Response to letter regarding article, "Clinical impact of persistent left bundle-branch block after transcatheter aortic valve implantation with CoreValve revalving system".

BACKGROUND Conduction disturbances are relatively common after transcatheter aortic valve implantation. Previous data demonstrated an adverse impact of persistent left bundle-branch block (LBBB) after surgical aortic valve replacement. It is unclear whether new-onset LBBB may also impact the prognosis of patients after transcatheter aortic valve implantation. METHODS AND RESULTS Among 1060 patients treated with a CoreValve Revalving System transcatheter aortic valve implantation between October 2007 and April 2011 in high-volume centers in Italy, we analyzed those without LBBB or pacemaker at admission (879 patients [82.9%]). We further excluded those who underwent permanent pacemaker implantation within 48 hours after the procedure (61 patients [7%]), for a final study population of 818 patients. Among them, 224 patients (group A; 27.4%) developed a persistent LBBB and the remaining 594 (group B; 72.6%) did not. Clinical characteristics were similar between groups. A low implantation was significantly more frequent in group A (15% versus 9.8%, P=0.02). No patients were censored before 1 year (median follow-up period 438 days, interquartile range 174-798 days). Survival analyses and inherent log-rank tests showed that LBBB was not associated with higher all-cause mortality, cardiac mortality, or hospitalization for heart failure at 30 days or 1 year. At 30 days, but not at 1 year, group A had a significantly higher rate of pacemaker implantation. CONCLUSIONS In this registry of high-volume centers, persistent LBBB after CoreValve Revalving System transcatheter aortic valve implantation showed no effect on hard end points. On the other hand, LBBB was associated with a higher short-term rate of pacemaker implantation.