PARTNER Registry Documents Strides Made in Transfemoral TAVR

Patients who underwent transfemoral TAVR as part of the nonrandomized continued access registry of the PARTNER trial had lower complication rates at 30 days and lower mortality at 1 year than those enrolled in the randomized trial, according to results of a study published in the November 2014 issue of JACC: Cardiovascular Interventions. The study authors say greater operator experience, device improvements, and better patient selection all likely contributed to the difference.

William F. Fearon, MD, of Stanford University Medical Center (Stanford, CA), and colleagues compared outcomes between 2 groups:

  • Patients who underwent transfemoral TAVR in cohorts A (n = 240) and B (n = 175) of the PARTNER trial at 27 sites between May 2007 and August 2009
  • Patients enrolled in the PARTNER Nonrandomized Continued Access (NRCA) registry at 27 sites between September 2009 and January 2012 (n = 1,023)

While all received the Sapien valve (Edwards Lifesciences), more than 85% of trial participants were treated using the RetroFlex 1 or 2 delivery system (Edwards Lifesciences) and 100% of registry patients received the valve via the newer RetroFlex 3 delivery system.

Registry, Randomized Patients Different

Compared with the trial participants, patients in the registry were older but had lower STS scores and logistic EuroSCOREs. While more registry patients had received a previous balloon aortic valvuloplasty, fewer of them had cerebrovascular disease, PAD, renal disease, or oxygen-dependent COPD compared with trial participants. There were no differences between the groups in aortic valve area, mean gradient, or LVEF.

Additionally, registry patients were less likely to undergo surgical cutdown for arterial access or postdilation after valve deployment and had shorter procedure times (117.6 ± 57.0 min vs 145.1 ± 82.3 min; all P < .0001). The groups had similar rates of moderate or severe paravalvular regurgitation at 30 days, 6 months, and 1 year after TAVR.

At 30 days, there were no differences between registry and randomized patients in all-cause death, cardiac death, stroke, or transient ischemic attack (TIA). However, the registry cohort had lower rates of major vascular complications (8.0% vs 15.7%) and major bleeding (6.8% vs 15.3%; both P < .0001). By 1 year, all-cause death was 27% lower in the registry group, with trends for less cardiac death, stroke or TIA, and major stroke (table 1).

PARTNER Outcomes at 1 Year

According to Dr. Fearon and colleagues, the differences in baseline characteristics between the trial and registry participants argue for “improved patient selection as a result of investigator experience and in part by increased availability of the transapical access approach in the NRCA group.”

Growing experience with TAVR—the mean number of patients treated per site increased from 15 during the PARTNER trial to 38 in the registry cohort—led to shorter procedure times and improved outcomes, the authors say.

Also of interest is the lower rate of valve postdilation in registry compared with randomized patients, with no difference in paravalvular regurgitation, the investigators observe. “This finding may be explained by enhanced operator experience with valve sizing and by the increased availability of the transapical approach, resulting in less need to deploy a 23-mm valve because of femoral or iliac vessel size limitations.” they write.

As for the delivery system, the RetroFlex 3 “may have allowed for more rapid crossing of the native valve and for more precise positioning during deployment of the valve,” they note. “These differences may have affected the time of the procedure and the complication rate.”

Advantage of Experience Clear

In an accompanying editorial, Martyn Thomas, MD, of St Thomas’ Hospital (London, England), writes that it would have been disappointing if the registry results were not better than those of the randomized PARTNER trial.

He adds that the NRCA registry results covering patients who received the first-generation Sapien valve compare favorably with those of European registries involving second- and third-generation devices. Furthermore, he says, it would be interesting to compare the NRCA registry and the surgery arm of PARTNER Cohort A. Though Dr. Thomas cautions that the exercise is only speculative, he points out that the later TAVR experience would represent a 29% reduction in 1-year mortality versus surgical replacement.

It remains unclear from the paper, however, whether the percentages of high-risk and inoperable patients being treated in the registry diverge from those of the randomized trial, Dr. Thomas notes. In PARTNER, 58% of patients were high risk and 42% were inoperable.

Note: Two coauthors are faculty members of the Cardiovascular Research Foundation, which owns and operates TCTMD.

 

 

Sources:

1. Fearon WF, Kodali S, Doshi D, et al. Outcomes after transfemoral transcatheter aortic valve replacement: a comparison of the randomized PARTNER (Placement of AoRTic TraNscathetER Valves) trial with the NRCA (Nonrandomized Continued Access) registry. J Am Coll Cardiol Intv. 2014;7:1245-1251.

2. Thomas M. Outcomes after transfemoral transcatheter aortic valve replacement [editorial]. J Am Coll Cardiol Intv. 2014;7:1252-1253.

Disclosures:

  • Dr. Fearon reports receiving research support from St. Jude Medical and serving on the steering committee for the PARTNER II trial.
  • Dr. Thomas reports serving as a consultant to and an advisory board member of Edwards Lifesciences. 

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