AATS.16: Investigational aortic valve replacement system is safe and effective at 1 year

After one year, 96 percent of patients with severe aortic stenosis who were implanted with the investigational Intuity aortic valve replacement system had survived, according to a prospective, nonrandomized, multicenter trial.

Lead researcher Randolph Chitwood, MD, founder of the East Carolina Heart Institute of East Carolina University, presented the results on May 16 during a plenary session at the American Association for Thoracic Surgery annual meeting in Baltimore.

Chitwood said that previous trials showed transcatheter aortic valve replacement (TAVR) was safe, secure and reproducible. However, he added that the long-term durability of TAVR has not been established.

Edwards Lifesciences developed the Intuity valve to combine the ease of functionality of a TAVR sutureless valve with the durability of the company’s Perimount Magna Ease valve, according to Chitwood. The FDA has not yet approved the Intuity valve.

“We’ve leveraged the technology learned from balloon stents such as the Sapien valve and married them together so that you have a rapid deployment surgical valve,” Chitwood told Cardiovascular Business. “Rather than sewing this valve in and taking the time to do this, you can balloon expand this and reduce cardiopulmonary bypass time as well as time the heart stops.”

The TRANSFORM trial enrolled 839 low-risk patients at 29 medical centers in the U.S. beginning on Sept. 26, 2012. Of the patients, 109 received the first-generation Intuity valve and 730 received the Intuity Elite valve.

Edwards Lifesciences sponsored the trial.

At baseline, the mean age of patients was 73.5 years old, while 52.2 percent had New York Heart Association (NYHA) Class II heart failure and 30.5 percent had NYHA Class III heart failure. The mean Society of Thoracic Surgeons risk score was 2.5, which Chitwood said meant they were low-risk patients.

“These were the standard aortic valve replacements that you see on a daily basis,” Chitwood said. “The notion was rather than actually cutting the valve out and putting stitches in there and having to put stitches through the valve and then lowering and placing and tying all these knots, it was to cut the old valve out and then put this new valve in and balloon expand it so that you didn’t have to tie knots and put sutures in.”

Of the patients, 59 percent underwent a full sternotomy, 33 percent underwent a mini upper sternotomy and 8 percent underwent a right anterior thoracotomy. Chitwood said the operations were minimally invasive.

Further, 32.8 percent of patients received a 23 mm valve, 29.2 percent received a 25 mm valve, 20.5 percent received a 21 mm valve, 11.7 percent received a 27 mm valve and 5.8 percent received a 19 mm valve. In addition, 62 percent of patients had an isolated aortic valve replacement as their index procedure, while 25 percent underwent aortic valve replacement and CABG.

The Intuity valve reduced the cross clamp times and cardiopulmonary bypass times, according to Chitwood.

The all-cause mortality was 0.8 percent at less than 30 days and 3.0 percent at greater than 30 days. Meanwhile, the rates of thromboembolism (defined as stroke or transient ischemic attack) were 3.5 percent and 2.6 percent, respectively. The major bleeding rates were 1.3 percent and 2.5 percent, respectively.

Two patients underwent a reoperation at less than 30 days and seven patients had a reoperation at greater than 30 days, while one patient and four patients, respectively, had valve explantations.

“You’ll be able to place these valves in younger patients with the knowledge that you’ll get the same results longstanding that you did if you used a pericardial, Perimount Magna Ease valve as a sew-in surgical valve,” Chitwood said. “There are a few exclusionary criteria, but for the standard number of patients that come in with aortic stenosis, you should be able to put this valve in.”

In addition, 14.4 percent of patients had a permanent pacemaker implantation (PPI) at less than 30 days and 2.2 percent had a PPI at more than 30 days.

A retrospective analysis found the following factors predicted whether patients would undergo PPI: a persistent right bundle branch block, atrial fibrillation, atrioventricular block and pulmonary hypertension. Approximately 45 percent of the PPI patients had a right bundle branch block and approximately 20 percent had an atrioventricular block.

Of the PPI group, 33 percent had their pacemaker implanted within the first three days following surgery, 42 percent had the implantation from days four to six, 13 percent had the implantation from days seven to 10 and 12 percent had the implantation beyond 10 days.

Chitwood said the rate of new pacemakers was higher than expected.

“We believe this was influenced by factors other than the valve, including patient characteristics and hospital-specific timing,” he said. “This requires further study.”