Computed tomographic analysis of left ventricular volumes and function after implantation of the Parachute® endoventricular partitioning device

Background Preliminary clinical experience with a percutaneous endoventricular partitioning device (Parachute®, CardioKinetix Inc., Menlo Park, CA, USA) suggests that it ameliorates global LV dysfunction and heart failure symptoms in selected patients who have suffered previous anterior myocardial infarction. Less is known of its effect on regional LV function.

Objective To gain insight into device effect on regional LV function by analysis of cardiac computed tomographic (CT) images obtained before and after device implantation.

Methods Comparative analysis of pre and 6 months post-implantation contrast-enhanced CT images from 6 subjects enrolled in the phase 1 Parachute clinical trials, including regional LV volume and systolic excursion, as well as device motion.

Results After implantation, a significant reduction in volume of the "dynamic" LV compartment (that which was not excluded by the device) was accompanied by a significant reduction in dykinetic motion and a trend toward an improved ejection fraction. Penetration of contrast into the excluded compartment was still present at 6 months, however the apical motion was significantly less diskinetic in 3 subjects and unchanged in the other 3. Overall device surface motion was inward in systole, a significant improvement relative to the overall dyskinetic LV apex pre-implantation. Device motion was spatially heterogeneous, which appeared to be dependent on the motility of the myocardium that anchored its individual splines.

Conclusions Our data suggest that the Parachute device acts as a functional impediment to flow and stretch, effectively depressurizing the apical segment.