Burr entrapment in a percutaneous coronary intervention during rotational atherectomy: An experience with 3195 cases.

OBJECTIVES: Burr entrapment is a potentially life-threatening complication of rotational atherectomy (RA). However, owing to its infrequency, there have been no major reports on burr entrapment. This study aimed to evaluate the incidence, treatment, and outcomes of burr entrapment. METHODS: This multicenter retrospective study analyzed patients who had undergone percutaneous coronary interventions (PCIs) and were treated by RA between May 2013 and March 2022. RESULTS: Of the 22 640 PCI procedures, RA was performed in 3195 patients (14.1%), among whom burr entrapment occurred in 22 patients (0.69%). The mean patient age was 78 ± 8.7 years; 64% were male, and 32% were on dialysis. The entrapped burr size was 1.7 ± 0.2 mm, and the burr/artery ratio was 0.6 ± 0.1. In 20 patients (91%), the burr was extracted by strong manual pullback. The other patients underwent balloon angioplasty at the site of the entrapped burr, which might have provided space for successful burr withdrawal. Major adverse cardiac events occurred in 23% of patients. Tamponade requiring pericardiocentesis occurred in two patients (9%). No patients required emergency surgery or suffered an in-hospital death. CONCLUSIONS: Burr entrapment occurred in 0.69% of patients who had undergone RA. Most burrs were extracted by a strong manual pullback. None required emergency surgery, and there were no in-hospital deaths. The results provide a treatment approach and prognosis for burr stuck in the use of RA.

Incidence of Mid-Term Prognostic Events in Patients With Acute Coronary Syndrome During the Late 2010s in 2 Tertiary Hospitals in a Rural Area of Japan　- A Temporal Comparison.

Background: Data on the incidence of mid-term prognostic events in patients who developed acute coronary syndrome (ACS) in the late 2010s are scarce. Methods and Results: We retrospectively included and collected data for 889 patients with ACS (ST-elevation myocardial infarction [STEMI]/non-ST-elevation ACS [NSTE-ACS]) discharged alive from 2 tertiary hospitals in Izumo City, in rural Japan, between August 2009 and July 2018. Patients were divided into 3 time groups (T1: August 2009-July 2012; T2: August 2012-July 2015; T3: August 2015-July 2018). The cumulative incidence of major adverse cardiovascular events (MACE; comprising all-cause death, recurrent ACS, and stroke), major bleeding, and heart failure hospitalization within 2 years of discharge was compared among the 3 groups. The incidence of freedom from MACE was significantly higher in the T3 group than in the T1 and T2 groups (93 [95% confidence interval {CI} 90-96%] vs. 86% [95% CI 83-90] and 89% [95% CI 90-96], respectively; P=0.03). There was a tendency for a higher incidence of STEMI among patients in T3 (P=0.057). The incidence of NSTE-ACS was comparable among the 3 groups (P=0.31), as was the incidence of major bleeding and hospitalization for heart failure. Conclusions: The incidence of mid-term MACE in patients who developed ACS during the late 2010 s (2015-2018) was lower than that in prior periods (2009-2015).

Very Late Stent Thrombosis after Discontinuation of Antiplatelet Agents during Anticoagulation Therapy in a Patient with Peri-stent Contrast Staining after Implantation of a Second-generation Drug-eluting Stent.

A 54-year-old man was admitted to our hospital due to intermittent chest pain. He had a history of acute myocardial infarction, and peri-stent contrast staining had been observed at the stent implantation site. The patient previously underwent anticoagulation therapy for left ventricular thrombus and antiplatelet therapy to prevent stent thrombosis. More than one year after implantation of a drug-eluting stent, antiplatelet drugs were discontinued, and anticoagulant alone was prescribed according to the guidelines, which resulted in very late stent thrombosis. The risks of both bleeding and thrombosis must be fully considered when deciding whether or not to discontinue antiplatelet therapy during anticoagulation therapy.

Association Between Atrial High-Rate Episodes and Ischemic/Major Bleeding Events in Patients With a Cardiac Implantable Electronic Device　- A 10-Year, Single-Center Historical Cohort Study.

BACKGROUND: An association between atrial high-rate episode (AHRE) and stroke has been reported, although data for the Asian population are limited. This study aimed to investigate the role of AHRE in ischemic and major bleeding events in patients who underwent a cardiac implantable electronic device (CIED) procedure.Methods and Results:This single-center historical cohort study included 710 patients (age: 78±11 years, 374 women) who underwent a CIED-related procedure between October 2009 and September 2019 at Shimane Prefectural Central Hospital (median follow-up period: 4.5 [2.5, 7] years, 3439 person-years). Based on the maximum AHRE burden, patients were divided into: (1) <6 min; (2) ≥6 min to 24-h; and (3) ≥24-h groups. The cumulative incidence of ischemic (ischemic stroke, systemic embolism, and transient ischemic attack) and major bleeding (≥3 Bleeding Academic Research Consortium bleeding criteria) events after the procedure were compared. Uni- and multivariate analyses were performed to identify factors associated with these events. The incidence of both events increased with the rising AHRE burden, being significantly higher in the ≥24-h group than in the <6 min group. Multivariate analysis found age ≥85 years to be the only independent factor associated with both events. CONCLUSIONS: Longer AHRE duration is associated with a high number of major bleeding and ischemic events. Monitoring these bleeding risks is mandatory when clinicians are considering anticoagulation therapy for such patients.

Incidence and Demographic Trends for Acute Coronary Syndrome in a Non-Epidemic Area During the Coronavirus Disease Pandemic in Japan　- A 2-Institutional Observational Study.

Background: We investigated the incidence of acute coronary syndrome (ACS) in a non-epidemic area of coronavirus disease-2019 (COVID-19) in Japan. Methods and Results: This observational study included consecutive patients admitted for ACS at 2 tertiary hospitals in Izumo City during the pandemic in Japan (n=42, March-July 2020). Although the monthly ACS incidence was comparable, the proportions of delayed admissions and high Killip class (III/IV) were significantly higher in this population than in historical cohorts (n=197, 2015-2019). Conclusions: Our findings stress the importance of encouraging patients with ACS-related symptoms to visit medical services promptly, especially in non-epidemic areas.

Trends Over Time in the Incidences of ST-Segment Elevation Myocardial Infarction and Non-ST-Segment Elevation Myocardial Infarction During the Past Decade in a Rural Japanese High-Aged Population.

BACKGROUND: In developed countries, the incidence of non-ST-segment elevation myocardial infarction (NSTEMI) has outpaced that of ST-segment elevation myocardial infarction (STEMI). However, whether this trend is observed in Japan, in which the aging of society is rapidly progressing, remains to be elucidated.Methods and Results:This study retrospectively investigated the trends over time in the incidence of acute coronary syndrome (ACS) between August 2009 and July 2019 at 2 institutions in Izumo City (in rural Japan), which has an elderly population. Crude and age-sex-adjusted incidences of total ACS, STEMI, and non-ST-segment elevation-ACS (NSTE-ACS; including NSTEMI and unstable angina pectoris) were calculated for each year. In the total population, factors associated with the development of NSTEMI were evaluated by multivariate analysis. In total, 1,087 patients were enrolled. The age-adjusted incidence of NSTE-ACS in male patients aged ≥75 years showed a significantly increasing trend. The proportion of NSTEMI per total ACS cases showed a significantly increasing trend over the entire study period. In the multivariate analysis, pre-development use of ≥3 medications for comorbidities was associated with the development of NSTEMI, independent of high-sensitivity cardiac troponin assay use. CONCLUSIONS: This study demonstrated an increasing trend in the incidence of NSTEMI in a rural high-aged Japanese population. In addition to the widespread use of high-sensitivity cardiac troponin assays, early medication use for comorbidities might have contributed to this trend.

The Effectiveness of Target Low-Density Lipoprotein Cholesterol Achieved with Strict Management in Secondary Prevention of Long-Term Coronary Events in Japanese Patients.

BACKGROUND: In the secondary prevention of long-term coronary events, a target value of low-density lipoprotein cholesterol (LDL-C) < 100 mg/dL is recommended as standard management in Japanese guidelines. However, the effectiveness of strict management on lowering LDL-C remains unclear. OBJECTIVES: To clarify whether strict management of LDL-C < 70 mg/dL is more effective in preventing long-term coronary event recurrence than standard management. METHODS: We retrospectively investigated 344 patients with previous percutaneous coronary interventions who underwent late coronary angiography to examine recurrence of cardiac ischemia beyond the early restenosis period from January 2007 to August 2019. Patients were stratified into three groups according to achieved LDL-C value; LDL-C < 70 mg/dL (n = 53), 70 to < 100 mg/dL (n = 130), and ≥ 100 mg/dL (n = 161). Endpoints were acute coronary syndrome (recurrent-ACS) and late coronary revascularization. RESULTS: After follow-up (median 6.0 years), 200 patients (58%) underwent late coronary revascularization, including 94 recurrent-ACS. The incidence of recurrent-ACS was significantly lower in the patients who achieved LDL-C < 70 mg/dL than in those with LDL-C 70 to < 100 mg/dL and LDL-C ≥ 100 mg/dL (p = 0.009 and p = 0.001, respectively). There was no significant difference between the patients with LDL-C 70 to < 100 mg/dL and LDL-C ≥ 100 mg/dL (p = 0.140). There was also no significant difference in late revascularization between the patients with LDL-C < 70 mg/dL and LDL-C 70 to < 100 mg/dL. In patients with LDL-C < 100 mg/dL (n = 183), LDL-C [hazard ratio (HR) 1.035, p = 0.007] and HbA1c (HR 1.338, p = 0.001) were independently associated with recurrent-ACS. CONCLUSIONS: In Japanese patients, LDL-C was a residual risk for recurrent-ACS even after recommended standard LDL-C lowering management target values had been achieved.

Discovery of a new sialic acid binding region that regulates Siglec-7.

Siglec-7 is a human CD33-like siglec, and is localised predominantly on human natural killer (NK) cells and monocytes. Siglec-7 is considered to function as an immunoreceptor in a sialic acid-dependent manner. However, the underlying mechanisms linking sialic acid-binding and function remain unknown. Here, to gain new insights into the ligand-binding properties of Siglec-7, we carried out in silico analysis and site-directed mutagenesis, and found a new sialic acid-binding region (site 2 containing R67) in addition to the well-known primary ligand-binding region (site 1 containing R124). This was supported by equilibrium dialysis, STD-NMR experiments, and inhibition analysis of GD3-binding toward Siglec-7 using synthetic sialoglycoconjugates and a comprehensive set of ganglioside-based glycoconjugates. Our results suggest that the two ligand-binding sites are potentially controlled by each other due to the flexible conformation of the C-C' loop of Siglec-7.

Chemical Synthesis and Evaluation of a Disialic Acid-Containing Dextran Polymer as an Inhibitor for the Interaction between Siglec 7 and Its Ligand.

A new sialic acid (Sia)-containing glycopolymer-a fluorescent probe with high-density disialic acid (diSia) on the surface of polysaccharide dextran (diSia-Dex)-was synthesized as a key molecule to regulate the Sia recognition lectins, Siglecs, that are involved in the immune system. According to our original methods, diSia was synthesized by α-selective sialylation, and a dextran template possessing terminal acetylenes and amino groups was prepared. A diSia and a fluorescent molecule were subsequently introduced to surface-modified dextran by Hüisgen reaction and amidation, respectively. The modulatory activity of Siglec7 was evaluated by using synthetic probes. DiSia-Dex showed high binding avidity toward Siglec7, with a KD value of 5.87×10-10 m, and a high inhibitory activity for the interaction between Siglec7 and a ligand (GD3), with a IC50 value of 1.0 nm. Notably, diSia-Dex was able to release Siglec7 from the pre-existing Siglec7-GD3 complex, possibly due to its unique properties of a slow dissociation rate and a high association rate. Together, these data show that diSia-Dex can be widely applicable as a modulator of Siglec7 functions.

Synthesis of end-functionalized glycopolymers containing α(2,8) disialic acids via π-allyl nickel catalyzed coordinating polymerization and their interaction with Siglec-7.

An allene monomer containing an α(2,8) disialic acid was polymerized by a π-allyl nickel complex with an azido group to produce end-functional glycopolymers with an excellent polydispersity index. The polymers allowed terminal modification with a fluorescent dye by click chemistry. The glycopolymers can dissociate Siglec-7-GD3 interactions at low concentrations.

[Proposal for an auxiliary tool designed to reduce retake rates for lateral radiography of the knee joint].

The reproducibility of lateral radiography of the knee joint in the lateral position is low because patient positioning can be easily affected by passive rotation of the knee joint. We calculated the correction angle of the femoral external rotation and the lower leg elevation and developed our own auxiliary tool for obtaining a lateral view image. We were able to obtain, in a single attempt, an image with misalignment of the condyle limited to less than 7 mm. Our tool also contributed to the reduction of the re-imaging rate, suggesting its usefulness in contributing to a lower re-imaging rate for lateral radiography of the knee joint.