The low pressure stent observational trial on the procedural and mid-term outcome of a trapezoid-shaped coronary stent (LOPSTER).

Background: Stent design influences the procedural and mid-term results of coronary interventions. The trapezoid-shaped struts of the low pressure stent (LP-Stent) might improve the outcome by reducing the vascular trauma at deployment.

Methods: A total of 133 patients (64.5+/-8.6 years) with significant de novo coronary lesions (reference diameter >or=2.8 mm, length <15 mm, and stenosis >or=70% and <100%) were enrolled for single stent deployment and a 6-month clinical and angiographic follow-up.

Results: Stents were successfully deployed to 131/133 (98.5%) lesions. In one failed procedure (0.8%), the stenosis could be crossed with another device whereas in the second alternative stents also failed. Following edge dissection after LP-Stent implantation, in 9/133 (6.8%) patients additional stents were deployed. Follow-up was performed as scheduled after 5.9+/- 0.9 months in 98/122 (80.3%) patients, prematurely for in-stent restenosis in 8/122 (6.6%), and clinically only in 8/122 (6.6%). Deaths, one of cardiac origin (0.9%), occurred in 2/114 (1.8%), and myocardial infarctions in 1/114 (0.9%). The culprit stenoses were dilated from 78.4+/-9.7% to 23.3+/-11.0% recurring to 43.1+/-24.3% at scheduled follow-up. The late loss of 0.6+/-0.8 mm and late loss index of 0.3+/-0.5 translated into a binary restenosis rate of 24/98 (24.5%) requiring reintervention in 19/98 (19.4%).

Conclusions: In summary, the LP-Stent is associated with reduced intimal proliferation as reflected by the low late loss index when being compared with either non-coated or passively coated devices and higher in comparison to active coated stents. The considerable dissection rate seems to be related to higher deployment pressures and warrants design modification at the stent's distal edges.