Current clinical use of intravascular ultrasound imaging to guide percutaneous coronary interventions

Treatment strategies and in-hospital mortality in patients with type A acute aortic dissection and coronary artery involvement

OBJECTIVE

Type A acute aortic dissection (AAD), especially that with coronary artery involvement and malperfusion, is a life-threatening disease. In the present study we aimed to investigate the association of surgical treatment and percutaneous coronary intervention (PCI) with in-hospital mortality in patients with type A AAD and coronary artery involvement.

METHODS

This retrospective multicenter registry in Japan included 225 patients with type A AAD and coronary artery involvement. Treatment strategies including surgical treatment and/or PCI were left to treating physicians. The primary end point was in-hospital death.

RESULTS

Of 225 patients, dissection extended into the right and left coronary arteries and both in 115 (51.1%), 105 (46.7%), and 5 (2.2%), respectively. Overall, 94 (41.8%) patients died during the hospitalization. Coronary angiography was performed in 53 (23.6%) patients, among whom 39 (73.6%) underwent PCI. Surgical repair was performed in 188 (83.6%) patients. In patients who received neither procedure, 33 of 35 (94.3%) died during the hospitalization. PCI was performed as a bridge to surgical repair in 37 of 39 (94.9%) patients, and in-hospital mortality of patients who underwent PCI and surgical procedures was 24.3%. Multivariable analysis identified PCI and surgical procedures as factors associated with lower in-hospital mortality rates.

CONCLUSIONS

Coronary artery involvement in type A AAD was associated with high in-hospital mortality of more than 40% in the current era. An early reperfusion strategy with PCI as a bridge to surgical repair might improve clinical outcomes in this fatal condition.

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.

Evaluation of Cholesterol Thickness of Blood Vessels Using Photoacoustic Technology

One of the primary indicators of plaque vulnerability is the lipid composition of atherosclerotic plaques. Therefore, the medical industry requires a method to evaluate necrotic nuclei in atherosclerosis imaging with sensitivity. In this regard, photoacoustic imaging is a plaque detection method that provides chemical information on lipids and cholesterol thickness in the arterial walls of the patient. This aspect aims to increase the low-frequency axial resolution by developing a new photoacoustic-based system. A photoacoustic system has been developed to detect the cholesterol thickness of the blood vessels to observe the progression of plaque in the heart's blood vessels. The application of the coherent photoacoustic discontinuous correlation tomography technique, which is based on a novel signal processing, significantly increased the cholesterol oleate's sensitivity to plaque necrosis. By enhancing the quality of thickness detection, the system for measuring the thickness of cholesterol in blood vessels has been reduced to approximately 23 microns. The results show that the phase spectrum peaked at 100 Hz at 58.66 degrees, and at 400 Hz, the phase spectrum was 46.37 degrees. The minimum amplitude is 1.95 at 100 Hz and 17.67 at 400 Hz. In conclusion, it can be stated that photoacoustic imaging as a method based on new technologies is of great importance in medical research, which is based on the use of nonionizing radiation to perform diagnostic processes and measure different types of body tissues.

Intravascular Ultrasound in Vulnerable Plaque and Acute Coronary Syndrome

Vulnerable plaque plays a pivotal role in the pathogenesis of acute coronary syndrome (ACS), being responsible for most ACS. The concept of vulnerable plaque has evolved with advancements in basic and clinical investigations along with developments and rapid expansion of coronary imaging modalities. Intravascular ultrasound (IVUS) is the first widely applied clinical technology with sufficient tissue penetration and enables us to identify vulnerable plaque and comprehensively understand the pathophysiology of ACS. In this review, we summarize current clinical evidence established by IVUS and the recent advancements in our understanding of vulnerable plaque and its role in ACS management.

Intravascular Ultrasound-Guided Percutaneous Coronary Intervention: Practical Application

Why is intravascular ultrasounography (IVUS) highly encouraged for the practical guidance of percutaneous coronary intervention (PCI)? First reason is to understand the mechanism of revascularization. Even if stenoses look similar in angiography, the pathophysiology could be different in each lesion. Second reason is to anticipate possible complications in advance. With prediction and appropriate preparation, most complications can be avoided or managed calmly when they occur. Third reason is to optimize PCI results with interactive IVUS use during the procedure. All these are essential to maximize the results of revascularization while minimizing acute complications, ultimately leading to improved long-term clinical outcomes.

Impact of myocardial bridge on non-culprit vessel lumen changes in patients with acute coronary syndrome

This study aims to clarify the impact of myocardial bridge (MB) on the presence and progression of atherosclerosis in left descending coronary artery (LAD) in patients with acute coronary syndrome (ACS). Ninety-eight patients who underwent percutaneous coronary intervention with the diagnosis of ACS and follow-up coronary angiography but had no significant stenosis in the LAD were included. MB was defined based on coronary angiography. Quantitative coronary angiography was performed to determine the segments where MB was present and proximal to the MB (proximal segment) in patients with MB. In patients without MB, a corresponding region was quantitatively analyzed. The primary endpoint was changes in minimum lumen diameter (MLD) and percentage of diameter stenosis (%DS) in the proximal segment from baseline to follow-up angiography, namely ΔMLD and Δ%DS. MB was identified in 29 (29.6%) patients. Patients with MB had larger MLD and smaller %DS in the proximal segment than their counterpart. During the mean follow-up period of 12.9 ± 5.7 months, MLD and %DS in the proximal segment did not change significantly from baseline to follow-up in patients with and without MB. No significant between-group differences were observed in ΔMLD and Δ%DS. Baseline MLD was identified as the only factor associated with ΔMLD in the proximal segment. ACS patients who had MB but no significant stenosis in the LAD had larger MLD and smaller %DS at the segment proximal to MB compared to those without. In this selected population, serial lumen changes assessed by ΔMLD were not associated with the presence of MB in the LAD.

Current clinical use of intravascular ultrasound imaging to guide percutaneous coronary interventions (update)

There are 3 main reasons to promote the practical application of IVUS during PCI. First reason is to understand the mechanism of vessel dilatation. Even if angiographic stenoses are similar, their pathophysiologies are different. It is important to understand what can happen by dilating coronary artery with balloon/stent, and to develop a strategy to achieve the maximum effect. Second reason is to anticipate possible complications and to reduce them in advance. In that case, we can deal with it as calmly as possible. Third reason is to validate the PCI performed. This should lead to further improvements of the procedures, which in turn will lead to improved short- and long-term prognosis. Then, high-quality PCI could be possible. This review summarizes the standard usage of IVUS in routine clinical practice and the use of IVUS in specific situations, especially complex lesions.

Clinical Characteristics and Prognosis of Patients With No Standard Modifiable Risk Factors in Acute Myocardial Infarction

BACKGROUND

Recently, the impact of the lack of standard modifiable risk factors, including hypertension, diabetes, dyslipidaemia, and current smoking, has been investigated in ST-segment elevation myocardial infarction (MI). The present study aimed to evaluate clinical characteristics and prognosis of the patients with no standard risk factors in acute MI.

METHODS

This bi-centre registry included 1,093 patients with acute MI undergoing percutaneous coronary intervention. The participants were divided into two groups: patients having at least one of the four standard risk factors and those having none of the risk factors. The study endpoints included major adverse cardiovascular events (MACE) (death, recurrent MI, and stroke) and major bleeding events during hospitalisation. Any MACE and major bleeding events after discharge were also evaluated as an exploratory analysis.

RESULTS

Of 1,093 patients, 64 (5.9%) had none of the four standard risk factors. The patients with no standard risk factors were likely to present with Killip class IV and cardiac arrest. The rate of in-hospital MACE was higher in patients with no risk factors than in their counterparts (25.0% vs 9.9%; p<0.001), whereas the incidence of in-hospital major bleeding was not significantly different between the two groups (9.4% vs 6.7%; p=0.44). Active cancer and autoimmune/inflammatory diseases were often found in patients with no standard risk factors. After discharge, no significant differences were observed in the risks of MACE and major bleeding events between the two groups.

CONCLUSIONS

No standard modifiable risk factors were not uncommon and were associated with poor short-term outcomes in patients with acute MI.

High-resolution sub-millimetre diameter side-viewing all-optical ultrasound transducer based on a single dual-clad optical fibre

All-optical ultrasound (OpUS), where ultrasound is both generated and received using light, has emerged as a modality well-suited to highly miniaturised applications. In this work we present a proof-of-concept OpUS transducer built onto a single optical fibre with a highly miniaturised lateral dimension (<0.8 mm). A key innovation was to use a dual-clad optical fibre (DCF) to provide multimode light for ultrasound generation and single mode light for ultrasound reception. The transducer comprised a proximal section of DCF spliced to a short section of single mode fibre (SMF). Multimode light was outcoupled at the splice joint and guided within a square capillary to provide excitation for ultrasound generation. Whilst single mode light was guided to the distal tip of the SMF to a plano-concave microresonator for ultrasound reception. The device was capable of generating ultrasound with pressures >0.4 MPa and a corresponding bandwidth >27 MHz. Concurrent ultrasound generation and reception from the transducer enabled imaging via motorised pull-back allowing image acquisition times of 4 s for an aperture of 20 mm. Image resolution was as low as ~50 µm and 190 µm in the axial and lateral extents, respectively, without the need for image reconstruction. Porcine aorta was imaged ex vivo demonstrating detailed ultrasound images. The unprecedented level of miniaturisation along with the high image quality produced by this device represents a radical new paradigm for minimally invasive imaging.

Detection of myocardial bridge by optical coherence tomography

Myocardial bridge (MB) is less commonly documented by angiography than autopsy. Optical coherence tomography (OCT) may be useful to detect angiographically undetectable MB. To investigate OCT characteristics of MB, 86 LAD vessels were imaged by OCT. MB was defined as presence of intermediate optical intensity, "fine" layer surrounding coronary artery by OCT. Frequency and characteristics of the angio-detectable and angio-undetectable but OCT-detectable MB were investigated. In a subset of patients with angio-detectable MB, cyclic changes in coronary arterial dimensions were analyzed. OCT detected MB in 44 of 86 (51%). Arc of the MB was significantly larger (334.8 ± 58.5° vs. 268.4 ± 92.1°, P = 0.008) and length was significantly longer (22.6 ± 11.7 mm vs. 14.5 ± 8.1 mm, P = 0.014) in angio-detectable MB than OCT-detectable but angio-undetectable MB. Both vessel (6.8 ± 1.5 to 5.3 ± 1.0 mm2, P = 0.035) and lumen area (4.4 ± 1.5 to 3.1 ± 0.7 mm2, P = 0.040) decreased significantly from diastole to systole. Adventitial (0.08 ± 0.03 to 0.08 ± 0.02 mm, P = 0.828) and intima + plaque thickness (0.12 ± 0.05 to 0.10 ± 0.03 mm, P = 0.398) did not change significantly during cardiac cycle. On the other hand, medial thickness increased significantly from diastole to systole (0.08 ± 0.03 to 0.12 ± 0.03 mm, P = 0.022). In conclusion, MB is frequently detected as intermediate intensity, fine layer by OCT. During systole, vessel and lumen size decrease with increased medial thickness. Therefore, we should be careful for OCT interpretation of the coronary arteries with MB.

Incidence and prognostic impact of the calcified nodule in coronary artery disease patients with end-stage renal disease on dialysis

Coronary artery calcification is frequently observed in coronary artery disease (CAD) patients with end-stage renal disease (ESRD). Calcified nodule (CN) is recognized as one of the vulnerable plaque characteristics responsible for acute coronary syndrome (ACS). Although CN is a cause of ACS in only 10%, its prevalence may be higher in elderly patients and/or ESRD. The aim of this study is to investigate incidence, clinical characteristics, and prognostic impact of CN in CAD patients with ESRD on dialysis. A total of 51 vessels from 49 CAD patients with ESRD on dialysis were enrolled in this study. CN was defined as a high-backscattering mass protruding into the lumen with a strong signal attenuation and an irregular surface by optical coherence tomography. Incidence, clinical characteristics and prognosis of patients with CN were studied. Major adverse cardiac events (MACE) were defined as a composite of all-cause death, non-fatal myocardial infarction, target vessel revascularization (TVR) and stroke. CNs were observed in 30 vessels from 29 patients (59.2%). Duration of dialysis was significantly longer in CN group than in non-CN group (P = 0.03). Overall, all-cause death, cardiac death, TVR and MACE occurred in 7 (14.3%), 3 (6.1%), 11 (22.4%) and 16 (32.7%) patients during follow-up (median 826 days), respectively. Kaplan-Meier survival analysis revealed that MACE-free survival was significantly lower in patients with CN compared with those without CN (Log-rank, P = 0.036).In conclusion, CN was observed in about 60% of the CAD patients with ESRD and was associated with duration of dialysis and worse prognosis.

Influence of myocardial bridge on atherosclerotic plaque distribution and characteristics evaluated by near-infrared spectroscopy intravascular ultrasound

BACKGROUND

This study aims to clarify whether myocardial bridge (MB) could influence atherosclerotic plaque characteristics assessed using near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS) imaging.

METHODS

One hundred and sixteen patients who underwent percutaneous coronary intervention (PCI) using NIRS-IVUS imaging were included. MB was defined as an echo-lucent band surrounding left anterior descending artery (LAD). In MB patients, LAD was divided into three segments: proximal, MB, and distal segments. In non-MB patients, corresponding three segments were defined based on the average length of the above segments. Segmental maximum plaque burden and lipid content derived from NIRS-IVUS imaging in the section of maximum plaque burden were evaluated in each segment. Lipid content of atherosclerotic plaque was evaluated as lipid core burden index (LCBI) and maxLCBI_4mm. LCBI is the fraction of pixels indicating lipid within a region multiplied by 1000, and the maximum LCBI in any 4-mm region was defined as maxLCBI_4mm.

RESULTS

MB was identified in 42 patients. MB was not associated with maximum plaque burden in proximal segment. LCBI and maxLCBI_4mm were significantly lower in patients with MB than those without in proximal segment. Multivariable analysis demonstrated both MB and maximum plaque burden in proximal segment to be independent predictors of LCBI in proximal segment.

CONCLUSIONS

Lipid content of atherosclerotic plaque assessed by NIRS-IVUS imaging was significantly smaller in patients with MB than those without. MB could be considered as a predictor of lipid content of atherosclerotic plaque when assessed by NIRS-IVUS imaging.

Cardiovascular events and atherosclerosis in patients with type 2 diabetes and impaired glucose tolerance -What are the medical treatments to prevent cardiovascular events in such patients?

Type 2 diabetes mellitus (T2DM) and impaired glucose tolerance (IGT) significantly induce advanced coronary artery disease and systemic atherosclerosis. Thus, T2DM and IGT are traditional risk factors of cardiovascular disease (CVD). On the other hand, acute coronary syndrome is frequently caused by the rupture of coronary atherosclerotic plaques, which reduces patients' quality of life and may result in death. To date, many trials have sought to identify ways to determine the coronary plaque volume and its vulnerability, and many studies have demonstrated that some specific antihyperglycemic agents may prevent coronary or carotid plaque progression, decrease plaque volume, induce plaque stability, and improve clinical outcomes in patients with T2DM and IGT. This article reviews i) the association between coronary or carotid plaques and abnormal glucose tolerance, including T2DM; and ii) the effects of oral antihyperglycemic drugs to improve clinical outcomes and stabilize atherosclerotic plaques in patients with T2DM and IGT.

Relation of glucose variability to vulnerable plaque formation in patients with coronary artery disease

BACKGROUND

Although glucose variability (GV) is reportedly associated with coronary plaque vulnerability, namely lipid-rich plaque, details are not fully understood. The aim of this study was to evaluate relations of GV after discharge to vulnerable plaque formation assessed by near-infrared spectroscopy intravascular ultrasound (NIRS-IVUS) in patients with and without diabetes.

METHODS

A total of 40 patients undergoing percutaneous coronary intervention under NIRS-IVUS guidance were included, among whom 13 (33%) had diabetes and 20 (50%) presented with acute myocardial infarction (MI). GV was evaluated by a flush glucose monitoring system, primarily with mean amplitude of glycemic excursion (MAGE). Lipid-rich plaque was assessed by maximum lipid core burden index in 4 mm (maxLCBI_4mm) in the target lesion using NIRS-IVUS.

RESULTS

Mean MAGE and maxLCBI_4mm were 69.7 ± 25.6 mg/dl and 508.0 ± 294.9. Intra-day GV was not significantly associated with maxLCBI_4mm in the entire study population, while MAGE was correlated with maxLCBI_4mm in non-diabetic patients (r = 0.46, p = 0.02). In patients with and without acute MI presentation, no significant relations were found between MAGE and maxLCBI_4mm.

CONCLUSION

GV was associated with lipid core plaque formation, especially in non-diabetic patients.

Volume-Outcome Relationships for Percutaneous Coronary Intervention in Acute Myocardial Infarction

Background Lower primary percutaneous coronary intervention (PCI) volume is known to be associated with worse outcomes in patients with acute myocardial infarction (MI) at hospital level. The present study aimed to evaluate the relations of primary, elective, and total PCI volume and primary/total PCI volume ratio per hospital to in-hospital mortality in patients with acute MI undergoing primary PCI. Methods and Results Using a large nationwide administrative database, we included a total of 83 076 patients from 154 hospitals in Japan undergoing PCI for either acute MI or elective cases. Relations of annual procedural volumes for primary, elective, and total PCI to in-hospital mortality after acute MI at hospital level were evaluated. The ratio of primary to total PCI volume per hospital was also assessed. The primary end point was the ratio of observed to predicted mortality. Of 83 076 patients, 26 913 (32.4%) underwent primary PCI for acute MI, among whom 1561 (5.8%) died during hospitalization. Overall, observed in-hospital mortality after acute MI and observed/predicted mortality ratio were higher in hospitals with lower primary, elective, and total PCI volumes. Observed/predicted in-hospital mortality ratio was higher in hospitals with low primary/total PCI volume ratio, even in those with high total PCI volume. Conclusions Primary, elective, and total PCI volume at hospitals were inversely associated with in-hospital mortality in patients with acute MI undergoing primary PCI. Lower ratio of primary to total PCI volume were related to higher in-hospital mortality, suggesting primary/total PCI volume ratio as an institutional indicator of quality of care for acute MI.

Discrepancy between plaque vulnerability and functional severity of angiographically intermediate coronary artery lesions

This study sought to investigate the relationship between physiological severity and plaque vulnerability of intermediate coronary artery stenoses as assessed by fractional flow reserve (FFR) and near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS). We included vessels where both FFR and NIRS-IVUS were performed. A positive FFR was defined as FFR ≤ 0.80. Lipid core burden index of the entire target vessel (TV-LCBI), maximum LCBI in 4 mm (maxLCBI_4mm), and maximum plaque burden (PB) were evaluated using NIRS-IVUS. A vulnerable plaque was defined as a lipid-rich plaque (maxLCBI4_mm ≥ 400) with large PB (≥ 70%). A total of 59 vessels of 45 patients were included. Median FFR value was 0.75 [interquartile 0.72, 0.82]. An FFR value of ≤ 0.80 was observed in 42 vessels (71%). TV-LCBI (correlation coefficient [CC] = - 0.331, p = 0.011), lesion length (CC = - 0.350, p = 0.007), and PB (CC = - 0.230, p = 0.080) negatively correlated with FFR value, while maxLCBI_4mm did not (CC = - 0.156, p = 0.24). The prevalence of vulnerable plaques (26.2% vs. 29.4%, p > 0.99) and mean TV-LCBI, maxLCBI_4mm, and PB values were not significantly different between the vessels with FFR ≤ 0.80 and those with FFR > 0.80. In multivariable logistic models, diabetes mellitus (p = 0.003) and hemoglobin A1c (p = 0.012) were associated with the presence of a vulnerable plaque. In conclusion, the results of the present study suggested that FFR may reflect total lipid burden but not necessarily plaque vulnerability. In patients with coronary artery disease and a high likelihood of rapid atherosclerosis progression, such as diabetes mellitus patients, assessing plaque vulnerability in addition to the functional severity of coronary artery lesions may help stratify better the risk of future events.

Current and Future Applications of Artificial Intelligence in Coronary Artery Disease

Cardiovascular diseases (CVDs) carry significant morbidity and mortality and are associated with substantial economic burden on healthcare systems around the world. Coronary artery disease, as one disease entity under the CVDs umbrella, had a prevalence of 7.2% among adults in the United States and incurred a financial burden of 360 billion US dollars in the years 2016–2017. The introduction of artificial intelligence (AI) and machine learning over the last two decades has unlocked new dimensions in the field of cardiovascular medicine. From automatic interpretations of heart rhythm disorders via smartwatches, to assisting in complex decision-making, AI has quickly expanded its realms in medicine and has demonstrated itself as a promising tool in helping clinicians guide treatment decisions. Understanding complex genetic interactions and developing clinical risk prediction models, advanced cardiac imaging, and improving mortality outcomes are just a few areas where AI has been applied in the domain of coronary artery disease. Through this review, we sought to summarize the advances in AI relating to coronary artery disease, current limitations, and future perspectives.

Derivation of a Novel Scoring System Predicting High Platelet Reactivity on Prasugrel in Patients with Coronary Artery Disease

AIMS

High platelet reactivity (HPR) has been associated with an increased risk of thrombotic events in patients undergoing percutaneous coronary intervention. HPR has been well examined in patients treated with clopidogrel; however, HPR on prasugrel is poorly investigated.

METHODS

Four prospective studies were pooled, in which platelet reactivity on prasugrel was measured using VerifyNow assay; genotyping of CYP2C19 was also performed. Factors associated with HPR on prasugrel were identified using multivariable analysis to develop a risk prediction model.

RESULTS

In total, 180 patients were examined in this study, of whom 51 (28%) had HPR on prasugrel. The multivariable analysis indicated that hypertension, diabetes, hemodialysis, and the number of CYP2C19 loss-of-function (LOF) alleles are significant factors for HPR on prasugrel. These four factors were then incorporated to develop the HHD-GENE score. The receiver operating characteristic curve analysis showed that the HHD-GENE score predicted HPR on prasugrel (area under the curve (AUC) 0.74, best cutoff value 5, p＜0.001). With the best cutoff value, patients with the HHD-GENE score ≥ 5 had a significantly increased risk of HPR on prasugrel than their counterpart (50% vs. 18%, p＜0.001).

CONCLUSIONS

The HHD-GENE score consisting of hypertension, diabetes, hemodialysis, and CYP2C19 LOF alleles may be useful in identifying patients on prasugrel who are at high risk for HPR. External validation is needed to define the clinical utility of this novel scoring system.

Extent of lipid core plaque in patients with Achilles tendon xanthoma undergoing percutaneous coronary intervention for coronary artery disease

BACKGROUND

It has been reported that Achilles tendon xanthoma (ATX), being one of the important diagnostic criteria for familial hypercholesterolemia, is independently associated with the severity of coronary artery disease (CAD). The aim of this study was to investigate plaque vulnerability in CAD patients with ATX.

METHODS

Patients with CAD who underwent percutaneous coronary intervention (PCI) with near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS) guidance were enrolled. Soft X-ray radiography of the Achilles tendon was performed, and a maximum thickness of 9 mm or more was regarded as ATX. Using NIRS-IVUS, the degree of lipid core plaque (LCP) was evaluated by calculating the maximum value of lipid core burden index (LCBI) for any of the 4-mm segments (maxLCBI_4mm) in the target lesion and non-target vessel.

RESULTS

In a total of 156 patients, 14 patients (9.0%) had ATX. MaxLCBI_4mm in the ATX group was significantly greater in the target lesion (p<0.001) and in the non-target vessel (p=0.032) compared to the non-ATX group. When patients were divided into tertiles according to Achilles tendon thickness, maxLCBI_4mm was progressively increased in favor of thickness, although there was only a tendency in the target lesion (p=0.062), and no statistical significance in the non-target vessel (p=0.189). Multiple linear regression analysis determined ATX as an independent predictor for maxLCBI_4mm in the target lesion and non-target vessel.

CONCLUSIONS

ATX was associated with the degree of LCP in CAD patients requiring PCI. High-risk patients with lipid-rich vulnerable plaque can possibly be detected by evaluating Achilles tendon thickness.

Impact of Active and Historical Cancer on Short- and Long-Term Outcomes in Patients With Acute Myocardial Infarction

Patients with cancer have an increased risk of cardiovascular events including myocardial infarction (MI) and vice versa, and are at high risks of ischemic and bleeding events after MI. However, short- and long-term clinical outcomes in patients with acute MI based on cancer status are not fully understood. This bi-center registry included 903 patients with acute MI undergoing primary percutaneous coronary intervention in a contemporary setting. Patients were divided into active cancer, a history of cancer, and no cancer according to the status of malignancy. Major adverse cardiovascular events (MACE), a composite of all-cause death, recurrent MI, and stroke, and major bleedings were evaluated. Of 903 patients, 49 (5.4%) and 65 (7.2%) had active cancer and a history of cancer, and 87 (9.6%) patients died during the hospitalization. In-hospital MACE was not significantly different among the 3 groups (16.3% vs 10.8% vs 10.9%, p = 0.48), whereas the rate of major bleeding events during the index hospitalization was significantly higher in patients with active cancer than their counterpart (20.4% vs 6.2% vs 5.8%, p = 0.002). After discharge, patients with active cancer had an increased risk of MACE and major bleedings compared with those with a history of cancer and no cancer during the mean follow-up period of 853 days. In conclusions, active cancer rather than a history of cancer and no cancer had significant impact on in-hospital bleeding events, and MACE and major bleedings after discharge in patients with acute MI undergoing primary percutaneous coronary intervention.

Utility of near-infrared spectroscopy to detect the extent of lipid core plaque leading to periprocedural myocardial infarction

OBJECTIVES

The aim of this study was to investigate whether lipid core plaque (LCP) in the entire stented segment detected by near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS) could predict procedural myocardial infarction (PMI) in patients undergoing percutaneous coronary artery intervention (PCI).

BACKGROUND

NIRS-IVUS can identify LCP, described as high lipid core burden index (LCBI). Previously, the highest LCBI contained only in the 4-mm segment (maxLCBI_4mm ) was reported to predict PMI.

METHODS

Patients who underwent NIRS-IVUS examination during PCI for coronary artery disease at Chiba University Hospital were included. The extent of LCP in the stented segment derived from NIRS-IVUS analysis was presented as LCBI, maxLCBI_4mm , and LCP area index (LAI), reflecting the total amount of LCP in the entire stented segment calculated as LCBI×lesion length. PMI was defined as an elevation of creatine kinase MB > 3 times upper reference level (URL), and periprocedural myocardial injury (PMInj) was defined as an elevation of troponin I>5 times URL within 12 to 24 h after PCI.

RESULTS

Out of 141 enrolled patients, PMI occurred in 20 (14.2%) and PMInj occurred in 62 (44.0%) patients. Receiver-operating characteristic curve analysis revealed LAI was the strongest predictor for both PMI and PMInj (area under curve 0.771, p < 0.001, and 0.717, p < 0.001, respectively). Multiple logistic regression analysis determined high LAI value as the independent predictor of both PMI and PMInj.

CONCLUSIONS

Greater extent of LCP in the entire stented segment detected by NIRS-IVUS was significantly associated with PMI as well as PMInj in patients undergoing PCI.

Subintimal Versus Intraluminal Approach for Femoropopliteal Chronic Total Occlusions Treated With Intravascular Ultrasound Guidance

Background

The subintimal approach (SA) is widely used in endovascular therapy for femoropopliteal chronic total occlusion lesions. However, when compared with the intraluminal approach (IA), the safety and efficacy of SA in real‐world practice are not well characterized. Furthermore, there is a paucity of data on the clinical impact of subintimal and intraluminal wire passage (SWP and IWP, respectively) assessed by intravascular ultrasound.

Methods and Results

From the IVORY (Intravascular Ultrasound‐Supported Endovascular Therapy in Superficial Femoral Artery) registry, this study included 500 patients undergoing endovascular therapy for femoropopliteal chronic total occlusion lesions (SA, n=67; IA, n=433; and SWP, n=186; IWP, n=314). The primary end point was the cumulative 1‐year incidence of restenosis. The rate of perioperative complications was also assessed. Propensity score matching analysis was performed to adjust for the intergroup differences. After propensity score matching, the final study population consisted of 59 pairs (SA, n=59; IA, n=348) and 170 pairs (SWP, n=170; IWP, n=293), respectively. Cumulative 1‐year incidence of restenosis was comparable between the SA and IA groups (41.0% versus 43.4%, P=0.40). No significant difference in 1‐year restenosis rate between the SWP and IWP groups was observed (48.2% versus 40.8%, P=0.40), although the SWP group tended to be a higher rate of perioperative complications than the IWP group (8.2% versus 4.1%, P=0.07).

Conclusions

At 1 year, both SA and IA showed acceptable results for femoropopliteal chronic total occlusion lesions. Cumulative 1‐year incidence of restenosis was not significantly different between SWP and IWP, whereas perioperative complications occurred more frequently in SWP than in IWP.

Registration

URL: https://www.umin.ac.jp; Unique identifier: UMIN000020472.

Molecular Imaging-Guided Sonodynamic Therapy

Low-intensity ultrasound-triggered sonodynamic therapy (SDT) is a promising noninvasive therapeutic modality due to its strong tissue penetration ability. In recent years, with the development of nanotechnology, nanoparticle-based sonosensitizer-mediated SDT has been widely investigated. With the increasing demand for precise and personalized treatment, abundant novel sonosensitizers with imaging capabilities have been developed for determining the optimal therapeutic window, thus significantly enhancing treatment efficacy. In this review, we focus on the molecular imaging-guided SDT. The prevalent mechanisms of SDT are discussed, including ultrasonic cavitation, sonoluminescence, reactive oxygen species, and mechanical damage. In addition, we introduce the major molecular imaging techniques and the design principles based on nanoparticles to achieve efficient imaging. Furthermore, the imaging-guided SDT for the treatment of cancer, bacterial infections, and vascular diseases is summarized. The ultimate goal is to design more effective imaging-guided SDT modalities and provide novel ideas for clinical translation of SDT.

Impact of Serum Uric Acid Level on Systemic Endothelial Dysfunction in Patients with a Broad Spectrum of Ischemic Heart Disease

Previous studies indicated that serum uric acid (SUA) level is a marker of endothelial function in subsets of ischemic heart disease (IHD). In the present study, we aimed to evaluate the relation between the SUA level and endothelial function in patients with a broad spectrum of IHD, including obstructive coronary artery disease (CAD) and ischemia with no obstructive CAD (INOCA). Three prospective studies and one retrospective study were pooled, in which the SUA level was measured, and systemic endothelial function was assessed using the reactive hyperemia index (RHI). The primary endpoint of the present study was a correlation of the SUA level with RHI. A total of 181 patients with a broad spectrum of IHD were included, among whom, 46 (25%) had acute coronary syndrome presentation and 15 (8%) had INOCA. Overall, the SUA level was negatively correlated with the RHI (r = −0.22, p = 0.003). Multivariable analysis identified the SUA level and INOCA as significant factors associated with RHI values. In conclusion, in patients with a broad spectrum of IHD, including obstructive epicardial CAD (chronic and acute coronary syndromes) and INOCA, the SUA level was significantly and negatively correlated with systemic endothelial function assessed with the RHI. INOCA, rather than obstructive CAD, was more associated with endothelial dysfunction.

Impact of PARIS and CREDO-Kyoto Thrombotic and Bleeding Risk Scores on Clinical Outcomes in Patients With Acute Myocardial Infarction

BACKGROUND

The PARIS and CREDO-Kyoto risk scores were developed to identify patients at risks of thrombotic and bleeding events individually after percutaneous coronary intervention (PCI). However, these scores have not been well validated in different cohorts.Methods and Results:This 2-center registry enrolled 905 patients with acute myocardial infarction (MI) undergoing primary PCI. Patients were divided into 3 groups according to the PARIS and CREDO-Kyoto thrombotic and bleeding risk scores. The study endpoints included ischemic (cardiovascular death, recurrent MI, and ischemic stroke) and major bleeding events. Of 905 patients, 230 (25%) and 219 (24%) had high thrombotic and bleeding risks, respectively, with the PARIS scores, compared with 78 (9%) and 50 (6%) patients, respectively, with the CREDO-Kyoto scores. According to the 2 scores, >50% of patients with high bleeding risk had concomitant high thrombotic risk. During the mean follow-up period of 714 days, 163 (18.0%) and 95 (10.5%) patients experienced ischemic and bleeding events, respectively. Both PARIS and CREDO-Kyoto scores were significantly associated with ischemic and bleeding events after primary PCI. For ischemic events, the CREDO-Kyoto rather than PARIS thrombotic risk score had better diagnostic ability.

CONCLUSIONS

In the present Japanese cohort of acute MI patients undergoing contemporary primary PCI, the PARIS and CREDO-Kyoto thrombotic and bleeding risk scores were discriminative for predicting ischemic and bleeding events.

Impact of glycemic variability on coronary and peripheral endothelial dysfunction in patients with coronary artery disease

BACKGROUND

Previous studies have reported that glucose variability leads to endothelial dysfunction and progression of coronary atherosclerosis. However, few studies have directly evaluated the relation between glucose variability and coronary endothelial function in patients with coronary artery disease (CAD).

METHODS

A total of 38 patients with chronic CAD and a history of coronary drug-eluting stent implantation were enroled. Coronary endothelial function was evaluated by measuring the coronary vasoreactivity using quantitative coronary angiography in the segment distal to implanted stent in response to intracoronary acetylcholine (ACh) infusion (10-7 mol/l). Peripheral endothelial function was also assessed with reactive hyperemia index (RHI). The mean amplitude of glycemic excursion (MAGE) was calculated as a primary metric of glucose variability using a flash glucose monitoring system.

RESULTS

Of 38 patients, 17 (45%) had diabetes mellitus. The mean levels of glycated hemoglobin, MAGE, and RHI were 6.3 ± 0.8%, 71.4 ± 29.8 mg/dl, and 1.85 ± 0.63. In the distal segment to coronary stent, lumen diameter was constricted by 0.6 ± 7.3% in response to intracoronary ACh infusion compared to that at baseline. While peripheral endothelial function assessed with RHI was not significantly associated with MAGE (r = -0.16, p = 0.35), coronary endothelial function was correlated with MAGE (r = -0.38, p = 0.02).

CONCLUSION

Greater glucose variability was significantly associated with coronary rather than peripheral endothelial dysfunction in patients with CAD, suggesting an impact of glucose variability on coronary atherosclerosis.

Differential Impact of Clinical and Genetic Factors on High Platelet Reactivity in Patients with Coronary Artery Disease Treated with Clopidogrel and Prasugrel

AIM

High platelet reactivity (HPR) is associated with increased risks of thrombotic events in patients with coronary artery disease. The recently developed ABCD-GENE score identified five clinical and genetic factors (age, body mass index, chronic kidney disease, diabetes, and the CYP2C19 loss-of-function allele) for HPR, although the significance of various stages of each factor is unclear.

METHODS

Four prospective studies were pooled, in which platelet reactivity was measured using the VerifyNow assay with clopidogrel and prasugrel; genotyping of CYP2C19 was also performed. Each component of the ABCD-GENE score was divided into three subcategories. VerifyNow P2Y12 reactivity units ＞208 were defined as HPR.

RESULTS

A total of 184 patients were included, of which 111 (60%) and 51 (28%) had HPR with clopidogrel and prasugrel. Chronic kidney disease had an impact on HPR on both clopidogrel and prasugrel, whereas the impact of diabetes was more evident in patients treated with prasugrel. Although the number of CYP2C19 loss-of-function alleles was clearly associated with a likelihood of HPR with clopidogrel, P2Y12 reactivity units with prasugrel treatment were also significantly and progressively higher in patients with more CYP2C19 loss-of-function alleles.

CONCLUSIONS

Clinical and genetic factors had a differential effect on a P2Y12 inhibitor reactivity with clopidogrel and prasugrel in patients with coronary artery disease. The severity of the factors also had a different impact on HPR.

Factors that predict ventricular arrhythmias in the late phase after acute myocardial infarction

Aims

Little is known regarding factors that predict the occurrence of lethal ventricular arrhythmias (VAs) occurring after acute myocardial infarction (AMI). This observational cohort study aimed to identify factors that predicted lethal VAs during the late phase after AMI in patients with reduced left ventricular ejection fraction (LVEF).

Methods and results

Data were collected from our AMI database regarding consecutive patients with an LVEF of ≤40% after AMI (January 2012 to July 2018). The ‘late phase’ was defined as ≥7 days after AMI onset, and the primary endpoint was defined as lethal VAs in the late phase. The study included 136 patients (82% men; mean age: 66 ± 13 years). The average LVEF at admission was 32.7 ± 8.2%. During a mean follow‐up period of 20.7 months, 14 patients (10%) experienced lethal VAs, including ventricular fibrillation (n = 8) and sustained ventricular tachycardia (n = 10). Univariate analyses revealed that lethal VAs were predicted by age and LVEF at admission. Receiver operating characteristic curve analysis indicated that the optimal cut‐off value was 23% for using the LVEF at admission to predict the primary endpoint (area under the curve: 0.77, P < 0.0001). Multivariable analysis also demonstrated that LVEF at admission was an independent predictor of the primary endpoint (risk ratio = 7.12, P = 0.001).

Conclusions

Lethal VAs in the late phase are common in patients with AMI, and reduced LVEF and cardiac function at admission play a significant role in the risk stratification for future lethal VAs in this population.

Automated classification of coronary atherosclerotic plaque in optical frequency domain imaging based on deep learning

BACKGROUND AND AIMS

We developed a deep learning (DL) model for automated atherosclerotic plaque categorization using optical frequency domain imaging (OFDI) and performed quantitative and visual evaluations.

METHODS

A total of 1103 histological cross-sections from 45 autopsy hearts were examined to compare the ex vivo OFDI scans. The images were segmented and annotated considering four histological categories: pathological intimal thickening (PIT), fibrous cap atheroma (FA), fibrocalcific plaque (FC), and healed erosion/rupture (HER). The DL model was developed based on pyramid scene parsing network (PSPNet). Given an input image, a convolutional neural network (ResNet50) was used as an encoder to generate feature maps of the last convolutional layer.

RESULTS

For the quantitative evaluation, the mean F-score and IoU values, which are used to evaluate how close the predicted results are to the ground truth, were used. The validation and test dataset had F-score and IoU values of 0.63, 0.49, and 0.66, 0.52, respectively. For the section-level diagnostic accuracy, the areas under the receiver-operating characteristic curve produced by the DL model for FC, PIT, FA, and HER were 0.91, 0.85, 0.86, and 0.86, respectively, and were comparable to those of an expert observer.

CONCLUSIONS

DL semantic segmentation of coronary plaques in OFDI images was used as a tool to automatically categorize atherosclerotic plaques using histological findings as the gold standard. The proposed method can support interventional cardiologists in understanding histological properties of plaques.

Impact of CADILLAC and GRACE risk scores on short- and long-term clinical outcomes in patients with acute myocardial infarction

BACKGROUND

Recent guidelines recommend risk stratification using objective scoring systems in patients with acute coronary syndrome. In this context, the CADILLAC (Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications) and GRACE (Global Registry of Acute Coronary Events) risk scores were both originally established to predict short-term mortality. However, their impact on short- and long-term clinical outcomes in a contemporary cohort of patients with acute myocardial infarction (MI) is unclear.

METHODS

This bi-center registry included 809 patients with acute MI undergoing primary percutaneous coronary intervention. Patients were divided into three groups according to the pre-defined thresholds and tertiles of the CADILLAC and GRACE scores. The study endpoints included all-cause death and major adverse cardiovascular events (MACE) during the index hospitalization and after discharge.

RESULTS

Of 809 patients, 323 (39.9%) and 255 (31.5%) had high CADILLAC and GRACE risk scores. During the index hospitalization, 61 (7.5%) patients died and 262 (32.4%) had MACE. Both CADILLAC and GRACE risk scores were associated with in-hospital mortality and MACE rates. After discharge, out of 683 patients with available follow-up information who survived to discharge, 42 (6.1%) died and 123 (18.0%) had MACE during the median follow-up period of 632 days. Significantly higher incidence of MACE in higher CADILLAC and GRACE risk scores was observed in a stepwise manner.

CONCLUSION

Both CADILLAC and GRACE risk scores were predictive for short- and long-term mortality and MACE rates in a contemporary cohort of acute MI patients undergoing primary percutaneous coronary intervention.

Ultrasound Methods in the Evaluation of Atherosclerosis: From Pathophysiology to Clinic

Atherosclerosis is a key pathological process that causes a plethora of pathologies, including coronary artery disease, peripheral artery disease, and ischemic stroke. The silent progression of the atherosclerotic disease prompts for new surveillance tools that can visualize, characterize, and provide a risk evaluation of the atherosclerotic plaque. Conventional ultrasound methods—bright (B)-mode US plus Doppler mode—provide a rapid, cost-efficient way to visualize an established plaque and give a rapid risk stratification of the patient through the Gray–Weale standardization—echolucent plaques with ≥50% stenosis have a significantly greater risk of ipsilateral stroke. Although rather disputed, the measurement of carotid intima-media thickness (C-IMT) may prove useful in identifying subclinical atherosclerosis. In addition, contrast-enhanced ultrasonography (CEUS) allows for a better image resolution and the visualization and quantification of plaque neovascularization, which has been correlated with future cardiovascular events. Newly emerging elastography techniques such as strain elastography and shear-wave elastography add a new dimension to this evaluation—the biomechanics of the arterial wall, which is altered in atherosclerosis. The invasive counterpart, intravascular ultrasound (IVUS), enables an individualized assessment of the anti-atherosclerotic therapies, as well as a direct risk assessment of these lesions through virtual histology IVUS.

Clinical implications and debates on the ISCHEMIA trial

The ISCHEMIA was eagerly awaited study in the field of ischemic heart disease. Following the presentation and publication of ISCHEMIA, multiple opinions and viewpoints get complicated. The ongoing debates have been including the relevance of coronary revascularization, non-invasive diagnostic methods, and invasive ischemic testing in patients with stable ischemic heart disease (SIHD). Prior to ISCHEMIA, observational studies indicated the potential of coronary revascularization for improving clinical outcomes, while the randomized COURAGE trial did not support the plausible concept. Although the FAME 2 trial implied the superiority of percutaneous coronary intervention over medical therapy alone, the clinical relevance of coronary revascularization to improve outcomes and quality of life has been questioned. As a consequence, the ISCHEMIA trial did not demonstrate clear benefits in reducing clinical events but showed antianginal effects of revascularization. This landmark trial also suggested the difficulties of non-invasive ischemia testing rather than computed tomography angiography. Despite the complex results, the ISCHEMIA trial may simplify the clinical indications of coronary revascularization in patients with SIHD. Future publications from the ISCHEMIA trial and debates on the results will sharpen our thinking and understanding.

Comparison of quantitative measurements between two different intravascular ultrasound catheters and consoles: in vitro and in vivo studies

Previous studies suggested possible discordant quantitative measurements between different IVUS catheters and/or systems. The purpose of this study was to assess compatibility of two different IVUS catheters and consoles for quantitative measurements of coronary arteries. (1). In vitro study: IVUS imaging was performed in a concentric cylindrical phantom with 6 sections of known, cross-sectional diameter ranging from 3.0 to 8.0 mm. The lumen diameter (LD) and lumen cross-sectional area (LA) were measured and compared. To compare between 2 different IVUS consoles, IVUS images were obtained using a single IVUS catheter (catheter 1) connected to 2 different IVUS consoles (console 1 and 2). To compare between 2 different IVUS catheters, IVUS imaging was obtained using 2 different IVUS catheters (catheter 1 and 2) connected to a single IVUS console (console 2). (2). In vivo study: IVUS imaging was performed in 40 stented coronary arterial segments from 40 patients. The maximal stent diameter (Max SD), minimal stent diameter (minSD), and stent area (SA) were measured at both distal and proximal stent edges and compared between the two IVUS consoles (console 1 and 2) connected to a single IVUS catheter (catheter 1) (n = 20). IVUS imaging was also performed to compare between catheter 1 and 2 connected to IVUS console 2 (n = 20). Both in vitro and in vivo studies showed good correlation between the two IVUS consoles as well as two IVUS catheters. In conclusion, two IVUS catheters and consoles provide comparable IVUS measures both in vitro and in vivo.

Insufficient recovery of fractional flow reserve even after optimal implantation of drug-eluting stents: 3-year outcomes from the FUJI study

BACKGROUND

Adequate improvement in fractional flow reserve (FFR) is not necessarily achieved in some cases of drug-eluting stent (DES) implantation, even when imaging confirms successful placement. We hypothesized that post-stent FFR may be associated with advanced diffuse atherosclerotic condition. We explored the relationships between FFR values after DES implantation (post-stent FFR).

METHODS

A total of 218 patients were included in this prospective, multicenter study and were divided into two groups: adequate FFR group (post-stent FFR >0.80, n=176) and inadequate FFR group (post-stent FFR ≤0.80, n=42). The primary endpoint was a major adverse cardiovascular event (MACE) including cardiac death, non-fatal myocardial infarction (MI), unplanned coronary revascularization, and hospitalization for heart failure. The secondary endpoints were event rate of all-cause death, non-fatal MI, unplanned coronary revascularization, non-fatal stroke, and hospitalization for heart failure.

RESULTS

During follow-up of 31.4±8.7 months, 34 patients (16%) had cardiovascular events. Inadequate FFR group was significantly associated with higher risk of MACE (hazard ratio: 3.86; 95% confidence interval: 1.17-12.76, p=0.026; log-rank p=0.027). In particular, the incidence of unplanned coronary revascularization on non-target lesions was significantly higher in the inadequate FFR group (log-rank p=0.031).

CONCLUSIONS

Post-stent FFR ≤0.80 was associated with a high incidence of non-target lesion revascularization and could be a surrogate marker for advanced atherosclerotic condition in the vessels of the entire coronary artery.

Drug-eluting stent thrombosis: current and future perspectives

Over the past 40 years, the safety and efficacy of percutaneous coronary intervention has dramatically improved by overcoming several challenges. The introduction of drug-eluting stent (DES) in particular was a major breakthrough in interventional cardiology. Compared to bare-metal stents, first-generation DES (G1-DES) has dramatically reduced the rates of in-stent restenosis and subsequent target lesion revascularization. However, major safety concerns surrounding stent thrombosis (ST) emerged with G1-DES in clinical practice as a result of the high incidences of death, myocardial infarction, and repeat revascularization associated with ST. To overcome these limitations, second-generation DES (G2-DES) has been developed with an improved stent platform with thinner strut and biocompatible durable or biodegradable polymers. Indeed, G2-DES, when compared with G1-DES, has improved clinical outcomes by reducing the risk of late thrombotic events while maintaining anti-restenotic efficacy, whereas ST still occurs, even with the use of G2-DES. This review gives an overview of pathophysiology, risk factors, and outcomes of ST after DES implantation. Additionally, we discuss the management and prevention of ST.

Long-Term Clinical Outcomes After Filter Protection During Percutaneous Coronary Intervention in Patients With Attenuated Plaque - 1-Year Follow up of the VAMPIRE 3 (Vacuum Aspiration Thrombus Reemoval 3) Trial

BACKGROUND

Selective use of distal filter protection during percutaneous coronary intervention (PCI) for acute coronary syndromes (ACS) decreased the incidence of no-reflow phenomena and in-hospital serious adverse cardiac events compared with conventional PCI in patients with attenuated plaque ≥5 mm; however, its long-term clinical outcome remains unknown.Methods and Results:Patients who had ACS with attenuated plaque ≥5 mm were assigned to receive distal protection (DP) (n=98) or conventional treatment (CT) (n=96). The rate of major adverse cardiovascular events (MACE), a composite of death from any cause, non-fatal myocardial infarction, or target vessel revascularization (TVR) at 1 year, was the pre-specified secondary endpoint of the trial. MACE at 1 year occurred in 12 patients (12.2%) in the DP group and 3 patients (3.1%) in the CT group (P=0.029), which was driven by a higher risk of TVR (11 [11.2%] vs. 2 [2.1%], P=0.018). In patients treated with bare-metal stents (n=42), MACE occurred in 25.0% of the patients in the DP group and in none of the patients in the CT group (P=0.029), whereas in patients treated with drug-eluting stents (n=151), rates of MACE were similar in the groups (8.1% vs. 3.9%, P=0.32).

CONCLUSIONS

In ACS patients with attenuated plaque ≥5 mm, the 1-year rates of MACE were higher in the DP group than in the CT group. This effect might be mitigated by the use of drug-eluting stents.

Interobserver variability in assessments of atherosclerotic lesion type via optical frequency domain imaging

BACKGROUND

To date, there have been no data available regarding the diagnostic performance of optical frequency domain imaging (OFDI) for in vivo histological classification of atherosclerotic lesions. This study investigated whether OFDI can be used to diagnose and classify histological atherosclerotic lesions in the coronary artery by ex vivo histological examinations.

METHODS

Three-hundred-fifteen histological cross-sections from 21 autopsy hearts were matched with the OFDI images. Histological cross-sections were classified into six categories: adaptive intimal thickening (AIT), pathological intimal thickening (PIT), fibrous cap atheroma (FA), fibrocalcific plaque (FC), calcified nodule, and healed erosion/rupture. The five observers with different years of experience in the interpretation of OFDI provided a single diagnosis for the OFDI scans of each cross-section according to the aforementioned six histological categories. The diagnostic accuracy and interobserver variability of lesion types for each OFDI observer were determined using histology as the gold standard.

RESULTS

The overall agreement rates between OFDI and histopathologic diagnosis for OFDI observers 1-5 were 81%, 70%, 68%, 61%, and 50% (κ values of 0.75, 0.61, 0.58, 0.49, and 0.36), respectively. Although the diagnostic accuracy of OFDI for detecting AIT and FC was excellent for all five observers, the sensitivity, and positive predictive values of OFDI for detecting PIT and FA were low in proportion to years of experience.

CONCLUSION

The diagnostic accuracy of atherosclerotic tissue properties from OFDI scans correlated with the observers' years of experience, especially when lesions contained lipid components.

Greater coronary lipid core plaque assessed by near-infrared spectroscopy intravascular ultrasound in patients with elevated xanthine oxidoreductase: a mechanistic insight

Elevated serum uric acid level was reportedly associated with greater coronary lipid plaque. Xanthine oxidoreductase (XOR) is a rate-limiting enzyme in purine metabolism and believed to play an important role in coronary atherosclerosis. However, the relation of XOR to coronary lipid plaque and its mechanism are unclear. Patients with stable coronary artery disease undergoing elective percutaneous coronary intervention under near-infrared spectroscopy intravascular ultrasound (NIRS-IVUS) guidance were prospectively enrolled. They were divided into three groups according to serum XOR activities: low, normal, and high. Coronary lipid core plaques in non-target vessels were evaluated by NIRS-IVUS with lipid core burden index (LCBI) and a maximum LCBI in 4 mm (maxLCBI_4mm). Systemic endothelial function and inflammation were assessed with reactive hyperemia index (RHI) and high-sensitivity C-reactive protein, neutrophil-to-lymphocyte ratio, and platelet-to-lymphocyte ratio. Of 68 patients, 26, 31, and 11 were classified as low, normal, and high XOR activity groups. LCBI (474.4 ± 171.6 vs. 347.4 ± 181.6 vs. 294.0 ± 155.9, p = 0.04) and maxLCBI_4mm (102.1 ± 56.5 vs. 65.6 ± 48.5 vs. 55.6 ± 37.8, p = 0.04) were significantly higher in high XOR group than in normal and low XOR groups. Although RHI was significantly correlated with body mass index, diabetes, current smoking, and high-density lipoprotein cholesterol, no relation was found between XOR activity and RHI. There were also no relations between XOR activity and C-reactive protein, neutrophil-to-lymphocyte ratio, or platelet-to-lymphocyte ratio. In conclusion, elevated XOR activity was associated with greater coronary lipid core plaque in patients with stable coronary artery disease, without significant relations to systemic endothelial function and inflammation.

Impact of clinical presentations on lipid core plaque assessed by near-infrared spectroscopy intravascular ultrasound

Near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS) studies have demonstrated that lipid core plaque (LCP) is frequently observed in the culprit segment of myocardial infarction (MI). However, little is known about the impact of clinical presentations such as chronic coronary syndrome (CCS) and acute coronary syndrome (ACS) including unstable angina (UA), non ST-segment elevation MI (NSTEMI), and ST-segment elevation MI (STEMI) on LCP. The present prospective single-center registry included a total of 178 patients who underwent percutaneous coronary intervention under NIRS-IVUS guidance. Patients were divided into CCS and ACS groups, and ACS patients were further sub-divided into the 3 groups according to the clinical presentation. The primary endpoint was coronary LCP in the target lesion assessed by NIRS-IVUS with maximal lipid core burden index over any 4 mm segment (maxLCBI_4mm). The study population included 124 and 54 patients with CCS and ACS. MaxLCBI_4mm in the target lesion was significantly higher in the ACS group than in the CCS group (503 [284-672] vs. 406 [250-557], p = 0.046). Among ACS patients, MaxLCBI_4mm in the target lesion was also significantly different in those with UA (n = 18), NSTEMI (n = 21), and STEMI (n = 15) (288 [162-524] vs. 518 [358-745] vs. 646 [394-848], p = 0.021). In conclusion, LCP assessed by NIRS-IVUS, a surrogate of coronary plaque vulnerability, was significantly different according to the clinical presentations such as CCS, UA, NSTEMI, and STEMI.

Prediction of optimal debulking segments before rotational atherectomy based on pre-procedural intravascular ultrasound findings

This study evaluated whether intravascular ultrasound (IVUS) examination before rotational atherectomy (RA) can predict the optimal route of passage of the RA burr along the vessel. 30 patients with calcified lesions who underwent IVUS before and immediately after RA were enrolled. IVUS analyses were performed at the minimum lumen area (MLA) site and at 0.5 mm intervals. Each IVUS cross-section was divided into 4 quadrants around the center of the lumen, and pre- and post-RA IVUS cross-section images were merged. Of 1140 cross-sections, 498 (44%) contained debulked regions. When the guidewire and IVUS were located within the same quadrant, the debulked region were distributed within the same quadrant in 96% of cross-sections. The debulked region and the guidewire were distributed within the same quadrant in 81% and the debulked region and the IVUS in 72% of cross-sections, in case the guidewire and IVUS were located in different quadrants. When the guidewire and the IVUS was apart > 1.0 mm, the debulked regions were distributed within the same quadrant as the guidewire in 100% and the IVUS in 0% of cross-sections. The position of the guidewire rather than that of the IVUS catheter on pre-RA IVUS images could predict the course of the RA burr's passage, especially when the guidewire and IVUS catheter were located apart from each other.

Impact of myocardial bridge on late lumen enlargement in distal reference segments after recanalization of coronary chronic total occlusion

Successful recanalization of coronary chronic total occlusion (CTO) can induce subsequent positive vascular remodeling. Although myocardial bridge (MB) is known to alter endothelial function and wall shear stress, the impact of MB on late lumen enlargement in the distal segment is unclear. A total of 59 patients who underwent successful percutaneous coronary intervention (PCI) for CTO in the left anterior descending artery (LAD) under intravascular ultrasound (IVUS) guidance and follow-up angiography at 8-12 months were included. Gray-scale IVUS images were analyzed and MB was detected. Lumen diameter (LD) at distal reference at post-PCI was quantitatively compared with corresponding LD at follow-up coronary angiography to assess late lumen enlargement. MB on IVUS was detected in 17 patients (29%). The length from LAD ostium to the entry of CTO was shorter (11.7 ± 13.9 vs. 22.8 ± 13.4 mm, p = 0.006) and LD at distal reference at post-PCI was smaller (1.65 ± 0.54 vs. 1.97 ± 0.56 mm, p = 0.049) in patients with MB than those without. At the mean follow-up of 10.4 ± 2.4 months, LD at distal reference was significantly increased by 25% from baseline to follow-up in the overall population (1.88 ± 0.57 vs. 2.21 ± 0.41 mm, p < 0.001), with a greater increase in patients with MB compared to those without (46 ± 31% vs. 17 ± 29%, p < 0.001). Multivariable analysis indicated MB as an independent predictor of late lumen enlargement. In patients with MB on IVUS, CTO was located in more proximal segment of LAD than those without. Late lumen enlargement at follow-up was greater in patients with MB compared to the counterpart.

In-Hospital Blood Pressure Variability: A Novel Prognostic Marker of Renal Function Decline and Cardiovascular Events in Patients with Coronary Artery Disease

INTRODUCTION

Several measures of blood pressure (BP) variability have been associated with kidney disease and cardiovascular events. Although BP is routinely measured during hospitalization in daily practice, the prognostic impact of in-hospital BP and its variability are uncertain.

METHODS

A total of 226 participants who underwent elective percutaneous coronary intervention (PCI) for stable coronary artery disease (CAD) were included. BP was measured by trained nurses during the 4-day hospitalization for PCI. BP variability was assessed by standard deviation (SD) and coefficient variation of systolic BP. Estimated glomerular filtration rate (eGFR) was calculated at baseline and follow-up (≥6 months). The cardiovascular end point was defined as a composite of cardiovascular death, acute coronary syndrome, stroke, heart failure hospitalization, and any coronary revascularization.

RESULTS

In-hospital BP was measured 9.5 ± 0.8 times. During a median follow-up period of 1.7 years, mean eGFR change was -1.7 mL/min/1.73 m2 per year, and 35 (15.5%) participants met the cardiovascular end point. Mean systolic BP and SD were negatively correlated with eGFR change. In the receiver operating characteristic curve analysis, SD of systolic BP predicted the cardiovascular end point (AUC 0.63, best cutoff value 14.2 mm Hg, p = 0.003). Kaplan-Meier analysis demonstrated a significantly higher incidence of the cardiovascular end point in patients with SD of systolic BP ≥14.2 mm Hg compared to their counterpart (p = 0.003). A multivariable analysis showed SD of systolic BP as an independent predictor for the cardiovascular end point. When assessed with coefficient variation, BP variability was similarly related to eGFR change and clinical outcomes.

CONCLUSION

Greater in-hospital BP variability was associated with renal function decline and cardiovascular events in patients with stable CAD.

Fundamentals and role of intravascular ultrasound in percutaneous coronary intervention

Intravascular ultrasound (IVUS) is a catheter-based invasive imaging modality that has become an essential adjunctive tool to percutaneous coronary intervention (PCI) over the past 20 years. Clinical applications of IVUS in PCI include assessment of lesion severity, characterizing plaque morphology, optimization of acute stent results and clarification of mechanisms of stent failure. Numerous meta-analyses of large observational and randomized studies support the role of IVUS-guided PCI in reducing short and long-term adverse outcomes, including mortality and stent failure, particularly in patients receiving drug-eluting stents (DESs) and in complex lesion subsets. The current review provides a summary of the fundamental aspects and current clinical roles of IVUS in coronary intervention.

Trajectory of renal function change and kidney injury after percutaneous coronary intervention in patients with stable coronary artery disease

Acute kidney injury usually assessed within 48 h after percutaneous coronary intervention (PCI) is associated with poor clinical outcomes, and persistent kidney damage is also strongly related to long-term mortality. However, little is known about longitudinal renal function change from a very early period to long-term follow-up after PCI. A total of 327 patients with stable coronary artery disease underwent elective PCI. Renal function was assessed with serum creatinine levels and estimated glomerular filtration rate (eGFR) at baseline, 1 day after PCI, at 1 year and at the latest follow-up. Kidney injury was defined as an increase in creatinine levels ≥ 0.3 mg/dl or ≥ 50% from baseline at each timepoint. Major adverse cardiovascular events (MACE) was defined as a composite of death, myocardial infarction, and stroke. eGFR was significantly increased 1 day after PCI, while it was progressively decreased at 1-year and long-term follow-up (median 28 months). Overall, eGFR was declined by - 2.3 ml/min/1.73 m² per year. Only one (0.3%) patient developed kidney injury 1 day after PCI, whereas kidney injury at 1-year and long-term follow-up was observed in 15 (4.6%) and 27 (8.3%). During the follow-up period, 23 (7.0%) patients had MACE. The incidence of subsequent MACE was significantly higher in patients with kidney injury at 1 year than those without. In conclusion, kidney injury within 24 h after elective PCI was rarely observed. eGFR was progressively decreased over time, and mid-term kidney injury at 1 year was associated with future MACE.

Update on Antithrombotic Therapy after Percutaneous Coronary Intervention

Percutaneous coronary intervention (PCI) has become a standard-of-care procedure in the setting of angina or acute coronary syndrome. Antithrombotic therapy is the cornerstone of pharmacological treatment aimed at preventing ischemic events following PCI. Dual antiplatelet therapy as the combination of aspirin and P2Y₁₂ inhibitor has been proven to decrease stent-related thrombotic risks. However, the optimal duration of dual antiplatelet therapy, an appropriate P2Y₁₂ inhibitor, and the choice of aspirin versus P2Y₁₂ inhibitor as single antiplatelet therapy remain controversial. Furthermore, the combined use of oral anticoagulation in addition to antiplatelet therapy is a complex issue in clinical practice, such as in patients with atrial fibrillation. The key challenge concerning the optimal antithrombotic regimen is ensuring a balance between protection against thrombotic events and against excessive increases in bleeding risk. In this review article, we summarize the current evidence concerning antithrombotic therapy in patients with coronary artery disease undergoing PCI.