CardioMEMS shows real-world success as use expands

Safety holds steady

Continued real-world use of PAP monitoring has also resulted in new safety insights. During the first 3 years when the CardioMEMS device was on the U.S. market, May 2014–May 2017, the FDA’s adverse event reporting system for devices, the Manufacturer and User Facility Device Experience (MAUDE) received reports on 177 unique adverse events in 155 patients implanted with a PAP monitor, Muthiah Vaduganathan, MD, reported at the meeting. During the same 3-year period, he estimated that at least 5,500 U.S. patients had received a CardioMEMS device, based on data Dr. Vaduganathan obtained from the manufacturer, Abbott. This works out to an adverse event rate of about 2.8%, virtually identical to the rate reported from CHAMPION, noted Dr. Vaduganathan, a cardiologist also at Brigham and Women’s.

^{Mitchel L. Zoler/Frontline Medical News}

Dr. Muthiah Vaduganathan

Analysis of both the 22 deaths as well as the episodes of pulmonary artery injury or hemoptysis showed that the preponderance occurred relatively early after introduction for U.S. use, suggesting that “a learning curve may exist for the most serious complications,” he said. “Improved safety and device durability may result from careful patient selection, increased operator training, and refined technologies.”

Dr. Vaduganathan cautioned that the MAUDE database is limited by its bias toward serious adverse events, selective reporting, and lack of adjudication for the reported events. Concurrently with his report at the meeting, a written version appeared online (JAMA Cardiol. 2017 Sep 18. doi:10.1001/jamacardio.2017.3791).

“The adverse event rate was reassuringly low, well below the accepted threshold for device safety. It bodes favorably for the device,” he said in an interview.

“But with a passive surveillance system like MAUDE, adverse events are likely underreported; we see in MAUDE the most severe adverse events. There is certainly a larger spectrum of more minor events that we are not seeing, but I think these numbers accurately reflect serious events.” A full registry of every U.S. patient who receives the device, similar to what’s in place for U.S. patients who undergo transcatheter aortic valve replacement, would provide a more complete picture of the risks, Dr. Vaduganathan suggested.

He also voiced some surprise about the frequency of pulmonary artery injury, which was not as apparent in the 550 total patients enrolled in CHAMPION. Clinicians who place the PAP monitor are required to first take a training program, but the manufacturer has no mandated minimum number of placements an operator must assist on before launching a new CardioMEMS practice, Dr. Vaduganathan said. Many of the pulmonary artery injuries reported to MAUDE resulted from wire perforations that resulted from loss of wire control, he noted.

Clarifying the optimal CardioMEMS recipients

PAP monitoring for patients with advanced heart failure “is a major advance for certain patients who have historically been very challenging to manage,” especially patients with heart failure with preserved ejection fraction, which has few other treatment options. But “it’s often difficult to know when to pull the trigger” and proceed with placing a PAP monitor in an eligible patient, he said. “Greater experience will help us better understand that,” Dr. Vaduganathan predicted.

Dr. Heywood said that, in addition to the standard criteria of NYHA class III symptoms and a recent history of a heart failure hospitalization, the other clinical feature he looks for in a patient who is a possible CardioMEMS recipient is a persistently elevated systolic PAP as measured using echocardiography.

“These are patients with evidence of an ongoing hemodynamic problem despite treatment, and I need more data to do a better job of getting their PAP down.” Although the PAP that patients self-measure once they have the device in place is their diastolic PAP, measuring systolic PAP by echo is usually a good surrogate for finding patients who also have a persistently elevated diastolic PAP, he explained.

Another important selection criterion is to look for the patients who are dying from heart failure rather than with heart failure, Dr. Heywood added.

“If heart failure is the major thing wrong, then we can improve their quality of life” by guiding fluid management with regular PAP measurement, especially patients with preserved left ventricular ejection fraction who have few other treatment options right now, he said.

The CardioMEMS HF System Post Approval Study is sponsored by Abbott, which markets CardioMEMS. Dr Heywood has been a consultant to and/or has received research funding from Abbott as well as Impedimed, Medtronic, Novartis, and Otsuka. Dr. Raval has been a consultant to Abbott. Dr. Joly and Dr. Vaduganathan had no disclosures.

mzoler@frontlinemedcom.com

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