Troponin-T in unstable angina--a clinical and angiographic study.

ABSTRACT

OBJECTIVE: To examine the prognostic significance of Troponin-T in patients admitted with unstable angina and to study their angiographic morphology. DESIGN: Single centre, prospective study of in hospital events. SETTING: Intensive coronary care unit of a large municipal general hospital. SUBJECTS: 128 consecutive patients admitted with a diagnosis of unstable angina (Braunwald's classification). METHODS: Measurement of Troponin-T by qualitative assay at admission, coronary angiography between 5th to 7th day. MAIN OUTCOME MEASURES: In hospital adverse cardiac events--recurrent angina, new myocardial infarction or cardiac deaths. RESULTS: Fifty six (43.7%) patients had a positive test. The incidence of recurrent angina was significantly higher in the Trop-T positive group (57.1% vs 11.1%, p < 0.001). Six patients of this developed acute myocardial infarction subsequently whereas none of the patients in the Trop-T negative group developed acute MI (10.7% v/s 0%, p = 0.05). There were two deaths in the Trop-T positive group and none in the Trop-T negative group. 44 (78.5%) patients of the Trop-T positive group and 60 patients in the Trop-T negative group underwent coronary angiography. There was no significant difference in the incidence of single vessel disease (27.2% v/s 20%, p = NS) or multivessel disease (72.7% v/s 69.9%, p = ns). None of the patients with a positive Trop-T had normal coronary angiography whereas 6 patients in the Trop-T negative group had a normal coronary angiography (0% v/s 10%, p < 0.05). Patients with a positive troponin T test had a significantly higher incidence of type B lesions and a higher incidence of intracoronary thrombus. CONCLUSIONS: The in hospital outcome of Trop-T positive patients was significantly worse than patients with a negative test. Patients with a positive troponin T test had more complex coronary morphology and a higher incidence of intracoronary thrombus. We conclude that troponin-T can be used as a prognostic marker in patients with unstable angina.