Advancements in artificial heart valve therapy have improved patient outcomes over the years. These advancements have reduced the risk of thrombosis, enabled less-invasive surgical techniques, and required less reliance on medication.
Why would someone need an artificial heart valve?
Certain conditions can cause damage to heart valves including advanced high blood pressure, heart failure, aortic atherosclerosis, heart attack-caused scarring, rheumatic fever, infections, etc. Artificial valves are surgically inserted to replace the function of damaged valves.
How did we get where we are today?
Before the highly advanced TAVR procedure — transcatheter aortic valve replacement — was available, many years of study went into improving valve construction and placement. A look at the career of Intermountain Medical Center Heart Institute cardiothoracic surgeon Kent Jones, MD, shows a recent history of enhancements of valve replacements.
Dr. Jones has been the principal or sub- investigator on 15 grant-funded research studies and an author on 50 other studies, his most influential work being in the area of artificial heart valves.
His work has helped develop mechanical and bioprothetic valves and has proven the benefit of the TAVR procedure.
Doctors have implanted mechanical heart valves in patients since the 1950s — though their designs changed and improved every few years since then. The St. Jude mechanical heart valve is the most common artificial valve in use today.
Mechanical valves only need to be placed once and are good to go for the duration of a patient's life, eliminating the need for additional operations. But their downside is they can lead to formation of blood clots, which requires patients to use blood-thinning medications.
Between 1977 and 2007, Dr. Jones placed 1,300 mechanical valves. He also led a study with St. Jude Medical that found Silzone coating on the devices has no benefit on patient outcomes.
As a result, since 2007, doctors almost exclusively use bioprosthetic valves.
These artificial valves come from animal valves or other animal tissue that’s strong and flexible — typically bovine.
Their main advantage over mechanical valves is they don't lead to the formation of blood clots, which means patients aren't required to use blood thinners. But bioprosthetic valves don't last forever. Depending on patients' health, the valves' life span runs from 10–20 years.
Dr. Jones was the principal investigator on studies that confirmed three new St. Jude Medical heart valves enhanced patient outcomes, and one that identified anticoagulation prescription strategies.
- 2002–2007: An observational, prospective evaluation of the St. Jude Medical Toronto Bioprosthesis with BiLinx
- 2003–2009: An observational, prospective evaluation of the St. Jude Medical Epic Valve
- 2008–2011: An observational, prospective evaluation of the Trifecta Valve
- 2007–2009: Anticoagulation strategy with bioprosthetic valves post-operative event registry
In his career, Dr. Jones has placed more than 1,000 bioprosthetic valves.
Transcatheter Aortic Valves (TAVRs)
These valves are also made from bovine tissue, but they have a different construction that allows doctors to insert them via catheter instead of incision. Both mechanical and traditional bioprosthetic valves require incisions, which are a far more invasive method of insertion.
- PARTNER I: Since 2008, Dr. Jones has led the PARTNER trials — Placement of AoRTic TraNscathetER valves. The Partner I trial began when the FDA allowed Dr. Jones as the principal surgical investigator to place TAVRs in inoperable patients only.
- PARTNER II: After the PARTNER I trial proved TAVRs to be beneficial for inoperable patients, the FDA allowed their placement in high- and intermediate-risk patients starting in 2011.
- PARTNER III: Since 2015, the FDA has allowed half of low-risk patients to receive TAVRs, while the other half must receive a bioprosthetic valve inserted via incision.
Dr. Jones's work has helped lead to mainstream acceptance of TAVRs as a highly beneficial procedure for many patients.