Stent Expansion Indexes to Predict Clinical Outcomes: An IVUS Substudy From ADAPT-DES

Intravascular imaging in the diagnosis and management of patients with suspected intracoronary pathologies: A CJC White Paper

Intravascular imaging has become an integral part of the diagnostic and management strategies for intracoronary pathologies. This White Paper summarizes current evidence and its implications on the use of intravascular imaging in interventional cardiology practice. The areas addressed are planning and optimization of percutaneous coronary intervention, management of stent failure, and evaluation of ambiguous coronary lesions and myocardial infarction with non-obstructive coronary disease (MINOCA). Findings are presented following the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system in an expert consensus process involving a diverse Writing group and vetted by a Review group. Expert consensus was achieved around nine statements. Use of intravascular imaging in guiding percutaneous revascularization is supported by high quality evidence, particularly for lesions with increased risk of recurrent events or stent failure. Specific considerations for intravascular imaging guidance of intervention in left main lesions, chronic occlusion lesions as well as patients at high risk of contrast nephropathy are explored. Use of intravascular imaging to identify pathologies associated with stent failure and guide repeat intervention, resolve ambiguities in lesion assessment and establish diagnoses in patients presenting with MINOCA is supported by moderate to low quality evidence. Each topic is accompanied by clinical pointers to aid the practicing interventional cardiologist in implementation of the White paper findings. The findings of this White Paper will help to guide the utilization of intravascular imaging towards those situations in which the balance of efficacy, safety and cost are most optimal.

Optimal Intravascular Ultrasound-Guided Percutaneous Coronary Intervention in Patients With Multivessel Disease and Diabetes

There is a scarcity of data on clinical outcomes after intravascular ultrasound (IVUS)-guided percutaneous coronary intervention (PCI) in patients with multivessel disease and diabetes. The Optimal Intravascular Ultrasound Guided Complex Percutaneous Coronary Intervention study multivessel cohort was a prospective, multicenter, single-arm trial enrolling 1,021 patients who underwent multivessel PCI, including left anterior descending coronary artery using IVUS, aiming to meet the prespecified OPTIVUS criteria for optimal stent expansion. We compared the clinical outcomes between those patients with and without diabetes. The primary end point was a composite of death, myocardial infarction, stroke, or any coronary revascularization. There were 560 patients (54.8%) with diabetes and 461 patients (45.2%) without diabetes. The mean age was not different between the 2 groups (70.9 ± 9.7 vs 71.7 ± 10.4 years, p = 0.17). Patients with diabetes more often had chronic kidney disease and complex coronary artery disease, as indicated by the greater total number of stents and longer total stent length. The rate of meeting the OPTIVUS criteria was not different between the 2 groups (61.2% vs 60.7%, p = 0.83). The cumulative 1-year incidence of the primary end point was not different between the 2 groups (10.8% vs 9.8%, log-rank p = 0.65). After adjusting for confounders, the risk of diabetes relative to nondiabetes remained insignificant for the primary end point (hazard ratio 0.97, 95% confidence interval 0.65 to 1.44, p = 0.88). In conclusion, in patients who underwent multivessel IVUS-guided PCI and were managed with contemporary clinical practice, patients with diabetes had similar 1-year outcomes to patients without diabetes.

Intravascular Imaging Findings After PCI in Patients With Focal and Diffuse Coronary Artery Disease

BACKGROUND

Following percutaneous coronary intervention (PCI), optical coherence tomography provides prognosis information. The pullback pressure gradient is a novel index that discriminates focal from diffuse coronary artery disease based on fractional flow reserve pullbacks. We sought to investigate the association between coronary artery disease patterns, defined by coronary physiology, and optical coherence tomography after stent implantation in stable patients undergoing PCI.

METHODS AND RESULTS

This multicenter, prospective, single-arm study was conducted in 5 countries (NCT03782688). Subjects underwent motorized fractional flow reserve pullbacks evaluation followed by optical coherence tomography-guided PCI. Post-PCI optical coherence tomography minimum stent area, stent expansion, and the presence of suboptimal findings such as incomplete stent apposition, stent edge dissection, and irregular tissue protrusion were compared between patients with focal versus diffuse disease. Overall, 102 patients (105 vessels) were included. Fractional flow reserve before PCI was 0.65±0.14, pullback pressure gradient was 0.66±0.14, and post-PCI fractional flow reserve was 0.88±0.06. The mean minimum stent area was 5.69±1.99 mm2 and was significantly larger in vessels with focal disease (6.18±2.12 mm2 versus 5.19±1.72 mm2, P=0.01). After PCI, incomplete stent apposition, stent edge dissection, and irregular tissue protrusion were observed in 27.6%, 10.5%, and 51.4% of the cases, respectively. Vessels with focal disease at baseline had a lower prevalence of incomplete stent apposition (11.3% versus 44.2%, P=0.002) and more irregular tissue protrusion (69.8% versus 32.7%, P<0.001).

CONCLUSIONS

Baseline coronary pathophysiological patterns are associated with suboptimal imaging findings after PCI. Patients with focal disease had larger minimum stent area and a higher incidence of tissue protrusion, whereas stent malapposition was more frequent in patients with diffuse disease.

Rotational atherectomy combined with cutting balloon to optimise stent expansion in calcified lesions: the ROTA-CUT randomised trial

BACKGROUND

Percutaneous coronary intervention (PCI) of calcified lesions remains challenging for interventionalists.

AIMS

We aimed to investigate whether combining rotational atherectomy (RA) with cutting balloon angioplasty (RA+CBA) results in more optimal stent expansion compared with RA followed by non-compliant balloon angioplasty (RA+NCBA).

METHODS

ROTA-CUT is a prospective, multicentre, randomised trial of 60 patients with coronary artery disease undergoing PCI of moderately or severely calcified lesions with drug-eluting stent implantation. Patients were randomised 1:1 to either RA+CBA or RA+NCBA. The primary endpoint was the minimum stent area on intravascular ultrasound (IVUS). Secondary endpoints included minimum lumen area and stent expansion assessed by IVUS and acute lumen gain, final residual diameter stenosis and minimum lumen diameter assessed by angiography. Clinical endpoints were obtained at 30 days.

RESULTS

The mean age was 71.1±9.4 years, and 22% were women. The procedural details of RA were similar between groups, as were procedure duration and contrast use. Minimum stent area was similar with RA+CBA versus RA+NCBA (6.7±1.7 mm2 vs 6.9±1.8 mm2; p=0.685). Furthermore, there were no significant differences regarding the other IVUS and angiographic endpoints. Procedural complications were rare, and 30-day clinical events included 2 myocardial infarctions and 1 target vessel revascularisation in the RA+CBA group and 1 myocardial infarction in the RA+NCBA group.

CONCLUSIONS

Combining RA with CBA resulted in a similar minimum stent area compared with RA followed by NCBA in patients undergoing PCI of moderately or severely calcified lesions. RA followed by CBA was safe with rare procedural complications and few clinical adverse events at 30 days.

Optimal Minimal Stent Area and Impact of Stent Underexpansion in Left Main Up-Front 2-Stent Strategy

BACKGROUND

We previously reported the use of minimal stent area to predict angiographic in-stent restenosis after drug-eluting stent implantation for unprotected left main (LM) disease. We aimed to evaluate the optimal minimal stent area criteria for up-front LM 2-stenting based on long-term clinical outcomes.

METHODS

We identified 292 consecutive patients with LM bifurcation stenosis who were treated using the crush technique. The final minimal stent area was measured in the ostial left anterior descending artery (LAD), ostial left circumflex artery (LCX), and distal LM. The primary outcome was 5-year major adverse cardiac events, including all-cause death, myocardial infarction, and target lesion revascularization.

RESULTS

The minimal stent area cutoff values that best predicted the 5-year major adverse cardiac events were 11.8 mm2 for distal LM (area under the curve, 0.57; P=0.15), 8.3 mm2 for LAD ostium (area under the curve, 0.62; P=0.02), and 5.7 mm2 for LCX ostium (area under the curve, 0.64; P=0.01). Using these criteria, the risk of 5-year major adverse cardiac events was significantly associated with stent underexpansion in the LAD ostium (hazard ratio, 3.14; [95% CI, 1.23-8.06]; P=0.02) and LCX ostium (hazard ratio, 2.60 [95% CI, 1.11-6.07]; P=0.03) but not in the distal LM (hazard ratio, 0.81 [95% CI, 0.34-1.91]; P=0.63). Patients with stent underexpansion in both ostial LAD and LCX had a significantly higher rate of 5-year major adverse cardiac events than those with no or 1 underexpanded stent of either ostium (P<0.01).

CONCLUSIONS

Stent underexpansion in the LAD and LCX ostium was significantly associated with long-term outcomes in patients who underwent up-front 2-stenting for LM bifurcation stenosis.

Deteriorative Effect of a Combination of Hypertriglyceridemia and Low High-Density Lipoprotein Cholesterolemia on Target Lesion Revascularization after Everolimus-Eluting Stent Implantation

AIM

This study aimed to investigate the association between a combination of elevated triglyceride (TG) and reduced high-density lipoprotein cholesterol (HDL-C) levels and target lesion revascularization (TLR) following everolimus-eluting stent (EES) implantation. The adverse impact of clinical, lesion, and procedural characteristics on TLR in patients with elevated TG and reduced HDL-C levels was also assessed.

METHODS

We retrospectively collected data on 3,014 lesions from 2,022 consecutive patients, who underwent EES implantation at Koto Memorial Hospital. Atherogenic dyslipidemia (AD) is defined as a combination of non-fasting serum TG ≥ 175 mg/dL and HDL-C ＜40 mg/dL.

RESULTS

AD was observed in 212 lesions in 139 (6.9%) patients. The cumulative incidence of clinically driven TLR was significantly higher in patients with AD than in those without AD (hazard ratio [HR] 2.31, 95% confidence interval [CI] 1.43-3.73, P=0.0006). Subgroup analysis showed that AD increased the risk of TLR with the implantation of small stents (≤ 2.75 mm). Multivariable Cox regression analysis showed that AD was an independent predictor of TLR in the small EES stratum (adjusted HR 3.00, 95% CI 1.53-5.93, P=0.004), whereas the incidence of TLR was similar in the non-small-EES stratum, irrespective of the presence or absence of AD.

CONCLUSIONS

Patients with AD had a higher risk of TLR after EES implantation, and this risk was greater for lesions treated with small stents.

Modified balloons to prepare severely calcified coronary lesions before stent implantation: a systematic review and meta-analysis of randomized trials

BACKGROUND

The performance of modified balloons (namely cutting or scoring balloons) to prepare severely calcified lesions in patients undergoing percutaneous coronary intervention (PCI) remains controversial. We investigated the clinical and imaging outcomes of patients undergoing PCI assigned to modified balloon therapy to prepare severely calcified coronary lesions before stent implantation.

METHODS

In this meta-analysis, we aggregated the study-level data from trials enrolling invasively treated patients who were randomly assigned to modified balloon or control therapy to prepare severely calcified lesions before stenting. The primary outcome was major adverse cardiac events (MACE), including death, myocardial infarction (MI), and repeat revascularization. The secondary outcomes included the individual components of the primary outcome, coronary perforation and final minimal stent area (MSA) as measured by intracoronary imaging.

RESULTS

A total of 648 participants in six trials were allocated to modified balloon therapy (n = 335) or control therapy (semi-compliant, non-compliant, or super high-pressure balloon, n = 313). The median follow-up was 11 months. Overall, MACE occurred in 8.96% of patients assigned to a modified balloon and 12.78% of patients assigned to control therapy [risk ratio = 0.70, 95% confidence interval (CI) 0.35-1.39; P = 0.24]. There was a significant treatment effect-by-modified balloon type interaction for the outcome MACE in patients assigned to cutting balloon compared with control therapy [RR = 0.40 (0.28-0.56), P for interaction (Pint) < 0.001]. Patients treated with a modified balloon compared with control therapy showed neither a significant difference for the other clinical outcomes nor for final MSA [standardized mean difference = 0.67 (- 0.71, 2.06); P = 0.26].

CONCLUSIONS

In patients treated with PCI for severely calcific coronary artery disease a strategy of lesion preparation with a modified balloon before stenting does not improve clinical or imaging outcomes compared with control therapy. The different performance of cutting and scoring balloons warrants further investigation.

Management strategies for heavily calcified coronary stenoses: an EAPCI clinical consensus statement in collaboration with the EURO4C-PCR group

Since the publication of the 2015 EAPCI consensus on rotational atherectomy, the number of percutaneous coronary interventions (PCI) performed in patients with severely calcified coronary artery disease has grown substantially. This has been prompted on one side by the clinical demand for the continuous increase in life expectancy, the sustained expansion of the primary PCI networks worldwide, and the routine performance of revascularization procedures in elderly patients; on the other side, the availability of new and dedicated technologies such as orbital atherectomy and intravascular lithotripsy, as well as the optimization of the rotational atherectomy system, has increased operators' confidence in attempting more challenging PCI. This current EAPCI clinical consensus statement prepared in collaboration with the EURO4C-PCR group describes the comprehensive management of patients with heavily calcified coronary stenoses, starting with how to use non-invasive and invasive imaging to assess calcium burden and inform procedural planning. Objective and practical guidance is provided on the selection of the optimal interventional tool and technique based on the specific calcium morphology and anatomic location. Finally, the specific clinical implications of treating these patients are considered, including the prevention and management of complications and the importance of adequate training and education.

Impact of Stent Expansion Index on Stent Failure After Left Main Stenting

Impact of the stent expansion index (EXPI) in percutaneous coronary intervention (PCI) for unprotected left main distal bifurcation lesions (ULMD) has been not completely understood especially in current-generation drug-eluting stent (cDES) era. We evaluated the impact of EXPI on clinical outcomes after PCI with cDES for ULMD. We identified 342 patients treated with cDES for ULMD and postintervention intravascular ultrasound between January 2010 and December 2019. In this study, the ratio of minimum stent area (MSA) to reference vessel area at the MSA site was adopted to assess the stent expansion. We defined the patients with the first and second tertile as low-intermediate EXPI group and those with the third tertile as high EXPI group and compared the clinical outcomes between both groups. The primary end point was target lesion failure (TLF). TLF was defined as a composite of cardiac death, target lesion revascularization (TLR) ,and myocardial infarction. The MSA was located in the ostium of left anterior descending coronary artery in most cases (318 of 342 patients; 93.0%). There were no significant differences between both groups in the baseline clinical, lesion, and procedural characteristics. The high EXPI group had lower TLF rate than the low-intermediate EXPI group (10.2% vs 19.9%, log-rank p = 0.033). In conclusion, this is the first report that the higher ratio of MSA to reference vessel area at the MSA site, which was defined as stent EXPI, was associated with more favorable clinical outcomes after PCI for ULMD.

Evaluation of a Rabbit Model of Vascular Stent Healing: Application of Optical Coherence Tomography

Percutaneous coronary intervention (PCI) is a management strategy for symptomatic obstructive coronary artery disease (CAD). Despite advancements, in-stent restenosis (ISR) still imparts a 1-2% annual rate of repeat revascularization-a focus of ongoing translational research. Optical coherence tomography (OCT) provides high resolution virtual histology of stents. Our study evaluates the use of OCT for virtual histological assessment of stent healing in a rabbit aorta model, enabling complete assessment of intraluminal healing throughout the stent. ISR varies based on intra-stent location, stent length, and stent type in a rabbit model-important considerations for translational experimental design. Atherosclerosis leads to more prominent ISR proliferation independent of stent-related factors. The rabbit stent model mirrors clinical observations, while OCT-based virtual histology demonstrates utility for pre-clinical stent assessment. Pre-clinical models should incorporate clinical and stent factors as feasible to maximize translation to clinical practice.

Impact of Calcium Eccentricity on the Safety and Effectiveness of Coronary Intravascular Lithotripsy: Pooled Analysis From the Disrupt CAD Studies

BACKGROUND

Coronary intravascular lithotripsy (IVL) safely facilitates successful stent implantation in severely calcified lesions. This analysis sought to determine the relative impact of lesion calcium eccentricity on the safety and effectiveness of IVL using high-resolution optical coherence tomography imaging.

METHODS

Individual patient-level data (n=262) were pooled from 4 distinct international prospective studies (Disrupt CAD I, II, III, and IV) and analyzed by an independent optical coherence tomography core laboratory. IVL performance in eccentric versus concentric calcification was analyzed by dividing calcified lesions into quartiles (≤180° [most eccentric], 181°-270°, 271°-359°, and 360° [concentric]) by maximum continuous calcium arc.

RESULTS

In the 230 patients with clear imaging field on optical coherence tomography, there were no differences in preprocedure minimum lumen area, diameter stenosis, or maximum calcium thickness. The calcium length and volume index increased progressively with increasing mean and maximum continuous calcium arc (ie, concentricity). Conversely, the minimum calcium thickness decreased progressively with increasing concentricity. Post-procedure, the number of calcium fractures, fracture depth, and fracture width increased with increasing concentricity, with a 4-fold increase in the number of fractures in lesions with 360° of calcium arc compared with ≤180°. This increase in IVL-induced calcium fracture with increasing calcium burden and concentricity facilitated stent expansion and luminal gain such that there were no significant differences across quartiles.

CONCLUSIONS

IVL induced calcium fractures proportional to the magnitude of coronary artery calcium, including in eccentric calcium, leading to consistent improvements in stent expansion and luminal gain in both eccentric and concentric calcified coronary lesions.

Fractional Flow Reserve-Guided Stent Optimisation in Focal and Diffuse Coronary Artery Disease

Assessing coronary physiology after stent implantation facilitates the optimisation of percutaneous coronary intervention (PCI). Coronary artery disease (CAD) patterns can be characterised by the pullback pressure gradient (PPG) index. The impact of focal vs. diffuse disease on physiology-guided incremental optimisation strategy (PIOS) is unknown. This is a sub-study of the TARGET-FFR randomized clinical trial (NCT03259815). The study protocol directed that optimisation be attempted for patients in the PIOS arm when post-PCI FFR was <0.90. Overall, 114 patients (n = 61 PIOS and 53 controls) with both pre-PCI fractional flow reserve (FFR) pullbacks and post-PCI FFR were included. A PPG ≥ 0.74 defined focal CAD. The PPG correlated significantly with post-PCI FFR (r = 0.43; 95% CI 0.26 to 0.57; p-value < 0.001) and normalised delta FFR (r = 0.49; 95% CI 0.34 to 0.62; p-value < 0.001). PIOS was more frequently applied to vessels with diffuse CAD (6% focal vs. 42% diffuse; p-value = 0.006). In patients randomized to PIOS, those with focal disease achieved higher post-PCI FFR than patients with diffuse CAD (0.93 ± 0.05 vs. 0.83 ± 0.07, p < 0.001). There was a significant interaction between CAD patterns and the randomisation arm for post-PCI FFR (p-value for interaction = 0.004). Physiology-guided stent optimisation was applied more frequently to vessels with diffuse disease; however, patients with focal CAD at baseline achieved higher post-PCI FFR.

Intravascular Ultrasound Guided Intervention in Calcified Coronary Lesions Showed Good Clinical Outcomes during One Year Follow-Up

BACKGROUND

Calcified coronary lesions can cause stent under-expansion, malapposition, and polymer degradation, hence increasing the risk of adverse clinical outcomes. Percutaneous coronary intervention (PCI) guided by intravascular ultrasound (IVUS) has been used regularly to improve outcomes. Our primary aim was to evaluate the clinical efficacy of IVUS-guided PCI in calcified coronary lesions.

METHODS

From August 2018 to December 2021, we prospectively included 300 patients in the CAPIRO study (CAlcified plaque in patients receiving Resolute Onyx^®) at three educational hospitals in Jeonbuk Province. We studied 243 patients (265 lesions) who were followed up for over a year. Based on coronary calcification by IVUS analysis, the patient population was categorized into two groups (Group I: non/mild calcification; Group II: moderate/severe calcification (maximum calcium arc >180° and calcium length > 5 mm)). One-to-one Propensity Score Matching was used to match the baseline characteristics. The stent expansion rate was analyzed by recent criteria. The primary clinical outcome was Major Adverse Cardiac Events (MACE), which included Cardiac death, Myocardial Infarction (MI), and Target Lesion Revascularization (TLR).

RESULTS

After follow-up time, the MACE rate in Group I was 1.99%, comparable to Group II's 1.09% (p = 0.594). The components of MACE did not significantly differ between the two groups. Based on absolute MSA or MSA/MVA at MSA site criteria, the stent expansion rate in Group II was lower than that of Group I. Nevertheless, based on recent relative criteria, the stent expansion rate in both groups was comparable.

CONCLUSIONS

After more than a year of follow-up, IVUS-guided PCI in moderate/severe calcification lesions was associated with good clinical outcomes, which was comparable with non/mild calcification lesions. Future studies with a larger sample size and a more extended follow-up period are required to clarify our findings.

Impact of Eruptive vs Noneruptive Calcified Nodule Morphology on Acute and Long-Term Outcomes After Stenting

BACKGROUND

Whether an eruptive or noneruptive target lesion calcified nodule (CN) portends worse acute and long-term clinical outcomes after stenting has not been established.

OBJECTIVES

The authors sought to compare acute and long-term clinical outcomes in eruptive CN vs noneruptive CN morphology.

METHODS

Using optical coherence tomography, an eruptive CN was defined as an accumulation of small calcium fragments protruding and disrupting the overlying fibrous cap, typically with small amount of thrombus. A noneruptive CN was defined as an accumulation of small calcium fragments with a smooth intact fibrous cap without an overlying thrombus. The primary endpoint was target lesion failure (TLF) including cardiac death, target vessel myocardial infarction, or clinically driven target lesion revascularization in patients with ≥6-month follow-up.

RESULTS

Among 3,231 patients with evaluable pre- and postintervention OCT, 236 patients had lesions with CNs (7.3%). After eliminating 4 secondary lesions and 6 patients without ≥6-month follow-up, 126 (54.8%) lesions with eruptive CNs and 104 (45.2%) lesions with noneruptive CNs formed the current report. Compared with noneruptive CNs, eruptive CNs were independently associated with greater stent expansion (89.2% ± 18.7% vs. 81.5% ± 18.9%; P = 0.003) after adjusting for morphologic and procedural factors. At 2 years, eruptive CNs trended toward more TLF compared with noneruptive CNs (Kaplan-Meier estimates, 19.8% vs 12.5%; P = 0.11) and significantly more target lesion revascularization (18.3% vs 9.6%; P = 0.04). In the adjusted model, eruptive CNs were independently associated with 2-year TLF (HR: 2.07; 95% CI: 1.01-4.50; P = 0.048).

CONCLUSIONS

Compared with noneruptive CN morphology, lesions with an eruptive CN appearance on optical coherence tomography had a worse poststent long-term clinical outcome despite better acute stent expansion.

Target Lesion Revascularization After Intravascular Ultrasound-Guided Percutaneous Coronary Intervention

BACKGROUND

Several stent expansion criteria derived from the intravascular ultrasound (IVUS) evaluation have been proposed to predict future clinical outcomes, but optimal stent expansion criteria as a guide during percutaneous coronary intervention (PCI) are still controversial. There are no studies evaluating the utility of stent expansion criteria along with the clinical and procedural factors in predicting target lesion revascularization (TLR) after contemporary IVUS-guided PCI.

METHODS

OPTIVUS-Complex PCI study (Optimal Intravascular Ultrasound Guided Complex Percutaneous Coronary Intervention) multivessel cohort was a prospective multicenter study enrolling 961 patients undergoing multivessel PCI including left anterior descending coronary artery using IVUS with an intention to meet the prespecified criteria for optimal stent expansion. We compared several stent expansion criteria (minimum stent area [MSA], MSA/distal or average reference lumen area, MSA/distal or average reference vessel area, OPTIVUS criteria, IVUS-XPL [Impact of Intravascular Ultrasound Guidance on Outcomes of Xience Prime Stents in Long Lesions] criteria, ULTIMATE [Intravascular Ultrasound Guided Drug Eluting Stents Implantation in "All-Comers" Coronary Lesions] criteria, and modified MUSIC [Multicenter Ultrasound Stenting in Coronaries Study] criteria) as well as clinical, angiographic, and procedural characteristics between lesions with and without TLR.

RESULTS

Among 1957 lesions, the cumulative 1-year incidence of lesion-based TLR was 1.6% (30 lesions). Hemodialysis, treatment of proximal left anterior descending coronary artery lesions, calcified lesions, small proximal reference lumen area, and small MSA had univariate associations with TLR, while all of the stent expansion criteria except for MSA were not associated with TLR. The independent risk factors of TLR were calcified lesions (hazard ratio, 2.34 [95% CI, 1.03-5.32]; P=0.04) and small proximal reference lumen area (Tertile 1: hazard ratio, 7.01 [95% CI, 1.45-33.93]; P=0.02; and Tertile 2: hazard ratio, 5.40 [95% CI, 1.17-24.90]; P=0.03).

CONCLUSIONS

In contemporary IVUS-guided PCI practice, the 1-year incidence of TLR was very low. MSA, but not other stent expansion criteria, had univariate association with TLR. Independent risk factors of TLR were calcified lesions and small proximal reference lumen area, although the findings should be interpreted with caution due to small number of TLR events, limited lesion complexity, and short duration of follow-up.

Optimal Intravascular Ultrasound-Guided Percutaneous Coronary Intervention in Patients With Multivessel Disease

Background

Intravascular ultrasound (IVUS) was only rarely used in landmark trials comparing percutaneous coronary intervention (PCI) with coronary artery bypass grafting (CABG) in patients with multivessel disease.

Objectives

The authors aimed to evaluate clinical outcomes after optimal IVUS-guided PCI in patients undergoing multivessel PCI.

Methods

The OPTIVUS (OPTimal IntraVascular UltraSound)-Complex PCI study multivessel cohort was a prospective multicenter single-arm study enrolling 1,021 patients undergoing multivessel PCI, including left anterior descending coronary artery using IVUS, aiming to meet the prespecified criteria (OPTIVUS criteria: minimum stent area > distal reference lumen area [stent length ≥28mm], and minimum stent area >0.8 × average reference lumen area [stent length <28mm]) for optimal stent expansion. The primary endpoint was major adverse cardiac and cerebrovascular events (MACCE) (death/myocardial infarction/stroke/any coronary revascularization). The predefined performance goals were derived from the CREDO-Kyoto (Coronary REvascularization Demonstrating Outcome study in Kyoto) PCI/CABG registry cohort-2 fulfilling the inclusion criteria in this study.

Results

In this study, 40.1% of the patients met OPTIVUS criteria in all stented lesions. The cumulative 1-year incidence of the primary endpoint was 10.3% (95% CI: 8.4%-12.2%), which was significantly lower than the predefined PCI performance goal of 27.5% (P < 0.001), and which was numerically lower than the predefined CABG performance goal of 13.8%. The cumulative 1-year incidence of the primary endpoint was not significantly different regardless of meeting or not meeting OPTIVUS criteria.

Conclusions

Contemporary PCI practice conducted in the OPTIVUS-Complex PCI study multivessel cohort was associated with a significantly lower MACCE rate than the predefined PCI performance goal, and with a numerically lower MACCE rate than the predefined CABG performance goal at 1 year.

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.

Stent expansion evaluated by optical coherence tomography and subsequent outcomes

Regarding stent expansion indices, previous optical coherence tomography (OCT) studies have shown minimal stent area (MSA) to be most predictive of adverse events. We sought to evaluate the impact of various stent expansion and apposition indices by post-stent OCT on clinical outcomes and find OCT-defined optimal stent implantation criteria. A total of 1071 patients with 1123 native coronary artery lesions treated with new-generation drug-eluting stents with OCT guidance and final post-stent OCT analysis were included. Several stent expansion indices (MSA, MSA/average reference lumen area, MSA/distal reference lumen area, mean stent expansion, and stent expansion by linear model [stent volume/adaptive reference lumen volume]) were evaluated for their association with device-oriented clinical endpoints (DoCE) including cardiac death, target vessel-related myocardial infarction (MI) or stent thrombosis, and target lesion revascularization. MSA was negatively correlated with the risk of DoCE (hazard ratio [HR] 0.80 [0.68‒0.94]). However, stent expansion by linear model representing the overall volumetric stent expansion was associated with greater risk of DoCE (HR 1.02 [1.00‒1.04]). As categorical criteria, MSA < 5.0 mm² (HR 3.90 [1.99‒7.65]), MSA/distal reference lumen area < 90% (HR 2.16 [1.12‒4.19]), and stent expansion by linear model ≥ 65.0% (HR 1.95 [1.03‒3.89]) were independently associated with DoCE. This OCT study highlights the importance of sufficient stent expansion to achieve adequate, absolute, and relative MSA criteria for improving clinical outcome. It also emphasises that overall volumetric excessive stent expansion may have detrimental effects.

Intravascular Imaging During Percutaneous Coronary Intervention: JACC State-of-the-Art Review

Coronary angiography has historically served as the gold standard for diagnosis of coronary artery disease and guidance of percutaneous coronary intervention (PCI). Adjunctive use of contemporary intravascular imaging (IVI) technologies has emerged as a complement to conventional angiography-to further characterize plaque morphology and optimize the performance of PCI. IVI has utility for preintervention lesion and vessel assessment, periprocedural guidance of lesion preparation and stent deployment, and postintervention assessment of optimal endpoints and exclusion of complications. The role of IVI in reducing major adverse cardiac events in complex lesion subsets is emerging, and further studies evaluating broader use are underway or in development. This paper provides an overview of currently available IVI technologies, reviews data supporting their utilization for PCI guidance and optimization across a variety of lesion subsets, proposes best practices, and advocates for broader use of these technologies as a part of contemporary practice.

Impact of Parathyroid Hormone Level on Intracoronary Calcification and Short- and Long-Term Outcomes in Dialysis Patients Undergoing Percutaneous Coronary Intervention

BACKGROUND

Dialysis patients have strong intracoronary calcification, accelerated by secondary hyperparathyroidism as well as atherosclerosis. We evaluated the association of intact parathyroid hormone (iPTH) level with intracoronary calcification evaluated by intravascular ultrasound (IVUS), and its impact on both stent expansion after percutaneous coronary intervention (PCI) and long-term clinical outcomes, in dialysis patients with coronary artery disease (CAD).Methods and Results: A total of 116 patients on dialysis, who underwent PCI with IVUS guidance between March 2012 and December 2020, were enrolled. Patients were divided into 2 groups based on their median iPTH level. The degree of intracoronary calcification was evaluated by calcification score using grayscale IVUS in the target lesions. Preprocedural calcification scores were significantly higher in the high iPTH group compared with the low iPTH group (2.9±1.1 vs. 2.1±0.7, P<0.001). After PCI, the high iPTH group had a significantly lower stent expansion index (0.6±0.2 vs. 0.7±0.1, P<0.001) and stent symmetry index (0.5±0.1 vs. 0.7±0.1, P<0.001) compared with the low iPTH group. The incidence of major adverse cardiac or cerebrovascular events within 3 years was significantly higher in the high iPTH group (log-rank P<0.05).

CONCLUSIONS

High iPTH level is likely to increase intracoronary calcification, and cause inadequate stent expansion, which may be associated with increased risk of future adverse events in dialysis patients with CAD requiring PCI.

Validation of a simplified intravascular ultrasound core lab analysis method in stented coronary arteries

OBJECTIVES

To validate a simplified core laboratory intravascular ultrasound (IVUS) analysis method based on frames with visually determined minimal lumen areas (MLAs) as compared with a comprehensive (per frame) analysis method.

BACKGROUND

IVUS-guided percutaneous coronary intervention has proven to be superior to angiography-guided stenting. In clinical practice, cross-sections with visually determined MLA are measured to determine lesion severity or minimal stent area (MSA), however, its accuracy has not been compared with a comprehensive per frame analysis method.

METHODS

A total of 50 stented coronary segments of anonymized core lab datasets were analyzed using a comprehensive analysis method and reanalyzed by two core lab analysts using the simplified method including a maximum of seven frames to be analyzed (the visually determined MSA, the first and last frame, and the MLA of each reference segment). The main parameters of interest were MSA, MLA in the reference segments, and plaque burden.

RESULTS

The simplified method showed moderate agreement for measurement of the proximal MLA (7.51 ± 2.52 vs. 6.32 ± 1.88 mm² , intraclass correlation coefficient [ICC] = 0.73), good agreement for the distal MLA (5.41 ± 1.85 vs. 5.11 ± 1.38 mm² , ICC = 0.84) and plaque burden proximal (0.49 ± 0.12 vs. 0.50 ± 0.11, ICC = 0.88), and excellent agreement for the MSA (5.35 ± 1.05 vs. 5.32 ± 0.99 mm² , ICC = 0.94) and plaque burden distal (0.47 ± 0.14 vs. 0.47 ± 0.12, ICC = 0.92), when compared with the comprehensive analysis method. Inter- and intraobserver analysis revealed good-to-excellent agreement for all parameters.

CONCLUSIONS

Measuring poststenting IVUS cross-sections with visually determined MLAs by experienced core lab analysts is an accurate and reproducible method to identify MLAs.

Rotational Atherectomy or Balloon-Based Techniques to Prepare Severely Calcified Coronary Lesions

BACKGROUND

The comparative efficacy of percutaneous techniques for the preparation of calcified lesions before stenting remains poorly studied.

OBJECTIVES

This study sought to compare the performance of up-front rotational atherectomy (RA) or balloon-based techniques before drug-eluting stent implantation in severely calcified coronary lesions as assessed by angiography and optical coherence tomography (OCT).

METHODS

Patient-level data from the PREPARE-CALC (Comparison of Strategies to Prepare Severely Calcified Coronary Lesions) and ISAR-CALC (Comparison of Strategies to Prepare Severely Calcified Coronary Lesions) randomized trials were pooled. The primary endpoint was stent expansion as assessed by OCT imaging. The secondary endpoints included stent eccentricity, stent asymmetry, angiographic acute lumen gain, strategy success and in-hospital occurrence of cardiac death, target vessel myocardial infarction, and repeat revascularization.

RESULTS

Among 274 patients originally randomized, 200 participants with available OCT data after lesion preparation with RA (n = 63), a modified balloon (MB, n = 103), or a super high-pressure balloon (n = 34) before stenting were analyzed. The use of RA versus MB or a super high-pressure balloon led to comparable stent expansion (73.2% ± 11.6% vs 70.8% ± 13.6% vs 71.8% ± 12.2%, P = 0.49) and stent asymmetry (P = 0.83). Compared with RA or MB, a super high-pressure balloon was associated with less stent eccentricity (P = 0.03) with a numerically higher acute lumen gain, albeit not significantly different (P = 0.08). Strategy success was more frequent with RA versus MB (P = 0.002) and numerically more frequent with RA versus a super high-pressure balloon (P = 0.06). Clinical outcomes did not differ between groups.

CONCLUSIONS

In patients with severely calcified lesions undergoing drug-eluting stent implantation, lesion preparation with RA, MB, or a super high-pressure balloon was associated with comparable stent expansion. A super high-pressure balloon is associated with less stent eccentricity, whereas strategy success is more frequent with RA.

Clinical Outcomes and Unique Restenosis of Calcified Nodule in Heavily Calcified Coronary Artery

AIMS

Calcified nodule (CN) has been known as the advanced stage of coronary calcification. However, clinical outcomes following percutaneous coronary intervention (PCI) to CN remain unknown. This study aimed to compare clinical outcomes, including target lesion revascularization (TLR), between calcified coronary lesions with and without CN.

METHODS

Two hundred forty-nine lesions undergoing intravascular ultrasound-guided PCI with rotational atherectomy (RA) were enrolled and divided into the CN group (n=100) and the non-CN group (n=149) according to the presence of CN. The cumulative incidence of clinically driven TLR (CD-TLR) and the reasons for CD-TLR were compared between the CN and non-CN groups.

RESULTS

The incidence of CD-TLR was significantly higher in the CN group than in the non-CN group. In the landmark analysis at 1 year, the CN group showed a significantly higher incidence of CD-TLR within 1 year. However, the incidence of CD-TLR beyond 1 year was numerically lower in the CN group than in the non-CN group. In the multivariate Cox hazard model, CN was significantly associated with CD-TLR. In the CN group, in-stent CN was the major reason for CD-TLR (52%) and was observed mainly within 1 year (90%).

CONCLUSIONS

In the heavily calcified lesions requiring RA, CN was the factor associated with the higher rate of CD-TLR especially within 1 year. The timing of CD-TLR in lesions with CN may indicate that the process of CN protruding through the struts was progressed monthly.

Intravascular imaging in coronary stent restenosis: Prevention, characterization, and management

Despite the introduction of drug-eluting stents to combat the neointimal hyperplasia that occurred after BMS implantation, in-stent restenosis is still encountered in a significant number of patients, particularly as increasingly complex lesions are tackled by percutaneous coronary intervention. Many biological and mechanical factors interplay to produce restenosis, some of which are avoidable. Intravascular imaging provided unique insights into various forms of stent-related mechanical issues that contribute to this phenomenon. From a practical perspective, intravascular imaging can therefore help to optimize the stenting procedure to avert these issues. Moreover, once the problem of restenosis eventuates, imaging can guide the management by tackling the underlying identified mechanism. Finally, it can be used to evaluate the re-intervention results. Nevertheless, with the emergence of different treatment options, more evidence is needed to define patient/lesion-specific characteristics that may help to tailor treatment selection in a way that improves clinical outcomes.

Optimising PCI by Intracoronary Image-guidance

Evidence to support the use of intracoronary imaging (ICI) in guiding percutaneous coronary intervention (PCI) is growing, with observational and randomized controlled trials demonstrating a benefit in acute procedural and clinical outcomes. ICI provides an opportunity to guide PCI, detailing the nature of the coronary disease, potentially influencing lesion preparation and stent selection. Following stent deployment, ICI offers a detailed assessment of lesion coverage, associated vessel trauma and stent expansion. Consensus statements have emphasized the role of ICI and detailed the parameters of stent optimization. However, intracoronary imaging is not adopted widely yet. Significant global differences in the uptake of ICI have been reported, with the vast majority of PCI being angiographically-guided. The three major barriers to the implementation of ICI include, in order of impact, prohibitive cost, prolongation of procedure time and local regulatory issues for use. However, it is our belief that a lack of education and the associated challenges of ICI interpretation provide the greatest barrier to adoption. We hope that this review of the role of ICI in PCI optimization will provide a platform for PCI operators to gain confidence in the utilization of ICI to enhance outcomes for their patients.