To demonstrate how interventional cardiology has advanced, consider that over a two-week period this past summer, the Froedtert & the Medical College of Wisconsin interventional and structural cardiology team at Froedtert Hospital performed:
- Two transcarotid transcatheter aortic valve replacements (TAVR)
- A transaortic TAVR
- A Shockwave-assisted transfemoral TAVR
- An Impella® TAVR
- A bridging balloon aortic valvuloplasty
- A balloon-expandable, valve-in-valve TAVR with intentional old frame fracture
- A MitraClip™ transcatheter valve repair (TMVr)
- A first-in-Wisconsin intravascular lithotripsy, Shockwave-assisted, percutaneous transvenous mitral commissurotomy
The scope of the procedures and the complexity of the cases performed demonstrate how interventional and structural cardiology have advanced in providing minimally invasive options for patients who previously may have received open heart surgical procedures. The list of cases also attests to the deep well of capabilities at eastern Wisconsin’s only academic medical center for patients and referring physicians.
“The term interventional cardiology was born in the mid- to late-1980s,” said Michael Salinger, MD, interventional cardiologist, medical director of structural heart disease and MCW faculty member. “It differentiates from cardiology, as it involves advanced training to perform transcatheter-based therapeutic procedures.”
The interventional field has expanded in recent years from treating primarily vascular issues to addressing other components of the heart, such as its electrical circuits and valves, as well as repairing holes within the heart. Although no formal board certification currently exists, cardiologists who treat these nonvascular disorders of the heart are referred to as structural cardiologists.
Making Leaps Forward in Interventional Cardiology
Dr. Salinger said breakthroughs have been rapid and remarkable in both interventional cardiology and its structural branch.
“With PCI (percutaneous coronary intervention), we’re now using the third and fourth generation of drug-coated stents, which have thinner struts and better polymers that adhere the drugs to the stent scaffold,” he said. “We’re treating complex multivessel disease and bifurcation disease involving main and branch arteries, as well as chronic total occlusion, or CTO.”
Many of these patients with coronary artery disease are considered at high risk because of the nature of their blockages or other medical issues. Percutaneous therapy of these patients is known by the acronym CHIP, which stands for Complex High-Risk Indicated Procedures. Led by Salman Allana, MD, interventional cardiologist and MCW faculty member, the Froedtert & MCW interventional team is using advanced techniques to treat these patients effectively.
Whereas revascularizing a total coronary occlusion previously required coronary artery bypass grafting surgery, it can now be done less invasively using CHIP angioplasty techniques. With specially designed guide wires and balloons, interventional cardiologists can go through microchannels or collateral vessels — using either an antegrade or a retrograde approach — to open these large blockages.
“We have gained enough understanding and acquired technique skills and appropriate technology to be able to open vessels that have been closed for years,” Dr. Salinger said.
Interventional cardiologists are also deploying a percutaneous technology for left ventricular mechanical support. Impella, a tiny catheter-based electrical rotary pump, can provide temporary circulatory support for heart failure patients and serve as a safety net during complex angioplasty. Impella can also provide emergent support for heart attack patients in cardiogenic shock.
In a similar way, a percutaneously placed right ventricular support device — with the addition of artificial oxygenation — can help patients with damaged or injured lungs, patients who have had heart attacks that involve the right side of the heart, or those with holes in their heart after a heart attack.
Froedtert & MCW physicians under the direction of Lucian “Buck” Durham III, MD, PhD, cardiothoracic surgeon and MCW faculty member, discovered an unexpected application for this technology during the COVID-19 pandemic: patients in acute respiratory failure secondary to COVID-19.
“It provides miraculous, immediate support, and overnight we became recognized as a statewide resource for transcatheter right-sided COVID-19 support,” Dr. Salinger said. “We had some very gratifying outcomes — many patients who were failing ventilator support were able to come off the ventilators and begin walking around with their support devices in place. Percutaneous right ventricular support functioned as a bridge to recovery.”
Structural Heart Advancements Expand Therapeutic Options
Structural heart advancements at Froedtert & MCW Froedtert Hospital are also expanding the range of therapeutic options available in southeastern Wisconsin.
“Structural cardiology uses catheter technology to treat heart valve disease — both narrowed as well as leaky valves,” Dr. Salinger said. “In addition, structural cardiology employs catheter technology to treat abnormal holes in the heart, facilitate heart failure treatment and prevent stroke in patients with atrial fibrillation.”
Dr. Salinger has been deeply involved in the development of TAVR since its early investigational inception. He and his colleagues at Froedtert Hospital are currently researching the application of TAVR before patients with severe aortic stenosis have symptoms (EARLY TAVR clinical trial), and exploring TAVR for heart failure patients with impaired left ventricle function and moderate, but not yet severe stenosis (TAVR UNLOAD clinical trial).
An additional focus of Dr. Salinger’s work is expanding alternative access for TAVR.
“It’s a hierarchy where transfemoral access is our go-to approach with the least mortality and morbidity,” he said. “In fact, we were the first to use intravascular lithotripsy in Wisconsin in order to optimize borderline leg arteries so they could be used for transfemoral TAVR. More recent data has shown that transcarotid access is the next best approach as alternative TAVR access in terms of mortality and morbidity. At this time, there is no recognized alternative access TAVR procedure that we don’t provide at Froedtert Hospital. We get referrals every month from centers that have run out of ways to place a TAVR valve and are looking to us to use an advanced alternative technique.”
Making a Difference in Patients’ Lives
The following recent cases highlight how leading-edge interventional and structural treatments at Froedtert Hospital have made a difference to critically ill patients.
Example 1: A 60-year-old man arrived at Froedtert Hospital in shock from a critically narrowed aortic valve that had caused his left ventricle to fail.
“His disease had progressed beyond what could be treated with either TAVR or SAVR (surgical aortic valve replacement) and had progressed beyond the resources that the referring hospital in northern Wisconsin could provide,” Dr. Salinger said.
Upon arrival at Froedtert Hospital, the patient was immediately placed on Impella support to maintain circulation. A multidisciplinary team was then convened and recommended an initial balloon procedure on Impella support to unload the failing left ventricle and allow the heart to heal. The interventional team performed a balloon aortic valvuloplasty to stretch the valve open, buying additional time for the heart muscle to recover further and the patient to become a potential candidate for valve replacement. His condition and left ventricular function improved substantially, and about one week later, the heart team was able to remove the Impella and perform TAVR to replace the valve.
“It’s a good example of our multidisciplinary approach and having everyone involved help lay out a road map,” Dr. Salinger said. “So far, it has been a successful journey.”
Example 2: A 75-year-old woman with rheumatic fever treated surgically as a teenager was referred to Froedtert Hospital with severe, heavily calcified mitral stenosis that had developed as she aged. Due to extremely high pressure in her pulmonary artery, she had been declined for surgical reintervention at multiple medical centers. She was also turned down for transcatheter therapies including balloon dilatation of the valve at other medical centers.
“A highly calcified mitral valve is considered a contraindication for balloon dilatation because when you dilate a heavily calcified mitral valve, it tends to tear and you end up with a massive leak instead of a competent valve,” Dr. Salinger said. “She seemed to be a no-option patient.”
The Froedtert & MCW interventional team offered her a pioneering alternative, combining their experience with intravascular lithotripsy and their skill in catheter-based balloon dilatation. Physicians first delivered two Shockwave balloon treatments to break down the calcifications and create small microfractures, making the valve more pliable and more amenable to balloon expansion. They then performed a standard balloon dilatation, reducing the mitral gradient from 14 mmHg (severe stenosis) to 4 mmHg (mild stenosis) with only mild regurgitation.
“She had no increase in the degree of mitral regurgitation and went home the following day,” Dr. Salinger said.
The academic credentials of the Froedtert & MCW provider team enable them to use approved technology in innovative ways when no other alternative exists.
Example 3: In this case, a woman came to Froedtert Hospital with very heavy mitral annulus calcification. Open surgical replacement of the valve was not possible because removing the large “rock” of calcification would have left a sizeable hole in the heart. The extent of the calcification also precluded valvuloplasty. Lyle Joyce, MD, PhD, cardiothoracic surgeon and MCW faculty member, reviewed the case and said it was the most extensive mitral annular calcification he had seen in his career.
“This was a patient who likely would have been left untreated and would have survived only briefly,” Dr. Salinger said.
Instead, our team performed a transatrial, open transcatheter mitral valve replacement, essentially placing a balloon-expandable valve backwards in the calcified mitral valve. “By using a transcatheter technique with an opened chest, we were able to deliver the valve quickly, efficiently and flawlessly,” Dr. Salinger said. “The patient now has a perfectly functioning valve and an intact heart and no symptoms.”
Finding the Best Treatment Solution for Heart Patients
With such a comprehensive array of interventional and structural treatments at Froedtert Hospital, patients with heart issues and their referring physicians can, in many cases, choose advanced, nonsurgical options. When they do, they benefit from inherent advantages: small or even no incisions; shorter hospital stays; quicker recoveries and return to regular activities; and outcomes that are equal to, if not better than, surgery.
The objective, however, is not simply to help patients avoid surgery but to guide them to the right choice for their situation. To that end, a multidisciplinary Froedtert & MCW cardiac team reviews each patient case.
“Patients will be seen by both a member of the structural cardiology team, as well as the structural surgery team to initiate an evaluation of all of the potential options,” Dr. Salinger said. “At the end of the road, we will have done everything humanly possible to find the best solution for each patient. We leave no stone, traditional or investigational, unturned. Our goal is to find the best answer to each patient’s problem.”
For Our Referring Physicians:
Send a referral to the Froedtert & MCW interventional cardiology team
Physicians can contact the Access Center and describe the patient’s case to the intake nurse. In case of emergency, physicians should call the transport team at 414-805-4700. For non-emergent referrals, call 414-805-3666 or complete the New Patient Appointment Request form.