Frequency of conduction disturbances after transcatheter implantation of an Edwards Sapien aortic valve prosthesis

Frequency of cardiac conduction disturbances after balloon aortic valvuloplasty

Disturbances in atrioventricular conduction are well-recognized complications of transcatheter aortic valve replacement. Percutaneous balloon aortic valvuloplasty (BAV) is a requisite step in transcatheter aortic valve replacement; however, the contribution of the BAV to atrioventricular conduction disturbances has not been elucidated. The present analysis was undertaken to ascertain the incidence and type of electrocardiographic changes associated with BAV and to consider the role of BAV in the conduction abnormalities after transcatheter aortic valve replacement. In 271 consecutive patients with symptomatic, severe aortic stenosis undergoing BAV, a standard 12-lead electrocardiogram was obtained before and serially after the procedure. Each was examined by experienced electrocardiographers. The cohort was divided into 2 groups with regard to the post-BAV appearance of conduction disturbances. The clinical and procedural characteristics of patients with these disturbances were compared to those in whom no conduction disturbance appeared. After BAV, 23 patients (8.5%) met the study definition of "new conduction defect": 4 patients (1.5%) required permanent pacemaker implantation for advanced atrioventricular block. New left bundle branch block appeared in 9 (3.3%) and left anterior hemiblock in 7 (2.6%). New right bundle branch block appeared in 2 and left posterior hemiblock in 1. No significant difference was found in the clinical or procedural characteristics. The ratio of the balloon size to the left ventricular outflow tract diameter was 1.21 ± 1.6 in those with new conduction defects and 1.15 ± 0.12 (p = 0.032) in those without. In conclusion, BAV is associated with a low incidence of cardiac conduction disturbances and a requirement for permanent ventricular pacing. The size of the valvuloplasty balloon should be carefully selected to avoid oversizing, which can lead to the development of postprocedure conduction disturbances.

Transcatheter aortic valve replacement: the changing paradigm of aortic stenosis treatment

Aortic stenosis is the most common cause for valvular surgery in the USA. For nearly 50 years, surgical aortic valve replacement has been the standard of care for symptomatic patients; unfortunately, a significant number of patients are not referred to surgery owing to advanced comorbidities and age. Transcatheter aortic valve replacement has emerged as an effective therapy for patients at high risk for surgery. Through device innovations and accumulated experience, the safety and efficacy of the procedure has improved since its inception. Transcatheter valve replacement has been found superior to medical therapy in inoperable patients with aortic stenosis, yet many questions remain as to which patients are appropriate for this exciting and novel therapy.

Evaluation of multislice computed tomography early after transcatheter aortic valve implantation with the Edwards SAPIEN bioprosthesis

Currently, imaging assessment of patients who undergo transcatheter aortic valve implantation is based mainly on echocardiography and angiography, both limited to provide a 3-dimensional evaluation of the prosthesis within the native valve. This study involved 34 patients who underwent multislice computed tomography (MSCT) after transcatheter aortic valve implantation. Prosthesis expansion and circularity, depth of implantation, apposition degree at the ventriculoaortic junction, and positioning in relation to coronary artery ostia were evaluated. Early clinical events such as aortic regurgitation and periprocedural conduction abnormalities were recorded and correlated with multislice computed tomographic findings. MSCT provided comprehensive 3-dimensional assessments of the prostheses in 31 of 34 of patients (91%). Expansion was excellent (mean expansion ratio 100.0 ± 10.4%) and increased significantly from the ventricular side to the aortic side of the prosthesis. Circular deployment was achieved in most patients and increased from the ventricular to the aortic side. Mean implantation depth was -2.4 ± 2.5 mm, associated with a low rate (12%) of permanent pacemaker implantation. Patients with a new conduction abnormalities had the deepest prosthesis implantation, associated with lesser expansion and circularity. Perfect apposition on MSCT was associated with a low rate of significant aortic regurgitation. In conclusion, MSCT is able to provide an accurate 3-dimensional evaluation of prosthesis deployment and positioning after transcatheter aortic valve implantation. Moreover, these anatomic findings correlate with the most frequent early complications (i.e., the occurrence of aortic regurgitation and conduction abnormalities).

The first successful transapical aortic valve implant in Korea

Transcatheter aortic valve implantation is an alternative to open heart surgery in high risk patients with severe aortic stenosis. High mortality and complications related to cardiopulmonary bypass for conventional open heart surgery can be avoided with this new less invasive technique. In case of concomitant severe arterial disease, the transapical approach is recommended rather than transfemoral access. An 80-yr-old man with symptomatic aortic stenosis and who had very high surgical risk factors such as diabetes mellitus, hypertension, a history of stroke, bronchial asthma including poor pulmonary function and hepatocellular carcinoma was treated with a transapical aortic valve replacement. The expected mortality in this patient was 25.4% by Euroscore if we performed the conventional aortic valve surgery. The patient was discharged and was well at the 45 follow-up days. We report the first case of successful transcatheter transapical aortic valve implantation which is available recently in Korea.

Incidence, predictors, and outcome of conduction disorders after transcatheter self-expandable aortic valve implantation

The aims of the present study were to investigate the incidence and characteristics of conduction disorders (CDs) after transcatheter aortic valve implantation (TAVI), to analyze the predictors of permanent pacemaker (PPM) implantation, and to evaluate the outcomes of CDs over time. In particular, we sought to investigate whether the depth of deployment and other technical aspects of valve implantation might predict the need for PPM implantation after TAVI. TAVI has been reported to favor the onset or worsening of CDs often requiring PPM implantation. A total of 70 patients with aortic stenosis due to dystrophic calcification underwent TAVI with third-generation CoreValve Revalving System from May 2007 to April 2009. We collected electrocardiograms at baseline, during TAVI, during hospitalization and at the 1-, 3-, 6-, and 12-month follow-up visits thereafter. The clinical, anatomic, and procedural variables were tested to identify the predictors of PPM implantation. The PPM dependency at follow-up was analyzed. Six patients were excluded from the analysis because of a pre-existing PPM. Of the 64 patients, 32 (50%) had one or more atrioventricular-intraventricular CDs at baseline. TAVI induced a worsening in the CDs in 49 (77%) of the 64 patients, with 25 (39%) requiring in-hospital PPM implantation. On multivariate analysis, the independent predictors of PPM implantation were the depth of the prosthesis implantation (p = 0.039) and the pre-existing right bundle branch block (p = 0.046). A trend in the recovery of the CDs over time was recorded, although 2 patients required PPM implantation 1 month after discharge for late complete atrioventricular block. In conclusion, TAVI often induces or worsens CDs, requiring PPM in more than one third of patients, although a trend in the recovery of CDs during the midterm was recorded. The independent predictors of PPM implantation were the depth of prosthesis implantation and pre-existing right bundle branch block.