Rationale and design of the SPICE study-septal positioning of ventricular ICD electrodes

Detrimental effects of right ventricular apical pacing have prompted the search for alternative pacing sites. Data from pacemaker studies suggest that the mid-septum may be a hemodynamically favorable pacing site within the right ventricle. However, data on the safety of implantable cardioverter defibrillator (ICD) lead placement in this location are limited. The aim of the SPICE study is to ascertain that implantation of a ventricular ICD lead at the mid-septum is not inferior to the traditional apical site in terms of feasibility and safety.

In total, 286 patients with the indication for ICD implantation will be included in the study and stratified in a 1:1 ratio to have the lead placed in the right ventricular apex or the mid-septum. Primary outcome measure of this randomized, prospective study is the event-free survival of lead-related complications at 3 months. The combined end point includes the feasibility to reach the randomized pacing site in combination with the achievement of adequate pacing, sensing, and defibrillation thresholds. Data analysis and sample size calculation are based on a non-inferiority design.

This trial will primarily assess the feasibility, safety, and efficacy of right ventricular ICD lead positioning in the mid-septum compared to the traditional apical position. Documentation of non-inferiority of the novel lead position in terms of applicability and safety will be the prerequisite for potential further trials that may evaluate long-term clinical effects associated with mid-septal lead positions.