Speckle Tracking Radial Strain Imaging-guided Lead Placement for Improving Response to CRT in Patients with Ischemic CMP- The Raise CRT Trial

Background: Previous CRT studies suggest a beneficial effect of using speckle tracking radial strain imaging (STRSI) in LV lead (LVL) location.

Objective: This is a prospective randomized multicenter controlled trial to evaluate the benefit of STRSI for guided LVL positioning in CRT compared to location according to implanter`s preference.

Methods: Patients (pts) with ischemic CMP and CRT indication were enrolled in 9 centers in Israel and US. Pts underwent STRSI to identify optimal LVL position from 6 mid ventricular LV segments according to latest activation without scar. Pts underwent 2:1 randomization to guided placement vs control: guided group (gr) implanters were instructed to implant LVL in the STRSI-determined optimal segment, in controls, the LVL was placed per implanter preference. All underwent 6month (M) clinical, echocardiographic (echo) and 1year (Y) clinical assessment to evaluate CRT response. Primary endpoint was reduction in left ventricular end systolic volume (LVESV) at 6M compared with baseline. Secondary endpoints included hospitalizations for heart failure, improvement in additional echo measurements and quality of life score.

Results: 172pts (115guided, 57control) were enrolled with similar baseline characteristics. LVL implantation failed in 10pts (5 guided, 4 control). In the guided gr LVLs were successfully located at the recommended segment in 60% of cases with 1.5+0.84 attempts/pt. In controls 39% of the LVLs were placed in the recommended position. There was no difference between gr`s in primary or secondary endpoints at 6M (>15% reduction in LVESV, >5% improvement in LVEF, >10 points improvement in MLWHF, >10% increase in 6MW or death or HF hospitalizations) or in clinical endpoints at 1Y. In a post hoc analysis comparing pts of both gr`s in whom LVL was at STRSI recommended position (n=79) to those in whom it was not (n=61), there was a trend toward larger reduction in LVESV in pts in whom the recommended position was achieved (p=0.09) with no difference in any other endpoint at 6M and 1y.

Conclusion: In contrast to previous reports, we found that echo-guided implantation of an LVL using STRSI does not improve clinical or echocardiographic results when compared with conventional implantation in pts with ICMP undergoing CRTD implantation.