Highly-skilled cardiologists at hospitals and cardiac centers around the world are gradually opting for interventional techniques to treat cardiovascular diseases.

As a result, the global interventional cardiology market is expected to grow at a compound annual rate of 7 percent from 2017 to 2021, according to a recent Technavio report.

Among the devices that caught their eye in the last year are bioresorbable stents. In July 2016, Abbott announced that it received FDA approval for its Absorb bioresorbable stent for patients with coronary artery disease.

Stent technology has evolved over the last 15 years, according to Tom Watson, senior clinical analyst at MD Buyline. The initial concept involved balloon angioplasty to open a partially blocked vessel and then placing scaffolding inside to keep it open.

After that, drug-eluting stents emerged, which held the vessel open and also provided a slow release of medication to prevent re-occlusion.

The most recent advancement in stent technology are the bioresorbable stents that dissolve after about three years. Conventional stents are made of metal, but Abbott’s Absorb is made of a naturally dissolving material.

Abbott’s thinking was if it made a stent bioresorbable, patients might not have to take the anticoagulant medications, according to Diane Robertson, director of health technology assessment at ECRI Institute.

A vessel can become irritated when a metal stent is implanted and starts to proliferate cells that build up and can close off the vessel again. Because of that, patients are required to take anticoagulant medication for at least two years.

“The question now is whether they work any better than the drug-eluting stents and whether a patient can stop taking these drugs sooner than they can with the drugeluting stents,” says Robertson.

That remains to be seen, but ECRI has conducted research to find out if the bioresorbable stent is as effective as the conventional stents. For the study, it reviewed 15 abstracts published between Jan. 1, 2010, and Feb. 4, 2016, that assessed the safety and efficacy of Absorb.

“ECRI Institute’s report found that Absorb BVS works as indicated for treating coronary artery disease, and it works as well as everolimus-eluting stents, biolimuseluting stents and bare metal stents,” says Robertson.

Robertson adds that hospitals have much to consider regarding stent technology. They need to decide whether they want to purchase the new stents, and if so, how many they want to stock as well as if they are going to continue to use the conventional stents.

[3/9/17 EDIT: Research published after this article's completion has shown patients receiving Abbott's Absorb stent may risk a higher chance of certain complications compared to patients with standard everolimus-eluting stents.

In those findings, thrombosis in the treated vessel occurred at a rate of 1.8 percent compared to 1 percent and heart attacks originating in the treated vessel also increased from 2.3 percent to 4.3 percent. Determining the pros and cons of absorbable stents is an ongoing investigation.]

TAVI coming to a hospital near you
Transcatheter aortic valve implantation was introduced about 15 years ago, and over the last decade it has grown as a therapy for higher-risk populations.

“The patient population that it’s being qualified for is gradually expanding. There are more sizes and more choices for the interventionalist to use, so that more patients can potentially be considered for this,” says MD Buyline’s Watson.



It takes a great deal of expertise and practice for a cardiologist to become proficient in TAVI, so it has historically only been performed at a few hospitals. However, Watson believes that it will become a more widely used procedure.

Much of the focus in medicine is shifting toward the preventive side and less on developing new techniques to treat heart disease. But with the growing elderly population, TAVI will remain a crucial treatment.



“Preventing it is a horse that’s already out of the barn for a lot of people,” says Watson. “They are still going to have to be able to address treating it.”

Current TAVI devices on the market require cardiac imaging to accurately position the new valve and a temporary pacemaker that makes the heart beat fast, so blood doesn’t circulate to the rest of the body during the procedure.

Researchers from the University of Cape Town in South Africa have developed a TAVI device that doesn’t require rapid ventricular pacing or cardiac imaging.

During the procedure, physicians use tactile feedback to place the device in the right position. A temporary backflow valve is used to stop the blood from leaking into the ventricle while the new valve is implanted.

If this new device comes to market, TAVI procedures can be performed in hospitals at a fraction of the cost of conventional TAVI.

An ounce of prevention is worth a pound of cure
“If we identified heart disease early enough, we would have ways to begin to modify their risk factors and lifestyle and keep them from ever getting to the point where they have to undergo a more invasive therapeutic procedure,” says Watson.

The health care industry is placing more of an emphasis on the noninvasive ways to assess a patient who may not have overt symptoms yet. That’s where cardiac CT and MR are playing a major role.



“If [the patient has] risk factors and that is combined with the genetic aspects of cardiac disease, they are going to be prime candidates for some of that early testing with cardiac MR or CT,” says Watson.

If a patient comes into the hospital with chest pain, lab work and EKGs are done and then an echocardiogram is usually the next step. An echocardiogram shows portions of the aorta and the clinician can piece them together.



“For a patient to get to the point where they have a cardiac MR, there may be areas of the echocardiogram that highlighted something that the MR would show better, like in the case of ruling out an aortic aneurysm,” says Sabrina Newell, clinical analyst at MD Buyline.

Cardiac MR technology has greatly improved in recent years with the University Hospital Lausanne in Switzerland developing a new technique last year.

The high frequency percussive ventilation technique involves the patient putting a mask over their mouth that’s connected to a ventilator that delivers small volumes of air. Instead of taking 10 to 15 large breaths, air is provided in 300 to 500 small puffs per minute.

Cardiac MR images are usually acquired in steps. The patient breathes in and holds it for each image, then recovers before the process is repeated. With this new technique, physicians can generate higher quality images with fewer artifacts in less time.

GE Healthcare introduced its ViosWorks cardiac MR software at the Radiological Society of North America annual meeting. It can perform in 10 to 15 minutes what typically takes 45 minutes to an hour.

ViosWorks can be used on GE’s existing MR systems and it shows blood flow in the heart in seven dimensions, including three in space, one in time and three in velocity direction.

Most hospitals have MR or CT technology that is functionally capable of performing heart exams, according to Watson. He believes more hospitals will invest in the cardiac software and workstation technology as health care payors begin to recognize their use for preventive care.



“Even though it’s expensive, it’s a lot less expensive than having to deal with [heart disease] after it’s so far advanced that it’s affecting [the patient’s] ability to work and function,” he adds.

Echocardiography is here to stay
The most commonly used imaging modality to diagnose heart disease is ultrasound. That’s because clinicians want something that is non-traumatic and easily accessible to the general population, says Watson.

In August 2016, GE launched its most advanced portable cardiovascular ultrasound system, Vivid iq. It can perform 4-D transesophageal imaging and it weighs less than 10 pounds.



“Our customers can take this system and put it in the trunk of their car and drive to another clinic,” says Al Lojewski, general manager of cardiovascular ultrasound at GE. “They continue to look for portable, laptop ultrasound systems because of the space premium in some of these care areas.”

For the Vivid S70, Vivid E90 and Vivid E95 cardiovascular ultrasounds, GE introduced its 4-D ultrasound software called cSound in July 2015. Since it depends on algorithms to interpret images, it has greater versatility than conventional hardware-based beam-forming machines that process each piece of data separately.

Transthoracic echocardiograms are inconclusive 10 to 15 percent of the time. GE believes that the cSound software will help to reduce that amount.

“If [the physician] doesn’t see a certain section of the heart because the patient’s rib is in the way and there’s noise in the image, then that would be [considered] non-diagnostic,” says Lojewski. “Overall they are not so concerned about the technology, but they are concerned about reducing non-diagnostic imaging patients.”

Philips Healthcare launched the Heart- Model tool for its EPIQ 7 ultrasound in July 2015. Conventional cardiac ultrasound technology takes up to three hours to perform 50 studies, but HeartModel can cut that down by almost two-thirds.

Cardiologists are under pressure to perform more studies in a day in this new health care environment. As a result, health systems are looking to purchase technology that can rapidly provide an accurate diagnosis.

“There are so many uses for echocardiography right now and the volumes have been increasing and increasing,” Dr. Wendy Tsang, a cardiologist at Toronto General Hospital, told HealthCare Business News when HeartModel was launched. “But it’s not like hospitals are hiring more physicians because they’re trying to maintain cost.”