Advances in medical science often come with unintended, or at least unexpected consequences. The more radical the advance, often the more troubling and dangerous the unexpected consequences. Such is the case with the Impella heart pump.
Heart pumps, also known as ventricular assist devices, are intended to be inserted into the heart and take over the work of the heart in patients, who are undergoing complex heart procedures or who have certain life-threatening conditions, such as cardiogenic shock or heart damage due to a heart attack. The device allows the body to receive good blood flow while at the same time allowing the heart to rest, or at least not work as hard. The Impella pump is one of the most widely used of these devices. It comes in a few different models to address different ways of assisting the heart.
Impella heart pumps were first approved for use by the FDA in 2008. They and similar heart pumps replaced the older intra-aortic balloon pumps, which were used to pump blood through the arteries of very sick patients whose hearts could no longer do the job. The intra-aortic balloon pumps fell out of favor when questions were raised about their effectiveness. Some cardiologists have raised similar concerns about the Impella heart pumps and believe the pumps cause even more bleeding problems that the balloon pumps.
Like most manufacturers, the company that makes the Impella pumps spends a lot of money on promoting the pumps, on payments to cardiologists for consulting work or for speaking, and on grants to hospitals. In the last year for which data was available, payments other than for product promotion, totaled over $6,000,000.
Since its introduction, over 300,000 Impella pumps have been placed. Most of them have since been removed, or the patient died. Patient death is not that surprising given the degree of heart disease in most of the patients in whom the pumps are placed. They usually have a poor life expectancy in the absence of something to help the heart. It is estimated that there are approximately 66,000 Impella pumps currently in use in the United States.
More recently, the Impella pumps have been the subject of an FDA alert about the risks of fatal heart wall tears or vessel damage during its use. An alert of this type is the most serious action the FDA can take for a product that can result in death or serious injury short of removing the product from the market. It is the third such alert for an Impella pump in the last year.
The FDA was critical of the manufacturer for failing to report incidents of death arising out of heart wall tears or blood vessel perforation during placement of the pumps. According to the FDA, the manufacturer should have filed reports with the FDA of the notices of complication it was receiving. This would have alerted the FDA to the problem and allowed it to conduct an investigation to determine if action was necessary to protect the public.
The manufacturer attributes the heart wall tears and vessel perforations to “operator handling.” It has urged cardiologists placing the pumps to use imaging to avoid puncturing delicate heart tissue. Older patients with delicate heart walls and vessels, women, and patients with heart disease are at greater risk of a tear or puncture. Of course, these people constitute a large portion of the patients in whom the devices are intended to be placed.
Among the complaints made by cardiologists about the Impella pumps is that there have not been large, well-controlled studies to compare the risks of the pumps with their benefits. There is a lot of money to be made in selling the pumps and in placing them. The existence of conflicts of interest in the decision to use an Impella pump cannot be discounted. We and the FDA need more and better data.
