Long-term cardiovascular outcomes in patients with atrial fibrillation and atherothrombosis in the REACH Registry
Introduction
It has been estimated that 2.2 million people in the United States, 4.5 million people in the European Union [1] and 8 million people in China [2] suffer from atrial fibrillation (AF) with a prevalence that is estimated to at least double within the next 50 years [3]. Thromboembolism, primarily ischemic stroke, is the most feared and devastating complication of AF [4], [5], [6], [7], [8], occurs in approximately 5% of patients per year without anticoagulation (a 2 to 7 fold increase in risk) [9], [10], [11].
Conditions associated with AF are also markers of global cardiovascular risk, therefore, it is not surprising that AF is common in patients with stable atherosclerosis and those who have suffered an ischemic event [12]. Coronary artery disease is present in ≥ 20% of the AF population [13], [14] and AF complicating acute coronary syndromes (ACS) is associated with a markedly increased in-hospital and long-term mortality [15]. The presence of atherosclerotic vascular disease may also contribute to stroke risk. In AF patients, an increased risk of stroke and thromboembolism is seen in patients with a previous myocardial infarction (MI) and/or peripheral artery disease [16], [17], [18]. In fact, in many patients it is postulated that AF is a marker or surrogate of increased vascular stiffness causing diastolic dysfunction, atrial volume overload and increased vulnerability to AF [19], [20], [21].
Despite the extensive overlap between AF and atherosclerosis and the possibility that patients with both conditions represent a very high risk group with a synergistic increase in both ischemic and thromboembolic events, there are very few large, well-characterized studies that provide long-term outcomes. The international Reduction of Atherothrombosis for Continued Health (REACH) Registry provides an opportunity to examine the impact of AF in a large, international population of “real world” patients with various manifestations of atherosclerosis, spanning from asymptomatic adults with risk factors, to patients with stable atherosclerosis, to those with prior ischemic events [22], [23], [24], [25], [26]. One-year data from the REACH Registry demonstrate an increased risk of fatal and non-fatal outcomes in patients with AF [27]. The present analysis seeks to provide long-term data regarding the prognosis and utilization rates of evidence-based antithrombotic therapies in this vulnerable population.
Section snippets
Methods
The authors of this manuscript have certified that they comply with the Principles of Ethical Publishing in the International Journal of Cardiology.
Results
Among the 68,236 patients enrolled in the REACH registry, 44,518 were eligible for inclusion in this analysis (4 year outcomes data and AF present or absent confirmed at baseline). The prevalence of baseline AF in the entire cohort was 10.3% (n = 4582) and was consistent in the main symptomatic subgroups: CAD 12.0%, CVD 13.2%, PAD 10.3%, and lower in the RFO group: 6.2%.
The baseline characteristics of patients with and without AF are shown in Table 1. As expected, patients with AF were older (72.6
Discussion
This analysis of a large, international registry demonstrates that AF is a frequent companion to atherosclerosis and the presence of both is a powerful predictor of adverse cardiovascular events over a 4-year follow-up period. Despite a markedly increased risk, this vulnerable population is routinely undertreated with anticoagulant therapy.
This study supports that the prevalence of AF is higher in patients with atherothrombosis compared to the general population (age matched 5–7%) [3], [30],
Conclusions
In conclusion, AF is prevalent in patients across the spectrum of atherosclerosis and the presence of both conditions imparts a substantial long-term risk of cardiovascular events. This large, international study underscores that these vulnerable, high-risk patients often do not receive guideline recommended care likely due to the complexity of their management and the lack of data informing clinicians on the optimal treatment approach. Although a new era of anticoagulation therapy is on the
References (44)
- et al.
Epidemiology, risk factors for stroke, and management of atrial fibrillation in China
J Am Coll Cardiol
(2008) - et al.
Relations between left atrial appendage blood flow velocity, spontaneous echocardiographic contrast and thromboembolic risk in vivo
J Am Coll Cardiol
(1994) - et al.
Risk of stroke in non-rheumatic atrial fibrillation
Lancet
(1987) - et al.
The natural history of atrial fibrillation: incidence, risk factors, and prognosis in the Manitoba Follow-Up Study
Am J Med
(1995) - et al.
Impact of vascular disease in predicting stroke and death in patients with atrial fibrillation: the Danish Diet, Cancer and Health cohort study
J Thromb Haemost
(2011) - et al.
Risk factors and incidence of ischemic stroke in Taiwanese with nonvalvular atrial fibrillation—a nationwide database analysis
Atherosclerosis
(2011) - et al.
Left ventricular diastolic dysfunction as a predictor of the first diagnosed nonvalvular atrial fibrillation in 840 elderly men and women
J Am Coll Cardiol
(2002) - et al.
Prediction of risk for first age-related cardiovascular events in an elderly population: the incremental value of echocardiography
J Am Coll Cardiol
(2003) The left atrium: a biomarker of chronic diastolic dysfunction and cardiovascular disease risk
J Am Coll Cardiol
(2003)- et al.
Refining clinical risk stratification for predicting stroke and thromboembolism in atrial fibrillation using a novel risk factor-based approach: the euro heart survey on atrial fibrillation
Chest
(2010)
Factors influencing physicians' reported use of anticoagulation therapy in nonvalvular atrial fibrillation: a cross-sectional survey
Clin Ther
Effects of pretreatment with clopidogrel and aspirin followed by long-term therapy in patients undergoing percutaneous coronary intervention: the PCI-CURE study
Lancet
Long-term cost effectiveness of early and sustained dual oral antiplatelet therapy with clopidogrel given for up to one year after percutaneous coronary intervention results: from the Clopidogrel for the Reduction of Events During Observation (CREDO) trial
J Am Coll Cardiol
Patient characteristics associated with the choice of triple antithrombotic therapy in acute coronary syndromes
Am J Cardiol
Does warfarin for stroke thromboprophylaxis protect against MI in atrial fibrillation patients?
Am J Med
2011 ACCF/AHA/HRS focused updates incorporated into the ACC/AHA/ESC 2006 guidelines for the management of patients with atrial fibrillation: a report of the American College of Cardiology Foundation/American Heart Association Task Force on practice guidelines
Circulation
Secular trends in incidence of atrial fibrillation in Olmsted County, Minnesota, 1980 to 2000, and implications on the projections for future prevalence
Circulation
Clinical implications and factors related to left atrial spontaneous echo contrast in chronic nonvalvular atrial fibrillation
Cardiology
Transthoracic echo/Doppler in the identification of patients with chronic non-valvular atrial fibrillation at risk for thromboembolic events
Eur Heart J
Plasma von Willebrand factor and soluble p-selectin as indices of endothelial damage and platelet activation in 1321 patients with nonvalvular atrial fibrillation: relationship to stroke risk factors
Circulation
Prognostic value of plasma von Willebrand factor and soluble P-selectin as indices of endothelial damage and platelet activation in 994 patients with nonvalvular atrial fibrillation
Circulation
Atrial fibrillation as an independent risk factor for stroke: the Framingham Study
Stroke
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- 1
A complete list of the REACH Registry Investigators appears in JAMA. 2006;295:180-189.