAIC ratio 0.91; 95% CI 0.62-1.32) were similar between XANTUS and ROCKET AF. The rate of all-cause death was higher in XANTUS (3.22%/year vs. 1.87%/year; MAIC ratio 1.72; 95% CI 1.31-2.27), but the rates of vascular death were similar (1.83%/year vs. 1.53%/year; MAIC ratio 1.19; 95% CI 0.84-1.70). Sensitivity analyses weighted by different baseline characteristics supported these results. CONCLUSION: The low rates of major bleeding and stroke in XANTUS were consistent with results from ROCKET AF. All-cause death, but not vascular death, was higher in XANTUS, as expected in an unselected real-world population.

Outcomes after catheter ablation and cardioversion in patients with non-valvular atrial fibrillation: results from the prospective, observational XANTUS study.

Aims: In patients with atrial fibrillation, catheter ablation and cardioversion carry a risk of peri-procedural thromboembolic events; current guidelines recommend anticoagulation in these settings. This study aimed to report the baseline demographics and clinical characteristics of patients enrolled in the prospective, observational XANTUS study who underwent catheter ablation or cardioversion, and adverse outcomes with each of these procedures in patients treated with rivaroxaban. Methods and results: Data collected included information on catheter ablation and cardioversion, and adverse outcomes occurring within 30 days of these procedures: incidence of treatment-emergent adjudicated symptomatic thromboembolic events and major bleeding; and cardiovascular and all-cause death. Incidence of these adverse outcomes at 42 days after cardioversion was also analysed. Patients undergoing either procedure had significantly lower mean CHA2DS2-VASc and HAS-BLED scores than those who did not, and were more frequently hospitalized at study baseline. Within a period of 30 days after intervention, symptomatic thromboembolic events were reported in 1.2% and 0.6% of patients undergoing ablation or cardioversion, respectively; major bleeding events were reported in 2.9% and 0.4% of patients undergoing ablation or cardioversion, respectively. No patients died within 30 days of intervention. Incidence of symptomatic thromboembolic and major bleeding events remained low at 42 days after cardioversion. Conclusion: Similar to the results of prospective and non-interventional studies, the low rates of symptomatic thromboembolic events and major bleeding in patients with atrial fibrillation undergoing ablation or cardioversion and treated with rivaroxaban in XANTUS suggest that its use is associated with an acceptable benefit-risk profile in this setting. Trial registration number: Clinicaltrials.gov: NCT01606995.

XANTUS: a real-world, prospective, observational study of patients treated with rivaroxaban for stroke prevention in atrial fibrillation.

AIMS: Although non-vitamin K antagonist oral anticoagulants are recommended for stroke prevention in patients with non-valvular atrial fibrillation (NVAF) based on clinical trial results, there is a need for safety and efficacy data from unselected patients in everyday clinical practice. XANTUS investigated the safety and efficacy of the Factor Xa inhibitor rivaroxaban in routine clinical use in the NVAF setting. METHODS AND RESULTS: Consecutive consenting patients with NVAF newly started on rivaroxaban were eligible and were followed up at ∼3-month intervals for 1 year, or for at least 30 days after permanent discontinuation. All adverse events (AEs) were recorded as AEs or serious AEs; major outcomes (including major bleeding, symptomatic thromboembolic events [stroke, systemic embolism, transient ischaemic attack, and myocardial infarction], and all-cause death) were centrally adjudicated. There were 6784 patients treated with rivaroxaban at 311 centres in Europe, Israel, and Canada. Mean patient age was 71.5 years (range 19-99), 41% were female, and 9.4% had documented severe or moderate renal impairment (creatinine clearance <50 mL/min). The mean CHADS2 and CHA2DS2-VASc scores were 2.0 and 3.4, respectively; 859 (12.7%) patients had a CHA2DS2-VASc score of 0 or 1. The mean treatment duration was 329 days. Treatment-emergent major bleeding occurred in 128 patients (2.1 events per 100 patient-years), 118 (1.9 events per 100 patient-years) died, and 43 (0.7 events per 100 patient-years) suffered a stroke. CONCLUSION: XANTUS is the first international, prospective, observational study to describe the use of rivaroxaban in a broad NVAF patient population. Rates of stroke and major bleeding were low in patients receiving rivaroxaban in routine clinical practice. TRIAL REGISTRATION NUMBER: Clinicaltrials.gov: NCT01606995.

Uninterrupted rivaroxaban vs. uninterrupted vitamin K antagonists for catheter ablation in non-valvular atrial fibrillation.

AIMS: VENTURE-AF is the first prospective randomized trial of uninterrupted rivaroxaban and vitamin K antagonists (VKAs) in patients with non-valvular atrial fibrillation (NVAF) undergoing catheter ablation (CA). METHODS AND RESULTS: Trial size was administratively set at 250, the protocol-specified target. Events were independently and blindly adjudicated. We randomly assigned 248 NVAF patients to uninterrupted rivaroxaban (20 mg once-daily) or to an uninterrupted VKA prior to CA and for 4 weeks afterwards. The primary endpoint was major bleeding events after CA. Secondary endpoints included thromboembolic events (composite of stroke, systemic embolism, myocardial infarction, and vascular death) and other bleeding or procedure-attributable events. Patients were 59.5 ± 10 years of age, 71% male, 74% paroxysmal AF, and had a CHA2DS2-VASc score of 1.6. The average total heparin dose used to manage activated clotting time (ACT) was slightly higher (13 871 vs. 10 964 units; P < 0.001) and the mean ACT level attained slightly lower (302 vs. 332 s; P < 0.001) in rivaroxaban and VKA arms, respectively. The incidence of major bleeding was low (0.4%; 1 major bleeding event). Similarly, thromboembolic events were low (0.8%; 1 ischemic stroke and 1 vascular death). All events occurred in the VKA arm and all after CA. The number of any adjudicated events (26 vs. 25), any bleeding events (21 vs. 18), and any other procedure-attributable events (5 vs. 5) were similar. CONCLUSION: In patients undergoing CA for AF, the use of uninterrupted oral rivaroxaban was feasible and event rates were similar to those for uninterrupted VKA therapy. NAME OF THE TRIAL REGISTRY: Clinicaltrials.gov trial registration number is NCT01729871.

Complication rates after hip or knee arthroplasty in morbidly obese patients.

BACKGROUND: Morbid obesity has been shown to be a risk factor for increased complications after THA and TKA; however, large studies that would determine the effect size are lacking. QUESTIONS/PURPOSES: The purposes of this study were to determine whether morbid obesity increased the risk of: (1) venous thromboembolism (VTE), (2) bleeding, (3) other adverse events, and (4) infections during the early postoperative period (up to 6 to 8 weeks) after THA or TKA? METHODS: Data from the REgulation of Coagulation in ORthopaedic surgery to prevent Deep vein thrombosis and pulmonary embolism (RECORD) clinical trial program of rivaroxaban for prevention of VTE after THA or TKA were analyzed retrospectively. Data for 12,355 patients were reviewed to identify complication rates in morbidly obese patients (BMI≥40 kg/m2) compared with patients with a BMI less than 40 kg/m2. Explorative analyses compared the rates of asymptomatic deep vein thrombosis (DVT), symptomatic DVT, symptomatic pulmonary embolism, bleeding, and other adverse events by BMI group. RESULTS: There were no significant differences in asymptomatic DVT, symptomatic DVT, symptomatic pulmonary embolism, or bleeding, but there were increases in other adverse events (including receipt of blood transfusion, erythema, peripheral edema, diarrhea, gastrointestinal or abdominal pain) and infections (including respiratory tract or lung infections, wound inflammation or infection, and extrasurgical-site infections), in patients with a BMI of 40 kg/m2 or greater compared with patients with a BMI less than 40 kg/m2. CONCLUSIONS: After THA or TKA, morbid obesity is not associated with an increased risk of VTE or bleeding but is associated with increased early postoperative complications, including erythema, peripheral edema, diarrhea and gastrointestinal or abdominal pain, wound inflammation or infection, extrasurgical-site infections, and respiratory tract or lung infections. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Impact of Modifiable Bleeding Risk Factors on Major Bleeding in Patients With Atrial Fibrillation Anticoagulated With Rivaroxaban.

Background Reducing major bleeding events is a challenge when managing anticoagulation in patients with atrial fibrillation. This study evaluated the impact of modifiable and nonmodifiable bleeding risk factors in patients with atrial fibrillation receiving rivaroxaban and estimated the impact of risk factor modification on major bleeding events. Methods and Results Modifiable and nonmodifiable risk factors associated with major bleeding events were identified from the XANTUS (Xarelto for Prevention of Stroke in Patients With Atrial Fibrillation) prospective registry data set (6784 rivaroxaban-treated patients). Parameters showing univariate association with bleeding were used to construct a multivariable model identifying independent risk factors. Modeling was used to estimate attributed weights to risk factors. Heavy alcohol use (hazard ratio [HR]=2.37; 95% CI 1.24-4.53); uncontrolled hypertension (HR after parameter-wise shrinkage=1.79; 95% CI 1.05-3.05); and concomitant treatment with antiplatelets, nonsteroidal anti-inflammatory drugs, or paracetamol (HR=1.80; 95% CI 1.24-2.61) were identified as modifiable, independent bleeding risk factors. Increasing age (HR=1.25 [per 5-year increment]; 95% CI 1.12-1.38); heart failure (HR=1.97; 95% CI 1.36-2.86); and vascular disease (HR=1.91; 95% CI 1.32-2.77) were identified as nonmodifiable bleeding risk factors. Overall, 128 (1.9%) patients experienced major bleeding events; of these, 11% had no identified bleeding risk factors, 50% had nonmodifiable bleeding risk factors only, and 39% had modifiable bleeding risk factors (with or without nonmodifiable risk factors). The presence of 1 modifiable bleeding risk factor doubled the risk of major bleeding. Conclusions Elimination of modifiable bleeding risk factors is a potentially effective strategy to reduce bleeding risk in atrial fibrillation patients receiving rivaroxaban. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT01606995.

Outcomes associated with non-recommended dosing of rivaroxaban: results from the XANTUS study.

AIMS: In Europe, the approved rivaroxaban dose for stroke prevention in patients with atrial fibrillation (AF) is 20 mg once daily (o.d.), with 15 mg o.d. recommended in patients with creatinine clearance (CrCl) 15-49 mL/min. Non-recommended doses are prescribed in real-world practice. This analysis of the XANTUS study assessed outcomes associated with non-recommended dosing and patient characteristics that may have impacted dose choice. METHODS AND RESULTS: Baseline characteristics and 1 year outcomes were compared in 4464/6784 patients with known CrCl, receiving recommended or non-recommended rivaroxaban doses; 3608 (80.8%) patients received recommended doses (mean CHADS2 score 1.9) and 856 (19.2%) non-recommended doses (mean CHADS2 score 2.5). Incidence rate (events/100 patient-years) for the composite of treatment-emergent adjudicated major bleeding, stroke/systemic embolism, and death was 7.5 [95% confidence interval (CI) 5.7-9.8] and 4.8 (95% CI 4.1-5.7) with non-recommended and recommended doses, respectively [hazard ratio (HR) 1.55, 95% CI 1.2-2.1; P = 0.004]. Incidence rates for the components of the composite were 3.7 and 2.6, 1.4 and 0.9, and 3.5 and 1.9, respectively. Adjustment for baseline characteristics showed similar rates of the composite outcome (HR 1.06, 95% CI 0.77-1.45; P = 0.719). Multivariable analysis identified age, anaemia, congestive heart failure, diabetes mellitus, CrCl, lower body weight, AF type, and vascular disease as predictors of non-recommended dosing. CONCLUSION: Non-recommended rivaroxaban dosing was associated with less favourable outcomes, possibly due to baseline characteristics, in addition to renal function, that may also affect physicians' dosing decisions. TRIAL REGISTRATION NUMBER: Clinicaltrials.gov: NCT01606995.

Global Prospective Safety Analysis of Rivaroxaban.

BACKGROUND: The efficacy of direct oral anticoagulants (DOACs) for stroke prevention in patients with atrial fibrillation (AF) has been established in clinical trials. However, well-conducted, prospective, real-world observational studies of the safety and effectiveness of DOACs are needed. OBJECTIVES: This study sought to assess the real-world safety profile of rivaroxaban through a pooled analysis of patients with AF enrolled in the XANTUS (Xarelto for Prevention of Stroke in Patients With Atrial Fibrillation) program worldwide. METHODS: A pre-planned pooled analysis of the XANTUS, XANAP (Xarelto for Prevention of Stroke in Patients With Atrial Fibrillation in Asia), and XANTUS-EL (Xarelto for Prevention of Stroke in Patients With Atrial Fibrillation in Latin America and EMEA Region) registries was performed. Patients with AF newly starting rivaroxaban for stroke prevention were followed for 1 year. Primary outcomes were treatment-emergent major bleeding, adverse events (AEs)/serious AEs, and all-cause death. Secondary outcomes included treatment-emergent thromboembolic events and nonmajor bleeding. Major outcomes were centrally adjudicated. RESULTS: Overall, 11,121 patients were included (mean age 70.5 ± 10.5 years; female 42.9%). Comorbidities included heart failure (21.2%), hypertension (76.2%), and diabetes (22.3%). Event rates were: events/100 patient-years: major bleeding 1.7 (95% confidence interval [CI]: 1.5 to 2.0; lowest: Latin America 0.7; highest: Western Europe, Canada, and Israel 2.3); all-cause death 1.9 (95% CI: 1.6 to 2.2; lowest: Eastern Europe 1.5; highest: Latin America, Middle East, and Africa 2.7); and stroke or systemic embolism 1.0 (95% CI: 0.8 to 1.2; lowest: Latin America 0; highest: East Asia 1.8). One-year treatment persistence was 77.4% (lowest: East Asia 66.4%; highest: Eastern Europe 84.4%). CONCLUSIONS: This large, prospective, real-world analysis in 11,121 patients from 47 countries showed low bleeding and stroke rates in rivaroxaban-treated patients with AF, with low treatment discontinuation in different regions of the world. Results were broadly consistent across regions. (Xarelto for Prevention of Stroke in Patients With Atrial Fibrillation [XANTUS]; NCT01606995; Xarelto for Prevention of Stroke in Patients With Atrial Fibrillation in Latin America and EMEA Region [XANTUS-EL]; NCT01800006; and Xarelto for Prevention of Stroke in Patients With Atrial Fibrillation in Asia [XANAP]; NCT01750788).

Impact of Switching From a Vitamin K Antagonist to Rivaroxaban on Satisfaction With Anticoagulation Therapy: The XANTUS-ACTS Substudy.

BACKGROUND: The efficacy, safety, and ease of use of rivaroxaban may reduce anticoagulation-treatment burden and improve nonvalvular atrial fibrillation (NVAF) patient satisfaction compared with vitamin K antagonists (VKAs). HYPOTHESIS: Transitioning from a VKA to rivaroxaban improves treatment satisfaction in routine practice. METHODS: Xarelto for Prevention of Stroke in Patients With Atrial Fibrillation (XANTUS) is a prospective, noninterventional study in patients with NVAF prescribed rivaroxaban for prevention of stroke in routine practice. Patients receiving a VKA 4 weeks prior to the initial XANTUS study visit and switched to rivaroxaban were asked to complete the Anti-Clot Treatment Scale (ACTS). Changes from the initial visit to the first follow-up visit at ∼ 3 months (corresponding to a comparison of rivaroxaban vs prior VKA) for ACTS burden and benefit scores were calculated using and reported as least squared mean differences (LSMDs) with 95% confidence intervals (CIs). RESULTS: The study included 1291 NVAF patients with prior VKA treatment. The mean baseline ACTS burden and benefit scores were 50.51 ± 8.42 and 10.30 ± 2.70, respectively. After ∼ 3 months of rivaroxaban treatment, LSMDs were 4.38 points (95% CI: 2.53-6.22, P < 0.0001) for the burden and 1.01 points (95% CI: 0.27-1.75, P = 0.0075) for the benefit score. Fifty-four percent and 48% of patients reported experiencing at least a minimally important clinical difference in burden and benefit scores, respectively. CONCLUSIONS: Within this XANTUS cohort, switching from a VKA to rivaroxaban yielded statistically and clinically significant improvements in ACT burden and benefit scores.

XANTUS: rationale and design of a noninterventional study of rivaroxaban for the prevention of stroke in patients with atrial fibrillation.

Atrial fibrillation (AF) is associated with a fivefold increase in the risk of stroke. The Phase III ROCKET AF (Rivaroxaban Once-Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation) trial showed that rivaroxaban, an oral, direct Factor Xa inhibitor, was noninferior to warfarin for the reduction of stroke or systemic embolism in patients with AF. Compared with warfarin, rivaroxaban significantly reduced rates of intracranial and fatal hemorrhages, although not rates of bleeding overall. XANTUS (Xarelto(®) for Prevention of Stroke in Patients with Atrial Fibrillation) is a prospective, international, observational, postauthorization, noninterventional study designed to collect safety and efficacy data on the use of rivaroxaban for stroke prevention in AF in routine clinical practice. The key goal is to determine whether the safety profile of rivaroxaban established in ROCKET AF is also observed in routine clinical practice. XANTUS is designed as a single-arm cohort study to minimize selection bias, and will enroll approximately 6,000 patients (mostly from Europe) with nonvalvular AF prescribed rivaroxaban, irrespective of their level of stroke risk. Overall duration of follow-up will be 1 year; the first patient was enrolled in June 2012. Similar studies (XANTUS-EL [Xarelto(®) for Prevention of Stroke in Patients with Nonvalvular Atrial Fibrillation, Eastern Europe, Middle East, Africa and Latin America] and XANAP [Xarelto(®) for Prevention of Stroke in Patients with Atrial Fibrillation in Asia-Pacific]) are ongoing in Latin America and Asia-Pacific. Data from these studies will supplement those from ROCKET AF and provide practical information concerning the use of rivaroxaban for stroke prevention in AF.

Rationale and design of VENTURE-AF: a randomized, open-label, active-controlled multicenter study to evaluate the safety of rivaroxaban and vitamin K antagonists in subjects undergoing catheter ablation for atrial fibrillation.

PURPOSE: To evaluate the safety of uninterrupted rivaroxaban, a novel oral anticoagulant that directly inhibits factor Xa, and a vitamin K antagonist (VKA) in eligible adult patients with nonvalvular AF (NVAF) who are scheduled for a catheter ablation. METHODS/DESIGN: This is a prospective, randomized, open-label, active-controlled, global multicenter safety study of up to 250 randomized patients. Eligible patients with paroxysmal or persistent NVAF, a left ventricular ejection fraction >40 %, and a creatinine clearance >50 mL/min will be randomized 1:1 to rivaroxaban 20 mg orally once daily or to dose-adjusted oral VKA (recommended international normalized ratio (INR) 2.0-3.0) and stabilized on anticoagulation therapy for 1-7 days (if no intracardiac thrombus on transesophageal echocardiogram (TEE) immediately prerandomization/post-randomization or if 3 weeks of sufficient anticoagulation is documented) or for 4-5 weeks (if no TEE, no documented 3 weeks of sufficient anticoagulation, or by patient choice). During catheter ablation, heparin will be administered (ACT-targeted range = 300-400 s) after catheter ablation, and VKA will be managed per usual care. The next dose of rivaroxaban will be provided at least 6 h after establishment of hemostasis. The primary endpoint will be the incidence of post-procedure major bleeding events observed during the first 30 ± 5 days post-ablation. Secondary endpoints will include post-procedure thromboembolic events, additional bleeding, time-to-event, and medication adherence. RELEVANCE: This study is intended to provide information about the safety characteristics of rivaroxaban in patients with NVAF undergoing catheter ablation.