Impact of of Mitral Annulus Calcifications on Risk of Conduction Disturbances after Transcatheter Aortic Valve Implantation

Background:
The impact of mitral annular (MAC) on the risk of new conduction system disorders (CSD) after transcatheter aortic valve implantation (TAVI) remains unclear.

Methods:
168 consecutive patients with severe symptomatic aortic valve stenosis (mean age 79 ± 7 y, 49 % male) with no baseline CSD, underwent CoreValve (n = 72) and Sapien valve (n = 96) implantation. Aortic and MAC calcium score was calculated from non-contrast ECG-gated chest CT scan using Agatston method. Multiple logistic regression was used to analyze the predictive value of each calcium location to predict a new CSD after adjustment for other clinical predictors such as age, gender, diabetes, renal failure, prior myocardial infarction, prior coronary bypass or type of implanted valve. P value < 0.1 was considered as statistically significant.

Results:
Seventy five patients developed persistent or transient CSD (46 had LBBB, 21 had complete AV block and 8 had both). Multiple logistic regression analysis showed infero-posterior MAC (OR = 3.0; p = 0.003), right coronary cusp calcium (OR = 2.2; p = 0.03) and antero-septal MAC (OR = 1.9; p = 0.058) were independent significant predictors of new CSD after adjustment for clinical predictors, while left coronary cusp (OR = 0.8; p = 0.4) and non-coronary cusp (OR = 0.5; p = 0.6) were not. The clinical co-founders were not associated with new CSD.

Conclusions:
Either MAC or right coronary cusp calcium should be considered as a risk marker for new CSD after TAVI.