Taking post-arrest patients to cardiac catheterization improves outcomes – as long as they have a cardiac occlusion as the underlying etiology of their arrest. Otherwise, you’re simply delaying the diagnosis and treatment of alternative causes, as well as post-arrest ICU-level care. Therefore, if there is some clinical feature that can be identified on initial Emergency Department evaluation that predicts a coronary occlusion, that would be of great value.
So, this is a retrospective analysis of a prospective registry of out-of-hospital arrests from Paris, where much of the post-arrest catheterization work has been done. And, unfortunately, there isn’t any useful association – 92% of their patients had elevated troponin on initial evaluation. There was a nonsignificant trend towards higher troponin levels in patients with coronary occlusion, but even at their “optimum” cut-off of 4.66ng/mL, the sensitivity and specificity were nearly coin-flip at 66% each. A troponin of 31ng/mL was required for 95% specificity.
ST-segment elevation, incidentally, was more predictive of a coronary occlusion – OR 10.19 (CI 5.39 to 19.26).
“Can early cardiac troponin I measurement help to predict recent coronary occlusion in out-of-hospital cardiac arrest survivors?”
http://www.ncbi.nlm.nih.gov/pubmed/22488008