Self-Expanding Transcatheter Valve Maintains Advantage Over Surgery at 3 Years in High-Risk Elderly Patients

Three-year follow up from the CoreValve US Pivotal Trial suggest that in elderly, high-risk patients, TAVR with a self-expanding valve provides durable improvements in clinical outcomes relative to surgery as well as improved valve hemodynamics over time. 

“We believe that these findings support the use of self-expanding TAVR as the treatment of choice in patients at increased risk for surgery,” write lead author G. Michael Deeb, MD (University of Michigan Medical Center, Ann Arbor, MI), and colleagues in the Journal of the American College of Cardiology. Deeb presented the findings on April 3 at the American College of Cardiology 2016 Scientific Sessions in Chicago.

For the trial, 797 symptomatic patients (average age, 83.2 years) with severe aortic stenosis who were at increased surgical risk were randomized to TAVR with the CoreValve self-expanding bioprosthesis (Medtronic) or surgical aortic valve replacement (SAVR) at 45 US centers from February 2011 to September 2012. At 1 year, TAVR reduced all-cause mortality (primary endpoint) compared with surgery (14.2% vs 19.1%; P = 0.04 for superiority), with an absolute survival advantage of 4.8%. At 2 years, the absolute survival advantage for TAVR grew to 6.5% compared with surgery (22.2% vs 28.6%; P = 0.04), with a consistent benefit across subgroups.

Sustained Durability

At 3 years, clinical outcomes were available for approximately 92% of patients who were alive in each group. Compared with surgery, TAVR resulted in numerically better survival, although the difference was no longer significant at 3 years. For secondary endpoints, TAVR was associated with a 20.1% relative reduction in the composite of all-cause mortality or stroke at 3 years. TAVR patients also had lower rates of stroke and major adverse cardiovascular and cerebrovascular events (MACCE).

Patients who received TAVR were more than three times as likely as those who underwent SAVR to have vascular complications and twice as likely to require a new permanent pacemaker, while surgical patients had more life-threatening or major bleeding and acute kidney injury. Most events occurred within the first 30 days.

“These findings demonstrate the durability of self-expanding TAVR in the elderly patients enrolled in this study, but longer-term studies will be needed as this therapy is expanded to younger patients,” Deeb and colleagues write.

Commenting on the study for TCTMD, Timothy J. Gardner, MD (Christiana Care Health System, Wilmington, DE), agreed.

“The 3-year results are excellent, and the benefit is being sustained,” he said. “It’s a very good story for all of us to celebrate, and obviously catheter-based aortic valve therapies are not just here to stay, but will probably be expanded over time.”

Residual Regurgitation Trade-off?

A sustained reduction in mean aortic valve gradients also was seen in the TAVR patients compared with the surgery group, although moderate or severe aortic regurgitation was higher with TAVR (6.8% vs 0; P < 0.001). Rates of worsening aortic valve gradients (defined as a > 50% increase from 1 month to 3 years) were comparable between the groups.

Deeb and colleagues speculate that the hemodynamic benefit “likely relates to the lower profile transcatheter bioprothesis with self-expanding nitinol at the level of the annulus compared with surgery and to the supra-annular location of the porcine pericardial valve.” They caution that the potential benefit of improved hemodynamics “needs to be balanced with the potentially negative impact on survival of residual aortic regurgitation after TAVR, which has been associated with suboptimal late clinical outcomes.”

Gardner added that regurgitation, along with durability issues and need for permanent pacemaker, are good examples of things that may become more of an issue if TAVR is offered to younger populations.

Good News for Intermediate-Risk Patients, Too

The CoreValve 3-year results come on the heels of other good news in the TAVR space. On Saturday, results from the PARTNER 2, Cohort A trial showed that death or disabling stroke at 2 years—the trial’s primary endpoint—were not significantly different for intermediate-risk patients randomized to the Sapien XT (Edwards Lifesciences) or SAVR. The following day, 1-year results of the SAPIEN 3 study showed that the third-generation Sapien 3 valve (Edwards Lifesciences) was superior to a historical control group of SAVR-treated patients at intermediate-risk patients for the endpoints of mortality, stroke, and paravalvular leak.

• Deeb GM, Reardon MJ, Chetcuti S, et al. Three-year outcomes in high-risk patients who underwent surgical or transcatheter aortic valve replacement. J Am Coll Cardiol. 2016;Epub ahead of print. 

Disclosures:

• The study was sponsored by Medtronic. 
• Deeb reports serving on an advisory board and as a proctor for Medtronic; as a consultant and research investigator for Edwards Lifesciences; as a consultant and proctor for Terumo; and as a research investigator for Gore Medical. 
• Gardner reports no relevant conflicts of interest. 

Related Stories:

• Survival Benefit of CoreValve in High-Risk Patients Persists at 2 Years
• TAVR With the CoreValve Device Superior to Surgery at 1 Year
• CoreValve Reduces Mortality at 1 Year in Patients at Extreme Surgical Risk