Five Questions with Lauren Sharan Ranard, MD, MS, Interventional Cardiologist
We spoke with Lauren Sharan Ranard, MD, MS, about joining the faculty at Columbia—including her clinical role with the Columbia Structural Heart and Valve Center and her research with the Cardiovascular Research Foundation.
Can you tell us a bit about yourself and your role here at Columbia?
I was born in New York, but my family moved several times while I was growing up. I spent five or six formative years in Tokyo after my parents were transferred there for work. Living there gave me a love of sushi and a lasting appreciation for community, precision, and attention to detail.
I attended Cornell for undergraduate studies, went on to medical school at Thomas Jefferson University in Philadelphia, and completed my internal medicine residency at Duke. I then came to Columbia for my general cardiology fellowship, followed by advanced fellowship training in interventional and structural cardiology. By the time I started my fellowship, I knew I wanted to pursue a career in interventional and structural heart disease—and I’ve been at Columbia ever since.
At Columbia, I perform both coronary and structural interventions and see patients at both the main campus and Westchester. In addition to my clinical work, I spend part of my time at the Cardiovascular Research Foundation, where I’m involved in cardiac CT core lab research as well as preclinical work developing and testing new heart valves at the Skirball Center for Innovation.
What made you decide to become a doctor?
I think it really started in high school. I was always drawn to the sciences, and I participated in a program that allowed students to shadow professionals in different fields. That early exposure to medicine made a strong impression on me.
When I went to Cornell, I became an EMT, and that experience solidified my interest in medicine. I loved being on the front lines of patient care—responding to emergencies, thinking quickly, and helping people during some of their most vulnerable moments. It was incredibly meaningful to be able to make an immediate difference, even in small ways.
In medical school, I was still figuring out what kind of doctor I wanted to become. After studying anatomy and physiology and beginning my clinical rotations, I found myself increasingly drawn to procedural specialties.
During my internal medicine residency at Duke, I had the opportunity to spend several months in Adelaide, Australia, doing global health work. While there, I worked in the cath lab and was exposed to both coronary and structural procedures. It was incredible to see how dramatically you could improve someone’s quality of life in such a short period of time. A patient might come in with severe chest pain and leave the next day feeling well. Someone with heart failure from aortic stenosis could have a transcatheter aortic valve replacement (TAVR) and quickly regain function.
Seeing how many conditions that once required open surgery could now be treated with minimally invasive techniques was transformative for me. That experience solidified my decision to pursue interventional cardiology.
Can you tell us about your research?
When I started my fellowship at Columbia, I knew I wanted to focus on interventional cardiology. I became involved in several research projects related to valve disease and left atrial appendage closure.
One question that really interested me was the difference between coronary and structural interventions. In coronary work, we often don’t have detailed anatomic information before the procedure. Sometimes we have a cardiac CT scan, but in many cases, patients present with chest pain and we only fully understand the anatomy once we’re in the cath lab.
Structural interventions are very different. Nearly all of the key decisions are made before the patient ever comes to the table, using CT and echocardiographic planning. That contrast sparked my interest in cardiac CT and imaging-based procedural planning, and it naturally expanded into device development research.
I’m especially drawn to the field of structural heart disease because we can now repair or replace heart valves using catheters inserted through blood vessels in the leg—procedures that, not long ago, required open-heart surgery and a sternotomy. The ability to offer patients less invasive options with faster recovery is incredibly motivating to me, and it’s a major reason why I’m committed to developing new and better transcatheter valve therapies.
At the Skirball Center for Innovation, I’m involved in several projects focused on transcatheter mitral valve therapies that are currently under development. While transcatheter aortic valve replacement (TAVR) for aortic stenosis is now a mature therapy with highly reproducible outcomes, many other areas in structural heart disease—such as aortic regurgitation, mitral regurgitation, and tricuspid regurgitation—are still evolving. There are numerous devices in development, and I’m interested in helping evaluate and refine these technologies.
I also work in the cardiac CT core lab, where I collaborate with industry partners on early feasibility and pivotal trials, supporting patient screening and imaging analysis.
How is the imaging used to plan the procedure?
Every patient is unique, and in structural heart disease it’s essential to fully understand and map each patient’s anatomy in order to offer the most personalized and effective valve therapy. For mitral and tricuspid interventions, planning is truly multimodal. We rely on both cardiac CT and echocardiography—it’s never one or the other. We integrate detailed imaging findings with what we know about the patient clinically.
For example, some transcatheter mitral and tricuspid valve replacements require anticoagulation afterward, and not every patient can tolerate that. So we combine patient-specific factors with precise anatomic information to determine the best therapy.
Imaging helps us answer several critical questions: Will a transcatheter therapy fit this anatomy? What device size should we use? Is transcatheter delivery technically feasible? CT technology has advanced tremendously over the past decade, and in many cases we can now plan the catheter path before the procedure even begins. We often go into the cath lab knowing which device we will use, what size it will be, and even estimating how much space will remain in the left ventricular outflow tract after placing a mitral valve device. The ability to predict these outcomes in advance has transformed the field and is one of the reasons I find structural heart disease so compelling.
The mitral valve, in particular, presents unique challenges. Its anatomy is highly complex and far more heterogeneous than the aortic valve, making a one-size-fits-all approach unrealistic. Disease etiology varies significantly from patient to patient, and device selection depends not just on annular size, but on surrounding structures and how the device will interact with the rest of the heart.
Although transcatheter aortic valve replacement is now well established, the mitral and tricuspid spaces are still evolving. There is now a commercially approved tricuspid replacement device, and recently approved transcatheter mitral replacement technologies, but many additional devices remain in development. Even with approved therapies, not every patient is a candidate because anatomic variation is so significant.
Ultimately, the challenge—and the opportunity—is understanding how a device will affect the entire cardiac structure. It’s a complex problem that cannot be solved with a single solution for everyone, which is exactly what makes this work so interesting.
Where do you think the next interventional breakthrough will come? What’s the next big headline?
I think one of the next big headlines may come from left atrial appendage (LAA) closure. The field has already seen significant growth over the past several years as indications have expanded. For example, there is now an indication for combined ablation and left atrial appendage closure procedures.
Traditionally, LAA closure has been reserved for patients with atrial fibrillation who have a high bleeding risk and are poor candidates for long-term anticoagulation. One of the major advantages of LAA closure is that it can allow selected patients to avoid lifelong blood thinners and the associated bleeding risks, lifestyle limitations, and medication burden. For many patients, that is a meaningful quality-of-life consideration.
Even more interesting are two major trials evaluating LAA closure in broader patient populations. These studies are looking at an “all-comers” approach, in which patients with an indication for anticoagulation for atrial fibrillation are randomized to either LAA closure or medical therapy. If the results are favorable, they could significantly expand the role of LAA closure and potentially be practice-changing.
Another headline I’m watching closely is in aortic regurgitation (AR). We are anticipating potential approval of a dedicated transcatheter AR device in the near future. Unlike aortic stenosis—where TAVR is now well established—there is currently no FDA-approved transcatheter therapy specifically for AR in the United States. Having an approved device in this space would represent a major step forward for patients who are not ideal surgical candidates.
I’m also excited about advances in transcatheter mitral therapies. I’ve been involved with some of these technologies from early in their development, including preclinical work, and it’s been incredibly rewarding to see them progress. Several of these devices are entering early feasibility or pivotal trials in the United States. These studies will be critical in determining how we can expand options for patients with complex mitral valve disease.
Overall, I think the next breakthroughs will come from expanding indications and refining patient selection—using imaging, stronger clinical trial data, and continued device innovation to better match the right therapy to the right patient.
Bonus Question: What’s the most rewarding part of your work?
One of the things I love most about structural intervention—and what makes me excited to come to work every day—is that we can often offer options to patients when it feels like no other options exist. Even when there isn’t an approved therapy available, we sometimes pursue compassionate or emergency use pathways through the FDA when we believe a device could meaningfully help a patient.
One case that stands out involved a woman in her early 40s with a left ventricular assist device (LVAD) who developed severe LVAD-associated aortic regurgitation. She had been evaluated at multiple institutions for heart transplantation but was declined because she was highly sensitized from prior pregnancies. When she came to Columbia, our transplant team reached the same conclusion—transplant was not an option. So we asked: Is there something we can do about her aortic regurgitation?
She was too sick to enroll in an ongoing registry trial for a transcatheter AR device. At the time, she was on ECMO—essentially a form of heart-lung bypass that temporarily supports circulation when the heart and lungs cannot function adequately—and was critically ill. We applied to the FDA for emergency use authorization of JenaValve (a transcatheter valve replacement device for aortic regurgitation), and it was granted.
Just days before we received approval, she became a grandmother. Her goal, which she told us repeatedly, was simply to leave the hospital and meet her granddaughter.
There was real uncertainty about whether she would survive the hospitalization. But just 15 days after we implanted the valve, she was discharged home. When I saw her in clinic for follow-up, she looked remarkably well—she was even back at work. Watching her show us pictures of her granddaughter was an unforgettable moment.
That’s when I thought to myself, this is why I chose this profession.