[Prognostic value after 1 year of post-infarction exercise test with measurement of oxygen consumption]

A symptoms-limited exercise stress test with measurement of myocardial oxygen consumption (VO2) was carried out in 56 patients on the 44th +/- 16 days after infarction and in 48 patients on the 119th +/- 31 days. Analysis of the expired gases was performed by mass spectrography, cycle by cycle. The second test was coupled with an exercise gamma-angiography in 40 cases. The parameters on exercise were analysed in two groups at one year: group 1 asymptomatic and group 2 symptomatic (subgroup 2a with angina but no dyspnoea, subgroup 2b with dyspnoea). At the second test, the peak VO2 was lower in group 2 (19.46 +/- 5.78 ml/mn/kg) than in group 1 (24.2 +/- 6.5 ml/mn/kg) (p less than 0.008) irrespective of the symptom (angina and/or dyspnoea). The oxygen pulse was lower in group 2a with angina at one year (42.4% +/- 14.3%) compared with asymptomatic group 1 patient (58.5 +/- 12.4%) (p = 0.03). The 3 parameters: VO2, blood pressure and ejection fraction on exercise were independent. The lack of physical fitness may partially explain the absence of variation of the peak VO2 at the first test. These preliminary results should be confirmed by a multivariate analysis in a larger patient group.