Coronary Artery Disease (CAD)

LEOs with No Known CAD

LEOs ≥40 years of age who are asymptomatic with no known CAD should be assessed annually for their 2-year or 10-year risks of atherosclerotic cardiovascular disease (ASCVD), defined as coronary death or nonfatal myocardial infarction, or fatal or nonfatal stroke.¹⁹ The 10-year ACC/AHA Risk Estimator Plus uses the individual’s age, sex, race, total cholesterol, HDL cholesterol, systolic blood pressure, blood pressure lowering medication use, diabetes status, and smoking status to generate a 10-year risk of ASCVD (see http://tools.acc.org/ascvd-risk-estimator/).¹⁹ Those assessed at intermediate (10 to <20% of ASCVD risk over the next 10 years) or high risk (≥20% ASCVD risk over the next 10 years) should be further evaluated using symptom-limiting EST to at least 12 METs. The 2-year risk estimator uses the same information except race is not included in the calculation. Using Tables 1a and 1b, those assessed at intermediate (2-4% of ASCVD risk over the next 2 years) or high risk (≥4% ASCVD risk over the next 2 years) should be further evaluated using EST to at least 12 METs.¹⁸

Exercise stress test (EST): EST provides valuable diagnostic, prognostic, and exercise tolerance (aerobic capacity) information.²⁴ EST should be conducted according to the American College of Cardiology/ American Heart Association (ACC/AHA) protocols.²⁵ Although EST is frequently ended when the patient reaches 90% of the target heart rate [e.g., 90% X (220 – age)], ACC/AHA recommends a symptom-limiting end point.^25,26,27 Individuals with normal EST should be retested every 1 to 3 years based on individual clinical assessment and ASCVD risk scores. Stress echocardiography increases the sensitivity and specificity of EST, but also significantly increases the cost of the test. Stress echocardiography is indicated for asymptomatic LEOs with an abnormal resting ECG (e.g., left bundle branch block), left ventricular hypertrophy, or high risk (≥20%) of ASCVD over 10 years).²⁸ Stress myocardial perfusion imaging also increases the sensitivity and specificity of EST, but also increases the costs. Stress myocardial perfusion imaging may be indicated for asymptomatic LEOs with diabetes mellitus, a strong family history of CAD, or high risk (≥20%) of ASCVD over 10 years.²⁸ Newer technology tests (e.g., coronary artery calcium scoring, computerized tomographic angiogram) are reasonable for asymptomatic LEOs at intermediate (6-10%) or moderate risk (10-20%) of ASCVD over 10 years.^24,28-32

Abnormal EST: If the LEO has an abnormal EST,^25,26 the individual should be restricted and referred for further evaluation.

Indeterminate EST: If the initial EST is interpreted as indeterminate or borderline abnormal, then cardiology consult and/or EST with imaging should be considered.^25,26

LEOs with Known CAD

Angina: Any LEO with stable or unstable angina should be provided with work restrictions and referred for further evaluation and treatment.

Post-Myocardial Infarction: The risk of a major cardiac event is greatest within the first few months after a myocardial infarction (MI). The LEO must be evaluated prior to return to duty and annually thereafter.

The return to full duty and annual evaluation should meet the following criteria^20,21,27,33:

• minimum recovery period ranging from 6 weeks to 3 months (see Table 2);
• no angina;
• normal left ventricular function defined as a normal left ventricular ejection fraction (LVEF) as measured by a gated blood pool scan, echocardiogram, or ventriculogram^(b),34;
• normal imaging EST to at least 12 METs;
• stable regimen of cardiovascular medications for the past month;
• reduction or elimination of modifiable CAD risk factors (total cholesterol, high- and low-density lipoprotein cholesterol, systolic BP, diabetes, and smoking).

Post-Percutaneous Coronary Intervention (PCI)^C: For LEOs who have undergone a PCI after sustaining an event causing myocardial damage, see section on post-myocardial infarction above. The LEO who has undergone a PCI without myocardial damage must be evaluated prior to return to duty and annually thereafter.

The return to full duty and annual evaluation should meet the following criteria^20,21,27,33:

• minimum recovery period ranging from 1 week to 3 months post-PCI (see Table 2);
• recovery of access site with no evidence of significant hematoma, pseudoaneurysm, or infection;
• no angina;
• normal left ventricular function (see definition above);
• normal imaging EST to at least 12 METs;
• stable regimen of cardiovascular medications for the past month;
• reduction or elimination of modifiable CAD risk factors (total cholesterol, high- and low-density lipoprotein cholesterol, systolic BP, diabetes, and smoking).

Post-Coronary By-pass Graft (CABG) Surgery:

The LEO who has undergone a by-pass graft surgery with or without myocardial damage must be evaluated prior to return to duty and annually thereafter.

The return to full duty and annual evaluation should meet the following criteria^20,21,27,33:

• minimum recovery period ranging from 3 to 6 months (see Table 2);
• healed surgical sites (sternum and leg);
• no angina;
• normal left ventricular function (see definition above);
  • normal imaging EST to at least 12 METs;
  • no ischemia on imaging EST that must reach at least 12 METs, conducted no less than 3 months post event (see EST section) and annually thereafter;
• stable regimen of cardiovascular medications for the past month;
• reduction or elimination of modifiable CAD risk factors (total cholesterol, high- and low-density cholesterol, systolic BP, diabetes, and smoking);
• chest X-ray for evaluation of pleural effusions (at the first evaluation only).

Coronary Artery Spasm

The LEO with treated coronary artery spasm can be returned to full duty if the following criteria are met²⁷:

• no recurrence of symptoms of coronary spasm;
• treatment with calcium channel blockers and/or long-acting nitrates (i.e., not sublingual);
• normal imaging EST to at least 12 METs;
• clearance by treating cardiologist to participate in high exertion activities.

Coronary artery spasm is associated with increased risk of life-threatening arrhythmias and sudden cardiac death.³⁵ The condition is diagnosed by the absence of identifiable atherosclerotic lesions by provocation studies, typically during dobutamine or adenosine EST.³⁶ When diagnosed and associated with symptoms of cardiac ischemia or life-threatening arrhythmias, the LEO should be restricted. LEOs with coronary spasm and treated with an implantable cardioverter defibrillator (ICD) should be restricted according to section on ICDs.

Coronary Artery Dissection

The LEO Task Force does not recommend screening for this rare condition, but if diagnosed, the LEO should be restricted due to its association with increased risk of incapacitating sudden cardiac events.³⁷ Spontaneous coronary artery dissection refers to dissection of the coronary arteries without underlying atherosclerosis.³⁸ Spontaneous coronary artery dissection is associated with late pregnancy and the peripartum state, female hormonal therapy, Marfan syndrome, exercise, chest trauma, PCI, and fibromuscular dysplasia.^37,38 It is a rare cause of cardiac events, but should be considered in any young person who develops an acute cardiac syndrome during vigorous exercise or after chest trauma.

Myocardial Bridging

The LEO Task Force does not recommend screening for this condition, but if diagnosed, the LEO should be restricted until the following criteria are met:

• surgical resection of the bridge or stenting when recommended by the treating physician;
• recovery period of at least 6 months after surgical resection or stenting²⁷;
• normal imaging EST to at least 12 METs.

Myocardial bridging is diagnosed when a portion of a major epicardial coronary artery is completely covered by myocardium. Myocardial bridging is commonly observed by angiography as coronary artery compression during systole. It is usually asymptomatic and of no clinical consequence. However, it has been associated with exercise-induced ischemia and exercise-related acute cardiac events, particularly in vessel whose tunnel length is long and deeper than 3 millimeters beneath the epicardiaum.^27,39

Coronary Vasculitis

Coronary vasculitis is rare and is associated with a variety of medical conditions including polyarteritis nodosa, Takayasu arteritis, and Buerger’s disease.⁴⁰ LEOs with active coronary vasculitis should be restricted due the increased risk of sudden incapacitating cardiac events.^41,42 Once the vasculitis has resolved, the LEO can return to full duty. However, there is no sensitive or specific test that can determine when the inflammatory process has resolved.

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^bLVEF values are dependent on the imaging technique used, method of analysis, and operator.³⁴ While individual testing facilities have determined their own measures of “normal,” most use a value of greater than or equal to 50%.²⁷

^cPCI procedures encompass a number of catheter-based techniques to treat coronary obstructions.