(RxWiki News) Newer models of devices aren't always better. This is especially true when it's a device that will help a weakened heart. Two studies from the Henry Ford Hospital in Detroit show that the older model of a commonly implanted heart device is safer.
That newer model -- the Heartmate II -- is a left ventricular assist device that features a continuous-flow mechanical pump connected to the patient's heart that takes over the pumping of a weakened heart's left ventricle.
"Consider the pros and cons of each if you need an implanted heart device."
Researchers said that though the Heartmate II was linked to more instances of bleeding in the skull and gastrointestinal track, there is no increased fatality risk. The research was presented June 11 at the annual conference of the American Society of Artificial Internal Organs in Washington, D.C.
Between March 2006 and May 2010, 64 patients with chronic heart failure underwent implantation of a HeartMate II as a bridge to transplant or as permanent therapy for those ineligible for transplants.
Gastrointestinal bleeding was nearly 22 percent for those who received the device while 8 percent experienced adverse neurological events. Many of those who experienced the latter were older patients with a higher incidence of chronic renal insufficiency and higher International Normalized Ratios, a lab test that measures the time it takes for blood to clot, and compares it to an average at the time of the event. The higher the result, the longer it takes blood to clot.
There were no reported complications due to blood clots in those with gastrointestinal bleeding, but for patients with adverse neurological events, there were four intracranial hemorrhages and one thromboembolic stroke.
The HeartMate II is smaller with fewer moving parts than the previous model, the HeartMate I XVE. It also requires less invasive surgery. The smaller size makes it available to a larger number of advanced-stage heart failure patients, and the continuous-flow pump lasts longer than the pulsing pumps before replacement is needed. The device, which can cover the full output of a healthy heart, is predicted to greatly improve the lives of patients.
Usage of such pumps has increased in the United States, where heart failure affects five million people, but less than 3,000 organs available each year worldwide. Last year 2,500 Americans were implanted with the device.