"Device landing zone" calcification, assessed by MSCT, as a predictive factor for pacemaker implantation after TAVI

After trans-catheter aortic valve implantation (TAVI), the need for postinterventional pacemaker (PM) implantation can occur in as many as 10-50% of cases, but it is not yet clear, how this need can be predicted. The aim of this study was to assess the possible predictive factors of post TAVI PM implantation based on Computed Tomography (CT) measured aortic valve calcification and its distribution.

We prospectively analyzed 81 consecutive symptomatic patients with severe AS scheduled for TAVI using the CoreValve prosthesis (Medtronic, Minneapolis, USA). In all patients, a native and contrast-enhanced multislice cardiac CT was performed preinterventionally, estimating calcification load of the native valve cusps and of the adjacent outflow tract (so called "device landing zone", DLZ) by the Agatston Score (AgS). Objective, computer-evaluated, preprocedural ECG-analysis was performed with regards to pre-existing conduction abnormalities. Transthoracic echocardiography was performed pre and post TAVI.

TAVI was successful in all cases. PM implantation was deemed necessary in altogether 32 patients, out of 67 without a PM pre-TAVI (32/67, 47%). Various parameters were tested as predictors of post TAVI PM in a multivariate logistic regression analysis model. Female sex (P = 0,005) and depressed EF (P = 0,023) showed a significant correlation. PM implantation correlated also to the DLZ calcification, as assessed by CT (P = 0,004). This model leads to an AUC (area under the ROC-receiver operator characteristics-curve) of 0.83.

Calcium amount in the CoreValve DLZ in combination with clinical data could predict the need for post TAVI PM implantation.