Post-exercise high-sensitivity troponin T levels in patients with suspected unstable angina.

Gaetano Antonio Lanza,Annalisa Potenza,Erica Mencarelli,Antonio De Vita,Silvia Baroni,Laura Manfredonia,Filippo Crea,Chiara Cordischi,Veronica Melita,Antonio Bisignani,Antonio Tota,Giuseppa Caccamo,Mirca Antenucci,Maurizio Gabrielli,Giuseppe Vitale,Filippo Sarullo,Francesco Franceschi,Silvia Cardone,Carmine Pizzi

doi:10.1371/journal.pone.0222230

Abstract

BackgroundPrevious studies showed that troponin blood levels may increase after exercise. In this study we assessed whether, among patients admitted with suspected unstable angina, the increase in high-sensitive troponin T (hs-TnT) levels after exercise stress test (EST) might help identify those with obstructive coronary artery disease (CAD) and predict symptom recurrence during short term follow-up.MethodsMaximal treadmill EST was performed in 69 consecutive patients admitted to the emergency room with a suspicion of unstable angina (acute chest pain but confirmed normal serum levels of cardiac troponins) was measured before and 4 hours after EST. Coronary angiography was performed in 22 patients (32.8%).Resultshs-TnT increased after EST compared to baseline in the whole population (from 0.84±0.65 to 1.17±0.87 ng/dL, p<0.001). The increase was similar in patients with positive (n = 14) and negative (n = 55) EST (p = 0.72), and was also similar in patients with (n = 12) and without (n = 10) obstructive CAD at angiography (p = 0.91). The achievement of a heart rate at peak EST ≥85% of that predicted for age was the variable mainly associated with the post-EST hs-TnT increase at multivariable linear regression analysis (p = 0.005). The change after EST of hs-TnT did not predict the recurrence of symptoms or readmission for chest pain at 6-month follow-up.ConclusionsOur data show that hs-TnT increased after EST in patients with suspected unstable angina, which seemed largely independent of most clinical and laboratory variables. Thus, hs-TnT assessed after EST does not seem to be helpful to identify patients with obstructive CAD in this kind of patients.

Highlights

The detection of increased blood levels of troponins has become the reference marker for the diagnosis of acute myocardial infarction [1,2]
The achievement of a heart rate at peak exercise stress testing (EST) 85% of that predicted for age was the variable mainly associated with the postEST high-sensitive troponin T (hs-TnT) increase at multivariable linear regression analysis (p = 0.005)
Our data show that hs-TnT increased after EST in patients with suspected unstable angina, which seemed largely independent of most clinical and laboratory variables

Summary

Introduction

The detection of increased blood levels of troponins has become the reference marker for the diagnosis of acute myocardial infarction [1,2]. Some studies showed that troponins may increase following myocardial ischemia, in the absence of cell necrosis [5,6,7,8,9,10,11] The latter data suggested the possibility that a significant increase of troponins after stress testing might increase the diagnostic yield for obstructive coronary artery disease (CAD) [12]. Instead, investigated the response to exercise of troponins in patients with a suspicion of acute coronary syndrome (ACS) In these patients the detection of ischemic abnormalities at the electrocardiogram (ECG) and/or increased levels of troponins is usually an indication to admission and invasive management [18,19,20]. In this study we assessed whether, among patients admitted with suspected unstable angina, the increase in high-sensitive troponin T (hs-TnT) levels after exercise stress test (EST) might help identify those with obstructive coronary artery disease (CAD) and predict symptom recurrence during short term follow-up

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