Cardiovascular risk assessment

Considerations

Cardiovascular events may lead to medical incapacitation. Thus an estimation of the probability of an applicant suffering a cardiovascular (CV) event is an essential part of the assessment. Such estimation is based on community prevalence of ischaemia.

The General Direction, Timetable for Routine Examinations, prescribes when a formal cardiovascular risk assessment is required to be performed.

GD: Timetable for Routine Examinations [PDF 500 KB]

The General Direction, Examinations Procedures, prescribes how a formal cardiovascular risk assessment should be performed.

The General Direction, Examination Procedures, requires that a 5-year CV risk estimate of 10% or above requires exclusion of cardiac ischaemia.

GD: Examination Procedures [PDF 1.6 MB]

The information sheet, Cardiovascular risk, provides explanations for applicants. MEs may find the information useful.

Medical information sheet 007: Cardiovascular risk [PDF 626 KB]

Note: An applicant with a history of peripheral vascular disease, cerebrovascular accident or cardiovascular disease automatically falls in a high 5-year cardiovascular risk category, i.e. well above 10%.

Stress ECG (or ETT)

In general a symptom limited, unequivocally negative, stress ECG reaching a good level of exercise (end of stage 3, i.e. 9 minutes or above of the Bruce protocol, 85% of maximum predicted, 10 METS) is acceptable evidence of absence of ischaemia.

When a stress ECG cannot be accomplished by exercise, a pharmacological stress test may be acceptable. The reason for undertaking such test must be explained and considered.

When required, the CAA acknowledged validity of such test is:

• One year in the case of Class 1 and 3 applicants;
• Two years in the case of Class 2 applicants.

Part 5 of this manual provides CAA protocols for the various tests and their reporting.

The relevant protocol should be printed and given to the applicant to pass on to the practitioner conducting the test. This is to ensure a high quality stress is performed, that is useful for aviation public safety purposes.

Calcium scoring

CT Coronary Artery Calcium Scoring (CT Calcium Scoring) is a relatively inexpensive test. Published research confirms the powerful prognostic value of a zero Agatston score.

For the purpose of the cardiovascular risk assessment, a Calcium Score of zero will allow to reassess the cardiovascular risk as being lower than suggested by the method prescribed in the GD 'Examination procedures'. A Calcium score of zero can be relied upon for several years.

Currently, until changes are made to several documents, this policy can only be implemented via the statutory process provided by sections 27B(2) and (3) of the Civil Aviation Act flexibility (Accredited Medical Conclusion).

At this point of time CAA will accept an Agatston score of zero as remaining valid for a period of five years.

So, currently:

1. If an applicant returns an elevated 5-year Cardiovascular Risk Estimation (10% or greater) then a CT Calcium Score may be undertaken instead of an Exercise Stress ECG;
2. If the CT Calcium Score is zero the application may be progressed via the statutory flexibility process, by applying for the identification of AMC experts;
3. If the CT Calcium Score is non-zero then the usual workup, to exclude reversible myocardial ischaemia, is required.

This process is also shown here in diagram form.

Other cardiac tests

In some cases a stress ECG is not sufficient to exclude ischaemia because of an insufficient level of exercise, a non-unequivocally negative or a positive tracing.

A stress echocardiogram or myocardial perfusion scan can be undertaken to more reliably exclude ischaemia. Other reasons to undertake such investigations may be the applicant’s cardiovascular history or a previous equivocal stress ECG. In doubt MEs should contact the CAA.

The role of other investigative modalities has not been clearly established in the context of aeromedical certification. MEs should consult with CAA whenever an applicant presents to them having undergone any other such investigations, including coronary angiography or CT coronary angiography.

Information to be provided

See comments about CT Calcium Scoring that may affect the following list.

• ECG, blood lipids and blood glucose or HbA1c, in accordance with the GD 'Timing for Routine Examinations';
• Cardiovascular risk assessment in accordance with the GDs 'Timing of Routine Assessments' and 'Examination Procedures';
• In the case of a Class 1or 3 applicant: Annual stress ECG (or test of higher sensitivity / specificity as appropriate) when ischaemia needs excluding under the GD 'Examination Procedure' - Full ECG tracings and report to be provided to CAA;
• In the case of a Class 2 applicant: Two yearly stress ECG (or test of higher sensitivity / specificity as appropriate) when ischaemia needs excluding under the GD 'Examination Procedure' - Full tracing and report to be provided to CAA;
• Tests and reports as may have been advised by CAA in the case of an applicant with a history of cardiovascular disease. Such applicants often require annual specialist review and exercise testing of some kind.

Disposition

• An applicant with an estimated 5-year CV risk below 10 % may be assessed as not having a condition that is of aeromedical significance;
• An applicant with an estimated 5-year CV risk of 10 % or above, who has provided an unequivocally negative stress ECG, may be assessed as having a condition that is not of aeromedical significance. The test must been to a good level of exercise i.e. at least end of stage 3 of the Bruce protocol, 85% of maximum predicted heart rate or 10 METS, and be free of symptoms and signs of ischaemia;
• An applicant who has undergone Calcium Scoring, with a zero score, may be considered, under the flexibility process (i.e. AMC), as having a cardiovascular risk of less than 10% at five years;
• An applicant with a history of cardiac ischaemia, cerebrovascular or peripheral vascular disease should be assessed as having a condition that is of aeromedical significance and should be considered under the flexibility process.