“It’s a cute little thing with sort of paperclips on each end,” says 73-year-old Carole Sharp. The Placentia resident isn’t referring to a whimsical handicraft posted on Etsy but, rather, the first and only FDA-approved medical device designed to keep heart-failure patients — like her — out of the hospital.
Called the CardioMEMS™ HF System, this dime-sized sensor is implanted directly in a patient’s pulmonary artery via cardiac catheterization. Once in place, CardioMEMS™ sets about its wireless work of measuring pulmonary-artery pressure.
Measuring pulmonary-artery pressure is both pivotal and preemptive. David Shavelle, MD, associate professor of clinical medicine at the Keck School of Medicine of USC and a staff member at the USC CardioVascular Thoracic Institute’s Center for Advanced Heart Failure, explains: “An increase in pulmonary artery pressure can signal an impending heart-failure issue, and we can initiate treatment before the patient’s condition reaches an advanced state.”
Prior to CardioMEMS™, cardiologists could do little more than monitor patients’ heart failure symptoms, including swelling in the lower extremities, abdomen, and neck veins; weight gain; fatigue; and shortness of breath.
It was the latter – while walking her shih tzu Sophie in April of this year – that prompted Sharp to dial 911. Three days later, she left the hospital with a diagnosis of diastolic
heart failure, which occurs when the heart can’t properly fill with blood during the resting period between each beat.
Sharp has a history of heart problems, including a 2001 heart attack and a 2013 double coronary artery bypass graft and aortic valve replacement at Keck Medical Center, under the surgical direction of Vaughn Starnes, MD, Hastings Distinguished Professor and Chairman of the Department of Cardiothoracic Surgery, Keck School of Medicine. While Sharp – who retired two years ago after spending five decades as a registered nurse – would have preferred to skip yet another heart-related diagnosis, at least said diagnosis was serendipitously timed. That’s because in May of 2014 St. Jude Medical received FDA approval for CardioMEMS™ based on a clinical trial showing that patients using the device had a 28 percent reduction in heart failure hospitalizations at 6 months, and a 37 percent reduction in heart failure hospitalizations over the entire follow up period.
Shavelle saw Sharp as an ideal CardioMEMS™ candidate. Not only did she meet the requirements of experiencing New York Heart Association Class III heart failure and being hospitalized for heart failure within the past 12 months, but she was highly motivated.
“When Carole developed heart failure she got fairly sick, and she really wants to do everything she can to prevent being readmitted to the hospital,” Shavelle says. USC Center for Advanced Heart Failure physicians have implanted some 40 CardioMEMS™ devices to date; Shavelle implanted Sharp on June 9 of this year.
Since then, Sharp starts her days by laying for five minutes on an antennae-embedded pillow next to a bedside monitor that sends pulmonary-artery and heart-rate readings to a secure website that can be accessed by Shavelle and Sharp’s local cardiologist. CardioMEMS™ data already has driven several changes to Sharp’s medications – changes predicated on preventing heart failure incidents.
Commenting on her post-CardioMEMS™ life, Sharp says that – although she doesn’t sense the device’s presence – she likes its impact. “It makes me feel much more confident,” she explains. “Now I don’t worry that something’s going to happen to me without warning. My medical team will get to me before that.”
by Carrie St. Michel