Are Stress Tests Necessary
for Apparently Fit Cyclists?

 

In RBR newsletter issue No. 70, we looked into the warning signs of heart problems, a topic resulting from the death of famed physiologist Ed Burke, Ph.D., who suffered a fatal heart attack while riding.

We concluded the discussion with a statement by Andy Pruitt, Ed.D., director of the Boulder (CO) Center for Sports Medicine and author of Andy Pruitt's Medical Guide for Cyclists. He also was a close friend of Ed Burke.

"My philosophy has been that anyone over 45 who exercises intensely should have a 12-lead EKG, max stress test every other year, and more often if there is any history of heart disease," Pruitt said. "Personally, I've had three stress tests in the last six years. Had Ed been on that test schedule, he most likely would still be with us."

This prompted a strong counterpoint, and then we invited Pruitt to respond.

 

Counterpoint by Daniel Taffe, PA-c

I was shocked and saddened to hear of Ed Burke's death on the bicycle and had the same initial question as many: How could someone so closely linked to the upper echelons of cycling science have a fatal heart attack while riding? Thank you for publishing additional information. As you point out, Mr. Burke had multiple risk factors for heart disease (family history, age, high blood pressure, high cholesterol) and had warning signs (decreased exercise tolerance, chest pain relieved with rest).

I must, however, disagree with Andy Pruitt's recommendation that all hard-riding cyclists over 45 get an exercise treadmill test every two years.

I would argue that for most cyclists this is unneeded, and in an era of runaway health care inflation is an irresponsible use of health care dollars.

In a standard exercise treadmill test, patients run on a treadmill following a specific schedule of pace and gradient increases (called the Bruce Protocol.) The test does not detect coronary artery disease, but instead uses surrogate information to predict the likelihood of coronary disease (which subsequently may be found by cardiac catheterization). The surrogate information includes EKG changes during exercise, maximal heart rate achieved, maximal energy expenditure (METs), and subjective symptoms (chest pain/pressure, jaw pain, etc.).

The test is generally halted once a person achieves their maximal predicted heart rate (220 minus age). Information from the test is then used to predict the likelihood of a person having coronary artery disease. If the test suggests he does, a catheterization is used to determine if, in fact, disease exists. However, treadmill tests sometimes suggest that a person has coronary disease when they don't, and they sometimes fail to detect coronary disease.

As such, a 45-year-old cyclist who goes for a ride in hills and pushes his pulse into the 170s without chest pain, etc. is doing a maximal exercise test on every ride and can obtain nearly all the information obtained on the treadmill. A cyclist who has few risk factors for coronary disease and can exercise to a high level of exertion without any symptoms of ischemia is unlikely to have coronary artery disease.

Cyclists are, on the whole, a relatively low-risk population in terms of coronary artery disease because we are less obese, more physically fit, have lower blood pressure and cholesterol, and smoke less than our non-cycling counterparts. In this population, a blanket approach of testing everyone would result in countless normal tests with very few discoveries of undetected heart disease. Furthermore, because of the low pretest probability of heart disease in this population, many "positives" would be false positives, but would require a cardiac catheterization which carries increased cost and risk to the individual.

Cyclists, listen to your body for the symptoms of heart problems. See your health care provider for a physical at regular, age-appropriate intervals. Make sure you discuss your exercise habits, any symptoms you have while riding, and find out your overall risk of heart disease (there are algorithms to predict the likelihood of a heart attack in the next 10 years).

Your provider should use the information obtained at your physical to determine whether a treadmill stress test is appropriate for you.

 

Response from Andy Pruitt, Ed.D.

In 1997, my friend Christian Norman died at the age of 41 from a massive heart attack. In his youth, he was a world-class Nordic skier, a member of the King's Guard in Norway, an all-America athlete at the University of Colorado, and a successful marathon skier on the pro circuit well into his 30s.

In the fall of 1997, Christian was having some symptoms that made him uncomfortable while exercising. He did have a crash that bruised some ribs which, of course, confused things. He went to his family doctor, where he was told he had hyperlipidemia (high cholesterol). He underwent a resting electrocardiogram (EKG), which was normal.

Within the week, Christian went skiing with his friend and training partner Davis Phinney. During the ski, he said he did not feel well and was going to sit down and rest. He died while resting. I truly believe that if he had gone to a human performance laboratory or cardiologist's office to have a 12-lead EKG while exercising, his disease would have been seen and lifesaving measures could have been taken.

Since Christian's death, I have named the Boulder Center for Sports Medicine's Sport and Health Science Laboratory after him, and I can relate at least two lifesaving athletic stress tests.

Both individuals were having classic cardiac symptoms while exercising and had undergone resting EKG at the hands of their chosen physicians and were deemed healthy. But in our laboratory under the stress of their endurance sports of choice, the tests were shut down midway because of significant cardiac findings on the EKG. Both underwent invasive cardiac procedures and are still alive and exercising today.

Most recently, we lost our friend and colleague Dr. Ed Burke to a sudden death while on a regular noontime ride. He had been experiencing fatigue, decreased performance and on one ride several weeks before his death, he felt "severe indigestion." Like the death of running expert Jim Fixx two decades before, Ed's death shocked us. Out of all people, they should have understood what was going on.

I would admit that the prevalence of exercise-induced sudden death is extremely low (1 in 15,000 in casual athletes, and 1 in 50,000 in highly trained athletes). However, if it is you or your loved one, it is a very big deal, no question!

So what kind of screening should be routine? There are no universal standards for screening athletes. There is an Italian law that requires athletes to be screened annually and include EKG. The Italian prevalence of sudden athletic death is extremely low.

The American Heart Association suggests that athletes who participate in strenuous sports undergo cardiovascular screening every 5 years under the age of 45 and every 2-3 years over the age of 45. It also suggests supervised stress tests with 12-lead EKG for men over 45 and women over 50, if they have a history or symptoms of early heart disease.

What is the cost of this close scrutiny of one's cardiac health? Over the age of 40, an annual visit to your doctor or other qualified health care professional is probably covered by insurance. At that visit, a physical exam is carried out, a complete family history is taken, your blood pressure is taken in several postures, your cholesterol is measured and, if necessary, a resting EKG is done.

A visit to a cardiologist, which might include a treadmill stress test, can be expensive, costing $500 to $800. A trip to a human performance laboratory found at sports medicine centers and universities across the country can cost around $150 for a sport-specific max VO2, lactate threshold and 12-lead EKG. This is a great value considering what we spend on sports equipment.

I would note that the screening should not promote a false sense of security or sense of invincibility. It is part of an ongoing cardiac health program including monitoring your blood pressure, your cholesterol, your diet, your stress and your exercise.

My personal recommendation is that individuals who exercise strenuously and are over the age of 45 should see their physician annually for a physical exam including checks on cholesterol and blood pressure. Every two years, they should undergo a max stress test with 12-lead EKG. This stress test should be carried out using your vigorous sport, if possible.

This is your best assurance that you will not leave this Earth early and will enjoy an active athletic lifestyle until death do you part. Ride fast, ride for life.

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