Elderly patients are commonly excluded from cardiac rehabilitation after myocardial infarction (MI). The present controlled, non-randomized trial was undertaken as a preliminary study to compare some effects of cardiac rehabilitation between patients younger and older than 65 years without contraindications to physical exercise. Baseline total work capacity (TWC) was assessed by a maximal ergometric stress testing 4 weeks after MI. Patients were then prospectively enrolled into an 8-week ambulatory rehabilitation program (R-group: age < or = 65 N = 16; age > 65 N = 16). Those who refused or who could not participate in the program because of logistic difficulties served as controls (NR-group: age < or = 65 N = 16; age > 65 N = 14). In spite of non-randomized allocation, clinical characteristics did not differ between either treatment groups or age groups. TWC was re-assessed at 8 weeks from baseline evaluation in all patients. The number of completed training sessions in the R-group, and the proportion of sessions which were suspended for physiological or pathological (adverse events during exercise) causes were similar under and over 65 years. TWC increased (p < 0.001) in the R-group, the improvement being similar in the two age cohorts (< or = 65: +55% vs > 65: +65%, NS). A spontaneous enhancement of TWC (+37%, p < 0.001) occurred among younger controls as well. Only older controls did not improve their TWC; moreover, their +16% change was significantly (p < 0.05) less than the +65% increase obtained by the R-group of the same age.(ABSTRACT TRUNCATED AT 250 WORDS)