Putting the microscope on stent thrombosis
- Cardiovascular Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust, London, UK
- Correspondence to Professor Carlo Di Mario, Department of Cardiology, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK;
Contributors Professor Di Mario and Dr Lindsay co-authored the paper. Each was responsible for writing and reviewing the text.
- intracoronary doppler
- intravascular ultrasound
- acute myocardial infarction
- interventional cardiology
Intravascular ultrasound (IVUS) initially gained widespread use in interventional cardiology as a technique to prevent stent thrombosis (ST) by detecting and avoiding angiographically unapparent underexpansion, malapposition and incomplete lesion coverage. In a seminal report from the Milan group, a large series of patients receiving stents for complex lesions showed a very low incidence of thrombosis using aspirin alone1—in contrast with the more aggressive anticoagulation regimes that had been used up to that point—when IVUS guidance was used. The results were subsequently duplicated in a small multicentre study (MUSIC) which used stringent criteria of stent deployment and expansion.2 However, these results were subsequently muddled by the discovery of the additional protective effect of thienopyridines (ticlopidine, and later clopidogrel3–5), which emphasised that ST is a complex multifactorial phenomenon where technical errors in deployment can be somewhat rescued by a more intense antiplatelet regimen.
In the subsequent dual antiplatelet era, and particularly following the near-elimination of a dangerous confounder, such as occlusive restenosis by the introduction of drug eluting stents (DES), the evidence in favour of a protective effect of IVUS guidance was only indirect, coming from large registries showing higher percentages of underexpansion and/or malapposition in patients with ST,6 ,7 or by studies like the current one in Heart from Alfonso et al,8 examining the IVUS findings in consecutive series during acute retreatment. Later, results presented by Cook et al,9 and by Alfonso et al in a previous study,10 confirmed that underexpansion and malapposition, also observed in smaller observational series, remained associated with late stent failure …