Exercise in Specific Diseases: Coronary Artery Disease

Abstract

Coronary artery disease (CAD) is a progressive disease, typically starting early in life. CAD is strongly associated with cardiovascular morbidity and mortality. Regular physical activity (PA) has positive effects on multiple risk factors for CAD, while high-intensity PA may act as a trigger for sudden cardiac death, especially in susceptible individuals with an underlying cardiovascular abnormality. Therefore, recommendations for cardiovascular evaluation of older individuals aiming to participate in leisure-time or competitive sports, as well as for those with risk factors for or with established CAD, has been established. If athletes with an increased risk profile for CAD show a normal, truly maximal exercise test, they are not restricted from any competitive sport. Patient-athletes with clinically proven CAD and considered to be at low-risk for cardiac events may be selectively advised to participate in competitive sports but restrictions may apply on an individual basis for certain sports with the highest CV demand (such as extreme power and endurance disciplines) and in older athletes, having a higher risk. Patient-athletes with clinically proven CAD, defined as high risk, should receive appropriate management and be restricted from competitive sport. In patient-athletes with CAD and significant ischemia during exercise, as in all patients, anti-ischemic therapy needs to be optimized. In case of inducible ischemia, revascularization is strongly suggested. Athletes considered as “low-risk” for cardiac events post-MI and/or post-PCI are recommended a minimum of 3 months structured and progressive rehabilitation before assuming/resuming participation in competitive sports. Periodical, at least annual follow-ups of athletes with CAD are recommended, including risk factor management by lifestyle and medications, according to guidelines. Any symptoms should be evaluated, and repeated exercise-testing could be used, for risk stratification and/or modified exercise prescription.

Case Presentations

1.1 Case 1

Glenn is a 63-year old man, formerly manual worker but these days mostly office work. He seeks medical advice since he has entered into a betting contest with his son: Glenn has pledged to enter, and finish, a local 21 km half marathon race next spring. He refers to himself as interested in sports, with an active interest in sports, in particular soccer. He also played in a national low-level league in his youth. Before starting practice for the race, his wife has insisted on a medical check-up and you agree to see him.

Glenn is modestly overweight with a BMI of 29.5, waist circumference is 105 cm, sitting blood pressure is 160/90, LDL-cholesterol of 3.2 mmol/l (123 mg/dl), total cholesterol is 6.1 mmol/l (235 mg/dl), fasting glucose is at the upper limit of normal, ECG at rest shows normal sinus rhythm without ST-changes. Glenn smoked for about 10 years but stopped at 30 years of age. His wife complains that he snores a lot and for this reason they do not share the same bedroom anymore. He has no symptoms on exercise, his two older brothers are healthy, his father suffered from stroke at 72 years of age and his mother is healthy at 91. Upon questioning, it becomes evident that he has done little exercise during at least the last 10–15 years.

So what do we need to consider?

• What is he intending to do? 21 km half marathon, which is a substantial effort

• What is his level of fitness? We don’t really know but probably quite low.

• What are his risk factors and his 10-year risk? According to the SCORE diagram his risk is about 10% for fatal CVD within the next 10 years, thus he is not in a low-risk category.

1.1.1 Questions

• 1. Do we need additional workup?

• 2. Do we need to do more?

• 3. What would our advice be to Glenn?

1.1.2 Answers

• 1. Yes, a truly maximal exercise test should be performed. This was done and was completely normal; he reached a maximum load of 155 W (slightly below average for age/sex/weight), maximum heart rate of 158, no chest pain, no arrhythmias, adequate evolution of blood pressure, no ST-changes.

• 2. We need to address his risk factors i.e. re-check his blood pressure, give dietary advice for cholesterol, advice on weight loss. Given the normal exercise test, no further evaluation is required.

• 3. He needs to start regular exercise, should start on a modest level since his fitness is also modest. If he can successfully train regularly there is no reason to prohibit him from entering the 21 km race, in the coming spring.

1.2 Case 2

Björn is a 46-year-old man, never smoked, regular physical activity, in particular greatly into cycling. He frequently participates in competitive bicycle races. When doing a 120 km 1-day race in the French alps, he developed chest pain during a long climb. He managed to finish the race but then sought medical attention. An ECG showed inferior ST-depression and troponin was elevated. A coronary angiogram revealed a subtotal occlusion of the proximal right coronary artery, due to a thrombus at the site of a ruptured plaque. Residual stenosis was less than 50% and no angioplasty was therefore done. He was given a statin, ACE inhibitor, dual antiplatelet treatment and discharged from hospital. He comes to see you after 4 weeks, is about to return to work full time and is anxious to go back to training.

At this visit he is in good general condition, reports no chest pain, his blood pressure is 120/70 mmHg, LDL cholesterol is 1.9 mmol/l (73 mg/dl), glucose normal, BMI 24, ECG shows sinus rhythm, 48/min, inferiorly negative T-waves.

So what do we need to consider?

• He is a patient with stable coronary artery disease, survived an MI, and his risk factors are under control.

• What does he intend to do? He wants to go back to competitive cycling on a high to extreme level of effort.

• What is his level of fitness? Probably quite good although he hasn’t been training for the last month.

• What are his risk factors? He has a 50% residual stenosis, is free from angina, has no palpitations, and his risk factors are rather well controlled.

1.2.1 Questions

• 1. Do we need additional workup?

• 2. What would your advice be to Björn?

1.2.2 Answers

• 1. We need to know how his left ventricular function is and how he performs on a maximum exercise test. One may also consider adding an isotope to the exercise test or re-do the angiogram. An echocardiogram was done at the visit, which showed slight inferior hypokinesia, overall good left ventricular function with an EF of 55%, normal valvular function. A maximum exercise test was done the following day, showing good exercise capacity with a maximum load of 250 W, maximum heart rate of 172/min, no signs of ischemia, no arrhythmias and no symptoms.

• 2. He is now free to go back to training and may go back to competitive cycling but has to understand that as a MI survivor his risk of further cardiac events including cardiac death will be increased both at rest and during exercise.