|Dr. Jim Min and Dr. David Maron talk about Coronary Artery Calcium and the ED
… We plan to cover 2 articles in this week’s update. Here are their comments in full.
Two recent articles in JACC talk about coronary artery calcium. Be sure to hear the summaries in Update 6 later this week. We asked the lead author, Dr. Jim Min and our own Dr. David Maron for their opinions about this. One of these studies would seem to support and one call into question the following recommendation of the American College of Cardiology and American Heart Association that states: �For the symptomatic patient, exclusion of measurable coronary calcium may be an effective filter before undertaking invasive diagnostic procedures or hospital admission. Scores <100 are typically associated with a low probability (2%) of abnormal perfusion on nuclear stress tests, and 3% probability of significant obstruction (= 50% stenosis) on cardiac catheterization.� It seems both the cardiologists we spoke to are of the same mind, however.
Keeping Up: “In JACC this week, you found that progression of CAC score from zero to > 0 took an average of four years. This study was done on asymptomatic patients. If a symptomatic patient comes to the ED, has negative serial ECGs and biomarkers, and a CAC score of zero within the past four years, would you feel comfortable sending that person home without further stress testing? An article in press in Annals of (see ) found that a CAC score of zero done at presentation in symptomatic patients safely predicts a very low risk group safe for discharge. Can the results of your study be applied in this way yet, or should we wait for ED-based studies that specifically address this question?”
Dr. Min: “I would caution folks to not extrapolate our findings to the ED acute chest pain patients, as prior studies have demonstrated a non-negligible rate of obstructive stenosis in these pts despite a zero calcium score (10-15%). I think that contrast-enhanced CT angiography would be more definitive, or else whatever is standard-of-care at the practicing site (e.g. nuclear stress testing).”
Dr. Maron: “A score of zero does not guarantee the absence of disease, so I would NOT rely on a CAC score of zero to discharge a patient (even though a score of zero has a great prognostic value). There are too many reports of people with zero scores who go on to have ACS that it is not reliable. I couldn�t say it better than this paper does [referring toGottlieb I et al. The Absence of Coronary Calcification Does Not Exclude Obstructive Coronary Artery Disease or the Need for Revascularization in Patients Referred for Conventional Coronary Angiography. J Am Coll Cardiol February 2010;55:627�34, which will be discussed this week in Update 6].
Looks like we need to be cautious about how we use coronary artery calcium scoring in the ED setting! Better listen to Update 6 coming up this week to hear both articles!