Spontaneous regression of residential stenosis of the infarct vessel following successful percutaneous transluminal coronary recanalization

: In 64 out of 90 patients with thrombolysis by intracoronary streptokinase (PTCR) in the acute stage of myocardial infarction coronary angiography was performed in the chronic stage after 28 +/- 20 days. 52 of 56 successfully treated patients had a patent infarct vessel in the chronic stage. 36 of these patients showed a spontaneous regression from the subacute to the chronic stage. In 49 of the 56 patients (age: 53.4 +/- 10.4 years) a residual stenosis of more than 75% after PTCR was found; in the chronic stage only 31 patients had a stenosis of more than 75%. Of 10 patients with a spontaneous regression of 25% or more (age: 48.0 +/- 14.9 years) 8 had a one-vessel disease. The infarct vessel was in 6 patients the left anterior descending, in 4 patients the right coronary artery and in no case the left circumflex branch. The results suggest that the indication for invasive interventions, such as acute coronary angioplasty or bypass surgery, does not only depend on the degree of the residual stenosis directly after reperfusion. If possible, the decision for further invasive treatment should depend on the clinical follow-up.