SNOWMASS, COLO. – Advances in remote telemedical management show enormous promise as a means of preventing costly heart failure hospitalizations, William T. Abraham, MD, said at the Annual Cardiovascular Conference at Snowmass.
He characterized the decades-old conventional approach to heart failure management as a reactive strategy focused on making medication adjustments based upon weight changes and worsening signs and symptoms. But these physiologic markers of acute decompensation aren’t actionable; that is, they don’t occur until it’s too late to successfully intervene to prevent hospitalization.
It’s now clear that objective, measurable changes in intracardiac and pulmonary artery pressures as well as increases in lung fluid volume precede symptomatic decompensation episodes by several weeks. These early harbingers are reliably detectable by telemedical monitoring via small implantable pressure sensors or, noninvasively, using wearable sensors embedded in a vest.
“By moving upstream, we hope to develop a more proactive preventive approach to managing heart failure patients so that we can implement a medical intervention during this presymptomatic phase of worsening heart failure and avert a heart failure hospitalization,” the cardiologist explained.
That has already been demonstrated in several studies in which remote physicians checked the home monitoring data daily and promptly increased the dose of diuretics when pressure readings or lung fluid volume climbed above normal: The elevated readings quickly retreated and heart failure hospitalizations occurred much less frequently than with conventional management.
“Well-structured outpatient care could reduce the need for hospital admission, facilitate early intervention, prevent crisis management, and avoid complications or disease management in these patients,” Dr. Abraham observed.
Finding best telemedicine options
But this high-tech patient management strategy is not quite ready for prime time use in daily clinical practice.
“We’re still sorting through this field and trying to figure out the best telemedicine options,” according to Dr. Abraham.
He cited several recent large, well-conducted randomized trials that have persuasively shown that there’s no point in applying home telemedicine in order to quickly respond to changes in a heart failure patient’s blood pressure, weight, and symptom status.
“The horse is already out of the barn at that point in time,” according to the cardiologist.
For example, the(Better Effectiveness After Transition–Heart Failure) trial included 1,437 patients hospitalized for heart failure at eight California academic medical centers who were randomized to usual care or an intervention that combined health-coaching telephone calls and protocols for physician or nurse response to daily telemetric data on patient blood pressure, symptoms, heart rate, weight, and symptoms. The intervention turned out to have absolutely no effect on the 180-day rate of readmissions, which was roughly 50% in both groups ( ).
The(Patient-Centered Disease Management) trial was a multicenter Veterans Affairs study that randomized heart failure patients to usual care or a comprehensive intervention involving collaborative care by a cardiologist, psychiatrist, primary care physician, and nurse coordinator; screening and treatment for depression; and home telemonitoring of heart failure decompensation symptoms. The multifaceted intervention had no effect on the 1-year readmission rate ( ).
“To date, I would challenge you to find any adequately powered randomized, controlled trial in heart failure disease management that demonstrates that the way we’ve been doing things really keeps heart failure patients out of the hospital. So, it is time for a paradigm shift and some new technologies in our armamentarium,” Dr. Abraham said.
Several remote telemedical management systems for heart failure, which measure early preclinical harbingers of acute decompensation, have received Food and Drug Administration approval. Many more are in development. Dr. Abraham highlighted two approved systems for which he was a coinvestigator in clinical trials.
The CardioMEMS system uses a pressure sensor the size of a small paper clip that is placed in a branch of the pulmonary artery, where it readily becomes endothelialized. Device implantation can be carried out by any cardiologist who can perform a right heart catheterization, be it an electrophysiologist, interventionalist, heart failure specialist, or general cardiologist. It takes only about an additional 7 minutes to deploy the sensor following a standard diagnostic right heart catheterization. The system doesn’t use a battery and has no moving parts.
“Now, with more than 10 years experience, we have yet to see a sensor failure. It’s a highly reliable system,” according to the cardiologist.
Once a day the patient lies down, pushes a button, and the sensor is simultaneously powered up while the data on pulmonary artery pressure waveforms and systolic and diastolic pressures is extracted using radiofrequency energy.
In the randomized, multicenter, controlled, single-blind(CardioMEMS Heart Sensor Allows Monitoring of Pressure to Improve Outcomes in NYHA Class III Heart Failure Patients) trial, Dr. Abraham and coinvestigators demonstrated that pulmonary artery pressure-guided heart failure management reduced the rate of heart failure hospitalizations in the CardioMEMS group by 33% during the first 18 months of the trial and by 48% in the subsequent 13 months ( ).
“It’s important to note that the results were positive in diastolic as well as systolic heart failure. Patients with a baseline left ventricular ejection fraction of 40% or more saw a 50% reduction in the risk of heart failure hospitalizations, and those with an LVEF of 50% or more saw a 70% reduction,” Dr. Abraham said.
Other implantable hemodynamic monitors
Numerous other implantable pressure sensors are in development for management of heart failure, including other pulmonary artery pressure sensors as well as left atrial pressure monitors.
“You’re going to hear a lot more about this field of implantable hemodynamic monitors in the future,” the cardiologist predicted.
Dr. Abraham was also a coinvestigator in an observational study of a wearable sensor based upon radar technology developed for the military and subsequently applied to rescue searches through rubble for earthquake survivors. This remote dielectric sensing (ReDS) technology has been miniaturized, with the sensors embedded in an FDA-approved vest. The heart failure patient dons the SensiVest for 90 seconds once per day for measurement of the absolute amount of fluid in the lungs. The data is automatically transmitted to a secured site in the cloud, where the physician can review the results and adjust medications in response to early evidence of fluid buildup.
“The normal lung is composed of 20%-35% fluid. So when that fluid content is elevated, patients with heart failure have wet lungs and they’re decompensating. You increase their diuretics to bring it back down into normal range,” he explained.
In the observational study, conducted in Israel, hospital readmission rates were reduced by 87% through the use of ReDS-guided patient management using the system marketed by Sensible Medical Innovations. Dr. Abraham and his coinvestigators are now seeking to confirm those results in the prospective, multicenter, randomized, controlled U.S..
Dr. Abraham reported serving as a consultant to Abbott Vascular, Medtronic, Novartis, and St. Jude Medical.