Tony Taddeo and cardiac surgeon Michael Mack are not a typical pair of running buddies.

One is a 91-year-old with a new aortic heart valve, and the other is the doctor  who arranged the surgery and supervised the treatment that got the nonagenarian jogger back on the track.

“For me, running is a panacea,” said Taddeo, a retired teacher and psychologist who lives in McKinney, Texas. “It’s such a feeling of wellness, it became an addiction. And it’s part of my identity.”

So when he turned 70 and doctors told him perhaps it was time just to walk, he smiled and ignored them. He kept running: a couple of miles about five times a week and an occasional 5K, with power walking to warm up and cool down, usually along a shady path in a neighborhood park.

Combine that with yoga, Wii video games for upper-body workouts and a healthy diet – “he lives on cottage cheese and sardines,” joked his wife, Nancy – and this was no ordinary 91-year-old.

Until last November, when his body stopped cooperating.  One night Taddeo felt a crushing pain, “like a piece of concrete on my chest.” Typical for him, he ignored it, but a week later finally went to the doctor, complaining of pain and dizziness.

Tests revealed severe aortic stenosis, a narrowing of the vital heart valve, which obstructs blood flow from the heart.

“They told me it’s a disastrous situation,” he recalled. “I said, ‘You don’t understand. Only two weeks ago I was running a mile.’  They told me, ‘You’re a lot sicker than you appear to be.’ ”

The solution is generally a replacement valve, implanted with open-heart surgery. That can be debilitating and dangerous for elderly patients, with an extended recovery period, if they can withstand the procedure at all.

At The Heart Hospital Baylor Plano, Mack had a better idea. As chairman of the hospital’s research center and medical director, Cardiovascular Surgery, for the Baylor Health Care System, he has been a pioneer in a less invasive procedure to replace heart valves.

It’s called TAVR, which stands for transcatheter aortic valve replacement. Surgeons insert a catheter, with the new valve attached, into an artery through the leg or groin and guide it to the correct position, eliminating the need to break the breastbone and place the patient on a heart-lung bypass machine.

“You always want the less invasive procedure if the results are just as good,” said Mack, who has spearheaded several studies comparing TAVR outcomes and survival rates to those of traditional surgery.

The procedure was pioneered in France in 2002 and first performed in North Texas four years later, according to Mack. In 2011 the Food and Drug Administration approved TAVR for patients deemed high risk or unable to undergo surgery.

“Untreated, the outcomes (for aortic stenosis patients) are worse than most cancers,” Mack said.

The less invasive procedure currently is more expensive, Mack said, because the TAVR replacement valve, made of bovine tissue, costs more. But shorter hospital stays – usually a day or two rather than four or five – and quicker recovery times help balance the equation.

In the next few years, Mack predicts, TAVR will supplant open-heart surgery for the majority of aortic valve replacements. In the meantime, he expects a ruling from the FDA soon on approving the procedure for medium-risk patients.

While most heart patients his age would be classified high risk or inoperable, Taddeo was different. When Mack assessed Taddeo at The Heart Hospital Baylor Plano, they discovered they shared a passion for running – “and I challenged him to a 5K race after the surgery,” Taddeo said.

“It’s obvious a patient’s attitude counts for a lot,” said Mack, who ran a marathon on his 40th birthday but has kept his distances shorter since then. “He was an ideal candidate.”

But he was classified medium risk, so the cardiac surgeon needed to obtain approval for the TAVR procedure under a special research protocol. He did, and the new valve was inserted through an artery in his leg on Jan. 29. Taddeo went home the next day.

“It’s like gaining 20 years,” he said. “I didn’t even bother with cardiac rehab.”

He started running two weeks later, although he lied to his wife about doing it.

A month after the surgery, he ran a 5K “and I wasn’t even panting or breathing hard. This is a wonderful gift. Now my goal is to run a 5K when I’m 100.”

First he has a date with Mack. They met recently at the hospital to say hello, catch up and renew the challenge.

“I’ve done three or four 5Ks and I run two miles a few times a week,” Taddeo teased. “How about you?”

“I was waiting for you,” the cardiac surgeon replied with a smile. “Once it cools down, we’ll set a date.”