Key result
Transcatheter aortic valve implantation with the Medtronic CoreValve System was associated with new conduction abnormalities in 82% of patients, mostly occurring before valve implantation.
Why the study?
What is the timing and mechanism of new conduction abnormalities during TAVI with the Medtronic CoreValve System in patients with aortic stenosis?
Observational (n=65)
What is the timing and mechanism of new conduction abnormalities during TAVI with the Medtronic CoreValve System in patients with aortic stenosis?
More than half of new conduction abnormalities during TAVI with the Medtronic CoreValve System occur before actual valve implantation, particularly after balloon valvuloplasty, suggesting balloon sizing plays a mechanistic role.
Observational timing of new CAs during CoreValve TAVI may guide monitoring; leaves open causal mechanisms and prospective trials.
AIMS: New-onset left bundle branch block (LBBB) and complete atrioventricular block (AV3B) frequently occur following transcatheter aortic valve implantation (TAVI). We sought to determine the timing and potential mechanisms of new conduction abnormalities (CAs) during TAVI, using the Medtronic CoreValve System (MCS). METHODS AND RESULTS: Sixty-five consecutive patients underwent TAVI with continuous 12-lead ECG analysis. New CAs were defined by the occurrence of LBBB, RBBB, and/or AV3B after the following pre-defined time points: (i) crossing of valve with stiff wire, (ii) positioning of balloon catheter in the aortic annulus, (iii) balloon valvuloplasty, (iv) positioning of MCS in the left ventricular outflow tract (LVOT), (v) expansion of MCS, (vi) removal of all catheters. A new CA occurred during TAVI in 48 patients (74%) and after TAVI in 5 (8%). Of the 48 patients with procedural CAs, a single new CA occurred in 43 patients (90%) and two types of CAs in 5 (10%). A new LBBB was seen in 40 patients (83%), AV3B in 9 (19%), and RBBB in 4 (8%). The new CA first occurred-in descending order of frequency-after balloon valvuloplasty in 22 patients (46%), MCS expansion in 14 (29%), MCS positioning in 6 (12%), positioning of balloon catheter in 3 (6%), wire-crossing of aortic valve in 2 (4%), and after catheter removal in 1 patient (2%). Patients who developed a new CA during balloon valvuloplasty had a significantly higher balloon/annulus ratio than those who did not (1.10±0.10 vs. 1.03±0.11, P=0.030). No such relationship was found with the valve/annulus ratio. CONCLUSION: Transcatheter aortic valve implantation with the MCS was associated with new CAs in 82% of which more than half occurred before the actual valve implantation. It remains to be elucidated by dedicated studies whether new CAs can be reduced by appropriate balloon sizing-a precept that also holds for valve size given the observed directional signal of the valve size/aortic annulus ratio.
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Nuis et al. (2011) conducted an observational in aortic stenosis (n=65). Transcatheter aortic valve implantation with the Medtronic CoreValve System was evaluated on New conduction abnormalities (LBBB, RBBB, and/or AV3B) during and after TAVI. Transcatheter aortic valve implantation with the Medtronic CoreValve System was associated with new conduction abnormalities in 82% of patients, mostly occurring before valve implantation.
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