New Option for Older Who are At Risk of Bypass/ Open Heart Surgery
Aortic stenosis is the most common form of adult valvular heart disease. Co morbidity burden, as quantified by the Charlson comorbidity index, was greater in patients who were not accepted for surgery. In a multivariate analysis, increasing age, left ventricular dysfunction and neurological dysfunction predicted the decision not to operate. For this reason, it is imperative that more therapeutic options become available for elderly patients with symptomatic, severe aortic valve disease.
A joint study by the department of Cardiology (Drs. Fish and Paniagua), Texas Heart Institute, Houston in 2005 and concluded that in the treatment of valvular disease, the percutaneous route is a new approach that can be expected to benefit many patients in the future. At present, this procedure is limited to terminally ill patients who have severe aortic valve stenosis that is not amenable to surgical valve replacement. With time, further device modifications should allow transcatheter treatment of valvular disease to become a widely used technique.
Aortic valve replacement surgery is typically an open heart procedure that requires the patient to be on a heart-lung machine for up to two hours. The long recovery can pose a risk for a weakened, elderly patient, and the heart-lung machine has been linked to strokes and memory loss. Open-heart surgery, which is done under general anesthesia. The surgery requires a heart-lung machine and an incision in the chest. The doctor uses patches or stitches to close the hole. This is a great advantage for people who have had previous heart surgery where the chest was opened and scars have formed.
Transcatheter implantation of a balloon-expandable stent valve replacement represents an endovascular alternative to conventional open heart surgery without the need for sternotomy, aortotomy, or cardiopulmonary bypass. Another study also reported that aortic valve implantation can successfully be performed via a minimally invasive apical approach without the need for cardiopulmonary bypass. The early results in this initial series are encouraging. This initial experience suggests that the minimally invasive transapical approach is a viable alternative for patients in whom open-heart surgery is not feasible or poses unacceptable risks.
Moreover; while over 50,000 mitral valve surgical procedures are performed annually, open surgery is an undesirable option, especially for high-risk patients. In the United States, as many as 250,000 patients with valvular heart disease suffer from MR and an additional 2 million Americans with other heart diseases experience it to some degree.
Study by Howard C. Herrmann, MD which was published in Journal Watch Cardiology February 7, 2003 made comment that" this dramatic case illustrates the feasibility of percutaneous heart-valve implantation for calcific aortic stenosis. Future refinements in design and insertion technique might allow this approach to become a therapeutic alternative to surgery in selected patients”. The advantages of the new procedure far outweighed the possible risks.
Another joint clinical study at department of Cardiology, Heart Center Siegburg, Siegburg, Germany and also demonstrated that percutaneous aortic valve replacement is a new technology for the treatment of patients with significant aortic valve stenosis with remarkable functional and clinical improvements in the acute and short-term outcome.
Patients who are not indicated for surgical therapy because it was considered too risky; moreover, they were patients at an advanced age. In addition, aortic balloon valvuloplasty, as previously considered, was no longer concerned. In this particular case, a stent carrier with a biological valve was introduced into the aortic orifice, with the stent carrier pushed into the aortic wall using the balloon in orthotopic position. Initial results are said to be most encouraging.
While percutaneous AVR remains a developing technology, it has the potential to benefit many patients who are poor candidates for surgical valve replacement. A transarterial, retrograde approach would seem to be a significant enhancement with respect to delivery and procedural simplicity. While only three centers in the U.S. currently perform this procedure, others are expected to begin using it in 2007. That will lead to clinical trials to ensure the safety and efficacy of percutaneous techniques compared to current clinical standards of care.
According to Stanford University School of Medicine researchers; "Patients with heart disease who undergo coronary angioplasty have an equivalent risk of death and heart attack as patients who undergo coronary bypass surgery”. The analysis is the largest comparison of bypass surgery and angioplasty, two of the most common major medical procedures performed in North America.
Drug-eluting stent therapy and bypass surgery for coronary artery disease have about the same risk for a major cardiac event within 30 days after the procedures, researchers reported at the American Heart Association's 8th Annual Conference on Arteriosclerosis, Thrombosis and Vascular Biology.
For those who are at high-risk of death from heart bypass surgery due to older age, prior open-heart surgery, recent heart attack, or decreased heart function, percutaneous coronary intervention (PCI) angioplasty may be a safe and more cost-effective alternative, according to a study published in Circulation: Journal of the American Heart Association. The older you are, the greater your risk of developing atrial fibrillation. As you age, the electrical and structural properties of the atria can change. This may lead to the breakdown of the normal atrial rhythm.
Percutaneous heart valve therapy has enormous clinical and commercial potential. Consequently, industry is actively developing novel valves for percutaneous therapy. Older, high-risk heart patients with narrowed aortas who typically need open-heart surgery might someday have a new, less invasive option -- an implanted, balloon-expandable aortic valve.
The balloon is inserted percutaneously (through the skin), placed across the problem valve and then inflated, experts said. In a new study, the procedure -- not yet approved by the U.S. Food and Drug Administration -- showed real health benefits for up to two years. The research is to be presented Sunday at the American Heart Association annual meeting in Orlando, Fla.
"The percutaneous balloon expandable aortic valve insertion provides a safe and sustained alternative for high-risk patients with severe aortic stenosis [closure]," said lead researcher Dr. Sanjeevan Pasupati, who was an interventional fellow at St. Paul's Hospital in Vancouver, British Columbia, when the study was conducted.
"In our first 100 high-risk patients, the intra procedural mortality was only 2 percent with minimal morbidity," Pasupati said. "Our long-term survival is promising, with 70 percent and 60 percent at one and two years, respectively. This procedure is here to stay." Other experts stressed caution, however.
"This is a very exciting frontier for us in terms of being able to potentially fix these with percutaneous approach versus putting patients on a heart-lung machine," said Dr. John P. Erwin III, an associate professor of internal medicine at Texas A&M Health Science Center College of Medicine and a cardiologist with Scott & White Hospital in Temple. However, "this is still considered to be a high-risk procedure that is not quite ready for prime time at this point," he said.
According to the American Heart Association, aortic stenosis involves a blockage of the heart's aortic valve. The aorta is the body's main artery. The aortic valve closes over after each heartbeat to prevent blood from flowing back into the heart's left ventricle.
"Patients who have severe aortic stenosis and who may reach the criteria where they're best suited to have heart surgery often are very elderly and have other significant risk factors, so they're at high risk at the time they have open-heart surgery," Erwin explained. "There's a high prevalence of stroke and, in octogenarians, when we do bypass and place a valve, the combined mortality and major morbidity is about 25 percent."
So, physicians have long looked for an alternative to open-heart surgery.For this study, balloon expandable aortic valves (BEAVs) were implanted in 100 patients, average age 83, of which slightly more than half were male. The procedure was successful in 91 (91 percent) of patients. Two percent of the participants died during the procedure. At 30 days after surgery, 15 percent of the participants had died. There was also "significant improvement" in heart function.
"Currently, this is not an alternative to surgery, and we need to await the results of the FDA-approved randomized PARTNER study," said Pasupati, who is now an interventional cardiologist at Waikato Hospital in Hamilton, New Zealand. "The technology has CE Marked approved [indicating conformity with European health and safety requirements] and is currently available in Europe."
"Definitely, it's going to be something to be watched, but that's only the Canadian trial," added Dr. Carlos Ruiz, director of the division of cardiac intervention for constructive heart disease at Lenox Hill Hospital in New York City. "There are the Canadian trial ongoing, the European trial, as well as the U.S. trial."