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 therefore required to undergo periodic cardiac screening, including exercise-testing. Unfortunately, this modality lacks diagnostic accuracy for relevant coronary artery disease (CAD) in low-risk populations similar to military aircrew. In contrast, cardiac CT, including 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 intervention.
The aim of this study is to assess the value of cardiac CT for clinically and “aeromedically” relevant CAD in asymptomatic Dutch military aircrew aged ≥ 40 years in comparison to the current cardiac screening protocol including exercise ECG.
Design This is a prospective, single-center, cohort study of 214 RNLAF aircrew. All asymptomatic aircrew ≥40 years were asked to undergo a voluntary cardiac CT following routine aeromedical examination including exercise ECG. Prevalence and severity of CAD will be described according to the CAD-RADS system, including 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%).
Results CCTA and CACS data for 213 subjects was analyzed, 98% of inclusions was male. Mean age was 48.5 years old. A CACS of 0 was observed in 135 subjects (63.3%). There was no stenosis in 122 subjects (57%). A stenosis of ≥50% was observed in 8 subjects. A CACS ≥100 AU was observed in 22 subjects. An aggregate stenosis of ≥120% was observed in 22 subjects.