New data from REPRISE III indicate that keeping the bottom of the frame at annular level while implanting and targeting a final depth of 2mm below the annulus of the Lotus transcatheter aortic valve implantation (TAVI) device (Boston Scientific) is associated with a lower new pacemaker rate than the conventional approach of implanting the device further below the annulus.
Speaking at PCR London Valves (24–26 September, London, UK), Christopher Meduri (Piedmont Heart Institute and Marcus Heart Valve Center, Atlanta, Georgia) stated that the REPRISE III trial—presented at the 2017 EuroPCR meeting—showed that the Lotus valve was associated with a significantly lower rate of all-cause death, disabling stroke, and paravalvular leak than was CoreValve (Medtronic) in aortic stenosis patients at high surgical risk. However, he added that Lotus was also associated with a significantly higher rate of new pacemaker implantation at 30 days—29.1% vs. 15.8% for CoreValve (p<0.001).
The aim of the subanalysis presented at PCR London Valves was to explore differences in baseline characteristics and in one-year outcomes between patients with prior pacemaker, no pacemaker, and new pacemaker implantation (after either CoreValve or Lotus). Comparing patients with a prior pacemaker and those with no pacemaker/new pacemaker, Meduri and colleagues found that prior pacemaker patients were older, had lower body mass index scores, had higher EuroScores scores, more atrial flutter, more atrial fibrillation, and more reduced left ventricular ejection fraction (<40%). Furthermore, patients with prior pacemaker had significantly higher rates of all-cause mortality or disabling stroke at one year; 19.9% vs. 12% for no pacemaker/new pacemaker (p=0.009).
According to Meduri, patients who received a new pacemaker had more atrial fibrillation and chronic obstructive pulmonary disease (COPD) than those without a pacemaker “but otherwise there were no significant differences” between groups. Unlike the prior pacemaker group, the new pacemaker group were not found to have worse one-year outcomes than those without a pacemaker. However, he commented that there “were small differences” in quality of life between groups—with new pacemaker patients having significantly worse SF-12 physical summary scores (p=0.044 for the comparison). Also, at six months, the incidence of reduced left ventricular ejection fraction was higher in new pacemaker patients (p=0.004 for the comparison).
In a multivariate analysis, medically-treated diabetes, mean depth, moderate or grater COPD and being at extreme surgical risk were all independent predictors of new pacemaker implantation in patients receiving the Lotus valve. For patients receiving CoreValve, the only independent predictor of new pacemaker implantation was mean depth.
In a separate substudy, Meduri and colleagues also reviewed the impact of implantation technique on the new pacemaker rate after TAVI with Lotus. He explained that in REPRISE III, three techniques had been used. “For the first 22 patients, there was the traditional Lotus implant technique—deep initial entry and landing the radioplaque marker mid pigtail. For the second batch of 22 patients, there was deep initial entry but targeting implant depth of the bottom of the frame 3–4mm below the annulus. With the last 33 patients, bottom of the frame at annular level while implanting and targeting a final depth of the bottom of the frame at 2mm below the annulus,” Meduri commented, observing that “it is not just how high you finish, but how you get there” that is relevant when implanting the device.
He added that study was not adequately powered to show significant differences between the techniques but noted that “by modifying the implantation technique, there seemed to be a much lower new pacemaker rate”. The rate of new pacemakers was numerically lower for patients who underwent the second implantation technique compared with those underwent the first implantation technique and was numerically lower for those underwent the third technique compared with both the second technique patients and the first technique patients. “Device iterations and improvements in technique will potentially lower the permanent pacemaker rate,” Meduri concluded.
At present, both fist-generation Lotus device and the second-generation device (Lotus Edge) are off the European market (neither have FDA approval). They were taken off the market because of a problem with the locking mechanism of the delivery system. However, this issue is thought to have been resolved and Boston Scientific plan to put Lotus Edge back on the market by the end of this year.
Meduri told Cardiovascular News: “Moving forward, I expect that the modified implant technique will be standard of care with Lotus patients. I also anticipate with the launch of Lotus Edge, there will be an even further reduction in new pacemaker requirements. New implant technique and Lotus Edge should allow Lotus to achieve similar pacemaker rates as Evolut Pro and Sapien 3.”