Background: Direct stent implantation in patients, who undergo elective percutaneous coronary intervention (PCI) can be performed with a high success rate and clinical results that are comparable to those after predilatation. It was the aim of this prospective study to compare clinical, angiographic and procedural parameter of direct stent implantation (DS) and conventional stent implantation (CS) in patients with acute coronary syndrome (ACS).
Patients and methods: We analysed 194 patients with ACS (ST-elevation myocardial infarction 66%, non-ST-elevation myocardial infarction 18%, unstable angina 16%), in whom primary PCI was performed between January and December 2002. In 156 (80%) patients glycoprotein IIb/IIIa inhibitors were administered during the procedure. In 73 patients (38%) direct stent implantation could be performed successfully. In 12 patients (6%) direct stent implantation failed due to the inability to pass the stenosis. In 121 patients (62%) the stent was implanted after predilatation.
Results: The clinical parameters were comparable in both groups. Reference luminal diameter before stent implantation did not differ in both groups (DS 3.01+/-0.54 vs. CS 2.84+/-0.43 mm). The final minimal luminal diameter was significantly higher in the DS group (DS 2.95+/-0.45 vs. CS 2.77+/-0.47 mm, p=0.01). The procedural time (DS 41.0+/-14.1 vs. CS 46.8+/-16.9 min, p=0.02), radiation exposure time (DS 7.3+/-4.6 vs. CS 8.9+/-4.6 min, p=0.002) and the amount of contrast agent (DS 216+/-90 vs. CS 235+/-79 ml, p=0.03) could be decreased by the technique of direct stent implantation. The incidence of major adverse cardiac events (death, myocardial infarction, CABG) during hospitalization was 4.1% in the DS group and 11.5% in the CS group (p=0.11).
Conclusions: Direct stent implantation is safe and feasible in patients with acute coronary syndromes. The procedural time, radiation exposure time and the amount of contrast agent can be significantly decreased using the technique of direct stent implantation. The incidence of major adverse cardiac events was not significantly different in this subset of patients.