Quality and predictors of anticoagulant control with vitamin K antagonist for stroke prevention in atrial fibrillation

One-year risks of stroke and mortality in patients with atrial fibrillation from different clinical settings: The Gulf SAFE registry and Darlington AF registry

BACKGROUND

Differences exist in oral anticoagulation (OAC) use between different populations with atrial fibrillation (AF), which may be associated with varying outcomes.

PURPOSE

We aimed to provide patient level comparisons of two cohorts of patients with AF, from the United Kingdom (UK) and Middle East (ME).

METHODS

The clinical characteristics, prescription of OAC, one-year risk of stroke and mortality were compared between individual patients with AF included into the Darlington AF registry (UK, n = 2258) and the Gulf SAFE (Survey of atrial fibrillation events) registry (ME, n = 1740).

RESULTS

A high percentage of patients from the Darlington registry were candidates for OAC (i.e., CHA₂DS₂-VASc score ≥2 in males or ≥3 in females; 82.0% in Darlington and 57.1% in Gulf SAFE). OAC use was suboptimal (52.0% in Darlington vs 58.4% in Gulf SAFE). One-year rates of stroke and mortality were high in both populations, especially in those with CHA₂DS₂-VASc score ≥2 in males and ≥3 in females (Darlington vs. Gulf SAFE: 3.51% vs. 5.63 for stroke; 11.4% vs. 16.8% for mortality). On multivariate analyses, female sex and previous stroke were independently associated with stroke events; while elderly age, female sex, vascular disease and heart failure were independent risk factors for mortality (all p < 0.05). Patients from Gulf SAFE registry had higher risk of stroke (odds ratio, 2.18 [1.47-3.23]) and mortality (odds ratio, 1.67 [1.31-2.14]) compared with those from Darlington registry. The CHA₂DS₂-VASc score showed good discrimination in predicting one-year risk of stroke (area under curve, 0.71 [0.65-0.76] in non-anticoagulated patients) and mortality (area under curve, 0.70 [0.68-0.72]) in the whole study population, as well as in Darlington or Gulf SAFE registry separately.

CONCLUSIONS

Stroke prevention was generally suboptimal in patient cohorts from the two registries, which was associated with high one-year risks of stroke and mortality, particularly so among patients from the Gulf SAFE registry. The higher risks for stroke and mortality in AF patients from the Gulf SAFE registry (compared to a UK cohort) merit further implementation of cardiovascular prevention strategies.

Stroke prevention in atrial fibrillation: Past, present and future

Concepts and our approaches to stroke prevention in atrial fibrillation (AF) have changed markedly over the last decade. There has been an evolution over the approach to stroke and bleeding risk assessment, as well as new treatment options. An increasing awareness of AF has led to calls to improve the detection of and population screening for AF. Stroke and bleeding risk assessment continues to evolve, and the ongoing debate on balance between simplicity and practicality, against precision medicine will continue. In this review article, we provide an overview of past, present and the (likely) future concepts and approaches to stroke prevention in AF. We propose three simple steps (the Birmingham ‘3-step’) that offers a practical management pathway to help streamline and simplify decision-making for stroke prevention in patients with AF.

Note: The review process for this paper was fully handled by Christian Weber, Editor in Chief.

Long-term bleeding risk prediction in ‘real world’ patients with atrial fibrillation: Comparison of the HAS-BLED and ABC-Bleeding risk scores

Risk scores in patients with atrial fibrillation (AF) based on clinical factors alone generally have only modest predictive value for predicting high risk patients that sustain events. Biomarkers might be an attractive prognostic tool to improve bleeding risk prediction. The new ABCBleeding score performed better than HAS-BLED score in a clinical trial cohort but has not been externally validated. The aim of this study was to analyze the predictive performance of the ABC-Bleeding score compared to HAS-BLED score in an independent “real-world” anticoagulated AF patients with long-term follow-up. We enrolled 1,120 patients stable on vitamin K antagonist treatment. The HAS-BLED and ABC-Bleeding scores were quantified. Predictive values were compared by c-indexes, IDI, NRI, as well as decision curve analysis (DCA). Median HAS-BLED score was 2 (IQR 2–3) and median ABC-Bleeding was 16.5 (IQR 14.3–18.6). After 6.5 years of follow-up, 207 (2.84%/year) patients had major bleeding events, of which 65 (0.89%/year) had intracranial haemorrhage (ICH) and 85 (1.17%/year) had gastrointestinal bleeding events (GIB). The c-index of HAS-BLED was significantly higher than ABC-Bleeding for major bleeding (0.583 vs 0.518; p=0.025), GIB (0.596 vs 0.519; p=0.017) and for the composite of ICH-GIB (0.593 vs 0.527; p=0.030). NRI showed a significant negative reclassification for major bleeding and for the composite of ICH-GIB with the ABC-Bleeding score compared to HAS-BLED. Using DCAs, the use of HAS-BLED score gave an approximate net benefit of 4% over the ABC-Bleeding score. In conclusion, in the first “real-world” validation of the ABC-Bleeding score, HAS-BLED performed significantly better than the ABC-Bleeding score in predicting major bleeding, GIB and the composite of GIB and ICH.

Note: The review process for this manuscript was fully handled by Christian Weber, Editor in Chief.

Supplementary Material to this article is available online at www.thrombosis-online.com.

Hypertension and Atrial Fibrillation: An Intimate Association of Epidemiology, Pathophysiology, and Outcomes

Atrial fibrillation (AF) is the most prevalent sustained arrhythmia found in clinical practice. AF rarely exists as a single entity but rather as part of a diverse clinical spectrum of cardiovascular diseases, related to structural and electrical remodeling within the left atrium, leading to AF onset, perpetuation, and progression. Due to the high overall prevalence within the AF population arterial hypertension plays a significant role in the pathogenesis of AF and its complications. Fibroblast proliferation, apoptosis of cardiomyocytes, gap junction remodeling, accumulation of collagen both in atrial and ventricular myocardium all accompany ageing-related structural remodeling with impact on electrical activity. The presence of hypertension also stimulates oxidative stress, systemic inflammation, rennin-angiotensin-aldosterone and sympathetic activation, which further drives the remodeling process in AF. Importantly, both hypertension and AF independently increase the risk of cardiovascular and cerebrovascular events, e.g., stroke and myocardial infarction. Given that both AF and hypertension often present with limited on patient wellbeing, treatment may be delayed resulting in development of complications as the first clinical manifestation of the disease. Antithrombotic prevention in AF combined with strict blood pressure control is of primary importance, since stroke risk and bleeding risk are both greater with underlying hypertension.