By Laura Johnson
The tip of a pencil. A dime. Two matchsticks. A USB drive. These are all phrases used to describe the size of some of today’s most advanced devices being used to diagnose, monitor and treat cardiovascular conditions. Thanks to technological innovations, medical devices are being “miniaturized,” which can lead to lower costs, greater convenience, less invasive procedures and shorter hospital stays.
For Worcester, Maine, resident Dan Wolpert, it was a tiny heart pump — the size of the tip of a pencil — that saved his life. Wolpert suffered a heart attack, followed by several cardiac arrests, at the age of 40. He had a 95% blockage in his left anterior descending artery, which is nicknamed the “widow-maker.”
Wolpert’s heart was functioning at about one-sixth its normal capacity. Prior to two stents being placed in his artery, the Impella 2.5 heart pump was placed in Wolpert’s heart to pump suffcient blood to other organs and tissues.
Following a heart attack, some heart muscle is permanently damaged while other muscle is temporarily stunned and requires time to start functioning again. The tiny heart pump bought time for Wolpert.
“The Impella 2.5 was able to give me all the blood ow support I needed while giving my heart a chance to rest and recuperate from the temporary stun from the heart attack,” says Wolpert, a Mended Hearts member at large.
The heart pump remained in Wolpert’s heart for almost 24 hours, allowing his heart to recover and preventing him from needing a heart transplant.
“I have been able to lead such an active life, with autocross racing, skiing and working full time, thanks to the tiny heart pump,” Wolpert says.
A variety of forces are advancing the evolution of miniaturization in the cardiovascular medical device market. The foundation of technologies developed for other industries, as well as the desire for convenient and functional medical devices, have played a significant role. In addition, demands for lower costs have accelerated the development of cardio- vascular devices that are less invasive and longer-lasting.
Mark Kremers, M.D., a cardiologist with Novant Health, Heart & Vascular Institute in Charlotte, N.C., points to the size of batteries as a key catalyst.
“The battery is the largest part of a device, and improved battery chemistry has enabled the creation of smaller devices,” says Dr. Kremers, who is also the chair of the American College of Cardiology National Cardiovascular Data Registry ICD Registry Steering Committee, which establishes a national standard for understanding treatment patterns, clinical outcomes, device safety and the overall quality of care provided to ICD patients.
For 21-year-old Westerville, Ohio, resident Colleen Myers, a small, insertable loop recorder has helped her avoid emergency doctor visits. Myers has a number of rare and complex congenital heart defects, and while she has always experienced chest pain and arrhythmias, they became worse as she got older. Her physician suggested implanting a loop recorder to get a 24/7 picture of what was happening with her heart.
“My initial thought was, ‘Am I going to look like a robot?’” can call my doctors and ask them to look at the recording instead of going in to have an emergency EKG,” Myers says.
A congestive heart failure (CHF) monitoring device with a sensor the size of a dime is helping Carole Sharp of Placentia, Calif., stay out of the hospital. After extreme shortness of breath and tiredness, Sharp was diagnosed with right-sided CHF a year ago. Her physicians recommended she use a CHF monitoring device that features an implanted sensor.
“It was explained to me that the purpose of the device was to manage the heart failure and keep me out of the hospital,” Sharp says. “That really appealed to me to have more control over my health.”
The implanted sensor wirelessly sends readings to an external patient electronic system. Sharp sends daily readings to her cardiologist who can then recommend medication adjustments based on the data.
So far the device is doing its job; Sharp has not been in the hospital for 14 months.
The implantable cardioverter debrillator (ICD) is another device providing more benefits to patients as it gets smaller. ICDs are useful in preventing sudden death in patients with known, sustained ventricular tachycardia or fibrillation. An ICD is a battery-powered device placed under the skin that keeps track of heart rate. in wires connect the ICD to the heart. If an abnormal heart rhythm is detected, the device will deliver an electric shock to restore a normal heartbeat.
“ICDs used to require open heart surgery so they were only used on patients who were in the worst shape,” Dr. Kremers says. “Now, with the smaller devices, which don’t require an open chest incision, we can implant them in more patients who have a meaningful risk.”
With the miniaturization of both ICDs and pacemakers, they are now usually combined, requiring only one device to be implanted.
While the shorter hospital stays, less invasive procedures, longer battery lives and greater convenience of miniaturized cardiovascular devices provide health and quality of life benefits to patients, physicians still must consider what is best for the patient.
“One size does not fit all,” Dr. Kremers says. “You have to select the device to use based on the features that best meet the patient’s needs. If it gets the job done, then yes, smaller is better.”