Comprehensive risk stratification of left atrial appendage thrombus to prevent cardioembolic stroke

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K17586
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 53020:Cardiology-related
• Research Institution: University of Tsukuba
• Principal Investigator: Machino Tomoko 筑波大学, 医学医療系, 講師 (20755673)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 心房細動 / 心原性塞栓症

Outline of Final Research Achievements

We investigated the characteristics and factors associated with a large LAA ostium in Japanese patients with NVAF. In 1102 NVAF patients, the maximum LAA diameter was measured using transesophageal echocardiography (TEE). A large LAA ostium was defined by a maximum diameter of >30 mm. A large LAA ostium was observed in 3.1% of all participants and 8.9% patients with long-standing persistent AF (LSAF). The large LAA group had greater CHA2DS2-VASc (p=0.024) and HAS-BLED scores (p=0.046) and a higher prevalence of LAA thrombus (p=0.004) than did the normal LAA group. LSAF, moderate or severe mitral regurgitation, left atrial volume dilatation, increasing E/E’ ratio and left ventricular mass were independently associated with a large LAA ostium (p<0.001, p<0.001, p=0.009, p=0.009, and p=0.032, respectively). NVAF patients with a large LAA ostium may have a higher risk of stroke and bleeding. LSAF and factors leading to LA overload may be closely associated with LAA ostial dilatation.

Free Research Field

循環器内科学

Academic Significance and Societal Importance of the Research Achievements

日本における経皮的左心耳閉鎖術の適応を満たす，心原性塞栓症および出血リスクの高い症例の約1割において，左心耳入口部の拡大により，既存の左心耳閉鎖デバイスでは安全に治療ができない可能性が示唆された。長期の心房細動持続および左房負荷につながる因子（左室肥大，左室拡張障害，僧帽弁逆流の増悪）は，左心耳入口部拡大を促進する可能性があり，それらの因子が左心耳拡大を進行させる前に，経皮的左心耳拡大術を考慮すべきであると考えられた。また今後日本人向けに，より大きいサイズの左心耳閉鎖デバイスの開発が必要であると考えられる。