By OMAR FORD
Medical Device Daily Staff Writer
Daily monitoring of pulmonary artery pressures with an implantable wireless sensor in patients with heart failure led to a 39% reduction in heart-failure-related hospitalizations, according to results from the CHAMPION randomized control trial. Trial results, which evaluated CardioMEMS' (Atlanta) heart failure patient measurement system, were published in the Feb. 9 edition of the Lancet.
The CHAMPION trial enrolled 550 patients at 64 heart centers in the U.S. and was led by William Abraham, MD, at the Ohio State University Medical Center (Columbus, Ohio) and Philip Adamson, MD, at the Oklahoma Heart Hospital (Oklahoma City). It evaluated the safety and effectiveness of CardioMEMS' device in New York Heart Association Class III (NYHA Class III) heart failure patients. NYHA Class III patients represent nearly 30% of the more than six million heart failure patients in the U.S. and account for nearly half of all heart failure hospitalizations.
"The results from the CHAMPION study are very significant and provide a valuable new tool in the battle against heart failure. Pulmonary artery pressure monitoring is the first major device breakthrough in heart failure since CRT therapy," Abraham said.
A major cause for hospitalization in heart failure patients is the build up of fluid pressure in the lungs that eventually causes the fluid to leak into the lung, study researchers said. But the firm's device can monitor this build up and allow the physician to adjust the patient's medication to bring the pressure levels down and keep the patient out of the hospital.
The technology almost serves as a preemptive strike before conditions in a patient deteriorate further, according to CardioMEMS founder/CEO Jay Yadav, MD.
"Think of it this way. You don't really care about one blood pressure reading, per se, but you do care about several readings, and if you can get those measurements down over time you can possibly [reduce the chances of an adverse event]," Yadav told Medical Device Daily. "The CardioMEMS heart failure patient measurement system really is a tool. It's a way to get new information about the patient."
Patients in the trial had the CardioMEMS heart failure sensor permanently implanted in the pulmonary artery using a catheter-based technique. All patients took daily pulmonary artery pressure readings from home that were transmitted to CardioMEMS' secure patient database. For patients in the treatment group only, healthcare providers were provided access to the pressure readings which were used in the treatment of their heart failure condition. For control group patients, healthcare providers were denied access to the pressure readings and they continued to receive standard care.
Results also show that within six months, there had been 83 hospitalizations related to heart failure in the active treatment group, compared with 120 in the control group (HR 0.70, 95% CI 0.60 to 0.84, P<0.0001).
The length of hospital stay was shorter in the treatment group (2.2 days vs. 3.8 days, P=0.02), and the number of changes to drug treatment was significantly higher (9. 1 per patient vs. 3.8 per patient, P<0.0001).
Moreover, unlike other management approaches that typically are useful only in patients whose systolic function is decreased, this treatment monitoring system also was associated with better outcomes in patients with preserved systolic function.
For patients in the active treatment group, the average quality-adjusted life expectancy was 2.506 quality adjusted life years (QALYs), with a cost of $68,919.
Among controls, the quality-adjusted life expectancy was 2.200 QALYs, and the cost was $64,637.
"Thus, the incremental cost-effectiveness ratio of integrating [the wireless implantable hemodynamic monitoring system] into standard of care for management of the heart is estimated to be $13,979 per QALY gained," the researchers observed.
While the study results are mostly favorable, Henry Krum, MD of Monash University (Melbourne, Australia), in an accompanying editorial, which was also mostly favorable, pointed out that the use of the monitor could be associated with a risk of excessive diuresis and vasodilation, and that little information was provided on adverse events such as hypotension that could have been related to changes in drug therapy.
"I think Dr. Krum was confusing the risk/ benefit of right heart catherization to the [risk/ benefit] of the CardioMEMS heart failure patient measurement system," Yadav told MDD.
Yadav, explaining his statement further said that there was the same risk for both right heart catherization and the device, but the benefit differed. For right heart catherization the benefit is limited, while the device's benefit would last forever, he said.
Krum also wrote "in terms of insertion of this device becoming a widespread or routine procedure, we are still some ways off. We are only at the beginning of this revolution in patient monitoring."
Larry Biegelsen, an analyst with Wells Fargo (New York) also commented on Krum's editorial in research notes discussing the implications of the CHAMPION study.
"The accompanying editorial is generally favorable, however, it does raise a few minor issues with the study," Bieglsen writes. "The editorial states that the key issue is how rapid the uptake of this new device might be."
Biegelsen went on to say that most of the online results were similar to data presented at a recent St. Jude (St. Paul, Minnesota) investors meeting. Last fall, St. Jude Medical invested $60 million in CardioMEMS in exchange for a 19% equity ownership interest and an exclusive option to acquire the remaining 81% of CardioMEMS for an additional $375 million during a period that extends through the completion of certain commercialization milestones (Medical Device Daily, Sept. 8, 2010).
"The data in the Lancet are in-line with the data that's already been presented at medical meetings except for a few items," Biegelsen said. "To the best of our knowledge, the cost-effectiveness data included in the paper was new. This data showed that the incremental cost of integrating the CardioMEMS device into standard of care for the management of Class III heart failure was a very favorable $13,979 per Quality Adjusted Life Year (QALY) gained. Generally, a figure below $50,000 is considered cost-effective."
Yadav told MDD that there will be even more information about the cost effectiveness of the device in the future.
"We did do a cost effectiveness study and that will be released sometime this year. "But from the initial analysis that has already been released, it shows that this [product] is going to be quite cost effective [more so] than other devices."
Omar Ford, 404-262-5546;
Published February 11, 2011