Ventricular arrhythmias before and after transcatheter aortic valve implantation

Abstract

Purpose: Transcatheter aortic valve implantation (TAVI) is a therapeutic option for patients with severe aortic stenosis at high surgical risk. Although the procedure is associated with a reduction in total mortality, there is no data in the literature regarding the variability in the incidence of ventricular arrhythmias (VAs) after TAVI. The aim of this study is to assess the incidence of VAs before and after TAVI and to identify the prognostic value of these arrhythmias. Methods: We enrolled 239 patients at high surgical risk who underwent TAVI at our institution between June 2007 and December 2011. Eighty-two patients were excluded from our study for the following reasons: presence of permanent pacemaker (PPM) before the procedure (n=24, 10%), new PPM implant after the procedure (n=25, 10.5%), death during the period follow-up (n=31 pcs, 13%). A total of 157 patients were included in our analysis. The presence of VAs was evaluated in all patients recording a 24-hrs Holter monitoring before the procedure and after 1, 6 and 12 months. VAs were classified according to the classification of Lown in 5 grades: absence of ventricular ectopic beats (VEB) (grade 0); VEB occasional and isolated, less than 30/h (grade 1); VEB isolated and frequent higher than 30/h (grade 2); VEB multifocal (grade 3); presence of pairs (grade 4a); ventricular tachycardia (grade 4b). Results: Before the procedure, isolates VEB (grade 1-2) were present in 54.1% of patients (n=76). Among these patients, only 20 (12.7%) had frequently VEB, more than 30/h. Complex VAs (grade 3-4) were present in 22.3% of the population (multifocal VEB in 10 pts, 6.3%; pairs in 11 pts, 7%, ventricular tachycardia in 14 pts, 8.9%). One month after the procedure, we observed an increased incidence of arrhythmias of grade 2 (n 22, 17.5%), and complex arrhythmias grade 3 (n=37 pts, 23.6%). The follow-up at 6 and 12 months showed a significant reduction in the frequency of VAs in each group. In particular, after 1 year of the procedure, only 37% of patients had isolates VEB (n=41 group 1, n=6 group 2), while the frequency of complex arrhythmias was reduced to 14.6% (multifocal VEB in 11 pts, 7% couples 7 pts, 4.5% and ventricular tachycardia in 5 pts, 3.2%). Conclusion: We observed an increase in the incidence and severity of VAs immediately after TAVI. However, this increase was transient. The long-term follow-up showed a significant reduction in the frequency of complex VAs. This may be related to the benefits determined by valve replacement on left ventricular function.