Elevated troponin I levels in patients with acute coronary syndrome without ST elevation are associated with increased complexity of the culprit lesion

INTRODUCTION: The prognosis in patients with acute coronary syndrome without persistent ST segment elevation (NSTEACS) differs depending on cardiac troponin levels. Clinical practice guidelines published by the Spanish Society of Cardiology and the ACC/AHA consider patients with NSTEACS and markedly elevated troponin levels as high risk patients. The aim of this study was to identify factors related to markedly elevated troponin I levels in NSTEACS. PATIENTS AND METHOD: We measured troponin I levels in 219 consecutive patients with NSTEACS and normal CK-MB values, and identified 2 groups: patients with markedly elevated troponin levels (more than 10-fold the normal upper limit), and patients with normal or slightly elevated troponin levels (less than a 10-fold increase above the normal limit). We also analyzed clinical and angiographic variables. Logistic regression was used to calculate age- and sex-adjusted associations for the main variables. RESULTS: Forty-one patients (19%) had markedly elevated troponin levels, and 178 (81%) showed normal or slightly elevated troponin I levels. Patients with markedly elevated levels had more frequently prolonged angina, class IIb angina, more severe ECG changes, a higher number of diseased vessels on coronary angiography, and greater severity of the culprit lesion. The culprit stenosis in these patients was more often characterized as ulcerated, showing visible thrombus, and excentric, bifurcated and irregular. Class IIIb angina (odds ratio [OR] = 3.1; CI 95%, 1.1-8.6), bifurcation (OR=6.04; CI 95%, 2.5-14.3), ulceration (OR=3.2; CI 95%, 1.07-9.7) and visible thrombus (OR=2.7; CI 95%, 1.1-6.3) in the culprit lesion were predictive factors associated with markedly elevated levels of troponin I independently of age or sex. CONCLUSIONS: Markedly elevated troponin I levels in patients with NSTEACS are associated with a more severe clinical presentation and increased complexity of the culprit lesion on coronary angiography.