Cardiac troponin I in acute coronary ischemic syndromes. Epidemiological and clinical correlates.
The present study was aimed to investigate the variability of cardiac troponin I (cTnI) in the first week of acute myocardial infarction (AMI) course with regard to some epidemiological and clinical parameters and in patients with non-AMI acute coronary ischemic disease. Serum cTnI was assayed in 82 patients, 42 affected with AMI and 40 with non-AMI acute coronary ischemic disease, on admission in coronary care unit, within 6 h after the onset of symptoms, and, in AMI group, on 24 and 48 h and 7th day of illness course. cTnI is increased within the first 6 h, remaining above normal until 7th day. However, some distinctive features in the subgroups scheduled for this study are present. (1) The mean values of cTnI in AMI patients who died, >60 years old and with anterolateral necrosis are constantly higher than in survivors, <60 years old and with inferoposterior necrosis, respectively. (2) The cTnI concentration is already returned in normal range at 7th day of illness course in survivors and in patients with inferoposterior AMI. (3) The 24-h peak level of cTnI is significantly higher in fibrinolysed than in patients who didn't undergo fibrinolysis. (4) A direct correlation between the cTnI value and the Killip class is present either in the whole group or in any subset of patients and the progressive decrease of the cTnI concentration along the AMI course doesn't occur in Killip>2 group. (5) cTnI is higher in unstable than in stable anginous patients and normal subjects but not in stable angina with respect to healthy controls.


CONCLUSIONS
(1, 2) The less increase and the early return in normal range of cTnI serum levels which occur in AMI subgroups with a better prognosis could be regarded as favourable prognostic signs. (3) The persistent higher values of cTnI in fibrinolysed subjects being associated with the angiographic finding of patent coronary arteries, it can be suggested that the large and persistent relase of cTnI from myocardium represents a reliable biochemical marker following the wash-out associated to a successful reperfusion. (4) The persistent increase of cTnI in AMI patients with advanced Killip class suggests that the high cTnI values are not only a strong index of myocardial necrosis but also of ongoing myocyte injury and hemodynamic impairment predictive of poor outcome. (5) The hypothesis can be reasonably advanced that the higher values of cTnI in unstable angina are due to focal areas of myocardial necrosis undetectable by the conventional serum markers or to a clinically silent AMI occurred in the week or so before in-hospital admission.
Lucia
P
P
II Medical Clinic, University 'La Sapienza', Rome, Italy.
Coppola
A
A
Manetti
L L
LL
Sebastiani
M L
ML
Colliardo
A
A
Cerroni
F
F
De Martinis
C
C
Strappini
P M
PM
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000789:Angina, Unstable / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000188:drug therapy; D017202:Myocardial Ischemia / Q000097:blood*; D011379:Prognosis; D012680:Sensitivity and Specificity; D015912:Thrombolytic Therapy; D019210:Troponin I / Q000097:blood*
D019210:Troponin I