I Didn’t Know I Was Having a Heart Attack, Until My Doctor Told Me ‘Go to the Hospital Right Now’ (Exclusive)

Sisi Li, the founder of the fashion house Nells Nelson, didn’t know that a childhood bout with rheumatic fever had damaged her heart. At the end of 2023, she began experiencing health struggles that she originally thought were due to grief over losing her father, but she was actually in cardiac distress. Li continued to work, unaware that she was having a heart attack. After undergoing life-saving surgery at Northwell Lenox Hill Hospital in New York, Li has incorporated her health journey into her new collection — and will donate a portion of the proceeds from a specially designed piece to women’s heart initiatives. Below, she shares her story with PEOPLE.

It was New York Fashion Week in 2023, but I dropped everything. My father had stage 4 lung cancer, so I flew to Hong Kong to spend time with him during the final journey.

That’s when I started to feel under the weather — but it was on and off. I’d get better, and then, all of a sudden I have a headache. I thought it was just stress.

At the end of November, I was eating breakfast with my assistant before flying to Toronto. All of a sudden, I felt this jaw pain that is very strange. It’s a shooting pain, but it’s very fast. I was able to get disability help at the airport because I had a nerve injury while I was in Hong Kong. Maybe that helped me because I was in a wheelchair and I wasn’t walking too much or stressing my heart. 

I didn’t know I was having a heart attack.

When we landed in Toronto, I couldn’t walk. I couldn’t breathe. I feel nauseous. My heart was pounding. I told my assistant to go ahead, then I slowly walked to the store to meet with our customer. I thought I must have a virus or something — maybe a nasty flu or cold. But when I came back to New York, I continued to feel sick.

One doctor thought it was just a virus and gave me some over-the-counter medicine to take. I finally saw my doctor and he immediately said, “Stop everything. Let’s do the EKG.” He took one look at it and immediately said, “Go to the hospital right now. Take a taxi, a car service. Go to the hospital that you want to go to.”

I went to Northwell Lenox Hill Hospital. I had my son there, so I feel comfortable there. I know they’re good. I showed them the EKG and then immediately I’m hooked up with everything. That same day, Julia Roberts was wearing my coat in New York City. I saw the picture when I was in the ICU and started talking to different people — I was really excited.

When I was done chatting with everybody else, I said, “When can I go home?” And that’s when they told me, “No, you’re not going home, because we see fluid in your lungs.”

I had my dinner in the hospital and I was like, “You know, the salmon is really good.” And I was thinking, “Oh, you know, too bad, I won’t have it again.” I didn’t know that I was gonna stay for that long. After some tests, they decided that I needed to have open heart surgery to replace my valve, repair another valve and remove a blood clot.

I had AI to translate my medical record — it said I was critically ill and my condition was life-threatening. I was just having a heart attack and I’m working because that’s what you do as a woman. We are stronger than we think. We’re stronger than we know. That’s the problem. We just keep pushing through life. 

I was in the ICU for three weeks. I’m designing the next collection in my head, but I need to recover from this life-changing experience. It’s like aftershock, you know? Even though when I was very critical I didn’t know I was critical.

When I got out of the hospital and I arrived home, I couldn’t walk up the stairs. Then I realized, I’m really weak. Then I said, “Okay, you know what? If I have to walk up the stairs, maybe I should go to my hairdresser first, and then I come back, so I don’t have to do it twice.”

It slowly dawned on me how sick I still was.

I had always been healthy, stayed on top of my appointments, but Dr. Nirav Patel, the vice chair of cardiovascular and thoracic surgery at Northwell Lenox Hill Hospital, had asked me, “Did you have rheumatic fever when you were a kid?” I was young and remembered having a bad fever — and then, when I was a kid, if I played sports with my other friends, I would be short of breath.

He said my body learned to live with a sick heart.

All through this I never stopped sketching. My Fall 2025 collection, “New Heart, Same Beat” is inspired by my experience. When a woman wears my clothing, I want her to feel that she’s wrapped in confidence. I want her to feel pampered, and she looks ready: wherever she goes and then whatever challenges there are, she can take it.

I’ve always designed for strong, independent women — those who appreciate craftsmanship, thoughtful design and the feeling of something made with intention. That hasn’t changed, but now there’s a deeper meaning to it.

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This season, you’ll see it in my collarless tailoring — a soft drape around the neck, structured yet fluid. It’s about confidence and ease, about feeling ready for whatever’s ahead. After fighting for my life and coming back stronger, this collection is deeply personal. Every piece is designed to move with you, offering both comfort and quiet power.

I also created a special red accessory in support of women’s heart health. Red is the symbol of heart awareness, but instead of a full garment, I designed a double shirt-collar scarf and matching cuffs —taking inspiration from the men’s dickey once worn under jackets. This women’s version, made of silk, can be styled under a blazer or wrapped like a scarf. A portion of proceeds will support women’s heart health initiatives.

I want people to see that reinvention is always possible. No matter what happens, no matter how hard the setback — you can come back stronger, with more purpose. I just was in Italy for two and a half months by myself. I drove 7000 kilometers to make this collection. But I also see my cardiologist, and I take medication.

Women also can do so many things at the same time. We are multitaskers, right? But sometimes we’re so busy, we forgot to take care of ourselves.

For women, I hope this makes them pause and think about their own health. We often put ourselves last; we power through, we ignore the signs. But heart disease is real. If I hadn’t gone to the hospital that day, I wouldn’t be here now. So if this story makes someone book that check-up, if it sparks a conversation, then that means everything to me.

Click here for more on Northwell’s women’s heart program.