When bioprosthetic valves fail, transcatheter valve-in-valve implantation may be a viable option used to mend aortic, pulmonary, mitral and tricuspid tissue valves, based on a study published in Circulation on April 12.
John G. Webb, MD, of the St. Paul’s Hospital in Vancouver, British Columbia, and colleagues performed transcatheter valve-in-valve implants in 24 high-risk patients whose prior artificial animal-based aortic and mitral bioprosthetic heart valves failed. Bioprosthetic heart valves are often the favored treatment, however, because of their nature to deteriorate and fail, re-operation is often necessary and carries risks, they wrote.
“Transcatheter heart valve (THV) implantation has found rapid acceptance as an alternative to conventional surgical valve replacement for patients with native aortic valve stenosis,” the authors wrote. “THV implantation might also represent an attractive option for patients with failing bioprosthetic valves.”
During the study, 10 procedures were performed to the aortic valve, seven to the mitral valve, six to the pulmonary and one to the tricuspid valve.
For aortic and mitral valve-in-valve procedures, balloon-expandable catheters were used via the transapical or transarterial approach, while pulmonary procedures were performed using percutaneous transvenous access. Small incisions were made between patient’s ribs or through a puncture site in a blood vessel of the leg where the artificial valves were placed inside the old surgical valve and expanded with a balloon-expandable catheter.
Overall, the results showed that 30-day mortality rates were 4.2 percent and device and procedural success rates were 98.6 percent.
While all patients survived the transcatheter procedures, two deaths were reported during the study. One mitral valve patient who was transferred to open-heart surgery suffered a stroke and renal failure and later died, while another mitral valve patient died 45 days after surgery. The study exhibited 91.7 percent patient survival rates.
For patients who underwent valve-in-valve implants to their aortic and pulmonary valves, all implants were successful and all patients remained alive at both 30-day and 83-day and 185-day follow-ups.
Additionally, for those who underwent valve-in-valve implantation to the mitral valve, the first attempt using the transseptal approach proved unsuccessful; however, researchers then used transapical access. “All five subsequent high-risk mitral procedures were transapical, successful, and without mortality,” the authors wrote.
For the one patient who underwent valve-in-valve implantation to the tricuspid, catheter positioning failed, but researchers then used a surgical approach to facilitate coaxial positioning and successfully deployed the device. The patient improved 260 days after follow-up.
"The advantage is that failing surgical valves can be replaced without the need for open-heart surgery,” said Webb.
“Currently available THVs appear to have hemodynamic properties comparable to those of the best surgical bioprostheses,” the authors wrote. “This finding may have important implications with regard to valve replacement in patients at prohibitive risk for conventional surgery,” the authors concluded.
In an accompaning editorial, Blase A. Carabello, MD, of the Baylor College of Medicine in Houston, wrote that the advent of percutaneous device therapy for valvular heart disease (VHD) is one of the most exciting events in cardiology in the last 50 years.”
In addition Carabello asked: “Will we let the genie out of the bottle again as we did with PCI, when some procedures were performed without clear cut indications or even clear cut benefits?”
Carabello suggest that while research on the topic seems promising, the decisions whether or not to perform these VHD procedures should be made under a cardiovascular board where cases are presented and decided on, what he says is done now in the oncology field.
“Let us keep the genie in the bottle this time around and make the field of percutaneous valves one of clinical, ethical and therapeutic envy for the rest of medicine,” concluded Carabello.