煙草 敏¹, 原田 昌彦¹, 宮坂 匠¹, 吉川 浩一¹, 寳田 雄一¹, 桝谷 直司¹, 林 京子¹, 原 文彦²

Satoshi TABAKO¹, Masahiko HARADA¹, Takumi MIYASAKA¹, Koichi YOSHIKAWA¹, Yuichi TAKARADA¹, Naoji MASUYA¹, Kyoko HAYASHI¹, Fumihiko HARA²

¹東邦大学医療センター大森病院臨床生理機能検査部, ²東邦大学医療センター大森病院循環器内科

¹Department of Clinical Functional Physiology, Toho University Omori Medical Center, ²Cardiovascular Medicine, Toho University Omori Medical Center

キーワード : left ventricular diastolic function, echocardiography, left ventricular mass index, left atrial volume index, hypertension

はじめに：高血圧症における左房拡大や左室肥大が心血管疾患発症の予測因子であることが知られている．本研究の目的は心エコー図指標から高血圧患者の心血管イベント発症の層別化が可能であるか否かを検討することである．対象と方法：対象は，当院で心エコー図検査を施行した20‐80歳代の薬物治療を受けている高血圧患者連続357例（平均年齢：64.7±13.4歳，男/女：194/163例）．心房細動例，虚血性心疾患例，中等度以上の僧帽弁逆流例，追跡困難な高血圧患者は除外した．患者背景因子ならびに心エコー図指標と心血管イベント（心不全，急性冠症候群，脳卒中）発症との関連について検討した．結果：心エコー図検査施行後の経過観察期間中（平均821±443日）に24例（心不全11例，急性冠症候群5例，脳卒中8例）がイベントを発症した．全症例をイベントの有無で2群に分類した．ロジスティック回帰分析による単変量解析で有意差を認めた項目を説明変数として多変量解析を行った結果，左房容積係数（LAVI）及び左室心筋重量係数（LVMI）は心血管イベントの予測因子であった（LAVI：OR 1.07，p＝0.003，LVMI：OR 1.02，p＝0.007）．LAVI及びLVMIを4グレード（正常：0点，mildly：1点，moderately：2点，severely：3点）に分類しスコア化，全症例のLAVIとLVMIの両スコアの総計をLALV indexとした．Kaplan-Meier法による生存分析を行ったところ，LALV indexが増すにつれイベント発生率は有意に高値であった（Log-rank, p＜0.0001）．結論：高血圧治療患者において，LAVI及びLVMIの両指標を用いた定量的評価は，心血管イベント発症の予測に有用である可能性が示唆された．

Introduction: Atrial dilation and left ventricular hypertrophy in hypertensive patients are known predictive factors for cardiovascular disease. We investigated whether stratification of the cardiovascular events onset was possible from echocardiographic parameters in patients with hypertension. Subjects and methods: The subjects were 357 consecutive patients with hypertension receiving drug therapy and were aged from their 20’s through their 80’s (mean age: 64.7±13.4 years, males/females: 194/163) who had undergone echocardiographic examination. Patients with atrial fibrillation, ischemic heart disease, and more-than-moderate mitral valve regurgitation, as well as hypertensive patients in whom it was difficult to perform follow-up examinations, were excluded. The relation between the patients’ clinical characteristics, echocardiographic parameters, and incidence of cardiovascular events (heart failure, acute coronary syndrome, and stroke) were investigated. Results: Events occurred in 24 cases (11 cases of heart failure, 5 cases of acute coronary syndrome, and 8 cases of stroke) while we were observing patient progress after echocardiography (average: 821±443 days). The subjects were divided into 2 groups depending upon whether or not an event had occurred. A multivariate analysis with an explanatory variable for items for which a univariate analysis using logistic regression analysis had shown a significant difference, showed that left atrial volume index (LAVI) and left ventricular mass index (LVMI) were predictive factors for occurrence of cardiovascular events [LAVI: Odds Ratio (OR) 1.07, p=0.003, LVMI: OR 1.02, p=0.007]. LAVI and LVMI were divided into 4 grades (normal, mild, moderate, and severe) and scored from 0 to 3 points. The LALV index was defined as the total LAVI and LVMI scores of all subjects. When a survival analysis was conducted according to the Kaplan-Meier method, the incidence of cardiovascular events was significantly higher (Log-rank, p＜0.0001) when the LALV index was higher. Conclusion: Our results suggest that quantitative evaluation using both LAVI and LVMI indices is a useful method for predicting occurrence of cardiovascular events in patients receiving hypertension therapy.