Valve Trials Validate Better Ways of Fixing a Malfunctioning Heart
Valvular heart disease – where excessively tight or leaky connections between heart chambers gradually wear out the heart – affects up to 10% of older adults and causes more than 120,000 deaths a year worldwide.
But three new trials from research institutions, including Rutgers Health, all involving patients from Robert Wood Johnson University Hospital (RWJUH), an RWJBarnabas Health facility, support the use of less invasive treatments that work for more patients with valvular disease.
All three trials demonstrated that catheter-based procedures threaded through blood vessels can match the long-term results of open-heart surgery in relatively healthy patients and offer life-saving options to people too frail for open-heart surgery.
Their rapid-fire publications also mark a major victory for Mark J. Russo, professor of surgery and chief of cardiac surgery at Rutgers Robert Wood Johnson Medical School, and chief of cardiothoracic surgery at RWJUH.
“Taking part in clinical trials typically helps all your patients,” said Russo, who made RWJUH among the biggest sites for all three trials. “That’s why I’ve worked so hard over the years to participate as much as possible.”
Russo’s successful trial work should help bring more upcoming trials to New Brunswick, ensuring patients with conditions that respond poorly to existing standards of care have the best possible access to experimental procedures that may work better.
It also means other patients will receive new standards of care as soon as trials validate them – and receive them from teams that already have experience providing the new procedures.
A Different Kind of Heart Problem
Russo spends much of his time explaining to patients that aortic stenosis, the most common serious valve disease in older adults, isn’t the same as a heart attack, which occurs after a blockage in one of the arteries that provide nourishing blood to the heart.
“Aortic stenosis is aortic valve disease where calcium deposits in the valve over the years,” said Russo. “It restricts the leaflets from opening, so basically the valve becomes narrowed.”
In a healthy heart, he tells patients, the valve opening is about the size of a half dollar. By the time it shrinks toward the size of a dime, people start to notice fatigue, shortness of breath and chest pain. If the narrowing continues, the heart can fail or stop suddenly.
From the onset of symptoms, he tells patients, the average time to death without treatment takes a few years at most, and often a few months.
Aortic stenosis is one of many types of valvular disease, each one named for which of the heart’s four valves is malfunctioning and whether it is allowing too little blood to flow forward or too much to flow backward.
Catheter Valves Match Surgery in Low-Risk Patients
Trial results in The New England Journal of Medicine reported on 1,000 relatively healthy patients with severe symptomatic aortic stenosis who were randomly assigned to either open heart surgery or a transcatheter aortic valve replacement (TAVR) through an artery in the leg. Researchers found statistically identical results after seven years in death, stroke and rehospitalization related to the procedure, the valve or heart failure: 34.6% in the TAVR group and 37.2% in the surgery group.
Identical outcomes greatly favor catheter procedures because they’re much easier on patients. Open surgery usually requires a chest incision, hours on a heart-lung machine, at least several days in intensive and step-down care and weeks of limited activity while the breastbone heals. TAVR is typically done through a small puncture in the groin. Many patients walk the hallway the same day, leave the hospital in one or two days and are back to normal activities within a couple of weeks.
When more people can safely undergo valve replacement, and do so through a less traumatic procedure, the potential to cut deaths and repeated hospital stays is substantial.
Even before the latest results appeared, the rising sense that TAVR works about as well as open-heart surgery helps explain why valve replacement volume has exploded. Russo noted that before TAVR, the United States saw about 60,000 aortic valve replacements a year. With transcatheter and surgical procedures combined, that number is closer to 200,000, as people who once would have been turned down for surgery receive treatment.
A New Option for a Leaky Aortic Valve
If aortic stenosis is a narrowed valve, aortic regurgitation is its leaky cousin. Blood that should be moving forward into the body falls back through the aortic valve into the heart, which gradually stretches and weakens.
Until recently, open-heart surgery was the only proven procedure for the condition, so many patients too weak for surgery had to accept inferior care with medication alone. Some surgeons tried to use standard TAVR valves designed for calcified aortic stenosis, but these efforts typically failed because there was too little calcium to anchor them in place.
The second of the three new trials, which appeared in The Lancet, tried to fix that by testing a catheter designed specifically for leaky rather than blocked valves in 700 high-risk patients. The new device beat preset performance targets at 30 days, one year and two years. Death from any cause was 7.7% and 13.3% at two years, sharply under the prespecified 25% one-year target.
Moderate or severe leaking through the new valve was rare. Measures of heart size and function improved, and many patients reported less shortness of breath and better quality of life.
“These are really strong results that indicate the device can improve outcomes for most patients,” Russo said.
Fixing the Mitral Valve Without Opening the Chest
The third study, also in The Lancet, moved the catheter approach to the mitral valve, which separates the heart’s main pumping chamber from the left atrium. When the mitral valve leaks badly – a condition known as mitral regurgitation – blood sloshes backward into the lungs, and patients can become severely short of breath. Many are older and too sick for open-heart surgery. Others don’t have the right anatomy for transcatheter edge-to-edge repair, in which doctors clip the valve’s leaflets together.
The trial enrolled 299 patients who were unsuitable for traditional surgery or edge-to-edge repair and provided them with a new transcatheter mitral valve replacement system. The 30-day mortality was 0.7%, compared with an expected 6.6% surgical mortality based on risk scores. At one year, the composite of all-cause death and heart failure hospitalization was 25.2%, well below the 45% performance goal.
Russo called the device design “brilliant but a little bit complicated” and said the complexity of the procedure would probably limit it, at least initially, to academic medical centers such as RWJUH.
Building a Full Toolbox of Valve Options
For Russo, the through line in all three trials isn’t technology for its own sake. It is access.
“In most of these cases, we are looking at patients who are basically poor surgical candidates, so they could not undergo treatment,” he said. “By having less invasive therapies, those patients have options to treat their valve disease that they would probably otherwise die from.”
Russo said he sees the series as a template for how new valve technologies move from desperate cases to everyday practice. Initial TAVR studies focused on very high-risk patients with severe aortic stenosis who couldn’t safely undergo surgery. As results improved, trials moved stepwise into intermediate and low surgical risk groups, until the most recent trial could show that catheter valves and surgical valves were essentially equivalent in carefully selected low-risk patients over seven years.
A similar path may now unfold for dedicated devices in aortic regurgitation and mitral regurgitation.
Russo said his team also has participated in tricuspid valve replacement studies, so that three of the four heart valves that typically fail in adulthood now have catheter-based treatment options.
“Three important heart valves get diseased in adulthood, and we can treat all of those with catheter-based options at this point,” he said.
Russo said RWJUH has enrolled dozens of patients in each of these trials and has been among the highest enrolling sites nationwide, a pattern that has helped make Rutgers Health and RWJBarnabas Health a regular partner in new structural heart studies.
