Vergleich von Nominal- versus Hochdruckballoninflatation für optimale Koronarstent-Implantation durch IVUS und QCA mit EXPRESS Coronary Stent System

Despite being recommended by the American College of Cardiology
Expert Consensus Document on Coronary Artery Stents, high pressure
post-dilatation strategy still encountered several controversies
due to its deleterious effects on the vascular wall and its
distortion of the stent geometry leading to a predilection to
restenosis. Researches were geared to the development of newly
designed coronary stent systems to be deployed at low pressure
minimizing vessel trauma. In this study, the EXPRESS Coronary Stent
System underwent scrutiny based on QCA and IVUS comparing both
nominal and high balloon inflation pressures. IVUS and selective
coronary angiography were performed after initial stent deployment
at 9 atmospheres and after post-stent dilatation up to as high as
20 atmospheres. If stent deployment was not perceived to be
optimal, stent was dilated once to three times and post-stent
balloon inflation pressure could be increased at the discretion of
the investigator until perceived to be optimally expanded according
to the Modified “MUSIC” criteria. Stents implanted at nominal
pressure and perceived to be already successfully deployed
sonographically and angiographically belonged to Group A (n=17). No
high-pressure post-stent dilatation was required. Stents implanted
at nominal pressure and perceived to be not optimal by angiography
with or without IVUS were further dilated with higher balloon
pressure inflations until perceived to be successfully deployed
based on angiography and IVUS. These belonged to Group B (n=23).
Pre-dilatation was performed on both groups once to three times
when perceived to be necessary. The routine protocol for
anti-thrombotics and anti-coagulants was also followed. The
immediate outcome of PCI from both groups were comparable. However,
the high pressure group had poorer AHA/ACC lesion type and heavier
lesion calcification. This could had prevented achieving a much
higher yield of successful stent deployment. The inaccurate QCA
interpretation at low pressures could have explained the apparent
disagreement between the two imaging modalities.