Transcatheter Aortic Valve Implantation Without Predilation

Aortic Stenosis, High-risk Patients, Left Ventricular Function Systolic Dysfunction, Transcatheter Aortic Valve Implantation

Aortic stenosis, Transcatheter aortic valve implantation, TAVI, Predilation, Balloon valvuloplasty, BAV, CoreValve

The purpose of this study is to demonstrate that the avoidance of balloon valvuloplasty for predilation of the native aortic valve is associated with a reduction of the composite primary endpoint in TAVI patients with severely impaired left-ventricular ejection fraction (LVEF ≤35%).

Transcatheter aortic valve implantation (TAVI) has evolved as an alternative to surgical aortic valve replacement (SAVR) with now more than 50,000 implantations in patients with symptomatic severe aortic stenosis, who were considered to be at very high or prohibitive operative risk. Before deployment of transcatheter heart valves (THV), current medical practice requires right-ventricular rapid burst pacing (\>180 bpm) with induction of a functional cardiac arrest for up to 30 seconds for balloon aortic valvuloplasty (BAV). This step is thought to be necessary to predilate the native aortic valve and to facilitate an accurate positioning of the THV. However, BAV has been shown to have numerous detrimental effects: i) the functional cardiac arrest induced by rapid pacing for BAV leads to transient coronary, cerebral, and renal ischemia. ii) In patients with impaired left ventricular ejection fraction, prolonged cardiac depression after rapid pacing is observed and may result in hemodynamic failure and systemic inflammatory response syndrome (SIRS), which are both associated with a high peri-procedural mortality. iii) BAV has been identified as a major source of embolization of thrombotic and valvular material and increases the risk for coronary obstruction with subsequent myocardial infarction and stroke. iv) the local trauma in the left-ventricular outflow tract caused by BAV contributes to conduction disturbances with the need for permanent pacemaker implantation after TAVI. A non-randomized pilot study by Grube et al. (JACC Interventions 2011) has recently shown that TAVI without BAV is feasible and safe, since self-expanding THV are able to dilate the stenosed aortic valve through the radial forces of the self-expanding nitinol frame, in which the prosthesis is mounted. According to the mentioned study, omitting BAV allows the delivery of the THV in a controlled fashion without hemodynamic compromise of the patient. Patients with LVEF≤35% will be randomized (like the flip of a coin) to TAVI without BAV (experimental group) or TAVI with BAV for predilation (control group).

Germany