[Evaluation of the prognostic value of cardiac troponin i in patients with unstable angina].
OBJECTIVE
The purpose of this study was to evaluate the in-hospital and follow-up prognostic value of cardiac troponin I in patients admitted in the Coronary Care Unit and discharged with the diagnosis of unstable angina.


METHODS
118 patients were admitted in the Coronary Care Unit, discharged with the diagnosis of unstable angina with a follow-up of 13.5 months. Cardiac Troponin I (cTnI) was measured on admission, 4 and 12 hours later. For the purposes of the study, we chose a cut-off value of 0.4 ng/mL as the minimal acceptable concentration of cTnI. The patients were divided in two groups: Group A (n = 82) if all measurements with cTnI < or = 0.4 ng/mL and Group B (n = 36) if any measurement with cTnI > 0.4 ng/mL. In both groups, multiple coronary events during hospitalisation and follow-up were evaluated: death; acute myocardial infarction; angina; hospitalisation; coronary surgery or angioplasty; and also the severity of coronary artery disease and the number of patients without coronary events. The results were compared by the Student's unpaired t-test and by chi-square test.


RESULTS
Age, sex and vascular risk factors were similar in both groups. There was a statistically significant increase in angina and coronary surgery with increasing levels of cardiac troponin I (Group B) (13 vs 5, p < 0.0001), multiple vessel disease (16 vs 18, p < 0.0008) and myocardial infarction (12% vs 0%, p < 0.03). Sixty patients had no coronary events in Group A compared to thirteen in Group B (p < 0.0001). There were no significant differences between the groups with respect to hospitalisation and angioplasty (17% in Group B vs 7% in Group A) and death (3% vs 0%).


CONCLUSIONS
In this population with unstable angina, cardiac troponin I level greater than 0.4 ng/mL measured in the 12 hours after admission provides useful prognostic information. It permits the early identification of patients with an increased risk of in-hospital and follow-up cardiac events and could be correlated with the severity of coronary artery disease.
Fontes
J P
JP
Serviço de Cardiologia, Centro Hospitalar de Gaia.
Araújo
D
D
Dias
A
A
Almeida
F
F
Gonçalves
M
M
Simões
L
L
Ribeiro
V G
VG
D000789:Angina, Unstable / Q000378:metabolism*; D005260:Female; D005500:Follow-Up Studies; D006760:Hospitalization; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000737:chemistry*; D011379:Prognosis; D019210:Troponin I / Q000032:analysis*
D019210:Troponin I