Heart failure monitoring device sends warnings in real time

The CardioMEMS device, now on trial at UCHealth, allows providers to monitor patients in real time
January 24th, 2020

Medical providers treating patients with heart failure are often playing a game of clinical catch-up. Weakened hearts allow fluid to build up, causing shortness of breath, fatigue and other symptoms that can be managed with medication adjustments. But patients may feel the effects only gradually and report the problems too late to avoid hospitalizations or emergency room visits.

profile shot of Dr. Natasha Altman who leading the CarioMems trial.
Advanced heart failure and transplant specialist Dr. Natasha Altman leads the CardioMEMS trial at UCH. Photo by UCHealth.

The delays have an enormous human and financial cost. Some 6 million people in the United States have heart failure. About one in five patients who have been hospitalized for heart failure-related causes go back to the hospital within 30 days. The readmissions contribute to a nearly $31 billion annual price tag for treating heart failure.

Beyond the financial burden that heart failure imposes, hospital readmissions worsen the quality of life for patients struggling with the disease, said Dr. Natasha Altman, an advanced heart failure and transplant cardiology specialist with the Heart Failure Clinic at UCHealth University of Colorado Hospital on the Anschutz Medical Campus.

“Every time a patient has a heart failure hospitalization or exacerbation, it is very hard for them to get back to the same degree of functionality as before,” Altman said. “With every subsequent readmission, people slowly get worse and worse.”

CardioMEMS device catching early heart failure signs

Altman is now the principal investigator for UCHealth in the GUIDE-HF trial of a system, dubbed CardioMEMS, that is designed to give providers an early-warning signal when heart failure patients’ conditions begin to worsen.

the CardioMems devise looks like a small figure eight.
The tiny CardioMEMS device measures pressure in the pulmonary artery. Rising pressure in the artery is an early warning sign of trouble for heart failure patients. Photo by UCHealth.

The centerpiece is a tiny sealed device that fits easily in the center of the palm of a hand. It holds a wireless sensor that providers implant in the patient’s pulmonary artery in a minimally invasive, outpatient procedure. The sensor measures the pressure in the artery.  If the pressure rises above the normal range, it’s a sign of fluid buildup that makes the heart work harder. Providers can then quickly adjust medications like diuretics, to keep the problem from worsening.

The system is relatively simple for patients to operate. They go home with an electronic unit and a pillow with an embedded receiver. Each day they are to lie on a pillow and press a button that triggers the CardioMEMS sensor to read the pulmonary pressure. The receiver sends the information to a secure website, where providers evaluate it and if necessary, contact the patient to make medication adjustments.

“The goal is to make checking the pulmonary pressures part of a patient’s daily routine, just like checking blood pressure,” Altman said. The study aims to determine if the device can help to prevent hospitalizations and emergency room visits caused by heart failure and improve patients’ survival.

UCHealth in CardioMEMS trial

The national trial seeks to enroll 3,600 patients at some 140 study sites, including UCH, UCHealth Memorial Hospital, UCHealth Medical Center of the Rockies and UCHealth Poudre Valley Hospital. It includes two phases. The first, which has just completed enrollment, took 1,000 patients who were randomized to one of two groups. All received the CardioMEMS device, but one group receives care based on data from the device, while the other receives standard medical care. In the second, single-arm phase, 2,600 patients will all receive the CardioMEMS device and receive care based on the data transmitted to providers.

The HF-Guide trial follows the CHAMPION trial, a smaller (550 patients) study of CardioMEMS. Altman said the trial produced positive results, but the Centers for Medicare and Medicaid Services and other insurers wanted more data to support the device’s effectiveness in reducing heart failure-related hospital readmissions.

“I’m excited to see if this will lead to a wider acceptance of this technology and give us an indication of whether or not it will be useful,” Altman said.

CardioMEMS candidates

couple poses together on bench in front of bushes
Michael Twitchell, with wife Debra, received the CardioMEMS device at UCH as part of a national trial. Photo courtesy of Michael Twitchell.

Count Michael Twitchell as one with a keen interest in the effectiveness of the CardioMEMS device. Twitchell, 56, built a 25-year nursing career, mostly in intensive care units and emergency rooms in hospitals on Colorado’s Western Slope. He was diagnosed in 2003 with a condition called restrictive cardiomyopathy that causes scarring and stiffening of the heart’s ventricles, making it difficult for them to fill with blood. For more than a decade after the diagnosis, though, he said he maintained a robust work schedule, trained in Tae Kwon Do and cycled up to 150 miles a week.

Then, in 2017, Twitchell “hit a wall.” The tipping point was a hunting trip with his son to the Grand Mesa (elevation 11,132 feet), where he spent a couple of miserable days, short of breath and fatigued. Twitchell at that point had transitioned to a desk job as a risk manager with the Grand Junction VA Medical Center and figured his bad mountaintop experience was the result of too much sedentary time and stress. With that, he headed for the gym.

“I decided to get back into shape over the next year,” he said. The workouts made him feel better for a short time, but soon the symptoms from the trip returned, along with sleepiness during the day. Those problems were a harbinger of a greater danger. Twitchell began experiencing atrial fibrillation (AFib), a scrambling of electrical signals that causes irregular heartbeats and increases the risk of blood clots and stroke. He had resting heart rates of 140 beats a minute (60 to 100 is normal).

His providers referred Twitchell to UCH, where Altman diagnosed him with heart failure, admitted him to the hospital and used medications to help his kidneys remove excess fluid from his body. He also received a new medication to control his AFib, but he ultimately required a procedure called ablation, performed by Dr. Matthew Zipse, a UCHealth electrophysiology specialist. The aim: use energy to scar tissue in the upper chamber, thereby short-circuiting the electrical misfirings that lead to AFib.

When heart problems persist

Twitchell’s hopes that the ablation would make him feel better failed to materialize. “My heart was still very weak,” he said. “I was short of breath and exhausted all the time.” Eventually the demands of work became too much for him. Altman told him that because of his heart failure, she could not clear him to work.

“It took a bit to convince me of that,” said Twitchell, who described himself as “a bit of a workaholic.” He was also at least a decade from normal retirement age. He pondered what he would do without work and how it would affect his relationship with his wife, Debbie, his adult son and daughter, and four grandchildren.

“I was very fearful of the future and what was going to happen with my family,” Twitchell said. “It was just a gut load of fear and panic and so many unknowns.” Ultimately, he needed an hour and a half to write a six-line email to his boss informing him that he couldn’t come back to work.

Avoiding the hospital and transplant

In fact, Twitchell’s heart was so weak that Altman discussed the need to put him on the hospital’s transplant list. He went through a two-day regimen of tests, joined the list Nov. 7, 2018 and is waiting for a new heart.

The ordeal didn’t end there. After exhausting trips back and forth from Grand Junction to UCH, including two more hospitalizations, he and Debbie moved to Aurora in June. Twitchell has been rehospitalized one more time since the move.

Avoiding return trips to the hospital remains a big concern and was a key reason Twitchell decided to enroll in the GUIDE-HF trial.

“Being in the hospital is incredibly stressful on both me and my family,” he said. After reading about the CHAMPION trial, he says he “basically demanded to be added” to the current one.

Altman implanted the CardioMEMS devise in Twitchell’s pulmonary artery in November 2019. Since then, he says, he’s not missed sending in a reading and has received calls from the UCH team asking him to adjust his dosage of diuretics. He believes CardioMEMS technology could help him avoid delays in treating his symptoms and stay at home rather than a hospital room. He said he’s also gotten some symptom relief from a different medication administered by Altman’s advanced heart failure and transplant cardiologist colleague Dr. Amrut Ambardekar.

couple plays with their grandbaby in living room, something the grandfather might not be able to enjoy it it wasn't for CarioMems device that monitors his heart.
Michael Twitchell, who awaits a heart transplant, hopes CardioMEMS device will help him manage his heart failure and give him more time with Debra and his grandchildren, including Samuel, shown here. Photo courtesy of Michael Twitchell.

Closer eye on heart failure symptoms

“It feels like my heart failure is under control and being monitored much more closely than it ever could be when I was just sending in my vital signs or weight when I didn’t feel good,” Twitchell said. “I have a lot more peace of mind knowing that there is real-time data that tells my physicians what my condition is.”

For her part, Altman said that however promising the concept behind CardioMEMS may be, only the randomized data from the GUIDE-HF study will definitively establish its effectiveness in improving patients’ lives and saving health care system resources. But she believes the approach is sound and could help many patients, particularly those who live in rural and underserved areas.

“I think there is a lot of benefit in getting very objective data that allows for adjusting medications in real time and changing patient outcomes,” Altman said.

For more information on the GUIDE-HF trial, contact Mercedes Zirbes: mercedes.zirbes@cuanschutz.edu.

About the author

Tyler Smith has been a health care writer, with a focus on hospitals, since 1996. He served as a writer and editor for the Marketing and Communications team at University of Colorado Hospital and UCHealth from 2007 to 2017. More recently, he has reported for and contributed stories to the University of Colorado School of Medicine, the Colorado School of Public Health and the Colorado Bioscience Association.