Interventional cardiology's role in treating CLI continues to evolve
There is a growing trend in interventional cardiology to treat critical limb ischemia (CLI) to prevent foot and leg amputations. This is viewed by many experts in the field as a major unmet need and has become a new vascular frontier for cardiovascular departments.
Transcatheter Cardiovascular Therapeutics (TCT) had a partnership with the American Heart Association (AHA) to provide interventional and endovascular education at the annual AHA meeting, and there was a big concentration on critical limb ischemia therapy at AHA 2022.
Sahil Parikh, MD, director of endovascular services at Columbia University Irving Medical Center and associate professor of medicine at the Columbia University College of Physicians and Surgeons, was the head of vascular programming at the meeting. He said there is rising interest from cardiology departments to treat critical limb ischemia. This is party to help them make up for dropping cardiovascular volume, but it can also expand the service line and improve outcomes.
Parikh thought it was ironic that interventional cardiology pioneer Andreas Gruentzig treated his first patients with home-made angioplasty balloons in peripheral artery disease (PAD), but it was the use of that technology in coronary arteries that really took off. Gruentzig presented those first PAD angioplasty cases at AHA more than 40 years ago, and today, peripheral angioplasty is new again at the meeting.
The complexity of CLI
"The CLI patient population is very complex ... these are patients that usually have rest pain, frank wounds or gangrene that have begun to develop and they need revascularization urgently," Parikh explained.
These patients also often have numerous comobidities and some of the sessions at AHA outlined what this patient population looks like demographically. These patients often have a very high prevalence of diabetes, hypertension and associated vascular disease in other beds, such as the carotids and coronaries. And the more risk factors you add on, the higher the chances of these patients ultimately losing a limb.
"In addition, there is a huge amount of racial and socio-economic disparity in the United States. Patients with CLI come in all ethnicities and sexes, but overwhelmingly minorities have a higher rate of amputation. There is no real reason for this other than social determinants of health and inequity in treatment," Parikh said.
Repeat procedures are often necessary
While interventional operators have become very good at revascularizing arteries all over the body, the legs remain a difficult vascular bed to treat. The durability of PAD revascularization has been a problem because of the high rate of restenosis in these patients. Balloon angioplasty is used in these patients, sometimes with stents, but he said the legs are a hostile environment to stents because of greater exposure to weight, impacts and bending that causes stent fractures and or can crush a stent. This is especially true at the knee and below the knee.
"The smaller the blood vessels and the longer the blockages are, the harder it is to reopen the vessels using an endovascular, minimally invasive technique. On the other head, doing open surgery on these patients can be extremely complex because the distance from the source artery to the target arteries is quite long, and the patients have a lot of other risk factors," Parikh said.
He also explained that this has led to many controversies in the field as to how to best manage these patients. For example, is angioplasty alone better than using stents? In many ways, PAD and CLI treatment is where interventional cardiology was 15-20 years ago before numerous large trials answered key questions.
Unlike coronary revascularization, there is not a large amount of clinical trial data to support various techniques and when to use surgery or endovascular approaches in patients. More clinical data is still needed to improve our understanding of this subject.
Parikh did note that, in the coronaries, drug-eluting stents have had excellent success in stopping restenosis in the vast majority of patients. These devices have not performed as well in the legs, however. If larger clinical trials can show definitive proof that stents, drug-coated balloons or bypass surgery lead to the best outcomes, it would help establish best practices for the standard of care.
Stroke and heart attacks among CLI patients
Even as improvements have been made, patients still face a higher mortality rate driven primarily by myocardial infarction and stroke.
"We are getting better and better at saving their limbs, but we are not better at saving their lives," Parikh said.
The focus has shifted over time, he explained, from just opening the blood vessel to seeing if you can actually do a lot more so that the patient can live longer. For this reason, treating PAD and CLI patients is well suited for the heart team approach where a multidisciplinary team of doctors should be caring for them. Parikh said caring for these patients really is a "team sport," and the focus should not just be on the person opening the blockages in the legs.
Dave Fornell has covered healthcare for more than 17 years, with a focus in cardiology and radiology. Fornell is a 5-time winner of a Jesse H. Neal Award, the most prestigious editorial honors in the field of specialized journalism. The wins included best technical content, best use of social media and best COVID-19 coverage. Fornell was also a three-time Neal finalist for best range of work by a single author. He produces more than 100 editorial videos each year, most of them interviews with key opinion leaders in medicine. He also writes technical articles, covers key trends, conducts video hospital site visits, and is very involved with social media. E-mail: dfornell@innovatehealthcare.com