Clinical Practice Guideline

for

CORONARY ARTERY REVASCULARIZATION

Developed for the

Aerospace Medical Association

by their constituent organization

American Society of Aerospace Medicine Specialists

 

Overview: Coronary artery revascularization includes coronary artery bypass graft surgery (CABG) and percutaneous coronary intervention (PCI), catheter-based techniques such as angioplasty and stent).  It is very important to realize that these procedures are palliative, not curative.  If revascularization is deemed successful after short-term follow-up of 6-12 months, future cardiac events are primarily caused by progression of coronary artery disease (CAD) elsewhere.  Within two years after interventional therapy, new significant lesions (> 50% stenosis) may develop at other sites at rates of 7-15% per year.

 

Recent trials with up to seven years follow-up are available, usually comparing PCI versus CABG or angioplasty versus stent.  Post revascularization annual cardiac event rates seem to be in the range of 1.0%-3.0% per year for cardiac death and nonfatal myocardial infarction (MI) plus an additional 2.0-8.0% per year for second revascularization procedure.  These trials include better prognostic subgroups with normal left ventricular function, no prior myocardial infarction, and only single or double vessel disease.  Cardiac death plus nonfatal MI event rates are comparable for CABG versus PCI with a trend usually favoring CABG.  Regarding next revascularization, rates are significantly lower for CABG versus PCI and for stent versus angioplasty.  Most of these papers include any repeat revascularization within the first 6-12 months post procedure.  For aeromedical purposes, only revascularization performed after an initial six month observation would be pertinent.

 

From US Air Force databases 122 former military aviators with coronary artery revascularization but no prior cardiac events were followed for occurrence of next cardiac event - about half the group had CABG and the other half had PCI, primarily angioplasty.  There were no cardiac deaths within five years and only two myocardial infarctions, both beyond two years follow-up.  After excluding repeat revascularization within six months of the index revascularization, cardiac event rates were 1.0%, 2.7% and 3.6% per year at one, two and five years follow-up, respectively.  Individuals meeting the below waiver criteria have estimated cardiac event rates of 2-3% per year for up to five years after revascularization.

 

Recently a selected group of 30 Air Force aviators that presented to US Air Force Aeromedical Consultation Service (ACS) while on active duty (2000-2008), after having had coronary revascularization, were chosen for a retrospective study to determine the time to event and resulting annual event rate.  Out of these, only two progressed to need revascularization.  There were no deaths and no MIs.   The annual event rate was 2.1% (CI 1.2% - 3.0%). The event free survival was 97% at two years and 88% at 5 years.  Both of these patients would have been identified during the annual ACS reevaluation as required by policy.  Neither would have manifested as an incapacitating event.

 

Aeromedical Concerns: The aeromedical concern is myocardial ischemia presenting as sudden cardiac death, myocardial infarction, angina or ventricular dysrhythmias, all of which may cause sudden incapacitation or seriously impact performance of flight duties.  Detecting the asymptomatic progression of CAD reliably without frequent invasive testing or noninvasive monitoring is the aeromedical challenge.

 

Medical Work-up: The aviator needs to submit a summary to include complete history of the event, emergency care rendered, and testing done to include all results.  In addition, a copy of the cardiac catheterization report and copy of the images (CD, cineangiogram or videotape) is required.  All additional cardiac testing (to include copies of reports and tracings such as ECGs, treadmills, nuclear imaging tests, etc.) as well as a thorough cardiology consultation report is needed.  Specifically, what is needed for aeromedical disposition is a copy of the cardiac catheterization report and copy of the images as well as a copy of the revascularization procedure report (CABG or PCI).  If military, the aviator will need to complete a medical board.

 

Aeromedical Disposition:

 

Air Force: Coronary artery disease and coronary artery revascularization are disqualifying for all classes of military flying duty.  ACS review and evaluation is required for waiver consideration.  Waiver restricted to low performance aircraft may be considered for all flying classes.  Waiver for pilots, limited to low performance aircraft with another qualified pilot was approved by the Air Force in 2008.  Criteria for waiver consideration include but are not limited to normal left ventricular wall motion and systolic function, complete revascularization (all lesions >50% stenosis successfully revascularized), sum of nonsignificant lesions <120%, no noninvasive testing evidence of reversible ischemia off cardioactive medications, for PCI no restenosis >50%, successful risk factor modification and minimum DNIF observation period of six months post procedure.  ACS evaluation for initial waiver consideration will include complete noninvasive testing and follow-up coronary angiography.  If waiver is recommended and granted, waiver will be valid for one year with annual ACS re-evaluation required for waiver renewal consideration.  In addition, routine serial coronary angiography is required at three year intervals.  Follow-up coronary angiography may be recommended sooner if indicated by symptoms, noninvasive test results or failure to control risk factors.

 

Army: Coronary artery disease is a disqualifying condition for Army service including rated and non-rated air crew.  Aviators who undergo revascularization or other corrective surgical procedures (stents) may be considered for waiver 6 months after their procedure.  Aviation applicants who have undergone revascularization are not considered for waiver.  In the case of rated aviators revascularization is considered on a case by case basis and may result in a restricted waiver for aviators with unique, mission critical skills.  Such waivers may be granted in the cases when the following criteria have been met:  1) cleared by attending physicians; 2) aggressive risk reduction and modification with therapeutic lifestyle changes and aeromedically approved medications; 3) post-recovery assessment and testing documenting extent of healing, persisting scar/damage, perfusion adequacy around the affected area as demonstrated by perfusion test at 6 months; 4) no abnormal dysrhythmias on Holter monitor; 5) Ejection fraction above 50%; and 6) completion of MEB/PEB process for military aviators. All will be reviewed by an Aeromedical Cardiology Consultant.

 

Navy: Individuals with CAD and revascularization are NPQ for all flying duties.  Waiver recommendations may be made only after cardiovascular evaluation and careful consideration of aeromedical risk. Risk assessment will be based on but not exclusively the following:

 

1.     The presence or absence of significant lesions or plaque burden.

2.     History of acute coronary syndrome (ACS).

3.     Effective risk factor modification.

 

Local board of flight surgeons: NO provisional clearances for any class. Initial waivers at NAMI: Applicants: WNR; Designated: All classes, considered      

 

INFORMATION REQUIRED: Cardiology consultation. The primary goal of cardiology evaluation is to obtain an assessment of atherosclerotic ‘disease burden,’ along with cardiovascular functional capacity including assessment for active ischemia. The consultation should include recommendations on optimal management of modifiable risk factors. The ‘state of the art’ in evaluating the components required in order for waiver to be considered continues to evolve; therefore specific tests may/will be selected by the consultant. Submit copies of any reports, to include anatomic assessment or “scoring”, functional test, and blood chemistries. NAMI may request additional studies. Address waiver requirements for medication.

 

1.     Maximal exercise stress testing to include imaging modality.

2.     Laboratory results to include Lipid profile, Liver profile, Fasting glucose, Electrolytes, Creatine kinase, high sensitivity C-Reactive protein

3.     History and physical examination studies documenting full achievement of risk factor control. Document compliance with standard medical regimen per ACC/AHA guidelines; lipid management according to NCEP guidelines, blood pressure control per JNC guidelines, BMI <=27, and normal Fasting glucose.

4.     Statement from member documenting tobacco cessation (see example) if applicable and/or compliance with aerobic exercise program as prescribed by ACC/AHA guidelines (see example)

5.     AMS documenting compliance with medications along with optimization of blood pressure and body composition (BMI < 27). BMI goal should be attained within 12 months of diagnosis

 

Civilian: Three of the FAA's fifteen specifically disqualifying medical conditions are related to coronary artery disease: 1) coronary artery disease that is symptomatic or has required treatment; 2) myocardial infarction; and 3) angina pectoris.  The FAA allows all forms of treatment for coronary disease to include angioplasty, stent, atherectomy, brachytherapy, and coronary artery bypass grafting.  They also permit certification for all classes of medical certificates.  These conditions usually result in the requirement for an authorization for special issuance (waiver).  It is an Office of Aerospace Medicine policy that all first- and second-class certificate holders have their cases reviewed by a Federal Air Surgeon cardiology consultant.  A Cardiology consultant panel meets every other month at the Civil Aerospace Medical Institute in Oklahoma City and by a visiting consultant on the other months.  Airmen with any corrective procedure for coronary disease has a mandatory 6 month period of “observation” or “grounding” after the procedure prior to their being considered for certification.  First- and second-class airmen are required to have a post event cardiac catheterization 6 months post treatment for consideration.  The FAA has yet to accept the use of coronary CT-angiography to follow these airmen.  These airmen also must have a functional evaluation by nuclear stress testing initially and every 24 months for recertification.  Third-class airmen are only required to have a plain Bruce protocol stress test unless the study is positive, then a stress echocardiogram or nuclear stress is required for consideration. 

 

In general an airman for consideration is not permitted to have ischemic changes on stress testing to be considered even if this ischemia is asymptomatic.  One should understand that this could lead to cardiac arrhythmias.  Third-class or private pilots are allowed to have their cases reviewed at the regional flight surgeon or Aerospace Medical Certification Division level. 

 

Since angina pectoris is one of the fifteen specifically disqualifying medical conditions, one cannot have any anginal pain and fly even if the angina is stable.  The airman is required to be grounded and observed for six months after a bout of angina prior to being considered.  Nitroglycerin vasodilating agents are not permitted in the civil aviation environment even if they are being used to treat a different condition such as esophageal spasm.

 

Waiver Experience:

 

Air Force: Query of AIMWTS revealed 28 submitted cases with a history of revascularization.  Of the 28 cases, 18 were disqualified, most due to the fact that their cases came under consideration before there was an opportunity for them to be waived due to policy at the time.

 

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 were 17 rated aviators for which aeromedical summaries were submitted resulting in 9 medical suspensions.  During the same period there were 5 waiver requests for non-rated personnel among which 3 were medically suspended.

 

Navy: Not available at this time.

 

Civilian: As of June 30, 2010 with the condition Coronary Artery disease with Stent, there are currently issued: 569 first-, 437 second-, and 3,110 third-class airmen.

 

As of the same date those airmen currently issued with just percutaneous transluminal angioplasty: 181 first-, 141 second-, and 850 third-class. The airmen in this category could have multiple angioplasties. 

 

As of June 30, 2010 there are currently issued with the condition of coronary artery disease with coronary bypass grafting: 269 first-, 240 second-, and 2,284 third-class airmen.

 

There are currently issued with coronary artery disease with coronary Atherectomy: 16 first-, 14 second-, and 90 third-class airmen.

 

ICD 9 Codes for coronary artery disease

414.00

Coronary artery disease

36.10

Coronary artery bypass graft (CABG)

36.06

Coronary artery stent placement

36.09

Coronary artery angioplasty

 

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References:

 

Barnett SL, Fitzsimmons PJ, Kruyer WB.  Coronary artery revascularization in aviators: outcomes in 122 former military aviators.  Aviat Space Environ Med. 2003; 74(4):  389- abstract for 2003 Meeting.

 

Betriu A, Masotti M, Serra A, et al.  Randomized comparison of coronary stent implantation and balloon angioplasty in the treatment of de novo coronary artery lesions (START): A four-year follow-up.  J Am Coll Cardiol.  1999; 34(5):  1498-1506.

 

Khan M, Amroliwalla F.  Flying status and coronary revascularization procedures in military aviators.  Aviat Space Environ Med. 1996; 67(11):  165-170.

 

Chaitman BR, Davis KB, Dodge HT, et al.  Should airline pilots be eligible to resume active flight status after coronary bypass surgery?: A CASS Registry study.  J Am Coll Cardiol.  1986; 8(6):  1318-1324.

 

Cutlip DE, Chhabra AG, Baim DS, et al.  Beyond restenosis: Five-year clinical outcomes from second-generation coronary stent trials.  Circulation.  2004; 110:  1226-1230.

 

Dargie HJ. First European workshop in aviation cardiology.  Late results following coronary artery bypass grafting.  Eur Heart J.  1992; 13(suppl H):  89-95.

 

Goy J, Eekhout E, Moret C, et al.  Five-year outcome in patients with isolated proximal left anterior descending coronary artery stenosis treated by angioplasty or left internal mammary artery grafting.  Circulation.  1999; 99:  3255-3259.

 

Henderson RA, Pocock SJ, Clayton TC, et al.  Seven-year outcome in the RITA-2 trial: Coronary angioplasty versus medical therapy.  J Am Coll Cardiol.  2003; 42(7):  1161-1170.

 

Hueb WA, Soares PR, de Oliveira SA, et al.  Five-year follow-up of the medicine, angioplasty, or surgery study (MASS).  Circulation.  1999; 100(Suppl II):  107-113.

 

Joy, Michael. Cardiovascular disease.  In:, Ernsting’s Aviation Medicine, 4th ed. London: Hodder Education, 2006; 568-679.

 

Kruyer WB.  Cardiology.  In: Rayman RB, ed.  Clinical Aviation Medicine, 4th ed.  New York: Graduate Medical Publishing, LLC, 2006; 162-168.

 

Kruyer, WB, Waddell, GA, Coronary artery revascularization in military aviators and suitability for return to flying. Minutes of the Aerospace Medicine Corporate Board; Oct 8-9, 2008; Hurlburt Field, FL.

 

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; 323-331.

 

Moorman DL, Kruyer WB, Jackson WG.  Percutaneous transluminal coronary angioplasty (PTCA): Long-term outcome and aeromedical implications.  Aviat Space Environ Med.  1996; 67(10):  990-996.

 

Webb-Peploe MM.  Second European workshop in aviation cardiology.  Late outcome following PTCA or coronary stenting: Implications for certification to fly.  Eur Heart J.  1999; 1(suppl D):  D67-D77.

 

 

 

Prepared by Drs. George Waddell, William Kruyer and Dan Van Syoc

Date: September 26, 2010