Overview
This is a prospective, single-center, single-arm exploratory observational study aiming to evaluate the impact of stepwise pressure-increasing non-compliant (NC) balloon post-dilation on stent expansion rate in patients undergoing single-stent implantation for coronary artery stenosis, with stent sizing guided by intravascular ultrasound-external elastic membrane (IVUS-EEM) measurement.
A total of 150 eligible patients will be enrolled at The First Hospital of Jilin University. All participants will receive standard single-stent implantation followed by multi-stage stepwise pressure-increasing NC balloon post-dilation under IVUS monitoring. The post-dilation protocol includes sequential inflation at nominal pressure, rated burst pressure, and 24 atm, with IVUS assessment performed after each stage. All treatment procedures are conducted in accordance with routine clinical practice; no additional randomization or mandatory intervention is applied beyond the standard of care. The study solely observes and records outcomes associated with this treatment strategy.
Description
Coronary atherosclerotic heart disease remains one of the leading causes of mortality and disability worldwide. Coronary stent implantation is a principal therapeutic strategy for coronary artery stenosis. The adequacy of stent expansion is a critical determinant of treatment efficacy; inadequate stent expansion may lead to stent malapposition, in-stent restenosis, stent thrombosis, and other adverse events that significantly compromise patient prognosis.
Intravascular ultrasound (IVUS), as an invasive vascular imaging modality, enables clear visualization of vessel wall architecture, plaque characteristics, and immediate post-stent implantation outcomes. Among its measurements, the external elastic membrane (EEM) cross-sectional area serves as a key reference for stent sizing, effectively overcoming the inherent limitation of conventional coronary angiography, which relies solely on luminal imaging for stent diameter selection.
Non-compliant (NC) balloon post-dilation is an essential step in optimizing stent implantation outcomes. Gradual incremental increases in balloon pressure may further promote adequate stent expansion and improve stent-vessel wall apposition. However, the specific impact of NC balloon post-dilation at different pressures and durations on stent expansion rate has not been systematically validated. To date, there remains a paucity of dedicated studies investigating the dynamic changes in stent expansion rate under a stepwise pressure-increasing protocol.
This study utilizes IVUS-EEM measurements to guide stent sizing and adopts a single-stent implantation strategy combined with multi-stage stepwise pressure-increasing NC balloon post-dilation. after stent deployment with norminal pressure, 12\10 atm, 18\10 atm and 24\*10 atm NC balloon post-dilation. IVUS measurement will be made after each step and stent expansion and Minimal stent area will be documented.
Primary Endpoint. Minimum Stent Area (MSA)
IVUS-measured minimum lumen cross-sectional area within the stented segment post-procedure (after stent deployment with norminal pressure, 12\10 atm, 18\10 atm and 24\*10 atm NC balloon post-dilation)
Secondary endpoints:
Stent Expansion Rate
IVUS-measured stent expansion rate immediately post-procedure (after stent deployment with norminal pressure, 12\10 atm, 18\10 atm and 24\*10 atm NC balloon post-dilation), calculated as: (minimum stent cross-sectional area \[MSA\] measured by IVUS / manufacturer's nominal MSA) × 100%.
rates of stent edge dissection, hematoma, perforation.
Eligibility
Inclusion Criteria:
- Age ≥18 years regardless of gender;
- Coronary angiography confirms single-vessel coronary artery stenosis ≥50%, meeting the indication for single-stent implantation;
- Preoperative IVUS examination can clearly visualize the vessel EEM, allowing for stent size measurement and assessment of stent expansion-related parameters;
- The patient voluntarily participates in this study and signs the informed consent form;
- No contraindications related to IVUS examination, stent implantation, or balloon angioplasty.
Exclusion Criteria:
- Hemodynamically unstable
- Presence of anatomical or pathological factors preventing IVUS catheter crossing.
