Intravascular Ultrasound Versus Angiography-Guided Drug-Eluting Stent Implantation: A Health Economic Analysis

Comparison of Long-Term Outcomes Between Intravascular Ultrasound-, Optical Coherence Tomography- and Angiography-Guided Stent Implantation: A Meta-Analysis

Intravascular ultrasonography (IVUS) and optical coherence tomography (OCT) guided percutaneous coronary interventions (PCI) are alternative techniques to angiography-guided (ANG-g) PCI in patients with coronary artery disease (CAD), especially for optimal stent deployment in coronary arteries. We conducted a network meta-analysis including studies comparing those three techniques. We searched databases for studies that compared IVUS, OCT, and ANG-g PCI in patients with CAD. Overall, 52 studies with 231,137 patients were included in this meta-analysis. ANG-g PCI had higher major adverse cardiovascular events (MACEs), all-cause death, cardiac death, myocardial infarction (MI), target lesion revascularization (TLR), and stent thrombosis (ST) than IVUS-guided PCI. Of note, both OCT-guided and IVUS-guided PCI had similar outcomes. The frequency of MACEs, cardiac death, and MI were higher in ANG-g PCI than in OCT-guided PCI. The highest benefit was established with OCT for MACEs (P-score=.973), MI (P-score=.823), and cardiac death (P-score=.921) and with IVUS for all-cause death (P-score=.792), TLR (P -score=.865), and ST (P-score=.930). This network meta-analysis indicated that using OCT or IVUS for optimal stent implantation provides better outcomes in comparison with ANG-g in patients with CAD undergoing PCI.

Role and Value of Intravascular Ultrasound in the End-Stage Renal Disease Population: A Narrative Review

Vascular access for hemodialysis is the lifeline for patients with end-stage renal disease (ESRD); therefore, maintenance of the vascular access is of the utmost importance. The dialysis circuit can be complicated by stenosis or thrombosis. In particular, central venous stenosis is frequently encountered in the vascular access of patients with ESRD, and this complication may require endovascular management. Conventional catheter-based venography may be inadequate for identifying dynamic forms of extrinsic compression and intravascular webs associated with these lesions. For these types of access complications, balloon angioplasty remains the first-line intervention, with stenting reserved for selected scenarios. Accurate assessment of the venous configuration is therefore important to ensure an adequate treatment response. Intravascular ultrasound (IVUS) has been shown to be beneficial in lower extremity venous interventions. The use of IVUS in dialysis access interventions is currently limited but may be indicated in selected challenging clinical situations. In this article, we discuss the potential uses of IVUS in the ESRD population based on our institutional experience and on the current literature.

Intravascular Imaging-Guided Versus Coronary Angiography-Guided Complex PCI: A Meta-analysis of Randomized Controlled Trials

INTRODUCTION

Trials evaluating the role of intravascular imaging in percutaneous coronary intervention (PCI) for complex coronary artery disease have yielded mixed results. This study aimed to compare the outcomes of intravascular imaging specifically intravascular ultrasound (IVUS) with those from conventional coronary angiography in complex PCI.

METHODS

Comprehensive electronic search of MEDLINE, EMBASE, and Cochrane databases was performed until March 2023 for randomized clinical trials (RCTs) comparing intravascular imaging with coronary angiography in patients undergoing complex PCI. Complex PCI was defined per each study, and included PCI for American College of Cardiology/American Heart Association (ACC/AHA) type B2/C lesions, unprotected left main coronary artery disease, or multivessel stenting. The primary study outcome was major adverse clinical events (MACE).

RESULTS

The meta-analysis included 10 RCTs with a total of 6615 patients (3576 in the intravascular imaging group and 3039 in the coronary angiography group). The weighted mean-follow up was 28.9 months. Compared with coronary angiography, intravascular imaging reduced MACE (8% vs. 13.3%; relative risk [RR] 0.63; 95% confidence interval [CI] 0.54-0.73), cardiac death (RR 0.47; 95% CI 0.31-0.73), definite/probable stent thrombosis (RR 0.48; 95% CI 0.24-0.97), target vessel revascularization (RR 0.62; 95% CI 0.46-0.83), and target lesion revascularization (RR 0.61; 95% CI 0.47-0.79). There was no difference between both groups in all-cause death (RR 0.79; 95% CI 0.53-1.18) and myocardial infarction (RR 0.80; 95% CI 0.61-1.04).

CONCLUSION

In patients undergoing complex PCI, intravascular imaging-specifically IVUS-reduced MACE by decreasing the incidence of cardiac death, stent thrombosis, and target vessel and target lesion revascularization.

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. In this White Paper we summarize 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 nonobstructive coronary disease. The findings presented followed the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system in an expert consensus process that involved a diverse writing group vetted by a review group. Expert consensus was achieved around 9 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, and in 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 who present with myocardial infarction with nonobstructive coronary disease 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 presented in this White Paper will help to guide the use of intravascular imaging toward situations in which the balance of efficacy, safety, and cost are most optimal.

Atherosclerosis evaluation and cardiovascular risk estimation using coronary computed tomography angiography

Clinical risk scores based on traditional risk factors of atherosclerosis correlate imprecisely to an individual's complex pathophysiological predisposition to atherosclerosis and provide limited accuracy for predicting major adverse cardiovascular events (MACE). Over the past two decades, computed tomography scanners and techniques for coronary computed tomography angiography (CCTA) analysis have substantially improved, enabling more precise atherosclerotic plaque quantification and characterization. The accuracy of CCTA for quantifying stenosis and atherosclerosis has been validated in numerous multicentre studies and has shown consistent incremental prognostic value for MACE over the clinical risk spectrum in different populations. Serial CCTA studies have advanced our understanding of vascular biology and atherosclerotic disease progression. The direct disease visualization of CCTA has the potential to be used synergistically with indirect markers of risk to significantly improve prevention of MACE, pending large-scale randomized evaluation.

Absolute zero-contrast percutaneous coronary interventions: An intravascular ultrasound-guided case series and literature review

PURPOSE

Contrast media (CM)-associated adverse effects including mainly acute kidney injury and hypersensitivity reactions still remain a significant treatment burden to vulnerable patients requiring percutaneous coronary intervention (PCI). The complete omission of CM administration accompanied by intravascular ultrasound (IVUS) guidance may offer an appropriate revascularization treatment.

METHODS

We hereby present a case series of four patients with challenging coronary lesions and relative/absolute contraindications to CM use [(hypersensitivity reaction owning to CM, history of contrast-induced acute kidney injury, solitary kidney, or advanced chronic kidney disease (CKD)] who underwent absolute zero-contrast IVUS-guided PCI following a predetermined protocol.

RESULTS

The initial diagnostic angiography was reviewed for landmark identification, and multiple guidewires created a metallic road map providing additional landmarks and protected side branches. IVUS imaging was performed to determine lesion length, reference segments and landing zones, assess stent expansion/apposition and identify major complications. All procedures were successfully completed without any CM administration, renal function deterioration, pericardial effusion, or stent edge dissection.

CONCLUSIONS

We demonstrated the feasibility of absolute zero-contrast IVUS-guided PCI in patients with complex coronary lesions susceptible to CM-associated adverse effects. Since the safety of this strategy is well-documented in patients with CKD and challenging lesions morphology even in acute settings, evidence-based validation of this approach is capable of changing the otherwise conservative treatment of vulnerable patients where even minimum doses of CM may have detrimental effects.

SUMMARY FOR THE ANNOTATED TABLE OF CONTENTS

Patients with vulnerable renal function as well as former hypersensitivity reaction to contrast media encounter a significant treatment burden regarding coronary artery disease. Zero-contrast IVUS-guided strategy based on a predetermined protocol provides a feasible alternative approach in patients susceptible to contrast media-associated adverse effects even in the presence of complex coronary lesions.

The mid-term effect of intravascular ultrasound on endovascular interventions for lower extremity peripheral arterial disease: A systematic review and meta-analysis

OBJECTIVE

Intravascular ultrasound (IVUS) is an important adjunctive tool for patients with lower extremity peripheral arterial disease (PAD) undergoing endovascular therapy (EVT). The evidence regarding the advantages of IVUS use is evolving, and recent studies have reported conflicting results. We aimed to perform a meta-analysis to evaluate the efficacy of IVUS during angiography-guided EVT for patients with PAD.

METHODS

MEDLINE and EMBASE were searched through April 2023 to identify studies that investigated the outcomes of IVUS with angiography-guided EVT vs angiography-alone-guided EVT. The primary outcome was restenosis/occlusion rate; secondary outcomes were target lesion revascularization, major amputation, and mortality.

RESULTS

One randomized controlled trial and 14 observational studies, largely of moderate quality, were included, yielding a total of 708,808 patients with 709,189 lesions that were treated with IVUS-guided EVT (n = 101,405) vs angiography-alone (n = 607,784). Compared with angiography alone, IVUS-guided EVT was associated with a non-significant trend towards decreased restenosis/occlusion (relative risk [RR], 0.74; 95% confidence interval [CI], 0.54-1.00; I2 = 60%). Although the risk of target lesion revascularization and mortality were comparable (RR, 0.85; 95% CI, 0.65-1.10; I2 = 70%; RR, 1.01; 95% CI, 0.79-1.28; I2 = 43%, respectively), the use of IVUS was also associated with significantly lower risk of major amputation (RR, 0.74; 95% CI, 0.67-0.82; I2 = 47%). Subgroup analysis focusing on femoropopliteal disease demonstrated significantly higher patency (RR, 0.72; 95% CI, 0.52-0.98; I2 = 73%). However, superiority with major amputation was not observed.

CONCLUSIONS

IVUS-guided EVT for PAD may possibly be associated with a lower major amputation rate compared with angiography alone-guided EVT, although the difference in patency remained an insignificant trend in favor of IVUS-guided EVT. Adjunctive use of IVUS during EVT may be beneficial, and further prospective studies are warranted to delineate this relationship and the applicability of this technology in routine practice.

Cost-Effectiveness of Intravascular Imaging-Guided Complex PCI: Prespecified Analysis of RENOVATE-COMPLEX-PCI Trial

BACKGROUND

Although clinical benefits of intravascular imaging-guided percutaneous coronary intervention (PCI) in patients with complex coronary artery lesions have been observed in previous trials, the cost-effectiveness of this strategy is uncertain.

METHODS

RENOVATE-COMPLEX-PCI (Randomized Controlled Trial of Intravascular Imaging Guidance vs Angiography-Guidance on Clinical Outcomes After Complex Percutaneous Coronary Intervention) was conducted in Korea between May 2018 and May 2021. This prespecified cost-effectiveness substudy was conducted using Markov model that simulated 3 states: (1) post-PCI, (2) spontaneous myocardial infarction, and (3) death. A simulated cohort was derived from the intention-to-treat population, and input parameters were extracted from either the trial data or previous publications. Cost-effectiveness was evaluated using time horizon of 3 years (within trial) and lifetime. The primary outcome was incremental cost-effectiveness ratio (ICER), an indicator of incremental cost on additional quality-adjusted life years (QALYs) gained, in intravascular imaging-guided PCI compared with angiography-guided PCI. The current analysis was performed using the Korean health care sector perspective with reporting the results in US dollar (1200 Korean Won, ₩=1 dollar, $). Willingness to pay threshold was $35 000 per QALY gained.

RESULTS

A total of 1639 patients were included in the trial. During 3-year follow-up, medical costs ($8661 versus $7236; incremental cost, $1426) and QALY (2.34 versus 2.31; incremental QALY, 0.025) were both higher in intravascular imaging-guided PCI than angiography-guided PCI, resulting incremental cost-effectiveness ratio of $57 040 per QALY gained within trial data. Conversely, lifetime simulation showed total cumulative medical cost was reversed between the 2 groups ($40 455 versus $49 519; incremental cost, -$9063) with consistently higher QALY (8.24 versus 7.89; incremental QALY, 0.910) in intravascular imaging-guided PCI than angiography-guided PCI, resulting in a dominant incremental cost-effectiveness ratio. Consistently, 70% of probabilistic iterations showed cost-effectiveness of intravascular imaging-guided PCI in probabilistic sensitivity analysis.

CONCLUSIONS

The current cost-effectiveness analysis suggests that imaging-guided PCI is more cost-effective than angiography-guided PCI by reducing medical cost and increasing quality-of-life in complex coronary artery lesions in long-term follow-up.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03381872.

Enhancing Coronary Intervention Outcomes Using Intravascular Ultrasound: Analysis of Long-Term Benefits in a Japanese Multicenter Registry

Background

Although the use of intravascular ultrasound (IVUS) during percutaneous coronary intervention (PCI) has been shown to improve clinical outcomes, its utilization remains inconsistent. We aimed to assess the association between IVUS-guided PCI and long-term outcomes in Japan, where a high proportion of patients undergo IVUS.

Methods

We analyzed 8721 consecutive patients in a multicenter PCI registry. The primary outcome was a composite of death, acute coronary syndrome, and heart failure requiring admission and coronary artery bypass grafting at 2 years after discharge. The secondary outcome was each component of the primary outcome. We used inverse probability-weighted analysis for adjustment. Subgroup analysis was conducted on patients with complex coronary anatomy (eg, those with bifurcation, chronic total occlusion, type C lesion, left main and those who underwent rotational atherectomy).

Results

Overall, 83.8% of patients underwent IVUS-guided PCI (mean age, 68.3 ± 11.3 years). After adjustments, the IVUS group had significantly lower rates of death and coronary bypass compared to no IVUS group (hazard ratio [HR], 0.73; 95% CI, 0.55-0.96; and HR, 0.62; 95% CI, 0.39-0.98) at 2-year follow-up, although the primary outcome showed only marginal differences (HR, 0.85; 95% CI, 0.71-1.01). In the subgroup analysis of complex coronary anatomy, the use of IVUS was significantly associated with a reduced risk of the primary outcome (HR, 0.72; 95% CI, 0.55-0.93) as well as death, coronary bypass, and heart failure.

Conclusions

IVUS was frequently utilized in our registry and demonstrated potential benefit in reducing mortality and need for coronary bypass surgery, particularly in patients with complex coronary anatomy.

CVIT 2023 clinical expert consensus document on intravascular ultrasound

Intravascular ultrasound (IVUS) provides precise anatomic information in coronary arteries including quantitative measurements and morphological assessment. To standardize the IVUS analysis in the current era, this updated expert consensus document summarizes the methods of measurements and assessment of IVUS images and the clinical evidence of IVUS use in percutaneous coronary intervention.

Real-world long-term survival after non-emergent percutaneous coronary intervention to unprotected left main coronary artery - From the Melbourne Interventional Group (MIG) registry

BACKGROUND

Current evidence suggests that percutaneous coronary intervention for unprotected left main coronary artery disease (LMPCI) in selected patients is a safe alternative to coronary artery bypass grafting. However, real-world long-term survival data is limited.

METHODS

We analyzed 24,644 patients from the MIG (Melbourne Interventional Group) registry between 2005 and 2020. We compared baseline clinical and procedural characteristics, in-hospital and 30-day outcomes, and long-term survival between unprotected LMPCI and non-LMPCI among patients without ST-segment elevation myocardial infarction, cardiogenic shock, or cardiac arrest.

RESULTS

Unprotected LMPCI patients (n = 185) were significantly older (mean age 72.0 vs. 64.6 years, p < 0.001), had higher prevalence of impaired ejection fraction (EF <50 %; 27.3 % vs. 14.9 %, p < 0.001) and lower estimated glomerular filtration rate < 60 ml/min/1.73m2 (40.9 % vs. 21.5 %, p < 0.001), and had greater use of intravascular ultrasound (21 % vs. 1 %, p < 0.001) and drug-eluting stents (p < 0.001). LMPCI was associated with longer hospital stay (4 days vs. 2 days, p < 0.001). There was no significant difference in other in-hospital outcomes, 30-day mortality (0.6 % vs. 0.6 %, p = 0.90), and major adverse cardiac events (1.7 % vs. 3 %, p = 0.28). Although the unadjusted Kaplan-Meier survival to 8 years was significantly less with LMPCI compared to non-LMPCI (p < 0.01), LMPCI was not a predictor of long-term survival up to 8 years after Cox regression analysis (HR 0.67, 95 % CI 0.40-1.13, p = 0.13).

CONCLUSION

In this study, non-emergent unprotected LMPCI was uncommonly performed, and IVUS was underutilized. Despite greater co-morbidities, LMPCI patients had comparable 30-day outcomes to non-LMPCI, and LMPCI was not an independent predictor of long-term mortality.

Intravascular imaging guided versus coronary angiography guided percutaneous coronary intervention: systematic review and meta-analysis

OBJECTIVE

To assess the absolute treatment effects of intravascular imaging guided versus angiography guided percutaneous coronary intervention in patients with coronary artery disease, considering their baseline risk.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed/Medline, Embase, and Cochrane Library databases up to 31 August 2023.

STUDY SELECTION

Randomized controlled trials comparing intravascular imaging (intravascular ultrasonography or optical coherence tomography) guided versus coronary angiography guided percutaneous coronary intervention in adults with coronary artery disease.

MAIN OUTCOME MEASURES

Random effect meta-analysis and GRADE (grading of recommendations, assessment, development, and evaluation) were used to assess certainty of evidence. Data included rate ratios and absolute risks per 1000 people for cardiac death, myocardial infarction, stent thrombosis, target vessel revascularization, and target lesion revascularization. Absolute risk differences were estimated using SYNTAX risk categories for baseline risks at five years, assuming constant rate ratios across different cardiovascular risk thresholds.

RESULTS

In 20 randomized controlled trials (n=11 698), intravascular imaging guided percutaneous coronary intervention was associated with a reduced risk of cardiac death (rate ratio 0.53, 95% confidence interval 0.39 to 0.72), myocardial infarction (0.81, 0.68 to 0.97), stent thrombosis (0.44, 0.27 to 0.72), target vessel revascularization (0.74, 0.61 to 0.89), and target lesion revascularization (0.71, 0.59 to 0.86) but not all cause death (0.81, 0.64 to 1.02). Using SYNTAX risk categories, high certainty evidence showed that from low risk to high risk, intravascular imaging was likely associated with 23 to 64 fewer cardiac deaths, 15 to 19 fewer myocardial infarctions, 9 to 13 fewer stent thrombosis events, 28 to 38 fewer target vessel revascularization events, and 35 to 48 fewer target lesion revascularization events per 1000 people.

CONCLUSIONS

Compared with coronary angiography guided percutaneous coronary intervention, intravascular imaging guided percutaneous coronary intervention was associated with significantly reduced cardiac death and cardiovascular outcomes in patients with coronary artery disease. The estimated absolute effects of intravascular imaging guided percutaneous coronary intervention showed a proportional relation with baseline risk, driven by the severity and complexity of coronary artery disease.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42023433568.

Intravascular imaging during percutaneous coronary intervention: temporal trends and clinical outcomes in the USA

AIMS

Prior trials have demonstrated that intravascular imaging (IVI)-guided percutaneous coronary intervention (PCI) results in less frequent target lesion revascularization and major adverse cardiovascular events (MACEs) compared with standard angiographic guidance. The uptake and associated outcomes of IVI-guided PCI in contemporary clinical practice in the USA remain unclear. Accordingly, temporal trends and comparative outcomes of IVI-guided PCI relative to PCI with angiographic guidance alone were examined in a broad, unselected population of Medicare beneficiaries.

METHODS AND RESULTS

Retrospective cohort study of Medicare beneficiary data from 1 January 2013, through 31 December 2019 to evaluate temporal trends and comparative outcomes of IVI-guided PCI as compared with PCI with angiography guidance alone in both the inpatient and outpatient settings. The primary outcomes were 1 year mortality and MACE, defined as the composite of death, myocardial infarction (MI), repeat PCI, or coronary artery bypass graft surgery. Secondary outcomes were MI or repeat PCI at 1 year. Multivariable Cox regression was used to estimate the adjusted association between IVI guidance and outcomes. Falsification endpoints (hospitalized pneumonia and hip fracture) were used to assess for potential unmeasured confounding. The study population included 1 189 470 patients undergoing PCI (38.0% female, 89.8% White, 65.1% with MI). Overall, IVI was used in 10.5% of the PCIs, increasing from 9.5% in 2013% to 15.4% in 2019. Operator IVI use was variable, with the median operator use of IVI 3.92% (interquartile range 0.36%-12.82%). IVI use during PCI was associated with lower adjusted rates of 1 year mortality [adjusted hazard ratio (aHR) 0.96, 95% confidence interval (CI) 0.94-0.98], MI (aHR 0.97, 95% CI 0.95-0.99), repeat PCI (aHR 0.74, 95% CI 0.73-0.75), and MACE (aHR 0.85, 95% CI 0.84-0.86). There was no association with the falsification endpoint of hospitalized pneumonia (aHR 1.02, 95% CI 0.99-1.04) or hip fracture (aHR 1.02, 95% CI 0.94-1.10).

CONCLUSION

Among Medicare beneficiaries undergoing PCI, use of IVI has increased over the previous decade but remains relatively infrequent. IVI-guided PCI was associated with lower risk-adjusted mortality, acute MI, repeat PCI, and MACE.

Outcomes of Intravascular Ultrasound-Guided Percutaneous Coronary Intervention Among Patients With Acute Coronary Syndrome

Intravascular ultrasound (IVUS) use in percutaneous coronary intervention (PCI) improves outcomes. However, data on outcomes of IVUS-guided PCI in patients presenting with acute coronary syndrome (ACS) is scarce. Therefore, we sought to study the utilization rate and outcomes of IVUS-guided PCI in patients with ACS. Using the National Readmission database, we identified all patients with ACS who underwent PCI from 2016 to 2019. We used a 1:1 propensity-matched analysis to compare the outcome of patients with ACS who underwent PCI with and without IVUS. In 1,263,997 patients with ACS, 563,521 (44.6%) underwent PCI without IVUS and 40,095 (3.17%) underwent IVUS-guided PCI. A Propensity scored matched comparison of PCI with and without IVUS showed IVUS-guided PCI was associated with a lower risk of in-hospital mortality (odds ratio 0.74, 95% confidence interval 0.64 to 0.85, p <0.01) compared with PCI without IVUS. The utilization of IVUS increased from 2.64% in 2016 to 4.10% in 2019, p <0.001. In conclusion, IVUS-guided PCI is associated with lower in-hospital mortality in patients with ACS, yet the current utilization of IVUS-guided PCI remains low across the United States.

Intracoronary Imaging Versus Coronary Angiography Guidance for Implantation of Second and Third Generation Drug Eluting Stents in a Systematic Review and Meta-Analysis of Randomized Controlled Trials

Intracoronary imaging (ICI) facilitates stent implant by characterizing the lesion calcification, providing accurate vessel dimensions, and optimizing the stent results. We sought to investigate the outcomes of routine ICI versus coronary angiography (CA) to guide percutaneous coronary intervention (PCI) with second- and third-generation drug-eluting stents. A systematic search of PubMed, Medline, and Cochrane databases was conducted from their inception to July 16, 2022 for randomized controlled trials comparing routine ICI with CA. The primary outcome was major adverse cardiovascular events. The secondary outcomes of interest were target lesion revascularization, target vessel revascularization, myocardial infarction, stent thrombosis, and cardiac and all-cause mortality. A random-effects model was used to calculate the pooled incidence and relative risk (RR) with 95% confidence intervals (CIs). A total of 9 randomized controlled trials with 5,879 patients (2,870 ICI-guided and 3,009 CA-guided PCI) met the inclusion criteria. The ICI and CA groups were similar in demographic characteristics and co-morbidity profiles. Compared with CA, patients in the routine ICI-guided PCI group had lower rates of major adverse cardiovascular events (RR 0.61, 95% CI 0.48 to 0.78, p <0.0001), target lesion revascularization (RR 0.60, 95% CI 0.43 to 0.83, p = 0.002), target vessel revascularization (RR 0.72, 95% CI 0.51 to 1.00, p = 0.05), and myocardial infarction (RR 0.48, 95% CI 0.25 to 0.95, p = 0.03). There were no significant differences in stent thrombosis or cardiac/all-cause mortality between the 2 strategies. In conclusion, routine ICI-guided PCI strategy, compared with CA guidance alone, is associated with improved clinical outcomes, largely driven by lower repeat revascularization.

Accuracy of IVUS-Based Machine Learning Segmentation Assessment of Coronary Artery Dimensions and Balloon Sizing

Background

Accurate intravascular ultrasound (IVUS) measurements are important in IVUS-guided percutaneous coronary intervention optimization by choosing the appropriate device size and confirming stent expansion.

Objectives

The purpose of this study was to assess the accuracy of machine learning (ML) automatic segmentation of coronary artery vessel and lumen dimensions and balloon sizing.

Methods

Using expert analysis as the gold standard, ML segmentation of 60 MHz IVUS images was developed using 8,076 IVUS cross-sectional images from 234 patients, which were randomly split into training (83%) and validation (17%) data sets. The performance of ML segmentation was then evaluated using an independent test data set (437 images from 92 patients). The endpoints were the agreement rate between ML vs experts' measurements for appropriate balloon size selection, and lumen and acute stent areas. Appropriate balloon size was determined by rounding down from the mean vessel diameter or rounding up from the mean lumen diameter to the next balloon size. The difference of lumen area ≥0.5 mm2 was considered as clinically significant.

Results

ML model segmentation correlated well with experts' segmentation for training data set with a correlation coefficient of 0.992 and 0.993 for lumen and vessel areas, respectively. The agreement rate in lumen and acute stent areas was 85.5% and 97.0%, respectively. The agreement rate for appropriate balloon size selection was 70.6% by vessel diameter only and 92.4% by adding lumen diameter.

Conclusions

ML model IVUS segmentation measurements were well-correlated with those of experts and selected an appropriate balloon size in more than 90% of images.

Role of Intravascular Ultrasound in Pulmonary Embolism Patients Undergoing Mechanical Thrombectomy: A Systematic Review

BACKGROUND

Traditionally, mechanical thrombectomy performed for pulmonary embolism (PE) necessitates the utilization of iodinated contrast. Intravascular ultrasound (IVUS) has been used as a diagnostic and therapeutic modality in the management of acute high and intermediate-risk PE. Recently, with the shortage of contrast supplies and the considerable incidence of contrast-induced acute kidney injury (CI-AKI), other safer and more feasible IVUS methods have become desirable. The purpose of this systematic review was to evaluate the importance of IVUS in patients with PE undergoing thrombectomy.

METHODS

Medline/PubMed, Embase, Scopus, and Google Scholar were searched for review studies, case reports, and case series. Clinical characteristics, outcomes and the usage of IVUS-guided mechanical thrombectomy during the treatment of acute high and intermediate-risk PE were examined in a descriptive analysis.

RESULTS

In this systematic review, we included one prospective study, two case series, and two case reports from July 2019 to May 2023. A total of 39 patients were evaluated; most were female (53.8%). The main presenting symptoms were dyspnea and chest pain (79.5%); three patients (7.9%) presented with syncope, one with shock and one with cardiac arrest. Biomarkers (troponin and BNP) were elevated in 94.6% of patients. Most patients (87.2%) had intermediate-risk PE, and 12.8% had high-risk PE. All patients presented with right-heart strain (RV/LV ratio ≥ 0.9, n = 39). Most patients (56.4%) had bilateral PE. Mechanical thrombectomy was performed using IVUS without contrast utilization in 39.4% of the patients. After the initial learning curve, contrast usage decreased gradually over time. There was a significant decrease in the composite mean arterial pressure immediately following IVUS-guided thrombectomy from 35.1 ± 7.2 to 25.2 ± 8.3 mmHg (p < 0.001). Post-procedure, there was no reported (0%) CI-AKI, no all-cause mortality, no major bleeding, or other adverse events. There was a significant improvement in symptoms and RV function at the mean follow-up.

CONCLUSIONS

New evidence suggests that IVUS-guided mechanical thrombectomy is safe, with visualization of the thrombus for optimal intervention, and reduces contrast exposure.

Intravascular Ultrasound Guidance During Peripheral Vascular Interventions: Long-term Clinical Outcomes and Costs From the Japanese Perspective

PURPOSE

The value of intravascular ultrasound (IVUS) guidance during peripheral vascular revascularization procedures is incompletely understood. Moreover, data on long-term clinical outcomes and costs are limited. The objective of this study was to compare outcomes and costs between IVUS and contrast angiography alone in patients undergoing peripheral revascularization procedures in Japan.

MATERIALS AND METHODS

This retrospective comparative analysis was performed using the Japanese Medical Data Vision insurance claims database. All patients undergoing revascularization for peripheral artery disease (PAD) between April 2009 and July 2019 were included. Patients were followed until July 2020, death, or a subsequent revascularization procedure for PAD. Two patient groups were compared: one undergoing IVUS imaging or the other contrast angiography alone. The primary end point was major adverse cardiac and limb events, including all-cause-mortality, endovascular thrombolysis, subsequent revascularization procedures for PAD, stroke, acute myocardial infarction, and major amputations. Total health care costs were documented over the follow-up and compared between groups, using a bootstrap method.

RESULTS

The study included 3956 patients in the IVUS group and 5889 in the angiography alone group. Intravascular ultrasound was significantly associated with reduced risk of a subsequent revascularization procedure (adjusted hazard ratio: 0.25 [0.22-0.28]) and major adverse cardiac and limb events (0.69 [0.65-0.73]). The total costs were significantly lower in the IVUS group, with a mean cost saving over follow-up of $18 173 [$7 695-$28 595] per patient.

CONCLUSION

The use of IVUS during peripheral revascularization provides superior long-term clinical outcomes at lower costs compared with contrast angiography alone, warranting wider adoption and fewer barriers to IVUS reimbursement for patients with PAD undergoing routine revascularization.

CLINICAL IMPACT

Intravascular ultrasound (IVUS) guidance during peripheral vascular revascularization has been introduced to improve the precision of the procedure. However, questions over the benefit of IVUS in terms of long-term clinical outcome and over cost have limited its use in everyday clinical practice. This study, performed in a Japanese health insurance claims database, demonstrates that use of IVUS provides a superior clinical outcome over the long term at a lower cost compared to angiography alone. These findings should encourage clinicians to use IVUS in routine peripheral vascular revascularization procedures and encourage providers to reduce barriers to use.

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.

Trends in the cost-effectiveness level of percutaneous coronary intervention: Macro socioeconomic analysis and health technology assessment

Percutaneous coronary intervention (PCI), one of the most prevalent techniques of revascularization, is a procedure that remarkably improves treatment outcomes. However, it consumes large amounts of medical resources and has resulted in an increased socioeconomic burden due to the increasing number of target patients. In recent years, there have been sporadic discussions, both in Japan and other countries, regarding the optimization of interventions and the perspective of medical economics. Based on this, previous studies on PCI-related cost-effectiveness were reviewed in order to consider the current level of medical economics regarding PCI. Using the databases MEDLINE and EMBASE, a survey involving data from original articles and systematic reviews was conducted from January 2010 to August 2022. Conditions were not imposed on the evidence level due to the paucity of studies, although field studies were prioritized over simulation studies. The macro medical economics of acute myocardial infarction treatment, which is the primary target of PCI, were generally at an average level when compared to those in other countries; however, there is room for further improvement in Japan's performance. Revascularization in a population with multivessel coronary artery disease showed that coronary artery bypass graft surgery tended to be more cost-effective than PCI in the long-term setting. However, it was suggested that PCI may be more cost-effective in patients with SYNTAX Score ≤22 or left main artery disease. A cost-effectiveness report for stable angina patients was not in favor of PCI over medical therapy. Moreover, there were some reports showing the medical economic superiority of early myocardial ischemia evaluation, and it was foreseen that active selection of patients will contribute to the improvement of the overall cost-effectiveness of PCI. In order to further improve the socioeconomic significance of PCI in the future, it is necessary to aim for harmony between clinical practice and health economics.

Physical Therapists Use of Diagnostic Ultrasound Imaging in Clinical Practice: A Review of Case Reports

Objective

Ultrasound diagnostic imaging (USI) is widely utilized in sports medicine, orthopaedics, and rehabilitation. Its use in physical therapy clinical practice is increasing. This review summarizes published patient case reports describing USI in physical therapist practice.

Design

Comprehensive literature review.

Literature Search

PubMed was searched using the keywords "physical therapy" AND "ultrasound" AND "case report" AND "imaging". In addition, citation indexes and specific journals were searched.

Study Selection Criteria

Papers were included if the patient was attending physical therapy, USI was necessary for patient management, the full text was retrievable, and the paper was written in English. Papers were excluded if USI was only used for interventions, such as biofeedback, or if the USI was incidental to physical therapy patient/client management.

Data Synthesis

Categories of data extracted included: 1) Patient presentation; 2) Setting; 3) Clinical indications; 4) Who performed USI; 5) Anatomical region; 6) Methods of USI; 7) Additional imaging; 8) Final diagnosis; and 9) Case outcome.

Results

Of the 172 papers reviewed for inclusion, 42 were evaluated. Most common anatomical regions scanned were the foot and lower leg (23%), thigh and knee (19%), shoulder and shoulder girdle (16%), lumbopelvic region (14%), and elbow/wrist and hand (12%). Fifty-eight percent of the cases were deemed static, while 14% reported using dynamic imaging. The most common indication for USI was a differential diagnosis list that included serious pathologies. Case studies often had more than one indication. Thirty-three cases (77%) resulted in confirmation of a diagnosis, while 29 case reports (67%) documented significant changes in physical therapy intervention strategies due to the USI, and 25 case reports (63%) resulted in referral.

Conclusion

This review of cases provides details on unique ways USI can be used during physical therapy patient care, including aspects that reflect the unique professional framework.

Optical coherence tomography in coronary atherosclerosis assessment and intervention

Since optical coherence tomography (OCT) was first performed in humans two decades ago, this imaging modality has been widely adopted in research on coronary atherosclerosis and adopted clinically for the optimization of percutaneous coronary intervention. In the past 10 years, substantial advances have been made in the understanding of in vivo vascular biology using OCT. Identification by OCT of culprit plaque pathology could potentially lead to a major shift in the management of patients with acute coronary syndromes. Detection by OCT of healed coronary plaque has been important in our understanding of the mechanisms involved in plaque destabilization and healing with the rapid progression of atherosclerosis. Accurate detection by OCT of sequelae from percutaneous coronary interventions that might be missed by angiography could improve clinical outcomes. In addition, OCT has become an essential diagnostic modality for myocardial infarction with non-obstructive coronary arteries. Insight into neoatherosclerosis from OCT could improve our understanding of the mechanisms of very late stent thrombosis. The appropriate use of OCT depends on accurate interpretation and understanding of the clinical significance of OCT findings. In this Review, we summarize the state of the art in cardiac OCT and facilitate the uniform use of this modality in coronary atherosclerosis. Contributions have been made by clinicians and investigators worldwide with extensive experience in OCT, with the aim that this document will serve as a standard reference for future research and clinical application.

The Continuum of Invasive Techniques for the Assessment of Intermediate Coronary Lesions

Ischemic heart disease is one of the most important causes of mortality and morbidity worldwide. Revascularization of coronary stenosis inducing ischemia, either by percutaneous or surgical intervention, significantly reduces major adverse cardiovascular events and improves quality of life. However, in cases of intermediate lesions, classified by a diameter stenosis between 50 and 90% by European guidelines and 40–70% in American counterparts with no clear evidence of ischemia, the indication of revascularization and impact is determined using various methods that altogether comprehensively evaluate the lesions. This review will discuss the various techniques to assess intermediate stenoses, highlighting indications and advantages, but also drawbacks. Fractional flow rate (FFR) and instantaneous wave-free ratio (iFR) are the gold standard for the functional evaluation of intermediate lesions, but there are clinical circumstances in which these pressure-wire-derived indices are not accurate. Complementary invasive investigations, mainly intravascular ultrasound and/or optical coherence tomography, offer parameters that can be correlated with FFR/iFR and additional insights into the morphology of the plaque guiding the eventual percutaneous intervention in terms of length and size of stents, thus improving the outcomes of the procedure. The development of artificial intelligence and machine learning with advanced algorithms of prediction will offer multiple scenarios for treatment, allowing real-time selection of the best strategy for revascularization.

Dual-Resonance (16/32 MHz) Piezoelectric Transducer With a Single Electrical Connection for Forward-Viewing Robotic Guidewire

Peripheral artery disease (PAD) affects more than 200 million people globally. Minimally invasive endovascular procedures can provide relief and salvage limbs while reducing injury rates and recovery times. Unfortunately, when a calcified chronic total occlusion is encountered, ~25% of endovascular procedures fail due to the inability to advance a guidewire using the view provided by fluoroscopy. To enable a sub-millimeter, robotically steerable guidewire to cross these occlusions, a novel single-element, dual-band transducer is developed that provides simultaneous multifrequency, forward-viewing imaging with high penetration depth and high spatial resolution while requiring only a single electrical connection. The design, fabrication, and acoustic characterization of this device are described, and proof-of-concept imaging is demonstrated in an ex vivo porcine artery after integration with a robotically steered guidewire. Measured center frequencies of the developed transducer were 16 and 32 MHz, with -6 dB fractional bandwidths of 73% and 23%, respectively. When imaging a 0.2-mm wire target at a depth of 5 mm, measured -6 dB target widths were 0.498 ± 0.02 and 0.268 ± 0.01 mm for images formed at 16 and 32 MHz, respectively. Measured SNR values were 33.3 and 21.3 dB, respectively. The 3-D images of the ex vivo artery demonstrate high penetration for visualizing vessel morphology at 16 MHz and ability to resolve small features close to the transducer at 32 MHz. Using images acquired simultaneously at both frequencies as part of an integrated forward-viewing, guidewire-based imaging system, an interventionalist could visualize the best path for advancing the guidewire to improve outcomes for patients with PAD.

Estimating the economic impacts of percutaneous coronary intervention in Australia: a registry-based cost burden study

OBJECTIVES

In this study, we sought to evaluate the costs of percutaneous coronary intervention (PCI) across a variety of indications in Victoria, Australia, using a direct per-person approach, as well as to identify key cost drivers.

DESIGN

A cost-burden study of PCI in Victoria was conducted from the Australian healthcare system perspective.

SETTING

A linked dataset of patients admitted to public hospitals for PCI in Victoria was drawn from the Victorian Cardiac Outcomes Registry (VCOR) and the Victorian Admitted Episodes Dataset. Generalised linear regression modelling was used to evaluate key cost drivers. From 2014 to 2017, 20 345 consecutive PCIs undertaken in Victorian public hospitals were captured in VCOR.

PRIMARY OUTCOME MEASURES

Direct healthcare costs attributed to PCI, estimated using a casemix funding method.

RESULTS

Key cost drivers identified in the cost model included procedural complexity, patient length of stay and vascular access site. Although the total procedural cost increased from $A55 569 740 in 2014 to $A72 179 656 in 2017, mean procedural costs remained stable over time ($A12 521 in 2014 to $A12 185 in 2017) after adjustment for confounding factors. Mean procedural costs were also stable across patient indications for PCI ($A9872 for unstable angina to $A15 930 for ST-elevation myocardial infarction) after adjustment for confounding factors.

CONCLUSIONS

The overall cost burden attributed to PCIs in Victoria is rising over time. However, despite increasing procedural complexity, mean procedural costs remained stable over time which may be, in part, attributed to changes in clinical practice.

Clinical expert consensus document on intravascular ultrasound from the Japanese Association of Cardiovascular Intervention and Therapeutics (2021)

Intravascular ultrasound (IVUS) provides precise anatomic information in coronary arteries including quantitative measurements and morphological assessment. To standardize the IVUS analysis in the current era, this updated expert consensus document summarizes the methods of measurements and assessment of IVUS images and the clinical evidence of IVUS use in percutaneous coronary intervention.