New guidelines for screening cardiovascular risk in adults with no symptoms

In case you didn't have a chance to notice, the practice guidelines for assessing cardiovascular risk just published by the American College of Cardiology Foundation/American Heart Association Task Force in the journal Circulation and the Journal of the American College of Cardiology offer some useful pointers that will spare money and duress by identifying as unnecessary some tests that have become popular. Laboratory markers of cardiovascular disease have expanded in recent years and not all bear up to thorough scrutiny. The authors state:

"For any new risk marker to be considered a useful candidate for risk prediction, it must, at the very least, have an independent statistical association with risk after accounting for established readily available and inexpensive risk markers. It should be based on studies that include large numbers of outcome events and with rigorous assessments that include analysis of the calibration, discrimination, and reclassification of the predictive model."

In other words, a new risk marker under consideration must add value to the already existing and inexpensive tests available, and be validated as rigorously as possible. A few choice comments:

• Global risk scores (e.g., Framingham or Reynold’s) and family history of atherothrombotic disease should be assessed in all asymptomatic adults.
• In the absence of inflammatory disorders, C-reactive protein may be useful in men 50 years and women 60 years and older with a low-density lipoprotein cholesterol <130 mg/dl...
• Lipoprotein-associated phospholipase A2 may be useful in intermediate-risk persons.
• There is no evidence in support of the following: measurement of lipoproteins, apolipoproteins, particle size and density; genomic testing; CAC [coronary artery calcium] score in very low-risk persons; coronary computed tomography angiography or magnetic resonance imaging of plaque for risk assessment; or stress echo or stress MPI in low- or intermediate-risk asymptomatic adults.

Clinicians will want to peruse the complete report. Personally I am glad to see the inclusion of Lipoprotein-associated phospholipase A2 (Lp-PLA2) because this is produced specifically in inflamed vulnerable plaque, making it a 'functional' assessment.