Rivaroxaban and Aspirin in Peripheral Vascular Disease: a Review of Implementation Strategies and Management of Common Clinical Scenarios

Intravascular Ultrasound Guidance During Peripheral Vascular Interventions: Long-term Clinical Outcomes and Costs From the Japanese Perspective

PURPOSE

The value of intravascular ultrasound (IVUS) guidance during peripheral vascular revascularization procedures is incompletely understood. Moreover, data on long-term clinical outcomes and costs are limited. The objective of this study was to compare outcomes and costs between IVUS and contrast angiography alone in patients undergoing peripheral revascularization procedures in Japan.

MATERIALS AND METHODS

This retrospective comparative analysis was performed using the Japanese Medical Data Vision insurance claims database. All patients undergoing revascularization for peripheral artery disease (PAD) between April 2009 and July 2019 were included. Patients were followed until July 2020, death, or a subsequent revascularization procedure for PAD. Two patient groups were compared: one undergoing IVUS imaging or the other contrast angiography alone. The primary end point was major adverse cardiac and limb events, including all-cause-mortality, endovascular thrombolysis, subsequent revascularization procedures for PAD, stroke, acute myocardial infarction, and major amputations. Total health care costs were documented over the follow-up and compared between groups, using a bootstrap method.

RESULTS

The study included 3956 patients in the IVUS group and 5889 in the angiography alone group. Intravascular ultrasound was significantly associated with reduced risk of a subsequent revascularization procedure (adjusted hazard ratio: 0.25 [0.22-0.28]) and major adverse cardiac and limb events (0.69 [0.65-0.73]). The total costs were significantly lower in the IVUS group, with a mean cost saving over follow-up of $18 173 [$7 695-$28 595] per patient.

CONCLUSION

The use of IVUS during peripheral revascularization provides superior long-term clinical outcomes at lower costs compared with contrast angiography alone, warranting wider adoption and fewer barriers to IVUS reimbursement for patients with PAD undergoing routine revascularization.

CLINICAL IMPACT

Intravascular ultrasound (IVUS) guidance during peripheral vascular revascularization has been introduced to improve the precision of the procedure. However, questions over the benefit of IVUS in terms of long-term clinical outcome and over cost have limited its use in everyday clinical practice. This study, performed in a Japanese health insurance claims database, demonstrates that use of IVUS provides a superior clinical outcome over the long term at a lower cost compared to angiography alone. These findings should encourage clinicians to use IVUS in routine peripheral vascular revascularization procedures and encourage providers to reduce barriers to use.

Optimization of the pharmacological therapy in patients with poly-vascular disease: A multidisciplinary approach

The recent shift of the concept of cardiovascular disease as a chronic progressive condition, potentially involving multiple districts, has driven attention to the optimal management of patients with concomitant coronary and peripheral artery disease, representing a subset of patients with an increased risk of events and impaired survival. Recent pharmacological achievements in terms of antithrombotic therapy and lipid-lowering drugs allow multiple therapeutical combinations, thus requiring optimizing the treatment in a tailored fashion according to patients’ risk profiles. Nevertheless, data dedicated to this specific subset of patients are still modest. We summarize currently available strategies and indications for the management of antithrombotic and lipid-lowering drugs in patients with the poly-vascular disease.

Differential Inhibition of Platelet Reactivity by Dual Therapy With Aspirin and Low-Dose Rivaroxaban in Peripheral Arterial Disease: A Pilot Study

Patients with peripheral arterial disease (PAD) benefit from combination therapy with acetylsalicylic acid (ASA, 100 mg, one time per day) plus low-dose rivaroxaban (2.5 mg, two times per day) compared to ASA monotherapy. In particular, major adverse cardiac and limb events were significantly reduced after peripheral endovascular revascularization (EVR). In this pilot study, the platelet activation status in vivo and platelet reactivity in vitro were longitudinally analyzed by flow cytometric assays and calibrated automated thrombography in platelet-rich plasma (PRP) from 10 patients with PAD receiving ASA (100 mg, one time per day) before EVR, ASA plus clopidogrel (75 mg, one time per day) after EVR, and ASA plus rivaroxaban (2.5 mg, two times per day) during a long-term follow-up. Platelet responsiveness to clopidogrel was compared to additional 10 patients with stable PAD and clopidogrel (75 mg, one time per day) monotherapy. ASA plus rivaroxaban treatment resulted in a significantly decreased thrombin peak in PRP for two triggers, namely, low concentration of tissue factor (TF) and thrombin, compared to ASA monotherapy. TF-controlled thrombin generation was additionally characterized by a significantly prolonged lag time in PRP and platelet-free plasma during ASA plus rivaroxaban combination therapy. In comparison, ASA plus clopidogrel treatment presented a significant reduction of the thrombin peak in PRP, which was less pronounced than during subsequent ASA plus rivaroxaban therapy. Platelet responsiveness to clopidogrel was observed for 60% of patients receiving ASA plus clopidogrel and clopidogrel monotherapy, respectively. Blocking of CD36 on the platelet surface further reduced the thrombin peak in PRP induced by TF for all three therapy regimes. Platelet activation in vivo and in response to the GPVI-agonist convulxin or thrombin in vitro was similar, whereas integrin αIIbβ3 activation and α-granule release induced by the PAR-1 activating peptide TRAP-6 were significantly diminished during ASA plus rivaroxaban treatment compared to ASA monotherapy. In conclusion, the data of this pilot study indicate an inhibitory effect of rivaroxaban on the thrombin propagation phase of CD36-sensitive platelet thrombin formation in patients with PAD treated with ASA plus rivaroxaban combination therapy, which is associated with decreased PAR-1 but not thrombin-mediated platelet activation.

Of vascular defense, hemostasis, cancer, and platelet biology: an evolutionary perspective

We have established considerable expertise in studying the role of platelets in cancer biology. From this expertise, we were keen to recognize the numerous venous-, arterial-, microvascular-, and macrovascular thrombotic events and immunologic disorders are caused by severe, acute-respiratory-syndrome coronavirus 2 (SARS-CoV-2) infections. With this offering, we explore the evolutionary connections that place platelets at the center of hemostasis, immunity, and adaptive phylogeny. Coevolutionary changes have also occurred in vertebrate viruses and their vertebrate hosts that reflect their respective evolutionary interactions. As mammals adapted from aquatic to terrestrial life and the heavy blood loss associated with placentalization-based live birth, platelets evolved phylogenetically from thrombocytes toward higher megakaryocyte-blebbing-based production rates and the lack of nuclei. With no nuclei and robust RNA synthesis, this adaptation may have influenced viral replication to become less efficient after virus particles are engulfed. Human platelets express numerous receptors that bind viral particles, which developed from archetypal origins to initiate aggregation and exocytic-release of thrombo-, immuno-, angiogenic-, growth-, and repair-stimulatory granule contents. Whether by direct, evolutionary, selective pressure, or not, these responses may help to contain virus spread, attract immune cells for eradication, and stimulate angiogenesis, growth, and wound repair after viral damage. Because mammalian and marsupial platelets became smaller and more plate-like their biophysical properties improved in function, which facilitated distribution near vessel walls in fluid-shear fields. This adaptation increased the probability that platelets could then interact with and engulf shedding virus particles. Platelets also generate circulating microvesicles that increase membrane surface-area encounters and mark viral targets. In order to match virus-production rates, billions of platelets are generated and turned over per day to continually provide active defenses and adaptation to suppress the spectrum of evolving threats like SARS-CoV-2.

Pharmacological management of obstructive peripheral arterial disease: two case reports

INTRODUCTION

Peripheral artery disease (PAD), also abbreviated as LEAD or lower extremity artery disease, is an important predictor of cardiovascular morbidity and mortality. Rivaroxaban, a selective direct factor Xa inhibitor, is proposed as an additional pharmacologic option for managing this disease.

CASES

Two patients presented with PAD and high-risk comorbidities. The first case showed how the evaluation of the cardiovascular risk guided the therapeutic management of the patient. The second case was about a patient diagnosed with LEAD who experienced worsening from exertional ischemia towards critical ischemia requiring amputation despite distal revascularization, and parenteral vasodilator therapy to relieve pain. This case suggested a comprehensive care management approach, adapted to PAD progression stages.

CONCLUSION

The PAD management consists nowadays of optimizing the management of cardiovascular risk factors and disease progression. Diagnosis, treatment, monitoring and patient education should be handled by a vascular specialist in a specialized care unit.

Catheter-directed intra-arterial thrombolysis in the treatment of acute thrombosis of below-the-knee arteries

Selecting treatment options in acute arterial thrombosis of the lower extremity, which threatens limb viability, is still a challenge for vascular surgeons. Early restoration of blood flow is crucial and is conducted by surgical thrombectomies or endovascular procedures, depending on patient condition. Catheter-directed thrombolysis with or without percutaneous mechanical thrombectomy for acute limb ischemia has been widely implemented from the early 1990s. Here, we present 2 cases of acute thrombosis of below-the-knee arteries, where we successfully saved the involved limbs using catheter-directed thrombolysis and thrombus aspiration.

Efficacy and Safety of Rivaroxaban Therapy for Patients With Peripheral Artery Disease: A Systematic Review and Meta-Analysis

OBJECTIVE

We performed a systematic review and meta-analysis to evaluate the efficacy and safety of rivaroxaban in patients with PAD for the first time.

METHODS

We searched MEDLINE, EMBASE and the Cochrane Library database for randomized controlled trials (RCTs) conducted for PAD.

RESULTS

Three trials which contained 14873 patients were included for final meta-analysis. The results showed patients with rivaroxaban was associated with reduction in primary efficacy outcome (RR 0.83; 95% CI 0.76 to 0.90; p < 0.001). The RR was 0.85 (0.71 to 1.01) for patients with rivaroxaban alone and 0.81 (0.74 to 0.89) for those with rivaroxaban plus aspirin (p for heterogeneity between groups = 0.65). Patients with rivaroxaban showed a lower rate of acute limb ischemia (0.56; 0.47 to 0.66; p < 0.001). There was a trend toward a reduction in the rate of major amputation for vascular causes in the rivaroxaban arm (0.81; 0.63 to 1.03; p = 0.08). Compared with control, rivaroxaban therapy did not reduce the risks of myocardial infarction (0.87, 0.73 to 1.04, p = 0.12), ischemic stroke (0.85, CI 0.68 to 1.06, p = 0.15), death from cardiovascular causes (0.99, 0.85 to 1.15, p = 0.91) or death from any cause (1.00, 0.90 to 1.12, p = 0.98). Rivaroxaban therapy was associated with a 1.57-fold higher major bleeding rate as compared with those with aspirin or warfarin alone.

CONCLUSIONS

Overall, the risks of the primary efficacy outcomes or adverse limb events were significantly lower with rivaroxaban than with aspirin or warfarin alone in patients with PAD. It also points out the significant major bleeding that occur because of such therapies.

Network Meta-Analysis Comparing the Outcomes of Treatments for Intermittent Claudication Tested in Randomized Controlled Trials

Background No network meta-analysis has considered the relative efficacy of cilostazol, home exercise therapy, supervised exercise therapy (SET), endovascular revascularization (ER), and ER plus SET (ER+SET) in improving maximum walking distance (MWD) over short- (<1 year), moderate- (1 to <2 years), and long-term (≥2 years) follow-up in people with intermittent claudication. Methods and Results A systematic literature search was performed to identify randomized controlled trials testing 1 or more of these 5 treatments according to Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. The primary outcome was improvement in MWD assessed by a standardized treadmill test. Secondary outcomes were adverse events and health-related quality of life. Network meta-analysis was performed using the gemtc R statistical package. The Cochrane collaborative tool was used to assess risk of bias. Forty-six trials involving 4256 patients were included. At short-term follow-up, home exercise therapy (mean difference [MD], 89.4 m; 95% credible interval [CrI], 20.9-157.7), SET (MD, 186.8 m; 95% CrI, 136.4-237.6), and ER+SET (MD, 326.3 m; 95% CrI, 222.6-430.6), but not ER (MD, 82.5 m; 95% CrI, -2.4 to 168.2) and cilostazol (MD, 71.1 m; 95% CrI, -24.6 to 167.9), significantly improved MWD (in meters) compared with controls. At moderate-term follow-up, SET (MD, 201.1; 95% CrI, 89.8-318.3) and ER+SET (MD, 368.5; 95% CrI, 195.3-546.9), but not home exercise therapy (MD, 99.4; 95% CrI, -174.0 to 374.9) or ER (MD, 84.2; 95% CrI, -35.3 to 206.4), significantly improved MWD (in meters) compared to controls. At long-term follow-up, none of the tested treatments significantly improved MWD compared to controls. Adverse events and quality of life were reported inconsistently and could not be meta-analyzed. Risk of bias was low, moderate, and high in 4, 24, and 18 trials respectively. Conclusions This network meta-analysis suggested that SET and ER+SET are effective at improving MWD over the moderate term (<2 year) but not beyond this. Durable treatments for intermittent claudication are needed.

Efficacy and safety of non-vitamin K antagonist oral anticoagulants combined with antiplatelet drugs for patients with peripheral artery disease: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The efficacy and safety of non-vitamin K antagonist oral anticoagulants (NOACs) combined with antiplatelet drugs in patients with peripheral artery disease remain largely unknown.

OBJECTIVE

The aim of this meta-analysis was to explore the effects of NOACs combined with antiplatelet drugs versus antiplatelet drugs alone in this population.

METHODS

A comprehensive search of randomized controlled trials published in PubMed, EMBASE, Web of Science, and the Cochrane Library in 30 September 2020 and before. According to the I² statistic, a random or fixed-effect model was used to analyze the safety and effectiveness of NOACs combined with antiplatelet drugs in peripheral artery disease patients.

RESULTS

Three RCTs met the inclusion criteria, with a total sample size of 11,761 participants. Compared with antiplatelet drugs alone, NOACs combined with antiplatelet drugs resulted in lower risk of ischemic stroke events (OR = 0.75, 95%CI 0.57-0.98, p = 0.03), while other treatment effects were not worse than those of single antiplatelet drugs (p ≥ 0.05). In addition, although compared with single antiplatelet drugs alone, NOACs combined with antiplatelet drugs had a higher risk of major bleeding and clinically related nonmajor bleeding, their risk was not higher for intracranial hemorrhage, which may endanger the life of patients, or for fatal bleeding.

CONCLUSIONS

In summary, for peripheral artery disease patients, a combination of NOACs plus antiplatelet drugs may offer additional benefit in reducing ischemic stroke outcome, yet it may increase the risk of bleeding.

Do we have a unified consensus on antithrombotic management of PAD?

Peripheral artery disease (PAD) is one of the most frequent manifestations of atherosclerosis with high rates of morbidity and mortality. Platelets and coagulation are involved in the progression of atherosclerosis and thromboembolic complications. PAD patients have increased prothrombotic potential, which includes platelet hyperaggregability and increased pro-coagulant state. Therefore, antithrombotic treatment is of utmost importance for the prevention of cardiovascular events in this group of patients. Aspirin is the basic antiplatelet drug, but with limited efficacy in PAD. In contrast to coronary artery disease, its effect on the prevention of cardiovascular events in PAD has been limited proven. Particularly in asymptomatic PAD, there is no evidence for risk reduction with aspirin. Clopidogrel and ticagrelor are more effective than aspirin. Clopidogrel is thus an effective alternative to aspirin for prevention of cardiovascular events in symptomatic PAD. In patients who are non-responders to clopidogrel, ticagrelor is indicated. Dual antiplatelet treatment (DAPT) with aspirin and ticagrelor in patients with coronary artery disease and concomitant PAD significantly decreased the rate of major adverse cardiovascular events, including adverse limb events. However, in the CHARISMA Trial, aspirin and clopidogrel were not more effective than aspirin alone and increased bleeding complications. Therefore, DAPT seems effective only in PAD accompanied by coronary artery disease. Anticoagulant treatment for symptomatic PAD with vitamin K antagonists alone or in combination with aspirin is not more effective than single antiplatelet treatment but increases the rate of major bleeding. Low dose rivaroxaban combined with aspirin in PAD patients significantly reduces cardiovascular events, including limb-threatening ischemia and limb amputations. Anticoagulation and antiplatelet treatment after percutaneous or surgical revascularization of PAD improve the patency of treated vessels. Aspirin with or without dipyridamole improved patency of infra-inguinal by-pass grafts at one year. The combination of clopidogrel with aspirin was more effective than aspirin alone in the prevention of prosthetic graft occlusions in patients undergoing below-knee by-pass-grafting. Oral vitamin K antagonists were not more effective than aspirin in the prevention of infra-inguinal by-pass occlusion. The combination of low dose rivaroxaban and aspirin was effective in preventing major adverse cardiovascular events and adverse limb events after infrainguinal endovascular or surgical revascularization in patients with intermittent claudication. However, the data on antithrombotic treatment after revascularization for limb-threatening ischemia is scanty and inconclusive. In conclusion: Antithrombotic treatment of PAD is a cornerstone for the management of these patients. Antiplatelet drugs prevent the initiation and progression of atherosclerosis and are effective also in the prevention of thromboembolic events. Simultaneous use of antiplatelet and anticoagulation drugs is accompanied by an increased risk of bleeding. However, combined treatment with aspirin and low-dose rivaroxaban is more effective than single antithrombotic treatment and safer than full-dose combined treatment.

Rivaroxaban for the prevention of major adverse cardiovascular events in patients with coronary or peripheral artery disease

In the COMPASS trial, the combination of rivaroxaban 2.5 mg twice daily and low-dose aspirin 75-100 mg daily produced a net clinical benefit of 20% in patients with chronic atherosclerotic vascular disease because it reduced major adverse events by 24% and overall mortality by 18% despite an initial increase in major bleeding. In this paper, we examine the rationale for targeting coagulation factor Xa in patients with atherosclerosis, summarize the pharmacology of the 2.5-mg dose, review the trials that led to the approval of the combination of rivaroxaban and aspirin for the long-term management of patients with chronic coronary artery disease or peripheral artery disease and discuss who would benefit the most. We also address the unresolved issues and challenges in the implementation of this therapy.