Analysis of the relation between stent implantation pressure and expansion

Intravascular ultrasound (IVUS) imaging has demonstrated that most coronary stents implanted at low pressure are underexpanded.(1,2) Routine high-pres sure dilatation typically results in greater stent dimensions,(1-4) which h as been associated with improved late clinical and angiographic outcomes.(3 -5) Numerous studies have now demonstrated that the predominant predictors of freedom from restenosis after stenting are the minimal luminal diameter (MLD) and area achieved.(6-9) Although high pressures are now routinely use d to increase stent expansion, the relation between stent implantation pres sure and luminal dimensions has not been rigorously studied, and the level of pressure used varies widely. Therefore, to examine the relation between implantation pressure, stent expansion, and the adequacy of stent deploymen t, a prospective, controlled study was performed in which stents were impla nted and serially dilated in each lesion at 12, 15, and 18 atm, and evaluat ed at each pressure level with quantitative coronary angiography and IVUS, with independent core lab assessment. A secondary goal of the study was to determine whether IVUS has utility in assessing stent expansion (beyond ang iography) if high pressures are routinely used.