IJCS | Volume 32, Nº5, September/October 2019

493 Cedenilla et al. Requirements for permanent pacemaker afterTAVI Int J Cardiovasc Sci. 2019;32(5):492-504 Original Article implantation are: A CoreValve ® (self-expanding) and Sapien ® (balloon-expandable). 11,12-16 Percutaneous implantation has evolved a lot over the past years, but it presents some challenges. Conduction disorders requiring permanent pacemaker implantation are among the main complications of the procedure. TAVI is associated with a greater need for pacemakers compared to surgery, particularly when the CoreValve ® prosthesis is used. 17-24 Inadditionto thegreaterneedforpermanentpacemaker implantation, a higher incidence of intraventricular conduction disorders has been demonstrated, notably left bundle branch block (LBBB) after TAVI. Several authors have shown that the development of LBBB after TAVI is associatedwith a greater need for pacemaker, ventricular dysfunction and increased long-term mortality. 25-27 The objectives of this study are to determine the incidence of new conduction disorders and the need for a permanent pacemaker after TAVI, to identify predictors of the need for a permanent pacemaker, and to conduct an exploratory analysis to describe the long-termmortality of patients who developed conduction disorders. Methodology Retrospective study. The study included all patients undergoing TAVI in a major public cardiology hospital from December 2011 to June 2016. TAVI was recommended for patients with severe AoS considered to be inoperable or at high surgical risk by a Heart Team of clinical cardiologists, interventional surgeons and cardiac surgeons. The decision of surgical risk was obtained by calculating the EuroSCORE I. 28 The decision on the best form of treatment — clinical, surgical or TAVI — was taken by the Heart Team, considering the risk assessed by Euroscore and other variables not considered in the score but increased the surgical risk, such as the presence of porcelain aorta, fragility level, hostile chest and cirrhosis of the liver. The feasibility of TAVI was determined after analysis of tomographic images from aortic measurements, aortic ring diameter, coronary artery height and femoral artery caliber. Some factors involved in planning the procedure, such as the best access route and the type and size of the prosthesis to be implanted, were defined by the surgical and interventional team after analysis of tomographic images. The prostheses used were CoreValve ® from Medtronic, Sapien ® from Edwards and Inovare ® from Braile. The access routes were transfemoral, transapical, transaortic and the subclavian artery. Transfemoral access was the preferred route in the absence of severe iliac or femoral artery disease. The transapical access route was recommended for patients with inadequate vascular access. The prostheses used for transapical access were Sapien ® and Inovare ® . All implants were performed under general anesthesia. Temporary transvenous pacemaker was implanted in all patients before the procedure andmaintained for at least 48 hours. The study was approved by the local research ethics committee and all patients undergoing TAVI signed an informed consent. All data were collected by the first author of this manuscript by reviewing medical records. The electrocardiograms available in the medical records were ordered according to the dates they were taken. These electrocardiograms were divided into 4 groups: Pre-TAVI ECGs, ECGs taken after TAVI but still in the intensive care unit, ECGs after TAVI taken at the ward and ECGs taken at outpatient follow-up. The ECGs were analyzed independently by the author and a second cardiologist. The electrocardiographic reports followed the criteria defined by the Brazilian Guidelines on Electrocardiography. 29 The criterion used to recommend a permanent pacemaker still in the operating room after the TAVI was implanted was the presence of high-grade AVB or intrinsic rhythm of less than 40 beats per minute during inhibition of the temporary pacemaker. Recommendations of a permanent pacemaker while in hospital were determined by a team of clinical cardiologists, electrophysiologists and intensivists, considering the Brazilian and European guidelines for the implantation of artificial cardiac pacing devices. 30,31 Statistical analysis Statistical analysis was performed using SPSS and Microsoft Excel. The dichotomous variables possibly predicting the need for permanent pacemaker implantation during hospital stay were determined by preparing contingency tables and determining the odds ratio. The P value was calculated using Fisher’s exact test. Every association with P < 0.05 was considered significant. The continuous variables of normal distribution that were predictors of the need for permanent pacemaker