睡眠時無呼吸症候群患者における持続陽圧呼吸療法の交感神経活動抑制効果に関する検討

金沢大学附属病院近年、睡眠時無呼吸症候群(SAS)に対する持続陽圧呼吸(CPAP)療法が心血管イベント抑制効果を認めない事が大規模試験で報告された。しかし、対象患者が軽症であったことが指摘されている。SAS患者は、重症度と交感神経活動の亢進が関連するが、重症例での交感神経活動の評価法は一定した見解がない。申請者施設は、単一筋交感神経活動(single-unit MSNA)を測定できる世界で数少ない施設の一つである。本研究の目的はAHIとsingle-unit MSNAをもとにSAS患者を群分けしCPAP治療前後での冠動脈内プラーク性状及び交感神経活動を評価することでCPAP療法の有効性を再検討することである。本研究は睡眠時無呼吸症候群(SAS)患者に対する持続陽圧呼吸療法(CPAP)の交感神経活動抑制効果を検証することを目的とし行なっている。交感神経活動の評価には筋交感神経活動(MSNA)の測定値を、また実際の心血管イベント及び320列冠動脈CTにより測定した、プラーク性状の変化についても併せて評価している。我々は先行研究によりAHI55以上のSAS患者において、MSNAが特に亢進していることを示しており、本試験では、従来のAHI30以上を最重症とする区分に加え、AHI55以上群を最重症とし、AHI5-30, 30-55, 55以上の3群による、CPAP療法の効果の違いを評価している。現在、CPAP療法開始後5年間のフォローアップにおいて、3群間のCPAP療法はアドヒアランス、及び有効性 (AHI抑制効果)に差は認めていなかった。しかしながら、実際の複合心血管イベントについて、カプランマイヤー曲線を作成したところAHI55以上の群で他2群と比較し、有意なイベント数の増加を認めていた。また、 従来の最重症群である、AHI30以上のグループのイベント数は30未満の群と有意差を認めず、AHI30-55の群においてはCPAP療法は有効に心血管イベントを抑制している可能性が示唆された。現在CPAP療法の心血管イベント抑制効果の是非について、一定した見解は得られていない。この一因として、対象となるSAS患者の重症度分類が、不十分であり、重症度による有効性の違いが詳細に評価されていない可能性がある。本試験からAHI55以上の患者においては、CPAP療法のみでは、交感神経過緊張による残余リスクが解除しきれない可能性が想定される。現在上記結果を論文投稿中である。また、今後集積中の冠動脈CT及び、CPAP療法後のMSNAの結果についての検討、発表も随時予定していく。研究課題/領域番号:19K16289, 研究期間(年度):2019-04-01 – 2020-03-31出典：研究課題「睡眠時無呼吸症候群患者における持続陽圧呼吸療法の交感神経活動抑制効果に関する検討」課題番号19K16289（KAKEN：科学研究費助成事業データベース（国立情報学研究所）） （https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-19K16289/）を加工して作

Intestinal angina in a patient with hypertrophic obstructive cardiomyopathy: a case report

Background: Intestinal angina is characterized by recurrent postprandial abdominal pain and anorexia. Commonly, these symptoms are caused by severe stenosis of at least two vessels among the celiac and mesenteric arteries. However, intestinal perfusion is affected not only by the degree of arterial stenosis but also by systemic perfusion. We experienced a unique case of intestinal angina caused by relatively mild stenosis of the abdominal arteries complicated with hypertrophic obstructive cardiomyopathy. Case presentation: We report an 86-year old Japanese man with hypertrophic obstructive cardiomyopathy and advanced atrioventricular block who was diagnosed with intestinal angina. Computed tomography showed mild stenosis of the celiac artery and severe stenosis of the inferior mesenteric artery, and these lesions were relatively mild compared with other reports. A dual-chamber pacemaker with right ventricular apical pacing was implanted to improve the obstruction of the left ventricular outflow tract. After implantation, the patient\u27s abdominal symptoms diminished markedly, and improvement of the left ventricular outflow tract obstruction was observed. Conclusions: Although intestinal angina is generally defined by severe stenosis of at least two vessels among the celiac and mesenteric arteries, the present case suggests that hemodynamic changes can greatly affect intestinal perfusion and induce intestinal angina in the presence of mild stenosis of the celiac and mesenteric arteries. © 2016 The Author(s)

A 10mg Dose of Amiloride Increases Time to Failure During Blood-Flow-Restricted Plantar Flexion in Healthy Adults Without Influencing Blood Pressure.

Amiloride has been shown to inhibit acid-sensing ion channels (ASIC\u27s), which contribute to ischemia related muscle pain during exercise. Purpose. To determine if a single oral dose of amiloride would improve exercise tolerance and attenuate blood pressure during blood-flow-restricted (BFR) exercise in healthy adults. Methods. Ten subjects (4 female) performed isometric plantar flexion exercise with BFR (30% maximal voluntary contraction) after ingesting either a 10mg dose of amiloride or a volume-matched placebo (random order). Time to failure, time-tension index (TTI) and perceived pain (visual analog scale) were compared between the amiloride and placebo trials. Mean blood pressure, heart rate, blood pressure index (BPI), and BPI normalized to TTI (BPInorm) were also compared between trials using both time matched (TM50 and TM100) and effort matched (T50 and T100) comparisons. Results. Time to failure (+69.4 ± 63.2 seconds, P\u3c0.01) and TTI (+1,441 ± 633 Kg*sec, P=0.02) were both significantly increased in the amiloride trial compared to placebo, despite no increase in pain (+0.4 ± 1.7 cm, P=0.46). In contrast, amiloride had no significant influence on the mean blood pressure or heart rate responses, nor were there any significant differences in BPI or BPInorm between trials when matched for time (all P\u3e0.13). When matched for effort, BPI was significantly greater in the amiloride trial (+5300 ± 1798 mmHg*sec, P=0.01), likely owing to an increase in total exercise duration. Conclusions. A 10mg oral dose of amiloride appears to significantly improve the tolerance to BFR exercise in healthy adults without influencing blood pressure responses

Intestinal angina in a patient with hypertrophic obstructive cardiomyopathy: a case report

BACKGROUND: Intestinal angina is characterized by recurrent postprandial abdominal pain and anorexia. Commonly, these symptoms are caused by severe stenosis of at least two vessels among the celiac and mesenteric arteries. However, intestinal perfusion is affected not only by the degree of arterial stenosis but also by systemic perfusion. We experienced a unique case of intestinal angina caused by relatively mild stenosis of the abdominal arteries complicated with hypertrophic obstructive cardiomyopathy. CASE PRESENTATION: We report an 86-year old Japanese man with hypertrophic obstructive cardiomyopathy and advanced atrioventricular block who was diagnosed with intestinal angina. Computed tomography showed mild stenosis of the celiac artery and severe stenosis of the inferior mesenteric artery, and these lesions were relatively mild compared with other reports. A dual-chamber pacemaker with right ventricular apical pacing was implanted to improve the obstruction of the left ventricular outflow tract. After implantation, the patient’s abdominal symptoms diminished markedly, and improvement of the left ventricular outflow tract obstruction was observed. CONCLUSIONS: Although intestinal angina is generally defined by severe stenosis of at least two vessels among the celiac and mesenteric arteries, the present case suggests that hemodynamic changes can greatly affect intestinal perfusion and induce intestinal angina in the presence of mild stenosis of the celiac and mesenteric arteries