Slowly, methodically, Christian Nagy, M.D., manipulates the catheter through a half-inch incision in the 85-year-old patient’s upper thigh and into the femoral artery — a relative interstate in comparison to the two lane blacktops of most other vessels. With eyes glued to the video monitor, Nagy maneuvers the sheath, as the catheter is called, toward the failing aortic valve — the toll booth to the pumping chamber that is the heart’s left ventricle. The sheath carries a new valve sewn into a stent — a stainless-steel mesh scaffold — as well as a crimped balloon the diameter of a fountain pen.
Nagy, director of structural heart disease and assistant professor of medicine at the George Washington University School of Medicine and Health Sciences (SMHS), edges the new valve into position. As the heart rate accelerates, he uses a pressure syringe to inflate the balloon and expand the new valve inside the old, forcing it against the walls of the vessel. In a few seconds, the pacemaker is withdrawn and the heart slows to its normal rhythm. Blood pumps out of the heart into the aorta, through the leaflets of the new valve, which prevent it from sloshing back.At the same moment, a temporary pacemaker approaches the heart, preparing a high-octane boost that drives the heart rate from 63 beats per minute to a 180-beat redline. At that pace, the heart is essentially at a standstill, the force of the beating muscle is diminished and less likely to push the new valve out of alignment.
Nagy eyes his colleagues among a 20-member team crowded into the procedure room of the second-floor Cardiac Catheterization Lab (Cath Lab) at George Washington University Hospital (GW Hospital). To a layman observer, it’s a medical miracle. Instead of invasive heart surgery and all that it involves, patients show little more outward evidence of the experience than a half-inch incision on the upper leg, closed by two sutures. It’s the 1966 science-fiction classic Fantastic Voyage come to life; a non-surgical intervention led by a tiny medical team traveling through the body to rescue a patient.
“The fact that we can operate on a patient without invading the body is amazing to me — and I do it!” saysJonathan Reiner, M.D., director of cardiac catheterization and professor of medicine at SMHS. “It’s the Next Big Thing.”
The procedure is called Transcatheter Aortic Valve Replacement, or TAVR, and it is revolutionizing heart repair procedures in the way bypass and stents have done decades before. An estimated 67,500 aortic valve replacements are performed every year in the United States according to the American College of Cardiology. When the valve is narrowed by stenosis-caused calcification, the heart struggles to push blood through, like a garden hose that’s been constricted. The standard therapy is open-heart surgery, when surgeons split the chest and a new valve is sewn into the heart. The surgery requires up to a week in the hospital, weeks of rehab, a slow recovery, and the threat of infection — especially for an elderly patient.
In the early 2000s, French surgeon Alain Cribier conceived of a technique in which the new valve is placed inside a stent and delivered to the aorta through a blood vessel — the femoral artery — that could accommodate a catheter. “This technology,” Reiner explains, “allows us to treat patients who in the past were thought to be untreatable, or thought to be treatable but very high risk, and we can do it in a minimally invasive way.”
“This is like rebuilding a car engine,” adds Reiner, “without opening the hood.”
“The beauty is that you don’t have to cut anything out, you don’t have to open the chest,” says Nagy, the TAVR point man. “For patients, this is a major advance.” If the femoral artery is not adequate, TAVR can also be performed as transapical — through an incision between the ribs and into the tip, or apex, of the heart.
“Who would want surgery if you have a choice?” asks Nagy.
True enough — but TAVR is not available for everyone and the chosen are still relatively few. Although TAVR procedures have been performed routinely in Europe for more than seven years — half of the valve replacement surgeries in Germany last year were by TAVRs, for example — the practice is relatively new in the United States. The U.S. Food and Drug Administration (FDA), which regulates medical procedures in addition to pharmaceuticals and food, approved TAVR in 2011, but only for patients considered ineligible for surgery. The following year, after successful clinical trials, the eligibility pool was deepened to include those eligible for surgery but still considered to be high-risk (i.e. too old, too frail, or with a history of heart surgery).
The next “frontier,” as Reiner puts it, is intermediate-risk patients. Enrollment has been completed in the latest FDA clinical trial and the study is halfway through a two-year process. “Probably in the next year or two we will see another major shift,” Nagy estimates.
Nagy, a boyish-looking, 43-year-old raised in Germany, most recently trained in interventional cardiology at Tufts Medical Center, and came to GW in September 2013, specifically to build a TAVR program. Only about 300 of the 5,000 U.S. hospitals are approved for this procedure and, in the Washington, D.C. area, only GW Hospital, Washington Hospital Center, and Fairfax Inova Hospital are performing TAVRs.
Nagy spent seven months building the GW program, which involved forming a valve team that includes himself; interventional cardiologists Reiner and Ramesh Mazhari, M.D., associate professor of medicine; and cardiothoracic surgeons Farzad Najam, M.D., FACS, and Gregory Trachiotis, M.D., FACS. They are among the 20 clinicians in the procedure room, as well as key members of the group that review each patient’s candidacy for TAVR.
Another vital team member is Physician Assistant Elizabeth Jones, the TAVR coordinator and the point of contact for patients, guiding them through the process and working to align the schedules of busy team members — “like herding cats,” as she puts it. Typically, patients are referred to the team by a cardiologist and then evaluated through a series of tests, including CTA scans, cardiac catheterizations, and transthoracic echocardiograms, among others. The evaluation process may last up to a month, Jones explains, after which the team decides whether or not a person is a good candidate for TAVR.
GW began performing TAVRs in May 2014; by October the team was completing its 13th procedure. Although the valves, made of heart tissue from a cow, cost about $35,000, the two-hour-long procedure is a bargain when compared with traditional heart surgery and its related expenses, such as extended hospitalization. But one of the remaining questions to be answered is the longevity of a TAVR-placed valve versus a surgical one.
“We have to prove the durability of the valve,” explains Nagy. “Until we know more about the longevity of the valve we can’t say this is going to be the gold standard.” Reiner is wildly optimistic. Once it’s approved for low-risk patients, he says, “you could potentially tell the patient that the procedure will be on Tuesday or Wednesday and you can be back at work Monday. Surgery means a week in the hospital, no driving for three weeks, and back to work in a month, maybe.”
Jones says the rewards for her come from seeing patients feeling better and being able to do more with no fatigue or shortness of breath. “As one patient said to me after TAVR: “I feel like my old self again.”