Percutaneous elimination of the left atrial appendage in quest for effective and safe prevention of stroke in patients with atrial fibrillation

摘要

Atrial fibrillation (Afib) has been declared epidemic on the rise in our aging population. It is estimated that roughly one quarter of now middle-aged men and women will develop Afib during their lifespan [1, 2]. The residual risk of stroke in anticoagulated patients as calculated by the CHA2DS2-VASc score ranges from 1.3% per year for a?score of 1 to 15.2% per year for a?score of 9 depending on the presence of clearly defined risk factors [3]. Cardioembolic strokes are associated with adverse prognosis as depicted by a?high rate of serious disability and mortality. The adverse prognosis may be attributable to relatively large clots that obstruct significant parts of the cerebral circulation as well as the characteristics of the affected population, which is mostly elderly, fragile, and often burdened with concomitant diseases. Thus, the need for safe and effective measures of stroke prevention in Afib patients is beyond doubt. There is a?large body of evidence demonstrating that therapy with vitamin K antagonists (VKA) reduces the risk of stroke in Afib patients roughly by 64% and ischemic stroke by 67% [4]. Furthermore, as shown in a?meta-analysis by Ruff et al. published in 2013 in The Lancet, high-dose novel oral anticoagulants (NOAC) are even more effective as compared to VKA in preventing ischemic strokes/systemic embolism with RR 0.81, 95% CI 0.73–0.91, which translates to 147 patients that need to be treated with a?NOAC instead of VKA to prevent one additional embolic event [5]. It is important to note, however, that low-dose NOAC prevented fewer ischemic strokes as compared to warfarin so only high-dose NOAC are associated with better outcomes. Consequently, European guidelines recommend that every patient with a?CHA2DS2-VASc score of 1 or more (i.e. most of the Afib population) be treated with oral anticoagulants for stroke prevention with the preference of NOAC [6]. There are two well-known downsides to oral anticoagulation, namely bleeding and compliance. The risk of bleeding on oral anticoagulants (OAC) as depicted by the HAS-BLED score ranges from less than 2% per year to more than 4% per year depending on the presence of a?number of risk factors [7]. There are data showing that in patients with a?HAS-BLED score above 3 the risk of hemorrhagic events exceeds that of thrombotic events [8]. Furthermore, in patients with unstable international normalized ratio (INR) values during treatment with VKA the risk of... View full text...