She used to throw a discus for a living. Now she throws a robot at the oldest problem in cardiology: how to fix a broken heart valve without ever opening the chest.
Maggie Nixon // built her own major, then her own company
Inside an operating room, a surgical robot threaded a folded heart valve through a catheter, steered it into a beating heart, and set it down inside a failing mitral valve. The patient went home a few days later, feeling better than when they arrived. Then it happened a second time. Those two procedures, announced in 2025, were the first of their kind anywhere in the world - and Maggie Nixon was the CEO who got the team there.
Capstan Medical, the Santa Cruz company she runs, is building three hard things at once: a novel replacement valve, the catheter that delivers it, and the robotic platform that does the steering. Most startups would attempt one. Nixon's team is attempting the trio, aimed squarely at mitral and tricuspid valve disease, the corners of cardiology that have resisted the minimally invasive revolution that already transformed aortic valves.
"We have a novel implant, a catheter and a robotic platform," Nixon has said. "This is not for the faint of heart." It is the rare quotable line that doubles as a literal job description.
Before the catheters and the cap tables, there was a circle of concrete and a heavy metal disc. Nixon grew up outside Chicago, a math-and-science kid who happened to be very good at throwing things hard. She was nationally ranked in high school in shot put and discus, good enough to earn a full athletic scholarship to Stanford.
She arrived pre-med. She did not stay pre-med. The summer between freshman and sophomore year, her family moved to Wisconsin, where a neighbor who worked as a perfusionist trained her for a week and then let her assist in cardiac surgery. Standing at the table, she found she cared less about the patient chart and more about the machinery keeping the patient alive.
"I was much more enticed by the products, and the technology that went into how these patients were getting served," she has said. Back at Stanford, with mentor Dennis Carter, she did the thing engineers-in-waiting do when no major fits: she built her own, a biomechanical engineering degree pointed at medical device design.
*Asked the heaviest object she still throws, she named her children, into a swimming pool.
In 2000 Nixon joined a small, strange company betting that robots belonged in operating rooms. Intuitive Surgical had around 80 employees. Her first boss was an engineer named Dan Wallace. She started designing instruments on the original cardiac team, building devices for revascularization and mitral valve repair, the exact territory she works in today.
What followed reads less like a career ladder and more like a tour of every room in the building. She led instrument design teams for roughly a decade. She moved into clinical development and helped lead the development and launch of the da Vinci Xi, spending years translating what surgeons needed into specifications engineers could build. She did a stretch in quality and regulatory, scaling product quality across multiple platforms. And in her final chapter she ran Intuitive's China operations and strategy, standing up joint ventures and engineering teams an ocean away.
It is an unusually complete education. Most medtech leaders know one face of the elephant - the engineering, or the clinical, or the regulatory, or the commercial. Nixon spent two decades touching all of them. By the time she left, she could see a problem from the bench, the bedside, the audit, and the boardroom at once.
There is a tidy symmetry to Nixon's move in 2022. She left a 22-year career at one of the most successful surgical robotics companies on Earth to rejoin the man who hired her into it. Dan Wallace, her first manager at Intuitive, had founded Capstan Medical in 2020 out of Occam Labs, a Santa Cruz incubator. He is now the company's CTO. She came on first to lead Occam, then stepped into the Capstan CEO seat in 2023.
It is a bet on a relationship as much as a technology. The two have been arguing productively about cardiac devices since the year 2000. That kind of shorthand is hard to buy and impossible to fake.
Nixon says the town pairs serious technical talent with creativity and a refusal to grind life away. The team, she jokes, rides skateboards between offices. The eclectic crowd, she argues, is a feature: diverse perspectives are exactly what hard invention needs.
Aortic valves already got their minimally invasive moment. Mitral and tricuspid valves - messier, trickier, more varied - did not. Capstan is betting a robot's precision is what finally cracks them open to catheter-based treatment.
The best solutions come from a wild variety of opinions and perspectives that you kind of consolidate into a shared vision.
We have a novel implant, a catheter and a robotic platform. This is not for the faint of heart.
We had such strong internal support for giving us this runway for the next phase of the business that we only added a single investor into the mix for this round.
I was much more enticed by the products, and the technology that went into how these patients were getting served.
In December 2024 Capstan closed a $110 million Series C, led by Eclipse with participation from Intuitive Ventures, Yu Galaxy, and a single newcomer, Gideon Strategic Partners. The round pushed total funding past $150 million. Nixon led the raise, and the detail she is proudest of is how few people she had to let in.
The capital buys runway toward the milestones that matter: bringing a second-generation structural heart robotics system online, starting a pivotal mitral trial, and eventually an FDA submission. The first-in-human procedures in 2025 were proof the concept survives contact with a real patient. The next few years are about proving it survives contact with many.
Nationally ranked in high school in both shot put and discus before the scholarship to Stanford.
No major fit her interest in medical device design, so she designed one with mentor Dennis Carter.
Her first boss at Intuitive, Dan Wallace, is now Capstan's founder and CTO. They reunited after 22 years.
Favorite fruit: oranges. Favorite pet: dogs. Self-reported outdoor enthusiast.
Capstan was hatched inside Occam Labs, the Santa Cruz incubator Nixon briefly led first.
2801 Mission St, Santa Cruz - skateboard commuting optional but encouraged.
Nixon's longer view is about making robotic, minimally invasive valve replacement ordinary - the kind of procedure patients no longer have to dread. She talks about AI reading preoperative images to plan the intervention, automating the robot's positioning during surgery, and stitching imaging, planning, and controls together so outcomes stop depending on which hands are at the table.
It is an ambitious map, drawn by someone who has watched a surgical robot grow from a punchline into a standard of care once before. She is betting she can help do it again, this time inside the beating heart.
This is not for the faint of heart.