Expert Opinion: Optimising Stent Deployment in Contemporary Practice: The Role of Intracoronary Imaging and Non-compliant Balloons

Postdilatation after stent deployment during primary percutaneous coronary intervention: a systematic review and meta-analysis

BACKGROUND

The utilization of postdilatation in primary percutaneous coronary intervention (PCI) is feared to induce suboptimal coronary blood flow and compromise the outcome of the patients. This meta-analysis sought to verify whether postdilatation during primary PCI is associated with worse angiographic or long-term clinical outcomes.

METHODS

Systematic literature searches were conducted on PubMed, The Cochrane Library, ClinicalTrials.gov, EBSCO, and Europe PMC on 10 March 2024. Eligible studies reporting the outcomes of postdilatation among ST-segment elevation myocardial infarction patients were included. The primary outcome was no-reflow condition during primary PCI based on angiographic finding. The secondary clinical outcome was major adverse cardiovascular events (MACEs) comprising all-cause death, myocardial infarction, target vessel revascularization (TVR), and stent thrombosis.

RESULTS

Ten studies were finally included in this meta-analysis encompassing 3280 patients, which was predominantly male (76.6%). Postdilatation was performed in 40.7% cases. Postdilatation was associated with increased risk of no-reflow during primary PCI [Odd Ratio (OR) = 1.33, 95% Confidence Interval (CI): 1.12-1.58; P = .001)]. Conversely, postdilatation had a tendency to reduce MACE (OR = 0.70, 95% CI: 0.51-0.97; P = .03) specifically in terms of TVR (OR = 0.41, 95% CI: 0.22-0.74; P = .003). No significant differences between both groups in relation to mortality (OR = 0.58, 95% CI: 0.32-1.05; P = .07) and myocardial infarction (OR = 1.5, 95% CI: 0.78-2.89; P = .22).

CONCLUSIONS

Postdilatation after stent deployment during primary PCI appears to be associated with an increased risk of no-reflow phenomenon after the procedure. Nevertheless, postdilatation strategy has demonstrated a significant reduction in MACE over the course of long-term follow-up. Specifically, postdilatation significantly decreased the occurrence of TVR. Key messages: What is already known on this topic?  Optimizing stent deployment by performing postdilatation during percutaneous coronary intervention (PCI) is essential for long-term clinical outcomes. However, its application during primary PCI is controversial due to the fact that it may provoke distal embolization and worsen coronary blood flow. What this study adds?  In this systematic review and meta-analysis of 10 studies, we confirm that postdilatation during primary PCI is associated with worse coronary blood flow immediately following the procedure. On the contrary, this intervention proves advantageous in improving long-term clinical outcomes, particularly in reducing target vessel revascularization. How this study might affect research, practice, or policy?  Given the mixed impact of postdilatation during primary PCI, this strategy should only be applied selectively. Future research should focus on identifying patients who may benefit from such strategy.

Load-sharing characteristics of stenting and post-dilation in heavily calcified coronary artery

In this work, stenting in non-calcified and heavily calcified coronary arteries was quantified in terms of diameter-pressure relationships and load transfer from the balloon to the artery. The efficacy of post-dilation in non-calcified and heavily calcified coronary arteries was also characterized in terms of load sharing and the changes in tissue mechanics. Our results have shown that stent expansion exhibits a cylindrical shape in non-calcified lesions, while it exhibits a dog bone shape in heavily calcified lesions. Load-sharing analysis has shown that only a small portion of the pressure load (1.4 N, 0.8% of total pressure load) was transferred to the non-calcified lesion, while a large amount of the pressure load (19 N, 12%) was transferred to the heavily calcified lesion. In addition, the increasing inflation pressure (from 10 to 20 atm) can effectively increase the minimal lumen diameter (from 1.48 to 2.82 mm) of the heavily calcified lesion, the stress (from 1.5 to 8.4 MPa) and the strain energy in the calcification (1.77 mJ to 26.5 mJ), which are associated with the potential of calcification fracture. Results indicated that increasing inflation pressure can be an effective way to improve the stent expansion if a dog bone shape of the stenting profile is observed. Considering the risk of a balloon burst, our results support the design and application of the high-pressure balloon for post-dilation. This work also sheds some light on the stent design and choice of stent materials for improving the stent expansion at the dog bone region and mitigating stresses on arterial tissues.

Safety and Efficacy of Orbital Atherectomy in the All-Comer Population: Mid-Term Results of the Lower Silesian Orbital Atherectomy Registry (LOAR)

BACKGROUND

Coronary calcifications represent a challenging subset for the interventional cardiologist performing percutaneous coronary intervention (PCI) and are well-established risk factors for adverse outcomes. Adequate plaque modification prior to stent implantation is critical to achieve an optimal outcome following PCI. Recently, a novel orbital atherectomy device has been introduced into clinical practice to modify calcified plaques. We evaluated the mid-term safety and efficacy of OA in a high-risk "all-comers" population.

METHODS

We evaluated 96 consecutive patients with severely calcified coronary lesions who underwent PCI facilitated by the orbital atherectomy device.

RESULTS

In-hospital MACCE was 5.2% without target lesion revascularization. At 6-month follow-up, the MACCE rate was 10.4% with a concomitant TLR rate of 1%.

CONCLUSIONS

Our mid-term data showed good safety and efficacy of orbital atherectomy as a plaque-modifying tool in an all-comers cohort with severely calcified coronary lesions.

Load-sharing characteristics of stenting and post-dilation in heavily calcified coronary artery

In this work, stenting in non-calcified and heavily calcified coronary arteries was quantified in terms of diameter-pressure relationships and load transfer from the balloon to the artery. The efficacy of post-dilation in non-calcified and heavily calcified coronary arteries was also characterized in terms of load sharing and the changes in tissue mechanics. Our results have shown that stent expansion exhibits a cylindrical shape in non-calcified lesions, while it exhibits a dog bone shape in heavily calcified lesions. Load-sharing analysis has shown that only a small portion of the pressure load (1.4 N, 0.8% of total pressure load) was transferred to the non-calcified lesion, while a large amount of the pressure load (19 N, 12%) was transferred to the heavily calcified lesion. In addition, the increasing inflation pressure (from 10 to 20 atm) can effectively increase the minimal lumen diameter (from 1.48 mm to 2.82 mm) of the heavily calcified lesion, the stress (from 1.5 MPa to 8.4 MPa) the strain energy in the calcification (1.77 mJ to 26.5 mJ), which associated with the potential of calcification fracture. Results indicated that increasing inflation pressure can be an effective way to improve the stent expansion if a dog bone shape of the stenting profile is observed. Considering the risk of a balloon burst, our results support the design and application of the high-pressure balloon for post-dilation.

Clinical Outcomes of a Non-Compliant Balloon Dilatation Catheter: MOZEC™ NC Study

The present study sought to assess the clinical outcomes of the Mozec™ Non-compliant (NC) Rx PTCA balloon dilatation catheter (BDC) (Meril Life Sciences Pvt. Ltd., Vapi, India) for dilatation of coronary lesions. This was a post-marketing, single-centre, single-arm, retrospective study. In total, 57 patients who had undergone post-dilatation with the Mozec™ NC Rx PTCA balloon dilatation catheter were evaluated. The primary endpoint was procedural success defined as (i) successful delivery of the investigational device to and across the target lesion; (ii) successful inflation, deflation, and withdrawal of the investigational device; (iii) absence of vessel perforation, flow-limiting vessel dissection, increase in thrombolysis in myocardial infarction (TIMI) flow from baseline, clinically significant arrhythmia requiring medical treatment; and (iv) achievement of final TIMI flow grade 3 after percutaneous coronary intervention of the target lesion after single or multiple attempts to cross the target lesion. Procedural success was achieved in 57 (100%) patients. There were no incidences of major adverse cardiac events (MACE)/target lesion failure (TLF). Mozec™ NC Rx PTCA balloon dilatation catheter has demonstrated favourable outcomes for the dilatation of routine and complex coronary lesions in a small cohort, as evidenced by its 100% procedural success rate and absence of MACE.

Shockwave coronary intravascular lithotripsy system for heavily calcified de novo lesions and the need for a cost-effectiveness analysis

The optimal management for severely calcified coronary artery disease is multi-adjunctive. Different strategies with dedicated devices should be available in the cardiac catheterization laboratory with their selection depending on the nature of the calcific disease and its anatomical distribution. Shockwave Intravascular Lithotripsy (S-IVL) system offers a novel option for lesion preparation of heavily calcified plaques in coronary and peripheral vessels. S-IVL is based on the fundamental principles of lithotripsy, a technology that has been used to modify renal stones for over 30 years. Pulsatile mechanical energy is used to fragment selectively amorphous calcium, sparing soft tissue. S-IVL has the potential of more widespread adoption because of its proven safety, efficacy and operational simplicity, but cost-effectiveness of such advanced technology will need to be analyzed.

Procedural effectiveness with a focused force scoring angioplasty catheter: Procedural and clinical outcomes from the Scoreflex NC trial

BACKGROUND

The Scoreflex NC scoring angioplasty catheter is designed with a short rapid-exchange tip distal to a non-compliant, high-pressure balloon and an integral wire outside of the balloon, such that the guidewire and the integral wire act as scoring elements during balloon inflation. The external scoring elements enable a focal stress pattern facilitating expansion of resistant lesions at lower pressures using a focused force angioplasty effect.

METHODS

Patients undergoing elective percutaneous coronary intervention (PCI) were enrolled in a prospective, single-arm study conducted at 12 centers in the United States. The primary endpoint was device procedural success, defined as the composite of successful device delivery to the target lesion with balloon inflation and deflation; absence of vessel perforation, flow-limiting dissection or reduction in TIMI flow from baseline; and achievement of final TIMI 3 flow.

RESULTS

Among 200 patients (234 lesions), lesion complexities included: bifurcation disease (37.6%), moderate/severe calcification (36.6%), and total occlusions (5.0%). Successful delivery to the target lesion, inflation and removal of the balloon catheter was achieved in 95.5% of patients (191/200). Procedural success was achieved in 93.5% (187/200) of patients, and final TIMI 3 flow was observed in 99.0% of cases (198/200). No unanticipated device-related events occurred. In-hospital major adverse events were reported in 4.5% of patients (9/200), related to periprocedural myocardial infarction (8/200, 4.0%) and target lesion revascularization (1/200, 0.5%).

CONCLUSIONS

Among patients undergoing elective PCI and with varied lesion complexity, these results support the safety and effectiveness of a dilation strategy using the Scoreflex NC scoring catheter.

Current Treatment Modalities for Calcified Coronary Artery Disease: A Review Article Comparing Novel Intravascular Lithotripsy and Traditional Rotational Atherectomy

The coronary artery calcium score is considered the most useful marker for predicting coronary events. The high score reflects heavy calcification in the vessel, which is more challenging to treat with the percutaneous intervention (PCI). To prepare this type of heavily calcified lesion intravascular lithotripsy (IVL) technology can be used prior to PCI, which is based on the concept of converting electrical energy into mechanical energy. It harmlessly and selectively disrupts both the shallow and deep deposits of calcium. The balloon-based catheters of this system emit sonic waves that transfer to the adjacent tissue resulting in improvement in vessel compliance with the slightest soft tissue loss. Therefore, making the treatment of calcified lesions more feasible, effective, and also simplify complex lesions. The lesions considered for lithotripsy-enhanced balloon dilation include calcified coronary lesions and peripheral vasculature lesions. This article reviews the use of IVL in calcified coronary artery disease, its advantages, and disadvantages while comparing it with other techniques like high-pressure balloons and rotational atherectomy devices. A thorough search of databases like PubMed and Google Scholar was performed, which uncovered 35 peer review articles. Keywords utilized in the data search were calcified coronary artery disease, coronary lithotripsy, calcification, and calcified atherosclerotic plaque. According to rotational atherectomy and intravascular lithotripsy trials, the latter was safer, mainly by decreasing atheromatous embolization risk. Deciphering these studies, it seems like IVL is better at parameters like procedural and clinical success rate, acute lumen gain, and less residual stenosis except in-hospital major adverse cardiovascular events (MACE), which was better in rotational atherectomy (RA). However, when lesion crossings are present, the atherectomy technique is still considered as first-line therapy. In clinical practice, despite these encouraging data for treating calcified lesions, IVL is grossly underutilized because of substantial costs and perceived significant procedural risk effects on the cardiac rhythm like causing 'shock topics' and asynchronous cardiac pacing. More longer-term clinical data and extensive researches are required to validate its safety and efficiency.

Utility of a novel high pressure non-compliant balloon for tibial atherosclerotic lesions in Asian patients with chronic limb threatening ischaemia

Background: The aim was to evaluate the safety and efficacy of a high pressure, non-compliant balloon in the treatment of infrapopliteal occlusive disease in Asian patients with chronic limb threatening ischaemia (CLTI) from Singapore. Patients and methods: Prospective, multi-centre, single arm, non-randomized study. Immediate technical success, 6-month primary vessel patency (determined by Duplex ultrasonography), limb salvage, one-year clinically driven target lesion re-intervention (TLR) and amputation free survival (AFS) were the efficacy endpoints of interest. Results: 86 patients (63% males, mean age 68.9 ± 9.9 years) were enrolled over a 15-month period. Diabetes mellitus (DM) and end-stage renal failure (ESRF) were present in 94% and 38% of patients respectively. All had some degree of tissue loss at baseline (Rutherford scale 5 and 6 = 91% and 9% respectively). Of the 86 legs, 72% had 3 crural vessel disease and 84% had moderate/severe vessel wall calcification. 90% had > = 1 TASC D tibial lesion. Acute technical success was 89%. One month mortality was 3.5% and one-year freedom from TLR was 91%. 6-month tibial patency was 73%. 54/66 (82%) patients had at least one target treated tibial artery open at 6 months. A lower baseline toe pressure (OR 1.03, 95%CI 1.00-1.05) and elastic recoil post angioplasty (OR 0.20, 95%CI 0.05-0.79) were associated with a worse 6 month tibial patency. One-year AFS was 67%. 47/66 (71%) patients had a clinical improvement of at least one Rutherford class at 6 months and 52/59 (88%) experienced complete wound healing at 12 months. Conclusions: Use of a high pressure non-compliant balloon is safe and efficacious in treating highly complex infra-popliteal atherosclerotic lesions in an otherwise challenging population of CLTI patients with a high incidence of DM and ESRF. It is associated with highly satisfactory acute technical success, 6-month target lesion patency and one-year limb salvage.

Uncrossable and undilatable lesions-A practical approach to optimizing outcomes in PCI

Uncrossable lesions are those that cannot be crossed with a balloon after successful guidewire crossing. These lesions are challenging and are commonly encountered in tortuous and calcified arteries as well as chronic total occlusions. They are the second most common barrier to successful PCI in CTO intervention after inability to cross the CTO segment with a guidewire. Procedures involving balloon uncrossable lesions during routine and CTO PCI utilise longer procedural times, radiation dose and contrast volumes with a lower likelihood of procedural success. In this article, we describe a pragmatic approach of managing balloon uncrossable lesions utilising the most contemporary equipment available in an algorithmic fashion beginning with simple, cost effective techniques right up to complex strategies for advanced operators. In addition, some of these lesions, even when crossed by any technique, they may remain difficult to dilate and prepare for stent insertion. We describe an approach of how to manage these undilatable lesions.

Contemporary Approach to Heavily Calcified Coronary Lesions

Percutaneous treatment of heavily calcified coronary lesions still represents a challenge for interventional cardiology, with higher risk of immediate complications, late failure due to stent underexpansion and malapposition, and consequently poor clinical outcome. Good characterisation of calcium distribution with multimodal imaging is important to improve the successful treatment of these lesions. The use of traditional or new dedicated devices for the treatment of calcified lesions allows better lesion preparation; therefore, it is important that we know the different mechanisms and technical features of these devices.

How Should We Treat Heavily Calcified Coronary Artery Disease in Contemporary Practice? From Atherectomy to Intravascular Lithotripsy

Heavily calcified and densely fibrotic coronary lesions continue to represent a challenge for percutaneous coronary intervention (PCI), as they are difficult to dilate, and it is difficult to deliver and implant drug-eluting stents (DES) properly. Poor stent deployment is associated with high rates of periprocedural complications and suboptimal long-term clinical outcomes. Thanks to the introduction of several adjunctive PCI tools, like cutting and scoring balloons, atherectomy devices, and to the novel intravascular lithotripsy technology, the treatment of such lesions has become increasingly feasible, predictable and safe. A step-wise progression of strategies is described for coronary plaque modification, from well-recognised techniques to techniques that should only be considered when standard manoeuvres have proven unsuccessful. We highlight these techniques in the setting of clinical examples how best to apply them through better patient and lesion selection, with the main objective of optimising DES delivery and implantation, and subsequent improved outcomes.