Discordant Relationships between Systemic Inflammatory Markers and Burden of Oxidative Stress in Patients with Atrial Fibrillation

Elevated 8-isoprostane concentration is associated with thromboembolic events in patients with atrial fibrillation

BACKGROUND

Enhanced oxidative stress occurs in atrial fibrillation (AF), however its impact on the efficacy and safety of anticoagulation is unknown. We sought to evaluate whether 8-isoprostaglandin F2 (8-isoprostane) levels are associated with clinical outcomes in anticoagulated AF patients.

METHODS

In a study involving 243 AF patients (median age 69 years), we measured serum 8-isoprostane, along with prothrombotic markers, including plasma fibrin clot permeability, clot lysis time (CLT), endogenous thrombin potential (ETP), von Willebrand factor (VWF), and fibrinolytic proteins. Ischemic cerebrovascular events, major bleeding, and death were recorded during a median follow-up of 53 months while on anticoagulation, largely on non-vitamin K antagonist oral anticoagulants (NOACs).

RESULTS

Increased 8-isoprostane levels were observed in women, in patients with arterial hypertension, and those with paroxysmal or persistent AF. Patients with 8-isoprostane levels ≥559 pg/mL (the top quartile) compared with those with 8-isoprostane <250 pg/mL (the bottom quartile) had higher fibrinogen, lower VWF, higher plasminogen activator inhibitor 1, along with lower fibrin clot permeability with no difference in CHA₂DS₂-VASc score, CLT or ETP. Patients who experienced thromboembolic events (n = 20, 1.9%/year) had 48.6% higher 8-isoprostane concentrations compared to the remainder (P <0.01). Levels of 8-isoprostane >459 pg/mL based on the optimal cut-off value were associated with thromboembolic events during follow-up (hazard ratio 2.87, 95% confidence interval 1.17-7.03, P = 0.02). There were no associations between 8-isoprostane and major bleeding (2.0%/year) or all-cause mortality (1.9%/year).

CONCLUSIONS

Increased 8-isoprostane levels partly through altered fibrin clot structure are associated with thromboembolic events despite anticoagulant therapy in AF patients.

Red blood cell distribution width and atrial fibrillation

Atrial fibrillation (AF) is the most frequent arrhythmia encountered in clinical practice and is a major health problem associated with remarkable morbidity, mortality and has considerable healthcare costs. Red blood cell distribution width (RDW) reflects the heterogeneity of the volume and size of red blood cells. It is an easily measured and inexpensive index that has been associated with several cardiovascular disease states. Accumulating evidence suggests that RDW is a prognostic marker of AF in various clinical settings. In this article, we review the available data regarding the prognostic role of RDW in AF development and perpetuation in diverse disease states as well as its role on the prediction of adverse outcomes.

Red blood cell distribution width: A marker of anisocytosis potentially associated with atrial fibrillation

The incorporation of biomarkers in the actually used risk scores seem to be helpful for early identifying atrial fibrillation (AF) patients at higher risk. The aim of this critical review of the scientific literature is to investigate the potential clinical significance of red blood cell distribution width (RDW) in AF. A systematic electronic search was carried out to identify all articles describing an epidemiological association between RDW and AF in adult human populations. Data abstraction was conducted on a final number of 35 articles (13 cross-sectional, 12 prospective and 10 retrospective studies). The results of these epidemiological investigations were all virtually concordant to emphasize that an enhanced RDW value is not only a predictive factor and a marker of AF but its measurement may also be helpful for predicting the risk of developing many adverse complications in patients with AF, such as recurrence and duration of AF, hospitalization for heart failure, bleeding, left atrial thrombosis and stasis, thromboembolic events and mortality. AF patients with RDW values exceeding the local reference range may be more aggressively investigated and managed, in order to identify and attenuate the impact of possible underlying disorders causing both anisocytosis and AF.

Five-Year Change in the Renal Function After Catheter Ablation of Atrial Fibrillation

Background

Although it has been reported that renal function can improve after catheter ablation of atrial fibrillation (AF), long‐term changes in renal function and its relationship to rhythm outcomes have not yet been evaluated. We explored the 5‐year change in estimated glomerular filtration rate (eGFR) in AF patients depending on medical therapy and catheter ablation.

Methods and Results

Among 1963 patients who underwent AF catheter ablation and 14 056 with AF under medical therapy in the National Health Insurance Service database, we compared 571 with AF catheter ablation (59±10 years old, 72.3% male, and 66.5% paroxysmal AF) and 1713 with medical therapy after 1:3 propensity‐score matching. All participants had 5 years of serial eGFR data (Chronic Kidney Disease‐Epidemiology Collaboration [CKD‐EPI] method). Catheter ablation improved eGFR_5 yrs (P<0.001), but medical therapy did not. In 2284 matched patients, age (adjusted odds ratio [OR], 0.98 [0.97–0.99]; P<0.001) and AF catheter ablation (adjusted OR, 2.02 [1.67–2.46]; P<0.001) were independently associated with an improved eGFR_5 yrs. Among 571 patients who underwent AF ablation, freedom from AF/atrial tachycardia recurrence after the last AF ablation procedure was independently associated with an improved eGFR_5 yrs (adjusted OR, 1.44 [1.01–2.04]; P=0.043), especially in patients without diabetes mellitus (adjusted OR, 1.78 [1.21–2.63]; P=0.003, P for interaction=0.012). Although underlying renal dysfunction (<60 mL/min/1.73m²) was associated with atrial structural remodeling (adjusted OR, 1.05 [1.00–1.11]; P=0.046), it did not affect the AF ablation rhythm outcome.

Conclusions

AF catheter ablation significantly improved renal function over a 5‐year follow‐up, especially in patients maintaining sinus rhythm without preexisting diabetes mellitus.

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