CTA limited in predicting adverse cardiac events post non-cardiac surgery

May 31, 2015 - Although major cardiac complications after non-cardiac surgery are common,1 the ability to accurately predict these events in individual patients using coronary computed tomographic angiography (CTA) is limited and a supplemental method may enhance risk prediction, suggests a recent study.2

The objective of the study was to determine if CTA enhances prediction of perioperative risk in patients before non-cardiac surgery and to assess the preoperative coronary anatomy in patients who experience a myocardial infarction after non-cardiac surgery.

The prospective cohort study evaluated 955 patients with, or at risk of, atherosclerotic disease who underwent non-cardiac surgery. The primary outcome was cardiovascular death and non-fatal myocardial infarction within 30 days after surgery. The independent variables were scores on the revised cardiac risk index and findings on coronary computed tomographic angiography.

The results found that coronary CTA would have resulted inappropriately in 98 net patients receiving a higher risk estimation, among the 923 patients who would not have experienced the primary outcome.

Image source: HeartView Global Foundation. http://heartviewglobal.org/coronary-cta.aspx

The authors concluded that while findings on coronary CTA can improve estimation of risk for patients who will experience perioperative cardiovascular death or myocardial infarction, findings are more than five times as likely to lead to an inappropriate overestimation of risk among patients who will not experience these outcomes. Since clinical practice guidelines recommend assessment of preoperative risk, beginning with clinical risk indices, which underestimate the risk of major perioperative complications, the authors suggest using a supplemental method to enhance risk prediction.  

Source:

1. Devereaux PJ, Chan MT, Alonso-Coello P, et al. Vascular Events In Noncardiac Surgery Patients Cohort Evaluation Study I, Association between postoperative troponin levels and 30-day mortality among patients undergoing noncardiac surgery. JAMA2012;307:2295-304.

2. Sheth T, Chan M, Butler C, et al. Prognostic capabilities of coronary computed tomographic angiography before non-cardiac surgery: prospective cohort study. BMJ 2015; 350 doi: http://dx.doi.org/10.1136/bmj.h1907.