Optimal Stent Deployment Strategy of Contemporary Stents

Study Overview
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Brief Summary
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The primary objective is to evaluate whether a standard pre- and postdilatation (PSP strategy) of the modern DES results in a more optimal stent implantation compared to DS as evaluated by OCT in patients with stable coronary artery disease. The secondary clinical objective is to evaluate clinical cardiovascular outcomes in patients with stable coronary artery disease treated with the PSP strategy.

Detailed Description
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Rationale: Historically, when coronary stents were initially introduced, the standard and mandatory treatment of a significant stenosis was with pre-dilation prior to stent placement. In the 2000s, several studies found no significant difference in clinical outcome between the two different stent implantation techniques: direct stenting (DS) versus the conventional stenting after pre-dilation (CS). Consequently, the stent implantation technique has become unprotocolarised, i.e. each operator has their own, individual set of reasons for applying or avoiding pre- and post-dilation in specific conditions. However, these trials do not apply to the current/modern clinical practice of coronary stenting. The current patient population undergoing percutaneous coronary intervention (PCI) cannot be compared to the population that was treated in the early 2000s. The same applies for stent design. Stents have undergone several major transformations in the last 20 years. Furthermore, the events rates after PCI have significantly decreased within the last decades due to better stent design and improved background pharmacological therapy. Imaging studies have revealed that an optimal stent result is not achieved in a high percentage of stent implantations. Post-hoc studies have demonstrated that the optimization of the implantation technique could reduce adverse cardiac events over time. As a result of these findings, the PSP concept: Pre-dilation, Sizing and Post-dilation was introduced. Whether routine pre- and postdilatation compared to DS also results in optimal stent implantation in contemporary drug-eluting stents (DES) has not been investigated and, hence is currently unknown. Objective: The primary objective is to evaluate whether a standard pre- and postdilatation (PSP strategy) of the modern DES results in a more optimal stent implantation compared to DS as evaluated by OCT in patients with stable coronary artery disease. The secondary clinical objective is to evaluate clinical cardiovascular outcomes in patients with stable coronary artery disease treated with the PSP strategy.

Official Title
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OPtimal stEnt Deployment stRategy oF Contemporary sTents

Conditions
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Coronary Artery Disease

Intervention / Treatment
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* Procedure: PCI


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Stable angina patients or acute coronary syndrome patients with bystander stable coronary artery disease With one or more significant epicardial stenosis in native coronary arteries suitable for direct stenting, according to the judgement of treating operator. The use of fractional flow reserve (FFR) or resting indices like iFR and RFR to assess lesion severity is encouraged. Subject must be at least 18 years of age Written consent to participate in the study Exclusion Criteria: Lesions not suitable for direct stenting, like (sub)-total stenosis, severely calcified lesions Culprit lesions of acute coronary syndrome cannot be randomized to the trial. After successful treatment of the ACS culprit lesion, patients however can be randomized in the trial in case of remaining stable non-culprit lesions that thought to be stented directly of during a staged procedure. Lesions not suitable for OCT catheter delivery and imaging, e.g. left main or ostial right coronary artery stenosis, lesions in coronary bypass grafts or tortuous anatomy Treatment for in-stent restenosis Bifurcation lesions in which a two-stent technique or a proximal postdilatation is planned. Treatment of coronary artery bypass grafts Creatine Clearance ≤ 30 ml/min/1.73 m2 (as calculated by MDRD formula for estimated GFR) Known hypersensitivity or allergy for cobalt chromium Known comorbidity associated with a life expectancy < 1 year Unable to understand and follow study-related instructions or unable to comply with study protocol

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 100 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: single-center, prospective, single blinded randomized clinical trial
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: PSP technique<br>The definitions of the PSP technique are: Predilatation is mandatory with a balloon diameter equal to or maximally 0.5 mm less than the distal reference vessel diameter. We hypothesize that this lesion preparation and fracture of the calcium may result in better stent apposition, less recoil and higher minimal stent area (MSA) Also see endpoints. The DES should be deployed at 2 atm. above the nominal pressure. This relatively low stent deployment pressure may prevent stent edge dissections. The postdilatation is mandatory with a shorter length and (at least 0.25mm) larger diameter non-compliant balloon at 16 atm. The apposition, minimal stent area (MSA) and recoil may improve with this large, high pressure postdilatation. The slightly shorter balloon can prevent edge dissections. | Procedure: PCI<br>* percutaneous coronary intervention<br>|
| Active Comparator: Direct Stenting<br>• The DES is directly placed without any lesion preparation and deployed at a pressure at the discretion of the operator. Ideally a pressure would be achieved in which angiographic expansion of the DES is complete (without significant dog-boning) | Procedure: PCI<br>* percutaneous coronary intervention<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Suboptimal stent results which is defined as a composite of major stent underexpansion and major edge dissection measured by OCT at lesion level directly after completion of the stent implantation according to the protocol | Stent malapposition (categorical variable) is defined as: Unacceptable stent expansion: The minimal stent area (MSA) of the proximal segment is <90% of the proximal lumen area, and/or the MSA of the distal segment is <90% of the distal reference lumen area on OCT OR Presence of incompletely apposed stent struts on OCT more than 3mm long (defined as stent struts clearly separated from the vessel wall (lumen border/plaque border) without any tissue behind the struts with a distance from the adjacent intima of ≥0.2 mm and not associated with any side branch: i.e. the Prati criterium) Edge dissections (categorical variable) will be presented as: • Dissections on OCT of ≥60 degrees of the circumference of the vessel at the site of dissection and ≥3 mm in length | through procedure completion, the day of the index procedure (day 0) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Minimal stent area (MSA) (mm2) |  | through procedure completion, the day of the index procedure (day 0) | 
| Acute recoil (%) | assessed on coronary angiography | through procedure completion, the day of the index procedure (day 0) | 
| Stent malapposition (%) | defined as frequency of incompletely apposed stent struts (defined as stent struts clearly separated from the vessel wall (lumen border/plaque surface) without any tissue behind the struts with a distance from the adjacent intima of ≥0.2 mm and not associated with any side branch). | through procedure completion, the day of the index procedure (day 0) | 
| Mean stent expansion (%): | mean stent area (stent volume/analysed stent length) divided by the average of proximal and distal reference lumen areas x 100 | through procedure completion, the day of the index procedure (day 0) | 
| Intra-stent plaque protrusion and thrombus | defined as any intraluminal mass protruding at least 0.2 mm within the luminal edge of a stent strut | through procedure completion, the day of the index procedure (day 0) | 
| Post OCT stent result optimalization (%) | composite of additional post-dilation and/or stent placements after OCT | through procedure completion, the day of the index procedure (day 0) | 
| MACE | a composite of time- to-first event rate of cardiac death, target vessel MI, ischemia-driven target vessel revascularization (TVR) | 1-,3- and 5-year follow-up | 
| Target Lesion Failure (TLF) | defined as cardiac death, target vessel- myocardial infarction and clinically indicated target lesion revascularization) | 1-,3- and 5-year follow-up | 
| Target Vessel Failure (TVF) | defined as cardiac death, target vessel- myocardial infarction and clinically indicated target vessel revascularization | 1-,3- and 5-year follow-up | 
| All cause mortality |  | 1-,3- and 5-year follow-up | 
| Stent Thrombosis | definite or probable; ARC definition | 1-,3- and 5-year follow-up | 
| Cost-effectiveness analysis | total number of stent, balloons, wires and repeat hospitalizations due to MACE | 1-,3- and 5-year follow-up |