Ikemura, Nobuhiro

写真a

Affiliation

School of Medicine, Department of Internal Medicine (Cardiology) ( Shinanomachi )

Position

Instructor
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Papers 【 Display / hide 】

  • Trends in Unprotected Left Main Percutaneous Coronary Intervention and Clinical Outcomes

    Ikemura N., Mori Y., Chan P.S., Cohen D.J., Yamaji K., Amano T., Kozuma K., Spertus J.A., Kohsaka S.

    JAMA Network Open 9 ( 2 )  2026

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    Importance Unprotected left main percutaneous coronary intervention (LM PCI) is recognized as a reasonable strategy for patients who have coronary artery disease with low anatomic complexity. However, recent trends in its procedural volume, patient characteristics, and procedural techniques and their association with clinical outcomes have not been well described, making it important to confirm the safety of LM PCI in contemporary clinical practice. Objectives To examine temporal trends in the use and in-hospital outcomes of unprotected LM PCI in Japan. Design, Setting, and Participants This retrospective cohort study used prospectively collected data from the nationwide, multicenter Japanese Percutaneous Coronary Intervention registry including approximately 1100 PCI-capable institutions across Japan. Data were restricted to the period after the registry’s 2019 update to ensure consistency in definitions. Temporal trends in PCI procedures were analyzed from January 2019 through December 2023. Patients with prior coronary artery bypass grafting, recent cardiogenic shock, cardiac arrest within 24 hours of treatment, restenosis, or balloon angioplasty alone were excluded. Exposures Calendar year of PCI (2019-2023). Main Outcomes and Measures The primary outcome was in-hospital mortality. Multivariable logistic regression was used to assess temporal trends and whether differences were explained by baseline or procedural characteristics. Results Among 851 468 included procedures (mean [SD] patient age, 74.1 [10.2] years; 78.1% men), unprotected LM PCI accounted for 9490 of 182 739 PCI procedures in 2019 (5.2%) and 8583 of 164 332 in 2023 (5.2%). From 2019 to 2023, mean (SD) patient age increased from 73.4 (10.1) to 74.6 (10.1) years, and patients were more likely to have heart failure (increasing from 1676 of 9058 cases in 2019 [18.5%] to 1704 of 8200 [20.8%] in 2023). Unadjusted in-hospital mortality increased from 148 cases in 2019 (1.6%) to 157 in 2023 (1.9%), but this was not significant after adjusting for patient characteristics (adjusted odds ratio for 2023 vs 2019: 1.08; 95% CI, 0.85-1.37). From 2019 to 2023, further adjustment for procedural factors, including increased use of radial access (from 5789 cases [63.9%] to 5985 cases [73.0%]) and mechanical circulatory support (from 828 cases [9.1%] to 941 cases [11.5%]), did not alter the association between year and mortality. Conclusions and Relevance In a nationwide Japanese PCI registry, unprotected LM PCI consistently accounted for 5% of PCI procedures. Although unadjusted in-hospital mortality rose modestly over time, the findings indicate this was largely explained by increasing patient complexity, with risk-adjusted outcomes remaining stable, supporting the continued role of LM PCI as a safe revascularization option in contemporary practice.

  • Accuracy of Physician Estimation of Thromboembolic Risk and Its Association With Oral Anticoagulant Utilization for the Management of Atrial Fibrillation

    Miyama H., Ikemura N., Kohsaka S., Kimura T., Katsumata Y., Ueda I., Tanimoto K., Cheung J.W., Takatsuki S., Ieda M.

    American Journal of Cardiology 254   113 - 118 2025.11

    ISSN  00029149

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    Clinical practice guidelines for atrial fibrillation (AF) recommend thromboembolic risk stratification using empirical risk scores. We aimed to investigate how appropriately physicians recognize patients' actual thromboembolic risk and how this correlates with the use of oral anticoagulants (OACs). This prospective cohort study enrolled consecutive patients with initial AF treatment. Physicians were asked to numerically estimate each patient's thromboembolic risk, which was consecutively categorized as low (<1.0%/year), intermediate (1.0%≤ to <2.0%/year), or high risk (2.0%≤/year). The empirical thromboembolic risk was defined by the CHA<inf>2</inf>DS<inf>2</inf>-VASc score and categorized into 3 groups: low (0 or 1 point), intermediate (2 points), and high risk (3≤ points). Overestimation and underestimation were defined as physicians assigning a higher or lower risk category than the empirical risk. A multivariable logistic regression model was constructed to investigate the association between physicians' underestimation and OAC use. Among the 285 patients (68±12 years, female 27%), the mean CHA<inf>2</inf>DS<inf>2</inf>-VASc score was 2.3 ± 1.6. The thromboembolic risk was accurately estimated by treating physicians in 51.6% of cases, while 39.6% were overestimated and 8.8% were underestimated. OACs were used in 89.8%, 84.1%, and 72.0% of the correctly, over, and underestimated group, respectively. After multivariable adjustment, physicians' underestimation of thromboembolic risk was independently associated with less use of OACs (adjusted OR 0.17, 95% CI 0.05-0.54, P = 0.003). In conclusion, physicians frequently misrecognized thromboembolic risk in AF patients. Risk underestimation was independently associated with lower OAC use, suggesting the importance of integrating validated risk stratification tools into clinical practice to enhance shared decision-making.

  • Association of Acute Kidney Injury Risk and Same-Day Discharge Practices After Percutaneous Coronary Intervention

    Uzendu A., El Zein R., Rymer J.A., Nguyen D.D., Angel Garcia R., Ikemura N., Butala N., Julien H.M., Girotra S., Kumbhani D.J., Olafiranye O., Young R., Brothers L., Spertus J.A.

    Journal of the American Heart Association 14 ( 21 ) 1 - 10 2025.10

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    BACKGROUND: Same-day discharge (SDD) after percutaneous coronary intervention (PCI) may be altered when complications occur. We sought to determine whether risk of the most common complication, acute kidney injury (AKI), is associated with SDD in practice. METHODS: Using the NCDR (National Cardiovascular Data Registry) CathPCI registry, we calculated the AKI risk for elective PCIs from 2018 to 2022 using the NCDR prediction model. Hierarchical logistic regression models were constructed to predict SDD with AKI risk and procedural variables as fixed effects, and site as a random effect. Trends in SDD rate across AKI risk categories were described and variability across sites was quantified using median odds ratios (ORs). RESULTS: Among 1 033 096 eligible patients, 414 297 (40.1%) had SDD after PCI and rates increased throughout the study period (27.9% in 2018 to 53.4% in 2022; 1.9% per quarter). Higher AKI risks were associated with lower SDD rates (OR, 0.97 per 1% increase in AKI risk [95% CI 0.968–0.971]) although even in 2022, 41.2% of high-risk patients underwent SDD. Marked variation in SDD practices was observed across sites (overall median OR, 3.75 [95% CI 2.63–5.34]) even among the highest risk group (median OR, 3.60 [95% CI 2.34–5.56]). CONCLUSIONS: Although patients at higher risk of AKI are less likely to undergo SDD overall, currently, 2 in 5 patients with >10% AKI risk are discharged the day of their procedure with marked variation across sites. Further work is needed to better understand the postdischarge risk of SDD in patients at higher AKI risk to improve delivery and safety of PCI.

  • Response to the letter to the editor: “The obesity paradox and collider bias, the elephant in the room”

    Ikemura N., Chan P.S.

    Resuscitation 215 2025.10

    ISSN  03009572

  • Trajectories of Angina After Initial Invasive vs Conservative Strategy for Chronic Coronary Disease

    Ikemura N., Jones P.G., Fu Z., Chan P.S., Sherrod C.F., Arnold S.V., Cohen D.J., Mark D.B., Maron D.J., Hochman J.S., Spertus J.A.

    Journal of the American College of Cardiology 86 ( 11 ) 782 - 793 2025.09

    ISSN  07351097

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    Background: Clinical trials typically report average health status outcomes by treatment at single points in time, as opposed to participants’ trajectories (or journeys) over time. Although ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches) demonstrated better mean health status at discrete times with an invasive treatment among those with baseline angina, the patterns of individual participants’ angina over time are unknown. Objectives: The purpose of this study was to identify patterns of individual participants’ angina over time after invasive or conservative management strategies for chronic coronary disease. Methods: In this secondary analysis of the ISCHEMIA trial, which enrolled participants with chronic coronary disease and moderate to severe ischemia from July 2012 to January 2018, we used ordinal latent trajectory analysis to assess angina frequency over a 2-year period, separately for participants assigned to the initial invasive and initial conservative arms. Angina frequency was defined using the SAQ-AF (Seattle Angina Questionnaire Angina Frequency) score, recategorized as daily/weekly (0-60 points), monthly (61-99 points), and no angina (100 points). Participants without baseline angina were excluded. Results: Among 2,977 participants with baseline angina, 1,505 (50.6%) were randomized to initial invasive and 1,472 (49.4%) to initial conservative management; baseline characteristics were well balanced between groups. Six distinct patterns of angina trajectories were identified in each arm and were qualitatively similar: 1) rapid resolution; 2) gradual resolution; 3) early improvement with persistent infrequent angina; 4) severe angina with improvement; 5) modest angina with minimal change; and 6) severe angina without improvement. In the invasive group, the most common patterns included rapid resolution (27.1%) and early improvement with persistent infrequent angina (32.1%), whereas the conservative group more often showed modest angina with minimal change (42.1%) and fewer cases of rapid resolution (12.8%) or early improvement with persistent infrequent angina (10.2%). Conclusions: Patients with chronic coronary disease and angina experienced diverse symptom trajectories, ranging from rapid resolution to severe or persistent angina. A greater proportion of conservatively managed patients experienced unfavorable angina patterns over 2 years compared with those treated invasively. When health status is monitored over time, such patterns may help identify patients with persistent symptoms who could benefit from additional therapy. (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches [ISCHEMIA]; NCT01471522)

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