Musso P, Vernocchi A, Crippa A, Bajardi D, Ottello B, Pinnavaia A, Ronzani G, Bergandi G, Ravera A, Scrocca I
Divisione di Cardiologia, Ospedale Civile, Ivrea, Torino.
Minerva Cardioangiol. 1996 Apr;44(4):187-95.
Unstable angina implies high risk of myocardial infarction and sudden death. Increased levels of cytoplasmatic enzymes and proteins (creatine phosphokinase, MB creatine phosphokinase troponin T, etc.) were described in unstable angina, providing information about incoming major coronary events. Cardiac troponin I (cTn-I) is a structural protein inhibiting the actinomyosine ATPase; it is only found in myocardial cells. Serum titration of cTn-I has been recently introduced into clinical practice as a sensitive and specific marker of myocardial cellular necrosis.
The aim of our prospective study was to assess the presence of cTn-I in blood samples of patients with unstable angina and no signs of myocardial necrosis. Furthermore we intended to test the possible use of cTn-I in unstable angina as a prognostic marker of major coronary events on short and middle term.
We studied 33 consecutive patients admitted to our CCU for unstable angina. According to unstable angina Braunwald's classification, 6 patients were included in the first class, 4 patients in the second class and 23 patients in the third class. We excluded patients with acute or recent myocardial infarction. Blood samples of all patients were obtained at the time of CCU admission and every eight hours in the first and second day. Serum cTn-I titration was performed with the sandwich immunoenzymometric method, recently introduced by Diagnostic Pasteur. Two months follow-up was carried out in order to survey major coronary events and revascularization procedures, either angioplasty or coronary artery bypass surgery.
No patients with unstable angina exhibited cTn-I in their blood samples; accordingly, cTn-I was not found in the first blood sample of a patient who underwent myocardial infarction during hospitalization. During the follow-up 2 patients died of myocardial infarction, 9 patients had surgical revascularization and 5 patients angioplasty.
CTn-I is a sensitive and specific marker of myocardial necrosis. It is not found in patients with unstable angina; therefore it has no role as a prognostic marker of major coronary events.
不稳定型心绞痛意味着心肌梗死和猝死的高风险。在不稳定型心绞痛中，细胞质酶和蛋白质（肌酸磷酸激酶、肌酸磷酸激酶同工酶MB、肌钙蛋白T等）水平升高，这为即将发生的重大冠状动脉事件提供了信息。心肌肌钙蛋白I（cTn-I）是一种抑制肌动球蛋白ATP酶的结构蛋白；它仅存在于心肌细胞中。血清cTn-I滴定法最近已被引入临床实践，作为心肌细胞坏死的敏感和特异性标志物。
我们前瞻性研究的目的是评估不稳定型心绞痛且无心肌坏死迹象患者的血液样本中cTn-I的存在情况。此外，我们打算测试cTn-I在不稳定型心绞痛中作为短期和中期重大冠状动脉事件预后标志物的可能用途。
我们研究了33例因不稳定型心绞痛入住我们冠心病监护病房（CCU）的连续患者。根据不稳定型心绞痛的Braunwald分类，6例患者属于第一类，4例患者属于第二类，23例患者属于第三类。我们排除了急性或近期心肌梗死患者。所有患者的血液样本在入住CCU时采集，并在第一天和第二天每8小时采集一次。血清cTn-I滴定采用诊断巴斯德公司最近推出的夹心免疫酶法进行。进行了两个月的随访，以调查重大冠状动脉事件和血运重建手术，即血管成形术或冠状动脉搭桥手术。
不稳定型心绞痛患者的血液样本中均未检测到cTn-I；因此，在住院期间发生心肌梗死的患者的第一份血液样本中也未发现cTn-I。随访期间，2例患者死于心肌梗死，9例患者接受了外科血运重建，5例患者接受了血管成形术。
cTn-I是心肌坏死的敏感和特异性标志物。在不稳定型心绞痛患者中未发现它；因此，它在重大冠状动脉事件的预后标志物方面没有作用。
