TAVR With the CoreValve Device Superior to Surgery at 1 Year

WASHINGTON, DC—Among patients with severe aortic stenosis who are at increased surgical risk, transcatheter aortic valve replacement (TAVR) with a self-expanding bioprosthesis is associated with better survival at 1 year compared with surgery, according to results presented March 29, 2014, at the American College of Cardiology/i2 Scientific Session and simultaneously published in the New England Journal of Medicine.

David H. Adams, MD, of Mount Sinai Medical Center (New York, NY), and colleagues randomized 795 patients with severe aortic stenosis at increased surgical risk to TAVR with the CoreValve self-expanding nitinol bioprosthesis (n = 394; Medtronic, Minneapolis, MN) or surgery (n = 401) at 45 US centers from February 2011 to September 2012. Most TAVR-treated patients (82.8%) underwent iliofemoral procedures.

Ultimately, 747 patients (mean age 83.2 years; 52.7% men) were treated with TAVR (n = 390) or surgery (n = 357). Procedural success was 99.3% for TAVR.

CoreValve Shows Superiority

The rate of all-cause death at 1 year (primary endpoint) was lower with TAVR compared with surgery in the as-treated analysis (14.2% vs 19.1%; P < 0.001 for noninferiority; P = 0.04 for superiority). Similar results were seen in the intention-to-treat analysis (13.9% vs 18.7%; P < 0.001 for noninferiority; P = 0.004 for superiority).

Although he did not present actual numbers for mortality at 2 years, Dr. Adams said, “We are certainly encouraged by the continued separation of these curves after 1 year.”

Among those with successful implantation, the change in the mean aortic  valve gradient from baseline to 1 year for patients treated with TAVR was noninferior to that of surgical patients (-39.04 mm Hg vs -35.42 mm Hg; P < 0.001 for noninferiority). Additionally, the change in effective orifice area from baseline to 1 year was also noninferior in the TAVR group compared with surgery (1.20 cm² vs 0.81 cm²; P < 0.001 for noninferiority).

In hierarchical testing of secondary endpoints, patients treated with TAVR had noninferior changes in NYHA class and Kansas City Cardiomyopathy Questionnaire score compared with surgically treated patients (P < 0.01 for both). However, superiority was not met by TAVR compared with surgery for the rate of MACCE at 30 days or discharge, whichever came later (8.2% vs. 10.9%; P = 0.10).

MACCE was lower with TAVR compared with surgery at 1 year (20.4% vs 27.3%; P = 0.03), although there were no differences between the groups in individual rates of major stroke at 30 days (4.9% vs 6.2%; P = 0.46) or 1 year (8.8% vs 12.6%; P = 0.10).

TAVR came out ahead of surgery with regard to other procedural outcomes at 30 days and 1 year, with the exception of pacemaker implantation rate (table 1).

Table 1. 30-day and 1-year Outcomes

 

There was less paravalvular regurgitation with surgery vs TAVR at discharge, 1 month, and 1 year (P < 0.001 for all). Also, the survival advantage with TAVR was preserved in all subgroups.

Defining Initial Risk Proves Difficult

Although Dr. Adams was not ready to concede that the trial included low-risk patients, he did acknowledge that the “population may have been at lower risk than what was intended.

“We showed that contemporary risk assessment tools including expert opinions and screening committees are not very good at picking patients that had 15% mortality. On the other hand, maybe surgery is really outperforming what we have historically looked at and collected,” he continued, adding that the trial may represent a paradigm shift. “I’m not sure we know set lines any more. We know small, medium, and large, but the risk lines are becoming blurry.”

Valentin Fuster, MD, PhD, of Mount Sinai School of Medicine (New York, NY), said the results were “absolutely fantastic” and not surprising given the results of the PARTNER B trial. However he pointed out that the survival curves interestingly separate earlier than in PARTNER and suggested this may have been due to the difference in catheter and the self-expanding nature of CoreValve.

Anthony N. DeMaria, MD, of the University of California San Diego (La Jolla, CA) agreed, also pointing out the difference in stroke rate between this trial and PARTNER A.

Dr. Adams explained that “the main difference between our 2 trials was the adjudication of stroke afterward. . . .We were prospectively planning on looking at each patient after surgery. . . and the difference may be attributed [to the fact] that we picked up more strokes after surgery because we looked for them.”

‘Paradigm Shift’ in Treatment

David E. Kandzari, MD, of the Piedmont Heart Institute (Atlanta, GA), commented that the study is “a large step forward for the device specifically, and a giant leap forward for TAVR in general.

“Equally important, that’s less quantifiable, is that this is the study that was performed in a different time with a [more sophisticated] evolution and technique,” he continued. “All of our large data sets today represent, so to speak, first-generation technologies. In many ways this perhaps does represent a paradigm shift in the care of these patients with aortic valve disease in a space where TAVR has not penetrated.”

Dr. Adams concluded that, “This new evidence base is going to change how surgeons who are on the fence about [whether to operate or do TAVR on a patient make decisions]. The economic questions and the insurance questions are all going to come up and be solved if the evidence shows a survival benefit with a procedure.”

Study Details

Diabetes was more common in the surgery group compared with the TAVR cohort (45.4% vs 34.9%; P = 0.003). The majority (55.8%) of the patients scored at least a 5 on the Charlson comorbidity index, indicating a severe burden of illness.

 

 

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Source:
Adams DH, Popma JJ, Reardon MJ, et al. Transcatheter aortic-valve replacement with a self-expanding prosthesis. N Engl J Med. 2014;Epub ahead of print.

 

 

 

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