Drug-Eluting Stenting

Technological Advances Are Associated With Better Clinical Outcomes of Percutaneous Coronary Intervention in Patients With Unprotected Left Main Disease

BACKGROUND

Few large-scale studies have evaluated the effectiveness of percutaneous coronary intervention (PCI) technological advances in the treatment of patients with unprotected left main coronary artery disease (LM-CAD). We aim to identify independent factors that affect the prognosis of PCI in patients with unprotected LM-CAD and to assess the impact of PCI technological advances on long-term clinical outcomes.

METHODS AND RESULTS

A total of 4512 consecutive patients who underwent unprotected LM-CAD PCI at Fuwai Hospital from 2004 to 2016 were enrolled. Multivariable Cox proportional hazards model was used to identify which techniques can independently affect the incidence of major adverse cardiac events (MACEs; a composite of cardiac death, myocardial infarction, or target vessel revascularization). The incidence of 3-year MACEs was 9.0% (406/4512). Four new PCI techniques were identified as the independent protective factors of MACEs, including second-generation drug-eluting stents (hazard ratio [HR], 0.61 [95% CI, 0.37-0.99]), postdilatation (HR, 0.75 [95% CI, 0.59-0.94]), final kissing balloon inflation (HR, 0.78 [95% CI, 0.62-0.99]), and using intravascular ultrasound (HR, 0.78 [95% CI, 0.63-0.97]). The relative hazard of 3-year MACEs was reduced by ≈50% with use of all 4 techniques compared with no technique use (HR, 0.53 [95% CI, 0.32-0.87]).

CONCLUSIONS

PCI technological advances including postdilatation, second-generation drug-eluting stent, final kissing balloon inflation, and intravascular ultrasound guidance were associated with improved clinical outcomes in patients who underwent unprotected LM-CAD PCI.

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.

Quantitative Coronary Angiography vs Intravascular Ultrasonography to Guide Drug-Eluting Stent Implantation: A Randomized Clinical Trial

Importance

Although intravascular ultrasonography (IVUS) guidance promotes favorable outcomes after percutaneous coronary intervention (PCI), many catheterization laboratories worldwide lack access.

Objective

To investigate whether systematic implementation of quantitative coronary angiography (QCA) to assist angiography-guided PCI could be an alternative strategy to IVUS guidance during stent implantation.

Design, Setting, and Participants

This randomized, open-label, noninferiority clinical trial enrolled adults (aged ≥18 years) with chronic or acute coronary syndrome and angiographically confirmed native coronary artery stenosis requiring PCI. Patients were enrolled in 6 cardiac centers in Korea from February 23, 2017, to August 23, 2021, and follow-up occurred through August 25, 2022. All principal analyses were performed according to the intention-to-treat principle.

Interventions

After successful guidewire crossing of the first target lesion, patients were randomized in a 1:1 ratio to receive either QCA- or IVUS-guided PCI.

Main Outcomes and Measures

The primary outcome was target lesion failure at 12 months, defined as a composite of cardiac death, target vessel myocardial infarction, or ischemia-driven target lesion revascularization. The trial was designed assuming an event rate of 8%, with the upper limit of the 1-sided 97.5% CI of the absolute difference in 12-month target lesion failure (QCA-guided PCI minus IVUS-guided PCI) to be less than 3.5 percentage points for noninferiority.

Results

The trial included 1528 patients who underwent PCI with QCA guidance (763; mean [SD] age, 64.1 [9.9] years; 574 males [75.2%]) or IVUS guidance (765; mean [SD] age, 64.6 [9.5] years; 622 males [81.3%]). The post-PCI mean (SD) minimum lumen diameter was similar between the QCA- and IVUS-guided PCI groups (2.57 [0.55] vs 2.60 [0.58] mm, P = .26). Target lesion failure at 12 months occurred in 29 of 763 patients (3.81%) in the QCA-guided PCI group and 29 of 765 patients (3.80%) in the IVUS-guided PCI group (absolute risk difference, 0.01 percentage points [95% CI, -1.91 to 1.93 percentage points]; hazard ratio, 1.00 [95% CI, 0.60-1.68]; P = .99). There was no difference in the rates of stent edge dissection (1.2% vs 0.7%, P = .25), coronary perforation (0.2% vs 0.4%, P = .41), or stent thrombosis (0.53% vs 0.66%, P = .74) between the QCA- and IVUS-guided PCI groups. The risk of the primary end point was consistent regardless of subgroup, with no significant interaction.

Conclusions and Relevance

Findings of this randomized clinical trial indicate that QCA and IVUS guidance during PCI showed similar rates of target lesion failure at 12 months. However, due to the lower-than-expected rates of target lesion failure in this trial, the findings should be interpreted with caution.

Trial Registration

ClinicalTrials.gov Identifier: NCT02978456.

Impact of post-dilatation on post-procedural physiology, microcirculatory resistance, and target vessel failure in STEMI patients undergoing PPCI: A single-center experience

BACKGROUND

Suboptimal stent deployment is frequently observed in ST-segment elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PPCI). This study sought to investigate whether these patients could benefit from post-dilatation with respect to post-procedural physiology, microcirculatory resistance, and long-term clinical outcomes.

METHODS

This was a retrospective study of consecutive STEMI patients who underwent successful stent implantation during PPCI from February 2016 to November 2021. Post-procedural physiology and microcirculatory resistance were assessed by Murray law-based quantitative flow ratio (μQFR) and angiographic microcirculatory resistance (AMR), respectively. The primary outcome was target vessel failure (TVF), a composite of cardiac death, target vessel-oriented myocardial infarction, and clinically driven target vessel revascularization.

RESULTS

A total of 671 patients (671 culprit vessels) were included. Post-dilatation was selectively performed in 430 (64.1%) culprit vessels, resulting in a 0.02 (interquartile range: 0.00-0.05, p < 0.001) increase in post-procedural μQFR but no significant impact on AMR. During a median follow-up of 2.8 years (interquartile range: 1.4-3.0 years), TVF occurred in 47 (7.0%) patients. Post-dilatation demonstrated a trend toward a reduction in TVF (5.3% vs. 10.0%; adjusted hazard ratio: 0.60, 95% confidence interval: 0.33-1.09, p = 0.094), mainly driven by a lower incidence of clinically driven target vessel revascularization (1.6% vs. 4.1%; adjusted hazard ratio: 0.32, 95% confidence interval: 0.11-0.90, p = 0.030).

CONCLUSIONS

In STEMI patients undergoing PPCI, selective post-dilatation was associated with improved post-procedural physiological results and a trend toward less TVF events without aggravating microcirculatory resistance.

Results of systematic patient outcome monitoring: Does post-dilatation during angiography-guided percutaneous coronary intervention improve clinical outcomes?

OBJECTIVES

This study evaluates clinical outcomes after implementing a liberal post-dilatation strategy during PCI.

BACKGROUND

Post-dilatation after percutaneous coronary intervention (PCI) is performed to achieve optimal stent expansion and reduce complications. However, its prognostic effects are unclear and conflicting.

METHODS

This study is a pre-post-intervention analysis of two cohorts, before (2015-2017) and after (2018-2020) implementation of a liberal post-dilatation strategy. The primary end point consisted of major adverse cardiovascular events (MACE) at 30 days. Secondary end points consisted of the individual components of the primary end point as well as 1 year mortality and target vessel revascularization.

RESULTS

A total of 10,153 patients were included: 5,383 in the pre-cohort and 4,770 in the post-cohort. The 30-day MACE was 5.00% in the pre-cohort and 4.09% in the post-cohort (p = 0.008; OR 0.75 (CI 0.61-0.93)). There was a significant difference between the pre- and post-cohort in 30-day mortality, respectively, 2.91% and 2.25% (p = .01; OR 0.70 (CI 0.53-0.93)), and MI at 30 days, 1.17% versus 0.59% (p = .003; OR 0.49 (CI 0.31-0.78)). At 1 year, there was a significant difference in mortality between the pre-cohort, 5.84%, and post-cohort, 5.19% (p = .02; OR 0.79 (CI 0.66-0.96)).

CONCLUSIONS

A liberal post-dilatation strategy after PCI was associated with a significant decrease in 30-day MACE, 30-day MI, 30-day mortality, and 1-year mortality. Future studies are warranted to validate the causality between post-dilatation and improvement of clinical outcomes.

Optical Coherence Tomography-Guided Percutaneous Coronary Intervention: Practical Application

Optical coherence tomography (OCT) provides high-resolution imaging of coronary arteries and can be used to optimize percutaneous coronary intervention (PCI). Intracoronary OCT, however, has had limited adoption in clinical practice. Novelty and relative complexity of OCT interpretation compared with the more established intravascular ultrasound, lack of a standardized algorithm for PCI guidance, paucity of data from randomized trials, and lack of rebate for intravascular imaging have contributed to the modest practical adoption of OCT. We provide a practical step-by-step guide on how to use OCT in PCI, including device set-up, simplified image interpretation, and an algorithmic approach for PCI. optimization.

Intravascular Ultrasound-Guided Percutaneous Coronary Intervention: Evidence and Clinical Trials

The intravascular ultrasound (IVUS)-guided percutaneous coronary intervention (PCI) that was associated with improved post-procedural outcomes and long-term clinical outcomes has shown benefits not only in patients with complex lesions but also with simplex lesions. However, the use of IVUS during PCI remains low; therefore, further prospective, randomized, controlled trials are required to strengthen the recommendations and consequently expand its usage. The aim of this review is to discuss the previous evidences and clinical trials regarding IVUS-guided PCI and to discover the necessity for future studies to broaden its use in the real-world clinical practice.

The MLD MAX OCT algorithm: An imaging-based workflow for percutaneous coronary intervention

Although extensive clinical data support the utility of intravascular imaging to guide and optimize outcomes following percutaneous coronary interventions (PCI), clinical adoption remains limited. One of the primary reasons for limited utilization may be a lack of standardization on how to best integrate the data provided by intravascular imaging practically. Optical coherence tomography (OCT) offers a high-resolution intravascular imaging modality with integrated software automation that allows for incorporation of OCT into the routine workflow of PCIs. We suggest use of an algorithm called MLD MAX to incorporate OCT for imaging-guided interventions: the baseline OCT imaging run is intended to facilitate procedural planning and strategizing, consisting of assessment for predominant lesion morphology (M), measurement for stent length (L) and determination of stent diameter (D); the post-PCI OCT imaging run is designated for assessment of need for further optimization of stent result, and consists of analysis for medial dissections (M), adequate stent apposition (A) and stent expansion (X). Incorporation of the MLD MAX algorithm into daily practice guides an efficient and easily-memorable workflow for optimized PCI procedures.

Definition of Optimal Optical Coherence Tomography-Based Stent Expansion Criteria: In-Stent Minimum Lumen Area Versus Residual Stent Underexpansion

BACKGROUND

The mismatch between in-stent minimum lumen area (sMLA) and reference vessel lumen area, defined as stent underexpansion (SU), could be an important determinant of stent failure. We tested the clinical predictive value of absolute sMLA in comparison to relative SU in the context of the CLI-OPCI (Centro Per La Lotta Contro L'Infarto-Optimisation of Percutaneous Coronary Intervention) project registry.

METHODS

We retrospectively analyzed end procedural optical coherence tomography findings in 1211 patients (1422 lesions) undergoing percutaneous coronary intervention, assessing the prevalence and magnitude of residual SU and exploring correlation with outcome in comparison with sMLA.

RESULTS

In our series, both sMLA and SU were related to vessel size and anatomic lesion complexity. When compared with patients without adverse event at follow-up, those experiencing device-oriented cardiovascular events (composite of cardiac death, target vessel myocardial infarction, target lesion revascularization, and stent thrombosis) showed a lower sMLA (5.6±2.1 versus 6.1±2.1 mm²; P=0.011) but a comparable degree of SU (11.6±14.1% versus 11.2±13.3%; P=0.734). The prespecified cutoff value of sMLA <4.5 mm², documented in 23.8% of cases, was confirmed as independent outcome predictor for device-oriented cardiovascular events (hazard ratio [HR], 2.05 [95% CI, 1.5-2.9]) including target lesion revascularization (HR, 2.43 [95% CI, 1.7-3.5]) and stent thrombosis (HR, 3.23 [95% CI, 1.7-6.3]). A residual SU of 10%, 20%, and 30% was observed in 38.0%, 18.2%, and 7.6% of cases, respectively. No grade of residual SU significantly increased the risk of stent failure, unless if an SU >20% was associated with an sMLA <4.5 mm² (HR, 3.11 [95% CI, 1.7-5.6]). Finally, an association between stent overexpansion (ie, >110%) and device-oriented cardiovascular events was also observed (HR, 1.60 [95% CI, 1.1-2.3]).

CONCLUSIONS

Final absolute sMLA and not relative SU was associated with an increased risk of stent failure. A variable grade of SU was common, but it resulted in being clinically relevant only when associated with an sMLA <4.5 mm².

Microvascular and Prognostic Effect in Lesions With Different Stent Expansion During Primary PCI for STEMI: Insights From Coronary Physiology and Intravascular Ultrasound

Background

While coronary stent implantation in ST-elevation myocardial infarction (STEMI) can mechanically revascularize culprit epicardial vessels, it might also cause distal embolization. The relationship between geometrical and functional results of stent expansion during the primary percutaneous coronary intervention (pPCI) is unclear.

Objective

We sought to determine the optimal stent expansion strategy in pPCI using novel angiography-based approaches including angiography-derived quantitative flow ratio (QFR)/microcirculatory resistance (MR) and intravascular ultrasound (IVUS).

Methods

Post-hoc analysis was performed in patients with acute STEMI and high thrombus burden from our prior multicenter, prospective cohort study (ChiCTR1800019923). Patients aged 18 years or older with STEMI were eligible. IVUS imaging, QFR, and MR were performed during pPCI, while stent expansion was quantified on IVUS images. The patients were divided into three subgroups depending on the degree of stent expansion as follows: overexpansion (>100%), optimal expansion (80%−100%), and underexpansion (<80%). The patients were followed up for 12 months after PCI. The primary endpoint included sudden cardiac death, myocardial infarction, stroke, unexpected hospitalization or unplanned revascularization, and all-cause death.

Results

A total of 87 patients were enrolled. The average stent expansion degree was 82% (in all patients), 117% (in overexpansion group), 88% (in optimal expansion), and 75% (in under-expansion). QFR, MR, and flow speed increased in all groups after stenting. The overall stent expansion did not affect the final QFR (p = 0.08) or MR (p = 0.09), but it reduced the final flow speed (−0.14 cm/s per 1%, p = 0.02). Under- and overexpansion did not affect final QFR (p = 0.17), MR (p = 0.16), and flow speed (p = 0.10). Multivariable Cox analysis showed that stent expansion was not the risk factor for MACE (hazard ratio, HR = 0.97, p = 0.13); however, stent expansion reduced the risk of MACE (HR = 0.95, p = 0.03) after excluding overexpansion patients. Overexpansion was an independent risk factor for no-reflow (HR = 1.27, p = 0.02) and MACE (HR = 1.45, p = 0.007). Subgroup analysis shows that mild underexpansion of 70%−80% was not a risk factor for MACE (HR = 1.11, p = 0.08) and no-reflow (HR = 1.4, p = 0.08); however, stent expansion <70% increased the risk of MACE (HR = 1.36, p = 0.04).

Conclusions

Stent expansion does not affect final QFR and MR, but it reduces flow speed in STEMI. Appropriate stent underexpansion of 70–80% does not seem to be associated with short-term prognosis, so it may be tolerable as noninferior compared with optimal expansion. Meanwhile, overexpansion and underexpansion of <70% should be avoided due to the independent risk of MACEs and no-reflow events.

Quantitative coronary angiography versus intravascular ultrasound guidance for drug-eluting stent implantation (GUIDE-DES): study protocol for a randomised controlled non-inferiority trial

INTRODUCTION

Angiography remains the gold standard for guiding percutaneous coronary intervention (PCI). However, it is prone to suboptimal stent results due to the visual estimation of coronary measurements. Although the benefit of intravascular ultrasound (IVUS)-guided PCI is becoming increasingly recognised, IVUS is not affordable for many catheterisation laboratories. Thus, a more practical and standardised angiography-based approach is necessary to support stent implantation.

METHODS AND ANALYSIS

The Quantitative Coronary Angiography versus Intravascular Ultrasound Guidance for Drug-Eluting Stent Implantation trial is a randomised, investigator-initiated, multicentre, open-label, non-inferiority trial comparing the quantitative coronary angiography (QCA)-guided PCI strategy with IVUS-guided PCI in all-comer patients with significant coronary artery disease. A novel, standardised, QCA-based PCI protocol for the QCA-guided group will be provided to all participating operators, while the PCI optimisation criteria will be predefined for both strategies. A total of 1528 patients will be randomised to either group at a 1:1 ratio. The primary endpoint is the 12-month cumulative incidence of target-lesion failure defined as a composite of cardiac death, target-vessel myocardial infarction or ischaemia-driven target-lesion revascularisation. Clinical follow-up assessments are scheduled at 1, 6 and 12 months for all patients enrolled in the study.

ETHICS AND DISSEMINATION

Ethics approval for this study was granted by the Institutional Review Board of Asan Medical Center (no. 2017-0060). Informed consent will be obtained from every participant. The study findings will be published in peer-reviewed journal articles and disseminated through public forums and academic conference presentations. Cost-effectiveness and secondary imaging analyses will be shared in secondary papers.

TRIAL REGISTRATION NUMBER

NCT02978456.

Is Routine Postdilation During Angiography-Guided Stent Implantation as Good as Intravascular Ultrasound Guidance?: An Analysis Using Data From IVUS-XPL and ULTIMATE

BACKGROUND

There are 2 competing approaches to optimize drug-eluting stent implantation: angiography-guided routine postdilation or intravascular ultrasound (IVUS) guidance.

METHODS

From the pooled data of 2 randomized trials, IVUS-XPL (Impact of Intravascular Ultrasound Guidance on the Outcomes of Xience Prime Stents in Long Lesions) and ULTIMATE (Intravascular Ultrasound Guided Drug Eluting Stents Implantation in All-Comers Coronary Lesions), that compared IVUS- versus angiography-guided drug-eluting stent implantation, we compared 1037 patients (1265 lesions) with IVUS-guided postdilation, 905 patients (1170 lesions) with angiography-guided postdilation, and 383 patients (397 lesions) with angiography-guided drug-eluting stent implantation without postdilation as a reference group; all patients required ≥28 mm long stents. The primary end point was composite of cardiac death, target lesion-related myocardial infarction, or ischemia-driven target lesion revascularization at 3 years.

RESULTS

Postintervention quantitative coronary angiography-based minimum lumen diameter was not different between the angiography guidance with postdilation versus the angiography guidance without postdilation group (2.5±0.4 mm versus 2.5±0.4 mm; P=0.367). However, it was larger in the IVUS guidance with postdilation versus the angiography guidance without postdilation group (2.6±0.5 mm versus 2.5±0.4 mm; P=0.046), and also in the IVUS guidance with postdilation versus the angiography guidance with postdilation group (2.6±0.5 mm versus 2.5±0.4 mm; P<0.001). The rate of the primary end point was not different between the angiography guidance with postdilation versus the angiography guidance without postdilation group (8.6% versus 9.8%; hazard ratio, 0.86 [95% CI, 0.58-1.29]; P=0.473). However, it was lower after IVUS guidance with postdilation versus angiography guidance without postdilation (4.5% versus 9.8%; hazard ratio, 0.44 [95% CI, 0.28-0.68]; P<0.001) and also after IVUS guidance with postdilation versus angiography guidance with postdilation (4.5% versus 8.6%; hazard ratio, 0.51 [95% CI, 0.35-0.74]; P<0.001).

CONCLUSIONS

In patients undergoing long drug-eluting stent implantation, IVUS-guided postdilation was associated with improved long-term clinical outcomes, unlike angiography-guided postdilation.

Influence of balloon design, plaque material composition, and balloon sizing on acute post angioplasty outcomes: An implicit finite element analysis

In this work we propose a generic modeling approach for simulating percutaneous transluminal angioplasty (PTA) endovascular treatment, and evaluating the influence of balloon design, plaque composition, and balloon sizing on acute post-procedural outcomes right after PTA, without stent implantation. Clinically-used PTA balloons were classified into two categories according to their compliance characteristics, and were modeled correspondingly. Self-defined elastoplastic constitutive laws were implemented within the plaque and artery models, after calibration based on experimental and clinical data. Finite element method (FEM) implicit solver was used to simulate balloon inflation and deflation. Besides balloon profile at max inflation, results are mainly assessed in terms of the elastic recoil ratio (ERR) and lumen gain ratio (LGR) obtained immediately after PTA. No variations in ERR nor LGR values were detected when the balloon design changed, despite the differences observed in their profile at max inflation. Moreover, LGR and ERR inversely varied with the augmentation of calcification level within the plaque (-11% vs. +4% respectively, from fully lipidic to fully calcified plaque). Furthermore, results showed a direct correlation between balloon sizing and LGR and ERR, with noticeably higher rates of change for LGR (+18% and +2% for LGR and ERR respectively for a calcified plaque and a balloon pressure increasing from 10 to 14 atm). However a larger LGR comes with a higher risk of arterial rupture. This proposed methodology opens the way for evaluation of angioplasty balloon selections towards clinical procedure optimization.

Intracoronary optical coherence tomography: state of the art and future directions

Optical coherence tomography (OCT) has been increasingly utilised to guide percutaneous coronary intervention (PCI). Despite the diagnostic utility of OCT, facilitated by its high resolution, the impact of intracoronary OCT on clinical practice has thus far been limited. Difficulty in transitioning from intravascular ultrasound (IVUS), complex image interpretation, lack of a standardised algorithm for PCI guidance, and paucity of data from prospective clinical trials have contributed to the modest adoption. Herein, we provide a comprehensive up-do-date overview on the utility of OCT in coronary artery disease, including technical details, device set-up, simplified OCT image interpretation, recognition of the imaging artefacts, and an algorithmic approach for using OCT in PCI guidance. We discuss the utility of OCT in acute coronary syndromes, provide a summary of the clinical trial data, list the work in progress, and discuss the future directions.

Effects of stent postdilatation during primary PCI for STEMI: Insights from coronary physiology and optical coherence tomography

OBJECTIVES

This study aimed to assess the impact of stent optimization by NC-balloon postdilatation (PD) during primary-PCI for STEMI with the use of coronary physiology and intracoronary imaging.

METHODS

This was a prospective observational study (ClinicalTrials.gov:NCT02788396). Optical coherence tomography (OCT) and physiological measurements were performed immediately before and after PD with the operators blinded to all measurements. The index of microcirculatory resistance (IMR), coronary flow reserve (CFR) and fractional flow reserve (FFR) were measured. OCT analysis was performed for assessment of stent expansion, malapposition, in-stent plaque-thrombus prolapse (PTP) and stent-edge dissections (SED). The change in IMR before and after PD as a measure of microvascular injury was the primary objective of the study.

RESULTS

Thirty-two STEMI patients undergoing primary-PCI had physiological measurements before and after PD. All patients received second-generation DES (diameter 3.1 ± 0.5 mm, length 29.9 ± 10.7 mm) and postdilatation with NC-balloons (diameter 3.6 ± 0.6 mm, inflation pressure 19.3 ± 2.0 atm). IMR (44.9 ± 25.6 vs. 48.8 ± 34.2, p = 0.26) and CFR (1.60 ± 0.89 vs. 1.58 ± 0.71, p = 0.87) did not change, while FFR increased after PD (0.91 ± 0.08 vs. 0.93 ± 0.06, p = 0.037). At an individual patient level, IMR increased in half of the cases. PD improved significantly absolute and relative stent expansion, reduced malapposition, and increased PTP. There was no difference in clinically relevant SED.

CONCLUSION

In this exploratory, hypothesis-generating study, postdilatation during primary-PCI for STEMI improved stent expansion, apposition and post-PCI FFR, without a significant effect on coronary microcirculation overall. Nevertheless, IMR increased in a group of patients and larger studies are warranted to explore predictors of microcirculatory response to postdilatation.

The Clinical and Angiographic Outcomes of Postdilation after Percutaneous Coronary Intervention in Patients with Acute Coronary Syndrome: A Systematic Review and Meta-Analysis

OBJECTIVE

The effect of postdilation in patients with acute coronary syndrome is still controversial. This meta-analysis aims to analyze the clinical and angiographic outcomes of postdilation after percutaneous coronary intervention in patients with acute coronary syndrome.

METHODS

PubMed, Embase, the Cochrane Library, Web of Science, CNKI, and Wangfang databases were searched from inception to August 30, 2020. Eligible studies from acute coronary syndrome patients treated with postdilation were included. The primary clinical outcome was major adverse cardiovascular events (MACE), the secondary clinical outcomes comprised all-cause death, stent thrombosis, myocardial infarction, and target vessel revascularization, and the angiographic outcomes were no reflow and slow reflow.

RESULTS

11 studies met inclusion criteria. In clinical outcomes, our pooled analysis demonstrated that the postdilation had a tendency of decreasing MACE (OR = 0.67, 95% CI 0.45-1.00; P = 0.05) but significantly increased all-cause death (OR = 1.49, 95% CI 1.05-2.12; P = 0.03). No significant difference existed in stent thrombosis (OR = 0.71, 95% CI 0.40-1.26; P = 0.24), myocardial infarction (OR = 1.40, 95% CI 0.51-3.83; P = 0.51), and target vessel revascularization (OR = 0.61, 95% CI 0.21-1.80; P = 0.37) between postdilation and non-postdilation groups. In angiographic outcomes, there were no significant differences in no reflow (OR = 1.19, 95% CI 0.54-2.65; P = 0.66) and slow reflow (OR = 1.12, 95% CI 0.93-1.35; P = 0.24) between two groups.

CONCLUSIONS

The postdilation tends to reduce the risk of MACE but significantly increases all-cause death, without significantly affecting stent thrombosis, myocardial infarction, target vessel revascularization, and coronary TIMI flow grade. However, more randomized controlled trials are required for investigating the effect of postdilation for patients with acute coronary syndrome (registered by PROSPERO, CRD42020160748).

Non-compliant and compliant balloons for endovascular rescue therapy of cerebral vasospasm after spontaneous subarachnoid haemorrhage: experiences of a single-centre institution with radiological follow-up of the treated vessel segments

BACKGROUND

For endovascular rescue therapy (ERT) of cerebral vasospasm (CVS) due to spontaneous subarachnoid haemorrhage (sSAH), non-compliant (NCB) and compliant (CB) balloons are used with both balloon types bearing the risk of vessel injury due to specific mechanical properties. Although severe delayed arterial narrowing after transluminal balloon angioplasty (TBA) for CVS has sporadically been described, valid data concerning incidence and relevance are missing. Our aim was to analyse the radiological follow-up (RFU) of differently TBA-treated arteries (CB or NCB).

METHODS

Twelve patients with utilisation of either NCB or CB for CVS were retrospectively analysed for clinical characteristics, ERT, functional outcome after 3 months and RFU. Compared with the initial angiogram, we classified delayed arterial narrowing as mild, moderate and severe (<30%, 30%-60%, respectively >60% calibre reduction).

RESULTS

Twenty-three arteries were treated with CB, seven with NCB. The median first RFU was 11 months after TBA with CB and 10 after NCB. RFU was performed with catheter angiography in 18 arteries (78%) treated with CB and in five (71%) after NCB; magnetic resonance angiography was acquired in five vessels (22%) treated with CB and in two (29%) after NCB. Mild arterial narrowing was detected in three arteries (13%) after CB and in one (14%) after NCB. Moderate or severe findings were neither detected after use of CB nor NCB.

CONCLUSION

We found no relevant delayed arterial narrowing after TBA for CVS after sSAH. Despite previous assumptions that CB provides for more dilatation in segments adjacent to CVS, we observed no disadvantages concerning long-term adverse effects. Our data support TBA as a low-risk treatment option.

The influence of angioplasty balloon sizing on acute post-procedural outcomes: a Finite Element Analysis

Atherosclerosis is one of the most common vascular pathologies in the world. Among the most commonly performed endovascular treatments, percutaneous transluminal angioplasty (PTA) has been showing significantly positive clinical outcomes. Due to the complex geometries, material properties and interactions that characterize PTA procedures, finite element analyses of acute angioplasty balloon deployment are limited. In this work, finite element method (FEM) was used to simulate the inflation and deflation of a semi-compliant balloon within the 3D model of a stenosed artery with two different plaque types (lipid and calcified). Self-defined constitutive models for the balloon and the plaque were developed based on experimental and literature data respectively. Balloon deployment was simulated at three different inflation pressures (10, 12 and 14 atm) within the two plaque types. Balloon sizing influence on the arterial elastic recoil obtained immediately after PTA was then investigated. The simulated results show that calcified plaques may lead to higher elastic recoil ratios compared to lipid stenosis, when the same balloon inflation pressures are applied. Also, elastic recoil increases for higher balloon inflation pressure independent of the plaque type. These findings open the way for a data-driven assessment of angioplasty balloon sizing selection and clinical procedures optimization.Clinical Relevance- The FE model developed in this work aims at providing quantitative evaluation of recoil after balloon angioplasty. It may be useful for both manufacturers and clinicians to improve efficiency of angioplasty balloon device design and sizing selection with respect to plaque geometry and constitution, consequently enhancing clinical outcomes.

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.

Additional postdilatation using noncompliant balloons after everolimus-eluting stent implantation: Results of the PRESS trial

Background

There are limited data on the clinical value of routine postdilatation using noncompliant balloons after contemporary drug‐eluting stent implantation.

Hypothesis

Additional postdilatation using noncompliant balloons after everolimus‐eluting stent implantation could provide better clinical outcomes.

Methods

We randomly assigned 1774 patients with coronary artery disease to undergo additional high‐pressure postdilatation using noncompliant balloons and moderate‐pressure dilatation using stent balloons after everolimus‐eluting stent implantation. The primary endpoint was a composite of death, myocardial infarction (MI), stent thrombosis, and target vessel revascularization (TVR) 2 years after randomization.

Results

The study was discontinued early owing to slow enrollment. In total, 810 patients (406 patients in the high pressure group and 404 in the moderate pressure group) were finally enrolled. At 2 years, the primary endpoint occurred in 3.6% of patients in the high pressure group and in 4.4% of those in the moderate pressure group (P = .537). In addition, no significant differences were observed between the two groups in the occurrence of an individual end point of death (0.8% in the high pressure group vs 1.5% in the moderate group, P = .304), MI (0.2% vs 0.5%, P = .554), stent thrombosis (0% vs 0.2%, P = .316), or TVR (2.8% vs 2.6%, P = .880).

Conclusions

The strategy of routine postdilatation using noncompliant balloons after everolimus‐eluting stent implantation did not provide incremental clinical benefits.

Impact of Postdilation on Intervention Success and Long-Term Major Adverse Cardiovascular Events (MACE) among Patients with Acute Coronary Syndromes

Postdilation is frequently used during coronary interventions to prevent stent malapposition. Currently there are contradictory findings regarding the benefits of postdilation for both intraprocedural and long-term outcomes. We evaluated the impact of postdilation among patients who presented with acute coronary syndromes (ACS) and underwent percutaneous coronary interventions (PCI). A total of 258 consecutive patients who presented with ACS and underwent PCI were included in the study. The patients were followed up for 25±1.7 months for the occurrence of major adverse cardiovascular events (MACE). During follow-up, 65 patients (25.2%) had MACE. Among patients without MACE, intracoronary nitrate infusion was less frequently used (P=0.005), myocardial blush grade was higher (P<0.001), and a drug-eluting stent was more frequently used (P=0.005). No significant differences were noted between groups regarding the predilation, recurrent dilation, postdilation, and other angiographic characteristics. In multivariate analysis, female sex (P=0.047), myocardial blush grade (P=0.038), previous coronary artery disease (P=0.030), and peak troponin level (P=0.002) were found to be predictors of MACE. In patients who were treated with PCI for ACS, performing postdilation did not predict final Thrombolysis in Myocardial Infarction (TIMI) flow grade, corrected TIMI frame count, myocardial blush grade, or MACE.

Optimization of Percutaneous Coronary Intervention Using Optical Coherence Tomography

Compared to the luminogram obtained by angiography, intravascular modalities produce cross-sectional images of coronary arteries with a far greater spatial resolution. It is capable of accurately determining the vessel size and plaque morphology. It also eliminates some disadvantages such as contrast streaming, foreshortening, vessel overlap, and angle dependency inherent to angiography. Currently, the development of its system and the visualization of coronary arteries has shown significant advancement. Of those, optical coherence tomography (OCT) makes it possible to obtain high-resolution images of intraluminal and transmural coronary structures leading to navigation of the treatment strategy before and after stent implantations. The aim of this review is to summarize the published data on the clinical utility of OCT, focusing on the use of OCT in interventional cardiology practice to optimize percutaneous coronary intervention.

Everolimus- vs. novolimus-eluting bioresorbable scaffolds in patients with acute coronary syndrome

BACKGROUND

Limited data exist on bioresorbable scaffolds (BRS) in patients with acute coronary syndrome (ACS). The aim of the present study was to evaluate novolimus-eluting BRS (DESolve) as interventional treatment for patients with ACS, and to compare its 12-month outcomes with the everolimus-eluting bioresorbable scaffolds (Absorb).

METHODS

In this retrospective study, patients with ACS (including unstable angina pectoris, ST-segment elevation myocardial infarction, or non-ST-segment elevation myocardial infarction) treated with either the Absorb or the DESolve BRS were evaluated in a 1:1 matched-pair analysis. Major adverse cardiac events (MACE), including death, myocardial infarction, and target lesion revascularization, were evaluated as a major endpoint. The occurrence of scaffold thrombosis was also assessed.

RESULTS

A total of 102 patients were eligible for this analysis. The rate of MACE at 12 months was comparable between the Absorb and the DESolve group (8.3% vs. 6.8%, p = 0.738). The occurrence of target lesion revascularization (6.2% vs. 4.7%; p = 0.700) and scaffold thrombosis (4.1% vs. 2.1%; p = 0.580) was comparable as well. All instances of scaffold thrombosis occurred within 30 days of the index procedure.

CONCLUSION

In this study, similar 12-month event rates were observed for both BRS types after implantation for the treatment of ACS.

Intracoronary Optical Coherence Tomography 2018: Current Status and Future Directions

The advent of intravascular imaging has been a significant advancement in visualization of coronary arteries, particularly with optical coherence tomography (OCT) that allows for high-resolution imaging of intraluminal and transmural coronary structures. Accumulating data support a clinical role for OCT in a multitude of clinical scenarios, including assessing the natural history of atherosclerosis and modulating effects of therapies, mechanisms of acute coronary syndromes, mechanistic insights into the effects of novel interventional devices, and optimization of percutaneous coronary intervention. In this state-of-the-art review, we provide an overview of the published data on the clinical utility of OCT, highlighting the areas that need further investigation and the current barriers for further adoption of OCT in interventional cardiology practice.

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.

Novel bifurcation stents coated with bioabsorbable nanofibers with extended and controlled release of rosuvastatin and paclitaxel

A novel bifurcation stent coated with bioabsorbable nanofibers that deliver the extended and controlled release of rosuvastatin and paclitaxel was developed. Bioabsorbable bifurcation stents, consisting of a double-slit tubular main body and two spiral branches, were manufactured. Bi-layered poly (lactic-co-glycolic acid) nanofibers that contained rosuvastatin and paclitaxel were used for treating the stents. Various properties of the fabricated stents, including compression strengths, collapse pressure, water contact angle and flow properties within a circulation model, were quantified. In vitro nanofibrous elution chromatography assays from the drug-loading bifurcation stents were carried out for the release patterns of pharmaceuticals. The effectiveness of eluted rosuvastatin and paclitaxel in inhibiting the adhesion of platelets as well as the proliferation of smooth muscle cells (SMCs) were studied, respectively. The experimental results suggest that bioabsorbable nanofibrous bifurcation stents released high concentrations of rosuvastatin and paclitaxel for 27 and 70 days, respectively. The eluted drugs of rosuvastatin and paclitaxel effectively reduced adherent platelets and the proliferation of SMCs. The developed bioabsorbable nanofibrous bifurcation stents herein may provide a promising means of treating cardiovascular bifurcation lesions.

Effect of Adjunct Balloon Dilation after Long Everolimus-eluting Stent Deployment on Major Adverse Cardiac Events

Background and Objectives

The effectiveness of adjunct balloon dilation after drug-eluting stent (DES) deployment has not been sufficiently evaluated. We evaluated whether adjunct balloon dilation was associated with a reduction in major adverse cardiac events (MACEs) after long everolimus-eluting stents (EESs) implantation.

Subjects and Methods

Drawing from 2 randomized trials, a total of 1,672 patients treated with long EES were analyzed. Of 1,672 patients, 1,061 patients (64%) received post-stent adjunct balloon dilation. MACE, defined as a composite of cardiac death, myocardial infarction, and target-lesion revascularization (TLR), was compared between patients who received post-stent adjunct balloon dilation and patients who did not in 595 propensity score-matched pairs.

Results

For the matched population, MACE occurred in 29 patients (4.9%) who received adjunct balloon dilation and in 29 patients (4.9%) who did not (hazard ratio [HR], 1.01; 95% confidence interval [CI], 0.60–1.69; p=0.972). However, significant interactions were observed among the subgroups for clinical presentation and vessel size. Adjunct balloon dilation was more favored within the subset of patients with stable angina vs. the subset of patients with acute coronary syndrome (p for interaction=0.037), and within the subset of lesions with small vessel diameter (reference vessel diameter [RVD] <3 mm) vs. the subset of lesions with larger vessel diameter (RVD ≥3 mm; p for interaction=0.027).

Conclusion

Adjunct balloon dilation was not associated with MACE reduction at 1 year among patients requiring long EES implantation. However, post-stent adjunct balloon dilation may be necessary for patients requiring long EES implantation who present with stable angina or for lesions with small vessel diameters.

Long-term clinical results of bioresorbable absorb scaffolds using the PSP-technique in patients with and without diabetes

OBJECTIVES

We evaluated clinical results up to 36 months after implantation of Absorb BVS using PSP-technique and compared the outcome of patients with and without diabetes mellitus.

BACKGROUND

Absorb II demonstrated that interventional treatment of coronary artery disease with bioresorbable vascular scaffolds (BVS) without proper PSP-technique (pre-dilation, proper sizing, and post-dilation) is associated with an increased thrombotic risk, even in simple lesions.

METHODS

In this prospective study 319 patients with 420 lesions were enrolled and treated with the Absorb BVS. Pre-dilation was mandatory and post-dilation with a high-pressure balloon was performed in patients with a scaffold length >12 mm. Patients were clinically followed up to 3 years. Primary outcome measure was the device-oriented endpoint (DoCE) defined as cardiac death, myocardial infarction not clearly related to a non-target vessel and target lesion revascularization.

RESULTS

DoCE was 5.0%, 7.1%, and 10.0% after 12, 24, and 36 months for the total population. Rate of scaffold thrombosis was 0.5%, 0.8%, and 1.4% after 12, 24, and 36 months. Rate of DoCE was higher in the diabetic subgroup with 9.1%, 12.6%, and 12.9% after 12, 24, and 36 months compared with 4.0% (P = 0.13), 5.6% (P = 0.05), and 9.9% (P = 0.20) in patients without diabetes mellitus.

CONCLUSIONS

Patients treated with the Absorb BVS using the PSP-technique show good results up to 3 years with a low rate of scaffold thrombosis. Patients suffering from diabetes mellitus have an increased rate of DoCE compared with non-diabetic patients.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov_NCT02162056.

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

Final stent dimensions remain an important predictor of restenosis, target vessel revascularisation (TVR) and subacute stent thrombosis (ST), even in the drug-eluting stent (DES) era. Stent balloons are usually semi-compliant and thus even high-pressure inflation may not achieve uniform or optimal stent expansion. Post-dilatation with non-compliant (NC) balloons after stent deployment has been shown to enhance stent expansion and could reduce TVR and ST. Based on supporting evidence and in the absence of large prospective randomised outcome-based trials, post-dilatation with an NC balloon to achieve optimal stent expansion and maximal luminal area is a logical technical recommendation, particularly in complex lesion subsets.

Coronary artery stents: advances in technology

The introduction of percutaneous coronary intervention (PCI) in the late 1970s revolutionized the management of stable and unstable coronary artery disease, providing an effective, quick, safe, and increasingly widely available method for coronary revascularization for many patients. Rapid development in this field led to the introduction of a number of new technologies, including intracoronary stents that have resulted in improved efficacy and long-term safety. In this manuscript we review the experience with the 2 major available classes of stents (bare metal [BMS], drug-eluting [DES]) and describe the delivery systems for these stents. An evidence review of the large trial data comparing balloon angioplasty, BMS, and DES demonstrates the incremental advances over time, with the latest generation of DES achieving the lowest rates of restenosis, stent thrombosis, and recurrent myocardial infarction. In addition, we provide an overview of the latest developments in stent technology, including the introduction of bioresorbable stents and new stent delivery systems. These latest advances are hoped to further improve outcomes while reducing costs due to a reduction in the need for future procedures and hospitalizations due to recurrent coronary disease.

Efficacy of non-compliant balloon post-dilation in optimization of contemporary stents: A digital stent enhancement study

Background

There is no evidence from randomized trials for the benefit of routine non-compliant balloon (NCB) post-dilation after stent deployment. Despite being the gold standard, intravascular ultrasound is infrequently performed due to time and cost constraints and a suitable alternative technology is required for routine assessment of stent expansion. The purpose of this study was to assess the contribution of NCB post-dilation in optimizing contemporary stents by using digital stent enhancement (DSE).

Methods

We treated 120 patients with stent insertion and assessed the stents with DSE before and after NCB use. Optimal expansion was defined as the minimum stent diameter (MSD) ≥ 90% of the nominal stent diameter, an adaptation of the MUSIC and POSTIT trial criteria. Stent deployment was performed at 12 atm pressure followed by routine NCB post-dilation at ≥ 14 atm.

Results

The mean reference diameter on QCA was 2.75 mm (SD 0.63) and mean stent diameter was 3.15 mm (SD 0.46). At a mean stent deployment pressure of 11.7 atm (SD 2.4), only 21% of stents were optimally expanded. After NCB inflation at a mean of 16.9 atm (SD 2.8), MSD increased by 0.26 mm (SD 0.24), optimal stent expansion increased from 21% to 58% and mean stent symmetry ratio increased from 0.83 to 0.87 (p < 0.0001).

Conclusions

Contemporary stents are sub-optimally expanded in the majority of cases after standard deployment compared with nominal sizes. Adjunctive NCB post-dilation optimized an additional 37% of stents. DSE analysis can assist in qualitative and quantitative stent assessments and can potentially facilitate a selective NCB post-dilation strategy to achieve optimal stent expansion.

Changes of plasma B-type natriuretic peptide levels after high-pressure post-dilation following coronary stent deployment

OBJECTIVE

To evaluate the changes of plasma B-type natriuretic peptide(BNP) levels after high-pressure post-dilation following coronary stent deployment.

METHODS

A total of 173 patients undergoing percutaneous coronary intervention for the left anterior descending artery were enrolled into the study. All patients were divided into two groups: the conventional group and the post-dilation group. The plasma BNP, troponin I(TnI), myocardial band isoenzyme of creatine kinase(CK-MB) levels and the serum high sensitive C-reactive protein(hs-CRP) levels immediately before and 24 hours after the interventional procedures were compared between the two groups.

RESULTS

There were no significant differences between the two groups in terms of clinical features, clinical and biochemical parameters, stent parameters, pre-procedural plasma BNP and TnI levels, pre-procedural serum hs-CRP levels, as well as pre- and post-procedural CK-MB levels (all P>0.05). In the conventional group, post-procedural plasma BNP levels were significantly reduced when compared with the pre-procedural levels, median(25th,75th) were 32.5 ng/L(15.0,52.4) vs. 37.7 ng/L(18.2,67.3), P = 0.001. In the post-dilation group, post-procedural plasma BNP levels were significantly increased when compared with the pre-procedural levels, median(25th,75th) were 53.5 ng/L(29.6,82.8) vs. 44.2 ng/L(17.15,70.7), P<0.0001. Post-procedural plasma TnI levels were also significantly increased when compared with the pre-procedural levels in both groups, median(25th,75th) were 0.02 ng/L(0.01,0.08) vs. 0.01 ng/L(0.01,0.01), 0.05 ng/L(0.01,0.35) vs. 0.01 ng/L(0.01,0.01), respectively, P<0.0001, so were the serum hs-CRP levels, median(25th,75th) were 3.3 mg/L(2.4,4.7) vs. 2.2 mg/L(1.4,3.3), 4.2 mg/L(3.175,5.825) vs. 2.3 mg/L(1.45,3.6), respectively, P<0.0001. Post-procedural plasma BNP, TnI and serum hs-CRP levels in the post-dilation group were significantly higher than those in the conventional group(all P<0.0001).

CONCLUSION

High-pressure post-dilation following coronary stent deployment resulted in a significant increase of plasma BNP levels, as well as plasma TnI levels and serum hs-CRP levels, which may be related to myocardial perfusion, more myocardial injury and more inflammation.

Maximal expansion capacity with current DES platforms: a critical factor for stent selection in the treatment of left main bifurcations?

AIMS

Left main stenting is increasingly performed and often involves deployment of a single stent across vessels with marked disparity in diameters. Knowing stent expansion capacity is critical to ensure adequate strut apposition after post-dilatation of the stent has been performed. Coronary stents are usually manufactured in only two or three different model designs with each design having a different maximal expansion capacity. Information about the different workhorse designs and their maximal achievable diameter is not commonly provided by manufacturers but, in the absence of this critically important information, stents implanted in segments with major changes in vessel diameter have the potential to become grossly overstretched and to remain incompletely apposed.

METHODS AND RESULTS

We examined the differences in workhorse designs of six commercially available drug-eluting stents (DES): the PROMUS Element, Taxus Liberté, XIENCE Prime, Resolute Integrity, BioMatrix Flex and Cypher Select stents. Using micro-computed tomography, we tested oversizing capabilities above nominal pressures for the different workhorse designs of the six DES using 4.0, 5.0 and 6.0 mm post-dilatation balloons inflated to 14 atmospheres. MLD could be increased significantly in all stents, only restricted by workhorse design limitations. Minimal inner lumen diameter (MLD) achieved after two successive 6.0 mm post-dilatations of the largest design (4.0 mm stent) was 5.7 mm for the Element, 5.6 mm for the XIENCE Prime, 6.0 mm for the Taxus, 5.4 mm for the Resolute Integrity, 5.9 mm for the BioMatrix and 5.8 mm for the Cypher stent. Significant deformations were observed during stent oversizing with large changes in terms of cell opening and crowns expansion. These are affected by design structure and reveal important differences among all stents tested. Such extensive deformations may alter the functional ability of an individual stent to scaffold a lesion and prevent restenosis.

CONCLUSIONS

Stent selection based on stent model design may be critical, particularly for treatment of large artery and left main bifurcations where overexpansion is normally required to optimise results and ensure full expansion of the stent.

Effect of stent inflation pressure and post-dilatation on the outcome of coronary artery intervention. A report of more than 90,000 stent implantations

Background

Percutaneous coronary intervention (PCI) stent inflation pressure correlates to angiographic lumen improvement and stent expansion but the relation to outcome is not clarified. Using comprehensive registry data our aim was to evaluate how stent inflation pressure influences restenosis, stent thrombosis and death following PCI.

Methods

We evaluated all consecutive coronary stent implantations in Sweden during 46 months from 2008 using data from the Swedish Coronary Angiography and Angioplasty Registry (SCAAR). We used logistic regression and Cox proportional hazard modeling to estimate risk of outcomes with different balloon pressures.

Results

In total, 93 697 stents were eligible for analysis and divided into five different pressure interval groups: ≤15 atm, 16–17 atm, 18–19 atm, 20–21 atm and ≥22 atm. The risks of stent thrombosis and restenosis were significantly higher in the ≤15 atm, 18–19 atm and ≥22 atm groups (but not in the 16–17 atm group) compared to the 20–21 atm group. There were no differences in mortality. Post-dilatation was associated with a higher restenosis risk ratio (RR) of 1.22 (95% confidence interval (CI) 1.14–1.32, P<0.001) but stent thrombosis did not differ statistically between procedures with or without post-dilatation. The risk of death was lower following post-dilatation (RR 0.81 (CI 0.71–0.93) P = 0.003) and the difference compared to no post-dilatation was seen immediately after PCI.

Conclusion

Our retrospective study of stent inflation pressure identified a possible biological pattern—the risks of stent thrombosis and of restenosis appeared to be higher with low and very high pressures. Post-dilatation might increase restenosis risk.

Performance of Self-Expanding Nitinol Stent in a Curved Artery: Impact of Stent Length and Deployment Orientation

The primary aim of this work was to investigate the performance of self-expanding Nitinol stents in a curved artery through finite element analysis. The interaction between a PROTÉGÉTM GPSTM self-expanding Nitinol stent and a stenosed artery, as well as a sheath, was characterized in terms of acute lumen gain, stent underexpansion, incomplete stent apposition, and tissue prolapse. The clinical implications of these parameters were discussed. The impact of stent deployment orientation and the stent length on the arterial wall stress distribution were evaluated. It was found that the maximum principal stress increased by 17.46%, when the deployment orientation of stent was varied at a 5 deg angle. A longer stent led to an increased contact pressure between stent and underlying tissue, which might alleviate the stent migration. However, it also caused a severe hinge effect and arterial stress concentration correspondingly, which might aggravate neointimal hyperplasia. The fundamental understanding of the behavior of a self-expanding stent and its clinical implications will facilitate a better device design.

Enhanced stent imaging improves the diagnosis of stent underexpansion and optimizes stent deployment

OBJECTIVES

To investigate the clinical value and diagnostic accuracy of enhanced stent imaging (ESI) as compared with quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS).

BACKGROUND

ESI is an image acquisition and processing angiography-based software that improves visualization and provides measurements of deployed stents.

METHODS

A total of 40 consecutive patients (42 stents) were studied. Stent deployment was evaluated sequentially and independently by angiography, ESI, and IVUS. Following each imaging modality, the operator determined the necessity of postdilation unrelated to the other modalities. Stent diameters were measured off-line by QCA, ESI, and IVUS at several sites along the deployed stent and compared.

RESULTS

Following stent deployment and based solely on angiography, the operator decided to postdilate seven of the 42 stents (16.7%). This decision was not changed after reviewing the ESI images of these seven stents. Of the 35 stents not requiring postdilation based on angiography alone, ESI influenced the operator to change the decision and postdilate 10 of 35 stents (28.6%). The ESI-based measurements had better correlation with IVUS (r = 0.721, P < 0.0001) than did QCA with IVUS (r = 0.563, P < 0.0001). Bland-Altman analysis showed a trend towards better agreement between ESI and IVUS than between QCA and IVUS (mean differences = 0.038 vs. 0.121; P = 0.19, respectively).

CONCLUSIONS

ESI is an easy to use modality that enhances stent visualization, helps in the decision making process whether to postdilate the stent, and provides estimation of stent expansion with better correlations than QCA when compared to IVUS. © 2012 Wiley Periodicals, Inc.

A randomized controlled trial in second-generation zotarolimus-eluting Resolute stents versus everolimus-eluting Xience V stents in real-world patients: the TWENTE trial

OBJECTIVES

The aim of this study was to compare the safety and efficacy of Resolute zotarolimus-eluting stents (ZES) (Medtronic Cardiovascular, Santa Rosa, California) with Xience V everolimus-eluting stents (EES) (Abbott Vascular Devices, Santa Clara, California) at 1-year follow-up.

BACKGROUND

Only 1 randomized trial previously compared these stents.

METHODS

This investigator-initiated, patient-blinded, randomized noninferiority study had limited exclusion criteria (acute ST-segment elevation myocardial infarctions not eligible). Patients (n = 1,391; 81.4% of eligible population) were randomly assigned to ZES (n = 697) or EES (n = 694). Liberal use of stent post-dilation was encouraged. Cardiac biomarkers were systematically assessed. The primary endpoint was target vessel failure (TVF), a composite of cardiac death, myocardial infarction not clearly attributable to non-target vessels, and clinically indicated target-vessel revascularization. An external independent research organization performed clinical event adjudication (100% follow-up data available). Analysis was by intention-to-treat.

RESULTS

Acute coronary syndromes were present in 52% and "off-label" feature in 77% of patients. Of the lesions, 70% were type B2/C; the post-dilation rate was very high (82%). In ZES and EES, TVF occurred in 8.2% and 8.1%, respectively (absolute risk-difference 0.1%; 95% confidence interval: -2.8% to 3.0%, p(noninferiority) = 0.001). There was no significant between-group difference in TVF components. The definite-or-probable stent thrombosis rates were relatively low and similar for ZES and EES (0.9% and 1.2%, respectively, p = 0.59). Definite stent thrombosis rates were also low (0.58% and 0%, respectively, p = 0.12). In EES, probable stent thrombosis beyond day 8 was observed only in patients not adhering to dual antiplatelet therapy.

CONCLUSIONS

Resolute ZES were noninferior to Xience V EES in treating "real-world" patients with a vast majority of complex lesions and "off-label" indications for drug-eluting stents, which were implanted with liberal use of post-dilation. (The Real-World Endeavor Resolute Versus XIENCE V Drug-Eluting SteNt Study: Head-to-head Comparison of Clinical Outcome After Implantation of Second Generation Drug-eluting Stents in a Real World Scenario; NCT01066650).