Noninvasive Home Assessment of Cardiac Filling Pressure to Identify Heart Failure Patients at High Risk for Readmission

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Congestive heart failure (CHF) is the most common reason for hospitalization in the U.S., with over 1 million admissions per year. Patients admitted with CHF usually need IV diuretics to promote fluid removal. The readmission rate is high – over 20% by 30 days, and 30% by 90 days post-discharge. This also presents an enormous economic burden - hospitalizations account for a large percentage of the $38 billion spent yearly on heart failure. One of the reasons for the high readmission rate is that it can be very challenging to detect elevated cardiac filling pressure until symptoms recur that prompt a return to the hospital. There is much enthusiasm for the potential of remote noninvasive monitoring to predict and reduce heart failure readmissions, but daily weights, vital signs and symptoms have limited sensitivity and specificity or are later indicators. We have developed the first device for assessing cardiac filling pressure noninvasively that can be used at home. It records finger photoplethysmography (ppg) continuously while also guiding and recording a standardized Valsalva maneuver into an expiratory pressure transducer. The latest prototype is hand-held, battery-powered, and communicates wirelessly with an iPad capable of remote transmission. The device is easy to use, employs technology that is robust and inexpensive, and testing takes only 5 minutes. We have shown that the output measure correlates with the invasive gold standard measures of left heart filling pressure - left ventricular end diastolic pressure (LVEDP) and pulmonary capillary wedge pressure (PCWP). More importantly, we have shown that it identifies clinically meaningful categories of elevated LVEDP and PCWP. Most recently, we have shown that LVEDP derived from the device on the day of discharge has high specificity for predicting heart failure readmission, need for outpatient IV diuresis, or death within 30 days after discharge. Sensitivity and specificity for predicting readmission may be improved by following LVEDP over time at home. In this Fast Track project, we intend in Phase I to develop further the automated waveform analysis algorithms, remote transmission capabilities, and prototyping necessary to conduct a home-based observational clinical study. In the clinical study in Phase II, post-discharge heart failure patients will test themselves at home twice a day for up to 30 days, and the data will be transmitted remotely. We will determine if LVEDP obtained twice daily predicts heart failure events (a combination of heart failure readmission, need for outpatient IV diuresis, or death) within 30 days after discharge. Our team has extensive combined expertise in waveform analysis, software development, medical device prototyping, project engineering, heart failure clinical investigation, and prior success in medical device start-ups. If the outcome of our observational clinical study is successful, the next step would be to conduct a multi-center interventional trial to determine if guiding therapy based on daily device testing reduces post-discharge heart failure events. The device has the potential to improve quality of life, reduce health care costs, and improve survival in patients with heart failure.