Expansion of Intracoronary Stents by Low Pressure Oversizing Versus High Pressure Inflation: A Randomised Intracoronary Ultrasound Controlled Study
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Coronary Angioplasty and Stenting
- Sponsor
- Sydney South West Area Health Service
- Enrollment
- 40
- Locations
- 1
- Primary Endpoint
- Number of stents which are optimally deployed as assessed against the MUSIC criteria
- Last Updated
- 9 years ago
Overview
Brief Summary
Stent placement is now widely accepted to improve the results of angioplasty (an operation to widen the blood vessel) and decreasing the need for further surgery. Despite their worldwide acceptance, stent usage is still limited by renarrowing which occurs within the stent (restenosis) in some patients within the first six months. In addition there still exists a small risk of heart attacks soon after the stent is placed.
The purpose of this study is to test the safety and tolerability of trying to place the stents using a different strategy of using low pressure oversized balloon inflations as opposed to the usual high pressure balloon inflations. This may reduce injury to the artery and reduce the chance of renarrowing of the stent. In order to ensure this is a safe and effective way of performing the procedure the investigators intend to use an Intravascular ultrasound (IVUS) catheter to look from inside the artery at the stents. IVUS has proven to be the best way of ensuring optimal stent placement.
Primary hypothesis: Stents will be equally well expanded and apposed using a strategy of oversized stenting at normal inflation pressures ( < 10 atmospheres ) as compared to high pressure inflation (≥14 atmospheres) as guided by intravascular ultrasound imaging.
Secondary Hypothesis: There will be no difference in acute clinical endpoints (death, myocardial infarction, urgent revascularisation or stent thrombosis) using a strategy of oversized stenting at normal inflation pressure as compared to high pressure inflation.
Tertiary Hypothesis: If the above is shown to be true the investigators would hope to expand the study in order to reveal a decrease in stent restenosis using a strategy of lower pressure balloon inflations. The investigators will assess the deployment characteristics of drug eluting versus bare metal stents
Investigators
Esther Zhou
Research Medical Student
Sydney South West Area Health Service
Eligibility Criteria
Inclusion Criteria
- •Patients who are scheduled for a coronary angioplasty and stenting
- •Single de novo artery stenosis are eligible for this study
- •Target lesion needs to be less than 30mm long and located in a vessel more than 2.5 mm in diameter
Exclusion Criteria
- •Contraindication to antiplatelet therapy;
- •Ostial lesion;
- •Excessive vessel tortuosity;
- •Lesion at a significant bifurcation (subbranch ≥ 2mm in diameter);
- •Suspected intracoronary thrombus.
Outcomes
Primary Outcomes
Number of stents which are optimally deployed as assessed against the MUSIC criteria
Time Frame: Immediately after stent is deployed until optimal deployment is achieved
The criteria for optimal stent expansion are: 1. Complete apposition of the stent over its entire length against the vessel wall. 2a. In stent minimal luminal area (MLA) \>= 90% of the average reference luminal area or \>=100% of lumen area of the reference segment with the lowest lumen area. In stent lumen area of proximal stent entrance \>= 90% of proximal lumen area. 2b. Where the instent luminal area is in excess of 9.0 mm2 , the following criteria apply: In stent MLA \> 80% of the average reference lumen area or \>=90% of lumen area of the reference segment with the lowest lumen area. In stent lumen area of proximal stent entrance \>= 90% of proximal lumen area. 3. Symmetric stent expansion defined by lumen diameter (LD)min / LD max \>= 0.7 A less rigorous criteria for stent expansion will also be assessed: 1. In stent MLA \> 80% of the average reference lumen area; \& 2. Complete apposition of the stent over its entire length against the vessel wall
Secondary Outcomes
- Clinical endpoints including death, myocardial infarction, coronary artery bypass surgery, repeat percutaneous intervention, stent thrombosis, myonecrosis(1-3 days following procedure and at 6 months)