Direct oral anticoagulants and cardiovascular prevention in patients with nonvalvular atrial fibrillation

The relationship between atrial fibrillation and coronary artery disease: Understanding common denominators

Atrial fibrillation (AF) and coronary artery disease (CAD) are highly prevalent cardiovascular conditions. The coexistence of both diseases is common as they share similar risk factors and common pathophysiological characteristics. Systemic inflammatory conditions are associated with an increased incidence of both AF and CAD. The presence of both entities increases the incidence of complications and adverse outcomes. Furthermore, their coexistence poses challenges for the management of patients, particularly with respect to anticoagulation and rhythm management. In this review, we aim to better understand the relationship between AF and CAD by detailing basic molecular pathophysiology, assessing therapeutic guidelines, and describing interactions between the two conditions.

Non-embolic outcomes in patients with cardiovascular disease and atrial fibrillation treated with rivaroxaban

Aim: It is not well known how comorbidities may change the prognosis of atrial fibrillation (AF) patients. This study was aimed to analyze the impact of cardiovascular disease on this population. Materials & methods: EMIR was a multicenter, prospective study, including 1433 AF patients taking rivaroxaban for ≥6 months. Data were analyzed according to the presence of vascular disease. Results: Coronary artery disease was detected in 16.4%, peripheral artery disease/aortic plaque in 6.7%, vascular disease in 28.3%. Patients with coronary artery disease had higher rates (per 100 patient-years) of major adverse cardiovascular events (2.98 vs 0.71; p < 0.001) and cardiovascular death (1.79 vs 0.41; p = 0.004). Those with vascular disease had higher rates of thromboembolic events (1.47 vs 0.44; p = 0.007), major adverse cardiovascular events (2.03 vs 0.70; p = 0.004), and cardiovascular death (1.24 vs 0.39; p = 0.025). Patients with peripheral artery disease/aortic plaque had similar rates. Conclusion: AF patients with vascular disease have a higher risk of non-embolic outcomes.

Different DOACs Control Inflammation in Cardiac Ischemia-Reperfusion Differently

RATIONALE

While thrombin is the key protease in thrombus formation, other coagulation proteases, such as fXa (factor Xa) or aPC (activated protein C), independently modulate intracellular signaling via partially distinct receptors.

OBJECTIVES

To study the differential effects of fXa or fIIa (factor IIa) inhibition on gene expression and inflammation in myocardial ischemia-reperfusion injury.

METHODS AND RESULTS

Mice were treated with a direct fIIa inhibitor (fIIai) or direct fXa inhibitor (fXai) at doses that induced comparable anticoagulant effects ex vivo and in vivo (tail-bleeding assay and FeCl₃-induced thrombosis). Myocardial ischemia-reperfusion injury was induced via left anterior descending ligation. We determined infarct size and in vivo aPC generation, analyzed gene expression by RNA sequencing, and performed immunoblotting and ELISA. The signaling-only 3K3A-aPC variant and inhibitory antibodies that blocked all or only the anticoagulant function of aPC were used to determine the role of aPC. Doses of fIIai and fXai that induced comparable anticoagulant effects resulted in a comparable reduction in infarct size. However, unbiased gene expression analyses revealed marked differences, including pathways related to sterile inflammation and inflammasome regulation. fXai but not fIIai inhibited sterile inflammation by reducing the expression of proinflammatory cytokines (IL [interleukin]-1β, IL-6, and TNFα [tumor necrosis factor alpha]), as well as NF-κB (nuclear factor kappa B) and inflammasome activation. This anti-inflammatory effect was associated with reduced myocardial fibrosis 28 days post-myocardial ischemia-reperfusion injury. Mechanistically, in vivo aPC generation was higher with fXai than with fIIai. Inhibition of the anticoagulant and signaling properties of aPC abolished the anti-inflammatory effect associated with fXai, while inhibiting only the anticoagulant function of aPC had no effect. Combining 3K3A-aPC with fIIai reduced the inflammatory response, mimicking the fXai-associated effect.

CONCLUSIONS

We showed that specific inhibition of coagulation via direct oral anticoagulants had differential effects on gene expression and inflammation, despite comparable anticoagulant effects and infarct sizes. Targeting individual coagulation proteases induces specific cellular responses unrelated to their anticoagulant effect.

Rivaroxaban: searching the integral vascular protection

INTRODUCTION

Residual cardiovascular risk remains high in patients with atherosclerotic cardiovascular disease despite current antithrombotic therapy. On the other hand, patients with atrial fibrillation have an increased risk of myocardial infarction and cardiovascular death. As a result, a new antithrombotic approach appears necessary to reduce this risk. Areas covered: In this article, the role of rivaroxaban on vascular protection in patients with cardiovascular disease and/or atrial fibrillation was reviewed, with a particular focus, but not limited, on clinical trials. Expert commentary: Previous data have shown that factor Xa plays a key role in the etiopathogenesis of atherothrombosis. Experimental data suggest that rivaroxaban exhibits antiinflammatory and antioxidative stress properties, and may improve endothelial dysfunction. The COMPASS trial showed that among patients with stable atherosclerotic vascular disease, the addition of rivaroxaban 2.5 mg twice daily (vascular dose) to aspirin provided a higher cardiovascular protection than aspirin alone. In ROCKET-AF trial, compared with warfarin, rivaroxaban 20 mg once daily (15 mg if moderate renal dysfunction) (anticoagulant dose) was, at least, as effective as warfarin for the prevention of stroke or systemic embolism among patients with nonvalvular atrial fibrillation, with a trend toward a reduction in the risk of cardiovascular outcomes. All these data suggest that rivaroxaban might have a vascular protective effect beyond its stroke/systemic embolism preventive activity.

Anticoagulant and antiplatelet therapy choices for patients with atrial fibrillation one year after coronary stenting or acute coronary syndrome

INTRODUCTION

Guidelines recommend a combined anticoagulant and antiplatelet approach for patients with atrial fibrillation (AF) after coronary stenting (CS) or acute coronary syndrome (ACS). Finding the optimal balance of reducing ischemic risk and minimizing bleeding risk is challenging. Recent trials have evaluated a variety of regimens for up to one year for AF patients after CS/ACS. Little empiric evidence exists about the best antithrombotic strategy beyond one year.

AREAS COVERED

In this review two key areas are covered. First, a summary of the overall risk and benefits of anticoagulant and antiplatelet therapy in patients with AF and CS or ACS is provided. Second, despite limited empiric evidence to guide therapeutic decisions for combined anticoagulant and antiplatelet therapy in patients with AF one year after CS/ACS we provide guidance for shared patient-physician decision making.

EXPERT OPINION

The evidence is limited. For all patients with AF and stable CAD (≥1 year after CS or ACS) the risk for thromboembolism, cardiovascular events and bleeding should be assessed individually. For patients with low bleeding risk and high risk for cardiovascular events, antiplatelet therapy might be added to anticoagulant therapy.

Usefulness of the 2MACE Score to Predicts Adverse Cardiovascular Events in Patients With Atrial Fibrillation

We investigated the incidence of nonembolic adverse events in 2 cohorts of patients with atrial fibrillation (AF) and validated the 2MACE score ([metabolic syndrome, age ≥75] [doubled]; [myocardial infarction or revascularization, congestive heart failure {HF}, and stroke, transient ischemic attack or thromboembolism]) as predictor of major adverse cardiovascular events (MACEs). We recruited 2,630 patients with AF from 2 different cohorts (Murcia AF and FANTASIIA). The 2MACE score was calculated, and during a median of 7.2 years (Murcia AF cohort) and 1.01 years (FANTASIIA) of follow-up, we recorded all nonembolic adverse events and MACEs (composite of nonfatal myocardial infarction or revascularization and cardiovascular death). Receiver operating characteristic curves comparison, reclassification and discriminatory analyses, and decision curve analyses were performed to compare predictive ability and clinical usefulness of the 2MACE score against CHA₂DS₂-VASc. During follow-up, there were 65 MACEs in the Murcia cohort and 60 in the FANTASIIA cohort. Events rates were higher in the high-risk category (score ≥3) (1.94%/year vs 0.81%/year in the Murcia cohort; 6.01%/year vs 1.71%/year, in FANTASIIA, both p <0.001). The predictive performance of 2MACE according to the receiver operating characteristic curve was significantly higher than that of CHA₂DS₂-VASc (0.662 vs 0.618, p = 0.008 in the Murcia cohort; 0.656 vs 0.565, p = 0.003 in FANTASIIA). Decision curve analyses demonstrated improved clinical usefulness of the 2MACE compared with the CHA₂DS₂-VASc score. In conclusion, in "real-world" patients with AF, the 2MACE score is a good predictor of MACEs. A score ≥3 should be used to categorize patients at "high risk," in identifying patients at risk of MACE.