Limb Outcomes With Ticagrelor Plus Aspirin in Patients With Diabetes Mellitus and Atherosclerosis

BACKGROUND

Ticagrelor reduced major adverse cardiovascular events (MACE) and increased bleeding in patients with type 2 diabetes mellitus (T2DM) and coronary artery disease. Limb events including revascularization, acute limb ischemia (ALI), and amputation are major morbidities in patients with T2DM and atherosclerosis.

OBJECTIVES

This study sought to determine the effect of ticagrelor on limb events.

METHODS

Patients were randomized to ticagrelor or placebo on top of aspirin and followed for a median of 3 years. MACE (cardiovascular death, myocardial infarction, or stroke), limb events (ALI, amputation, revascularization), and bleeding were adjudicated by an independent and blinded clinical events committee. The presence of peripheral artery disease (PAD) was reported at baseline.

RESULTS

Of 19,220 patients randomized, 1,687 (8.8%) had PAD at baseline. In patients receiving placebo, PAD was associated with higher MACE (10.7% vs 7.3%; HR: 1.48; P < 0.001) and limb (9.5% vs 0.8%; HR: 10.67; P < 0.001) risk. Ticagrelor reduced limb events (1.6% vs 1.3%; HR: 0.77; 95% CI: 0.61-0.96; P = 0.022) with significant reductions for revascularization (HR: 0.79; 95% CI: 0.62-0.99; P = 0.044) and ALI (HR: 0.24; 95% CI: 0.08-0.70; P = 0.009). The benefit was consistent with or without PAD (HR: 0.80; 95% CI: 0.58-1.11; and HR: 0.76; 95% CI: 0.55-1.05, respectively; Pinteraction = 0.81). There was no effect modification of ticagrelor vs placebo based on PAD for MACE (Pinteraction = 0.40) or TIMI major bleeding (Pinteraction = 0.3239).

CONCLUSIONS

Patients with T2DM and atherosclerosis are at high risk of limb events. Ticagrelor decreased this risk, but increased bleeding. Future trials evaluating the combination of ticagrelor and aspirin would further elucidate the benefit/risk of such therapy in patients with PAD, including those without coronary artery disease. (A Study Comparing Cardiovascular Effects of Ticagrelor Versus Placebo in Patients With Type 2 Diabetes Mellitus [THEMIS]: NCT01991795).

Novel Tissue Factor Inhibition for Thromboprophylaxis in COVID-19: Primary Results of the ASPEN-COVID-19 Trial

BACKGROUND

Thrombo-inflammation is central to COVID-19-associated coagulopathy. TF (tissue factor), a driver disordered coagulation and inflammation in viral infections, may be a therapeutic target in COVID-19. The safety and efficacy of the novel TF inhibitor rNAPc2 (recombinant nematode anticoagulation protein c2) in COVID-19 are unknown.

METHODS

ASPEN-COVID-19 was an international, randomized, open-label, active comparator clinical trial with blinded end point adjudication. Hospitalized patients with COVID-19 and elevated D-dimer levels were randomized 1:1:2 to lower or higher dose rNAPc2 on days 1, 3, and 5 followed by heparin on day 8 or to heparin per local standard of care. In comparisons of the pooled rNAPc2 versus heparin groups, the primary safety end point was major or nonmajor clinically relevant International Society of Thrombosis and Haemostasis bleeding through day 8. The primary efficacy end point was proportional change in D-dimer concentration from baseline to day 8, or discharge if before day 8. Patients were followed for 30 days.

RESULTS

Among 160 randomized patients, median age was 54 years, 43.1% were female, and 38.8% had severe baseline COVID-19. There were no significant differences between rNAPc2 and heparin in bleeding or other safety events. Overall, median change in D-dimer was -16.8% (interquartile range, -45.7 to 36.8; P=0.41) with rNAPc2 treatment and -11.2% (-36.0 to 34.4; P=0.91) with heparin (P_intergroup=0.47). In prespecified analyses, in severely ill patients, D-dimer levels tended to increase more within the heparin (median, 29.0% [-14.9 to 145.2]; P=0.02) than the rNAPc2 group (median, 25.9% [-49.1 to 136.4]; P=0.14; P_intergroup=0.96); in mildly ill patients, D-dimer levels were reduced within each group with a numerically greater reduction with rNAPc2 versus heparin (rNAPc2 median, -32.7% [-44.7 to 4.3]; P=0.007 and heparin median, -16.8% [-36.0 to 0.5]; P=0.008, P_intergroup=0.34).

CONCLUSIONS

rNAPc2 treatment in hospitalized patients with COVID-19 was well tolerated without excess bleeding or serious adverse events but did not significantly reduce D-dimer more than heparin at day 8.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT04655586.

Rivaroxaban in patients with symptomatic peripheral artery disease after lower extremity bypass surgery with venous and prosthetic conduits

BACKGROUND

Patients with peripheral artery disease (PAD) requiring lower extremity revascularization (LER) have a high risk of adverse limb and cardiovascular events. The results from the VOYAGER PAD (efficacy and safety of rivaroxaban in reducing the risk of major thrombotic vascular events in subjects with symptomatic peripheral artery disease undergoing peripheral revascularization procedures of the lower extremities) trial have demonstrated that rivaroxaban significantly reduced this risk with an overall favorable net benefit for patients undergoing surgical revascularization. However, the efficacy and safety for those treated by surgical bypass, including stratification by bypass conduit (venous or prosthetic), has not yet been described.

METHODS

In the VOYAGER PAD trial, patients who had undergone surgical and endovascular infrainguinal LER to treat PAD were randomized to rivaroxaban 2.5 mg twice daily or placebo on top of background antiplatelet therapy (aspirin 100 mg to be used in all and clopidogrel in some at the treating physician's discretion) and followed up for a median of 28 months. The primary end point was a composite of acute limb ischemia, major amputation of vascular etiology, myocardial infarction, ischemic stroke, and cardiovascular death. The principal safety outcome was major bleeding using the TIMI (thrombolysis in myocardial infarction) scale. The index procedure details, including conduit type (venous vs prosthetic), were collected at baseline.

RESULTS

Among 6564 randomized patients, 2185 (33%) had undergone surgical LER. Of these 2185 patients, surgical bypass had been performed for 1448 (66%), using a prosthetic conduit for 773 patients (53%) and venous conduit for 646 patients (45%). Adjusting for the baseline differences and anatomic factors, the risk of unplanned limb revascularization in the placebo arm was 2.5-fold higher for those receiving a prosthetic conduit vs a venous conduit (adjusted hazard ratio [HR], 2.53; 95% confidence interval [CI], 1.65-3.90; P < .001), and the risk of acute limb ischemia was three times greater (adjusted HR, 3.07; 95% CI, 1.84-5.11; P < .001). The use of rivaroxaban reduced the primary outcome for the patients treated with bypass surgery (HR, 0.78; 95% CI, 0.62-0.98), with consistent benefits for those receiving venous (HR, 0.66; 95% CI, 0.49-0.96) and prosthetic (HR, 0.87; 95% CI, 0.66-1.15) conduits (P_interaction = .254). In the overall trial, major bleeding using the TIMI scale was increased with rivaroxaban. However, the numbers for those treated with bypass surgery were low (five with rivaroxaban vs nine with placebo; HR, 0.55; 95% CI, 0.18-1.65) and not powered to show statistical significance.

CONCLUSIONS

Surgical bypass with a prosthetic conduit was associated with significantly higher rates of major adverse limb events relative to venous conduits even after adjustment for patient and anatomic characteristics. Adding rivaroxaban 2.5 mg twice daily to aspirin or dual antiplatelet therapy significantly reduced this risk, with an increase in the bleeding risk, but had a favorable benefit risk for patients treated with bypass surgery, regardless of conduit type. Rivaroxaban should be considered after lower extremity bypass for symptomatic PAD to reduce ischemic complications of the heart, limb, and brain.

Rivaroxaban and Risk of Venous Thromboembolism in Patients With Symptomatic Peripheral Artery Disease After Lower Extremity Revascularization

IMPORTANCE

Prior studies have observed an association between the burden of atherosclerotic vascular disease and the risk of venous thromboembolism (VTE). The association is not well described in peripheral artery disease (PAD) after lower extremity revascularization (LER).

OBJECTIVE

To describe the risk of, factors associated with, and outcomes after VTE, as well as the association of low-dose rivaroxaban plus antiplatelet therapy with VTE after LER.

DESIGN, SETTING, AND PARTICIPANTS

This global, multicenter cohort study used data from the Vascular Outcomes Study of ASA (acetylsalicylic acid) Along With Rivaroxaban in Endovascular or Surgical Limb Revascularization for PAD (VOYAGER PAD) randomized clinical trial, which enrolled patients from 2015 to 2018 with median follow-up of 28 months. Participants included patients with PAD undergoing LER. Patients with an indication for therapeutic anticoagulation were excluded. Data were analyzed from September 2020 to September 2021.

EXPOSURE

Randomization to rivaroxaban 2.5 mg twice daily or placebo on a background of aspirin 100 mg daily; short-term clopidogrel was used at the discretion of the treating physician.

MAIN OUTCOMES AND MEASURES

Symptomatic VTE was a prespecified secondary outcome and prospectively collected.

RESULTS

Among 6564 patients (median [IQR] age, 67 [61-73] years; 4860 [74.0%] men), 66 patients had at least 1 VTE. The 3-year rate of VTE in patients receiving placebo was 1.7%, and the pattern of risk was linear (year 1: 0.5%; year 2: 1.1%). After multivariable modeling, weight (hazard ratio [HR], 3.04; 95% CI, 1.09-8.43), hypertension (HR, 2.11; 95% CI, 0.91-4.89), prior amputation (HR, 2.07; 95% CI, 0.95-4.53), and older age (HR, 1.81; 95% CI, 1.06-3.11) were associated with increased risk of VTE. VTE was associated with risk of subsequent mortality (HR, 7.22; 95% CI, 4.66-11.19). Compared with aspirin alone, rivaroxaban plus aspirin was associated with lower VTE risk (HR, 0.61; 95% CI, 0.37-0.998; P = .047), with benefit apparent early and sustained over time. This association was not modified by use of clopidogrel at randomization (without clopidogrel: HR, 0.55; 95% CI, 0.29-1.07; with clopidogrel: HR, 0.69; 95% CI, 0.32-1.48; P for interaction = .67).

CONCLUSIONS AND RELEVANCE

In this cohort study, there was continuous risk for VTE after LER in patients with PAD, with greater risk in patients who were older and had obesity and those with more severe PAD, as reflected by prior amputation. Low-dose rivaroxaban plus aspirin was associated with lower VTE risk compared with aspirin alone, with benefits apparent early and continued over time. The spectrum of venous and arterial thrombotic events and overall benefits of more potent antithrombotic strategies for prevention should be considered after LER for PAD.

Prevention of arterial and venous thrombotic events in symptomatic peripheral arterial disease patients after lower extremity revascularization in the VOYAGER PAD trial: Dual anticoagulant/antiplatelet regimen vs antiplatelet therapy alone

BACKGROUND

Vascular disease burden after lower extremity revascularization (LER) comprises more than the first event, more vascular beds than the local arteries, and more than one clinical event type.

OBJECTIVES

Assess total arterial and venous thrombotic burden after LER for symptomatic peripheral artery disease (PAD) and effect of low-dose anticoagulation added to low-dose antiplatelet therapy.

PATIENTS/METHODS

VOYAGER PAD randomized 6564 symptomatic PAD patients undergoing LER to rivaroxaban 2.5 mg twice-daily or placebo on aspirin background. Marginal proportional-hazards models used to generate treatment hazard ratios and associated 95% CIs for first and total events; non-thrombotic deaths treated as competing terminal events. Incidence rates calculated as number of events per 100 patient-years follow-up.

RESULTS

Over 2.5 years (median), first and total thrombotic event rates: 7.1 and 10.3 events/100 patient-years, respectively, in placebo group. Two-thirds (925/1372) of total thrombotic events (arterial 95%, venous 5%) were nonfatal first events. Nearly one-third of patients with first event had a second arterial or venous thrombotic event. Rivaroxaban plus aspirin reduced first and total arterial and venous thrombotic events to 5.4 and 7.9 events/100 patient-years, respectively, a reduction in total thrombotic events over aspirin of 23% (HR: 0.77, 95%CI: 0.67-0.89, p = .0005), preventing 6.1 total arterial and venous thrombotic events at 3 years.

CONCLUSIONS

Assessing total arterial and venous thrombotic events, not just first events, provides more complete information about disease burden and absolute on-treatment impact. Following LER, judicious modulation of more than one coagulation pathway can provide broader benefit than intensifying inhibition of one hemostatic system component.

Rationale and design of a study to assess the safety and efficacy of rNAPc2 in COVID-19: the Phase 2b ASPEN-COVID-19 trial

Background

The interaction between thrombosis and inflammation appears central to COVID-19-associated coagulopathy and likely contributes to poor outcomes. Tissue factor is a driver of disordered coagulation and inflammatory signaling in viral infections and is important for viral replication; therefore, tissue factor may be an important therapeutic target in COVID-19.

Study Design

ASPEN-COVID-19 (NCT04655586) is a randomized, prospective open-label blinded endpoint (PROBE), active comparator Phase 2b trial to evaluate the safety and efficacy of recombinant Nematode Anticoagulant Protein c2 (rNAPc2), a potent tissue factor inhibitor, in patients hospitalized with COVID-19 with elevated D-dimer levels. This report describes the design of the Phase 2b dose ranging and proof of concept study. Participants are randomly assigned, in a 1:1:2 ratio, to lower or higher dose rNAPc2 by subcutaneous injection on days 1, 3, and 5 or to heparin according to local standard of care; randomization is stratified by baseline D-dimer level (at 2X upper limit of normal). The primary efficacy endpoint for Phase 2b is proportional change in D-dimer concentration from baseline to Day 8 or day of discharge, whichever is earlier. The primary safety endpoint is major or non-major clinically relevant bleeding through Day 8. Phase 2b enrollment began in December 2020 and is projected to complete ∼160 participants by Q4 2021.

Conclusions

ASPEN-COVID-19 will provide important data on a novel therapeutic approach that may improve outcomes in hospitalized COVID-19 patients beyond available anticoagulants by targeting tissue factor, with potential effects on not only thrombosis but also inflammation and viral propagation.

Safety and Effectiveness of Paclitaxel Drug-Coated Devices in Peripheral Artery Revascularization: Insights From VOYAGER PAD

BACKGROUND

Paclitaxel drug-coated devices (DCDs) were developed to improve lower extremity revascularization (LER) patency in peripheral artery disease (PAD) but have been associated with long-term mortality.

OBJECTIVES

This study assessed DCD safety and effectiveness in LER for PAD.

METHODS

VOYAGER PAD (Vascular Outcomes Study of ASA [acetylsalicylic acid] Along with Rivaroxaban in Endovascular or Surgical Limb Revascularization for PAD) randomized patients with PAD who underwent LER to rivaroxaban or placebo. The primary VOYAGER PAD study efficacy and safety outcomes were composite cardiovascular and limb events and Thrombolysis In Myocardial Infarction major bleeding. For prespecified DCD analyses, primary safety and effectiveness outcomes were mortality and unplanned index limb revascularization (UILR). Major adverse limb events (MALE) were a secondary outcome. Inverse probability treatment weighting was used to account for each subject's propensity for DCD treatment. Effects of rivaroxaban were assessed with Cox proportional hazards models.

RESULTS

Among 4,316 patients who underwent LER, 3,478 (80.6%) were treated for claudication, and 1,342 (31.1%) received DCDs. Median follow-up was 31 months, vital status was ascertained in 99.6% of patients, and there were 394 deaths. After weighting, DCDs were not associated with mortality (HR: 0.95; 95% CI: 0.83-1.09) or MALE (HR: 1.08; 95% CI: 0.90-1.30) but were associated with reduced UILR (3-year Kaplan-Meier: 21.5% vs 24.6%; HR: 0.84; 95% CI: 0.76-0.92). Irrespective of DCD use, consistent benefit of rivaroxaban for composite cardiovascular and limb events (P_interaction = 0.88) and safety of rivaroxaban with respect to bleeding (P_interaction = 0.57) were observed.

CONCLUSIONS

In >4,000 patients with PAD who underwent LER, DCDs were not associated with mortality or MALE but were associated with persistent reduction in UILR. These findings provide insight into the safety and effectiveness of DCDs in PAD. (Vascular Outcomes Study of ASA [acetylsalicylic acid] Along with Rivaroxaban in Endovascular or Surgical Limb Revascularization for PAD [VOYAGER PAD]; NCT02504216).

Low-dose rivaroxaban plus aspirin in older patients with peripheral artery disease undergoing acute limb revascularization: insights from the VOYAGER PAD trial

AIMS

In this secondary analysis of the VOYAGER trial, rivaroxaban 2.5 mg twice/day plus aspirin 100 mg/day was assessed in older adults. Advanced age is associated with elevated bleeding risk and unfavourable net benefit for dual antiplatelet therapy in chronic coronary artery disease. The risk-benefit of low-dose rivaroxaban in patients ≥75 years with peripheral artery disease (PAD) after lower extremity revascularization (LER) has not been described.

METHODS AND RESULTS

The primary endpoint was a composite of acute limb ischaemia, major amputation, myocardial infarction, ischaemic stroke, or cardiovascular death. The principal safety outcome was thrombolysis in myocardial infarction (TIMI) major bleeding analysed by the pre-specified age cut-off of 75 years. Of 6564 patients randomized, 1330 (20%) were >75 years. Absolute 3-year Kaplan-Meier cumulative incidence rates for primary efficacy (23.4% vs. 19.0%) and safety (3.5% vs. 1.5%) endpoints were higher in elderly vs. non-elderly patients. Efficacy of rivaroxaban (P-interaction 0.83) and safety (P-interaction 0.38) was consistent irrespective of age. The combination of intracranial and fatal bleeding was not increased in patients >75 years (2 rivaroxaban vs. 8 placebo). Overall, benefits (absolute risk reduction 3.8%, number needed to treat 26 for the primary endpoint) exceeded risks (absolute risk increase 0.81%, number needed to harm 123 for TIMI major bleeding).

CONCLUSION

Patients ≥75 years with PAD are at both heightened ischaemic and bleeding risk after LER. No excess harm with respect to major, intracranial or fatal bleeding was seen in older patients yet numerically greater absolute benefits were observed. This suggests that low-dose rivaroxaban combined with aspirin should be considered in PAD after LER regardless of age.

Reduction in Acute Limb Ischemia with Rivaroxaban versus Placebo in Peripheral Artery Disease after Lower Extremity Revascularization: Insights from VOYAGER PAD

Background: Patients with peripheral artery disease (PAD) are at heightened risk of acute limb ischemia (ALI), a thrombotic event associated with amputation, disability, and mortality. Prior lower extremity revascularization (LER) is associated with increased ALI risk in chronic PAD. However, the pattern of risk, clinical correlates, and outcomes after ALI early after LER are not well-studied, and effective therapies to reduce ALI post-LER are lacking. Methods: VOYAGER PAD (NCT02504216) randomized patients with PAD undergoing LER to rivaroxaban 2.5 mg twice daily or placebo on a background of low-dose aspirin. The primary outcome was a composite of ALI, major amputation of vascular cause, myocardial infarction, ischemic stroke, or cardiovascular death. ALI was prospectively ascertained and adjudicated by a blinded committee. The cumulative incidence of ALI was calculated using Kaplan Meier estimates, and Cox proportional-hazards models were used to generate hazard ratios and associated confidence intervals. Analyses were performed as intention-to-treat. Results: Among 6,564 patients followed for a median of 2.3 years, 382 (5.8%) had a total of 508 ALI events. In placebo patients, the 3-year cumulative incidence of ALI was 7.8%. After multivariable modeling, prior LER, baseline ABI <0.50, surgical LER, and longer target lesion length were associated with increased risk of ALI. Incident ALI was associated with subsequent all-cause mortality (HR 2.59, 95% CI 1.98-3.39) and major amputation (HR 24.87, 95% CI 18.68-33.12). Rivaroxaban reduced ALI relative to placebo by 33% (absolute risk reduction 2.6% at 3 years, HR 0.67, 95% CI 0.55-0.82, P=0.0001), with benefit starting early (HR 0.45, 95% CI 0.24-0.85, P=0.0068 at 30 days). Benefit was present for severe ALI (associated with death, amputation, or prolonged hospitalization and ICU stay, HR 0.58, 95% CI 0.40-0.83, P=0.003) and regardless of LER type (surgical vs endovascular revascularization, p-interaction=0.42) or clopidogrel use (p-interaction=0.59). Conclusions: After LER for symptomatic PAD, ALI is frequent, particularly early after LER, and is associated with poor prognosis. Low-dose rivaroxaban plus aspirin reduces ALI after LER, including ALI events associated with the most severe outcomes. The benefit of rivaroxaban for ALI appears early, continues over time, and is consistent regardless of revascularization approach or clopidogrel use.

Effect of Rivaroxaban and Aspirin in Patients with Peripheral Artery Disease Undergoing Surgical Revascularization: Insights from the VOYAGER PAD Trial

Background: Patients with peripheral artery disease (PAD) requiring lower extremity revascularization (LER) are at high risk of adverse limb and cardiovascular events. VOYAGER PAD demonstrated that rivaroxaban significantly reduced this risk. The efficacy and safety of rivaroxaban has not been described in patients who underwent surgical LER. Methods: The VOYAGER PAD trial randomized patients with PAD after surgical and endovascular LER to rivaroxaban 2.5mg twice daily plus aspirin or matching placebo plus aspirin and followed for a median of 28 months. The primary endpoint was a composite of acute limb ischemia, major vascular amputation, myocardial infarction, ischemic stroke, or cardiovascular death. The principal safety outcome was Thrombolysis in Myocardial Infarction (TIMI) major bleeding. International Society on Thrombosis and Haemostasis (ISTH) bleeding was a secondary safety outcome. All efficacy and safety outcomes were adjudicated by a blinded independent committee. Results: Of the 6564 randomized, 2185 (33%) underwent surgical LER and 4379 (67%) endovascular. Compared to placebo, rivaroxaban reduced the primary endpoint consistently regardless of LER method (p-interaction 0.43). Following surgical LER, the primary efficacy outcome occurred in 199 (18.4%) patients in the rivaroxaban group and 242 (22.0%) patients in the placebo group with a cumulative incidence at 3 years of 19.7% and 23.9%, respectively (HR 0.81, 95% CI 0.67 - 0.98; p=0.026). In the overall trial, TIMI major bleeding and ISTH major bleeding were increased with rivaroxaban. There was no heterogeneity for TIMI major bleeding (p-interaction 0.17) or ISTH major bleeding (p-interaction 0.73) based on LER approach. Following surgical LER, the principal safety outcome occurred in 11 (1.0%) patients in the rivaroxaban group and 13 (1.2%) patients in the placebo group; 3-year cumulative incidence 1.3% and 1.4% respectively (HR 0.88, 95% CI 0.39-1.95; p=0.75) Among surgical patients, the composite of fatal bleeding or intracranial hemorrhage (p=0.95) and postprocedural bleeding requiring intervention (p=0.93) were not significantly increased. Conclusions: The efficacy of rivaroxaban is associated with a benefit in surgical LER patients. While bleeding was increased with rivaroxaban plus aspirin, the incidence was low, with no significant increase in fatal bleeding, intracranial hemorrhage or postprocedural bleeds requiring intervention. Clinical Trial Registration: URL: https://clinicaltrials.gov Unique Identifier: NCT02504216.

Total Ischemic Event Reduction With Rivaroxaban After Peripheral Arterial Revascularization in the VOYAGER PAD Trial

BACKGROUND

Patients with peripheral artery disease (PAD) undergoing lower extremity revascularization (LER) are at high risk of major adverse limb and cardiovascular events. The VOYAGER PAD (Efficacy and Safety of Rivaroxaban in Reducing the Risk of Major Thrombotic Vascular Events in Subjects With Symptomatic Peripheral Artery Disease Undergoing Peripheral Revascularization Procedures of the Lower Extremities) trial demonstrated that rivaroxaban 2.5 mg twice daily reduced first events by 15%. The benefit of rivaroxaban on total (first and subsequent) events in this population is unknown.

OBJECTIVES

This study sought to evaluate the total burden of vascular events in patients with PAD after LER and the efficacy of low-dose rivaroxaban on total events.

METHODS

VOYAGER PAD randomized patients with PAD undergoing LER to rivaroxaban 2.5 mg twice daily plus aspirin or aspirin alone. The primary endpoint was time to first event of acute limb ischemia, major amputation of a vascular cause, myocardial infarction, ischemic stroke, or cardiovascular death. The current analysis considered all events (first and subsequent) for components of the primary endpoint as well as additional vascular events including peripheral revascularizations and venous thromboembolism. HRs were estimated by marginal proportional hazards models.

RESULTS

Among 6,564 randomized events, there were 4,714 total first and subsequent vascular events including 1,614 primary endpoint events and 3,100 other vascular events. Rivaroxaban reduced total primary endpoint events (HR: 0.86; 95% CI: 0.75-0.98; P = 0.02) and total vascular events (HR: 0.86; 95% CI: 0.79-0.95; P = 0.003). An estimated 4.4 primary and 12.5 vascular events per 100 participants were avoided with rivaroxaban over 3 years.

CONCLUSIONS

Patients with symptomatic PAD who are undergoing LER have a high total event burden that is significantly reduced with rivaroxaban. Total event reduction may be a useful metric to quantify the efficacy of rivaroxaban in this setting. (Efficacy and Safety of Rivaroxaban in Reducing the Risk of Major Thrombotic Vascular Events in Subjects With Symptomatic Peripheral Artery Disease Undergoing Peripheral Revascularization Procedures of the Lower Extremities [VOYAGER PAD]; NCT02504216).

Rationale and design for the study of rivaroxaban to reduce thrombotic events, hospitalization and death in outpatients with COVID-19: The PREVENT-HD study

BACKGROUND

COVID-19 is associated with both venous and arterial thrombotic complications. While prophylactic anticoagulation is now widely recommended for hospitalized patients with COVID-19, the effectiveness and safety of thromboprophylaxis in outpatients with COVID-19 has not been established.

STUDY DESIGN

PREVENT-HD is a double-blind, placebo-controlled, pragmatic, event-driven phase 3 trial to evaluate the efficacy and safety of rivaroxaban in symptomatic outpatients with laboratory-confirmed COVID-19 at risk for thrombotic events, hospitalization, and death. Several challenges posed by the pandemic have necessitated innovative approaches to clinical trial design, start-up, and conduct. Participants are randomized in a 1:1 ratio, stratified by time from COVID-19 confirmation, to either rivaroxaban 10 mg once daily or placebo for 35 days. The primary efficacy end point is a composite of symptomatic venous thromboembolism, myocardial infarction, ischemic stroke, acute limb ischemia, non-central nervous system systemic embolization, all-cause hospitalization, and all-cause mortality. The primary safety end point is fatal and critical site bleeding according to the International Society on Thrombosis and Haemostasis definition. Enrollment began in August 2020 and is expected to enroll approximately 4,000 participants to yield the required number of end point events.

CONCLUSIONS

PREVENT-HD is a pragmatic trial evaluating the efficacy and safety of the direct oral anticoagulant rivaroxaban in the outpatient setting to reduce major venous and arterial thrombotic events, hospitalization, and mortality associated with COVID-19.

Exercise Training and Revascularization in the Management of Symptomatic Peripheral Artery Disease

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In the management of symptomatic peripheral artery disease, aerobic exercise therapy and lower extremity revascularization are the mainstays of therapy.

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In this structured review, the most effective therapies, with 6 to 18 months of follow-up, indicated that exercise therapy and lower extremity revascularization each independently improve peak walking performance.

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The combination of therapies was superior to either therapy alone and may decrease the need for subsequent revascularization.

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Further research is needed to evaluate the long-term durability of these interventions, their impacts on subsequent invasive procedures, and predictors of response.

Exercise therapy and lower extremity revascularization both improve walking performance in symptomatic patients with peripheral artery disease. The combination of therapies provides greater benefit than either alone and may reduce the need for subsequent revascularization procedures, but further trials with longer follow-up are needed for the outcome of subsequent revascularization.

Should Participants in Clinical Trials Be Able to Withdraw from Passive Follow-Up?

A research participant's right to withdraw from all research procedures is widely accepted, but there can be justifiable limits to a participant's exercise of autonomy to withdraw from some procedures. Clinical outcomes trials depend on complete subject follow-up for accurate assessment of the safety and efficacy of investigational therapies. Subjects' refusal to complete follow-up, even through passive medical record review, can cause failure to detect safety signals, inaccurate estimation of efficacy, or lack of acceptance of trial results, which alters the study's benefit-risk ratio. Allowing participant refusal of follow-up data collection therefore creates tension between respect for persons and beneficence. With minimal risk study procedures that can help preserve trial benefit, such as passive data collection, we argue that the importance of upholding the principle of beneficence outweighs individual autonomy concerns. Furthermore, a consent process that prospectively informs participants of mandatory passive follow-up is ethically justified and optimizes the balance between autonomy and beneficence.

Rivaroxaban and Aspirin in Peripheral Artery Disease Lower Extremity Revascularization

Background:

The VOYAGER PAD trial (Vascular Outcomes Study of ASA Along With Rivaroxaban in Endovascular or Surgical Limb Revascularization for Peripheral Artery Disease) demonstrated superiority of rivaroxaban plus aspirin versus aspirin to reduce major cardiac and ischemic limb events after lower extremity revascularization. Clopidogrel is commonly used as a short-term adjunct to aspirin after endovascular revascularization. Whether clopidogrel modifies the efficacy and safety of rivaroxaban has not been described.

Methods:

VOYAGER PAD was a phase 3, international, double-blind, placebo-controlled trial in patients with symptomatic PAD undergoing lower extremity revascularization randomized to rivaroxaban 2.5 mg twice daily plus 100 mg aspirin daily or rivaroxaban placebo plus aspirin. The primary efficacy outcome was a composite of acute limb ischemia, major amputation of a vascular cause, myocardial infarction, ischemic stroke, or cardiovascular death. The principal safety end point was TIMI (Thrombolysis in Myocardial Infarction) major bleeding, with International Society on Thrombosis and Haemostasis major bleeding a secondary safety outcome. Clopidogrel use was allowed at the discretion of the investigator for up to 6 months after the qualifying revascularization.

Results:

Of the randomized patients, 3313 (50.6%) received clopidogrel for a median duration of 29.0 days. Over 3 years, the hazard ratio for the primary outcome of rivaroxaban versus placebo was 0.85 (95% CI, 0.71–1.01) with clopidogrel and 0.86 (95% CI, 0.73–1.01) without clopidogrel without statistical heterogeneity ( P for interaction=0.92). Rivaroxaban resulted in an early apparent reduction in acute limb ischemia within 30 days (hazard ratio, 0.45 [95% CI, 0.14–1.46] with clopidogrel; hazard ratio, 0.48 [95% CI, 0.22–1.01] without clopidogrel; P for interaction=0.93). Compared with aspirin, rivaroxaban increased TIMI major bleeding similarly regardless of clopidogrel use ( P for interaction=0.71). With clopidogrel use >30 days, rivaroxaban was associated with more International Society on Thrombosis and Haemostasis major bleeding within 365 days (hazard ratio, 3.20 [95% CI, 1.44–7.13]) compared with shorter durations of clopidogrel ( P for trend=0.06).

Conclusions:

In the VOYAGER PAD trial, rivaroxaban plus aspirin reduced the risk of adverse cardiovascular and limb events with an early benefit for acute limb ischemia regardless of clopidogrel use. The safety of rivaroxaban was consistent regardless of clopidogrel use but with a trend for more International Society on Thrombosis and Haemostasis major bleeding with clopidogrel use >30 days than with a shorter duration. These data support the addition of rivaroxaban to aspirin after lower extremity revascularization regardless of concomitant clopidogrel, with a short course (≤30 days) associated with less bleeding.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02504216.

Rivaroxaban in Peripheral Artery Disease after Revascularization

BACKGROUND

Patients with peripheral artery disease who have undergone lower-extremity revascularization are at high risk for major adverse limb and cardiovascular events. The efficacy and safety of rivaroxaban in this context are uncertain.

METHODS

In a double-blind trial, patients with peripheral artery disease who had undergone revascularization were randomly assigned to receive rivaroxaban (2.5 mg twice daily) plus aspirin or placebo plus aspirin. The primary efficacy outcome was a composite of acute limb ischemia, major amputation for vascular causes, myocardial infarction, ischemic stroke, or death from cardiovascular causes. The principal safety outcome was major bleeding, defined according to the Thrombolysis in Myocardial Infarction (TIMI) classification; major bleeding as defined by the International Society on Thrombosis and Haemostasis (ISTH) was a secondary safety outcome.

RESULTS

A total of 6564 patients underwent randomization; 3286 were assigned to the rivaroxaban group, and 3278 were assigned to the placebo group. The primary efficacy outcome occurred in 508 patients in the rivaroxaban group and in 584 in the placebo group; the Kaplan-Meier estimates of the incidence at 3 years were 17.3% and 19.9%, respectively (hazard ratio, 0.85, 95% confidence interval [CI], 0.76 to 0.96; P = 0.009). TIMI major bleeding occurred in 62 patients in the rivaroxaban group and in 44 patients in the placebo group (2.65% and 1.87%; hazard ratio, 1.43; 95% CI, 0.97 to 2.10; P = 0.07). ISTH major bleeding occurred in 140 patients in the rivaroxaban group, as compared with 100 patients in the placebo group (5.94% and 4.06%; hazard ratio, 1.42; 95% CI, 1.10 to 1.84; P = 0.007).

CONCLUSIONS

In patients with peripheral artery disease who had undergone lower-extremity revascularization, rivaroxaban at a dose of 2.5 mg twice daily plus aspirin was associated with a significantly lower incidence of the composite outcome of acute limb ischemia, major amputation for vascular causes, myocardial infarction, ischemic stroke, or death from cardiovascular causes than aspirin alone. The incidence of TIMI major bleeding did not differ significantly between the groups. The incidence of ISTH major bleeding was significantly higher with rivaroxaban and aspirin than with aspirin alone. (Funded by Bayer and Janssen Pharmaceuticals; VOYAGER PAD ClinicalTrials.gov number, NCT02504216.).

A randomized trial of heart failure disease management in skilled nursing facilities (SNF Connect): Lessons learned

BACKGROUND/AIMS

Conducting clinical trials in skilled nursing facilities is particularly challenging. This manuscript describes facility and patient recruitment challenges and solutions for clinical research in skilled nursing facilities.

METHODS

Lessons learned from the SNF Connect Trial, a randomized trial of a heart failure disease management versus usual care for patients with heart failure receiving post-acute care in skilled nursing facilities, are discussed. Description of the trial design and barriers to facility and patient recruitment along with regulatory issues are presented.

RESULTS

The recruitment of Denver-metro skilled nursing facilities was facilitated by key stakeholders of the skilled nursing facilities community. However, there were still a number of barriers to facility recruitment including leadership turnover, varying policies regarding research, fear of litigation and of an increased workload. Engagement of facilities was facilitated by their strong interest in reducing hospital readmissions, marketing potential to hospitals, and heart failure management education for their staff. Recruitment of patients proved difficult and there were few facilitators. Identified patient recruitment challenges included patients being unaware of their heart failure diagnosis, patients overwhelmed with their illness and care, and frequently there was no available proxy for cognitively impaired patients. Flexibility in changing the recruitment approach and targeting skilled nursing facilities with higher rates of admissions helped to overcome some barriers.

CONCLUSION

Recruitment of skilled nursing facilities and patients in skilled nursing facilities for clinical trials is challenging. Strategies to attract both facilities and patients are warranted. These include aligning study goals with facility incentives and flexible recruitment protocols to work with patients in "transition crisis."

Ethical conduct of palliative care research: enhancing communication between investigators and institutional review boards

Palliative care has faced moral and ethical challenges when conducting research involving human subjects. There are currently no resources to guide institutional review boards (IRBs) in applying standard ethical principles and terms-in a specific way-to palliative care research. Using as a case study a recently completed multisite palliative care clinical trial, this article provides guidance and recommendations for both IRBs and palliative care investigators to facilitate communication and attain the goal of conducting ethical palliative care research and protecting study participants while advancing the science. Beyond identifying current challenges faced by palliative care researchers and IRBs reviewing palliative care research, this article suggests steps that the palliative care research community can take to establish a scientifically sound, stable, productive, and well-functioning relationship between palliative care investigators and the ethical bodies that oversee their work.

Fatty acids increase glucose uptake and metabolism in C2C12 myoblasts stably transfected with human lipoprotein lipase

Cellular effects of FFA might differ from those of lipoprotein triglyceride (TG)-derived fatty acids (TGFA). The aim of the current study was to examine the relationship between lipoprotein lipase (LPL) expression, TGFA, or FFA availability and glucose metabolism in the absence of insulin in C2C12 myoblasts. Control myoblasts or myoblasts stably transfected with human lipoprotein lipase (C2/LPL; 15-fold greater LPL activity) were incubated for 12 h in fetal bovine serum-free medium in the absence or presence of Intralipid-20. Intracellular retention of labeled medium glucose was assessed in a subset of experiments. In the presence of Intralipid, medium glucose disappearance was increased in C2/LPL cells but not in control cells. In both cell types, glucose label retention in cellular TG was increased in the presence of Intralipid; incubation with albumin-bound oleate produced similar results. In the presence of Intralipid, the LPL hydrolytic inhibitor tetrahydrolipstatin blocked excess glucose retention in cellular TG but did not significantly decrease glucose disappearance in C2/LPL cells. Changes in glucose transport or hexokinase II did not explain the altered glucose disappearance in C2/LPL cells. Our results suggest that LPL overexpression in these cells leads to chronic metabolic adaptations that alter glucose uptake and retention.

Lack of suppression of circulating free fatty acids and hypercholesterolemia during weight loss on a high-fat, low-carbohydrate diet

BACKGROUND

Little is known about the comparative effect of weight-loss diets on metabolic profiles during dieting.

OBJECTIVE

The purpose of this study was to compare the effect of a low-carbohydrate diet (< or =20 g/d) with a high-carbohydrate diet (55% of total energy intake) on fasting and hourly metabolic variables during active weight loss.

DESIGN

Healthy, obese adults (n = 32; 22 women, 10 men) were randomly assigned to receive either a carbohydrate-restricted diet [High Fat; mean +/- SD body mass index (BMI; in kg/m(2)): 35.8 +/- 2.9] or a calorie-restricted, low-fat diet (High Carb; BMI: 36.7 +/- 4.6) for 6 wk. A 24-h in-patient feeding study was performed at baseline and after 6 wk. Glucose, insulin, free fatty acids (FFAs), and triglycerides were measured hourly during meals, at regimented times. Remnant lipoprotein cholesterol was measured every 4 h.

RESULTS

Patients lost a similar amount of weight in both groups (P = 0.57). There was an absence of any diet treatment effect between groups on fasting triglycerides or on remnant lipoprotein cholesterol, which was the main outcome. Fasting insulin decreased (P = 0.03), and both fasting (P = 0.040) and 24-h FFAs (P < 0.0001) increased within the High Fat group. Twenty-four-hour insulin decreased (P < 0.05 for both groups). Fasting LDL cholesterol decreased in the High Carb group only (P = 0.003). In both groups, the differences in fasting and 24-h FFAs at 6 wk were significantly correlated with the change in LDL cholesterol (fasting FFA: r = 0.41, P = 0.02; 24-h FFA: r = 0.52, P = 0.002).

CONCLUSIONS

Weight loss was similar between diets, but only the high-fat diet increased LDL-cholesterol concentrations. This effect was related to the lack of suppression of both fasting and 24-h FFAs.

Plant sterols added to combination statin and colesevelam hydrochloride therapy failed to lower low-density lipoprotein cholesterol concentrations

BACKGROUND

The purpose of this study was to evaluate the effects on LDL-cholesterol (LDL-C) from addition of plant sterol treatment to patients with dyslipidemia already taking a statin and colesevelam hydrochloride (HCl). Current cholesterol treatment guidelines recommend use of plant stanols/sterols to help reach LDL-C goals in patients taking other lipid-lowering therapies. Previous data demonstrate LDL-C lowering by adding stanols/sterols to statins. However, data are conflicting regarding the benefit from combination stanols/sterols with bile acid sequestrants.

METHODS

Fifty-five subjects on a stable dose of statin completed a 10-week, double-blind, randomized study of colesevelam HCl 3.75 g/day alone for 4 weeks, then 6 weeks of additional 2 g/day plant sterol-fortified orange juice (S-OJ) or placebo orange juice (P-OJ). Serum total cholesterol (TC), LDL-C, HDL-cholesterol (HDL-C), triglycerides (TG), apolipoprotein B (ApoB), and high-sensitivity C-reactive protein (hs-CRP) were measured at baseline, 4 weeks, and 10 weeks.

RESULTS

Baseline LDL-C measurements (mean ± SD) were similar between S-OJ and P-OJ groups (122 ± 20 vs 126 ± 24 mg/dL, respectively). Four weeks of colesevelam HCl in combination with a statin significantly reduced TC, LDL-C, and ApoB (9.6%, P < 0.001; 21.9%, P < 0.001; and 8.5%, P = 0.001, respectively), and significantly increased HDL-C (6.2%, P = 0.002) and TG (18.8%, P = 0.002). However, compared to P-OJ, 10 weeks of S-OJ produced no effect on any outcome parameter beyond that of colesevelam HCl.

CONCLUSION

Plant S-OJ appears to be ineffective at further reducing LDL-C when added to statin and colesevelam HCl combination therapy in patients with dyslipidemia.

Time course of C-reactive protein reduction with simvastatin therapy in patients with type 2 diabetes mellitus

The aim of this study was to investigate the time course of C-reactive protein (CRP) reduction with simvastatin in patients with type 2 diabetes mellitus. Thirty-five subjects (mean +/- SEM body mass index 32.8 +/- 1 kg/m(2), mean +/- SEM glycated hemoglobin 7.3 +/- 0.2%) were studied using a randomized, crossover, double-blind design. Patients were treated with simvastatin 40 mg or placebo for 28 days, with a minimum 28-day intervening washout. On entry, all subjects had low-density lipoprotein cholesterol >100 mg/dl and/or non-high-density lipoprotein cholesterol >130 mg/dl. High-sensitivity CRP (hs-CRP) was measured on days 0, 1, 3, 7, 14, 21, and 28 of each phase; fasting lipids were measured weekly. The mean hs-CRP level was 4.2 +/- 0.6 mg/L at baseline (>3.0 mg/L represents high risk). After simvastatin administration, there was a significant reduction in levels of log(hs-CRP) (p = 0.001). This effect of simvastatin was seen by day 7 (p = 0.008), with maximal reduction seen at day 14 (p = 0.004; hs-CRP in original units 3.1 +/- 0.5 mg/L with simvastatin and 4.1 +/- 0.6 mg/L with placebo). As expected, the change in hs-CRP was not related to low-density lipoprotein cholesterol reduction. By day 28 with simvastatin, hs-CRP had returned to near baseline levels. In conclusion, in patients with type 2 diabetes mellitus, simvastatin reduced hs-CRP within 7 days. However, this potentially beneficial effect was lost within 28 days.

Treatment of hypertriglyceridemia

Hypertriglyceridemia is a disorder commonly encountered in clinical practice. Treatment of this condition aims to prevent the major complications of hypertriglyceridemia, which differ depending on whether triglyceride elevations are moderate or severe. This review discusses the pathophysiology and clinical consequences of hypertriglyceridemia and outlines treatment approaches based on the degree of triglyceride elevation. Special consideration is given to clinical trials using medications that primarily target triglycerides.

Severe hypertriglyceridemia with a history of treatment failure

Background A 53-year-old man with a history of hypertension and gout was referred to our clinic for severe hypertriglyceridemia, diagnosed 3 years previously. He was asymptomatic and had no history of abdominal pain, pancreatitis or diabetes, but consumed six cans of beer per night. Over the previous 2 years, he had been treated unsuccessfully with multiple medications; during this period his fasting triglycerides ranged from 5.41 mM to 55.04 mM (479 to 4,871 mg/dl). Investigations Physical examination including fundoscopy, medication review, and laboratory tests.Diagnosis Severe hypertriglyceridemia due to a genetic combined hyperlipidemia, exacerbated by persistent excessive alcohol intake and metabolic syndrome. Management Cessation of alcohol intake, initiation of a fat-restricted diet, and fibrate therapy, with close follow-up. Once serum triglycerides were controlled, attention was turned to lowering LDL-cholesterol concentration according to The National Cholesterol Education Program, Adult Treatment Panel III guidelines.

Increased expression of the SNARE accessory protein Munc18c in lipid-mediated insulin resistance

Fatty acids inhibit insulin-mediated glucose metabolism in skeletal muscle, an effect largely attributed to defects in insulin-mediated glucose transport. Insulin-resistant mice transgenic for the overexpression of lipoprotein lipase (LPL) in skeletal muscle were used to examine the molecular mechanism(s) in more detail. Using DNA gene chip array technology, and confirmation by RT-PCR and Western analysis, increases in the yeast Sec1p homolog Munc18c mRNA and protein were found in the gastrocnemius muscle of transgenic mice, but not other tissues. Munc18c has been previously demonstrated to impair insulin-mediated glucose transport in mammalian cells in vitro. Of interest, stably transfected C2C12 cells overexpressing LPL not only demonstrated increases in Munc18c mRNA and protein but also in transcription rates of the Munc18c gene. To confirm the relevance of fatty acid metabolism and insulin resistance to the expression of Munc18c in vivo, a 2-fold increase in Munc18c protein was demonstrated in mice fed a high-fat diet for 4 weeks. Together, these data are the first to implicate in vivo increases in Munc18c as a potential contributing mechanism to fatty acid-induced insulin resistance.

Short-term triglyceride lowering with fenofibrate improves vasodilator function in subjects with hypertriglyceridemia

OBJECTIVE

The objective of this study was to investigate the effects of lowering plasma triglycerides (TGs) on endothelial function and gain insight into the role played by free fatty acids (FFAs) in hypertriglyceridemia-associated vascular dysfunction.

METHODS AND RESULTS

Eleven hypertriglyceridemic subjects without coronary artery disease, diabetes, elevated low-density lipoprotein cholesterol, tobacco use, or hypertension were studied using a randomized, double-blinded, crossover design (fenofibrate and placebo, 14 days). After each regimen, forearm blood flow was assessed by plethysmography in response to arterial acetylcholine, nitroprusside, and verapamil infusion. Hourly plasma TGs, FFA, glucose, and insulin were measured during a 24-hour feeding cycle to characterize the metabolic environment. Changes in plasma FFA after intravenous heparin were used to estimate typical FFA accumulation in the luminal endothelial microenvironment. Fenofibrate lowered plasma TG (P<0.001), total cholesterol (P<0.01), and apolipoprotein B (P<0.01) without altering high-density lipoprotein or low-density lipoprotein cholesterol concentrations. Forearm blood flow in response to acetylcholine (P<0.0001), nitroprusside (P<0.001), and verapamil (P<0.0001) improved after fenofibrate. Fenofibrate lowered 24-hour (P<0.0001) and post-heparin (P<0.001) TG and tended to lower 24-hour (P=0.054) and post-heparin (P=0.028) FFA.

CONCLUSIONS

Vascular smooth muscle function significantly improves after lowering plasma TG without changes in confounding lipoproteins or insulin resistance. The data raise additional questions regarding the role of FFA in hypertriglyceridemia-associated vascular dysfunction.

Compositional differences of LDL particles in normal subjects with LDL subclass phenotype A and LDL subclass phenotype B

A predominance of small LDL particles (subclass phenotype B), as determined by gradient-gel electrophoresis is found among patients with myocardial infarction. Despite physical differences in phenotype A and B particles, differences in lipid composition of particles in these phenotypes have yet to be reported in an unselected population of males and females. The present study used lipid/apoB ratios to analyze the amount of lipid per LDL particle, isolated by density-gradient ultracentrifugation, in 70 healthy subjects. Relative to apoB, the LDL particles from phenotype B subjects were found to contain less free cholesterol (0.391 +/- 0.05 versus 0.465 +/- 0.05; mean +/- SD; P < .001), phospholipid (1.26 +/- 0.2 versus 1.43 +/- 0.2; P < .001), and cholesteryl ester (1.97 +/- 0.1 versus 2.11 +/- 0.2; P < .001) than particles from phenotype A subjects. The amount of triglyceride per LDL particle did not differ between the two phenotypes (0.410 +/- 0.1 versus 0.406 +/- 0.1; P = NS) despite higher plasma triglyceride levels in the phenotype B subjects. LDL size and buoyancy were positively correlated with particle free cholesterol, phospholipid, and cholesteryl ester but not with particle triglyceride. These data suggest that the physical properties of LDL from subjects with phenotype A and B reflect their lipid composition. The compositional differences between LDL particles of the two phenotypes may provide new insight into the increased risk of myocardial infarction in subjects with small, dense LDL.