Coronary artery disease (CAD) is the leading cause of death and disability in the United States. Nearly 14 million Americans have had angina or a heart attack. Over 450,000 will die from this condition each year. Cardiovascular disease is the leading cause of death in the United States contributing to over 40% of all deaths. Each year, over one million Americans will develop angina or have a heart attack for the first time and over one third of these will die from it this year. A quarter of a million people will die within one hour of their first symptom. The American Heart Association (AHA) estimates the annual costs to Americans for heart disease exceeds $250 billion. It is the leading cause of death in men after age 40 and women after age 50. Men have double the death rate from CAD as women do.
Despite these sobering statistics, the death rate from heart disease in the US has dropped dramatically over the last 10 years. The death rate from heart attacks has dropped 28.7% during this time according to the AHA. This drop is attributable to increased awareness and understanding of the disease, aggressive intervention to control risk factors and a shift in public and medical thinking toward prevention.
Airmen and Controller Statistics
The Air Line Pilots Association Aeromedical Office 's experience is that 23% of the over 9000 pilots contacting the office each year do so for cardiovascular disease and 35% of all cases of disability. In 1997, the FAA granted nearly 6,500 Special Issuance Authorizations/SIA (waivers) for pilots with coronary artery disease. Of these, most were for coronary artery disease or heart attacks (myocardial infarctions) treated with bypass grafting, angioplasty and/or intracoronary artery stents. With respect to class of medical certificate, 509 were for First Class, 512 were for Second Class and 5,555 were for Third Class. Pilots with heart valve replacements, rhythm disturbances, pacemakers and heart failure also were granted SIAs. Only 0.1% of medical applications to the FAA receive a final denial.
The bottom line from this information is that cardiac disease is very common. Pilots and controllers should seek early treatment to avoid medical complications and disability. The FAA will routinely waiver adequately treated heart disease, so there should be no reluctance to seek treatment for fear of permanent grounding. Pilots and controllers who optimize their health also optimize their chances for FAA medical certification.
Risk Factors For Heart Disease
There are several well-defined risk factors for coronary artery disease. The risk factors are divided into modifiable and non-modifiable groups. The decreased rates of heart disease over the last 3 decades are attributable to addressing the modifiable risk factors.
The non-modifiable risk factors include male gender, family history of premature heart disease and increasing age. Post-menopausal women not on hormone replacement therapy are also at increased risk, but this is somewhat modifiable.
Men have twice the risk of heart disease than women. This difference narrows with increasing age. People with a family history of heart disease (heart attacks, angina) in a male relative before age 55 and in a female relative before age 60 are at higher risk for CAD. Finally, the risk of CAD increases with each decade of life.
Modifiable Risk Factors
The major modifiable risk factors for heart disease are smoking, diabetes, high blood pressure, physical inactivity, obesity and abnormal blood cholesterol levels. A full discussion of each of these topics if available in other articles in the VFS Information Resource Center.
To briefly summarize the major modifiable risk factors, male smokers increase the risk of CAD by 60-70% over non-smokers. Sudden death due to heart disease is two to four times more likely in smokers. Women who smoke and take birth control pills have up ten times greater increased risk of dying from heart disease and stroke than non-smokers. After 15 years of not smoking, former smokers' risk of CAD returns to non-smoking levels. See the VFS article on Smoking Cessation and Tobacco Abuse for an extensive discussion.
Diabetics have a greatly increased risk of heart disease. Over 80% of diabetics have some form of heart disease. The risk seems to be related to the degree of blood sugar control. The better the control, the lower the risk of heart disease is. Insulin requiring diabetics have an even higher incidence of heart disease. See the VFS article on Diabetes for an extensive discussion.
Like diabetes, people with high blood pressure increase their risk of heart disease directly with poorer control of their condition. Studies show that the higher the blood pressure (both systolic and diastolic), the higher the risk of heart disease. See the VFS article on Blood Pressure and Hypertension for an extensive discussion.
Cholesterol has several components or subtypes. Total cholesterol levels above 200 mg% and LDL cholesterol levels above 130 mg% are at increased risk for heart disease. Lowering these values through diet, exercise, or medication will reduce the risk of heart disease and death. About 51% of Americans have cholesterol levels above 200 mg%. HDL cholesterol below 35 mg% also raise the rate of cardiovascular disease. See the VFS article on Cholesterol Reduction for an extensive discussion.
Overweight (weight more than 20% of ideal body weight or body mass index of 25.0-29.9) and obesity (an elevated body mass index greater than 30) is a common condition. In American adults aged 20-74, approximately 60% of males are overweight and 45-65% of females are overweight varying by ethnic background. Obesity not-only contributes to CAD, but also plays a major role in diabetes, hypertension, back pain, arthritis and stroke. See the VFS article on Obesity and Weight Control for an extensive discussion. Publicity for the high protein, low carbohydrate diets (Atkins) in November 2002 at the American Heart Association Annual scientific Meeting generated much confusion about a proper diet. For information on the AHA's current position, see the AHA Statement on High-Protein, Low-Carbohydrate Diet Study Presented at Scientific Sessions.
Lack of regular exercise increases the risk of death due to heart disease by 1.5-2.4 times according to the AHA. Two thirds of Americans do not participate in enough regular physical activity to help prevent heart disease. Individuals should exercise at least 30 minutes per day, four days per week. This will help control weight, reduce blood pressure, improve cholesterol levels and enhance control of diabetes. See the VFS article on Obesity and Weight Control for an extensive discussion.
Minor Risk Factors
The minor risk factors for CAD also contribute to higher rates, but do not have as significant an impact. Many are interrelated with major risk factors and each other. High dietary fiber intake, avoidance of depression and stress, and adequate nutritional intake (particularly of folate and niacin) have also been associated with reduced rates of CAD. See the VFS Nutrition in Heart Disease Prevention article as well as the article on Vitamins and Minerals for an extensive discussion on dietary and nutrient factors in heart disease prevention. A June 2002 article in The Lancet, a renowned British medical journal, published original research on the positive effects of a diet rich in fruit and vegetables on reducing heart disease.
C Reactive Protein (CRP) is another laboratory study possibly useful in predicting the risk of coronary artery disease. This protein is elevated in a number of conditions that cause inflammation in the body. The inflammatory response is a possible provocateur for atherosclerosis, although the value of testing for this protein is not certain. A recent paper in the New England Journal of Medicine showed the value of determining CRP in women. For more information see the American Heart Association article on C Reactive Protein and associated links.
Disease of the heart may involve the coronary arteries, the electrical conduction system, the heart valves or the heart muscle. The most common type of heart disease is coronary artery disease (CAD), which is discussed in this article. CAD involves the narrowing of the four major vessels supplying blood to the heart. This narrowing is similar to the clogging of a pipe. The process of narrowing is termed atherosclerosis or "hardening of the arteries." It occurs in all parts of the body, but when it occurs in the heart, the term coronary artery disease is used.
The narrowing process starts with deposits of cholesterol on the inner walls of the blood vessels to form soft "plaques." These plaques are similar to the greasy soft buildup in a kitchen pipe. Gradually, more plaque is deposited and the diameter of the coronary arteries narrow. This narrowing is termed "stenosis". Less blood flow is able to reach the heart muscle, just as a drain slows as it clogs. Some research indicates that aggressive lowering of cholesterol complemented with exercise may reverse this clogging plaque.
Later, the plaque damages the lining of the blood vessel, called the intima, triggering a reaction that converts some of the soft cholesterol plaques into hardened "calcified" narrowings. This calcification generally is not reversible without some type of surgery. Despite all the blood in the body running through the heart, only that blood that is pumped out of the heart and back through the coronary arteries to the heart muscle actually supplies oxygen to the heart.
Symptoms of CAD
As long as the oxygen and blood supply demands to the heart muscle are not too great, a person with CAD has no symptoms. When greater demands of exercise or progressive narrowing of the coronary arteries limits blood flow to the heart muscle, symptoms of CAD begin to occur. These symptoms include a tightening or pressure in the chest (angina), pain in the neck, jaw or arm with exercise, shortness of breath or a sense of anxiety. These symptoms deserve immediate attention. The New England Journal of Medicine published an interesting article in June 2002 on the mechanisms of angina and how the symptoms are produced.
Unfortunately, approximately one third of people with CAD may have a disturbance in the rhythm of the heart or sudden cardiac death as the first symptom. Angina, which represents reversible interruption of adequate blood flow to the heart, may progress to a heart attack, also known as a myocardial infarction. A heart attack usually causes permanent damage to the heart muscle, leaving a scar in a portion of the heart rather than contracting muscle.
Evaluation of CAD
The evaluation of CAD is usually a stepwise process of less invasive, less expensive testing moving toward more definitive testing which cost more and may involve more risk.
History Physical and Labs
The most basic evaluation involved the physician discussing the "history" and performing a physical exam and laboratory studies. The history includes a personal account of any symptoms, any relatives with early heart disease, lifestyle, habits and risk factor analysis. The physical examination evaluates blood pressure and heart/lung sounds, but is a relatively weak tool to detect CAD. Laboratory studies check cholesterol levels, blood sugar (diabetes), and electrolyte levels (high blood pressure and kidney failure).
Electrocardiogram (ECG / EKG)
The next stage of evaluation is a resting electrocardiogram (ECG or EKG). The ECG is a snapshot look at the rhythm and character of the electrical activity of the heart. Each individual has a relatively unique pattern on the ECG which does not change significantly during a lifetime unless there is some damage to the heart. The FAA First Class medical certification requires a baseline ECG on the initial First Class physical after age 35 and annually after age 40. This is to look for changes and evidence of damage. See the VFS Medical Information section feature on "ECG Variants" for a more complete discussion. A person with rather advanced CAD may have a completely normal ECG. The weakness of the ECG is that it only can give indications of the past and present, but cannot predict the future.
Exercise stress testing is a provocative test in a controlled monitored setting designed to detect CAD before severe symptoms exist. By forcing the heart to work near its maximum capacity, the physician can look for changes on the ECG characteristic of "reversible ischemia." These changes indicate the heart gets enough blood flow and oxygen at rest, but not enough with stress. This is similar to comparing the power output of a piston engine at sea level versus at a high density altitude.
A person being tested has ECGs taken at rest and with hyperventilation as baseline readings, and then starts to walk on the treadmill. The ECG is monitored continuously and recorded every one to three minutes. The Bruce Protocol is the standard testing method. A Bruce stress test increases the speed and incline of the treadmill until any one of several endpoints is reached. These endpoints include complete fatigue, reaching a target heart rate (usually 85-100% of predicted maximum for age), cardiac rhythm problems or symptoms of angina.
The baseline, maximum exercise and recovery ECGs are compared, looking to diagnose or exclude CAD. Occasionally, the baseline ECG has abnormalities that make interpretation of a stress test difficult or impossible. For the individual who cannot walk on a treadmill, the heart rate can be increased with the administration of several intravenous drugs, adenosine, dipyridamole or dobutamine.
A more sophisticated type of stress testing involves taking an echocardiogram of the heart at rest and with exercise, in addition to recording the ECG tracings. The echocardiogram involves using a ultrasound transducer on the chest to take a two dimensional and Doppler image of the heart walls. The echocardiogram can assess the pumping efficiency of the heart. In people with CAD, the echocardiogram may show poor contraction of the heart muscle with high stress. This occurs because the heart does not get enough blood through the coronary arteries to function properly, similar to a failed fuel boost pump.
Radionuclide Stress Testing
None of the above procedures can quantify the amount of blood from the coronary arteries reaching the heart. Myocardial perfusion imaging or radionuclide stress testing gives an estimate and picture of blood flow to regions of the heart muscle at rest and with stress. In addition to a stress ECG, people undergoing this testing receive an injection of a brief acting radioisotope. The radioisotope flows through the blood and collects in the heart muscle where a specialized scanning camera evaluates the quantity of blood reaching each part of the heart. The camera rotates around a patient to create images representing "slices" of heart muscle viewed from several angles. The scanning technique is called Single Photon Emission Computed Tomography (SPECT).
The blood flow at rest is compared with the blood reaching the heart muscle (myocardium) during stress. Four possible outcomes are reported. If the rest and stress images are uniform, indicating the myocardium has adequate blood flow, with stress and rest, the results are reported as no evidence of fixed or reversible ischemia. This is a normal study or "no evidence of fixed or reversible ischemia".
The second possible outcome is a "fixed perfusion defect." This indicates that a portion of the myocardium is not getting blood flow with stress or at rest. A previous heart attack (myocardial infarction) is the usual cause. A fixed perfusion defect is not necessarily disqualifying for flying after an appropriate observation period and treatment of underlying CAD.
The third possible outcome is a "reversible perfusion defect." This reversible defect is caused by a portion of heart muscle that receives marginal blood flow. The myocardium receives enough blood at rest, but when stressed with exercise, inadequate amounts of blood reach a portion of the heart. The scanning camera demonstrates reversible perfusion defects as a doughnut hole appearance in the heart image with stress that fills in at rest. Reversible perfusion defects are generally disqualifying for medical certification because a portion of the heart muscle is in jeopardy for further damage or electrical irregularities in the heartbeat. Reversible perfusion defects indicate ongoing and possibly progressive heart disease that should be treated if significant.
The fourth possible outcome is an equivocal test, frequently caused by "possible diaphragmatic attenuation." The position of the heart in the chest, particularly in heavier people, may be partially shielded from the scanning camera by the diaphragm. The diaphragm is the slightly curved muscle that separates the heart and lungs in the chest from the organs in the abdomen. This "diaphragmatic attenuation" may look similar to fixed or reversible perfusion defects, particularly in the bottom (inferior) portion of the heart. This result may be acceptable for medical certification or may require further evaluation.
Types of Radionuclide Testing
Three types of radionuclide testing are common. All use radioisotopes that have a short half-life and are quickly eliminated from the body after injection into the blood stream. The isotopes collect in the heart muscle (myocardium) and are quantified by a scanning camera that detects radioactive signals. The camera generates a picture of the thick myocardium of the left ventricle. Black and white pictures similar to x-rays are called scintigrams. Heart muscle with adequate blood flow appears black. Areas of poor blood flow are lighter, similar to a hole in a doughnut and are termed "perfusion defects." Color photographs can also be computer generated where colors represent amount of blood flow. See an article in American Family Physician on "Radionuclide Imaging in the Evaluation of Heart Disease" for a complete explanation.
The most common types of radionuclide testing involve the use of thallium-201, technetium-99 sestamibi (Cardiolyte testing) or both (dual isotope scanning). Thallium testing requires injection of the isotope at maximum exercise with immediate scanning followed scanning several hours later to get the rest images. Cardiolyte testing uses an injection and scanning at rest followed by exercise and repeat injection and scanning. The dual isotope scan combines both techniques. Many cardiologists prefer to do Cardiolyte testing because it is faster, more flexible in technique and the isotope is easier to handle. The FAA cardiology consultants prefer Thallium or dual isotope scans, feeling that these studies have a lower false negative rate than Cardiolyte studies. However, If initial diagnostic studies were done with Cardiolyte, the consistency in study techniques makes follow-up Cardiolyte imaging acceptable.
PET Scanning of the Heart / Ultrafast CT (Cardioscan) / EBCT
New technologies attempting to define areas of stenosis and decreased blood flow include the Position Emission Tomography (PET) and Ultrafast CT scans. Both of these techniques are relatively new non-invasive ways of detecting CAD. Neither has been studied enough to state that it is superior to the commonly used radionuclide scans. The FAA updated its policy on positive finding on Ultrafast CT scans of the heart. Previously, the results were of no significance to the FAA, regardless of the results. The policy as of October 2001 considers the presence of any calcification in the coronary arteries as potentially disqualifying for certification. If calcifications are noted, pilots and controllers must obtain nuclear stress testing to further define the risk of heart disease. The FAA does not accept the results of PET/CT scans as substitutes for required testing following treatment for cardiac disease.
PET scans are very similar to thallium studies, but use a different tracers to image the heart. Currently, rubidium-82 is the only FDA approved tracer. The advantages of this technique are speed, improved sensitivity and non-invasive nature. The disadvantages are the cost and the relatively minimal experience with the technique in co-relating PET findings with angiograms. The American Heart Association recently stated the PET scan does not yield superior diagnostic accuracy compared to SPECT scanning.
Ultrafast CT scans, now called electron beam computed tomography (EBCT), can detect calcium deposits of atherosclerosis in coronary arteries. The test can be done on almost anyone in 10-15 minutes. People with high degrees of calcium in the artery have increased risk for heart disease. The weaknesses of the test include the lack of correlation between the location of the calcium and the degree of narrowing of the coronary arteries. Some degree of stenosis comes from soft plaque that has not formed calcium. Therefore, an individual may have significantly more narrowing than indicated by the EBCT. The EBCT does not give any information about actual blood flow to the myocardium.
Although heavily advertised in some areas, no heart organization has recommended the ultrafast CT for routine screening. A positive test result (those showing ANY calcium in the coronary arteries, even if low-risk) should be evaluated using other techniques. A positive EBCT/UFCT currently is disqualifying for FAA certification, pending evidence from exercise stress testing that here is no evidence of ischemia. For this reason, Virtual Flight Surgeons recommend pilots carefully consider the effects of this testing on both health and FAA certification prior to undergoing testing by this technique. The evaluation does generate a reporting obligation on the next FAA physical exam, even if no disease was found.
The most definitive test of blood flow through the arteries that supply blood to the myocardium is coronary artery angiography or arteriography. The procedure involves using a catheter (thin hollow tube) inserted into the blood vessels of the groin or arm. The catheter is routed back to the heart by visualizing the catheter under a fluoroscope (real-time x-ray). The tip of the catheter is inserted into the opening (ostium) of each of the coronary arteries and a dye visible by the fluoroscope is injected. The dye fills each artery. Areas of narrowing (stenosis) of the coronary artery do not fill with dye. The degree of narrowing is expressed as a percent of the full diameter of the coronary artery. Several views (projections) of each narrowing are viewed to construct a three dimensional picture of the stenosis from two dimensional views. The images are recorded on 35 mm film or on a CD-ROM. Defects noted on radionuclide imaging are compared to areas of stenosis on angiography. Areas of significant (>50%) stenosis are often accompanied by reversible radionuclide perfusion defects "downstream" from the stenosis.
Significant Coronary Artery Disease Defined
Unlike many other medical conditions which are either present or not present, CAD exists to varying degrees in almost all adults. Whether one degree or another of CAD is significant depends on the perspective of the evaluator. Medical significant CAD might be defined as that causing symptoms such as angina, decreased exercise tolerance or shortness of breath. This degree of symptoms usually correlates with stenosis of greater than 90%. Others may consider any stenosis of 75% or greater significant with a positive radionuclide scan. The FAA uses a conservative figure of approximation 50% stenosis with a positive radionuclide scan in an area of the heart corresponding to the stenosis. The FAA uses this conservative position of aeromedical significance because of the margin of safety required for aviation and because airmen are medically certified for 6 months to three years. The dilemma facing pilots with aeromedically significant lesions (50-75%) that their treating physicians do not consider medically significant is how to do what is medically appropriate and retain medical certification. FAA certification may depend on the presence or absence of reversible ischemic defects on radionuclide imaging in the area of myocardium supplied by the stenotic vessel.
The original surgical treatment for CAD and stenosis is CABG. In this technique, an incision in the chest and rib cage exposes the heart and coronary arteries. Arteries from the chest can be repositioned to attach to a narrowed coronary artery "downstream" from the stenosis. Similarly, veins from the leg are used to "bypass" the stenosis by attaching them to the major artery from the heart (aorta) to the blocked coronary artery. Blood flow is re-established beyond the blockage.
Some blocked vessels are too small to bypass, although CABG can often be done in areas where angioplasty cannot. Newer "keyhole", or minimally invasive, procedures allow CABG without splitting the rib case. The CABG is completed through a small incision between the ribs. The American Heart Association and American College of Cardiology published Practice Guidelines for Coronary Bypass Surgery in 1999.
Approximately 10-15% of by-pass grafts will restenose (close off) over time. The FAA requires a six month observation period following CABG before applying for reinstatement of a medical certificate to minimize pilots with early restenosis returning to flying with significant and persistent heart disease. Arteries used for by-pass grafts tend to have better outcomes and lower early restenosis rates than do veins.
A newer technique to open narrowed coronary arteries is termed the percutaneous transluminal coronary angioplasty or balloon angioplasty. The PTCA is done using a catheter similar to the angiography catheter, only equipped with a narrow balloon near the end of the catheter. The tip of the catheter is passed through the narrowed area until the deflated balloon portion is inside the stenosis. The balloon is inflated to several atmospheres of pressure, pushing the cholesterol-narrowed walls of the coronary artery open. Frequently, the stenosis is reduced to less than 10% of the vessel diameter.
The advantages of the procedure are the speed and avoiding major surgery requiring opening the chest. Most people return home the same day as the PTCA. The disadvantages of PTCA include the inability to "balloon" total obstructions or stenosis located at the far end of a coronary artery. The possibility of treating or rupturing a coronary artery with the balloon requires emergency CABG team back-up. Though the experience with PTCA is not as long as with CABG, some concerns exist that a PTCA will not last as long as a CABG.
Treatment of Coronary Artery Disease - Stent Placement
A refinement of the PTCA designed to decrease the likelihood of restenosis after PTCA includes placing a stent inside the coronary artery after balloon angioplasty. Stents are similar to the wire springs/coils inside a ball-point pen. They overlie the balloon portion of the PTCA catheter and expand when the balloon is inflated. After deflation, the stent remains expanded in the previously narrowed vessel providing a structure similar to fuselage tubing. The stents are about 1/2-1 cm in length and several millimeters in diameter. Once in place, they cannot be removed. See the American Heart Journal article on stent implantation during heart attacks.
Some individuals have restenoses of stents several weeks to months after placement. A developing technology uses stents coated with radioisotopes to decrease tissue growth around the stent. These seem to have improved rates of remaining patent than do standard stents. See an article in the April 18, 2002 issue of the New England Journal of Medicine for more information.
A new technology stent that secretes an anti-inflammatory type substance to lower the risk of early restenosis was approved by the FDA in April 2003. According to preliminary research published in the New England Journal of Medicine, the restenosis rate for these stents has been lowered to 4% compared to a rate of 27% in non-treated stents. The newer stents are very expensive, but given the lower rate of requirements for repeat procedures for restenosis, may be just as economical if widely used in a large population.
Treatment of Coronary Artery Disease - Arthrectomy
Atherectomy involves using a catheter in the coronary artery with a high speed burr at the tip to bore through a narrowing of the vessel. A common lay person term is "rotoblator" or "roto-rooter." Different types of arthrectomy include directional, rotational and extraction. Laser arthrectomy is an alternative to the mechanical types described above. Following arthrectomy, angioplasty can be performed on the same vessel. The procedure is not very common.
Treatment of Coronary Artery Disease - Thrombolytic Therapy
In some cases, heart attacks (myocardial infarctions) are caused by a blood clot obstructing and already narrowed coronary artery. This clot is called a thrombus. If detected and treated within a few hours of onset, the damage from a heart attack can be minimized if the thrombus is dissolved. The procedure to dissolve the clot involves the use of coronary artery catheterization and the infusion of "clot busting" (thrombolytic) blood thinners into the artery. The presence of a clot as a possible cause of a heart attack is the reason many physicians recommend anyone with chest pain resembling angina take an aspirin as soon as possible and seek care. Aspirin can inhibit the formation of clots and may also reduce the damage from a heart attack. Thrombolysis is not a treatment for heart disease without acute infarction and must be performed within hours of the onset of symptoms to be beneficial. Please see the Health Technology Advisory Committee report on Thrombolytic Therapy for Acute Myocardial Infarction, May 1994 (Executive Summary).
Non-Invasive Treatment of CAD
Some people wish to avoid any surgery to treat CAD. None of these techniques work as quickly the more invasive procedures. Moreover, there is minimal scientific evidence documenting actual reversal of CAD. Early research supports the role of aggressive lowering of the LDL cholesterol and homocysteine levels with medications, vitamins and nutritional supplements to possibly reverse CAD. The 71st Annual Scientific meeting of the American Heart Association published a study that the lowering of LDL cholesterol to levels below 100 mg/dL resulted in a lower than expected number of heart procedures compared to those who had angioplasty. For the pilot, the long duration of non-interventional therapy before any change in the extent of CAD is seen usually makes a return to the cockpit after disqualification a lengthy process, if successful.
An accepted method of treating CAD in those who find the risk of surgery unacceptable is medical management. With this therapy, medications are used to minimize symptoms of CAD and maximize heart function. Nitroglycerin and other medications are used. Some research indicates aggressive lowering of cholesterol levels with medication, diet and exercise may possibly reduce the degree of CAD stenosis, although minimally. Although the FAA allows pilots to take most heart medications if there is no evidence of ischemia, the use of nitroglycerin usually indicates a tangible risk of ischemia and is disqualifying.
One treatment that is sometimes attempted is chelation therapy. This "treatment" uses repeated doses of a chemical designed to bind metals in the blood stream. This binding is supposed to reverse atherosclerosis. The Mayo Clinic, American College of Cardiology, National Institutes of Health and FDA conclude this technique is not effective. Many physicians consider chelation quackery when used for CAD. The January 23/30, 2002 issue of the Journal of the American Medical Association included an article showing no objective benefit from chelation therapy in terms of exercise capacity and quality of life measurements.
FAA Testing for CAD
The diagnosis of coronary artery disease requiring treatment, manifesting by a heart attack or evidence of ischemia (symptoms or diagnostic testing) is disqualifying for all classes of FAA medical certification. A positive stress test requires further testing with more definitive testing before returning to fly or control. This testing includes radionuclide stress testing or stress echocardiography. If these results show evidence of reversible ischemia, a pilot or controller is disqualified pending the results of coronary angiography. In general, lesions with stenoses of 50% or greater are disqualifying for flying/controlling until reversed.
For pilots, a heart attack or intervention procedure for treatment of CAD triggers a minimum of a 6 month observation period before repeat evaluation for FAA recertification through the Special Issuance Authorization (SIA) procedures of FAR Part 67.401. For First Class and unrestricted Second Class SIA, the follow-up testing must include radionuclide stress testing (preferably Thallium or dual isotope) and repeat coronary artery angiography. No indication of reversible ischemia on radionuclide testing and all lesions less than 50% stenoses are required for favorable SIA consideration. Generally, follow up studies are required every 12 months with stress testing and every 24 months with radionuclide stress testing. Some cases may require follow-up reports every six months.
Restricted Second Class and Third Class certification does not require repeat angiography. If a case is uncomplicated, a Maximal Exercise Stress Test may be sufficient follow up. If there is a question of cardiac muscle damage, a radionuclide stress test may be necessary (VFS physicians can help you with this decision). Stress echocardiography is an acceptable substitute for radionuclide stress testing for Third Class SIA only. Go to the VFS FAA Forms and Protocols in our Information Resource Section for copies of specific requirements.
For controllers with coronary artery disease and intervention, the FAA requires only a three month wait before maximal exercise stress test follow up to petition for Special Consideration to return to controlling duty. For contract controllers that operate under a 2nd class airman certificate, the FAA will still consider returning to controlling after only 3 months.
The requirements for the basic FAA heart evaluation for all cardiac conditions including hypertension, arrhythmias, coronary artery disease and heart surgery are delineated in FAA Form 8500-19, Specifications for Cardiovascular Evaluation. More serious heart conditions require additional evaluations beyond those listed in the 8500-19.
FAA Testing for CAD - FAA Forms and Protocols for Cardiovascular Conditions
Please see the VFS Forms and Protocols page of our Information Resouces section for a complete listing of all FAA forms and protocols for a variety of cardiovascular conditions.
The results of all diagnostic testing and treatment records must be forwarded to the FAA Aeromedical Certification Division for SIA consideration. The biggest delays in certification result from pilots not submitting complete records, include complete ECG tracings and scintigrams/photographs/VHS cassettes from stress testing and 35 mm films from angiography. The results of a recent cardiovascular evaluation must also be included in the submission.
These summaries and other test results may be mailed to the FAA at :
Federal Aviation Administration Aeromedical Certification Division CAMI Bldg./ AAM-300 P.O. Box 26080 Oklahoma City, OK 73126-9922
However, airmen and controllers should be aware that often well-meaning specialists may not necessarily be cognizant of all the aeromedically significant aspects of a case. Incomplete, erroneous, or unclear information can result in significant delays or potential denials.
What heart conditions are not waiverable by the FAA?
Very rarely, a pilot will be diagnosed with a condition that is not waivered by the FAA. Until recently one condition is a heart transplant, or as stated in Part 67 of the FARs, "cardiac replacement." In the past, a few pilots were waivered for this condition, but complications led to a more conservative FAA position. In the Winter of 2006, the FAA revisited this policy and appear willing to consider waivers after a 12 month observation for third class only.
A diagnosis of IHSS (Idiopathic Hypertrophic Subaortic Stenosis) is also currently disqualifying for all classes of medical certificate, although some cases meeting very specific criteria may be considered for 3rd class certification. See an article on IHSS from the Federal Air Surgeon's Spring 1999 Medical Bulletin. Another article from the New England Journal of Medicine January 23, 2003, addresses clinical outcomes in this condition.
The Aeromedical Certification Division has stated that related syndromes might be considered for Special Issuance if there is no evidence of cardiomyopathy. Each case is evaluated individually and subject to periodic review. One case of IHSS was granted a Special Issuance in early 2002 following an appeal to the NTSB. Whether further cases will be certified without legal appeal remains to be seen.
Some pilots with cardiac pacemakers may get waivered to fly. Until recently, those who are characterized as "pacemaker dependent" for a heart rhythm were not waivered. The FAA does have a written protocol for pilots with pacemakers to petition for certification. See an article on pacemaker failure in a pilot with congenital heart conditions from the Federal Air Surgeon's Winter 1998 Medical Bulletin. Note that the pilot was initially waivered despite a variety of heart conditions. Also see the Aeromedical Certification Update on pacemaker policy and Consideration of Pacemakers Case Study, by Susan Ferguson, MD in the Fall 2001 Bulletin. The VFS article on Arrhythmias - Abnormal Heart Beats has extensive information on conditions that may lead to pacemakers.
Currently, the FAA does not waiver any pilots with Automatic Internal Cardiac Defibrillators (AICDs). This policy is being reviewed, but no change in the policy is anticipated. Individuals diagnosed with Arrhythmogenic Right Ventricular Dysplasia (ARVD) frequently will have an AICD placed prior to having any significant cardiac event. Some individuals who have been successfully resuscitated from Sudden Cardiac Death (Ventricular Fibrillation with loss of consciousness) will also have AICDs placed.
VFS Certification Assistance
This is a very broad overview of a complex subject with many nuances. The VFS aerospace medicine physicians work with hundreds of pilots and controllers with cardiovascular disease each year, working to obtain FAA medical certification at the earliest possible time. Over 85% of those treated for CAD are expected to return to the cockpit or control tower after appropriate information is forwarded to the FAA.
For expedited responses and more specific explanation, contact VFS direct for assistance.
For a more specific personal explanation to your questions or those concerning aeromedical certification, contact VFS for a private consultation. For help in reporting treatment for and obtaining clearance from the FAA to fly or control with these conditions, refer to the VFS Confidential Questionnaire. If you are a VFS Corporate Member, these services are FREE to you.