Original title: Patients Without Prolonged QRS After TAVI with CoreValve Device do not Experience High-Degree Atrio-Ventricular Block. Reference: Gauthier Mouillet et al. Catheterization and Cardiovascular Interventions 81:882–887 (2013).

High degree atrioventricular block (AVB) in the context of transcatheter aortic valve implantation (TAVI) has been reported with variable incidence (3-45%) depending on the population characteristics and the kind of prosthesis. This event happens immediately after TAVI only in 30% of cases, most of BAV being delayed within 7 days after implantation. The study aimed at prospectively identifying post TAVI delayed AVB predictors requiring permanent pacemaker (PP). 

104 TAVI patients were analyzed at one center between 2007 and 2011, with the CoreValve ReValving system (Medtronic, Northridge, CA). 14 patients that were not free from PP before TAVI indication and 11 patients that presented AVB immediately after TAVI were excluded; 79 patients made the final analysis. After implantation, 21 patients exhibited delayed high grade AVB (27%): 17 (80%) in the first week, 3 within 30 days and only one within 12 months. There were no significant differences in clinical baseline characteristics or ECG between those that required PP and those who did not.

Patients that developed delayed high grade AVB after TAVI presented wider QRS duration, greater prevalence of left branch block and deeper implantation; however, QRS duration immediately after TAVI was the sole independent predictor of delayed high degree AVB when performing a multivariable analysis. QRS width as predictor of delayed AVB and the resulting need of a PP had a 0.76 ROC area under the curve (p<0.001; 95% IC, 0.65-0.85) with best cut off at 148 msec, 64% sensitivity and 73% specificity. However, if cut off was lowered to 128 msec, we could achieve 100% sensitivity to predict the need of a PP, resigning some specificity. After a mean follow-up of 10 ± 8 months, patients with post-TAVI QRS ≤128 msec did not require a PP.

Conclusion: 

High degree atrioventricular block after TAVI generally requires a PP. QRS duration immediately after implantation was the best predictor of this event. Patients that presented post TAVI QRS ≤128 msec have no risk of high degree AVB block.

Editorial Comment: 

This precise cut off is relevant to the management of this patients given that a QRS ≤128 msec is not a safe indicator for transitory pacemaker early removal or for hospital discharge. On the other hand, greater duration QRS invites us to be cautious and wait longer to discharge patients, despite the fact that the patient may present optimal clinical conditions. 

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