多変量解析を用いた心筋梗塞患者のリハビリテーションについての検討

Assessment of rehabilitation in patients with myocardial infarction by multivariate analysis

　近年，心筋梗塞患者に対して絶対安静は必要最小限にとどめ，早期離床，早期リハビリテーションによる生活指導が心身両面より好ましいことが認識されるようになってきた^1〜3）。一方ME機器，コンピューターの開発に伴って，従来，実施困難とされていた多次元データの解析方法が，臨床医学へ応用されるようになった^4〜7）。中でも最近，質的なデータをも含め，総合的に尺度化し分析する数量化理論^8）の適用が試みられ，心筋梗塞の予後に関しての成績も報告されている^9,10）。今回数量化理論の手法を用いて，急性心筋梗塞患者の特性を規定し得る主な因子を検討した。また急性心筋梗塞患者のリハビリテーション・プログラムに，トレッドミルを用いた多段階運動負荷による定量的チェックをとり入れ，リハビリテーション進行に寄与する因子を検討した。

We have performed the rehabilitation program based on the treadmill exercise test in patients with myocardial infarction and identified the variables that were helpful to predict performance of the maximum exercise level and step up of the rehabil-itation program by multivariate analysis. The study group was composed by 72 patients, 62 men and 10 women, admitted from September, 1980 to June, 1983. Their mean age was 57.6 years old. Tread-mill exercise test of low-level (2. 7METs), middle-level (4.0 METs), high-level (6.6 METs), were undergone on the 12th days, 16th days, and 22nd days, respectively, following the onset of myocardial infarction. The tests were stopped when one of the following endpoints appeared : ( 1 ) symptom ; dyspnea, chest pain and exhaustion, ( 2) horizontal ST-segment change of 0.1mV or more, and junc-tional ST-segment change of 0. 2mV or more, ( 3 ) dangerous arrhythmia, ( 4 ) increase in the heartrate to the submaximal heart rate. From the clinical data, following 9 items were selected for the study ; sex and age, number of attacks, infarcted area, maximal serum levels of CPK･GOT･LDH, serum triglyceride and cholesterol levels, and these items were categorized into 2 or 3 homogenous groups.

By multivariate analysis according to the theory of the quantification III, the serum maximal levels of CPK･GOT･LDH, which are reflecting volume of necrotic myocardium, contributed to the first correlation coefficient and the infarcted area was related with the second correlation coefficient. Cor-onary risk factors such as serum triglyceride and cholesterol levels, and age were related with the third correlation coefficient. The multivariate anal-ysis using the theory of the quantification I reveal-ed that the age and sex, which might relate to the basic exercise tolerance, were the main determinant factors of the performance of the final treadmill exercise level. The maximal levels of GOT and LDH and the numbers of attacks, reflecting the severity of myocardial infarction, had also consid-erable importance. However, the presence of other coronary risk factors, such as high triglyceride and cholesterol levels had the less predictive value.