Thromboembolic disorders and use of anticoagulation

Guidance on certification of applicants with a diagnosis of deep vein thrombosis, pulmonary embolism or using anticoagulation medication.

Venous thromboembolic disorders

Applicants with a diagnosis of venous thromboembolism (deep vein thrombosis and pulmonary embolism), should be assessed as unfit. These may be provoked or unprovoked.

An apparently unprovoked venous thromboembolic disorder should be screened appropriately for the possibility of undiagnosed cancer and for underlying thrombophilia, as appropriate and guided by haematology.

Pulmonary embolism may be categorised as non-massive / low risk, sub-massive / intermediate risk, and massive / high-risk. All cases (Class 1, 2 and 3) where the presentation was either sub-massive or massive should undergo cardiology assessment. All cases regardless of risk stratification should undergo respiratory review.

Assessment for certification may be undertaken, subject to satisfactory receipt of reports (including haematology if appropriate), after a period of stable anticoagulation (see section on anticoagulation medication) by a Civil Aviation Authority (CAA) medical assessor (Class 1 and 3) or by an aeromedical examiner (AME) (Class 2) for the following:

• Class 1 OML
• Class 2 unrestricted
• Class 3 unrestricted

Arterial thromboembolic disorders

This excludes cerebrovascular, coronary artery and retinal disease (see separate guidance for each). Appropriate screening should be undertaken in the absence of vascular risk factors.

Assessment for certification may be undertaken, subject to satisfactory receipt of reports (including haematology if appropriate), after a period of stable anticoagulation (see section on anticoagulation medication) by a CAA medical assessor (Class 1 and 3) or by an AME (Class 2) for the following:

• Class 1 OML
• Class 2 unrestricted
• Class 3 unrestricted

Anticoagulation medication

Acceptable direct oral anticoagulants (DOACs) are dabigatran, rivaroxaban, edoxaban and apixaban.
Common indications for anticoagulation include:

• deep vein thrombosis / pulmonary embolism: see previous guidance material
• atrial fibrillation: see the atrial fibrillation flow chart and guidance material
• cardiac valve replacement (warfarin only):
  
  • the target international normalised ratio (INR) following valve replacement and other co-morbidities should be considered
  • certification is permitted after an aortic valve replacement but not a mitral valve replacement due to complication risks (see the aortic valve replacement flow chart)

In all cases of anticoagulation (Class 1, 2 and 3) certification is possible provided the following:

• the applicant has recovered from the underlying condition or the condition has been stabilised and does not in itself preclude flying
• the total incapacitation risk of the underlying condition and anticoagulation (including haemorrhagic risk) is acceptable for the level of certification sought

Assessment for certification may be undertaken, subject to satisfactory reports, by a CAA medical assessor (Class 1 and 3) or AME (Class 2) for the following:

• Class 1 OML
• Class 2 unrestricted (in some cases, restricted Class 2 certification may be appropriate, see the aortic valve replacement flow chart)
• Class 3 unrestricted

Warfarin requirements (Class 1, 2 and 3)

The INR range should be determined clinically, and the INR should be demonstrated to be within the target range for 6 months (at least 5 INR values documented, of which at least 4 are within the INR range). At least 2 monthly INR testing should be continued on an ongoing basis. If the INR varies considerably within the target range on the initial readings, a longer period of surveillance may be required.

Applicants treated with warfarin are required to measure their INR on a ‘near patient’ testing system (such as CoaguChek S) 12 hours prior to flying / controlling and only fly / control if the INR is within the target range. The INR should be recorded in their logbook. The logbook should be reviewed at each medical certificate revalidation examination.

DOAC requirements (Class 1, 2 and 3)

Applicants taking DOACs should be free of side effects for a period of 3 months prior to fitness reassessment. Appropriate blood monitoring should be checked and normal.

LAPL pilots

A shorter period of stabilisation (6 weeks for DOACs and 4 months for warfarin) may be acceptable provided there are no side effects and there is reliable evidence of INR stability in pilots taking warfarin. In DOAC use, appropriate blood monitoring should be checked and normal.

Cardiology MED.B.010 Class 1

Anticoagulant Therapy

Certification to Class 1 OML level is possible on anticoagulant therapy.

Cardiology MED.B.010 Class 2

Anticoagulant Therapy

Certification to unrestricted Class 2 level is possible on anticoagulant therapy.