Does IVUS guidance of coronary interventions affect outcome? a prime example of the failure of randomized clinical trials

Abstract

There has been a decline in the role of intravascular ultrasound (IVUS) guiding stenting. IVUS has lost favor with interventional cardiologists largely due to the emergence of drug eluting stents (DES). The advent of DES has lowered the need to maximize the final result due to the known low late-loss. This phenomenon has contributed to reduced interest in optimizing results with IVUS guidance. However, current concerns regarding stent thrombosis in relation to DES and its associated significant morbidity and mortality has once more focused attention on optimal stent deployment. Prior to DES, the evidence base was rather ambiguous, as some randomized and observational studies supported IVUS guided bare metal stent insertion in terms of reducing rates of restenosis and clinically driven target lesion revascularisation whereas others demonstrated no such benefit. As there is an additional cost and learning curve with IVUS, it has become difficult to justify its routine use. We present here a contemporary argument for the resurgence of IVUS optimized stent insertion. We also highlight deficiencies in previously adopted IVUS optimization criteria, which were based on distal and proximal lumen sizes. The new criteria proposed are based on vessel size at different segments of the stented area and therefore take advantage of vessel remodeling. The availability of high pressure, non-compliant balloons have made attainment of these new optimization targets possible without increasing the risk of complications. We hope to demonstrate this statement with the completion of the angiographically versus IVUS optimization (AVIO) study that soon will be initiated.