Safety and Efficacy of Polymer-Free Biolimus A9–Coated Versus Bare-Metal Stents in Orally Anticoagulated Patients

Rationale and design of the optimal antithrombotic treatment for acute coronary syndrome patients with concomitant atrial fibrillation and implanted with new-generation drug-eluting stent: OPtimal management of anTIthroMbotic Agents (OPTIMA)-4 trial

BACKGROUND

About 5%-15% of acute coronary syndrome (ACS) patients undergoing stent implantation have concomitant atrial fibrillation and need both antiplatelet and anticoagulant therapies. The optimal antithrombotic regimen remains uncertain in this scenario.

HYPOTHESIS

A multicenter randomized controlled trial (OPtimal management of anTIthroMbotic Agents [OPTIMA]-4) is designed to test the hypothesis that, for ACS patients with concomitant nonvalvular atrial fibrillation (NVAF) and having low-to-moderate risk of bleeding, clopidogrel is comparable in efficacy but superior in safety compared to ticagrelor while being used in combination with dabigatran after new-generation drug-eluting stent (DES) implantation.

METHODS

ACS patients who have low-to-moderate risk of bleeding (e.g., HAS-BLED score ≤ 2) and require anticoagulation therapy (CHA₂ DS₂ -VASc score ≥ 2) will be recruited after implantation of new-generation DES. A total of 1472 eligible patients will be randomly assigned to receive a 12-month dual antithrombotic treatment of either clopidogrel 75 mg daily or ticagrelor 90 mg twice daily in combination with dabigatran 110 mg twice daily. Participants will be followed up for 12 months after randomization. The primary efficacy endpoint is a composite of cardiovascular death, myocardial infarction, unplanned revascularization, ischemic stroke, and systemic thromboembolism. The primary safety endpoint is set as major bleeding or clinically relevant nonmajor bleeding defined by the International Society of Thrombosis and Hemostasis. The enrollment and follow-up have been launched.

RESULTS

The first enrollment occurred on March 12, 2018. The recruitment is anticipated to be completed before December 31, 2024.

CONCLUSIONS

The OPTIMA-4 trial offers an opportunity to assess the optimal dual antithrombotic regimen in ACS patients with concomitant NVAF after the implantation of new-generation DES.

The Biolimus A9-coated BioFreedom™ stent: from clinical efficacy to real-world evidence

In this state-of-the-art review, we present the findings and a critical analysis of the Leaders Free trial program, evaluating outcomes of a new stent-generation based on polymer-free technology, in this case the BioFreedom^™ (Biosensors Europe, Switzerland), in patients at high bleeding risk (HBR). Polymer-free drug-coated stents were designed to obtain a device with the antirestenotic benefits of drug-eluting stents but without the polymer coating as potential trigger for delayed arterial wall healing and subsequent late ischemic adverse events, causing a prolonged dependence on dual antiplatelet therapy after stenting. This offers therefore the potential of a promising device-based strategy in a complex growing population of patients with combined HBR and high thrombosis risk, due to the possible reduction of antithrombotic duration.

Non-vitamin K antagonist oral anticoagulants (NOACs) post-percutaneous coronary intervention: a network meta-analysis

BACKGROUND

Clinicians must balance the risks of bleeding and thrombosis after percutaneous coronary intervention (PCI) in people with an indication for anticoagulation. The potential of non-vitamin K antagonists (NOACs) to prevent bleeding complications is promising, but evidence remains limited.

OBJECTIVES

To review the evidence from randomised controlled trials assessing the efficacy and safety of non-vitamin K antagonist oral anticoagulants (NOACs) compared to vitamin K antagonists post-percutaneous coronary intervention (PCI) in people with an indication for anticoagulation.

SEARCH METHODS

We identified studies by searching CENTRAL, MEDLINE, Embase, the Conference Proceedings Citation Index - Science and two clinical trials registers in February 2019. We checked bibliographies of identified studies and applied no language restrictions.

SELECTION CRITERIA

We searched for randomised controlled trials (RCT) that compared NOACs and vitamin K antagonists for people with an indication for anticoagulation who underwent PCI.

DATA COLLECTION AND ANALYSIS

Two review authors independently checked the results of searches to identify relevant studies, assessed each included study, and extracted study data. We conducted random-effects, pairwise analyses using Review Manager 5 and network meta-analyses (NMA) using the R package 'netmeta'. We ranked competing treatments by P scores, which are derived from the P values of all pairwise comparisons, and allow ranking of treatments on a continuous 0 to 1 scale.

MAIN RESULTS

We identified nine RCTs that met the inclusion criteria, but four were ongoing trials, and were not included in this analysis. We included five RCTs, with 8373 participants, in the NMA (two RCTs compared apixaban to a vitamin K antagonist, two RCTs compared rivaroxaban to a vitamin K antagonist, and one RCT compared dabigatran to a vitamin K antagonist). Very low- to moderate-certainty evidence suggests little or no difference between NOACs and vitamin K antagonists in death from cardiovascular causes (not reported in the dabigatran trial), myocardial infarction, stroke, death from any cause, and stent thrombosis. Apixaban (RR 0.85, 95% CI 0.77 to 0.95), high dose rivaroxaban (RR 0.86, 95% CI 0.74 to 1.00), and low dose rivaroxaban (RR 0.80, 95% CI 0.68 to 0.92) probably reduce the risk of recurrent hospitalisation compared with vitamin K antagonists. No studies looked at health-related quality of life. Very low- to moderate-certainty evidence suggests that NOACs may be safer than vitamin K antagonists in terms of bleeding. Both high dose dabigatran (RR 0.53, 95% CI 0.29 to 0.97), and low dose dabigatran (RR 0.38, 95% CI 0.21 to 0.70) may reduce major bleeding more than vitamin K antagonists. High dose dabigatran (RR 0.83, 95% CI 0.72 to 0.96), low dose dabigatran (RR 0.66, 95% CI 0.58 to 0.75), apixaban (RR 0,67 , 95% Cl 0.51 to 0.88), high dose rivaroxaban (RR 0.66, 95% CI 0.52 to 0.83), and low dose rivaroxaban (RR 0.71, 95% CI 0.57 to 0.88) probably reduce non-major bleeding more than vitamin K antagonists. The results from the NMA were inconclusive between the different NOACs for all primary and secondary outcomes.

AUTHORS' CONCLUSIONS

Very low- to moderate-certainty evidence suggests no meaningful difference in efficacy outcomes between non-vitamin K antagonist oral anticoagulants (NOAC) and vitamin K antagonists following percutaneous coronary interventions (PCI) in people with non-valvular atrial fibrillation. NOACs probably reduce the risk of recurrent hospitalisation for adverse events compared with vitamin K antagonists. Low- to moderate-certainty evidence suggests that dabigatran may reduce the rates of major and non-major bleeding, and apixaban and rivaroxaban probably reduce the rates of non-major bleeding compared with vitamin K antagonists. Our network meta-analysis did not show superiority of one NOAC over another for any of the outcomes. Head to head trials, directly comparing NOACs against each other, are required to provide more certain evidence.

Rationale and design of the Onyx ONE global randomized trial: A randomized controlled trial of high-bleeding risk patients after stent placement with 1 month of dual antiplatelet therapy

BACKGROUND AND RATIONALE

Polymer-free drug-eluting stent (DES) implantation in combination with 1-month dual antiplatelet therapy (DAPT) has shown superior safety and efficacy outcomes compared with bare-metal stents among patients with high-bleeding risk (HBR) treated with 1-month DAPT. The safety and efficacy of the newer-generation durable-polymer DES Resolute Onyx compared with polymer-free DES among HBR patients treated with 1-month DAPT is unknown.

TRIAL DESIGN

The Onyx ONE global randomized trial is an international, prospective, randomized, blinded, controlled study enrolling HBR patients undergoing percutaneous coronary intervention. The trial will randomize up to 2,000 patients in a 1:1 fashion to receive either the durable-polymer Resolute Onyx DES or the polymer-free Biosensors BioFreedom DES. After index procedure, patients in both arms will be treated with 1 month of DAPT (aspirin and oral P2Y12 inhibitor), followed by single antiplatelet therapy thereafter. The primary end point is the composite end point of cardiac death, myocardial infarction, or stent thrombosis at 1-year follow-up. The powered secondary end point is target lesion failure (defined as the composite of cardiac death, target vessel myocardial infarction, or clinically driven target lesion revascularization) at 1 year. Patient follow-up is planned for 1, 2, and 6 months and 1 and 2 years after the procedure.

CONCLUSIONS

The Onyx ONE global randomized trial is the first study to directly compare the safety and efficacy of a durable polymer DES (Resolute Onyx) with a polymer-free DES (BioFreedom) in HBR patients treated with 1 month of DAPT.

Combining mathematical modelling with in vitro experiments to predict in vivo drug-eluting stent performance

In this study, we developed a predictive model of in vivo stent based drug release and distribution that is capable of providing useful insights into performance. In a combined mathematical modelling and experimental approach, we created two novel sirolimus-eluting stent coatings with quite distinct doses and release kinetics. Using readily measurable in vitro data, we then generated parameterised mathematical models of drug release. These were then used to simulate in vivo drug uptake and retention. Finally, we validated our model predictions against data on drug kinetics and efficacy obtained in a small in vivo evaluation. In agreement with the in vivo experimental results, our mathematical model predicted consistently higher sirolimus content in tissue for the higher dose stents compared with the lower dose stents. High dose stents resulted in statistically significant improvements in three key efficacy measures, providing further evidence of a basic relationship between dose and efficacy within DES. However, our mathematical modelling suggests a more complex relationship is at play, with efficacy being dependent not only on delivering an initial dose of drug sufficient to achieve receptor saturation, but also on the consequent drug release rate being tuned to ensure prolonged saturation. In summary, we have demonstrated that our combined in vitro experimental and mathematical modelling framework may be used to predict in vivo DES performance, opening up the possibility of an in silico approach to optimising the drug release profile and ultimately the effectiveness of the device.

Newer-generation Metallic Stents: Design, Performance Characteristics, and Outcomes

Several new coronary stents have been, or soon will be, introduced in the United States. These stents incorporate certain characteristics, such as polymer-free drug coatings, ultrathin stent struts, bioresorbable polymers, and composite materials, that address currently unmet clinical needs to enhance acute stent performance, improve longer-term clinical outcomes, and obviate obligatory prolonged dual antiplatelet therapy. This article reviews the key and novel features of these stents.

The influence of Elixhauser comorbidity index on percutaneous coronary intervention outcomes

BACKGROUND

Clinical outcomes with respect to the evolution of comorbidity burden in national cohorts of patients undergoing PCI have not been reported.

OBJECTIVES

We sought to explore the association between comorbidity burden and periprocedural outcomes in patients treated with PCI in the National Inpatient Sample.

METHODS

6,601,526 PCI procedures were identified between 2004 and 2014 and comorbidities were defined by the Elixhauser classification system (ECS) consisting of 30 comorbidity measures. Endpoints included in-hospital mortality, periprocedural complications, length of stay and cost. Patients were classified based on their ECS in five categories (ECS I < 0, ECS II = 0, ECS III = 1-5, ECS IV = 6-13, and ECS V ≥ 14).

RESULTS

Patients with a score over 13 had a fivefold increase in the odds of mortality (OR: 5.13, 95% CI: 4.76-5.54), major bleeding (OR: 11.46, 95% CI: 10.66-12.33) and doubled the hospitalization costs ($31,452 vs $17.566).

CONCLUSIONS

Our study of over six million PCI procedures demonstrates that patients with the greatest comorbid burden (as defined by an ECS of >13) have a fivefold increase risk of in-hospital mortality, a fourfold increase in in-hospital periprocedural complications and an 11-fold increase in major bleeding events once differences in baseline patient characteristics are adjusted for. In addition, ECS significantly impacts the length of stay and doubles the healthcare costs. Comorbid burden is an important predictor of poor outcomes after PCI and should be considered as part of the decision-making processes in patients undergoing PCI.

Arterial events in cancer patients-the case of acute coronary thrombosis

Patients with cancer are at high risk for both venous and arterial thrombotic complications. A variety of factors account for the greater thrombotic risk, including the underlying malignancy and numerous cancer-directed therapies. The occurrence of an acute thrombotic event in patients with cancer is associated with substantial morbidity and mortality. Acute coronary syndrome (ACS) represents a particularly important cardiovascular complication in cancer patients. With cardio-vascular risk factors becoming more prevalent in an aging cancer population that is surviving longer, questions pertaining to the appropriate management of vascular toxicity are likely to assume even greater value in the coming years. In this article, we review the current understanding of ACS in patients with cancer. The predisposition to thrombosis in a malignant host and the cancer treatments most commonly associated with vascular toxicity are reviewed. Risk prediction and management strategies are discussed, and discrepancies in the clinical evidence are highlighted.