Screening for coronary artery disease using primary evaluation with coronary CTA in aviation medicine (SUSPECT): study design

Background: Sudden in-flight incapacitation of aircrew may cause an airplane crash. Important causes are major adverse cardiac events, such as myocardial infarction and sudden cardiac arrest. Aircrew of the Royal Netherlands Air Force (RNLAF) are required to undergo periodic cardiac screening, including bicycle exercise-testing. Unfortunately, this modality lacks diagnostic accuracy for relevant coronary artery disease (CAD) in low-risk populations similar to military aircrew. Cardiac CT, however, comprising Coronary Artery Calcium score (CACS) and coronary CT angiography (CCTA), is able to adequately detect (subclinical) CAD with high negative predictive values in low-risk populations and may provide opportunity for early interventions. Methods: This was a prospective, single-center, cohort study of 250 military aircrew. Asymptomatic aircrew ≥40 years are asked to undergo a voluntary cardiac CT following routine aeromedical examination. Prevalence and severity of CAD will be described according to the CAD-RADS system, including coronary artery calcium score (CACS) and high risk plaque features. The primary endpoint is relevant CAD, defined as a composite of a coronary stenosis ≥50% and/or CACS >100 Agatston Units. The secondary endpoint is ‘aeromedically significant CAD’, defined by national military regulations as a left main stenosis of >30%, any luminal stenosis ≥50%, and/or an aggregate coronary stenosis of ≥120%. Conclusions: The aim is to assess the value of cardiac CT for routine aeromedical screening in asymptomatic Dutch military aircrew aged ≥40 years, in comparison to the current cardiac screening protocol which includes an exercise ECG. Trial Registration: Clinical trial registered on clinicaltrials.gov number NCT05508893.