What is the clinical difference between a cardiovascular risk assessment and a cardiac stress test?

A cardiovascular risk assessment is a forward-looking clinical calculation: it uses current biomarkers (ApoB, Lp(a), hs-CRP, blood pressure, family history, age, smoking status) to estimate the probability of a cardiovascular event in the next 10 years and to identify modifiable risk factors. The Audit provides this. A cardiac stress test is a diagnostic procedure: it tests whether existing coronary artery disease is producing detectable ischemia under exercise conditions. It is used when symptoms (chest pain, exertional dyspnea, syncope) or high-risk findings (CAC above 300, prior MI) make the question of significant coronary stenosis clinically relevant.

In a man 35–55 with no symptoms and no known CAD, a cardiovascular risk assessment is the appropriate first step. A stress test in this population has poor sensitivity for detecting early or moderate plaque, it is designed to catch hemodynamically significant stenosis (typically above 70%), not the 40–50% stenosis that may be the current state of a man who will have an MI in three years. The CAC score is more useful than a stress test for asymptomatic risk stratification in this age group because it directly images calcified plaque, which is the substrate for future events, rather than waiting for the plaque to narrow the lumen enough to be detectable on stress imaging.

What to do: If your physician orders a stress test for cardiovascular risk assessment in an asymptomatic man with no prior events, ask whether a CAC score would be more informative for your specific risk profile.

For the full picture, read The Mogire Cardiac Risk Audit.