Risk assessment beyond traditional risk factors

• Coronary Artery Calcium Score

  AI search- role of CTCA and CAC in pilots

  CTCA and CAC in pilots

   

  This is a complex area in aviation medicine, and regulations from bodies like the Federal Aviation Administration (FAA) and the European Union Aviation Safety Agency (EASA) are continually evolving, particularly with the rise of advanced cardiac imaging.1

  For a cardiologist assessing a pilot's fitness to fly, the data and guidelines focus heavily on quantifying the plaque burden and the risk of sudden incapacitation (like a heart attack or a major adverse cardiac event, MACE).2

  Here's a breakdown of the key data points and how plaque burden is assessed and used:

   

  1. Plaque Quantification and Imaging Modalities

  The assessment of plaque burden in pilots largely relies on two non-invasive imaging techniques:

  • Coronary Artery Calcium Score (CACS):
  • This is a non-contrast CT scan that quantifies calcified plaque, expressed as an Agatston score.3
  • Data Use: CACS is a strong, independent predictor of future MACE and is often used for initial risk stratification in asymptomatic aircrew, especially those over 40.
  • Relevance: A CACS ≥100 Agatston units is frequently cited in aviation medicine as a threshold for "aeromedically relevant CAD" (AR-CAD) or a higher risk category, often prompting further, more detailed testing like a CCTA. A higher CACS correlates with a higher total plaque volume and a greater likelihood of significant Coronary Artery Disease (CAD).4
  • Coronary Computed Tomography Angiography (CCTA):
  • This contrast-enhanced CT scan provides detailed visualization of both calcified and non-calcified plaque, and the degree of luminal stenosis.
  • Data Use: CCTA allows for the calculation of the total plaque burden (e.g., total plaque volume, segment involvement score) and the identification of High-Risk Plaque (HRP) features (e.g., positive remodeling, low-attenuation plaque, spotty calcification), which are associated with plaque vulnerability and a higher risk of acute events.
  • Relevance: CCTA is considered superior to CACS alone because it can detect non-calcified plaque and HRP features, which are critical for assessing a pilot's acute risk.

  2. Regulatory and Risk-Based Thresholds

  Aviation authorities aim for a very low annual risk of sudden incapacitation, often cited as 5<1% per annum for professional aircrew (e.g., dual-pilot operations).6 Plaque burden metrics are used to help estimate this risk.7

  • Stenosis and Ischemia:
  • The primary disqualifier is hemodynamically significant CAD, typically defined as a stenosis ≥70% in a major vessel or ≥50% in the left main coronary artery, or a Fractional Flow Reserve (FFR) (or CT-FFR) <0.80, indicating ischemia. Aircrew with this level of disease are generally grounded until successful revascularization (PCI or CABG) is performed, followed by a post-procedure grounding period and successful non-invasive testing.
  • Aggregate Plaque Burden (Non-Obstructive Disease):
  • For non-obstructive CAD (lesions 8<50%), guidelines increasingly use a measure of total plaque burden to assess overall risk.9
  • Aggregate Stenosis: Some guidelines define a "severe" aggregate stenosis (e.g., an sum of all individual lesion stenoses) 10≥120% as a grounding criterion, even if no single lesion is hemodynamically significant.11 This recognizes that overall disease burden drives long-term risk.
  • CCTA Plaque Volume: While not universally standardized in every regulatory document, research in aviation medicine is moving toward incorporating CCTA-derived plaque volume (total, calcified, and non-calcified) and the presence of HRP features into the risk assessment for return-to-flight decisions.

  3. Management and Return to Flight

  For aircrew with confirmed CAD (including significant plaque burden, even if non-obstructive), a return to flying duties often requires:

  1. Aggressive Risk Factor Modification: Mandatory control of factors like lipids, blood pressure, and diabetes, often with mandated medication (e.g., statins, regardless of baseline LDL-C).12

  2. Residual Disease Acceptance: The aircrew must have no residual hemodynamically significant disease and an acceptable residual disease burden (e.g., not exceeding the aggregate stenosis thresholds).

  3. Operational Restrictions: Pilots returning to flight may be restricted to dual-pilot operations and/or non-high-performance aircraft to mitigate the remaining risk.13
  4. Mandatory Follow-up: At a minimum, annual follow-up with a cardiologist and a routine non-invasive cardiac evaluation is typically required.14

  In summary, plaque burden, as assessed by CACS and especially CCTA (including stenosis, aggregate stenosis, and high-risk features), has become a central data point for the cardiologist to quantify the long-term and acute risk of sudden incapacitation and determine the pilot's fitness to fly within established safety thresholds.

   

  From

  https://gemini.google.com/app/21b3c282f2a0d02c?utm_source=app_launcher&utm_medium=owned&utm_campaign=base_all

   

   

  Impact of the recent advances in coronary artery disease imaging on pilot medical certification and aviation safety: current state and future perspective

  2025

  https://doi.org/10.1007/s10554-025-03380-3

   

  Management of established coronary artery disease in aircrew without myocardial infarction or revascularisation

  Heart 2018

  https://doi.org/10.1136/heartjnl-2018-313054

   

   

   

  The role of coronary artery calcium scoring in the prediction of coronary artery disease based on non-contrast non-cardiac chest CT scans in airline pilots

  https://doi.org/10.3389/fcvm.2025.1511358

  From <https://www.frontiersin.org/journals/cardiovascular-medicine/articles/10.3389/fcvm.2025.1511358/full>