While on vacation with his wife last year, Peter Sunwoo heard about a healthy acquaintance who had a heart attack at the age of 39. He and a friend had just turned 40, so they decided to get their hearts checked — just in case.
Sunwoo’s doctor’s appointment led to the early discovery of five extremely clogged arteries, and he underwent surgery to repair them before they caused a heart attack. His doctors couldn’t pinpoint a specific cause for the blockages, and Sunwoo had no risk factors, so they speculated it was probably genetic.
“Luckily, I just found out by accident,” Sunwoo, 41, of Brooklyn told TODAY.com. “I’m an extremely unlucky person to even have this genetic thing but at the same time it is met with great luck because my heart is in a fully functional state.”
An investigation uncovers an unknown issue
Whenever Sunwoo ran most of his life, he would feel tightness in his chest. He thought running should feel uncomfortable.
“I always thought that when you ran you felt a tightness in your chest – that was always normal for me. I never thought, ‘Oh, that’s a symptom,'” says Sunwoo. “I rode my bike or swam a lot. … Running wasn’t my thing.”
Then, on a recent cruise with his wife and friends, Sunwoo and his friend suggested that they should have a heart health check-up, especially since the acquaintance who was having the heart attack appeared healthy and fit.
When Sunwoo did his cardiac stress test, some abnormalities were found. Doctors recommended he undergo a CT scan, which showed high levels of calcium. According to the American Heart Association, a calcium score tells doctors how much calcium is in the arteries. The higher the value, the more severe the blockage. A cardiologist confirmed the CT findings and located five blocked arteries.

“Most people find out (of clogged arteries) after a heart attack,” says Sunwoo.
He says the severity of his blockages led doctors to believe there was something underlying going on in his body. He ate a reasonably healthy diet and exercised regularly. He recently lost around 50 pounds before his heart problems were discovered.
“It can’t be lifestyle,” doctors say, because there’s just nothing you can do to get calcium that high,” he says. “I had no symptoms.”
Sunwoo met with Dr. John Puskas, Director of Surgical Coronary Revascularization at Mount Sinai Health System, on bypass surgery. Finding that his arteries were clogged before a heart attack meant Sunwoo’s heart muscle was still working at full capacity, and a bypass would help keep it that way.
“Just like Dr. Puskas described it, my engine is perfectly fine, but the fuel lines are clogged,” he says.
To clear the blockages, Puskas performed bypass surgery on Sunwoo.
“Blockades remain silent until they disappear”
People with heart disease are often unaware that something is wrong. Sometimes conditions such as high blood pressure or high cholesterol cause no symptoms.
“The blockades are silent until they aren’t,” Puskas tells TODAY.com. “It sounds silly, but the blocks tend to develop so slowly. They are caused by the buildup of calcium and cholesterol in the walls of the arteries that supply the heart, narrowing the pathway.”
Puskas says CT scans of the heart give doctors a good idea of artery blockages.
“Peter’s (calcium) level was 1,789. “Normal” is anything under 10, so at 1,789 he’s in the top 1% or 2% of his age,” explains Puskas. “In fact, he had some damage to his heart’s pumping function without realizing it, which is somewhat unusual.”
Doctors aren’t exactly sure why Sunwoo had such severe blockages at a young age.
“He didn’t have many other risk factors,” says Puskas. “We are a little puzzled as to why this young man developed such blockages in all the arteries in his heart. If we have nothing good to point to, we blame genes.”
Sunwoo’s chest pain while running was an early sign of heart problems, which he didn’t realize. Still, he visited the doctor before something catastrophic happened.
“He came early and he hadn’t had a major heart attack, and that’s terribly important because bypass surgery prevents another heart attack,” says Puskas. “It cannot undo a heart attack that has already happened.”
Puskas performs bypass surgery differently than many other doctors. According to the Mayo Clinic, heart bypass surgery consists of taking a blood vessel — an artery or vein — from another part of the body and connecting it to the heart so blood can flow around the blockage.
In conventional bypass surgery, a heart-lung machine (which takes over the work of the heart and lungs), a thin tube is inserted into the heart, blood is drained from the heart, and the aorta (the largest artery in the body) disconnected. and an injection of a solution high in potassium to stop the heart. However, this type of procedure carries some risks, such as: B. a stroke or cognitive decline after surgery.
Puskas does not use a heart-lung machine, nor does he insert the tube or clamp the aorta. In addition, arteries, rather than traditional veins, are his preferred blood vessel for bypass because arteries are better suited to the heart’s high-volume flow, he says.

Veins “wear out gradually,” he says, making it more likely that a young person who gets a vein bypass will need another one.
“In response to the high pressure, the veins thicken and eventually close. About half of them will be closed ten years after the operation,” says Puskas. “Those arteries will last the rest of (Sunwoo’s) life because they’re designed for a high-pressure environment. They are designed to do the job they do.”
A “Journey for Something New”
After five days in the hospital, Sunwoo returned home. The next day he walked five blocks. The day after he ran 10 blocks. The next day he ran about 3 miles. In the second week he started training on his peleton for half an hour. A month after the surgery, he was in the gym doing cardio. He couldn’t swim or lift heavy weights, but was still surprised at how he recovered.
“It was pretty painful, wasn’t it?” says Sunwoo. “The recovery was much quicker than I thought it would be. But at the same time, I’m much younger than most of the patients who do this (procedure).”
It has been more than three months since the operation, which means he is able to resume activities such as lifting or sleeping on his stomach.
“After 12 weeks, they said, ‘Your body won’t be at 100%, but you can try anything,'” he says.
He has regular check-ups by a cardiologist and will take three medications for the rest of his life: an aspirin to thin his blood, a statin to lower his cholesterol, and another to regulate his heart rate.
In the year leading up to the surgery, Sunwoo started exercising more and focusing on a healthy diet to shed some pounds from the pandemic. He eats a plant-based diet with two portions of fish per week.
Bypass surgery changed his focus a bit. He took up sailing and has planted a garden with his family, including his two children, at their home in upstate New York. Work-life balance has become really important. He has signed up for the New York City Triathlon and hikes 350 miles of the Camino de Santiago, a religious pilgrimage in Spain and Portugal.
“There’s a lot of things I’ve missed,” he says. “It’s the beginning of the journey for something new.”