Clinical Practice Guideline
for
CONGENITAL HEART DISEASE
Developed for the
Aerospace
Medical Association
by their constituent organization
American
Society of Aerospace Medicine Specialists
Overview: Congenital heart
disease in adults includes common and uncommon defects, with and without
correction by surgery or catheter-based interventions. Consideration of waiver for continued
military flying duties or training require normal or near-normal cardiovascular
status, acceptably low risk of aeromedically pertinent events and no
significant residua. Otherwise, the most
common congenital disorders that will require aeromedical consideration are
atrial septal defect (ASD) and ventricular septal defect (VSD). Patent ductus arteriosus (PDA) and
coarctation of the aorta may also be seen. Hemodynamically significant defects
are likely to be detected and corrected during infancy or childhood, especially
VSD and PDA. Other, more complicated
congenital disorders will be very unusual because most will be detected in infancy
or childhood and, even if corrected, will be unacceptable for entrance into
military service. They may also preclude
successful civilian flying activities.
ASD
There
are three types of ASD, ostium secundum (75%) [failure
of septum primum to cover the fossa ovalis], ostium primum (15%) [inadequate development of endocardial cushion, thus fails to
close ostium primum], and sinus venosus
(10%) [abnormal embryologic evolution of sinus
venous and sinus valves]. ASDs allow
shunting of blood flow from the left to right atrium, with resultant
right-sided volume overload and enlargement of the right atrium and
ventricle. Presence and time course of
symptom development depends on the magnitude of the shunt; shunts greater than
a 1.5 pulmonary to systemic flow ratio generally produce significant overload with resultant symptoms, including easy fatigue, dyspnea,
and arrhythmias, especially atrial fibrillation. Straining, coughing, Valsalva, anti-G
straining maneuvers or positive pressure breathing may cause the blood flow to
reverse, which could serve as conduit for embolic material. ASDs, even large defects, may not be detected
until adulthood. Prognosis after
successful and uncomplicated closure of significant secundum and sinus venosus
ASD is normal if accomplished before age 25.
Later closure increases the risk of atrial fibrillation, stroke, and
right heart failure.
VSD
Hemodynamically
significant defects are likely to be detected and corrected during infancy or
childhood. Hemodynamically insignificant
VSDs will also likely be detected in infancy or childhood due to the very
characteristic murmur, but may not be recommended for closure because of the
insignificance of the shunt and the likelihood of spontaneous closure over
time. VSDs repaired before age 2 have a
good long-term prognosis.
PDA
PDAs
classically produce a prominent continuous “machinery” murmur heard at the
second left intercostal space. Small
PDAs may escape detection until adolescence or adulthood but are unusual. In the past even small PDAs were often
recommended for surgical or catheter-based closure due to anticipated long-term
risks of heart failure, endocarditis and pulmonary hypertension. Recently, a trend has developed to follow
small PDAs without correction/closure.
The proper course of therapy for small PDAs is not yet established in
the literature.
Coarctation
Coarctation
of the aorta results in elevated blood pressure in the upper limbs, with normal
or low pressure in the lower limbs.
Associated abnormalities with coarctation include bicuspid aortic valve,
congenital aneurysms of circle of Willis, and aortic aneurysms. Unrepaired coarctation with resting gradient
≥ 20 mm Hg between upper and lower extremities carries an increased risk
for progressive left ventricular hypertrophy and subsequent left ventricular
dysfunction, persistent systolic hypertension and premature atherosclerotic
cerebrovascular and coronary heart disease.
Coarctation of the aorta is usually diagnosed in childhood but up to 20%
reportedly are not detected until adolescence or adulthood. Long-term prognosis is related to age of
repair, with the best outcome for correction before age 9.
Patent foramen ovale and atrial septal aneurysm
Patent
foramen ovale (PFO) and atrial septal aneurysm (ASA) are anatomic anomalies of
the interatrial septum. PFO occurs in
25-30% of the general population. At
that frequency it may be considered a normal variant. ASA is present in about 1-2% of the general
population. PFO and ASA may be present
alone or may occur together.
Asymptomatic PFO and/or ASA are typically incidental findings on an
echocardiogram performed for unrelated indications. These are aeromedically considered normal
anatomic variants and therefore are qualifying for all classes of flying duties
including initial training.
However,
PFO and ASA, alone or in combination, have been associated with possible
paradoxical embolic events, notably stroke and transient ischemic attack. Although the relative risk for such an event
is increased, the absolute risk is low.
The occurrence of both PFO and ASA are increased in cryptogenic stoke
populations. Regarding stroke, a
correctable etiology theoretically would alter the risk of recurrent
stroke. Patent foramen ovale (PFO) is
common (autopsy prevalence 29%) and has been associated with stroke. Previously, the risk for recurrent stroke was
thought to decrease to less than 1% after two years if the PFO was surgically
closed or occluded with a transcatheter device and no residual shunt exists,
based on case series demonstrating effectiveness of closure. One retrospective study of 45 patients noted
44 (98%) had no recurrence (mean follow-up 5.3 months) while another
retrospective noted zero strokes in 185 patients (mean follow-up 19
months). While many retrospective
surgical series are showing success there remains to be demonstrated in
prospective randomized controlled studies that percutaneous closure is of
benefit in decreasing the incidence of recurrent stroke. Furthermore, prospective studies of PFO have
not shown a difference in stroke recurrence based on the presence or absence of
PFO. In the PFO in Cryptogenic Stroke
Study (PICSS), a subpopulation of the Warfarin-Aspirin Recurrent Stroke Study
(WARSS), the two-year recurrence incidence was 14.3% with PFO and 12.7% without
PFO for the cryptogenic subgroup (as classified by the TOAST criteria) and
14.8% versus 15.4% for the entire population, irrespective of whether they
received warfarin or aspirin. The French
PFO/ASA (patent foramen ovale/atrial septal aneurysm) study (age less than 55;
mean follow up 37.8 months) noted 4.2% recurrent stroke without PFO, 2.3% with
PFO, and 15.2% with PFO and ASA. Medical
treatment did not alter the recurrence rate in either study. Optimal treatment of PFO and CVA remains to
be defined and at this time medical evidence does not definitively demonstrate
that closure will lessen the likelihood of recurrence. Results of the ongoing randomized studies
comparing medical therapy to percutaneous closure of a PFO are needed before
PFO closure can be recommended.”
Aeromedical Concerns: Aeromedical
concerns are primarily related to the long-term effects of shunting with volume
overload and include, for example, atrial and ventricular dilation and
dysfunction, tachydysrhythmias, endocarditis or endarteritis.
Medical Work-up: The
aviator needs to submit a complete history and physical exam to include description
of any symptoms, treatment, medications, and activity level. Also needed is all ECGs and the official
report of all echocardiograms along with a CD copy of the images, and copies of
reports and tracings/images of any other cardiac tests performed locally for
clinical assessment (e.g. treadmill, Holter monitor, cardiac cath, cardiac CT or MRI).
The official cardiology consultation report is also critical as is the
operative note if surgery occurred. If
the aviator is military, a medical board report may be indicated prior to
consideration for waiver.
Aeromedical Disposition:
Air Force: In the US Air Force, congenital
heart defects, uncorrected or corrected by surgical or catheter-based
procedures, are disqualifying for all flying classes. Also any history of cardiac surgery or
catheter-based therapeutic intervention [including closure of PFO] is
disqualifying for all flying classes.
ASD, VSD and PDA successfully corrected by surgery or catheter-based
techniques, especially in childhood, may be favorably considered for waiver for
all classes of flying duties, as may uncorrected but hemodynamically
insignificant ASD and VSD. Because the
appropriate treatment of hemodynamically insignificant PDA is unsettled;
uncorrected small PDAs will be considered on a case-by-case basis. Coarctation of the aorta will also be
considered on a case-by-case basis.
Army: Generally
congenital heart diseases are disqualifying conditions specified in AR 40-501
Standards of Medical Fitness, the exception being corrected PDA which is not
disqualifying. Of primary concern is
disease that has long term risks, complications, or impact on duty performance.
The exceptions are those congenital
heart disease conditions that can be repaired with resolution of long term
risks, complications, and impact on duty performance.
ASD is discussed in
its own Army APL. Waivers are usually
granted provided complete cardiology work-up is normal and without sequelae, or
post-operatively with normal recovery for all classes. Newly discovered cases of ASD, as well as
patent foramen ovale, undergoing repair with a patch are not deployable for 6
months while they undergo anti-platelet therapy. Cases involving childhood repair require no
periodic follow-up, otherwise, a cardiology evaluation is required every 5
years for waiver continuation including a 24-hour Holter monitor and
echocardiogram with Doppler flow study.
VSD is also discussed in its own APL. Applicants presenting with VSD are not
considered for exception to policy, though applicants with a history of
spontaneous or surgical closure and no significant childhood sequelae may be
considered on a case-by-case basis.
Newly discovered VSD in a rated aviator, with a history of spontaneous
or surgical closure, may be recommended for waiver on a case-by-case basis
provided complete recovery and normal cardiology evaluation.
Navy: Personnel
found to have a Patent Foramen Ovale or
hemodynamically stable ASD are PQ for aviation duty. Hemodynamically stable is
defined as: (1) asymptomatic, (2) no right ventricular enlargement on
echocardiogram, (3) no fixed splitting of S2, (4) normal EKG and (5) normal
CXR. Designated aviators with surgically corrected ASD may be considered for
waiver. Waivers are not recommended for candidates
INFORMATION REQUIRED:
1. Cardiac consultation to include contrast
echocardiography is required.
2. NOMI evaluation may be required.
3. There is a risk of atrial dysrhythmias
following surgical repair of an ASD.
a. Waiver recommendations for this group must include:
i. Serial Holter monitors (monthly over three months)
ii. Repeat contrast echocardiogram to document closure of the
defect.
Civilian: Atrial Septal Defect: The majority of
cases seen have had surgery when they are young. The FAA requires the airman to provide a
complete current cardiovascular evaluation that preferably includes as many of
the pertinent medical records from the surgery as possible. An echocardiogram is also required. Should an airman present with a history of a
peripheral embolus secondary to an ASD it is expected that the defect is
repaired prior to granting medical certification.
Ventricular
septal defect generally also is discovered historically on the medical
history. Once again attempt to obtain
all the pertinent medical records, a current status report from the treating
physician and current echocardiogram.
Coarctation
of the aorta is another historical item that is brought to the attention of the
AME when and airman records such a history on the examination.
One
is expected to follow a similar protocol to clear the airman for medical
certification.
Patent
foramen ovale is generally brought to the attention of the FAA when an airman
has a stroke and it is discovered. Since one cannot be sure that the PFO caused
the stroke, unless it is a large defect, it is expected that the airman is
placed on Coumadin or surgical closure is accomplished. Nevertheless, when an airman has a stroke,
they are grounded for one year if there is a possible correctable etiology,
such as a PFO. As mentioned above atrial
septal aneurysm is considered a “normal variant” when it is discovered on an
echocardiogram usually performed for another reason. The FAA does accept airmen for all classes
when they have had treatment of a PFO.
Waiver
Experience:
Air
Force: Query
of the AIMWTS database showed 39 congenital heart disease cases and of these
cases, 10 were disqualified for an acceptance rate of 74%. Of the 10 disqualified, three were
disqualified for congenital defects not hemodynamically stable (ASD, VSD and
coarctation of aorta), one for a PFO, five for TIA/CVA and one for color vision
deficiency.
Army: The
Aeromedical Epidemiological Data Repository (AEDR) catalogs all Army flight
physicals since 1960. There have been
approximately 160,000 individual aircrew entered in this database. During this period of time, there have been
80 cases of congenital heart disease of all types discovered. Interestingly,
most of these records were prior to 1988.
Of the 80 cases, 48 were retained.
Navy:
Not
available at this time.
Civilian: In the current PATH CODE system at the
FAA they combine all of the congenital heart conditions into one grouping.
There are currently issued: 167 first-, 87 second-, and 350 third-class airmen
with the congenital heart conditions.
|
ICD 9 Codes for
congenital heart diseases |
|
|
745.4 |
Ventricular
septal defect |
|
745.5 |
Patent
foramen ovale and ostium secundum atrial septal defect |
|
745.6 |
Ostium
primum atrial septal defect |
|
745.9 |
Unspecified
defect of septal closure |
|
747.0 |
Patent
ductus arteriosus |
|
747.1 |
Coarctation
of aorta |
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References:
Kruyer
WB. Cardiology. In: Rayman RB, et al eds, Clinical
Aviation Medicine, 4th ed.
New York: Graduate Medical Publishing, LLC, 2006; 243-254.
Maron BJ, Zipes DP, co-chairs.
36th Bethesda conference: Eligibility recommendations for
competitive athletes with cardiovascular abnormalities. J Am Coll Cardiol. 2005; 45(8):
1326-1333.
Strader JR, Jr, Gray GW, Kruyer WB. Clinical aerospace
cardiovascular medicine. In:
Davis JR, et al eds, Fundamentals of Aerospace Medicine, 4th
ed. Philadelphia: Lippincott Williams
& Wilkins, 2008; 338-343.
Webb
GD, Smallhorn JF, Therrien
J, Redington AN.
Chapter 61 – Congenital Heart Disease. In: Libby P, Bonow RO, Mann DL, et al eds, Brauwald’s Heart Disease: A Textbook of Cardiovascular Medicine, 8th
ed. Philadelphia: Saunders Elsevier,
2008.
Prepared
by Drs. William Kruyer and Karen Fox
Date:
September 26, 2010