Faculty Spotlight: Richard Cheng, MD
Comprehensive Care for Heart Failure
Cardiologist Richard Cheng, MD, is a double dynamo when it comes to helping heart failure patients. Not only is he adept at optimizing their medical therapy, but he is also an expert in implanting a variety of devices to help them feel better.
“There are very few people who are cross-trained in advanced heart failure, interventional cardiology, and structural heart disease, because the training is so long,” said Dr. Cheng. “When I first started, people said, ‘You should pick one,’ but for me, it was always about having a patient-centric approach. Our health care system has become so complex, and medical decision-making so complicated, that patients often feel lost in the system. It’s really important to me that my patients feel like they have clarity and a comprehensive plan for their cardiovascular health after a clinic visit.”
Born in Taiwan and fluent in Mandarin, Dr. Cheng moved to Vancouver as a child and earned his bachelor’s degree in biomedical engineering from Columbia University. He enjoyed helping people as a volunteer on missions to the Dominican Republic and Haiti and decided to become a doctor, earning his medical degree from the Geisel School of Medicine at Dartmouth University. Dr. Cheng then completed his internal medicine residency and fellowships in general cardiology, structural and coronary interventional cardiology, and advanced heart failure and transplant cardiology at Cedars-Sinai Medical Center in Los Angeles.
“It’s very special when a patient trusts you with their life,” said Dr. Cheng. “In cardiology, patients can come in with a large heart attack, but if you’re timely, careful, and do things well, they can go home two or three days later with minimal damage to the heart.”
Heart failure has many causes, but the end result is the heart’s inability to pump enough blood to the body. Symptoms may include fatigue, shortness of breath, and swelling in the legs and abdomen. “Heart failure affects millions of people in the United States, and can be a very limiting disease with a very high mortality rate,” said Dr. Cheng. “Often, patients may say they are fine, but when you ask more questions, they say things like, ‘I love golfing, but I can’t do it anymore.’ Then their partner jumps in and says, ‘He doesn’t leave the house anymore.’ You start realizing how much it has impacted their lives, and how much they are suffering. Now, using medications, devices, and resources that are available through innovation and research, we’re really able to help patients feel better and do things they enjoy.”
Dr. Cheng is an advanced heart failure specialist, caring for patients who need a heart transplant or a heart pump such as a ventricular assist device (VAD), as well as those in earlier stages of the disease. This is a rapidly changing field. For example, in 2015 a new combination drug, sacubitril/valsartan (Entresto) was approved in the U.S. Recent trials also showed that SGLT2 inhibitors, originally developed to treat diabetes, can also help heart failure. “Medications have gotten better, for sure,” said Dr. Cheng. “But pharmaceutical development is a slow process. There is a large population of patients who are on all the right medications, but still feel very limited. They used to be able to go grocery shopping, but now it tires them out. They have to catch their breath after walking a flight of stairs.”
New Horizons for Heart Failure Treatment
Traditionally, interventional cardiologists used catheters to open up blocked arteries that supply blood to the heart, using stents and performing angioplasty. While Dr. Cheng performs these procedures, he has further specialized expertise in minimally invasive transcatheter therapies, which deliver tiny collapsible devices to the heart via catheters inserted into a blood vessel. Transcatheter therapies are much less invasive than open-heart surgery, with faster recovery times and generally fewer complications.
“With structural heart disease, you’re not working with the vessels on the surface of the heart, but inside the chambers of the heart,” said Dr. Cheng. Transcatheter therapies originally focused mostly on replacing valves and patching holes in the heart. However, the field is rapidly evolving to also address problems acquired later in life, such as damage caused by a heart attack or viruses, or years of uncontrolled high blood pressure.
“Over the past three to five years, this field has really moved towards the heart failure population,” said Dr. Cheng. “Of every 10 devices under development for heart disease, perhaps seven are for heart failure patients.”
For example, in some patients the left ventricle severely enlarges in an attempt to compensate for the heart’s inefficient pumping mechanism, which leads to worsening heart failure. Currently there are devices under investigation which seek to help these abnormal hearts return to a healthier physiology by cinching the heart from inside and reducing its size. One such device is the AccuCinch LV remodeling device. UCSF is the first site in California to offer this device through clinical trials, and Dr. Cheng is the primary implanter at UCSF for it.
AccuCinch is one of many novel, minimally invasive device-based therapies for heart failure that UCSF offers. Other devices support the heart, providing assistance with pumping blood until the patient can receive a heart transplant or a more durable VAD. Yet other devices provide continuous information about a patient’s pulmonary artery pressures, which helps cardiologists better track how much fluid is building up in the patient’s lungs and tissues – the “congestion” in congestive heart failure.
One of the most commonly implanted devices is used to treat mitral regurgitation, which occurs when the valve between the left atrium and left ventricle fails to close properly, allowing blood to flow backwards in the heart. The MitraClip, which looks a bit like a binder clip, can be attached to the middle of the malfunctioning valve. Dr. Cheng positions the MitraClip so that it grasps the center of the two mitral valve leaflets – flaps that open and close like French doors with each heartbeat.
The clip holds these two leaflets together, creating two smaller openings which allow blood to flow forward when the heart pumps, but reduces backflow when the heart relaxes. Dr. Cheng’s own research has increased our understanding of this therapy and broadened its reach. For example, his investigations found that MitraClips could be effective even if patients had calcification around the mitral valve, that MitraClip recipients could tolerate a moderate amount of mitral valve stenosis as long as their regurgitation was adequately treated, and even some patients with very challenging anatomy could benefit from strategically placed MitraClips.
When placing a MitraClip, Dr. Cheng works in close partnership with an echocardiographer, who provides real-time imaging that allows him to visualize the inside of the heart. “We don’t have the luxury of [surgically] opening the chest, so everything is done by ultrasound and X-ray,” he said. Placing the clip is a very nuanced process, requiring skill and patience to ensure that it is positioned at the ideal location and angle to block the greatest area of leakage.
Sometimes the valve problem is caused by degenerative mitral regurgitation, in which the flaps or leaflets of the valve themselves are damaged. More recently, this device has been tested in patients with functional mitral regurgitation, in which the valve leaflets are normal, but do not seal properly for other reasons. Some of the main causes are due to heart failure: for example, if the left ventricle become abnormally enlarged to compensate for its poor pumping efficiency, or stiff scar tissue forms after a heart attack, restricting the heart’s range of motion. Both problems can distort the geometry of the heart, preventing the leaflets from sealing perfectly.
“If left untreated, patients with mitral regurgitation can have blood flowing backwards into the lung, which causes a lot of symptoms, and over time, it can hurt the heart as well, causing it to dilate further,” said Dr. Cheng. “A recent multicenter randomized control trial called COAPT published their three-year outcomes showing patients who received this device lived longer and better.”
There is some evidence that devices could also help patients with tricuspid regurgitation, which occurs when the valve between the right atrium and right ventricle is leaky, allowing blood to flow backwards in the heart. Dr. Cheng participated in the TRILUMINATE study, one of the first clinical trials to test the safety and efficacy of implanting modified MitraClips to treat tricuspid regurgitation. Early results have been promising.
“We have a term, ‘the forgotten valve,’ for the tricuspid space, because we don’t currently have good options for treating tricuspid regurgitation,” said Dr. Cheng, noting that the anatomy and causes of tricuspid regurgitation are perhaps even more complex than mitral regurgitation. “If patients go to surgery, the surgical experience tells us that the mortality is upwards of 10 percent, which is too high. However, these patients suffer. The regurgitation damages the liver and kidneys and causes pooling of fluid in the legs and belly. It’s a terrible disease. But there is hope. Now there are so many new devices on the horizon that the tricuspid valve is no longer forgotten.”
“The bottom line is that there are a lot of new trials and devices in the pipeline that are targeting different subtypes of heart failure patients,” said Dr. Cheng. “Many of these devices will be found to improve quality of life and survival. We are giving patients new options beyond medications that could help improve their lives.”
Taking the Long View
As exciting as all these developments are, Dr. Cheng tries to keep the big picture in mind. “For complex heart failure patients, devices may help them feel better, but they ultimately are only part of the puzzle,” he said. “You really have to think of the patient holistically. What is his or her overall plan and trajectory? Are they a candidate for transplant or a VAD? Heart failure doctors are like quarterbacks. When we look at patients, we think of multiple options. If this fails, what do we do next? How do we maximize their ability to do things they like, through medications, devices or other therapies? These are patients who really need a clear, comprehensive plan for their health care.”
Dr. Cheng is excited to work with device developers to bring the most promising clinical trials to UCSF, and to increase outreach efforts in the community to inform patients and doctors that UCSF can offer options to people who may not be candidates for existing therapies. “UCSF is such a hub of innovation and discovery,” he said. “People here are curious and want to try new things to help their patients in a thoughtful way.”
This approach dovetails with his own research, which has focused on optimizing patients and choosing the best therapies for each person. For example, he has studied the use of extracorporeal membrane oxygenation (ECMO), which is external heart and lung support for patients whose own organs are failing, as well as a heart pump called the Impella, and how well these approaches can bridge patients to transplant or to recovery.
Dr. Cheng’s other area of research is on coronary artery disease after heart transplant. Some patients develop this condition, also known as cardiac allograft vasculopathy, which is very different from the kind of coronary artery disease found in non-transplant patients. It is caused by inflammation-driven thickening of the arteries that supply the heart with blood, and is often associated with how well or poorly the patient is tolerating the transplanted heart. “If the patient is well-immunosuppressed, the body generally won’t attack the heart, and the patient doesn’t develop vasculitis,” he said. “But if for other reasons the heart is not a good fit for the patient, we may start seeing this condition.”
Some patients require stents to address this narrowing of the arteries, and Dr. Cheng and his collaborators have published a peer-reviewed paper documenting the largest known group of heart transplant patients who have undergone treatment for this specialized condition.
At UCSF, Dr. Cheng is embarking on several new investigations. For example, for patients who have excessive pressure in one of the two upper chambers of the heart, he and his colleagues are testing the effectiveness of intentionally creating a small hole between the chambers to balance out these pressures, using a device called an interatrial shunt. In another trial, his group is testing whether patients with pulmonary arterial hypertension – high blood pressure in their lungs – would benefit from strategically disabling some of the lung nerves to help arteries in the lungs relax.
Rapid Response for Cardiogenic Shock
In addition to his work in the cardiac catheterization lab and the clinic, Dr. Cheng is an attending physician in the Cardiac Intensive Care Unit, and also cares for other hospitalized patients with heart problems. He is heading up development of a new cardiogenic shock initiative, which seeks to rapidly identify and treat patients whose hearts suddenly are unable to pump enough blood to the body.
Cardiogenic shock is a serious condition that requires immediate treatment. “Multiple studies have shown that getting the shock team involved outside of 36 hours [of onset] really increases mortality,” said Dr. Cheng. “Patients don’t do well with a patchwork approach, because as shock progresses, their organs become irreparably damaged. It’s important to meet their degree of shock with the right support, whether that’s intravenous medication therapy to keep their blood pressure up, or using a temporary mechanical support device. It’s also important to create an exit strategy: we may be able to stabilize a critically ill patient with a temporary mechanical support device, but then what?
“That’s where it’s important to have a multidisciplinary team, with experts in heart failure, interventional cardiology, transplant surgery, and other disciplines,” said Dr. Cheng. “Together we can create a comprehensive plan for patients who are critically ill. The point is to have early recognition and bring in multiple specialties as soon as possible, rather than having shock patients go unrecognized for a day or two in the hospital or the community.”
While cardiogenic shock can be triggered by heart attacks, the majority of patients develop it for other reasons. For example, patients with underlying heart failure may have developed the flu and then taken a sudden turn for the worse, or may have eaten an excessively salty meal, which can exacerbate heart failure.
Dr. Cheng also wants to facilitate the referral process, so that physicians at other hospitals can easily transfer critically ill patients in cardiogenic shock to UCSF, where they can get the quaternary care they need.
Finding the Right Path for Each Patient
Whether he is caring for patients, conducting research, or teaching, Dr. Cheng appreciates the opportunity to improve the lives of heart failure patients. “These patients can be tenuous, and therapy decisions now may have long-lasting impacts,” he said. “This field demands our intense focus and careful management. I really enjoy making incremental changes for my patients to optimize their cardiovascular health, and finding the right path forward for each patient.”
In addition to medicine, Dr. Cheng enjoys running in Golden Gate Park and has completed 10 marathons and a 50K ultramarathon.