Thursday, July 15, 2010

Vice President Cheney, Heart Failure and Heart Pumps

The news is awash with reports that former Vice President Dick Cheney had a "heart pump" implanted last week as treatment for his congestive heart failure. Although the details are not available, multiple reports consistently state that he has had heart problems through out most of his adult life, sustaining his first heart attack at age 37. He is quoted in the recent release as stating the he was "entering a new phase of the disease when I began to experience increasing congestive heart failure" and it is further stated that he had a 'heart pump' implanted.
Congestive heart failure is a condition in which the heart muscle is severely weakened reducing its ability to adequately pump blood. It is a very common condition and affects almost 5 million people in the U.S. Heart failure is the single most common reason people are admitted to the hospital. Some heart failure statistics:
-4,8000,000 people with heart failure in US, 2% of population in their 50's, 5% in their 60's, and 10% of population over 70
-875,000 hospital admissions every year in US for heart failure (2400/day). Number one admitting diagnosis
-400,000 newly diagnosed cases of heart failure annually in US (1100/day)
-55,000 people in US die every year due to heart failure (139/day)
-66% of heart failure patients die within 5 years of their diagnosis (worse then most cancers)
-2 people died of heart failure while you were reading this blog post.
Obviously there is considerable room for improvements in the treatment of this condition. Common symptoms of heart failure are shortness of breath, initially with significant exertion, but as it progresses this occurs with less activity. In it's more severe extent, New York Heart Association classification 3B or 4, these patients cannot walk undertake normal activities of daily living without having to stop due to shortness of breath. Other symptoms include swelling of the legs, waking up at night short of breath, having to sleep with the head elevated to facilitate breathing, having to urinate multiple times at night, palpitations and generalized fatigue.
The most common causes of heart failure include coronary artery disease, heart valve problems, and viral cardiomyopathy. Treatment includes dealing with the underlying etiology, which may totally alleviate the heart failure, and/or medicines. As heart failure progresses, in situations where the underlying cause was not reversible, it becomes harder to treat and the symptoms interfere with normal daily activities.
Heart Pumps
In severe cases of heart failure, when medications are no longer effective, and a patients symptoms progress to the point of interfering with normal activities of daily living, a heart pump or left ventricular assist device may be recommended. These bits of ingenious technology have progressed significantly in recent years. The HeartMate II system is the most advanced system currently approved by the FDA. Although not confirmed, this is the device VP Cheney has been purported to have received.
The HeartMate II is a continuous flow device, with a single moving part, a propeller, of sorts, that spins at around 10,000 rpms to aid in the emptying of the heart and restoring normal circulation. Since this device moves the blood at a constant, consistent rate, rather then the rhythmic squeezing type of pumping, these patients usually do not have a palpable pulse.
The indications for implantation of a left ventricular assist device, or LVAD, are for bridging to transplantation, or destination therapy. Bridge to transplant is just what it sounds like, maintaining adequate circulation and restoring the ability to resume full activities while awaiting availability of an appropriate donor organ. Destination therapy is for patients who are not candidates for transplantation and the LVAD serves as the permanent treatment for heart failure in these patients.
In recent studies, the HeartMate II has proven to be very reliable, with 2 year patient survival at about 90% and overall complication rates significantly lower than previous generation devices. Additionally most patient are able to resume full activities. A number of the early recipients of this device are now over 5 years out from their initial implant.
Considering almost 5 million heart failure patients and only 2500 LVAD implants in the US, there is room for much improvement in the lives of many people with this remarkable new technology. I wish Mr. Cheney, and all patients in similar circumstances, a speedy recovery and best wishes for a bright and fulfilling future.
See http://www.youtube.com/watch?v=2auyZ54x2uA for an interview with a recent HeartMate II recipient.