Cardiac Health for Astronauts: Coronary Calcification Scores and CRP as Criteria for Selection and Retention

Hamilton DR, Murray JD, Ball CG. Cardiac health for astronauts: coronary calcification scores and CRP as criteria for selection and retention. Aviat Space Environ Med 2006; 77:377–387.



Due to the limited treatment and return capabilities of most space vehicles, an in-flight cardiac event could result in significant mission impact or even failure. The current literature supports including electron-beam computed tomography (EBCT) and highly selective C-reactive protein (hsCRP) for diagnosis of coronary artery disease (CAD) in asymptomatic, low-pretest probability cohorts. This paper will examine the issues surrounding adding these tests to astronaut retention and selection algorithms. An evidenced-based literature review was performed and consensus obtained from subject-matter experts to create novel cardiac screening algorithms for astronaut applicants and the current astronaut corps. The main focus of this paper is to derive an evidenced-based approach for improving the diagnosis of significant CAD using EBCT and hsCRP testing. The recommended initial astronaut selection and long-duration mission assignment screening algorithms use EBCT-derived calcium scores and serum hsCRP levels to screen for CAD and predict individual cardiac risk. The current medical evidence is compelling for the international space medicine community to consider: 1.) Astronaut candidates with a coronary artery calcium score > 0 should be disqualified from initial selection; 2.) Astronauts with a coronary artery calcium score > 100 should be disqualified from selection for long-duration missions; 3.) Elevated hsCRP is a reliable risk factor for helping predict future cardiac events that should warrant primary prevention but not necessarily medical disqualification.