PALS: A Guide to DCB in PCI

Introduction to PALS and Interventional Cardiology

  • Overview of the session and speaker's background.

  • Session is designed to be interactive with Q&A. The speaker encourages participants to ask questions throughout the session to enhance engagement and understanding.

  • Speaker is a consultant cardiologist in Bournemouth, UK.

    • Specializes in treating elderly patients with calcified coronary disease, as well as managing non-STEMI and STEMI patients.

    • The speaker's interventional cardiology practice has evolved, with historical volumes of approximately 2,0002,000 PCIs per year, which have been adjusted to around 1,5001,500 post-COVID due to changes in practice and patient management.

    • Appointed in 2007, initially performing approximately 600600 cases per year, and currently involved in about 350350 cases annually, reflecting a focus on more complex and carefully selected interventions.

  • Specialist interests:

    • Bifurcations (part of the European Bifurcation Club), focusing on advanced techniques for treating lesions at vessel branch points.

    • Intracoronary imaging (used in approximately 95% of cases) to guide interventions and optimize outcomes.

    • Calcium treatment (rotablation, orbital atherectomy, IVL, laser), employing various methods to modify calcified lesions for better stent deployment and vessel patency.

    • Extensive experience with various bifurcation stents and devices, including Abbott's Absorb bioresorbable scaffold, showcasing a commitment to innovative treatment options.

A Case Study: Treating a Young Patient with Unstable Angina

  • Presentation of a 32-year-old patient in December 2020 with unstable angina, highlighting the challenges in managing acute coronary syndromes in younger individuals.

    • Troponin rise of approximately 150150, indicating myocardial damage.

    • Anterior ECG changes, suggesting ischemia in the anterior heart region.

  • Angiogram findings:

    • Tight stenosis in the proximal LAD (left anterior descending artery), indicating a significant blockage in a critical vessel.

    • "Widow maker" lesion with a large area of myocardium at risk, emphasizing the severity and potential consequences of the blockage.

  • Initial treatment with balloon angioplasty using a paclitaxel-coated Angiosculpt X balloon to open the blocked vessel and restore blood flow.

    • Good initial result, as noted by improved vessel diameter and flow.

  • Colleague's skepticism about balloon-only treatment, reflecting concerns about long-term patency and potential for restenosis.

  • Patient presentation a few months later with chest pain, raising concerns about recurrent ischemia.

    • Angiogram appeared similar to the post-angioplasty result, complicating the decision-making process.

    • Colleague considered stent placement but deferred based on OCT findings, illustrating the value of intracoronary imaging in guiding treatment decisions.

  • OCT results:

    • No significant stenosis was detected, challenging the initial angiographic findings.

    • Adequate minimal luminal area, supporting the decision to avoid stenting.

  • Decision against stent placement was guided by OCT findings and obtaining a second opinion, emphasizing a conservative approach based on comprehensive assessment.

The Journey to Destination Therapy in PCI

  • Three ways to finish a prepared vessel: metallic stent, drug-coated balloon (DCB), or scaffold, providing a range of options for interventional cardiologists.

  • Evolution from Andreas Grunzig's initial balloon angioplasty without stenting or drugs, underscoring the significant advancements in the field.

  • Contemporary practice involves lesion assessment (IVUS, OCT, physiology), vessel preparation (scoring/non-compliant balloons, calcium devices), and finishing strategy (metallic stent or DCB), highlighting a comprehensive approach to PCI.

  • Transition from complex solutions for simple lesions to simple solutions for complex disease, reflecting a trend towards more tailored and effective treatments.

  • Case example: Culotte stenting for a benign lesion in 2014, showcasing a specific technique for bifurcation lesions.

  • Experience with access stents for bifurcations to keep the carina free of metal, representing efforts to optimize bifurcation stenting techniques.

    • Required extensive vessel preparation, emphasizing the importance of proper lesion preparation.

  • Shift towards bioabsorbable scaffolds (e.g., Absorb) in 2007, illustrating a move towards transient scaffolding.

    • Absorb used in a complex circumflex bifurcation with good results at 8-year follow-up, providing long-term evidence of scaffold efficacy.

  • Involvement in the Solution trial, comparing DCB and stent treatments, contributing to the evidence base for DCB use.

The PALS Concept: A Framework for DCB Use

  • Collaboration with colleagues (Paul Brady, John Hinton, Jahangar Din) to develop the PALS concept, highlighting a team-based approach to innovation.

  • PALS = Patients, Anatomy, Long-term, Simplification

  • Patients:

    • Younger patients (under 55) who may benefit from avoiding long-term stent implications.

    • Diabetics, where DCB can reduce the risk of restenosis compared to stents.

    • High bleeding risk patients in whom prolonged dual antiplatelet therapy (DAPT) is undesirable.

    • Poor compliance with medications, making shorter DAPT regimens with DCB an attractive option.

    • Renal failure patients who may have contraindications to certain stent types or prolonged DAPT.

  • Anatomy:

    • Restenosis cases, where DCB can be effective in treating in-stent restenosis.

    • Bifurcations, utilizing DCB to minimize metal layers at the bifurcation.

    • Tortuosity of vessels, where DCB can be deployed without the challenges of stent delivery.

    • Aorto-ostial disease, using DCB to avoid stent protrusion into the aorta.

    • Side branch ostium, where DCB can treat lesions without compromising the main vessel.

    • Calcium, using DCB after adequate vessel preparation with atherectomy.

    • Diffuse plaque, where DCB can treat long lesions without multiple overlapping stents.

    • Small vessels, where DCB can avoid the risks associated with small stent implantation.

  • Long-term:

    • Avoiding stent-related failures, such as stent thrombosis and restenosis.

    • Providing more future treatment options, as DCB leaves the vessel architecture intact.

  • Simplification:

    • Moving from heavy metal to minimal footprint strategies, reducing the long-term burden on the vessel.

Deep Dive into Small Vessels

  • Small vessels are a significant area for DCB application, as stents can lead to higher rates of restenosis and target lesion revascularization.

  • 2.5 mm stents: if left at 2.5 mm, area is just 4.9mm24.9 mm^2. MSA should be greater than 4.9mm24.9mm^2. According to Ziad's analysis of 4 aluminum stent failure, any MACE rate is higher below 5mm25mm^2.

  • In the UK, 25% of stents used are 2.5 mm, highlighting the prevalence of small vessel interventions.

  • Small vessel DCB results are equivalent to stenting (from the K3 trial), providing evidence for the efficacy of DCB in this challenging anatomy.

  • Potential to consider 2.5mm stents as bail-out options only, reserving stents for cases where DCB is not sufficient.

Discussion and Q&A Highlights

  • Importance of data to back up the use of DCB, emphasizing the need for evidence-based practice.

  • Focus on small vessels due to existing data supporting DCB efficacy in this context.

  • Achieving optimal MSA (minimal stent area) is crucial for stenting.

    • IVUS cutoff: 5.5mm25.5 mm^2. for OCT: 4.5mm24.5mm^2.

    • Leaving stents at 2.32.4mmm22.3-2.4 mmm^2 is a disaster, highlighting the importance of appropriate stent sizing and deployment.

  • Address concerns about Absorb experience and lack of clinical data, providing context for its limited use.

    • More stringent criteria for vessel preparation needed for Absorb, emphasizing the technical challenges.

    • Data from registries in Japan and China suggested better outcomes with Absorb with better imaging and putting into larger vessels, highlighting specific conditions for success.

  • Data from the COMPARE ABSORB trial shows a higher target lesion failure rate in the absorbed group but that these were in super complex lesions, cautioning against its use in complex cases.

  • PALS concept will provide confidence and ability to decide whether or not to use DCB, aiding clinicians in appropriate patient selection and treatment strategy.