Sister Thomas spent a lifetime teaching and serving others at the Dominican Convent in New York City. Still active at 91, she spends her days on the computer and tutoring young people. To her nieces, she is like a second mother.
"You just loved being around her. She's a warm person. But a few months ago, her health was starting to fail," her niece Marie Marzec said.
About six months ago, doctors had told Sister Thomas that her heart was faltering.
"That's what caused me to be exhausted and not able to sleep," she said.
Doctors diagnosed her with aortic stenosis. A heart valve with stenosis is narrowed and blocks blood flow.
Dr. Martin Leon, a heart specialist at Columbia Presbyterian Medical Center, said the health of a patient with aortic stenosis deteriorates very rapidly.
"When the valve doesn't open normally, pressure builds up in the heart. Patients get short of breath because the pressures in the lungs are now elevated and they accumulate fluid in the lungs. But they can also develop chest pains, lightheadedness and fainting as well," Leon said.
Leon said Sister Thomas needed a new heart valve, but that meant open-heart surgery, an operation she was likely too frail to survive. Eight years ago, her sister died from aortic stenosis and it seemed she was looking at the same fate.
"She's very dear to us and our whole family, so it was scary," Marzec said.
Experimental Procedure a Success
But there was hope in an experimental procedure that replaces heart valves in a less invasive way.
The operation involves no open-heart surgery and no daunting recuperation. A replacement heart valve is sewn into a stent. The stent is attached to a catheter, then through an artery in the leg, the catheter is carefully threaded up to the heart valve. The stent expands and the new valve unfolds and does its job.
At the end of October, Sister Thomas became one of only a few hundred people in this country to have the new procedure.
The procedure is so groundbreaking, even the most experienced doctors are excited about it.
"In my career , this is probably the biggest thing to come along since heart transplants, which is now quite a few years ago in my career," said Dr. Craig Smith, a heart specialist at Columbia Presbyterian.
One month later, Sister Thomas was back for a checkup and feeling great. In fact, she said she felt well a day after the operation.
"I could tell the difference the night after...in terms of the breathlessness," Thomas said.
A few weeks before, she couldn't take a few steps without getting out of breath; now she zips around the convent.
She is hoping to start tutoring again soon. For her family, the procedure and her recovery have been a holiday gift like no other.
"And it paid off, it paid off, her braveness. And she's helping to pave the way for other people. That's the best part," said her niece Shelley Moran.
In the clinical trials at Columbia Presbyterian, doctors are confining the heart-valve procedure to people who can't have open-chest surgery, which includes putting a patient on a heart-lung machine and involves a long recovery process.
But ABC News' medical editor Dr. Tim Johnson says that eventually the heart-valve procedure will start replacing traditional surgery.
"That means, probably, well over 100,000 people a year in this country will have this relatively simple procedure," Johnson said.
If you have questions for Columbia Presbyterian Medical Center about the heart-valve procedure you can e-mail email@example.com