From Your Heart to Your iPhone

From Your Heart to Your iPhone

  10:11:00 AM    Science Lover

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A new app gets data from an implanted device and can share it with the patient, doctors, and family.

A smart-phone app under development for heart-failure patients allows them to keep track of the pressure inside their heart as measured by an implanted sensor. That data could help patients adjust their medication to maintain a healthy pressure, much as diabetics do with insulin and blood sugar readings.

Called Pam+ (for "patient advisory module"), the app is being developed by researchers at the University of Southern California in collaboration with medical device maker St. Jude Medical. The researchers hope it will help patients better manage their health and reduce hospitalizations, which are responsible for much of the $40 million in health-care costs linked to heart failure.

In congestive heart failure, pressure builds up in the circulatory system and the heart fails to pump blood adequately to the rest of the body. Fluid pressure changes by the day, and monitoring those fluctuations continuously is essential to treating heart failure effectively. A number of implanted devices are now under development to monitor this pressure, giving patients and doctors real time data.

The PAM+ app works in conjunction with an external device—developed by St. Jude and currently in clinical tests—that is placed over the heart, where it charges the implanted sensor and downloads data from it.

The data is forwarded to a server at St. Jude that analyzes it and returns, via the app, the latest readings and information about ongoing trends. A patient who has regularly monitored his or her heart pressure over a week will see a graph of pressure readings along with the message "Your heart thanks you." Users can easily share their data with their health-care team and family.



"We want patients to be able to access data but also to be rewarded and encouraged on a daily basis, so they don't feel like their whole life is a diet," says Leslie Saxon, a cardiologist and director of the Center for Body Computing at USC, who helped develop the device.

Previous research conducted by Saxon showed that remote monitoring can improve the health of heart-failure patients and lower health-care costs. She unveiled a prototype of the app at the Body Computing conference in Los Angeles today.

Users get points for monitoring their pressure—points that might eventually be tied to iTunes or Amazon credit. "Even a traditional payer would love to reward this type of behavior," says Saxon.

She believes an app like this can also change the nature of doctors' visits. Rather than a physician giving a patient the latest test results, taken at a few points in time, the patient can show the doctor measurements of heart pressure over weeks and months, and together they can discuss the trends these reveal.

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High-resolution imaging technology reveals cellular details of coronary arteries

High-resolution imaging technology reveals cellular details of coronary arteries

  12:53:00 AM    Science Lover

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Researchers at the Wellman Center for Photomedicine at Massachusetts General Hospital (MGH) have developed a one-micrometer-resolution version of the intravascular imaging technology optical coherence tomography (OCT) that can reveal cellular and subcellular features of coronary artery disease. In a Nature Medicine paper receiving advance online publication, the investigators describe how microOCT – which provides 10 times greater resolution than standard OCT – was able to show individual arterial and inflammatory cells, including features that may identify vulnerable plaques, within coronary artery samples.

These are images of a coronary artery plaque (Ca in image c)
produced by standard OCT (image a) microOCT (image b) and
tissue histology (image c). Credit: Nature Medicine / Wellman
Center for Photomedicine at Massachusetts General Hospital

"MicroOCT has the contrast and resolution required to investigate the cellular and subcellular components underlying coronary atherosclerosis, the disease that precipitates heart attack," says Gary Tearney, MD, PhD, of the Wellman Center and the MGH Pathology Department, who led the study. "This high level of performance opens up the future possibility of observing these microscopic features in human patients, which has implications for improving the understanding, diagnosis and therapeutic monitoring of coronary artery disease."

A catheter-based technology, OCT uses reflected near-infrared light to create detailed images of the internal surfaces of blood vessels. Although the technology is already being used to identify arterial plaques that are likely to rupture, standard OCT can clearly image only structures larger than 10 micrometers (millionths of a meter). Using new types of lenses and advanced imaging components, microOCT is able to image structures as small as one micrometer, revealing in intact tissue the detailed information provided by the prepared tissue slides of traditional pathology much faster and in three dimensions.



The researchers describe how using microOCT to study human and animal coronary artery tissue revealed detailed images of:

• endothelial cells that line coronary arteries,
• inflammatory cells that contribute to the formation of coronary plaques,
• smooth muscle cells that produce collagen in response to inflammation,
•  fibrin proteins and platelets that are involved in the formation of clots

MicroOCT also produced detailed images of stents placed within coronary arteries, clearly distinguishing bare-metal stents from those covered with a drug-releasing polymer and revealing defects in the polymer coating.

"When we are able to implement microOCT in humans – probably in three to five years – the 10 times greater resolution will allow us to observe cells in the coronary arteries of living patients," says Tearney, a professor of Pathology at Harvard Medical School. "The ability to track and follow cells in three dimensions could help us prove or disprove many theories about coronary artery disease and better understand how clots form on a microscopic level. Improved definitions of high-risk plaques will lead to greater accuracy in identifying those that may go on to rupture and block the coronary artery, and the ability to monitor healing around implanted devices like stents could reduce the number of patients who must be on anticlotting medications, which are expensive and have side effects."

Provided by Massachusetts General Hospital

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Wireless Heart Implant Reduces HospitalizationsA pressure-sensing implant helps heart-failure patients stay healthy.

Wireless Heart Implant Reduces HospitalizationsA pressure-sensing implant helps heart-failure patients stay healthy.

  10:29:00 AM    Science Lover

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A wireless sensor developed by Atlanta-based CardioMEMS reduced the number of hospitalizations in patients with heart failure by 39 percent. The tiny implant monitors fluid pressure in the pulmonary artery and transmits the data wirelessly to physicians, who can adjust patients' medications accordingly.

Researchers say the sensor may significantly lower health-care costs and improve quality of life for people with congestive heart failure. The device is one of several prototypes being developed by CardioMEMS and other medical implant companies to provide continuous, personalized wireless monitors for such patients.

Pressure patrol: A new wireless sensor the size of a paper
clip measures fluid pressure in the pulmonary artery. The
metalloops on either end anchor the sensor to the artery
walls, while the self-contained transducer in the middle
takes pressure readings. The sensor is activated by radio
frequency, transmitting data wirelessly to physicians
via modem.Credit: OSU Medical Center/CardioMEMS

"I think the study shows this kind of device is incredibly useful in improving outcomes in patients and directing therapy," says Marc Jay Semigran, medical director of the Mass General Heart Failure and Cardiac Transplant Program, who was not involved in the study.

Hospitals admit 1.1 million adults each year for congestive heart failure, a condition in which pressure builds up in the circulatory system and the heart fails to pump blood adequately to the rest of the body. The American Heart Association estimates that the chronic condition costs the health-care system $29 billion per year. CardioMEMS aims to reduce that figure by providing an accurate way to continuously monitor patients after they've left the hospital.

The device is implanted in the pulmonary artery, an area that carries a low risk of clotting. It is smaller than other implants under development because it does not require a battery or a wire to take pressure readings. Two metal loops hold it to the sides of the artery, and a pressure transducer records the flow of fluids through the blood vessel. The sensor is powered externally by a receiver built into a pillow. When a patient lies on the pillow, the sensor is activated to take measurements and send them wirelessly to a computer, where physicians can review the data. In a large six-month clinical trial published this month in the Lancet, 550 patients from 64 centers across the United States were equipped with the device and instructed to take readings once a day. Patients were divided into two groups. The first took medication instructions from physicians who monitored the sensor data. The second took instructions from physicians who relied on traditional indicators like weight and blood pressure. Over the six months, patients in the first group experienced 39 percent fewer hospitalizations than those in the second.

Today, physicians often assess pulmonary pressure when initially evaluating a patient, but they do so far less frequently in follow-up evaluation. That's because the measurement requires doctors to snake a catheter into a patient's heart and inflate a balloon. However, fluid pressure changes by the day, and monitoring those fluctuations continuously is essential to treating heart failure effectively.

"Over the years, we found that pressures go up long before patients develop symptoms and call a doctor to say they're sick," says Philip Adamson, director of the Heart Failure Institute at Oklahoma Heart Hospital, the principal investigator in the CardioMEMS clinical trial. "By utilizing the pressure sensor information, we're given the ability to make changes in medications long before patients bring themselves to the doctor, and that's how we reduced hospitalizations."

Over the past few years, several companies have jockeyed to be first on the market with a continuous pressure-sensing cardiac implant. In 2007, Medtronic failed to get FDA approval for its sensor, a stopwatch-size, battery-powered implant wired to the heart. The device reduced hospitalizations by 22 percent, but FDA regulators did not consider that worth the risks associated with implanting it. Researchers also found that the wire connecting the sensor to the heart degraded over time.

CardioMEMS is currently seeking approval for its sensor from the U.S. Food and Drug Administration and has submitted results from the clinical study for FDA review. In the next two or three years, the company plans to integrate the sensor's receiver into a patient's cell phone, which will be able to instantly read pressure data and upload it for both physicians and patients to review.

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