New directions in the diagnosis and treatment of pulmonary embolism in pregnancy

Specific changes and clinical significance of plasma D-dimer during pregnancy and puerperium: a prospective study

BACKGROUND

Pregnant and puerperal women are high-risk populations for developing venous thromboembolism (VTE). Plasma D-dimer (D-D) is of good value in the diagnosis of exclusion of VTE in the nonpregnant population. Since there is no consensus reference range of plasma D-D applicable to pregnant and puerperal women, the application of plasma D-D is limited. To investigate the change characteristics and the reference range of plasma D-D levels during pregnancy and puerperium and to explore the pregnancy- and childbirth-related factors affecting plasma D-D levels and the diagnostic efficacy of plasma D-D for excluding VTE during early puerperium after caesarean section.

METHODS

A prospective cohort study was conducted with 514 pregnant and puerperal women (cohort 1), and 29 puerperal women developed VTE 24-48 h after caesarean section (cohort 2). In cohort 1, the effects of the pregnancy- and childbirth-related factors on the plasma D-D levels were analyzed by comparing the differences in plasma D-D levels between different groups and between different subgroups. The 95th percentiles were calculated to establish the unilateral upper limits of the plasma D-D levels. The plasma D-D levels at 24-48 h postpartum were compared between normal singleton pregnant and puerperal women in cohort 2 and women from the cesarean section subgroup in cohort 1, binary logistic analysis was used to analyze the relevance between plasma D-D level and the risk of VTE developing 24-48 h after caesarean section, and a receiver operating characteristic (ROC) curve was used to assess the diagnostic efficacy of plasma D-D for excluding VTE during early puerperium after caesarean section.

RESULTS

The 95% reference ranges of plasma D-D levels in the normal singleton pregnancy group were ≤ 1.01 mg/L in the first trimester, ≤ 3.17 mg/L in the second trimester, ≤ 5.35 mg/L in the third trimester, ≤ 5.47 mg/L at 24-48 h postpartum, and ≤ 0.66 mg/L at 42 days postpartum. The plasma D-D levels of the normal twin pregnancy group were significantly higher than those of the normal singleton pregnancy group during pregnancy (P < 0.05), the plasma D-D levels of the GDM group in the third trimester were significantly higher than those of the normal singleton pregnancy group (P < 0.05). The plasma D-D levels of the advanced age subgroup at 24-48 h postpartum were significantly higher than those of the nonadvanced age subgroup (P < 0.05), and the plasma D-D levels of the caesarean section subgroup at 24-48 h postpartum were significantly higher than those of the vaginal delivery subgroup (P < 0.05). The plasma D-D level was significantly correlated with the risk of VTE developing at 24-48 h after caesarean section (OR = 2.252, 95% CI: 1.611-3.149). The optimal cut-off value of plasma D-D for the diagnosis of exclusion of VTE during early puerperium after caesarean section was 3.24 mg/L. The negative predictive value for the diagnosis of exclusion of VTE was 96.1%, and the area under the curve (AUC) was 0.816, P < 0.001.

CONCLUSIONS

The thresholds of plasma D-D levels in normal singleton pregnancy and parturient women were higher than those of nonpregnant women. Plasma D-D had good value in the diagnosis of exclusion of VTE occurring during early puerperium after caesarean section. Further studies are needed to validate these reference ranges and assess the effects of pregnancy- and childbirth-related factors on plasma D-D levels and the diagnostic efficacy of plasma D-D for excluding VTE during pregnancy and puerperium.

The Utilization and Interpretation of Cardiac Biomarkers During Pregnancy: JACC: Advances Expert Panel

Cardiac biomarkers are widely used in the nonpregnant population when acute cardiovascular (CV) pathology is suspected; however, the behavior of these biomarkers in the context of pregnancy is less well understood. Pregnant individuals often have symptoms that mimic those of cardiac dysfunction, and complications of pregnancy may include CV disease. This paper will summarize our current knowledge on the use of cardiac biomarkers in pregnancy and provide suggestions on how to use these tools in clinical practice based on the available evidence. Natriuretic peptides and troponin should not be measured routinely in uncomplicated pregnancy, where values should remain low as in the nonpregnant population. In the context of pre-existing or suspected CV disease, these biomarkers retain their negative predictive value. Elevations of both natriuretic peptides and troponin may occur without clear clinical significance in the immediate postpartum period. Elevations of these markers should always prompt further investigation into possible CV pathology.

Evidence-based perioperative diagnosis and management of pulmonary embolism: A systematic review

Background

The diagnosis and treatment of pulmonary embolism have multi-modal approach based on specificity, sensitivity, availability of the machine, and associated risks of imaging modalities.

Aim

This review aimed to provide shreds of evidence that improve perioperative diagnosis and management of suspected pulmonary embolism.

Methods

The study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline 2020. After a clear criteria has been established an electronic searching database was conducted using PubMed, Google Scholar, Cochrane library, and Cumulative Index of Nursing and Allied Health Literature (CINAHL), with Key search terms included:(‘pulmonary embolism’ AND′ anesthesia management ‘, ‘anticoagulation’ AND ‘pulmonary embolism’, ‘thrombolysis ‘AND ‘pulmonary embolism’, ‘surgery’ AND′ pulmonary embolism’), were used to draw the evidence.

The quality of literatures were categorized based on WHO 2011 level of evidence and degree of recommendation, in addition, the study is registered with research registry unique identifying number (UIN) of reviewregistry1318.” and has high quality based on AMSTAR2 assessment criteria.

Results

A totally of 27 articles were included [guidelines (n = 3), Cochrane (=5), systemic reviews (n = 7), meta-analyses (=2), RCT (n = 4), cohort studies (n = 3), and cross-sectional study (n = 3) and illegible articles identified from searches of the electronic databases were imported into the ENDNOTE software version X7.1 and duplicates were removed.

Discussion

Currently divergent and contradictory approaches are implemented in diagnosis and management for patients suspected of pulmonary embolism.

Conclusion

All perioperative patients, especially trauma victims, prostate or orthopedic surgery, malignancy, immobility, and obesity; smokers; and oral contraceptive users, antipsychotic medications are at increased risk of venous thromboembolism and need special caution during surgery and anesthesia.

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Currently divergent and contradictory approaches are implemented in diagnosis and management for patients suspected of pulmonary embolism.

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This study improves perioperative diagnosis and management of suspected pulmonary embolism patients.

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Patients having trauma, orthopedic surgery, malignancy, immobility; and being smoker; are at risk of VTE and need special caution during surgery.

Pregnancy-adapted YEARS algorithm: can YEARS do more for pregnant women?

Venous thromboembolism (VTE), as a term that encompasses pulmonary embolism (PE) and deep vein thrombosis (DVT), is one of the leading causes of maternal morbidity and mortality [1], especially in developed countries, where PE takes second place after complications of hypertensive disorders [2]. When compared to non-pregnant women of similar age, pregnant women have an approximately four to five times higher risk of VTE [3], with an incidence of 1 in 1000 pregnancies [4]. Approximately 20–25% of VTE cases are caused by PE and 75–80% of cases are caused by DVT [5]. About 60% of DVT occurs antepartum, with the highest risk of antepartum pregnancy-associated VTE being in the third trimester.However, about 60% of PE occurs postpartum [3].

Pregnancy-adapted YEARS algorithm provides high certainty in ruling out pulmonary embolism and high efficiency in reducing the need for CTPAhttp://bit.ly/2GgH4sv

Acute Pulmonary Embolism: Contemporary Approach to Diagnosis, Risk-Stratification, and Management

Pulmonary embolism (PE) affects over 300,000 individuals each year in the United States and is associated with substantial morbidity and mortality. Improvements in the diagnostic performance and availability of computed tomographic pulmonary angiography and D-dimer testing have facilitated the evaluation of patients with suspected PE. High clinical suspicion is required in those with risk factors and/or those that manifest signs or symptoms of venous thromboembolic disease, with validated clinical risk scores such as the Wells and modified Wells score or the PE rule-out criteria helpful in estimating the likelihood for PE. For those with confirmed PE, patients should be categorized and triaged according to the presence or absence of shock or hypotension. Normotensive patients can be further risk-stratified using validated prognostic risk scores, as well as by using imaging and cardiac biomarkers, with those having either signs of right ventricular dysfunction on imaging studies and/or abnormal cardiac biomarkers categorized as being at intermediate-risk and requiring close monitoring and hospital admission. Early discharge and/or home therapy are possible in those that do not manifest any high-risk features. The initial treatment for most patients that are stable consists of anticoagulation, with advanced therapies such as thrombolysis, catheter-based therapies, or surgical embolectomy deferred for those at high risk. Given the heterogeneous presentations of PE and various management strategies available, the development of multidisciplinary PE response teams has emerged to help facilitate decision-making in these patients.

Pregnancy and Pulmonary Embolism

Venous thromboembolism (VTE), referring to both deep vein thrombosis and pulmonary embolism, is a leading cause of death in the developed world during pregnancy. This increased risk is attributed to the Virchow triad, inherited thrombophilias, along with other standard risk factors, and continues for up to 6 to 12 weeks postpartum. During the peripartum period, women should be risk stratified and preventive measures should be initiated based on their risk. Diagnostic tests and treatment strategies commonly used in VTE differ in pregnancy. An understanding of these differences is imperative to diagnose with confidence and to treat appropriately.

Radiologic Aspects of the Diagnosis of Pulmonary Embolism in Pregnancy

Pulmonary embolism in pregnancy is a leading cause of maternal mortality. The clinical presentation is often nonspecific, making imaging essential for accurate diagnosis. After reviewing the literature on the radiologic diagnosis of pulmonary embolism in pregnancy, we concluded that both computed tomography pulmonary angiography and lung perfusion scintigraphy are sensitive with high positive predictive values in the presence of high clinical suspicion, but lung perfusion scintigraphy is recommended given lower maternal breast exposure to ionizing radiation and lower fetal contrast exposure. However, if a chest x-ray is abnormal, computed tomography pulmonary angiography is preferred due to high nondiagnostic rates of lung perfusion scintigraphy.

Clinical 'Pearls' of maternal critical care: part I

PURPOSE OF REVIEW

This review outlines the challenges in looking after pregnant women with thromboembolism and sepsis who either become or are at risk of becoming critically ill during pregnancy.

RECENT FINDINGS

The Pregnancy Mortality Surveillance systems in both the USA and UK record the most common causes of maternal death as thromboembolism and sepsis. Both of these conditions have improved outcomes with timely maternal critical care provided by a multidisciplinary team.

SUMMARY

In this review, we discuss the pathophysiology, diagnosis, and management of thromboembolism and sepsis, two very important conditions with high mortality requiring admission to intensive care.

"Pulmonary embolism diagnostics of pregnant patients: What is the recommended clinical pathway considering the clinical value and associated radiation risks of available imaging tests?"

Pulmonary embolism (PE) during pregnancy remains the leading preventable cause of maternal morbidity and mortality in the developed countries. Diagnosis of PE in pregnant patients is a challenging clinical problem, since pregnancy-related physiologic changes can mimic signs and symptoms of PE. Patient mismanagement may result into unjustified anticoagulant treatment or unnecessary imaging tests involving contrast-related or/and radiation-related risks for both the expectant mother and embryo/fetus. On the other hand, missing or delaying diagnosis of PE could lead to life-threatening conditions for both the mother and the embryo/fetus. Thus, a timely and accurate diagnostic approach is required for the optimal management of pregnant patients with suspected PE. Aim of the current review is to discuss a pregnancy-specific clinical pathway for the early diagnosis of PE with non-ionizing radiation- and ionizing radiation-based imaging modalities taking into account previously reported data on diagnostic value of available imaging tests, and radiation related concerns.

Maternal and pregnancy characteristics affect plasma fibrin monomer complexes and D-dimer reference ranges for venous thromboembolism in pregnancy

BACKGROUND

D-dimers have a high negative predictive value for excluding venous thromboembolism outside of pregnancy but the use in pregnancy remains controversial. A higher cut-off value has been proposed in pregnancy due to a continuous increase across gestation. Fibrin monomer complexes have been considered as an alternative diagnostic tool for exclusion of venous thromboembolism in pregnancy due to their different behavior.

OBJECTIVE

We sought to establish normal values of fibrin monomer complexes and D-dimer as a diagnostic tool for the exclusion of venous thromboembolism in pregnancy and examine the effect of maternal and obstetric factors on these markers.

STUDY DESIGN

Plasma D-dimer and fibrin monomer complexes were measured by quantitative immunoturbidimetry in 2870 women with singleton pregnancies attending their routine first-trimester hospital visit in a prospective screening study for adverse obstetric outcome. Multiple regression analysis was used to determine maternal characteristics and obstetric factors affecting the plasma concentrations and converting these into multiple of the median values after adjusting for significant maternal and obstetric characteristics.

RESULTS

Plasma fibrin monomer complexes increased with maternal weight and were lower in women with a history of cocaine abuse and chronic hypertension. D-dimers increased with gestational age and maternal weight and were higher in sickle cell carriers and in women of African and South Asian racial origin compared to Caucasians.

CONCLUSION

Fibrin monomer complexes and D-dimers are affected by maternal and obstetric characteristics rather than only gestational age. The utility of these fibrin-linked markers as a tool for exclusion of venous thromboembolism in pregnancy might be improved by adjusting for patient-specific characteristics.

Pregnancy outcome after exposure to the novel oral anticoagulant rivaroxaban in women at suspected risk for thromboembolic events: a case series from the German Embryotox Pharmacovigilance Centre

BACKGROUND

New oral anticoagulants are increasingly used in women of childbearing age, but apart from one case report there is no published experience with rivaroxaban exposure during pregnancy.

METHODS

From October 2008 to December 2014, the German Embryotox Pharmacovigilance Centre identified 63 exposed pregnancies among 94 requests concerning rivaroxaban use during childbearing age. Follow-up included paediatric checks until 6 weeks after birth.

RESULTS

All pregnancies with completed follow-up were exposed at least during the first trimester. Treatment indications included venous thromboembolism, knee surgery, and atrial fibrillation. 37 pregnancies were prospectively ascertained and resulted in six spontaneous abortions, eight elective terminations of pregnancy, and 23 live births. All women had discontinued rivaroxaban after recognition of pregnancy, mostly in the first trimester, but in one woman treatment continued until gestational week 26. There was one major malformation (conotruncal cardiac defect) among the 37 prospectively ascertained pregnancies in a woman with complex medication and a previous foetus with cardiac malformation without exposure to rivaroxaban. Only one case of bleeding concerning a retrospective report of surgery for missed abortion was observed in our case series.

CONCLUSION

Our results might give reassurance to those women, who were inadvertently exposed to rivaroxaban in early pregnancy. However, our limited cohort size does not allow ruling out an increased malformation risk and does not support the use of rivaroxaban during pregnancy. In all cases of (inadvertent) rivaroxaban exposure during 1st trimester, anticoagulation regimen should be reconsidered and a detailed ultrasound assessment recommended to confirm normal foetal development.

Aspirin and heparin in pregnancy

INTRODUCTION

A pro-coagulant state during pregnancy can be involved in the occurrence of gestational vascular complications (GVCs) and venous thromboembolism (VTE).

AREAS COVERED

Antithrombotic drugs are used to prevent GVCs and VTE. Aspirin is not efficacious to prevent recurrences in women with previous early loss, while it can prevent pre-eclampsia in some groups of women. Heparins are not effective in the prevention of early recurrent loss and there is uncertainty about their efficacy in women carrying inherited thrombophilias. They could be efficacious in the prevention of GVCs in carriers of inherited thrombophilias, as GVCs have heterogeneous causes, and future studies have to focus on more homogeneous groups of patients. Not enough data are available regarding prophylaxis with heparins to prevent pregnancy-related VTE, but an accurate risk stratification of women during pregnancy and puerperium is crucial for administering prophylaxis in moderate-/high-risk women. Aspirin does not improve live births after assisted reproductive technologies, while heparins increase the number of clinical pregnancies and live births.

EXPERT OPINION

Aspirin is efficacious in the prevention of GVCs in women at risk for pre-eclampsia and in those with antiphospholipid antibodies syndrome. Heparins could give benefit to women at risk for GVCs and/or pregnancy-related VTE.

Pregnancy and venous thromboembolism

PURPOSE OF REVIEW

This review provides a concise and complete overview of diagnostic work-up and treatment of venous thromboembolism in pregnancy, with attention to recent research developments and recent applicable guidelines. This may be useful for all the players of the multidisciplinary interaction needed in this disease management, namely cardiologists and gynecological/obstetric teams.

RECENT FINDINGS

Venous thromboembolism is, in the developed world, a major cause of maternal morbidity and mortality during pregnancy or early after delivery, with a reported incidence ranging from 0.49 to 2.0 events per 1000 deliveries. It is a particularly challenging issue and there is no common consensus on the major themes of this condition. Diagnostic options, prophylaxis and management, in the antenatal, childbirth and postnatal periods, are carefully analyzed in the light of the most recent published data. Besides, old and recent knowledge must be seen through the clinician's skilled and watchful eyes, deciding on a case-to-case and actively contributing in reducing pregnancy-related morbidity.

SUMMARY

Although there is an ongoing debate on various aspects of this condition and there is a paucity of high-quality studies, this review attempts to simplify the complex aspects of joining safety and efficacy in diagnosing and treating a possible two-people life-threatening disease.

Maternal mortality secondary to acute respiratory failure in Colombia: a population-based analysis

PURPOSE

To estimate the mortality rate and trends of respiratory failure in the pregnant and postpartum population of Colombia.

METHODS

A retrospective analysis of the national registry of mortality in Colombia was performed from 1998 to 2009. Maternal death was defined as death that occurred during pregnancy or up to 42 days postpartum. Two independent investigators reviewed maternal deaths to determine deaths caused by respiratory failure. Inter-rater agreement was assessed by kappa correlation coefficient. Causes of respiratory failure were identified according to the International Classification of Diseases (ICD-10).

RESULTS

During the study period, 8,637,486 live births were reported with 6,676 maternal deaths for an overall maternal mortality rate (MMR) of 82.9 per 100,000 live births. Of these, a total of 835 cases were related to respiratory failure, with a specific MMR of 9.69 per 100,000 live births. The main causes of maternal deaths due to respiratory failure included pulmonary sepsis (284 cases, or 3.58 per 100,000 live births), pulmonary embolism (119 cases or 1.50 per 100,000 live births), and preeclampsia-related pulmonary edema (112 cases or 1.41 per 100,000 live births). All-cause maternal mortality ratio decreased yearly from 1998 to 2009 by -3.76% (95% CI -4.83 to -2.67), while the trend of mortality secondary to respiratory failure remained stable over time (P = 0.449).

CONCLUSIONS

Respiratory failure is an important cause of mortality in the obstetric population in Colombia, with pulmonary sepsis as the lead cause of respiratory failure among maternal deaths. While overall maternal mortality rates have decreased in the last decade, respiratory failure-related deaths have remained stable over time.

Intrapartum obstetric management

Maternal cardiac disease complicates approximately 1-2% of all pregnancies in the United States. Just as during the antepartum period, in the immediate period surrounding delivery, obstetrical patients with cardiac disease (both congenital and acquired) will have specialized needs, tailored to the patient and her specific lesion. While the basic principles of labor and delivery management protocols are relevant to this subgroup of patients, there are certain areas in which adjustments must be made. These include endocarditis prophylaxis, recent anticoagulation, fluid management, and the need for increased maternal cardiac monitoring. Awareness of the challenges of the intrapartum period combined with a multi-disciplinary approach from anesthesia, cardiology, and the obstetrical provider will optimize the patient for a safe delivery.

Transfer of dabigatran and dabigatran etexilate mesylate across the dually perfused human placenta

OBJECTIVE

To assess the transplacental pharmacokinetics at term of the oral thrombin inhibitor, dabigatran, and its prodrug, dabigatran etexilate mesylate, to estimate fetal drug exposure.

METHODS

Placentae were obtained with informed consent after cesarean delivery of healthy term pregnancies in Toronto, Ontario, Canada. The transplacental transfer of dabigatran and dabigatran etexilate mesylate was separately assessed using the ex vivo dual perfusion of an isolated human placental cotyledon. Dabigatran, at a concentration of 35 ng/mL, was added to the maternal circulation at the start of the experimental phase. Maternal and fetal samples were taken throughout the preexperimental (1 hour) and experimental (3 hours) phases for measurement of dabigatran and markers of placental viability. Separate placenta perfusions with dabigatran etexilate mesylate were conducted at an initial maternal concentration of 3.5 ng/mL. Dabigatran and dabigatran etexilate mesylate were measured using liquid chromatography-tandem mass spectrometry.

RESULTS

There was slower transfer of dabigatran compared with antipyrine from the maternal-to-fetal circulation, because the median fetal-to-maternal concentration ratio was 0.33 (interquartile range 0.29-0.38) after 3 hours (n=3). The prodrug, dabigatran etexilate mesylate, had limited placental transfer as characterized by a fetal-to-maternal ratio of 0.17 (interquartile range 0.15-0.17) after 3 hours (n=3). Placental viability markers for all perfusions were within normal ranges.

CONCLUSION

This report provides direct evidence of the transfer of dabigatran and its prodrug across the term human placenta from the mother to the fetus. From a clinical perspective, these data suggest that, pending further study, dabigatran should not be used for anticoagulation of pregnant women, because the drug may have an adverse effect on fetal blood coagulation.

The new factor Xa inhibitor: Apixaban

Cardiovascular diseases are still the most important cause of morbidity and mortality worldwide and anti-thrombotic treatment is widely used as a result. The currently used drugs include heparin and its derivatives, vitamin K antagonists, though efficacious, have their own set of limitations like unpredictable pharmacokinetic profile, parenteral route (with heparin and its derivatives only), narrow therapeutic window, and constant laboratory monitoring for their efficacy and safety. This lead to the development of novel factor Xa inhibitors which could be given orally, have predictable dose response relationship and are associated with lesser hemorrhagic complications. They include rivaroxaban, apixaban, and edoxaban among others. Apixaban has currently been approved for use in patients undergoing total knee or hip replacement surgery and to prevent stroke in patients with atrial fibrillation. Many trials are ongoing for apixaban to firmly establish its place in future, among the anti-thrombotic drugs.

Pregnancy-Related Venous Thromboembolism

Pregnancy is associated with an increased risk of venous thromboembolism (VTE), with a reported incidence ranging from 0.49 to 2 events per 1000 deliveries. Risk factors include advanced maternal age, obesity, smoking, and cesarian section. Women with a history of previous VTE are at a 4-fold higher risk of recurrent thromboembolic events during subsequent pregnancies. Additionally, the presence of concomitant thrombophilia, particularly factor V Leiden (homozygosity), prothrombin gene mutation (homozygosity), or antiphospholipid syndrome (APS), increases the risk of pregnancy-related VTE. Low-molecular-weight heparin (LMWH) and unfractionated heparin (UFH) are the drugs of choice for anticoagulation during pregnancy. LMWH is preferred due to ease of use and lower rates of adverse events. Women with high thromboembolic risk particularly those with a family history of VTE should receive antepartum thromboprophylaxis. Women with low thromboembolic risk or previous VTE caused by a transient risk factor (ie, provoked), who have no family history of VTE, may undergo antepartum surveillance. Postpartum anticoagulation can be considered in women with both high and low thromboembolic risk.

The role of rivaroxaban in atrial fibrillation and acute coronary syndromes

Rivaroxaban, a direct factor Xa inhibitor, is a novel oral anticoagulant approved for stroke prevention in patients with nonvalvular atrial fibrillation and also approved in Europe (but not in the United States) to prevent recurrent ischemic events in patients with recent acute coronary syndromes. Advantages of rivaroxaban over oral anticoagulants such as warfarin are the lack of need for ongoing monitoring, a fixed-dose regimen, and fewer drug and food interactions. Drawbacks include a lack of an antidote and the absence of a widely available method to reliably monitor the anticoagulant effect. In patients at risk of stroke due to atrial fibrillation, rivaroxaban was noninferior compared to warfarin in preventing stroke/systemic embolism in the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET-AF) trial and was associated with a similar risk of major bleeding; the incidence of intracranial hemorrhage was 33% lower with rivaroxaban. Concerns raised about the trial were the adequacy of warfarin management and the increase in event rate at the end of the trial. The drug acquisition cost of rivaroxaban is higher than that of warfarin although decision-analytic models suggest that it is cost effective in atrial fibrillation. In patients with recent acute coronary syndrome, low-dose rivaroxaban reduced mortality and the composite end point of death from cardiovascular causes, myocardial infarction and stroke, but this was accompanied by an increased risk of intracranial hemorrhage and major bleeding in the Rivaroxaban in Combination With Aspirin Alone or With Aspirin and a Thienopyridine in Patients With Acute Coronary Syndromes-Thrombolysis in Myocardial Infarction (ATLAS ACS 2-TIMI) 51 trial. Thus, rivaroxaban appears to be a valuable addition to the therapeutic armamentarium in atrial fibrillation although caution should be exercised, given the limited experience in combination with novel oral antiplatelet agents. The role of rivaroxaban as part of a modern regimen in acute coronary syndrome continues to be evaluated.