The object of this study was to assess and analyse TIMI (Thrombolysis in Myocardial Infarction) grade and secondary major cardiac events of patients with acute myocardial infarction benefiting from pre-hospital thrombolysis according to their predefined clinical and electrical "ischaemic status" (Active, Inactive, Intermediate) on admission to the coronary care unit and at the end of thrombolysis (90th minute). This single centre study was undertaken from March 1994 to August 1999 on 161 patients treated by thrombolysis by the emergency ambulance service for acute myocardial infarction (< or = 6 hours). The mean age was 56.2 +/- 11.3 years with 8.7% of women. On admission to the coronary care unit. 30.8% were classified as Inactive and 51.6% as Active. At the end of thrombolysis, 62.3% were classified as Inactive and 27.7% as Active. Nearly 93% of TIMI 3 flow was observed in Inactive patients at the 90th minute and 76.7% of TIMI < or = 2 flow in Active patients (p < 0.0001). Global hospital mortality was 2.48% but it was zero in the Inactive group at the end of thrombolysis. With an average follow-up of 26.9 +/- 15.8 months, the incidence of major cardiac events was 34.1%, including 16.1% of revascularisation of the target lesion. In multivariate analysis, predictive factors for TIMI < or = 2 at the end of thrombolysis included persistent pain, the number of leads with ST elevation and the absence of regression of ST elevation on admission to the coronary care unit. The only predictive factor for secondary major cardiac events was persistent ST elevation at the 90th minute of thrombolysis.