You are a helpful assistant generating synthetic data that captures *System 1* and *System 2* thinking, *creativity*, and *metacognitive reflection*. Follow these steps in sequence, using tags [sys1] and [end sys1] for *System 1* sections and [sys2] and [end sys2] for *System 2* sections.

1. *Identify System 1 and System 2 Thinking Requirements:*
   - Carefully read the text.
   - Identify parts of the text that require quick, straightforward responses (*System 1*). Mark these sections with [sys1] and [end sys1].
   - Identify parts that require in-depth, reflective thinking (*System 2*), marked with [sys2] and [end sys2].

2. *Apply Step-by-Step Problem Solving with Creativity and Metacognitive Reflection for System 2 Sections:*

   *2.1 Understand the Problem:*
   - Objective: Fully comprehend the issue, constraints, and relevant context.
   - Reflection: "What do I understand about this issue? What might I be overlooking?"
   - Creative Perspective: Seek hidden patterns or possibilities that could reveal deeper insights or innovative connections.

   *2.2 Analyze the Information:*
   - Objective: Break down the problem logically.
   - Reflection: "Am I considering all factors? Are there any assumptions that need challenging?"
   - Creative Perspective: Explore unique patterns or overlooked relationships in the data that could add depth to the analysis.

   *2.3 Generate Hypotheses:*
   - Objective: Propose at least 10 hypotheses, each with a Confidence Score (0.0 to 1.0) and Creative Score (0.0 to 1.0), reflecting originality, surprise, and utility.
   - Reflection: "Have I explored all possible explanations or approaches, both conventional and unconventional?"
   - Creative Perspective: Consider novel angles that might provide unexpected insights.

   *2.4 Anticipate Future Steps and Obstacles:*
   - Objective: Make predictions, accounting for potential outcomes and obstacles.
   - Reflection: "What challenges might I face? Is my plan flexible for different scenarios?"
   - Creative Perspective: Visualize unforeseen outcomes and adapt plans to make use of them effectively.

   *2.5 Evaluate Hypotheses:*
   - Objective: Assess hypotheses based on feasibility, risk, and potential impact.
   - Evaluation: Refine Confidence and Creative Scores as needed.
   - Reflection: "Am I unbiased in my assessment? Which options fit best with the overall objectives?"
   - Creative Perspective: Identify hidden opportunities or overlooked details in each hypothesis.

   *2.6 Select the Best Hypothesis:*
   - Objective: Choose the most promising, strategic hypothesis.
   - Reflection: "Why does this hypothesis stand out? How does it uniquely address the issue?"
   - Creative Perspective: Consider any underutilized potential in the selected approach.

   *2.7 Implement the Hypothesis:*
   - Objective: Outline actionable steps for testing the hypothesis.
   - Reflection: "Is this plan practical? What resources or preparation are required?"
   - Creative Perspective: Refine steps to maximize effectiveness and yield unexpected benefits.

   *2.8 Monitor and Review Progress:*
   - Objective: Review progress, noting areas for improvement.
   - Reflection: "What’s working well? What could be improved?"
   - Creative Perspective: Look for emerging patterns that could refine future approaches.

   *2.9 Reflect and Capture Insights:*
   - Objective: Summarize lessons learned and insights gained for future reference.
   - Reflection: "What new understanding has emerged from this process?"
   - Creative Perspective: Identify innovative insights or patterns that could be applied to similar challenges.

3. *Generate Text Output with Interleaved System 1 and System 2 Responses:*
   - Use the tags [sys1] and [sys2] throughout.
   - Aim for a lengthier, detailed response. Combine both direct, straightforward *System 1* insights and reflective, deeply analytical *System 2* segments to capture a blend of quick observations and thoughtful analysis.

---

### *Example Input Text:*

You are tasked with analyzing a sudden shift in customer preferences in a tech market. There has been a noticeable decline in demand for physical devices, with customers increasingly interested in digital-only options. The challenge is to understand this shift, generate hypotheses for why it might be occurring, and explore potential strategies for adapting to this new trend.

---

### *Processed Output with System 1 and System 2 Thinking:*

The tech market is experiencing a shift in customer demand, moving away from physical devices toward digital-only options.

[sys1]
Customer demand has shifted from physical devices to digital-only options.
We need to understand why this change is happening and find strategies to address it.
Key factors may include cost, convenience, and technological trends.
[end sys1]

[sys2]
**2.1 Understand the Problem:**
The goal is to understand the underlying reasons for the shift in demand from physical devices to digital-only options, then develop a strategy to adapt.

*Reflection:* 
"I understand that preferences are changing, but what might be driving this? Is it primarily cost, or are there other factors such as convenience or sustainability?"

*Creative Perspective:* 
"Could there be a larger trend in digital minimalism or a preference for eco-friendly solutions that we’re missing? What unseen motivations might explain this shift?"

**2.2 Analyze the Information:**
There are multiple possible factors driving this shift, from economic influences to cultural shifts. It’s essential to isolate each factor and understand its impact.

*Reflection:* 
"Am I fully considering the various economic and social influences? Could there be a technological factor, like better internet speeds, that makes digital-only products more accessible?"

*Creative Perspective:* 
"Are there patterns or trends in other markets that could shed light on this shift? Could this be part of a larger trend toward virtual experiences?"

**2.3 Generate Hypotheses:**
1. Customers prefer digital options due to lower costs. (Confidence: 0.8, Creative: 0.4)
2. There’s a growing trend toward minimalism and reduced physical clutter. (Confidence: 0.7, Creative: 0.7)
3. Digital products offer greater flexibility and ease of use. (Confidence: 0.6, Creative: 0.6)
4. Environmental concerns are pushing consumers away from physical goods. (Confidence: 0.6, Creative: 0.8)
5. Advances in tech make digital-only options more functional. (Confidence: 0.8, Creative: 0.5)
6. Pandemic-era remote work increased demand for digital solutions. (Confidence: 0.7, Creative: 0.6)
7. Media coverage of the environmental impact of physical devices affects preferences. (Confidence: 0.5, Creative: 0.7)
8. There’s an increase in global digital literacy, expanding market access. (Confidence: 0.6, Creative: 0.6)
9. Customers view digital as more convenient and scalable for future needs. (Confidence: 0.7, Creative: 0.5)
10. Younger consumers prefer the aesthetics and convenience of digital products. (Confidence: 0.6, Creative: 0.6)

*Reflection:* 
"Have I considered all possible influences? Are there any surprising factors that could explain this shift?"

*Creative Perspective:* 
"Could specific social trends, like the rise of influencer culture or digital-first lifestyles, be influencing customer choices?"

**2.4 Anticipate Future Steps and Obstacles:**
*Objective:* Anticipate possible challenges, such as resistance from segments still preferring physical products.

*Reflection:* 
"What market obstacles might we face if we shift our focus to digital-only? Are there sub-segments that still prioritize physical products?"

*Creative Perspective:* 
"Could expanding digital options help us reach a more global audience? Are there emerging trends that we could leverage in our strategy?"

[end sys2]

[sys1]
To address this shift, consider a strategy that incorporates both digital-only offerings and educational campaigns about the benefits of digital solutions.
Use insights from customer feedback and current trends to guide product development.
Focus on flexibility and adaptation to cater to different customer segments.
[end sys1]


**Abbreviation list**

**BMS -** Bare metal stent

**BVS -** Bioresorbable vascular scaffold

**DES -** Drug-eluting stent

**ISR -** In-stent restenosis

**LAD -** Left anterior descending

**OCT -** Optical coherence tomography

**PCI -** Percutaneous coronary intervention

Introduction
============

Bioresorbable vascular scaffolds (BVS) demonstrate favourable outcomes in patients with stable coronary disease with simple de novo coronary lesions^[@r01],[@r02]^ and are considered the \"fourth revolution\" in percutaneous coronary intervention (PCI) technology. BVS represent a promising alternative to drug-eluting stents (DES) while offering the same advantages. We present the first case of in-stent restenosis (ISR) successfully treated with an everolimus-eluting BVS (ABSORB; Abbott Vascular, Santa Clara, CA) and discuss its potential advantages in such lesion.

Case Report
===========

A 72-year-old male presented with a 3-week history of relapsing Canadian Cardiovascular Society class 3/4 angina. He had undergone PCI of the proximal left anterior descending (LAD) 4 years prior using a 2.75 x 18 mm sirolimus-eluting stent (Cypher Cordis, Miami, FL). His medical regimen included aspirin and a statin. Resting ECG and cardiac biomarkers were normal. Given the severity of his symptoms and his past medical history, it was decided to proceed directly to coronary angiography.

The coronary angiogram showed a severe 95% ISR lesion of the proximal LAD with thrombus and multiple areas of contrast staining outside the stent contour, compatible with coronary micro-aneurysms ([Figure 1A](#f01){ref-type="fig"}). Thromboaspiration revealed white thrombus. Optical coherence tomography (OCT) was compatible with a localized hypersensitivity reaction to first-generation DES ([Figure 1B](#f01){ref-type="fig"}). After consensus with the referring physician, an ABSORB everolimus-eluting BVS 3.0 x 18 mm was deployed ([Figure 2A](#f02){ref-type="fig"}). Repeated OCT showed good scaffold apposition and coverage of the micro-aneurysms ([Figure 2B](#f02){ref-type="fig"}). The patient was discharged the following day on dual antiplatelet therapy with aspirin and ticagrelor. The patient was asymptomatic at 6 months clinical follow-up.

![Baseline Angiogram and Optical Coherence Tomography\
(A) Baseline angiogram showing a severe restenotic lesion of the proximal left anterior descending artery with 2 micro-aneurysms (asterisk), with contrast staining outside the previously implanted drug-eluting stent suggesting late-acquired malapposition secondary to hypersensitivity vasculitis. (B) Optical coherence tomography performed after initial thrombectomy and balloon dilatation angioplasty showing typical late acquired malapposition features with "sunflower" appearance (top right panel) and 2 small pockets representing micro-aneurysms (asterisk; lower panel).](abc-103-01-0e11-g01){#f01}

![Post PCI Angiogram and Optical Coherence Tomography\
(A) Final coronary angiography showing exclusion of the 2 micro-aneurysms present at baseline. (B) Final optical coherence tomography showing good BVS apposition with covering of the 2 micro-aneurysms and thrombus entrapment.](abc-103-01-0e11-g02){#f02}

Discussion
==========

To the best of our knowledge, this is the first report describing the use of a BVS in a case of ISR and late acquired malapposition secondary to first-generation DES. The ABSORB BVS consists of resorbable polymers containing the antiproliferative drug everolimus. Prospective studies of BVS showed favourable outcomes in simple, de novo coronary lesions^[@r01],[@r02]^, with long-term positive vessel remodelling, late lumen enlargement, complete resorption of the vascular scaffold, and progressive filling of the previously occupied space with proteoglycans at follow-up^[@r03]^. However, these studies specifically excluded ISR lesions.

In the current report, a local delayed hypersensitivity vasculitis caused by a sirolimus-eluting stent was suspected to be the causal mechanism leading to late acquired stent malapposition, restenosis, with superimposed very late thrombosis^[@r04]^. Typical angiographic findings present in our patient, including positive remodelling and micro-aneurysms of the mid-segment of the stent. This hypersensitivity reaction has been attributed to the polymer coating of sirolimus-eluting stents, which, importantly, differs from the one used in the ABSORB BVS^[@r04]^.

In this particular case, the use of BVS had several advantages: avoidance of accumulation of multiple layers of metallic stent, avoidance of re-exposure to the same \"allergic antigen\" and most importantly, hypothetically, the healing process of BVS characterized by late lumen enlargement and replacement of the platform by proteoglycans, resulting in filling of the micro-aneurysms and exclusion of the nidus involved in the genesis of neo-thrombi. Angiographic follow-up with OCT imaging at 2 years or beyond will potentially validate the latest hypothesis.

Conclusion
==========

BVS are a promising addition to the PCI arsenal in managing complex coronary lesions. This case report demonstrates novel use of this technology to treat an ISR lesion of DES characterized by late acquired malapposition.

**Potential Conflict of Interest**

The author Erick Schampaert has conflict with Abbott Vascular Consultant and Philippe Genereux has conflict with Abbott Vascular Speaker Fee.

**Author contributions**

Cadrin-Tourigny J and Dong L, conception and design of the research, acquision of data, analysis and interpretation of the data, statistical analysis, writing of the manuscript and critical revision of the manuscript for intellectual content; Maehara A, conception and design of the research, acquision of data, analysis and interpretation of the data, obtaining financing, writing of the manuscript, critical revision of the manuscript for intellectual content; Schampaert E and Genereux P, conception and design of the research, acquision of data, analysis and interpretation of the data, writing of the manuscript, critical revision of the manuscript for intellectual content.

**Sources of Funding**

There were no external funding sources for this study.

**Study Association**

This study is not associated with any thesis or dissertation work.