Atrial Fibrillation During or After TAVI: Incidence, Implications and Therapeutical Considerations.

Introduction: Aortic stenosis is one of the most frequent valvulopathy of modern time necessitating interventional therapy when symptoms arise and stenosis becomes severe. First line treatment has traditionally been surgical aortic valve replacement (SAVR). However in the last decade transcatheter aortic valve implantation (TAVI) with bioprosthetic valves has proved to be a sound solution for high-risk for SAVR or inoperable patients. As expected implantation of the bioprosthetic device requires administration of antiplatelet regimen to the patients for a certain period. Atrial fibrillation (AF) may occur frequently during the peri-procedural period. In this background, the occurrence of AF after device implantation may be a challenging issue.

Methods: We performed a literature search of PubMed and Embase database. Published articles reporting the incidence, clinical implications and description of antithrombotic regimen of New-onset atrial fibrillation (NOAF) in individuals undergoing TAVI were considered eligible. Incidence, Implications and Antithrombotic Regimen: The overall occurrence of NOAF is reported to be 1%-32% after TAVI. Left atrial enlargement and transapical approach constitute independent predictors for NOAF. Additionally it has been shown that patients with AF face an increased risk of death irrespective of the type of AF. Patients, with a history of AF, present greater rate of death than individuals with NOAF. NOAF is responsible for cerebrovascular events (CVE) occurring in the subacute phase (days 1-30) after the procedure. The risk of stroke/transient ischemic attack after TAVI is increased at least two fold by the presence of atrial fibrillation. Empirically, a dual antiplatelet strategy has been used for patients undergoing TAVR, including aspirin and a thienopyridine. In cases where patients are in need of oral anticoagulation after TAVI a combination of aspirin or thienopyridine with acenocoumarol has been the preferred regimen.

Discussion: Despite the continuously crescent use of TAVI for patients with symptomatic severe aortic stenosis, there are still many aspects of this procedure to be clarified. A lack of data exists from the available clinical trials regarding the appropriate anticoagulation therapy for patients with greater risk for thromboembolic events. As a result, patient's treatment remains at the discretion of the physician.

Conclusion: Limited data are available regarding the optimal therapeutic regimen in patients undergoing TAVI who need therapy for AF. Carefully designed clinical studies might further clarify the incidence and interrelation between atrial fibrillation and TAVI. The balance between the efficacy and risk of anticoagulation needs to be further clarified in patients undergoing TAVI.