Direct stent implantation in acute myocardial infarction.: The DISCO 3 study

Introduction and objectives. An association has been reported between direct stenting in primary angioplasty and low incidences of the no-reflow phenomenon and distal embolization. The aims of this study were to determine the proportion of patients who can be treated by direct stent implantation and to identify factors that establish when the technique should be used in acute myocardial infarction in clinical practice. Patients and method. This prospective descriptive and multicenter study (DISCO 3) included 189 patients. Angiographic reperfusion parameters were recorded and resolution of the ST-segment elevation was monitored. Adverse clinical events, such as death, non-fatal reinfarction and repeat revascularization of the culprit vessel, were recorded at discharge, and after one and six months. Results. Direct stenting was performed in 56% of patients, and stenting after predilatation in 44%. The main predictors of direct stenting were short postinfarction delay, non-zero initial TIMI flow, and preinfarction angina. The most common reasons for balloon predilatation were TIMI flow zero on traversing the lesion with a guidewire (92%), involvement of a major bifurcation or tortuous vessel, and severe calcification. Indices of myocardial reperfusion were better with direct stenting: TIMI myocardial perfusion grade 2-3 flow was present in 84% vs 69% (P=.005), and > 70% ST-segment resolution occurred in 66% vs 42% (P=.003). No difference in adverse clinical events was found. Conclusions. Direct stenting is feasible for treating acute myocardial infarction in more than half of patients. The lesions should not be severely calcified nor involve tortuous vessels, and there should be sufficient flow following passage of a guidewire to define the lesion's characteristics.