A revolutionary heart assist technology investigated for several years at Allegheny General Hospital (AGH) has been approved by the FDA for patients with advanced heart failure who do not qualify for heart transplantation. Called the Thoratec® HeartMate II® Left Ventricular Assist System (LVAS), the device is now available as “destination therapy” – or long-term treatment for those patients.
Approximately six million Americans suffer from congestive heart failure and 600,000 new cases are diagnosed each year, according to the American Heart Association. The prognosis for patients with advanced heart failure is poor, with projected one-year mortality rates exceeding those of other terminal diseases such as AIDs, leukemia, and lung cancer.
Though transplantation offers hope for approximately 2,000 advanced heart failure patients each year, more than 250,000 patients have no viable treatment option and are considered at high risk for repeated hospitalizations, severely diminished quality of life and limited life expectancy.
For the 50,000-100,000 heart failure patients in the U.S. who do not qualify for a heart transplant, due to age or other extenuating circumstances, long-term therapy with HeartMate II may be a life-saving option, said Srinivas Murali, MD, director of AGH’s Division of Cardiovascular Medicine and Medical Director of AGH’s Gerald McGinnis Cardiovascular Institute.
HeartMate II is the first and only continuous flow chronic LVAS to receive FDA approval for both bridge-to-transplantation and destination therapy. AGH participated in the clinical trial of the device and is now one of a select number of advanced cardiac centers in the nation qualified to offer the state-of-the-art therapy on a routine basis.
“This technology is a breakthrough for a large group of patients whose therapeutic options until now have been severely limited. The HeartMate II provides cost-effective, long-term circulatory support in a manner that does not merely keep a person with end stage heart failure alive, but maximizes their quality of life. We are thrilled to have played a role in the development this exciting new treatment alternative,” said Raymond Benza, MD, medical director of AGH’s Advanced Heart Failure, Transplantation, Mechanical Circulatory Support and Pulmonary Hypertension Program
In 2009, AGH performed 36 successful implantations of ventricular assist devices and currently has three patients using the HeartMate II as destination therapy. The hospital is recognized regionally and nationally as a leading center for the treatment of heart failure, offering heart transplantation services as well as access to an array of cutting edge investigational heart assist devices. The mechanical circulatory support program at AGH has Joint Commission accreditation and was one of the first programs in the country to receive this distinction.
According to Stephen Bailey, MD, director of AGH’s Division of Cardiac Surgery and Surgical Director of Cardiac Transplantation and Mechanical Circulatory Support, LVADs take over the pumping ability of a weakened heart’s left ventricle, which pumps oxygen rich blood received from the lungs to the rest of the body.
Heartmate II is a fully portable LVAD that allows patients to remain active and lead a relatively normal life. Uniquely designed to have a much longer functional life than conventional pulsatile devices, HeartMate II is much lighter and quieter than its predecessors. The device is made of smooth titanium and powered by a rotary pumping mechanism with only one moving part.
“The Heartmate II is capable of pumping up to 10 liters of blood per minute, covering the full output of a healthy heart. Its smaller size makes it easier to implant and allows us to use this device in women and small adults. The system’s transcutaneous lines are also much smaller and less prone to complications,” Dr. Bailey said.
Weighing approximately 12 ounces and about the size of a D-cell battery, the HeartMate II connects to the heart via a polyester tube that is bored into the left ventricle. Blood dumps straight from the left ventricle into the pump, where a turbine spinning at 8,700 rpm propels blood through the aorta. The system is powered by a small battery pack the patient wears over his shoulders, which is connected to the internal device via a small catheter line threaded through the skin.
Approved as a bridge-to-transplantation device in 2008, HeartMate II’s recent approval by the FDA for destination therapy followed a successful clinical trial of 200 patients enrolled at 38 centers.
The study was a prospective, randomized clinical trial. Patients, who did not qualify for heart transplantation, were assigned to treatment with HeartMate II LVAS or to treatment with the earlier generation HeartMate® XVE LVAS (control group) on a 2-1 basis, respectively.
The study concluded that treating patients with HeartMate II leads to dramatically improved survival (68 and 58 percent at one and two years), functional capacity (80% restored to and sustained at NYHA Class I or II through two years; doubling in six-minute walk test) and substantial improvement in quality of life
Additional positive results demonstrated with the device included:
• Dramatic improvements in functional capacity and quality life for both bridge-to-transplantation and destination therapy. At baseline, 96 percent of DT trial patients were NYHA Class IV/IIIB. Seventy five percent improved to Class I or II at 3 months and 80 percent were Class I or II at 24 months.
• Significant reduction of adverse events with HeartMate II , including bleeding, infection and stroke.
• Substantial and sustained improvement in the HM II patients’ 6-minute walk test. The number of meters walked at two years more than doubled from baseline. At two years, HeartMate II patients achieved a median 6-minute walk of 372 meters, more than the distance of 4 American football fields. This improvement in 6-minute walk is a 3-fold improvement observed in Class IV patients during a previous study with the earlier generation device.