CardioMEMS shows real-world success as use expands

DALLAS – Management of outpatients with advanced heart failure using an implanted pulmonary artery pressure monitor continues to show real-world efficacy and safety at least as impressive as in the pivotal trial for the device.

Data from the first waves of patients to receive the CardioMEMS implanted pulmonary artery pressure (PAP) monitor since it got Food and Drug Administration marketing approval in May 2014 also showed steady uptake of this fluid volume management strategy for patients with advanced heart failure, despite Medicare reimbursement issues in some U.S. regions, J. Thomas Heywood, MD, said at the at the annual scientific meeting of the Heart Failure Society of America. He estimated that more than 6,000 U.S. heart failure patients have now had a CardioMEMS PAP monitor implanted.

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Dr. J. Thomas Heywood

“The clinicians using CardioMEMS now have a lot more experience” than they had during the trial, he said in an interview. “They have more experience using the device, they know what treatments to use to lower PAP more effectively, and they are now convinced that patients will benefit from reducing diastolic PAP.”

Dr. Heywood estimated that tens of thousands more U.S. heart failure patients with New York Heart Association class III disease and a recent history of at least one heart failure hospitalization are eligible to receive an implanted PAP monitor, dwarfing the more than 6,000 patients who received a device so far.

The postapproval study

The newest efficacy data come from the first 300 patients enrolled in the CardioMEMS HF System Post Approval Study, a registry of patients receiving an implanted PAP monitor funded by the device’s manufacturer and scheduled to include a total of 1,200 patients. Dr. Heywood said full enrollment was on track for completion by the end of October 2017.

The first 300 patients enrolled in the postapproval study were older than the CHAMPION cohort; they averaged about 69 years of age, compared with about 62 years in CHAMPION, were more often women (38% vs. 28% in CHAMPION), and were more likely to have heart failure with preserved ejection fraction (41% vs. about 22%).

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Dr. Nirav Y. Raval

A similar pattern existed for the 6-month cumulative tally of PAP area under the curve, which showed an average rise of 42 mm Hg/day in the CHAMPION control patients, an average drop of 160 mm Hg/day in the CHAMPION patients managed using their CardioMEMS data, and a drop of 281 mm Hg/day in the 300 postapproval study patients.

“We’re now using the implanted sensor in a broader population of patients, and one wonders whether the effect will be diluted. What we see is at least as good as in the CHAMPION trial. This is just an early snapshot, but it is exciting that we see no erosion of the benefit. It’s a great indication that the correct patients are receiving it,” Dr. Raval said while presenting a poster at the meeting.

Further scrutiny of the same 300 patients showed another feature of the impact of PAP monitoring on patient outcomes: The first 90 days with the PAP monitor in place led to a greater number of tweaks in patient treatment and a steady fall in PAP. During days 91-180, PAP tended to level off, the number of medication adjustments dropped, and heart failure hospitalizations fell even more than in the first 90 days, Joanna M. Joly, MD, reported in a separate poster at the meeting.

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Dr. Joanna M. Joly

The data showed “effective reduction” of PAP during the second half of the study despite fewer medication adjustments. How was that possible? Patients who transmit data on their PAPs undergo “modeling of their behavior” based on the feedback they receive from the device, Dr. Joly suggested. Regular measurement of their PAP and seeing how the number relates to their clinical status helps patients “understand the impact of their nonadherence to diet and their medications.” Another factor could be the growing familiarity clinicians develop over time with PAP fluctuations that individual patients display repeatedly that are usually self-correcting. Also, patients may undergo “hemodynamic remodeling” that results in improved self-correction of minor shifts in fluid volume and vascular tone, she said.

This pattern of a reduced need for interventions after the first 90 days with a PAP implant suggests that many patients managed this way may be able to transition to care largely delivered by local providers, or even play a greater role in their own self-care once their PAP and clinical state stabilizes, Dr. Joly said.

The findings imply that by the end of the first 90 days, “patients accept the device and manage themselves better. It becomes basically a behavioral device” that helps patients better optimize their diet and behavior, Dr. Raval observed.