抗血栓療法中の出血リスク、脳梗塞リスクを一度に予測できるスコア開発～実臨床における適切な意思決定に役立つ可能性～

2025-07-24

2025-07-23 国立循環器病研究センター

国立循環器病研究センターは、抗血栓療法中の出血リスクと脳梗塞リスクを同時に高精度で予測可能な新しいスコア法を開発した。国内52施設によるBAT2研究データを基に、既存の動脈硬化危険因子に加え、脳小血管病や頭蓋内血管狭窄といったMRI画像所見を取り入れることで予測精度を向上。このスコアは、特に頭蓋内出血も予測可能で、臨床現場での抗血栓療法の最適化に貢献が期待される。

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隠れた血管性脳損傷と臨床的特徴を用いた長期抗血栓療法の最適化予測モデル Prediction Model to Optimize Long-Term Antithrombotic Therapy Using Covert Vascular Brain Injury and Clinical Features

Kaori Miwa, MD, PhD, Kenta Tanaka, MS, Masatoshi Koga, MD, PhD, Kanta Tanaka, MD, PhD, Yusuke Yakushiji, MD, PhD, Makoto Sasaki, MD, PhD, Kohsuke Kudo, MD, PhD, …,
Stroke Published 19 June 2025
DOI:https://doi.org/10.1161/STROKEAHA.125.050859

Abstract

BACKGROUND:

Defining the risk of developing major bleeding, especially intracranial hemorrhage (ICH), or ischemic stroke (IS) in patients receiving antithrombotic therapy is crucial. Existing risk prediction tools would inadequately assess the net clinical benefit of antithrombotic therapy. We aimed to develop novel risk scores incorporating covert vascular brain injury to personalize the risk assessment of major bleeding, ICH, and IS in patients receiving antithrombotic therapy.

METHODS:

The prospective, multicenter, observational study (BAT2 [Bleeding With Antithrombotic Therapy Study-2]) enrolled patients receiving oral antiplatelets or anticoagulants from 52 hospitals across Japan between 2016 and 2019. Multimodal brain magnetic resonance imaging was performed at baseline under prespecified conditions to determine cerebral small vessel disease (white matter hyperintensity, cerebral microbleed, lacune, enlarged perivascular space, and cortical superficial siderosis), nonlacunar infarct, and intracranial artery disease with central reading. Risk scores, collectively termed the BAT2 scores, were developed separately to evaluate the comparative risks of (1) major bleeding, (2) ICH, and (3) IS based on covariates from Cox proportional hazards models and clinical relevance. Model performance was assessed with the Harrell C-index and calibration slope adjusted for optimism via bootstrapping.

RESULTS:

Of 5378 patients enrolled, 5250 were analyzed (mean age, 71±11 years, 33% women); 93 experienced major bleeding, including 55 had ICH, and 197 had IS during a median follow-up of 2.0 years. Predictors for bleeding included age, underweight, renal impairment, hypertension, cerebral microbleed, lacune, and antithrombotic treatment type. Predictors for ICH further included deep white matter hyperintensity but not renal impairment. For IS, predictors included age, renal impairment, diabetes, atrial fibrillation, lacune, cerebral microbleed, nonlacunar infarct, and intracranial artery disease. Prediction performance showed optimism-adjusted C-index and calibration slope of 0.69 (95% CI, 0.64–0.74) and 0.82 (95% CI, 0.62–1.06) for bleeding, 0.75 (95% CI, 0.67–0.80) and 0.80 (95% CI, 0.56–1.02) for ICH, and 0.64 (95% CI, 0.60–0.68) and 0.92 (95% CI, 0.73–1.18) for IS.