Introduction
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.
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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.
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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.
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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.
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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.
Current recommendations by several organizations include the
daily use of low dose aspirin to reduce inflammation and clotting
that may lead to heart disease and myocardial infarction. For
additional information, see American Family Physician articles for
the article "U.S.
Preventive Services Task Force: Recommendations and Rationale
Aspirin for the Primary Prevention of Cardiovascular
Events" and an accompanying editorial "An
Aspirin a Day Keeps the MI Away (For
Some)".
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Types of Heart Disease
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.
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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.
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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. |
Stress Testing
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.
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Stress Echocardiography 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.
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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.
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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.
See articles in the New England Journal of Medicine (May 1999) and Circulation (May 1999) on the subject. The
Health Technology Advisory Committee also has a report on Detection of Coronary Artery Disease (CAD) with
Electron Beam Computed Tomography (EBCT), October 1997 and
patient information guidance Electron Beam Computed Tomography for Coronary Artery
Disease, March 1997 (Questions & Answers). A study reported in American Family
Physician indicates that knowledge of EBT scores does not
positively effect cardiac risk factor modification in middle aged
adults. Another analysis in published in American Family
Physician, Coronary Artery Calcium Score Predicts Risk of
CHD, indicates that a high calcium score in high-risk persons
predicts risk of cardiac events. However, there was no
analysis of whether it changed management or
outcomes.
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Coronary Artery Angiography 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.
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Treatment of Coronary Artery Disease -
Coronary Artery Bypass Grafting (CABG)
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.
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Treatment of Coronary Artery Disease -
Percutaneous Transluminal Coronary Angioplasty (PTCA)
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.
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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.
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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.
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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.
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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.
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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.
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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.
Fly & Control Safely!! Fly &
Control Now!!
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