How St. Jude Is Buying More Than Just a Heart Failure Device

There is more than meets the eye when it comes to CardioMEMS and its heart failure monitoring device that St. Jude Medical recently acquired for $375 million.

Surgeons implant the smaller-than-a-dime device in a heart failure patient's pulmonary artery during a minimally invasive procedure. Resulting at-home PA pressure readings from the device provide an early warning to doctors that the patient's condition is worsening--and hopefully lead to steps that prevent a hospital readmission.

And yet it is the way that the CardioMEMS HF system provides the readings that make it something that CardioMEMS' founder and CEO Jay Yadav, MD, describes as a "foundational technology."

Yadav claims that the CardioMEMS HF System includes the first FDA-approved implanted device that is a pressure-reading silicon chip, hermetically sealed in glass using a laser. There are no batteries or leads--wires stretching from the pulse generator to the heart that have proved problematic for pacemakers and other implanted devices.

The accompanying plug-and-play transmitter is about the size of an old-school Wi-Fi box, and sends a radio signal that both powers the implant and gets a pressure reading from the chip's circuitry. In order to maintain consistency in readings, doctors instruct patients to lie on a device-reading pillow as soon as they wake up for the day at home. They then simply press a single button on a remote control to take a daily reading that is transmitted to the health provider, either through the patient's home Wi-Fi or through a cell phone network.

The set-up--a radio wave-activated chip that can take pressure readings through the thin layer of glass on one side of the encasement--took years to fine-tune and develop. And Yadav thinks it could be used in other parts of the body to take useful pressure readings.

Implanted chips, for example, might catch increased intercranial pressures, orthopedic stresses, and portal hypertension related to liver disease, Yadav says.

Peter Eckman, MD, an assistant professor specializing in heart failure at the University of Minnesota, agrees that the CardioMEMS device could be a "more sophisticated tool" to monitor patients with heart failure--and that there could be other uses down the road for the technology.

"One area that would obviously be of interest would be to use it in other vascular beds. Let's say you have an aortic dissection, and one of the key treatments for that it to really take control of blood pressure. Having an intravascular way to monitor blood pressure on an ongoing basis--it could potentially be a gold-standard blood pressure measurement for people," Eckman says. (Eckman says he hasn't received any money from CardioMEMS.)

And if nanosensors inside the human body ever become a reality, Yadav suspects they might be super-tiny version of the technology CardioMEMS has developed.

Others, in fact, are also active in the space. For example, Woodbridge, IL-based Endotronix says it has licensed NASA patents for ultra miniature wireless sensor designs, and has developed its own implantable PA pressure monitoring device, though the system is not yet FDA-approved.

The CardioMEMS HF System would have not been possible without the advances in microprocessors and cell phone communications over the past 10 years, according to Yadav. In fact, it was such advances that spurred Yadav to turn to radio-activated, implanted chips, versus other routes for taking daily PA pressures, such as at-home ultrasound.

But is it an end-all-be-all?

The device has faced some criticism in that it involves large pieces of equipment sitting around a heart failure patient's home, and that implanting a device inside an artery is a pretty expensive way to track heart failure. (A spokeswoman for CardioMEMS did not disclose how much the system costs.)

"People could claim this is an expensive scale, but I think this is somewhat disingenuous. ... Weight alone is not the most important factor," Eckman says. Besides reducing hospital readmissions, Eckman suspects the CardioMEMS HF System could hopefully make doctors more judicious in the way they prescribe diuretics to heart failure patients, reducing incidents of kidney failure in the process.

For his part, Yadav acknowledges the home setup could have been smaller, but says the initial goal was simplicity of use--something that is especially important with elderly patients, who are most likely to suffer from heart failure.

Yadav says the CardioMEMS HF System's expense is worth it because no other methods--whether they involve health professionals making daily phone check-ins or daily weight checks--have proved effective in reducing hospital readmissions, an important goal for U.S. health providers under the Affordable Care Act.

David Albert, MD, founder and chief medical officer at smartphone-based ECG company AliveCor, is not sure whether that will be enough to promote use of the CardioMEMS HF System.

"The FDA approval was based on costs of readmissions. This is the device of the day, but I'm confident it will evolve, and new competitors will arise. ... CardioMEMS is expensive, but it monitors filling pressures. Now we need to see how well it works in real world use," Albert says.

Wilson Tang, MD, heart failure research director at the Cleveland Clinic, assisted Yadav with some of the early work on the device when Yadav was at the Cleveland Clinic, but did not receive any compensation or participate in the clinical trials. He is hopeful over the device's potential, but also says time will tell whether the CardioMEMS device is truly effective.

"This is not just a procedure but an enabling process that helps with the potential benefits of heart failure disease management," Tang says.

Chris Newmarker is senior editor of MPMN and Qmed. Follow him on Twitter at @newmarker.