BiVACOR

Total Artificial Heart

Andrew Kuzemczak
March 18, 2025

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Hi friend,

Welcome back to Future Human! I hope you all enjoyed last week’s edition on Soliddd and my interview with Neal Weinstock. I have two more founder interviews I am confirming in the coming weeks, so look out for more deep dives informed by direct conversation. Before that though, we must crush edition #6!

As I mentioned last week, I am going to test having an ad on this letter now that we have published five editions. I invite you all to click on the Hubspot link above and explore. If enough of you click, I may be granted another day to exist in Manhattan.

Jokes aside, I appreciate your support and understanding with this ad test. Just a fun experiment to pay for this week’s carton of eggs.

Separately, I have also been contacted by two medical practices with open positions they’d like to list via the newsletter. I will not crowd this work with anymore than one sponsor, do not worry. It takes me 10+ hours to research and write each edition, so I am protective. I will consider, however, building an associated Future Human job board. If you have a company, startup, or practice that wants to post their job opportunities, reply to this newsletter or DM me on LinkedIn. Your job posting will reach a small but highly filtered audience of medical and graduate students, physicians, healthcare investors, engineers, and business executives.

Alright, with that, let’s dive in.

We launched Future Human 5 weeks ago with Cairdac, the infinite energy pacemaker. I analogized then that if we had a dying car engine, perhaps a new battery (read: pacemaker) could help. For this week, however, we will take it to a new extreme. With that, I ask you:

When your engine (heart) is completely failing, and the availability of a replacement is limited with a waitlist, would you stop driving or explore the newest option never before seen?

The Story

How do you hide $100 from a cardiothoracic (CT) surgeon?

Tape it to their kid.

Haha 😢

That was originally a joke about neurosurgeons, but the message still applies. CT surgeons are ridiculously busy and classically have little time for anything outside the OR. Some, however, defy this stereotype.

Dr. William “Billy” E. Cohn and Dr. O.H. Frazier are staff cardiothoracic surgeons at the Texas Heart Institute (THI). Dr. Cohn is the Executive Director of the Center for Device Innovation at The Texas Medical Center and Dr. Frazier is the Co-Director of the Center for Preclinical Surgical and Interventional Research at THI. In 2008, together with Daniel Timms, PhD, they founded BiVACOR — a startup on a mission to develop the most advanced total artificial heart.

I have a soft spot for this story. Daniel Timms combined his skills from watching his plumber father work with his concern for his father’s heart health to research next-gen heart pumps as a graduate student. If all goes well, much luck is granted, and I become 100x smarter, I will bring together skills from watching my relatives fix and rebuild engines to tackle the heart disease that has similarly ailed my family. I digress.

“This device didn’t exist for my family, but it could be life-changing—and life-saving—for others.”

Daniel Timms, PhD

Since 2008, this dream has followed a classic hockey stick trajectory (gradual progress for years before a pivotal event skyrockets growth).¹

2008 - BiVACOR founded
2012 - BiVACOR headquarters moved to the US
November, 2023 - FDA grants the BiVACOR Total Artificial Heart (TAH) IDE approval for first-in-human early feasibility study
February, 2024 - BiVACOR receives $13 Million to support clinical trials
July, 2024 - first successful implantation of BiVACOR heart in a 57-year-old man (Baylor St. Luke’s Medical Center)
August, 2024 - second successful implantation in 34-year-old man (Duke University Hospital)
November, 2024 - third successful implantation and first done internationally with Australian patient
- 2 more patients implanted successfully (5 total)
December, 2024 - FDA authorization to expand early feasibility study to 15 patients
March, 2025 - Australian patient lasted over 100 days with TAH before finding donor heart, smashing previous BiVACOR record for bridge time (St. Vincents Hospital - Sydney, Australia)
- Patient was first to be discharged from the hospital with the BiVACOR artificial heart still implanted

Allow me to offer some clarity. The BiVACOR TAH has been in development for 20+ years. In the early 2000’s, Daniel explored the idea as a PhD student in Australia (hence the first international patient being Australian). Daniel focused on durable, rotary-based platforms to replace pulsatile pressure with continuous flow.

His research collaborations took him across Australia, into Europe, and finally to Texas, where he met Dr. Cohn and Dr. Frazier, his co-founders. The three brainstormed a device that could serve first as a bridge for patients waiting on a new donor heart for transplantation. From there, they aimed to improve the artificial heart until it could reasonably become a long term heart replacement (still in the works, but we will assess their progress).

After the 2012 move to the US, BiVACOR progressed rapidly through lab and animal trials. We now sit at the human stage which I described above. 15 new patients coming up! The progress acceleration has been marvelous.

I wrote briefly about BiVACOR on LinkedIn last summer. When I checked back last month to see they had succeeded across human trials, went international, and had a patient going on 100 days with their TAH, I knew I had to dive deeper.

The Tech

Total artificial hearts are not new. The first successful artificial heart, the Jarvik-7, was implanted in a human patient on December 2, 1982, at the University of Utah. It was designed by Robert…wait for it…Jarvik. BiVACOR is shifting the approach entirely. Current technology uses volume displacement pump designs with flexible polymer diaphragms to pump the blood. Imagine a system which reflects your diaphragm with breathing (sorry finance types, this may get confusing). As the diaphragm moves up, air (blood in this case) gets ejected. As the diaphragm moves down, it pulls air (blood) back in. Better yet, appreciate this diagram to see how things currently work.

Pulsatile Pump Mechanism

That’s fun and all, but wait until you see what BiVACOR has incubated.

The BiVACOR TAH is an electro-mechanical rotary blood pump. It is shockingly simple despite that name. It has one motor and a single magnetically levitated (’maglev’) rotor that simultaneously pumps blood to both the body and the lungs. It has one single moving part, the levitating rotor.¹

The maglev system suspends and precisely controls a single rotating disk, which acts as the pump’s impeller. This technology allows the impeller to float freely within an electromagnetic field, offering:

Reduced contact with surrounding components, preventing wear and tear
Precise blood flow control, adjusting circulation actively based on patient needs
Minimized complications such as clot formation and hemolysis (damage to red blood cells)

Allow me to explain the third advantage with some medical principles.

Virchow's Triad describes the three main factors that contribute to thrombosis (formation of clots):

Hypercoagulability (bodily state with increased clotting factors)
Stasis (slow blood flow)
Endothelial injury

In the surgical field, it is gospel that any mechanical intervention (think new heart valve or chromium hip replacement) can lead to increased clotting. Your body has no idea what this device is, so it may attack it and over compensate on the bleeding prevention. With new heart valves, regions of flow stagnation or disturbance can famously precipitate thrombus formation. One theory is that increased shear stress for the cells moving across the metal can lead to blood cell damage and platelet activation.⁴ This issue is not avoided with total artificial hearts.

With current TAHs using diaphragmatic pumps, let me ask you, what happens between each beat when the diaphragm is stationary for a fraction of a second?

Blood stagnation. Mixed with blood cell injury, we have a major clotting risk.

For those smartly wondering: Then why don’t we have a clotting issue naturally since our heart is beating and not in continuous flow?

Our red blood cells are not being damaged moving across the natural tissue compared to the new metal, so they are not leaking inflammatory and clotting factors
We do clot occasionally, and it is a problem. Traditionally in our left atrial appendage, our pulsatile flow leads to some stagnant blood in this corner of the heart which can clot. When someone has an arrhythmia, the abnormal beat can dislodge this clot and lead to a stroke

So BiVACOR has a magnetically levitating rotor spinning constantly to keep blood moving smoothly, avoiding stagnant flow and by extension dangerous clotting post implantation.

BiVACOR TAH

BiVACOR has developed a small yet powerful system. Their TAH is capable of providing flow over 12 L/min (at rest cardiac output is about 5 L/min). The small size also makes the BiVACOR more suitable for women and children in the future, which have notoriously been left behind in cardiovascular care. With a small external controller and a rechargeable battery system, the BiVACOR will offer patients freedom and mobility as they await their donor heart.

You may notice that, although it is called a Total Artificial Heart, it is currently used as a bridge for patients awaiting a donor heart match. It buys them time. This is a critical use case, but it is also key to highlight BiVACOR’s aim to become a potential long term replacement for those with late stage heart failure. They were even recognized among TIME’s Best Inventions of 2024 given their heart’s potential to work indefinitely, possibly eliminating the need for live-organ transplants altogether.³

Picture a day where we do not need to worry about donor matching and organ waitlists. A mechanical heart with all of the functionality and longevity of a human-derived option.

The truest Future Human.

The Market

As I said, artificial heart transplants are currently used as a bridge for patients awaiting a matching donor heart. The tech supports them since their original heart is failing rapidly.

The heart failure market is large and growing rapidly thanks to an aging and weight gaining population. In 2023, just the top seven heart failure markets alone (US, EU4, UK, and Japan) represented a $6.6 billion opportunity. Those seven are growing 9.8% each year and will hit $18.5 billion in 2034.¹⁰

Now to be fair, not all heart failure patients need transplant, so lets focus a little deeper on just those that could use an artificial heart.

The global artificial heart market is valued at anywhere from $2.8-3.1 billion growing between 11-12% annually.⁸^,⁹ Small but growing quicker as technology advances, with no small part of that thanks to BiVACOR.

BiVACOR, however, is not the only player. There are few, but they are critical to pay a visit.

SynCardia is undeniably the market leader. Why you ask?

Well they literally have the only FDA-approved TAH. Founded in 2001, they have crafted a proven track-record. They also boast the record for the longest time on a TAH. Nurullah Balik, a former Turkish professional soccer player, received the SynCardia TAH in August of 2012. He waited 4.6 years on the TAH before finding a donor match.⁵

May seem tough to beat, but not if you are two determined Texans and a genius Australian engineer.

SynCardia’s device is much larger, requiring a major external power source. It uses the antiquated pneumatic, pulsatile pump. It also has limited long-term use with no company statements (at least none that I could find) confirming any ambitions to become the permanent transplant standard of care. It is blessed with the only FDA approval, offering it perfect monopolistic conditions, but hopefully not for long.

BiVACOR must also watch out for Carmat’s Aeson TAH. Although it uses a pulsatile system, which we know is more prone to clotting, it has a biological component (bovine heart tissue) to reduce metal/plastic exposure and cell damage. It is approved in Europe and now undergoing US trials.⁶

Finally, among our academic powerhouses, we have NYU playing with pigs.

Seriously, a team at NYU Langone Health successfully transplanted two genetically engineered pig hearts into recently deceased humans in 2022. The deceased body donors were maintained on ventilator support. Incredibly, no signs of early rejection were observed in either organ. Post-transplant medications were kept standard and mechanical support was removed to reveal normal heart function.⁷

It’s no easy task to develop a total artificial heart, but BiVACOR is in a favorable position to come out on top. They boast:

Improved durability: no mechanical wear with a levitating system
Reduced clotting: continuous blood flow mitigating thrombosis
Adaptability: left and right circulation monitoring to meet needs
Compact size: suitable for women and children
Permanent use potential: company aiming to move beyond the bridge-to-transport use case

“I don’t always bet on total artificial hearts, but when I do, I bet BiVACOR.”

Andrew Kuzemczak, M1

The Sick

Whether you are in medicine or not, you have certainly heard of the infamously long organ transplant list. Whether it is for a kidney, liver, or heart, physicians and care teams are left to use a host of clinical grading scales to judge where someone should fall on each list. It is a sad but necessary duty, and it is not getting easier.

The wait time for a heart transplant can range from days to years, depending on severity of illness, blood type, and immune system status. Patients with more severe critical conditions are prioritized, but not if they are so severe to not meet the life expectancy minimums post-transplant. Patients must have a matching blood type with the donor for compatibility sake (recall: your body attacks what it does not recognize). Recipients must also have an acceptably low antibody level to prevent rejection and their body size must work with the donor’s heart.

Needless to say, there are countless hoops to jump through just to qualify. Then, there are not enough hearts to go around in the first place.

I spent a while diving into the International Society for Heart and Lung Transplantation (ISHLT) archives, and wow was it an equally depressing and motivating experience.¹¹ Bear with me:

More than 5 million Americans are currently living with heart failure
250,000 Americans have advanced heart failure and might benefit from a transplant
3,000+ Americans are on the waiting list for a heart transplant on any given day
2,000-2,200 donor hearts are made available each year in the US
About 5,000 heart transplants occur worldwide each year, but a staggering 50,000 people are in need of a donor heart

Even with this, getting a heart transplant is not just a numbers game, it is also a qualification challenge.¹²

You can be delayed by active cancer, uncontrolled diabetes, obesity, or current alcohol or drug abuse
Physical/Lab tests
- Dual energy X-ray absorptiometry (DEXA) scan to check bone density
- Glomerular filtration rate (GFR) testing to measure kidney function
- Hemoglobin A1C testing to check for diabetes
- Imaging (X-rays, ultrasounds, and CT) to evaluate your organs and blood vessels
- Pulmonary function test to measure lung capabilities

Sufficiently sad? Okay, now let me cheer you up with some techno-optimism.

Heart transplants provide a median survival rate of 12-13 years. A patient receives a comprehensive heart failure team made up of cardiologists, heart failure nurses, cardiac pharmacists, cardiac rehab specialists, psychologists, and many more.¹³ This path to transplant is long and complex, but when successful, offers over a decade back for each patient. This makes BiVACOR and its TAH that much more significant.

Even if the technology remains a bridge for years to come, and pauses on venturing into long term territory, it is still saving thousands of lives who await a donor heart. From there, when it eventually proves durable enough (thanks to maglev) with fewer clotting drawbacks (also thanks to maglev) to become a viable long term option, we will witness even more lives saved.

For some patients, the delay is in the availability of donor hearts (hence the need for a bridge). For others, it is in their own qualification for a transplant. With so many criteria, some patients have too severe of diabetes or a history of severe alcoholism that denies them a new heart. If BiVACOR’s tech scales as planned, there will not be a shortage denying these patients a decade more of life. One day, hopefully soon, the question will not be if you qualify or if a perfect donor exists. It will instead be how soon you can decide between a BiVACOR robotic TAH or perhaps an NYU farm heart.

The Economy

As I said earlier, not all who experience heart failure require a transplant. With that said, heart failure is a sufficiently broad first view to take in our economics adventure.

The American Heart Association estimated over a decade ago that the cost attributable to heart failure care is $3,600 in direct cost and $1,700 in indirect costs per patient per year. By 2030, US heart failure costs are expected to be at least $70 billion per year ($244 per every US adult) with total cost of caring for patients with heart failure reaching $160 billion. These are all just numbers in the ether, so for context, the current heart failure expenditure is 2-4% of our national healthcare costs.¹⁵

Why is it so high? The most significant burden results from hospitalization and re-hospitalization. Actually 75-80% of direct costs are attributed to that alone. Our nation one day will not be able to handle it with the aging population. Heart failure is the second most common inpatient diagnosis billed to Medicare. It also has among the highest 30-day readmission rates.

Now, this transition back to the total artificial heart may be a little bumpy, so hold on…

Advanced heart failure can be managed with therapeutics, devices, lifestyle change, and a host of other options. The question becomes which is most effective at adding years of life back, and at what cost? In a 2022 systematic review evaluating the economics of heart failure in the US, the researchers noted mixed findings regarding the economic benefit of mechanical circulatory support, but one thing was clear. With each newer device, the cost per quality adjusted life-year (QALY) gained was falling drastically. One analysis even found that the most profound drop in cost per adjusted life-year was when devices advanced from axial flow (think boat propeller) to centrifugal flow (what BiVACOR offers). The cost drop was driven by a reduction in rehospitalizations, pump thrombosis, and patient stroke (just like we drew it up in our Tech section).¹⁵^,¹⁶^,¹⁷

“The decade that spanned from pulsatile LVADs to continuous flow LVADs was associated with a 50% reduction in the cost of implant hospitalization; a remarkable improvement considering acquisition cost of the device was similar. Postoperative costs primarily driven by lengths of stay in the intensive care unit and step-down units appear to have been critical for the observed cost reductions with continuous flow devices.”

Rogers et al, AHA Circulation, 2013

Some numbers for the math buffs among us:

Inflation-adjusted hospital costs were significantly lower for continuous flow patients compared to pulsatile flow patients (mean: $193,812 vs. $384,260, p < 0.001)²⁰
For the medical professionals, the clinical factors that strongly influenced hospitalization costs included bleeding, respiratory failure, and infection

Now you may notice the above quote mentions LVAD (left ventricular assist device). LVADs support the left ventricle, while TAHs replace both ventricles and valves. LVADs have been around longer, so more economic data exists which can be easily extrapolated to TAHs given their similar use case. Hope that helps clear things up.

So we have economic and medical evidence of mechanical intervention producing better results than medical options (therapeutics). We find continuous flow superior financially and medically to pulsatile options, which remains the industry standard. And we have a company slapping it all together in its early stages.

BiVACOR finds itself in a promising position hitting all the characteristics data tells us will produce a successful and life saving TAH moving forward.

Truly magnificent.

My Thoughts

Speak with a cardiac surgeon and they will tell you that surgery is going minimally invasive (MIS) — but not everywhere. A few areas in cardiac intervention are well protected from MIS. Think LVAD installation, heart failure, and transplantation. “Why?”, you ask.

Some operations are too invasive and complex to achieve without an open, sternotomy view. Put simply, hearts and machines cannot be swapped, either for a robotic or donor option, through laparascopic incisions anytime soon. Square pegs don’t fit in round holes like hearts don’t squeeze through 2 inch cuts.

Given all of this, BiVACOR represents the next frontier in transplantation. Like I said at the start, few innovations scream Future Human like a robotic heart, let alone a magnetically levitating rotor-based one.

In the fight against failing hearts, transplants will continue but many patients will stay waiting. With the BiVACOR TAH, we not only give them a much needed reprieve, but maybe one day allow them to get off the transplant list for good.

To more lives saved,

Andrew

I always appreciate feedback, questions, and conversation. Feel free to reach out on LinkedIn @andrewkuzemczak.