Athletes & preventive care

In the News: Cardiac Screening for Adult Recreational Athletes

December 8, 2014 By Larry Creswell, MD 6 Comments

An important new study caught my eye. In last week’s British Journal of Sports Medicine, Andrea Menafoglio and her colleagues from Bellinzona, Switzerland published (epublished ahead of print) a report entitled, “Cardiovascular evaluation of middle-aged individuals engaged in high-intensity sport activities: implications for workload, yield and economic costs.”(1)

The study is important because it addresses the issue of cardiovascular screening in adult, recreational athletes, an area that’s received very little attention.

By comparison, the issue of cardiac screening for young, competitive athletes has received a great deal of attention over the past 25 years. Many prominent medical scientific organizations have issued recommendations for pre-participation screening in young athletes, including the American Heart Association (1), American College of Cardiology (ACC), American Academy of Family Practice (AAFP), American Academy of Pediatrics (AAP), American College of Sports Medicine (ACSM), American Medical Society for Sports Medicine (AMSSM), just to name some of the American organizations.

These recommendations form the basis for the widespread use of mandatory pre-participation screening in secondary schools and colleges. The goal of such screening programs is to reduce the number of fatalities from sudden cardiac problems that arise during sporting activities. The successes and pitfalls of such screening programs have been reported and the findings have engendered lively debate about what elements to include in screening programs, their effectiveness, and justification of their cost.

In this new study, the investigators report on a “real world” glimpse into cardiovascular screening in adult, recreational athletes. Their aims were to evaluate the practicality of such a screening program, to measure the prevalence of previously unrecognized cardiovascular conditions in this group, and to determine the costs associated with initial screening and follow-up evaluation of athletes with an abnormal initial evaluation.

The Study

The investigators enrolled 785 athletes, aged 35-65 years (mean, 46.8 years), who engaged in “high-intensity sports” for at least 2 hours per week. The athletes’ sports included running (in 33%) and cycling (in 24%), among others. The majority of subjects (73%) were male. The athletes were primarily “amateur” (69.7), but the group included some who competed in regional (23.7%), national (4.6%), or international competition (2.0%).

Athletes with a known history of cardiovascular disease, except for treated high blood pressure, as well as athletes who had previously undergone cardiac screening within the previous year were excluded.

Each athlete underwent a cardiac screening evaluation according to the current guidelines established by the European Association of Cardiovascular Prevention and Rehabilitation (EACPR). The evaluation was free to each athlete and included:

Thorough personal and family medical history
Physical examination
ECG
Estimation of the individual’s cardiovascular risk using the Systemic Coronary Risk Evaluation (SCORE) chart for Switzerland
Blood testing for total cholesterol and serum glucose.

The SCORE chart was used to estimate the athlete’s 10-year risk of death due to atherosclerotic heart disease based on gender, age, total cholesterol level, systolic blood pressure, and smoking status. Athletes were deemed at “high risk” if their predicted risk was >5% or if any single risk factor (eg, total cholesterol, blood pressure) was markedly abnormal. The cost of this screening evaluation was reported to be $130 per athlete, or $102,050 total.

The Findings

The screening evaluation was abnormal in 112 athletes (14.3% of the total):

5.1% due to abnormal, “pathologic” ECG findings
4.7% because of abnormal physical examination
1.6% due to a “positive” personal or family medical history
4.1% because an athlete was at “high risk” for atherosclerotic heart disease

Each of these athletes then underwent subsequent, more detailed testing to shed more light on the athlete’s cardiac circumstance and to determine if a true cardiac problem was present. These tests included, among others: echocardiogram (an ultrasound examination of the heart’s structure and function); stress test; 24-hour blood pressure monitoring; 24-hour Holter monitoring (of the ECG, continuously, to evaluate for arrhythmias); cardiac MRI; coronary angiography; and tilt testing. A total of 194 such tests were performed and these additional tests had a total cost of $54,556.

In the end, a new, previously unsuspected cardiovascular problem was identified in 22 (or 2.8% of the 785) athletes:

8 with hypertension
5 with mitral valve prolapse and at least moderate mitral regurgitation
3 with biscuspid aortic valve (2 with moderate aortic regurgitation and 1 with mild aortic stenosis)
1 with mild pulmonary valve stenosis
1 with vaso-vagal syncope
1 with Wolf-Parkinson-White syndrome
1 with hypertrophic cardiomyopathy (HCM)*
1 with significant coronary artery disease and “old” myocardial infarction*
1 with abdominal aortic aneurysm*

This group included 19 men and 3 women. Of these 22 athletes with newly diagnosed cardiac conditions, 3 were deemed ineligible to participate in their sports because of unacceptably high risk of cardiovascular events (indicated by an asterisk, above). Each of the 3 athletes who were deemed ineligible for sports activities were identified by an abnormal ECG during the initial screening.

The other 90 athletes with an abnormal initial screening evaluation were “cleared” on the basis of their subsequent testing. We might refer to these athletes as the “false-positives”–those with an abnormal initial screening evaluation, but no real cardiovascular problem.

Interestingly, no diagnosis of coronary artery disease (CAD) resulted from the 76 exercise stress tests that were performed.

The Investigators’ Conclusions

The authors reached 4 main conclusions:

The screening program was effective in identifying a small, but significant, number of athletes with significant cardiovascular conditions that required treatment or monitoring.
The screening program was effective in identifying a very small number of athletes in whom continued participation in sports activities was thought to be dangerous.
Inclusion of the ECG in the initial screening evaluation was important.
The screening program was practical and the costs were reasonable.

My Thoughts

This study provides some pertinent data to help frame our discussions about cardiovascular screening for adult, recreational athletes. The study population here appears to be typical in many regards, and I suspect the study results can reasonably be generalized to athletic populations far beyond Switzerland.

Adult, recreational athletes are not typically bound by the mandatory pre-participation cardiac screening programs that are used for young, competitive athletes. They have to make their own decisions in this regard. They must decide whether “getting checked out” is worth the expense. Athletes might have a variety of relevant questions. How likely am I to discover a previously unrecognized cardiac problem–particularly if I don’t have any symptoms? What are the chances that I could be a false-positive–with the burden of additional diagnostic testing to sort things out? What will this all cost?

Each of these questions now has an answer.

With regard to the first question, there is an approximately 3% chance of identifying a previously unrecognized, unsuspected, and presumably asymptomatic, cardiovascular condition. On t op of that, there is an approximately 4% chance of identifying a high risk profile, based on risk factors, that deserves close follow-up. And finally, there is an approximately 0.4% chance (3 athletes among 785) of identifying a serious cardiovascular condition that places an athlete at undue risk of sudden cardiac death during exercise. It’s not clear from the study whether these risks are similar for men and women.

The second question also has an answer. The chance of a false-positive, using this particular screening evaluation, was approximately 11.5% (90 athletes among 785). That is a fairly large number. Recall that each of these athletes required additional diagnostic testing–at additional cost–to establish that they didn’t actually have a problem after all.

The third question has also been answered–at least in Switzerland. The average cost of the screening program–initial evaluation plus the costs of additional testing that was needed–was $199 per athlete. The cost for the 663 athletes who had a normal screening evaluation was only $130. Obviously, the costs for the remaining 122 athletes, with an abnormal screening evaluation, and who required additional diagnostic testing, were greater. All of these costs would be much higher in the United States, I suspect, and this issue is compounded by the fact that most health insurance policies don’t cover screening evaluations such as these. For many American athletes, these expenses would be out-of-pocket.

At any rate, this new information will be helpful as athletes have discussions with their physicians about whether or not to pursue cardiac screening.

Those are my thoughts about the issue from the athlete perspective.

From the physician perspective, I think it’s important to note that all of the stress testing results were normal. These are expensive tests. We need to keep in mind that the pre-test probability of an abnormal finding in an asymptomatic population of exercisers is extraordinarily low. Perhaps, it’s best to think twice before ordering a stress test in this situation.

And finally, from the perspective of the event organizer, the prevalence data here is enlightening. Governing bodies and race directors should be aware that several percent of participating athletes will have unsuspected cardiovascular problems, including 0.4% who are at high risk of sudden cardiac death during exercise. These numbers should inform safety planning efforts. It shouldn’t be surprising that we have a small number of cardiac emergencies and even fatalities in recreational competitions involving adult athletes.

Reference:

1. Menafoglio A, Di Valentino M, Porretta AP, et al. Cardiovascular evaluation of middle-aged individuals engaged in high-intensity sport activities: implications for workload, yield and economic costs. Br J Sports Med 2014;01-6. doi:10.1136/bjsports-2014-093857.

Book Review: Cardiac Athletes

July 6, 2014 By Larry Creswell, MD 3 Comments

Hot off the press is a new book by Lars Andrews, entitled simply, Cardiac Athletes. I had a chance to read the book over the July 4th holiday weekend and I thought I’d share some details here at the blog. I enjoyed the book and recommend it highly.

Lars Andrews is the founder of Cardiac Athletes, the worldwide support community for athletes with heart disease. I’ve written previously here at the blog about the organization’s many activities. You can find them online at their website and also on Facebook. If you’re an athlete with heart disease, you’ll find an active online forum that helps athlete patients make useful connections with others in similar circumstances. On the charitable front, the organization raises money to support donation of automatic external defibrillators (AEDs) to communities in need and to support cardiac screening programs for athletes.

This new book will be good reading for a variety of folks–athletes, of course, with heart disease; healthcare workers who care for these athlete patients; and pretty much anybody who enjoys reading inspirational personal stories from athletes.

Andrew LaGerche, MBBS, PhD, a physician-scientist, himself a talented endurance athlete, and with a long professional interest in athletes and heart disease, writes a great Foreword. In the Preface, Andrews details the history and evolution of the Cardiac Athletes organization and sets the stage for the remainder of the book. The Introduction features his take on 10 repeating themes that will be found in the athlete stories: cardiac athletes are pioneers; we need sports cardiology centres; are we starting to see a post athletic epidemic?; would preschool screening be bad?, among others.

The bulk of the book is a collection of the personal stories from 17 athletes affected by heart disease. Each athlete shares his/her journey from the discovery of their problem, through its diagnosis and treatment, and the long-term consequences. In many cases, there are illustrations which bring clarity to the specific heart problem being described. This is very helpful to non-medical readers who won’t be familiar with the details. Each chapter is a rare, honest look at how these athletes approach sport in the context of heart disease. These stories are just very real.

At the end is a useful glossary of terms that will make the book more accessible and also a useful reference, or reading list.

The book is currently available in print form for $14.98 from Create Space. Proceeds from the book will go to the Cardiac Athletes Trust Fund to support the organization’s charitable activities.

In the News: Marathoners and Coronary Plaque

April 3, 2014 By Larry Creswell, MD 18 Comments

Every so often, a scientific report about runners and heart disease really captures the attention of the media. About a week ago, a report in the March/April edition of Missouri Medicine entitled “Increased Coronary Artery Plaque Volume Among Male Marathon Runners” generated quite a bit of interest and discussion. I’ve written previously here at the blog about the general issue of the “heart healthiness” of long-distance running in a post entitled “Don’t Stop Running Yet!” I still feel that way. But let’s take a look, though, at this new article about marathoners and coronary plaque.

The report is written by a large group of very credible investigators from the Minneapolis Heart Institute, Integra Group, University of Colorado, Medtronic Inc., University of Minnesota, and the Mid America Heart Institute. Included in the group of authors is Kevin Harris, MD, who authored an important 2010 report on triathlon-related fatalities, William Roberts, the Runners World “Sports Doc” and medical director of the Twin Cities Marathon, and James O’Keefe, MD, a one-time triathlete who has been an outspoken critic in recent years of excess exercise.

The investigators report on a group of 50 male participants in the Twin Cities Marathon who had run at least 1 marathon per year for 25 years in a row. The average age was 59 years. None of these subjects had any history of heart disease or any current symptoms suggestive of heart disease. The runners underwent testing that included measurement of the height and weight, blood pressure, and resting heart rate; a 12-lead EKG; and blood tests for serum lipids and creatinine. The subjects also completed a questionnaire about historical lifestyle and risk factors. Each of the athletes underwent a high-resolution coronary computed tomographic angiography (CCTA) study. A control group of 23 sedentary men were identified from a contemporaneous group who were undergoing a CCTA study for some clinically-necessary reason and also underwent the other tests just like the runners did. The subjects and controls were similar in terms of: age, resting blood pressure, height, smoking history, serum creatinine, total cholesterol, and low density lipoprotein (LDL) levels.

Coronary artery plaque “lesions” were identified in both the runners and the controls: 95 lesions in 30 of the 50 runners, and 46 lesions in 12 of the 23 controls. The total volume of plaque was greater among the runners and this was also true for the amount of calcified or non-calcified plaque, as well. There was no difference in the lesion area, lesion diameter, or lesion length between the runners and controls.

Why is this all important? Because coronary plaque is generally associated with problems like heart attack. In clinical practice, we ordinarily discover coronary plaque when we search for a cause of a patient’s heart attack. Or, in recent years, we discover the plaque when an individual undergoes a screening test like a coronary calcium scoring CT scan. And we know from studies of individuals (not necessarily runners) who’ve undergone coronary calcium scoring CT scans that those with high calcium scores, indicating plaques, there is a greater risk of future heart attack. So it’s somewhat surprising that seemingly healthy long-time runners would have more coronary plaque than the sedentary controls.

On the bright side, despite being nearly 5 years older on average than the controls, the runners had significantly lower resting heart rate, weight, and body-mass index (BMI), less hypertension (high blood pressure), less diabetes, and an increased level of high density lipoprotein (HDL), the “good” cholesterol.

All of this news isn’t really new, though. These investigators first reported their findings at the 2011 meeting of the American Heart Association. It’s just now making its way into print, and into a rather unlikely and somewhat obscure medical journal for some reason. Missouri Medicine, the journal of the Missouri State Medical Association, even sent out a press release with advance copies of the article and accompanying editorials to a wide distribution list, all to take advantage of the lead-up to this year’s Boston Marathon. All pretty sensational, really. I can’t recall anything quite like this for research that was already more than 2 years old.

Given their findings, the authors conclude that “chronic excessive high intensity exercise” is the cause for the plaque build-up in the runners. They hypothesize that the mechanism is related to metabolic or mechanical stresses placed on the heart and coronary arteries during running that may be mediated by inflammation. The authors suggest, then, that “some runners” ought to “choose shorter, less exhausting challenges” in order to avoid this problem. On the face of it, this is a neat narrative, but….

1. Although the plaque volume (the total amount of plaque) was greater in the runners than the controls, the percentage of affected individuals in the running and control groups was not significantly different. Remember that 30 out of 50 (60%) runners had plaque identified and so did 12 out of 23 (52.2%) controls. In the statistical sense, those percentages are not significantly different. In terms of the most obvious, and perhaps most important, endpoint–the number of affected individuals with coronary plaque, the prevalence of coronary plaque–the study is essentially a negative study. Negative studies are hard to get published and I suspect this is why this report was published 2+ years after the study was completed.

2. If running was the cause of the plaque build-up, then why did only 60% of the long-time runners have this problem? And why did 52.2% of the controls have this problem, assuming that they were truly sedentary? Obviously the “cause” of plaque build-up in the coronary arteries is multifactorial. The authors can’t have it both ways: running cannot be responsible in the runners yet not responsible in the controls. For the runners, the real question is: what unmeasured variables might account for the finding of coronary plaque. We simply don’t know.

3. What is the consequence of having asymptomatic coronary plaque in a long-time runner? We don’t know. The current study doesn’t address this issue and to my knowledge, no study has. I’ve certainly heard from long-time endurance athletes who’ve been found to have coronary plaque, or elevated score on a coronary calcium scoring CT scan, who ask about the significance of the finding. We obviously need studies to find out what happens to such athletes.

4. What about….other endurance sports? And women? And younger athletes? There are just many, many questions left to be answered.

So, what’s the runner to do? I would still suggest that you not stop running. There’s every reason to believe that exercise is a healthy pursuit and there’s every reason to believe that exercise leads to better longevity, even for long-time endurance athletes. But stay informed. The general issue about the possibility of too much exercise is receiving a lot of attention. More studies are sure to come. And little by little, we’ll piece together the information that will help us determine if there is some sort of “sweet spot” in terms of the amount of exercise that is most heart-healthy.

Two articles on this topic caught my eye this week. Both are good reading. Amby Burfoot, the long-time editor at Running World and winner of the 1968 Boston Marathon, wrote an online piece for his magazine entitled “Heart Risk? Marathoners Have Increased Artery Plaque.” Interestingly, Amby learned last spring that he falls into the category of long-time runners with an (asymptomatic) high coronary calcium score. The second article was by Kevin Helliker in the Wall Street Journal, entitled “Why Runners Can’t Eat Whatever They Want.”

Related Posts:

1. Don’t Stop Running Yet!

2. More on Long-term Cardiac Risk and Endurance Sport

Interesting Research Studies from the ACC ’14 Meeting

April 3, 2014 By Larry Creswell, MD 2 Comments

This year’s annual meeting of the American College of Cardiology was held in Washington, D.C. last week. I wasn’t able to attend the meeting, but the results of several studies related to sports cardiology caught my attention. Here are my Top 8:

1. Prodromal symptoms, exercise, and sudden cardiac arrest (SCA). In a study reported by Lawless CE et al., questionnaires were distributed to known survivors of SCA. Prodromal, or warning, symptoms surveyed included chest pain, shortness of breath, and evidence of arrhythmia (syncope, dizziness, palpitations). Such prodromal symptoms were present in 31% during the month preceding the SCA episode. Half of the prodromal symptoms occurred at rest and half occurred during exercise. We’ve known about the importance of recognizing exercise-related arrhythmias, but the important new finding here is the importance of arrhythmic symptoms at rest as a potential warning sign for later SCA.

2. Exercise blood pressure in Olympic athletes. Little is currently known about blood pressure during exercise for elite athletes. In a study reported by Caselli S et al., 1,140 Olympic athletes from the 2008 or 2012 Games were divided into 4 groups depending upon their sport: skill disciplines, power disciplines, mixed disciplines, or endurance disciplines. These athletes underwent a battery of cardiovascular testing that included measurement of the blood pressure during a maximal bicycle exercise test. For the entire group, the peak systolic blood pressure (SBP) and diastolic blood pressure (DBP) were 190+/-21 mm Hg and 76 +/- 7 mm Hg, respectively. Interestingly, there were no differences between athletes of the 4 sporting groups. A total of 102 athletes had either SBP or DBP above the 95th percentile for the group (220 mmHg and 85 mmHg, respectively). This new information may allow for better identification of elite caliber athletes with hypertension that should be treated.

3. Maximal heart rate in men and women. We often use the calculation of 220 minus age to give an estimate of an individual’s maximal heart rate. This number has bearing in clinical cardiology testing as well as for setting up training zones for endurance athletes. Based on the observations in more than 25,000 individuals undergoing exercise stress tests, Sydo N. et al. reported that more accurate estimates for individuals older than 40 years may come from these equations: Men, 216 minus 93% of age; Women, 200 minus 67% of age. These new equations may provide better estimates for athletes who want to establish appropriate training zones.

4. Cardiovascular health and marathon training. Zilinski JL et al. reported on a group of 45 male recreational runners who undertook a relatively short 18-week, structured training program leading up to the 2013 Boston Marathon. Each of the runners had at least one known cardiovascular risk factor at the outset. They underwent clinical evaluation, echocardiography, VO2max testing, and laboratory evaluation before and again after the training period. There were significant improvement in: peak oxygen consumption, body-mass index (BMI), serum triglyceride level, serum low density lipoprotein (LDL) level, serum total cholesterol, and one particular index of ventricular function based on echocardiography. The results suggest, perhaps not surprisingly, that marathon training may be a useful strategy for improving conventional cardiovascular risk factors.

5. Running and longevity. A couple recent studies have documented a so-called “U-shaped” relationship between the amount of running and longevity among long-time runners, where individuals with moderate amounts of running enjoyed better longevity compared to those with larger (>20 miles per week) amounts of running. These previous studies have suggested some sort of “sweet spot” with respect to healthy amounts of exercise. The reasons and potential mechanisms for this observation remain unclear, though. In a study reported by Bell AC et al., an update was provided for the ongoing MASTERS Athletic Study, a longitudinal study of runners aged 35 and older. The investigators tested the hypothesis that perhaps decreased longevity among the highest-volume runners might be due to adverse cardiovascular risk factors (eg, family history of heart disease, high blood pressure, abnormal serum lipid levels, diabetes, smoking) rather than to the amount of running. It turns out, though, that these factors did not account for the difference in mortality for the 2 groups. So the reason(s) behind the U-shaped longevity curve (if it’s not due simply to the amount of running) remain unclear.

6. Pre-participation screening. There have been several guidelines about the utility of pre-participation cardiovascular screening for athletes, including the 4th PreParticipation Physical Evaluation monograph in 2010, the 2007 American Heart Association (AHA) reparticipation screening recommendations, and the Proceedings of the 36th Bethesda Conference in 2005. In a study reported by Lawless CE et al., 190 Nebraska primary care providers (PCPs) were surveyed about their use of these guidelines in the evaluation of athletes. The percentage of PCPs who “consistently used” the guidelines were only 7.9%, 11.4%, and 3.2%, respectively. The percentage of PCPs who were unaware of the guidelines were surprisingly 73.0%, 48.0%, and 76.4%, respectively. The results suggest that the guidelines are under-utilized and the investigators recognize a potential opportunity for improved screening with better education about the available guidelines.

7. Smartphone apps and silent arrhythmias. A variety of smartphone apps related to heart rhythm monitoring have become available in recent years. In a study reported by Sawant AC et al., 103 patients being treated in an outpatient setting used a smartphone app to record their EKG and then also underwent conventional EKG recording in the doctor’s office. The smartphone app correctly identified atrial fibrillation in almost 90% of cases where the arrhythmia was silent (did not produce symptoms). This technology will undoubtedly continue to evolve and may enable recording of both silent and symptomatic arrhythmias in the outpatient setting in a much easier and less costly fashion that traditional Holter monitoring.

8. Endurance exercise and cardiac remodeling. Many different sports qualify for being “endurance” activities, but each has its own unique make-up of so-called dynamic and static exercise components. In a study reported by Wasfy MM et al., 38 long distance runners were compared to 33 rowers in terms of their cardiac structure and function. The investigators found that runners had larger left ventricular (LV) volumes but lower LV muscle wall thickness than the rowers. The function of the LV was similar for the 2 groups. It’s important to keep in mind that, as far as the heart is concerned, all endurance sports are not created equal!

We can expect more detailed reporting on these studies as they make their way into print form in a scientific journal over the next year or so. Stay tuned.

Shaun White, Snowboarder, 1986 –

January 6, 2014 By Larry Creswell, MD Leave a Comment

Shaun White is a 27 year old native of California who’s become equal parts snowboarder and pop celebrity. In addition to enjoying great success in the X Games, White is also the 2-time defending Olympic champion in the halfpipe event.

Interestingly, White was born with a congenital heart condition known as Tetralogy of Fallot (TOF). With this condition, there are 2 primary defects–a hole (septal defect) between the ventricles (the pumping chambers) and narrowing, or stenosis, of the pulmonary valve and trunk. The remaining features include hypertrophy, or thickening, of the right ventricle which must do extra work to pump blood through the narrowed pulmonary valve, and an “overriding” aorta that is shifted in location above the septal defect. This condition occurs in approximately 1 per 2,000 infants.

By report, White underwent 2 operations to repair this condition while he was an infant. Today, most children have a complete repair in a single operation that involves closing the septal defect and enlarging the opening at the pulmonary valve or replacing the valve altogether. Most patients do quite well after operation to repair TOF. Over the long term, these patients may develop problems, even years later, like arrhythmias or leakage of the pulmonary valve. For that reason, these patients need periodic monitoring indefinitely.

White is an example of the growing population of adult athletes who have some form of (often corrected) congenital heart disease. It’s really not surprising that there are elite athletes in this situation. In the specific case of corrected TOF with a good outcome, the most recent guidelines from the 36th Bethesda Conference suggest that athletes can participate fully in their sports. There will be specific guidelines regarding the safety of sports for each of the many different congenital heart conditions.

There is increasing awareness in the medical community of the importance of exercise for teenagers and adults who have congenital heart disease. Recent guidelines will help athletes and their doctors make thoughtful decisions about exercising safely.

Photo by http://www.flickr.com/photos/bfishadow/ User:bfishadow.