Feasibility of physical training after myocardial infarction and its effect on return to work, morbidity and mortality.Acta Med Scand Suppl. 1976; 599:7-84.AM
The purpose of this work on patients with myocardial infarction was to find out whether physical rehabilitation based on spontaneous home training can be carried out in practice, and whether such rehabilitation brings about favourable changes in the symptoms, clinical findings and metabolic risk factors. A further objective was to find out whether the physical condition of the patients is improved, and whether the rehabilitation has any effect on the prognosis and return to work. The training group consisted of 180 patients, 143 men and 37 women. The control group comprised 200 patients, 166 men and 34 women. All the patients were of working-age, (under 65 yrs) and all were treated in the Clinic of Internal Medicine, University Central Hospital of Oulu. Mobilization was early: the intramural infarctions were discharged on the 12th day, and the transmural ones on the 16th day. Rehabilitation was started 10 weeks after the onset of infarction. The training subjects came for a chalistenic session in groups of 5-7, once a month. During the session they learnt a 30-minute series of chalistenic movements under the instruction of a physiotherapist, and the supervision of a physician. The chalistenic program was an interval type program, involving all the large muscle groups and including running on the spot. The training became progressively more strenuous every month. The trainers were to perform the program every day at home. During each session in a gymnastic hall, the subjects took a bicycle ergometer test. The controls came for an ergometric test monthly. The patients were examined in an outpatient department every third month. The improvement of their physical condition was followed by determining the submaximal value of aerobic power, measured as the work load at a heart rate of 130 per minute (Physical Working Capacity 130). Furthermore, the subjective maximum-of about one fourth of the trainers and controls was determined in the ergometric test. The program turned out to be suitable. After 6 months, 78% of the training men and 65% of the training women were still participating, and 67% of the training men and 62% of the training women attended the last session after 12 months. The chalistenic home program was carried out enthusiastically. Of the training men who were still participating after 6 months, 55% did their exercises on 6-7 days of the week, the corresponding figure for the training women being 70%; after a year 51% of the men and 73% of the women were still equally active. At the time of the 12-month checkup, 15% of the men and 14% of the women did an insignificant amount of chalistenic exercises (0-2 times a week). Rehabilitation had no effect on the clinical condition of the trainers, for no significant differences were noted in the symptoms of coronary disease and the clinical findings between the training subjects and the controls. One indication of a possible favourable training effect was the decrease of prolonged chest pains in the male training group, during the follow-up period. The blood pressure of the training men and the training women declined, but the difference in comparison with the controls was not significant. At the end of the follow-up year the training men were less fatigued subjectively than the controls, which may be indicative of a favourable psychic effect of rehabilitation. Rehabilitation had no effect on the smoking habits. There were no significant differences in the ECG findings between the trainers and the controls. The relative heart volume of both the training men and the training women increased during the year. In the initial checkup, the mean relative heart volume of the training men was 496 cm3/m2 and that of the training women 487 cm3/m2, while at the end of the year the figures were 506 cm3/m2 for men and 530 cm3/m2 for women. The difference between the trainers and the controls was almost significant in both groups at the end of the year. The clinical findings in the training group showed no signs of an increase of heart failure at the end of the year. Rehabilitation had no effect on serum cholesterol, serum triglycerides or serum urate, or 2-hour glucose tolerance. No association between training and the increase in physical working capacity 130 could be shown. PWC 130 increased significantly in the groups of trainers and controls, but more so in the control group. At the end of the year, the trainers had a 13.3% higher PWC 130 and the controls an 18.3% higher PWC 130 than observed initially. PWC 130 improved by over 20% in 39.1% of the trainers and 44.6% of the controls. The physical working capacity improved more rapidly in the group of trainers than in the control group. Those training men, however, for whom the subjective maximum was determined, seemed to improve their physical working capacity more than the controls, for the subjective maximum of the training men improved significantly (39.3%). The improvement among the control men was not significant (31.7%). The training effect achieved by the training men was probably peripheral, and did not become manifest in the PWC 130 measurements. Rehabilitation had no effect on the return to work. Forty (42.1%) of the training men recovered their working capacity, and 37 (39%) of these returned to their previous employment; the corresponding figures for the control men were 36 (33%) and 35 (32.1%). Seven (25.9%) of the training women and 5 (33.3%) of the control women resumed their previous employment. The prognosis of the training subjects was followed for an average of 31.5 months and that of the controls for an average of 26.5 months. During the follow-up period, 21 trainers (11.7%) and 29 controls (14.5%) suffered a re-infarction. There were 18 (10%) coronary deaths in the training group and 28 (14%) in the control group. During the first year 3.5% of the trainers and 8% of the controls died. During the second year mortality was 3.6% in the training group and 5.5% in the control group. The trainers and controls did not differ significantly as regards recidivous infarctions and coronary deaths. It should be noted, however, that the differences in both recidivous morbidity and coronary mortality were always in the same direction: the trainers had lower values of recidivous morbidity and coronary mortality than the controls. Training may have had an effect on the prognosis.