Navigating the treacherous waters of antithrombotic therapies in patients with atrial fibrillation and coronary artery disease: Lessons from AUGUSTUS

Direct-Acting Oral Anticoagulants in Atrial Fibrillation: What's New in the Literature

Atrial fibrillation (AF) is considered the most common sustained cardiac arrhythmia, and it is associated with a significant risk of adverse events, especially ischemic stroke. Oral anticoagulation is the cornerstone for stroke prevention in AF; for many years, only vitamin K antagonists were used for this purpose, with an absolute risk reduction >60%. However, these agents have limitations, such as narrow therapeutic margins and drug-food and drug-drug interactions. More recently, 4 direct-acting oral anticoagulants (DOACs)-non-vitamin K antagonists-have become available for patients with AF: dabigatran, rivaroxaban, apixaban, and edoxaban. In addition to a comparable efficacy to warfarin in large randomized controlled trials, DOACs were found to promote a lower risk of intracranial bleeding. The strategic dosage and lack of need for periodic prothrombin-time testing make their use attractive, especially for primary or secondary prevention of stroke in older adults. Furthermore, among patients with AF presenting with acute coronary syndrome or undergoing percutaneous coronary intervention, apixaban is associated with a reduction in serious bleeding events when compared with warfarin. On the other hand, there is no evidence of benefit of DOACs in patients with mechanical prosthetic valves or moderate/severe mitral stenosis. Furthermore, the suitability of DOACs in patients with liver disease is still poorly understood, and their safety in patients requiring renal replacement therapy remains uncertain. This review provides an overview of the main trials of DOACs, their pharmacology and safety profile, clinical implications, and best indications in light of the current evidence.

Optimal Antithrombotic Regimens for Patients With Atrial Fibrillation Undergoing Percutaneous Coronary Intervention: An Updated Network Meta-analysis

Importance

Antithrombotic treatment in patients with atrial fibrillation (AF) and percutaneous coronary intervention (PCI) presents a balancing act with regard to bleeding and ischemic risks.

Objectives

To evaluate the safety and efficacy of 4 antithrombotic regimens by conducting an up-to-date network meta-analysis and to identify the optimal treatment for patients with AF undergoing PCI.

Data Sources

Online computerized database (MEDLINE).

Study Selection

Five randomized studies were included (N = 11 542; WOEST, PIONEER AF-PCI, RE-DUAL PCI, AUGUSTUS, ENTRUST-AF PCI).

Data Extraction and Synthesis

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used in this network meta-analysis, in which bayesian random-effects models were applied. The data were analyzed from September 9 to 29, 2019.

Main Outcomes and Measures

The primary safety outcome was thrombolysis in myocardial infarction (TIMI) major bleeding and the primary efficacy outcome was trial-defined major adverse cardiovascular events (MACE).

Results

The total number of participants included in the study was 11 532. The mean age of the participants ranged from 70 to 72 years, 69% to 83% were male, 20% to 26% were female, and the participants were predominantly white (>90%). Compared with vitamin K antagonists (VKA) plus dual antiplatelet therapy (DAPT) (reference), the odds ratios (ORs) (95% credible intervals) for TIMI major bleeding were 0.57 (0.31-1.00) for VKA plus P2Y12 inhibitor, 0.69 (0.40-1.16) for non-VKA oral anticoagulant (NOAC) plus DAPT, and 0.52 (0.35-0.79) for NOAC plus P2Y12 inhibitor. For MACE, using VKA plus DAPT as reference, the ORs (95% credible intervals) were 0.97 (0.64-1.42) for VKA plus P2Y12 inhibitor, 0.95 (0.64-1.39) for NOAC plus DAPT, and 1.03 (0.77-1.38) for NOAC plus P2Y12 inhibitor.

Conclusions and Relevance

The findings of this study suggest that an antithrombotic regimen of VKA plus DAPT should generally be avoided, because regimens in which aspirin is discontinued may lead to lower bleeding risk and no difference in antithrombotic effectiveness. The use of a NOAC plus a P2Y12 inhibitor without aspirin may be the most favorable treatment option and the preferred antithrombotic regimen for most patients with AF undergoing PCI.

Antithrombotic treatment in patients with atrial fibrillation undergoing coronary angioplasty: rational convincement and supporting evidence

BACKGROUND

The management of antithrombotic therapy in patients undergoing percutaneous coronary intervention (PCI) with an indication for long-term oral anticoagulant therapy (OAT) is still a matter of debate. We aim to evaluate the safety and the efficacy of dual therapy (DT) compared to triple therapy (TT) in this clinical setting.

METHODS

A study level meta-analysis and a review of randomized trials selected using PubMed, Embase, EBSCO, Cochrane database of systematic reviews, Web of Science, and abstract from major cardiology congresses. Six randomized trials with 12,156 patients evaluating the strategy of DT vs. TT in patients treated with PCI with indication for long-term OAT were included.

RESULTS

Patients treated with DT demonstrated a 45% relative reduction in the risk of TIMI major bleeding (1.71% vs. 2.99%; OR 0.55, 95% CI 0.41-0.71; P<0.0001) and TIMI minor bleeding compared to TT arm (4.67% vs 7.83%, OR 0.55 95% CI 0.39-0.78, P = 0.0007). All-cause mortality was similar in two arms (3.95% vs 3.77%, P = 0.92), as well as cardiovascular mortality (2.21% vs 2.19%, P = 0.97). DT was associated with a borderline increase of ST (1.02% vs 0.67%, P = 0.07). No significant differences were observed in occurrence of MI and stroke.

CONCLUSIONS

Our findings suggest that DT is safer than TT with regard to occurrence of major bleeding. DT with a direct oral anticoagulant plus clopidogrel at discharge could be effective in most patients, maintaining aspirin in periprocedural phase and as longer "tailored" treatment for patients at higher ischemic risk.