IDIOPATHIC TROPONEMIA AFTER TRANSCAROTID ARTERY REVASCULARIZATION

ABSTRACT

SESSION TITLE Etiologies of Cardiovascular Disease Case Report Posters SESSION TYPE Case Report Posters PRESENTED ON 10/19/2022 1245 pm - 0145 pm INTRODUCTION: Troponin level (Tnl) is usually used as confirmation of acute myocardial infarction (AMI) and is a sensitive marker. It is usually increased within 2-3 hours after AMI. In most cases, increased in Tnl is associated with symptomatic chest pain, cardiac ischemia, chronic coronary syndromes, etc. It can also be elevated in other conditions without cardiac injuries, like critical illness COVID infection, septic shock, acute stroke and burns. CASE PRESENTATION A 72 y/o man with history of b/l internal carotid artery (ICA) stenosis (70% in R-ICA and 80-90% in L-ICA) underwent elective left trans-carotid artery revascularization (TCAR). He was transferred to ICU after an uneventful procedure, for monitoring. His history was significant for HTN, HLD, Meniere's disease, gout, prior CVA of L-frontal lacunar and R-PICA (posterior inferior cerebellar artery). Postop vitals BP 114/60 mmHg, HR 65, RR 16, O2 sat 98%. Tnl increased to 1.95 and then declined (normal 0 - 0.4 ng/ml). He was AAOx4, and asymptomatic. Post-op serial EKGs normal sinus rhythm with no ST/T wave changes. Echo EF 60%, normal biventricular size and function. LDL <70, A1C 5.9, normal TSH, no CPK elevation. Other labs normal, No new neurological deficits. He was continued on ASA, clopidogrel, metoprolol, amlodipine and lisinopril. His hospital stay was uneventful, and he was discharged on post-op day 3. DISCUSSION: Cardiac troponin complex has its distinct subunits according to their functions highly conserved Ca2+ binding subunit (cTnC);actomyosin ATPase inhibitory subunit and tropomyosin binding subunit. They play the pivotal role in regulating myocardial muscle contraction and relaxation and demonstrate as sensitive biomarkers for the myocardial injuries. Interestingly, there are many other causes that lead to increased cardiac troponin level without remarkable myocardial injuries or ischemia. Elevated Tnl after TCAR procedure can also be due to its surgical complication of a chance of hypoperfusion during the procedure. Our patient's surgery was uneventful. In one randomized controlled trial, it is stated that the risk of having CVA and AMI is higher in carotid endarterectomy compared to revascularization in patients with carotid artery stenosis. Our patient did not have any post-op complication, and only had an idiopathic elevation of troponin. CONCLUSIONS: The role of Tnl plays an important role in confirmation of myocardial infarction or ischemia but it can be idiopathic. Unpublished data from our institution revealed no increase in troponin s/p TCAR after uneventful procedures. This is the first reported case presenting with elevated troponin level without any pertinent positive findings (EKG changes/symptoms). Maybe in uneventful TCAR procedure troponin should not be ordered? Reference #1 Defilippi, C.R., Tocchi, M., Parmar, R.J., Rosanio, S., Abreo, G., Potter, M.A., Runge, M.S., & Uretsky, B.F. (2000). Cardiac troponin T in chest pain unit patients without ischemic electrocardiographic changes angiographic correlates and long-term clinical outcomes. Journal of the American College of Cardiology, 35 7, 1827-34. Reference #2 Gordon AM, Homsher E, Regnier M. Regulation of contraction in striated muscle. Physiol Rev. 2000 Apr;80(2)853-924. doi 10.1152/physrev.2000.80.2.853. PMID 10747208. Reference #3 Brott, T.G., Hobson, R.W., Howard, G., Roubin, G.S., Clark, W.M., Brooks, W., Mackey, A., Hill, M.D., Leimgruber, P.P., Sheffet, A.J., Howard, V.J., Moore, W.S., Voeks, J., Hopkins, L.N., Cutlip, D.E., Cohen, D.J., Popma, J.J., Ferguson, R.D., Cohen, S.N., Blackshear, J.L., Silver, F.L., Mohr, J.P., Lal, B.K., & Meschia, J.F. (2010). Stenting versus endarterectomy for treatment of carotid-artery stenosis. The New England journal of medicine, 363 1, 11-23. DISCLOSURES No relevant relationships by Moses Bachan No relevant relationships by Zin Min Htet No relevant relationships by Z nobia Khan No relevant relationships by Zin Oo