Background: Standard high-pressure stent implantation frequently results in suboptimal stent expansion by intravascular ultrasound (IVUS) criteria. We aim to show that routine expansion of the stent to a diameter greater than the reference segment, leading to an angiographic step-up at the proximal stent edge and step-down at the distal stent edge, results in improved stent expansion.
Methods: We studied 25 patients undergoing coronary stent implantation. Twelve patients were randomized to standard sizing and 13 patients to step-up and step-down sizing as the angiographic goal. IVUS was then performed on all patients to detect incomplete stent strut apposition, dissection within the stent or a suboptimal stent expansion index (SEI). SEI was defined as the minimum stent area (MSA)/average reference lumen area x 100. Optimal SEI was defined as greater than or equal to 90% for a MSA less than or equal to 9.0 mm2 and greater than or equal to 80% for a MSA >9.0 mm2.
Results: Four patients (33%) treated with standard stent implantation and 12 patients (92%) treated with the step-up and step-down approach (p = 0.004) achieved optimal stent expansion. No patients in either group had unapposed stent struts or instent dissection on IVUS. There were no major adverse cardiac events on 6-month follow up.
Conclusions: Stent deployment with an angiographic step-up and step-down approach improves the likelihood of optimal stent deployment by IVUS criteria as compared to the standard angiographic endpoint. This stenting technique is a simple and frugal alternative to IVUS-guided percutaneous coronary intervention, achieving very high rates of adequate stent apposition and expansion.