Purpose: To study the clinical outcome of CRT in patients (pts) receiving a bipolar LV lead with a small side helix for active fixation as compared to a quadripolar LV lead with passive fixation.
Methods: Sixty two consecutive pts (mean age 72 ±11 years; 27% females) scheduled for CRT device implantation were randomly assigned to the active fixation bipolar LV lead (n=31) or to the quadripolar LV lead (n=31). The QRS duration was 165±19 ms and 162±18 ms (p=ns) in the active fixation group and the quadripolar group, respectively. The NYHA functional classes of the pts. were class II (n=22), class III (n=37), and class IV (n=3). The LV lead was targeted to the basal segment in a vein concordant to the LV segment with latest mechanical contraction decided by preoperative radial strain echocardiography.
Results (table): The reverse remodeling responder rate at follow up (FU), defined as LV end-systolic volume reduction >15% was high, but not significantly different in the two pt groups. From baseline to 6 months FU the LV ejection fraction improved in both groups, more in the quadripolar group, but at 12 months FU there was no significant difference. The occurrence of phrenic nerve stimulation was 19% in the active fixation group versus 10% the quadripolar group (p=ns), and was resolved in all cases by reprogramming the device.
Conclusions: The improvement of clinical outcome was significant from baseline to 6 months FU, persistant at 12months, and not statistical different between the active fixation group and the quadripolar group of pts.