Обзор американских кардиологических журналов за неделю (ссылки)

[Chevychelov]

Title: Predictors for New-Onset Complete Heart Block After Transcatheter Aortic Valve Implantation
Topic: Cardiovascular Surgery
Date Posted: 6/4/2010
Author(s): Bleiziffer S, Ruge H, Hцrer J, et al.
Citation: JACC Cardiovasc Interv 2010;3:524-530.
Clinical Trial: No
Study Question: What are the risk factors for new-onset atrioventricular (AV) block requiring pacemaker (PM) implantation after transcatheter aortic valve implantation (TAVI)?
Methods: Between June 2007 and January 2009, 200 elderly patients >75 years of age underwent TAVI for symptomatic high-grade aortic stenosis at the author’s institution. For logistic regression analysis, they included 159 patients (mean age: 81 ± 6 years, EuroSCORE: 22 ± 13%) who underwent TAVI (n = 116 transfemoral, n = 4 via subclavian artery, n = 37 transapical, n = 2 transaortic) between June 2007 and January 2009 and who had no previously implanted PM.
Results: Thirty-five patients (22%) developed new-onset postoperative AV block with the need of PM implantation. Logistic regression revealed a twofold increased risk for new-onset AV block in patients in whom a large valve is implanted in a small annulus (32% pacemaker implantations; odds ratio [OR], 2.378; p = NS), a fourfold increased risk with the implantation of the CoreValve (Medtronic, Minneapolis, MN) versus the Edwards Sapien valve (Edwards Lifesciences, Irvine, CA) (27% pacemaker implantations; OR, 3.781; p = NS), and a fivefold increased risk for patients who exhibit an AV block episode instantly during the implantation procedure (49% pacemaker implantations; OR, 4.819; p = 0.001). Pre-existing ECG alterations were not identified as risk factors for AV block after TAVI.
Conclusions: The authors concluded that conduction tissue impairment is provoked by mechanical compression with large prostheses in smaller annuli or in the larger area of the CoreValve covering the outflow tract.
Perspective: This analysis suggests that valve-related AV block requiring pacemaker implantation is a frequent finding after TAVI that may occur in up to 22% of patients. The most important finding from this study is that patients who experience an AV block instantly in the operating room after balloon valvuloplasty or after valve deployment exhibit an almost fivefold risk to develop permanent AV block with the eventual need for pacemaker implantation. It appears that conduction tissue impairment is provoked by mechanical compression with relatively large balloons and prostheses in smaller annuli or in the larger area of the CoreValve covering the outflow tract. Continuous postoperative ECG monitoring to detect high-grade AV block for at least 3 days appears prudent in all patients, and until discharge in patients with increased risk for this complication. A pacemaker may be indicated if episodes of high-grade AV block were diagnosed during the postoperative course. Debabrata Mukherjee, M.D., F.A.C.C.