Wireless Device May Keep Heart Failure Patients Out of Hospital

June 1, 2010— -- Among heart failure patients with moderate to severe disease, six months monitoring with an investigational implantable sensor that measures pulmonary artery pressure was associated with a 30 percent lower risk of ending up in the hospital for heart failure.

Dr. William Abraham of Ohio State University and Dr. Philip Adamson of the Heart Failure Institute at the Oklahoma Heart Institute in Oklahoma City, reported the findings from the phase III trial of a device called the CardioMems Heart Sensor at the Heart Failure Congress in Berlin.

The trial was known as the CardioMEMS Heart Sensor Allows Monitoring of Pressure to Improve Outcomes in NYHA Class III, or CHAMPION for short. Dr. Robert Califf, director of the Duke Translational Medicine Institute in Durham, N.C., said the results of the CHAMPION trial present "a solid basis from a randomized trial to use this technology. This is like the guage in your gas tank -- it will be good for people to know that their fluids are at the right level."

But Califf, who was asked by ABC News and MedPageToday to comment on the trial, cautioned that "taking advantage of this advance will require a highly organized follow-up system with excellent communication."

During the trial, all patients in the study were implanted with the device, but only half had active monitoring with the sensor. In light of the results, however, Abraham said the investigators are now switching all of the patients to active monitoring mode.

The CardioMEMS sensor is a "wireless, battery-less, radiofrequency activated system," Abraham said. The device can be implanted in the right or left pulmonary artery branch and "has an average implant time of seven minutes" after a patient undergoes a common heart procedure known as catheterization.

All patients after the procedure must continue of commence treatment with blood thinners, Adamson said.

The sensor, which is about the size of a paper clip, is activated when the patient places a wand-like device over the implant area or lies on the wand. The wand activates the monitor by radiofrequency, and pulmonary pressure readings are sent to the physician's office. Increases in pulmonary pressures were treated in a number of ways, Adamson said.

While the researchers regarded improvements in rates of hospitalization for heart failure as the primary measure of the device's success, Abraham said in an interview that "all hospitalizations were reduced." He said that was an important consideration since reducing heart failure hospitalizations while increasing hospitalizations for other causes would not yield a net benefit.

Change in pulmonary artery pressures was a secondary indicator of effectiveness, and here, too, the results were impressive.

In an interview with MedPage Today, Abraham called the results of the CHAMPION study a "grand slam home run," and the audience at the Berlin International Congress Center seemed to agree.

Henry Krum of Alfred Hospital in Melbourne, Australia, who served as discussant for the study, predicted that the CHAMPION study would immediately be regarded as a landmark trial, and rather than marking an evolution in heart failure treatment "this may be the start of a revolution in management of heart failure patients."

The primary six month safety endpoint of the trial was freedom from device or system-related complications. There were no pressure sensor failures in the trial and but there were a total of eight device or system related complications, including two that occurred among 25 patients who consented but were never implanted with the device and three in each of the study arms.

Asked about the severity of those complications, Abraham said there were no serious adverse events such as stroke or myocardial infarction, but beyond this he did not elaborate.