HEART MONTH: Dauerman, Co-investigators Celebrate First Anniversary of UVM/Fletcher Allen TAVR Trial
- By Jennifer Nachbur
When blood leaves the heart, it flows through the aortic valve into the aorta and returns to the body. But if this valve is narrow, or does not fully open, the flow decreases and the heart must work harder, which can lead to chest pain and ultimately, heart failure. Over the past year, interventional cardiologist and University of Vermont Professor of Medicine and Surgery Harry Dauerman, M.D., and colleagues have made great strides in helping patients with severe aortic stenosis who are at high risk to receive surgical valve therapy in the Medtronic CoreValve® U.S. Pivotal Trial.
One of 45 U.S. sites participating in this clinical trial, UVM/Fletcher Allen has treated dozens of critically ill patients with this new investigational Transcatheter Aortic Valve Replacement (TAVR) technology, says Dauerman, who collaborates with Joseph Smoker, M.D., associate professor of surgery, to perform the procedure. The trial aims to determine whether TAVR is a safe and effective treatment option for certain patients with severe aortic stenosis.
The procedure involves attaching an artificial aortic heart valve to a wire frame, which is guided by thin, flexible tube – a catheter – to the heart. When it gets to the appropriate location in the heart, the wire frame expands, allowing the new aortic valve to open and begin to pump blood.
“During our first year of clinical experience and trial participation, the Heart Team has reached a number of significant milestones,” says Dauerman. “First, we anticipate having treated 30 critically ill patients with this new CoreValve® TAVR technology in the context of our cutting-edge clinical research program. This makes us the highest volume TAVR program in Vermont, New Hampshire or Maine, even though we were not the first program to initiate this new approach to these high-risk patients.”
Another advance has been the expansion of this treatment option using a non-femoral arterial access approach. With leadership from Schmoker, a cardiovascular surgeon, the research team is now using a mini-sternotomy approach for selected patients. This method delivers the aortic valve implant percutaneously – through the skin, beneath the sternum – via a small puncture into the ascending aorta.
“We are also offering some patients a fully percutaneous option now,” Dauerman says. “We are able to use less than a one-centimeter incision in the groin area to do the entire procedure, allowing patients to be out of bed, sitting in a chair, as early as four hours after the aortic valve is replaced.”
The procedure has been extended to the most critically ill patients – including those who are on dialysis or have several diseased valves or suffer from a very weakened heart function.
The team anticipates reaching several new milestones in its second year participating in the CoreValve® trial. Dauerman and Schmoker plan to enroll patients who have received prior aortic valve replacements that are failing, which occurs about ten years following the initial bioprosthetic valve replacement surgery. Dauerman believes these TAVR “valve in valve” procedures can help patients in this high-risk group from undergoing a second surgery. Non-high-risk patients will also be invited to enroll, beginning in spring 2013.
“By randomizing patients at intermediate risk for surgical aortic valve replacement to either standard surgery or TAVR, we’ll be able to understand whether or not TAVR should be expanded clinically as a realistic option for many more patients with severe aortic valve disease,” says Dauerman.