Should We Abandon the Common Practice of Withholding Oral Anticoagulation?
Aims: To assess the relation between the atrial fibrillation (AF) subtype and thrombo-embolic events.
Methods and Results: The observational Euro Heart Survey on AF (2003–04) enrolled 1509 paroxysmal, 1109 persistent, and 1515 permanent AF patients, according to the 2001 American College of Cardiology, American Heart Association, and the European Society of Cardiology guidelines definitions. A 1 year follow-up was performed. Permanent AF patients had at baseline a worse stroke risk profile than paroxysmal and persistent AF patients. In paroxysmal AF, the risk for stroke, any thrombo-embolism, major bleeding and the combined endpoint of cardiovascular mortality, any thrombo-embolism, and major bleeding was comparable with persistent and permanent AF, in both univariable and multivariable analyses. Compared with AF patients without stroke, patients suffering from a stroke had a comparable frequency and duration of AF attacks, but tended to have a worse stroke risk profile at baseline. During 1 year following cardioversion, paroxysmal AF patients had a higher risk for stroke (P = 0.029) and any thrombo-embolism (P = 0.001) than persistent AF patients.
Conclusion: In the Euro Heart Survey, paroxysmal AF had a comparable risk for thrombo-embolic events as persistent and permanent AF. This observation strengthens the guideline recommendation not to consider the clinical AF subtype when deciding on anticoagulation.
The Euro Heart Survey on atrial fibrillation (AF), and also the NABOR programme, reported that contemporary paroxysmal AF patients had a lower chance for receiving oral anticoagulation (OAC) than persistent and permanent AF patients. This observation probably relates to the traditional paradigm that anticoagulation is considered less essential with short and infrequent AF episodes. However, no clear evidence exists regarding the effect of AF duration and frequency on occurrence of stroke. Is a single, long-lasting AF episode alarming? It seems plausible that a long AF duration increases the risk for thrombus formation. Furthermore, frequent ‘stopping and starting’ of AF might be of concern, given the cluster of thrombo-embolism around rhythm transition. Stroke risk is also increased directly after restoration of sinus rhythm, probably because of the mechanism of atrial stunning, which might also increase stroke risk in paroxysmal AF with frequent episodes that terminate spontaneously.
However, regardless of the significance of the duration and frequency of AF episodes, it is quite hard in daily practice to measure these variables exactly since asymptomatic episodes or periods are common. Thus, we rely on the clinical subtype of AF to estimate the effect of AF duration and frequency on stroke risk. Some studies have suggested a lower stroke risk in paroxysmal than in persistent AF. In contrast, other studies have reported a comparable stroke risk of paroxysmal to permanent AF. The largest data set is the pooled analysis of aspirin-treated paroxysmal AF subjects in the SPAF trials, which concluded that the risk of stroke in intermittent (paroxysmal) AF was comparable with permanent AF. Consequently, the 2006 guidelines of the American College of Cardiology (ACC), American Heart Association (AHA), and the European Society of Cardiology (ESC) on AF management dissuade decisions on antithrombotic treatment by clinical subtype of AF and imply paroxysmal AF subjects should be treated similarly to persistent and permanent AF.
In order to gain further insight into this issue, we report follow-up data of the Euro Heart Survey on AF, which is the first prospective observational survey to report incidence of thrombo-embolic events in relation to the ACC/AHA/ESC classification of AF type.
Abstract and Introduction
Abstract
Aims: To assess the relation between the atrial fibrillation (AF) subtype and thrombo-embolic events.
Methods and Results: The observational Euro Heart Survey on AF (2003–04) enrolled 1509 paroxysmal, 1109 persistent, and 1515 permanent AF patients, according to the 2001 American College of Cardiology, American Heart Association, and the European Society of Cardiology guidelines definitions. A 1 year follow-up was performed. Permanent AF patients had at baseline a worse stroke risk profile than paroxysmal and persistent AF patients. In paroxysmal AF, the risk for stroke, any thrombo-embolism, major bleeding and the combined endpoint of cardiovascular mortality, any thrombo-embolism, and major bleeding was comparable with persistent and permanent AF, in both univariable and multivariable analyses. Compared with AF patients without stroke, patients suffering from a stroke had a comparable frequency and duration of AF attacks, but tended to have a worse stroke risk profile at baseline. During 1 year following cardioversion, paroxysmal AF patients had a higher risk for stroke (P = 0.029) and any thrombo-embolism (P = 0.001) than persistent AF patients.
Conclusion: In the Euro Heart Survey, paroxysmal AF had a comparable risk for thrombo-embolic events as persistent and permanent AF. This observation strengthens the guideline recommendation not to consider the clinical AF subtype when deciding on anticoagulation.
Introduction
The Euro Heart Survey on atrial fibrillation (AF), and also the NABOR programme, reported that contemporary paroxysmal AF patients had a lower chance for receiving oral anticoagulation (OAC) than persistent and permanent AF patients. This observation probably relates to the traditional paradigm that anticoagulation is considered less essential with short and infrequent AF episodes. However, no clear evidence exists regarding the effect of AF duration and frequency on occurrence of stroke. Is a single, long-lasting AF episode alarming? It seems plausible that a long AF duration increases the risk for thrombus formation. Furthermore, frequent ‘stopping and starting’ of AF might be of concern, given the cluster of thrombo-embolism around rhythm transition. Stroke risk is also increased directly after restoration of sinus rhythm, probably because of the mechanism of atrial stunning, which might also increase stroke risk in paroxysmal AF with frequent episodes that terminate spontaneously.
However, regardless of the significance of the duration and frequency of AF episodes, it is quite hard in daily practice to measure these variables exactly since asymptomatic episodes or periods are common. Thus, we rely on the clinical subtype of AF to estimate the effect of AF duration and frequency on stroke risk. Some studies have suggested a lower stroke risk in paroxysmal than in persistent AF. In contrast, other studies have reported a comparable stroke risk of paroxysmal to permanent AF. The largest data set is the pooled analysis of aspirin-treated paroxysmal AF subjects in the SPAF trials, which concluded that the risk of stroke in intermittent (paroxysmal) AF was comparable with permanent AF. Consequently, the 2006 guidelines of the American College of Cardiology (ACC), American Heart Association (AHA), and the European Society of Cardiology (ESC) on AF management dissuade decisions on antithrombotic treatment by clinical subtype of AF and imply paroxysmal AF subjects should be treated similarly to persistent and permanent AF.
In order to gain further insight into this issue, we report follow-up data of the Euro Heart Survey on AF, which is the first prospective observational survey to report incidence of thrombo-embolic events in relation to the ACC/AHA/ESC classification of AF type.
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