[Absence of benefit with triple antiaggregation in acute non persistent ST segment elevation myocardial infarction in patients not subjected to early interventionism]

Abstract

Objective: To assess the efficacy and safety of a treatment with clopidogrel when associated or not to the treatment with tirofiban and aspirin for high-risk non-ST segment elevation myocardial infarction (non-STEMI), without early angioplasty.

Setting: Intensive Care and Coronary Unit (ICCU), in a center with no Hemodynamic Laboratory.

Design: Non randomized clinical trial.

Participants: One hundred and twenty-three patients admitted with the diagnosis of high-risk non-STEMI, defined as patients with chest pain and one of the following: ST segment depression or transient elevation or an elevation in cardiac troponin I (TropIc).

Interventions: We included patients admitted in a 24-month period. During the first 12-month period, the patients received tirofiban and clopidogrel (group A). In the second one, clopidogrel was not administered (group B). Urgent cardiac catheterism was requested if recurrent ischemic chest pain with ST segment changes, left ventricular failure or hemodynamic instability were present. PRIMARY VARIABLES: A composite of recurrent ischemic chest pain with ST segment changes or death during ICCU admission was evaluated as an efficacy variable. A variable of safety was defined as the occurrence of intracranial or gastrointestinal bleeding, or any hemorrhagic event accompanied by a drop of at least 3 g/dl of hemoglobin. The rate of urgent cardiac catheterisms was recorded.

Results: Neither the rate of the efficacy variable (19.6 % in group A and 19.4% in group B; p = 0.97), nor the rate of the safety variable (3.5% and 2.9% of patients in groups A and B, p = 1) showed statistically significant difference. There was no statistically significant difference in the rate of urgent cardiac catheterism (19.6% in group A and 13.4% in group B; p = 0.35).

Conclusions: In the early course of high-risk non-STEMI with a conservative management strategy, the addition of clopidogrel to tirofiban does not change the rate of ischemic events, death, need of urgent catheterism or hemorrhagic events.