Dave Brenner is no slacker – he’s completed 137 marathons in his 58 years.

Last September, he set a new goal: climbing Mount Kilimanjaro, the highest mountain in Africa and the tallest freestanding mountain on earth at 19,341 feet.

Reaching the summit will first require a 24-hour plane ride from Denver to Tanzania. From there, he would join four other hikers and about 25 guides on a seven-day journey that would start in the rain forest, navigate through heathland and alpine desert over 24 miles and top out in a volcanic moonscape.

“I’ve always been outdoorsy, and Kilimanjaro has been on my bucket list for a while,” Brenner said. “So when a friend said she was going to do it, I thought this was the time to go.”

Brenner, however, had one big complication: He had been battling coronary artery disease.

Battling coronary artery disease

Coronary artery disease is the leading cause of death in both men and women in the United States. Arteries that supply blood to heart muscles become hard and narrow due to buildup of plaque on the inner walls, making it difficult for people with the disease to pump enough blood to their hearts.

Brenner learned he had coronary disease after a heart attack in 2005. Doctors placed two stents in a main artery to help maintain blood flow. Over time, the artery became blocked and during a Georgia triathlon in 2017, Brenner became lightheaded. Thinking he was dehydrated, Brenner stopped at a house along the route. There were too many warning signs that Brenner may have been on the verge of a major cardiac event, and a call was placed to 911. At the hospital, tests revealed heart blockages and Brenner underwent bypass surgery.

He returned home to recover and joined the cardiac rehabilitation program at UCHealth Medical Center of the Rockies in Loveland.

Bouncing back with cardiac rehab

Professionally trained staff in cardiac rehab follow clinical guidelines to develop and progress a patient’s exercise prescription after a heart event. Staff members help patients set realistic goals and also provide information about coronary disease, risk factors, medications, signs and symptoms and home exercise guidelines. Participants and their significant others are encouraged to meet with a counselor for stress management and to obtain resources and support for lifestyle challenges. Patients work with a registered dietitian to set goals and address nutrition needs.

Participation in the outpatient program is important because it helps to lower hospital readmission risks, improve levels of depression and anxiety, and increases one’s chance of survival, said Suza Ault, nurse manager for UCHealth cardiopulmonary rehabilitation in northern Colorado.

“Many patients realize improved levels of confidence as a result of supervised rehab — Dave (Brenner) was one of those patients,” Ault said.

Brenner began rehab last April and has gradually increased his exercise capacity — and the treadmill’s incline — to simulate hiking. He wanted to keep training to climb four Colorado 14ers, mountains he had planned to climb before bypass surgery to prepare for his Kilimanjaro expedition in September.

Then a few weeks in, he experienced another setback. While in rehab, doctors detected atrial flutter in Brenner’s heart, a common occurrence after surgery. Atrial flutter occurs when the upper chambers of the heart beat too fast and are out of sync with rhythms in the lower chambers. Atrial flutter is not life-threatening, but if left untreated there is a higher risk for blood clots, which can be deadly, said Dr. Russell Heath, a cardiac electrophysiologist with UCHealth Heart and Vascular Clinic – Harmony Campus.

Instead of opting for a lifelong prescription of blood thinners – which come with risks of their own — Brenner instead chose a treatment called catheter ablation. Doctors use radiofrequency energy to destroy the small area of the heart tissue that is causing the rapid heartbeats, according to the AHA.

Brenner returned to rehab and after a few months, he was off blood thinners and training again for Kilimanjaro.

Back to the plan

“The whole point of doing these heart procedures is to get the patient back to their normal state of living; back to the things they want to do,” said Dr. Matthew Purvis, interventional cardiologist with UCHealth Heart and Vascular clinics in northern Colorado, and medical director of cardiac rehabilitation at MCR and UCHealth Harmony Campus in Fort Collins.

“Dave leads such an active life and puts in that effort every day. So climbing Kilimanjaro was not out of reach, though still an impressive achievement,” Purvis added.

Brenner couldn’t see his life any other way.

“My philosophy is that you only live once — but hopefully, you die much later,” he said. “Why do we do any of this? Why do we climb 14ers? Because when we get up there it is beautiful. Even with my heart issues, I have no regrets.”

September soon came and Brenner found himself on an airplane to Tanzania.

Climbing Kilimanjaro

“We got to Africa on a Saturday,” he said. “You are near sea level and go on several practice hikes where they teach you how to walk slowly. The next day, you start and go to about 8,000 feet, where you go on more hikes. Then you go up another 1,500 feet, and they keep you there for a couple days, hiking to acclimate you to the altitude. The whole time you are moving, but walking slowly.”

Moving at a slow pace helps hikers adjust to less oxygen as they climb higher and higher. Brenner compared it to how his legs feel after a hard race — almost jelly-like, but he said it affects the whole body.

“It’s much different than how I’m used to hiking,” he said. “Climbing a 14er, I’d race to the top, bring a snack and take a 20-minute break, and then get down. But here, we moved very, very slowly, taking maybe five-minute breaks.”

At 15,000 feet — higher than anything else in Africa — storm systems moved around the mountain, and hikers faced freezing temperatures. At that altitude, they rested for only four hours before making the climb to the summit.

On summit day, which started around midnight, the mountain would demand 17 hours of almost continuous hiking. The first few hours were mostly straight up, at a snail’s pace, Brenner recalled. As the sun rose and the summit became visible, Brenner kept the faith that his conditioning would allow him the opportunity to stand where only a few people have.

“I did think about if my heart would tell me if there was a problem so I could turn around and go down. But I didn’t feel anything that a regular person wouldn’t have felt,” he said, a smile formed on his face as he continued. “It was amazing to be up there.”

The guides monitored each hiker’s oxygen levels and pulse during the journey, and they spent more than three hours at the top. Their descent was similar to the ascent, with a lunch break at 15,000 feet and a rest at 12,000.

Brenner was proud that he did just as well as his fellow climbers — maybe even better.

The latest brush with mortality

Brenner made it safely home from Kilimanjaro and, a month later was running a marathon in Portland, Oregon, when his body sent him another distress call.

“I was just going along and then I felt faint,” Brenner said. “I’ve never felt faint before.”

He fell to the ground. A nurse happened to be running beside him and immediately started CPR. Medics got there within minutes and shocked him back to life.

Brenner had experienced ventricular fibrillation, the most serious type of cardiac rhythm disturbance, according to the AHA. When this happens, the heart’s electrical activity becomes disordered, and the lower chambers contract in a rapid, unsynchronized way, resulting in little or no blood being pumped by the heart.

Brenner now is recovering again. He is giving up running marathons, but he has no plan to stop seeking adventure. Brenner has returned to cardiac rehab at UCHealth and continues to build his strength and confidence.

“Although I may not compete anymore, I’ll keep training,” he said as he walked out of his cardiac rehab session.

Though he won’t compete in the big races anymore, this summer he plans to run a few smaller races: the BolderBOULDER and Vail Pass section of the Triple Bypass Bicycle Ride.

He plans to return to Portland this fall but this time, he’s opting for a half-marathon.