Andreas Gruentzig performed the first balloon angioplasty procedure on a coronary artery in Zurich, Switzerland in 1977. Having used the work of Charles Dotter, who had performed angioplasty of the leg a decade earlier, Dr. Gruentzig, in pushing the boundaries of modern medicine, sparked a revolution in interventional cardiology. Tragically, Dr. Gruentzig’s pioneering work came to an abrupt end in 1985 when the plane that he was piloting in a storm, crash-landed near Macon, Georgia, killing him.
However, he left a legacy, which we can thank him for many of the cardiovascular interventional procedures that are available throughout much of the globe today. The world witnessed further revolutions in interventional cardiology in the years following Dr. Gruentzig’s death. 1991 marked the first coronary stent to treat Acute Myocardial Infarction (AMI), after failed angioplasty. And in 1999 coronary stent technology saw advancement in the form of the first Drug Eluting Stent (DES), using Sirolimus, implanted in a human coronary artery.
Fast-forward to today, the field of cardiology continues to move forward, however these game changing leaps of technology are rarer. What we are seeing now are smaller, incremental steps in the improvement of surgical techniques and related technology. For example, when transcatheter valve replacement procedures were first conducted in trials about 20 years ago, the in-hospital mortality rate was approximately 50%. Refinement of transcatheter valve replacement procedures has decreased that figure to 1-2% today. And as a result of its increasing efficacy and safety, over 300,000 patients in the U.S. have received a Transcatheter Aortic Valve Replacement (TAVR) (i.e., this figure is approximately 500,000 globally) with approximately 720 U.S. based TAVR sites in existence. Given the growth of the elderly population, of whom 7-9% suffer from some severity of aortic stenosis (calcification and stiffening of the aortic valve), which is the main driver of TAVR, it is easy to forecast that this procedure will be performed with greater frequency and at an increasing number of medical sites.
Some of the questions you may be asking are where are we headed in the Cardiology world now? What are the related trends and what scientific breakthroughs are on the horizon?
In the way of obtaining expert perspectives and opinions on these questions, I interviewed retired Cardiac Surgeon and Professor Rainer Moosdorf, MD, PhD, FAHA who is now a Senior Medical Consultant and member of the Healthcare Shapers. Prof. Moosdorf has been devoted to cardiovascular surgery for 35 years. He served as a Medical Director and Full Professor of Cardiovascular Surgery for 24 years at The University Medical Center (UKGM), Philipps University in Marburg, Germany. He holds degrees in Medicine and Dentistry from Philipps University and Justus Liebig University in Giessen, respectively.
In the Questions & Answers to follow, you will get a sense that the name of the game today is refining and standardizing existing techniques and technologies to treat cardiovascular diseases, which the U.S. spends over $600 Billion annually to treat and approximately $1 Trillion annually on a global basis.
Computer science advances over the past 40 years are enabling new treatments to become a reality for patients. One of those may become Radiation Therapy to treat arrhythmias of the heart. While this was investigated in the 1980s, the technology needed to direct the radiation onto a very specific anatomical area of the beating heart was not available. But, now with Artificial Intelligence (AI) applications, this is close to becoming a reality.
One other promising area is cardiac stem cell implantation to treat heart failure. Globally, there are only approximately 3,500 hearts available for transplantation each year. Compare this with 64 million heart failure patients in the world, suffering from varying levels of severity; those in end-stage heart failure require mechanical support or a transplant in order to survive. Clearly, the number of heart failure patients requiring heart transplantation now far exceeds the number of available hearts. As far as total artificial hearts, the number of patients receiving these, globally, has remained fixed at around 4,500 per year. Given all of this, a new solution is direly needed. Cardiac Stem Cell therapy has the potential to be an alternative approach to heart failure treatment, however cell selection and implantation techniques need to be improved in order for it to work.
Please join me in viewing the future of cardiology through Prof. Moosdorf’s lens.
QUESTIONS & ANSWERS
1. Thornton: Why haven’t we seen the major advancements in interventional cardiology over the last three decades or so, such as the huge quantum leap made by Andreas Gruentzig in performing the first coronary angioplasty procedure in 1977?
Prof. Moosdorf: Big steps are rarer in the present day. We are now seeing smaller, incremental steps in the field of cardiology. The related technologies are improving, but further development of existing technologies is needed. As an example, 20 years ago when Transcatheter Aortic Valve Replacement (TAVR) first came onto the scene, the in-hospital mortality rate was nearly 50%, now it is around 1- 2%. So, we’ve come along way with the safety of that procedure.
It’s no longer about these big steps, the development is more scattered. However, over time
many important steps in medicine have been made, which have made today’s advanced procedures and therapies possible. We now have more continuous steps with new steps are on the horizon. For instance, with regards to Messenger RNA (mRNA) vaccinations, such as the Covid-19 vaccinations, this same technology can be applied to fighting some types of cancers. Therefore, in the future we may see physician ordering a mRNA cancer vaccine for an afflicted patient. As you can imagine, this could be a game-changer in the war against cancers.
Today we are not seeing the same type of major scientific and medical breakthroughs as the first heart transplant. Now we are observing smaller steps come together to enable medical advances.
2. Thornton: What do you believe are the top trends in cardiology, on a global basis, that will drive changes in this medical specialty within the next 20 years?
Prof. Moosdorf: We shouldn’t just look at rich countries. The medical community needs to focus more on prevention. We need to do more in the way of preventing people from getting sick in the first place. Quitting smoking is a big one that comes to mind.
Another issue is the current plague of obesity. We need youth to get more involved in sports and other activities that encourage physical exercise. In Germany we have a “Healthy Kids” program and the American Heart Association (AHA) has implemented a similar program for school children.
The second thing is that heart failure is becoming more and more of an issue (i.e., currently there are approximately 50 million people worldwide living with heart failure). We are seeing more people that are born with congenital heart diseases living later and later into life. This is of course a good thing, but as their life progresses, management of their diseases becomes more challenging, especially in situations such as during pregnancies.
Another example of this is a patient who had the Fontan Procedure (i.e., an open-heart surgery that is performed around the ages of 18–36 months old where problems with one of more of the ventricles of the heart are corrected) and survives into adulthood and beyond. These types of patients have to be monitored for their entire lives.
Also, we have to keep in mind that a heart transplant is not practical for every patient. What’s needed are better drugs to treat heart failure.
This is still at an early stage, but I believe that replacement of damaged myocardium (i.e., the muscle of the heart) with Cardiac Stem Cells, that is specialized myocardial cells, hold potential and could make a real difference for heart failure patients. The myocardial cells could even be created using 3D printing.
In 10 to 20 years, we may be able to replace the tissue damaged by fibrosis or myocardial infarction (MI). This type of therapy and procedure will require close cooperation between surgeons and cardiologists.
Another key trend are burgeoning therapies to treat heart arrhythmias. Closed chest procedures to treat atrial fibrillation (A-fib) are becoming more routine. Percutaneous treatments for A-fib will become more of the norm. One area that could be a game-changer in arrhythmia treatment is Radiation Therapy directed at the heart.
We already treat tumors with radiation, but the radiation must be targeted very precisely as to not affect or damage healthy, normal tissues. We are talking to within one square millimeter. You see, this small radiation therapy has small conduction. It is proton or heavy iron, micro-radio therapy.
This radiation treatment for arrhythmias is also in its early stage, however it is gaining steam. There are around 4 or 5 of these radiation treatment centers in Germany and some more in the United States. Major healthcare equipment manufacturers such as Siemens, General Electric, and others are producing applicable radiation generating systems, including proton accelerators.
The challenge in radiating organs such as the lungs or heart is that they are moving or pulsating. For example, if a patient has a tumor in the lungs, it is moving 1 centimeter up and then 1 centimeter down in rapid, continuous repetitions. In order to direct the radiation beam correctly and safely, we need to incorporate Artificial Intelligence (AI). We are coming ever closer to this treatment being a reality for the lungs or heart because the needed technology is becoming available. Radiologists will be focused on this technique for the next 10 years.
In the late 1980s and early 1990s, I worked with a Russian colleague, who is a Radiation Physicist. Back at that time, we discussed the possibility of radiation therapy for the heart. He said regarding arrythmias, looking towards the future, “Why don’t we use a radiation beam?”
The problem was that at this time we would have to arrest the heart in order to make the radiation therapy possible, and this of course was not practical given the clinical problem. We just didn’t have the adequate medical technology at this time. However, now we have the technology (i.e., AI) to track the radiation beam. With that, I believe that we will see a breakthrough in this sub-specialty cardiology field in around 10 years.
3. Thornton: In terms of cardiac imaging modalities (i.e., Echocardiography, CT, and MRI), what is the technical direction for each of these modalities? Will they all be utilized over the next 20 years or will one or more be replaced by another imaging technology or simply be removed from use? Is echo still relevant today?
Prof. Moosdorf: Echocardiography (Echo) will at least survive for the next 10 years. The advantages of echo are that its available pretty much everywhere and its relatively simple to use. Almost all cardiologists are trained in echocardiography. Echo can also be used to assist intraoperative procedures, such as for cardiac surgery. You can put the Echo system in the operating room and its simple, affordable, and easily available.
Echo has seen some remarkable development in recent years such as 3D echo and speckle tracking. Echo is becoming more sophisticated and we will likely see continued advancements in this modality over the next 10 years.
Computed Tomography (CT) has been used for cardiac scanning for a long time now. But the early screenings using CT of the coronaries were not so precise. Today, the quality and precision of the imaging has improved dramatically (i.e., today the most advanced, widely available CT scanners provide 128 slices and 320 slices on a very limited basis). It is possible that in coming decades CT will replace diagnostic cardiac catheterizations in some cases. Therefore, we could see a day where CT replaces angiography (i.e., where a radiopaque substance is injected into a patient in the Cath lab in order for the interventional cardiologist to visualize the inside, or lumen, of blood vessels). CT might become the imaging modality of choice for cardiologists and their patients.
We may also see CT used for more functional (i.e., visualization of the movement and contraction of the heart) investigation, such as to measure a patient’s Ejection Fraction (EF%) (i.e., a measurement of the strength of a patient’s heart contraction). 3D CT is something that is amazing and brings medical imaging to a whole new level. With CT, a physician can also visualize the heart valves well (i.e., in determining if there is an abnormality in motion and/or function). Also as compared with an echo, CT is not investigator or operator dependent.
I worked on many aortic dissection cases, where CT was used to assess the severity of this condition. And from a physician’s standpoint, CT provides that critical information fairly quickly. By using CT, you put the patient in the tube and within 30 seconds you can see the result.
However, one disadvantage of CT is that the patient will be exposed to radiation. Therefore, you can, for example, not use this modality on a pregnant woman. This is also an issue for younger patients (i.e., as there is a risk that the patient could develop cancer later on due to exposure to the radiation).
Moving onto Magnetic Resonance Imaging (MRI), the main problem with this modality is that it still takes a long time to perform the study (i.e., an MRI study can take up to an hour or more).
However, the advantage with MRI is that it is radiation-free. It also provides excellent visualization of the heart’s function (i.e., contrast can also be used in conjunction with the MRI to enhance the images) and movement of the heart walls (i.e., this can be used to get an accurate measurement of a patient’s EF%).
MRI also provides detailed micro-imaging. It allows a physician to visualize small areas of ischemia (i.e., lack of blood-flow to areas of the heart muscle). This modality is useful in assessing interstitial edema and cardiomyopathies. Additionally, it allows for the visualization of small areas of fibrosis.
In summarizing the future of cardiac imaging modalities (i.e., echo, CT, and MRI), these three modalities will allow physicians to discriminate across applications. For example, MRI is not used to identify coronary abnormalities. Echo on the other hand is a good and simple way to get a quick assessment of a patient’s EF%.
However, as mentioned the drawback with echo is that it is operator dependent. As such, it’s impossible to discriminate for 5% or less regarding a patient’s EF% measured via echo. But, an echo off-the-bat can tell a physician if their patient’s EF% is low, normal, or high (i.e., a condition often referred to as a hyperdynamic heart).
We are not just talking about hospitals. An echo can be performed in an out-patient setting in a physician’s private office. For example, suddenly a patient is not able to walk as well and becomes easily out of breath in doing so. In order for the physician to quickly rule-out if this is due to a sudden change in heart function, an echo can be performed in the private office. Now compare this with a CT, that the patient may not have for another 5 years. In this case the patient could be in late-stage heart failure by this point, putting their life at risk.
In cardiac evaluations, there are three levels of imaging modalities and they are: 1. Echo 2. CT, and 3. MRI. MRI would be required for a more micro evaluation. Each modality is different and optimized for certain conditions and clinical situations.
There are now hand-held echo systems and probes. These can be connected to smartphones. Clearly, this provides a very quick and easy way for a physician to visualize their patient’s heart (i.e., the accuracy and power of a hand-held ultrasound device still is not on-par with a standard cardiovascular ultrasound systems). But the physician performing the hand-held echo still needs to know how to put the ultrasound probe in the right place (i.e., between the intercostal rib spaces). Because of this, some physicians may need the proper training. Smaller probes may also be required.
4. Thornton: What are some key breakthroughs in interventional cardiology and what are key factors for determining the rate of their adoption in the clinical theatre?
Regarding, Tele-manipulation, the catheter does not move on its own; the guidewire has to be advanced into the patient’s arteries (i.e., which is inserted femorally or brachially) by the interventional cardiologist’s hands or via a robotic PCI system. Some of the key advantages of robotic PCI are precision and eliminating radiation exposure to the interventional cardiologist and Cath lab staff. This of course is a positive step and it will make Cath lab operations much more comfortable for cardiologists.
Laser atherectomy (i.e., a technique used when balloon angioplasty is inadequate to revascularize vessels with extremely dense, calcified atherosclerotic plaque) is good for debulking high-grade calcific atherosclerotic plaque. We were doing some of the first research on lasers for atherectomy applications back in the 1980s, including for coronary applications. Eventually the first excimer lasers came on the market (i.e., created by Spectranetrics Corp., since acquired by Royal Philips). The first related designs were created in the 1980s. We can open or revascularize the coronary arteries with the lasers, by vaporizing the atherosclerotic plaque. And then the myocardium can recover, more or less. I predict that these laser atherectomy devices will become a standard part of the interventional cardiologist’s tool kit.
We can now perform transcatheter aortic valve replacements (i.e., which are more common today) and mitral valve (i.e., these are less common; still in the trial stage), which are reducing the total number of open-heart surgeries that are performed each year.
Another therapy to treat heart failure on the horizon is Cardiac Stem Cell therapy. These can also be referred to as Myocardial Myocytes.
Various teams and centers are working on cardiac stem cell research and related techniques in countries such as Israel, Germany, and the U.S and further. They are working on repair of the myocardium using the stem cells.
This work is also being sponsored by the German Research Foundation, NIH, and similar Israeli institutions. This therapy has gotten off to a bumpy start. The first studies of cardiac stem cells were not correct. They were not homed in on the myocardium. Some side effects of the cardiac stem cell therapy were observed that happened to be beneficial for the heart. And also, some patients who received this treatment said that they felt their health improved. But it could not be proven that this was a direct result of the cardiac stem cell therapy. We are not yet there with this heart failure treatment. We need specialized cells that are resident in the heart.
I believe that within the next 10 years we will be able to implant real myocardial cells into the damaged areas of the myocardium. Some studies by German researchers showed that the cells implanted did not survive. The cardiac stem cells have to become integrated into the myocardium. As it stands, differentiation into myocardial cells is a problem.
5. Thornton: What are your thoughts on Bioresorbable Vascular Scaffolds (BVS); the 4thRevolution in Interventional Cardiology?
Prof. Moosdorf: I cannot say that Bioresorbable Vascular Scaffolds (BVS) (i.e., versus bare metal stents [BMS] or drug eluting stents [DES]) have reached a high level of efficacy. BVSs brought to market have been up and down. The idea of BVS is great. It has to be reabsorbed by the body, in the endothelium of the coronary arteries. It has to be removed somewhere. This is why this technology has been up and down. However, one day, it might become an alternative to DES. This tech is just not quite there yet.
6. Thornton: Where are we today with the progress and use of transcatheter valve replacement and repair? Is there still a clinical need for mitral valve reconstruction?
Prof. Moosdorf: Mitral valve (MV) replacement was a rarity early on in my career (i.e., as opposed to present day where a valve replacement is more frequently recommended, especially when talking about transcatheter techniques).
I performed open-heart surgeries on elderly patients (i.e., in their 60s to 80s) for functional mitral valve repair. I believe that mitral valve replacement is pushed too early, when mitral valve reconstruction has better outcomes. The push is also a function of medical device companies trying to bring their transcatheter valves. For example, transcatheter valve replacement is good for elderly patients (i.e., who have low chances of surviving open-heart surgery), but not for younger patients.
We can do a reconstruction of the mitral valve via transcatheter using the MitraClip and meanwhile also more complex devices. They are implanted through the catheter. But we need to further fine-tune these techniques. We need complex centers for more complex cases.
Regarding the treatment of mitral valve disease, for young women or men who have mitral valve disease and require intervention, the transcatheter valve replacement is not ideal. In these cases, mitral valve reconstruction is preferred. This can be done using a mitral valve (support) ring. Therefore, I would not recommend a transcatheter valve replacement for a young woman.
The reason for this is that they can live with their own (natural) valve for 40 years, whereas a replacement valve (bioprosthetic or fully prosthetic) may only last from 10 – 20 years. I recommend reconstructing the valve as much as possible. I performed a lot of mitral valve reconstructions early in my career.
7. Thornton: Now here’s the million-dollar question. Regarding open-heart surgery, is this a dying specialty given the advent of more and more transcatheter enabled procedures, such as transcatheter aortic and mitral valve replacement?
Prof. Moosdorf: We will see a reduced number of open-heart surgeries performed moving forward, but the surgeries that are performed will be more difficult and complex. Open-heart surgery is still required in many cases such as a failed percutaneous catheterization intervention (PCI) or to correct a congenital heart malformation. There are many other reasons; these are just a few examples. Therefore, we will see the open-heart surgeries less often, but they will be more complicated to perform.
Back in the day, we still performed open-heart surgeries for single coronary artery bypass grafts (CABG) or reconstruction of the coronary arteries. But today open-heart surgery is still required for triple-vessel disease. And then we still need open-heart surgery to intervene in the case of an aortic dissection (i.e., where the inner layer of the large blood vessel branching off the heart (aorta) tears); this is what caused the death of American actor, John Ritter. We will continue to see complex aortic dissections, which can be very difficult and risky to operate on.
In the future, we will see on a more regular basis, surgeons and cardiologist working together in the way of taking on complex cases. We need cardiac surgeons spread out and available on a wide geographic basis. It’s not practical to have them concentrated in just one major city or area. Getting a patient suffering from a diagnosed aortic dissection (i.e., usually detected with a transthoracic or transesophageal echo or CT) into the OR is very time-sensitive. Their life depends on prompt surgical intervention. For example, if a patient with an aortic dissection is in San Francisco and has to fly from San Francisco to Washington, D.C. or from Frankfurt to Hamburg for the needed surgery, they’re dead; they won’t make it.
8. Thornton: What does the future hold with regards to the education and training of new cardiologists? Will we still see the various sub-specialties in cardiology (i.e., interventional cardiologists, electrophysiologists, pediatric cardiologists, etc.)?
I think there will be a number of things that will happen in the near future with regards to new cardiologist training. We will have “heart specialists”, not cardiologists, not surgeons, etc... There will be more cross-training of physicians in the cardiology field, therefore the historical titles and practices of cardiology sub-specialties will change.
As a cardiac surgeon, I was doing interventional procedures in the 1980s. I did interventional procedures in the early days where I had cardiologists by my side. You need a basic training to be a cardiologist of course. But I predict in the future that there will be no “specialists” per se. In this future, all cardiologists will be able to reach the epicardial surface of the heart or remove infected intracardiac device (ICD) wires.
With regard to cardiac specialization, it is no longer vertical, but horizontal in terms of the way that cardiologists will be trained and what they will each be capable of in the future. The training and day-to-day activities of cardiologists will be focused more on certain anatomical parts of the heart. And specialized cardiologists will be able to treat congenital heart defects, both in children and adults versus the sub-specialty of pediatric cardiologists only that we see today. Cardiologists and cardiac surgeons will cooperate even closer in heart teams focused on special disease entities as valvular or coronary disease or congenital defects or arrhythmias. We will however still have general cardiologists probably in more rural areas.
9. Thornton: Do you have any final thoughts?
We are seeing promising innovations in cardiology. Heart medicine will change. Specialization will change from new forms of specialization that are focused on certain areas of the heart, such as radiation-based arrhythmia therapies. We will also see specialization for heart valve disease and electrophysiology therapies. And there will likely remain specialists who treat specific congenital heart defects.
Very specialized areas will become more important to treat congenital heart defects as these patients age into their 30s, 40s, and 50s and especially if they are going through a pregnancy or play sports. Both of these things can be risky for them and challenging to manage from a physician’s standpoint.
Cardiology training and cardiology department operations will no longer be vertical, but horizontal. This new model for cardiologists and cardiac surgeons will be instituted slowly but surely over time. It is not yet instituted, but major heart centers are developing these new models.
We have the same healthcare problems in Europe as in the U.S., such as Physician shortages. But we must build this new train as it is moving down the track.
END OF INTERVIEW