Intravascular ultrasound and outcomes after drug-eluting stent implantation

There have been nine published randomized trials and 30 registry studies comparing intravascular ultrasound (IVUS)-guided drug-eluting stent implantation versus conventional angiographic guidance. These trials and registries have been evaluated and summarized in (i) eight meta-analyses that included from nine to 18 registries and from one to seven randomized trials and (ii) four meta-analyses that included from three to eight randomized trials. Although with one exception no two meta-analyses have included the same trials or studies, in each meta-analysis, IVUS guidance was associated with a reduction in major adverse cardiac events as well as secondary hard endpoints of death (primarily cardiovascular mortality), myocardial infarction, and stent thrombosis, especially in randomized trial meta-analyses. This was explained in three meta-analyses comparing the acute results of IVUS versus angiographic guidance showing that (i) postdilation was used more frequently, and stent sizes, final angiographic minimum lumen diameters, and IVUS minimum stent areas were larger with IVUS guidance to minimize stent underexpansion and (ii) more stents were implanted and stents were longer with IVUS guidance to minimize geographic miss and treat edge dissections. IVUS-guided stent implantation can be used to minimize contrast during stent implantation, a strategy that is especially useful in patients with underlying renal insufficiency. Finally, an economic analysis showed that IVUS guidance was a dominant and cost-effective strategy, especially in patients with comorbid conditions who were at a higher risk of cardiac events and especially when the benefits of IVUS continued beyond 1 year.