title: Usefulness of the troponin-ejection fraction product to differentiate stress cardiomyopathy from ST-segment elevation myocardial infarction.
abstract: The presentation of stress cardiomyopathy (SC) with nonobstructive coronary artery disease mimics that of ST-segment elevation myocardial infarction (STEMI) due to coronary occlusion. No single parameter has been successful in differentiating the 2 entities. We thus sought to develop a noninvasive clinical tool to discriminate between these 2 conditions. We retrospectively reviewed 59 consecutive cases of SC at our institution from July 2005 through June 2011 and compared those with 60 consecutives cases of angiographically confirmed STEMI treated with primary percutaneous coronary intervention in the same period. All patients underwent acute echocardiography, and the peak troponin I level was determined. The troponin-ejection fraction product (TEFP) was derived by multiplying the peak troponin I level and the echocardiographically derived left ventricular ejection fraction. Comparing the SC and STEMI groups, the mean left ventricular ejection fraction at the time of presentation was 30 ± 9% versus 44 ± 11%, respectively (p <0.001), and the peak troponin I was 7.6 ± 18 versus 102.2 ± 110.3 ng/dl, respectively (p <0.001). The mean TEFP was thus 182 ± 380 and 4,088 ± 4,244 for the SC and STEMI groups, respectively (p <0.001). Receiver operating characteristic curve analysis showed that a TEFP value ≥250 had a sensitivity of 95%, a specificity of 87%, a negative predictive value of 94%, a positive predictive value of 88%, and an overall accuracy of 91% to differentiate a true STEMI from SC (C-statistic 0.91 ± 0.02, p <0.001). In conclusion, for patients not undergoing emergent angiography, the TEFP may be used with high accuracy to differentiate SC with nonobstructive coronary artery disease from true STEMI due to coronary occlusion.
authors.affiliation: Department of Cardiology, The Mount Sinai Heart Institute, Miami Beach, Florida. Electronic address: fonasci@gmail.com.
authors.forename: Francisco O
authors.initials: FO
authors.lastname: Nascimento
authors.affiliation: Department of Cardiology, The Mount Sinai Heart Institute, Miami Beach, Florida.
authors.forename: Solomon
authors.initials: S
authors.lastname: Yang
authors.affiliation: Department of Cardiology, The Mount Sinai Heart Institute, Miami Beach, Florida.
authors.forename: Maiteder
authors.initials: M
authors.lastname: Larrauri-Reyes
authors.affiliation: Department of Cardiology, The Mount Sinai Heart Institute, Miami Beach, Florida.
authors.forename: Andres M
authors.initials: AM
authors.lastname: Pineda
authors.affiliation: Department of Cardiology, The Mount Sinai Heart Institute, Miami Beach, Florida.
authors.forename: Vertilio
authors.initials: V
authors.lastname: Cornielle
authors.affiliation: Department of Cardiology, The Mount Sinai Heart Institute, Miami Beach, Florida.
authors.forename: Orlando
authors.initials: O
authors.lastname: Santana
authors.affiliation: Department of Cardiology, The Mount Sinai Heart Institute, Miami Beach, Florida.
authors.forename: Todd B
authors.initials: TB
authors.lastname: Heimowitz
authors.affiliation: Columbia University Medical Center, New York, New York; The Cardiovascular Research Foundation, New York, New York.
authors.forename: Gregg W
authors.initials: GW
authors.lastname: Stone
authors.affiliation: Department of Cardiology, The Mount Sinai Heart Institute, Miami Beach, Florida.
authors.forename: Nirat
authors.initials: N
authors.lastname: Beohar
mesh_terms: D000368:Aged; D017023:Coronary Angiography; D003937:Diagnosis, Differential; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology; D012372:ROC Curve; D012189:Retrospective Studies; D013318:Stroke Volume; D054549:Takotsubo Cardiomyopathy / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology; D019210:Troponin I / Q000097:blood*; D016277:Ventricular Function, Left / Q000502:physiology*
chemical_list: D019210:Troponin I