New, Old CoreValve Iterations Showing Reductions in Pacemaker Need, Paravalvular Leak


PARIS, France—The evolution of self-expanding TAVR devices has enabled researchers to improve outcomes across a wide range of patients. Two studies presented May 20, 2015, at EuroPCR explore results using both an old and new valves from the same manufacturer.

Optimal Practice Improving an Older Device

For the CoreValve ADVANCE II Study, Georg Nickenig, MD, PhD, of Rheinische Friedrich-Wilhelms-Universität Bonn (Bonn, Germany), and colleagues looked at 200 high-risk patients (average age 80.2 years; 47.5% men) with aortic stenosis from 9 European centers who underwent the procedure with the CoreValve device (Medtronic). Mean baseline STS score was 7.2.

Next Step:  New, Old CoreValve Iterations Showing Reductions in Pacemaker Need, Paravalvular Leak

At 1 month, the rate of permanent pacemaker implantation (primary endpoint) was 13.3%—including 6.3% with class III indications, 17.8% with class I/II indications, and 24.1% in patients with known implantation depth. Among patients with 6 mm or greater implant depths (n = 83), 13.3% required pacemakers with class I/II indications and 2.4% required them with class III indications.

At 6 months, the overall pacemaker rate was 14.5%—including 6.8% with class III indications, 18.9% with class I/II indications, and 25.7% in patients with known implantation depth.

Intrinsic rhythm was found in 32% of pacemaker patients at 7 days and in 48% at 6 months (P = .206). Additionally, paired data showed that the amount of time ventricles were paced during the follow-up period decreased from day 7 to 6 months (P = .03). Because of these numbers, “you can entertain the notion that half of the patients didn’t really need a pacemaker,” Dr. Nickenig observed. “This seems to be encouraging.”

New onset left bundle branch block (LBBB) resolved over time—with 36.4% of patients with LBBB (without pacemakers) reporting resolution by 6 months.

The safety outcomes were “pretty remarkable,” according to Dr. Nickenig. Cardiovascular mortality was 1.6% at 1 month and 5.3% at 6 months. Two patients had major stroke at 1 month, with 1 additional patient reporting the complication by 6 months. The incidence of major bleeding and major vascular complications at 6 months were 12.4% and 11.9%, respectively. Finally, 1 patient had an MI by 1 month, with 2 additional MIs reported at 6 months.

Paravalvular leak of a greater than mild indication decreased over time (P = .022), with only 4.3% of patients having moderate or severe regurgitation at 6 months. The same pattern was seen with mitral regurgitation (P = .04). Additionally, wall thickness—interventricular septum and LV posterior wall—decreased from baseline to 6 months (P < .01 for both) while the proportion of patients with LVEF ≥ 45% increased over the same period (P = .009).

NYHA class improved over time with 10.5% of patients in class III/IV at 6 months, down from 74.3% at baseline.

Need for Randomization Questioned

These results demonstrate that “if you apply best clinical practices even in an older device, you can really get good results,” Dr. Nickenig concluded.

Panel co-chair A. Pieter Kappetein, MD, of Erasmus University Medical Center (Rotterdam, the Netherlands), asked if a randomized study is really necessary given these results.

“Absolutely,” Dr. Nickenig responded. “We have to accumulate evidence from registries and from post hoc analyses. But ultimately we need a prospective study. Then we are safe to say we can [proceed with treatment of] intermediate risk patients or not.”

Over the long-term, Dr. Kappetein pointed out that paravalvular leak in this study was higher than it was in the most recent Sapien 3 analysis.

“This was a next-generation iteration of a valve,” Dr. Nickenig said, adding that this endpoint has improved since the original CoreValve device given the new adaptive seal, a lower skirt, and the repositioning capabilities. “I would speculate with the next generation Medtronic valve, the paravalvular leak may go down as well,” he added.

Even so, Dr. Kappetein alluded to the fact that not all core labs are the same and that differences in operations may prevent Sapien and CoreValve analyses from being compared head-to-head.

Evolut R Features Improved Design

For the second self-expanding aortic valve study, Ian T. Meredith, MBBS, PhD, of Monash Medical Centre Clayton (Melbourne, Australia), presented outcomes with the CoreValve Evolut R (Medtronic). The new system was designed as a nitinol-reinforced capsule with flare to provide structural support needed to resheath and reposition the valve. The valve itself has redesigned outflow and enhanced sealing to optimize fit.

Sixty extreme or high-risk patients (average age 82.8 years; 66.7% women) with aortic stenosis from 6 centers in Australia, New Zealand, and the United Kingdom were included in the nonrandomized study. About two-thirds underwent TAVR with general anesthesia, with postprocedural balloon dilatation in 21.7%.

VARC-2 device success (primary endpoint) was achieved in 78.6%. This included no procedural mortality and no patient prosthesis mismatch in 83.6%. At 6 months, valve hemodynamics were good, with 1.9 cm2 effective orifice area and 7.6 mm Hg mean gradient at 6 months.

Repositioning was required 22 times in 15 patients (25%) including 10 partial resheaths in 7 patients and 12 full resheaths in 10 patients. No full recaptures were performed. Ultimately, the final mean implant depth was 6.3 mm in the left coronary cusp and 5.9 mm in the noncoronary cusp.

At 6 months, mild or moderate paravalvular regurgitation was observed in 42.6% of patients with no incidence of severe leak. Three patients died by 6 months—2 due to ischemic heart disease and 1 due to stroke. Permanent pacemaker implantation was required in 7 patients by 1 month and in 1 additional patient by 6 months. There were no instances of embolization or migration, endocarditis, coronary obstruction, or valve thrombosis.

Of those who needed a pacemaker, mean implant depth was 8.1 mm compared with 3.3 mm in those without pacemakers (P < .001).

NYHA class improved from baseline to 6 months with 76.3% of patients improving their class by 30 days and 84.9% at 6 months. The majority of patients (88.7%) were classified as NYHA class I/II by 6 months.

“We must remember that there were no lead-in patients and this was the first time use of repositionable technology in CoreValve users. While we got it right most of the time, there were several cases that were still a little [off],” Dr. Meredith concluded, adding that with increased repositioning experience, need for pacemaker can be reduced even further.

“Hopefully large trials can confirm these very promising results,” he added.


Sources:

1. Nickenig G. Six-month performance of a self-expanding valve in a study of best implantation practices: the CoreValve ADVANCE II study. Presented at: EuroPCR; May 20, 2015; Paris, France.
2. Meredith IT. 6-month outcomes following transcatheter aortic valve implantation with a novel repositionable self-expanding bioprosthesis. Presented at: EuroPCR; May 20, 2015; Paris, France.

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Disclosures
  • Dr. Nickenig reports receiving honoraria and research support and participating in clinical trials with multiple pharmaceutical and device companies.
  • Dr. Meredith reports serving as a consultant to Boston Scientific and Medtronic.

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