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The effect of successful intracoronary thrombolysis on left ventricular function in patients with acute myocardial infarction (10 patients with anterior and 13 with inferior infarction) was compared with an untreated matched control group (14 patients with anterior and 28 with inferior infarction). Left ventricular wall motion abnormalities (LVWMA) and ejection fraction (EF) were assessed angiographically 6-8 weeks after the acute event in both groups. The severity and extent of LVWMA was less (P less than 0.01) and the EF was higher (P less than 0.01) in the treated patients with anterior infarction than in the control group. In treated patients with inferior infarction the severity of LVWMA was less (P less than 0.01) than in the control group. No significant difference was found in extent of LVWMA or in EF. These results suggest that thrombolysis reduces left ventricular damage especially in anterior myocardial infarction.

The risk of bleeding associated with intracoronary infusion of streptokinase in acute myocardial infarction was determined in a randomised controlled trial containing 302 patients under the age of 70. Intracoronary streptokinase infusion was given to 152 patients and 150 patients were treated conventionally. Bleeding was seen in 24 (16%) patients in the streptokinase group and in two of the conventionally treated patients. Bleeding was most common (28%) in patients over the age of 60 years. The groin was the site of bleeding in all patients except one. In the first 48 hours after admission the haematocrit in streptokinase treated patients with manifest bleeding fell by 0.07 (0.04) (mean (SD)). The fall in haematocrit in the streptokinase treated patients without manifest bleeding was 0.05 (0.04) and in the conventionally treated patients it fell by 0.03 (0.04). Sixty six units of packed cells were transfused in the streptokinase group (50 units to those who bled); the control group required only 17 units. There were no deaths due to bleeding. The occurrence of bleeding and the fall in haematocrit in the streptokinase group correlated with the occurrence of systemic fibrinolysis but not with the dose of streptokinase given. Thus, in about 15% of patients treatment with intracoronary streptokinase resulted in significant non-fatal bleeding from the femoral puncture site that required substantial transfusion support. Furthermore, there was a significant drop in haematocrit in patients without manifest bleeding. These results emphasise the need for more specific fibrinolytic agents.

The effect of reperfusion achieved by early intracoronary streptokinase in acute myocardial infarction on left ventricular function was studied in 533 patients enrolled in a prospective randomised multicentre study. Two hundred and sixty four patients were allocated to conventional treatment and 269 patients to thrombolysis. At the end of the procedure patency of the infarct related vessel was achieved in 198 (85%) of 234 patients in whom coronary angiography was performed. The median interval from onset of symptoms till the angiographic documentation of patency was 200 minutes. Data were analysed according to the original treatment allocation. Global left ventricular ejection fraction was determined by radionuclide angiography in 418 patients within two days of admission, in 361 patients after two weeks, and in 307 patients after three months. Global left ventricular function remained unchanged throughout the observation period in the control group, whereas it improved during the first two weeks in patients allocated to thrombolytic treatment. Improved function in these patients persisted up to three months after the infarction. Global left ventricular ejection fraction was significantly better in the thrombolysis group than in the control group at two days, two weeks, and at three months. In patients with anterior myocardial infarction the left ventricular ejection fraction was 9% better than in the control group at two weeks and at three months. In the patients with inferior myocardial infarction differences between the two treatment groups were smaller because of photon attenuation within the body. Angiographic evidence suggested that the improvement in function seen after thrombolysis is indeed associated with the patency of the infarct related artery.

The effect of recanalization of the "infarct vessel" on left ventricular (LV) function was assessed 6-8 weeks after acute myocardial infarction (MI) in two groups: patients who had streptokinase-induced recanalization during the acute phase and control patients who had spontaneous recanalization. The ejection fraction and severity of LV wall motion abnormalities in 100 patients with recanalization were compared with those in 78 patients with persistent occlusion of the infarct vessel. Among patients with inferior MI, LV function was significantly better in those with spontaneous (n = 41, p less than 0.05) and streptokinase-induced recanalization (n = 15, p less than 0.02) than in those with persistent occlusion of the infarct vessel (n = 40) in the control group. The LV function was equally good in patients with spontaneous and streptokinase-induced recanalization. Among anterior MI patients, LV function was significantly better in those with streptokinase-induced recanalization (n = 10) than in those with spontaneous recanalization (n = 34, p less than 0.01) or persistent occlusion in the control group (n = 28, p less than 0.001). We conclude that recanalization has a beneficial effect on LV function in patients with MI.

Three hundred and two patients with acute myocardial infarction were enrolled in a randomized multicenter trial to compare conventional treatment with attempted recanalization by intracoronary streptokinase. In a subgroup of patients, the effects of thrombolysis on left ventricular function were evaluated within 48 hr, at 2 wk, and at 3 mo after admission. Global left ventricular ejection fraction (LVEF) was obtained by radionuclide angiography and analyzed with an automatic detection program. Paired data were determined in 160 patients (control 78, thrombolysis 82) within 48 hr and at 2 wk, and in 143 patients (control 71, thrombolysis 72) at 48 hr, 2 wk, and 3 mo. It was shown that LVEF significantly improved in the thrombolysis group as compared with controls both at 2 wk (delta LVEF thrombolysis 3.9 +/- 7.9%, p less than 0.001 compared with delta LVEF control 0.6 +/- 9.7%, p = N.S.) and at 3 mo (delta LVEF thrombolysis 3.1 +/- 12.4%, p less than 0.05 compared with delta LVEF control 2.1 +/- 12.2%, p = N.S.). When patients were divided according to infarct site, however, significant improvement at 3 mo was only observed in the patients with anterior infarction (delta LVEF thrombolysis 5.5 +/- 13.1%, p less than 0.05 compared with delta LVEF control 3.3 +/- 10.4%, p = N.S.). It was shown that acute intervention with intracoronary streptokinase has a potentially favorable and lasting effect on left ventricular function in patients with anterior myocardial infarction. This improvement might be related to the rather rapid administration of thrombolytic therapy with a median time of approximately 4 hr after onset of symptoms.

To investigate the possibility of predicting the occurrence of spontaneous coronary reperfusion in acute myocardial infarction we studied 91 patients in a randomized trial on the clinical efficacy of intracoronary streptokinase compared to conventional treatment. Of the 46 patients treated conventionally 40 had catheterization 6 weeks after the infarction. Spontaneous coronary reperfusion was found in 19 patients (48%). The time to peak CK-MB in these patients was considerably longer than in patients with streptokinase-induced coronary reperfusion and similar to the time in patients without spontaneous coronary reperfusion. Spontaneous coronary reperfusion was associated with a relative improvement of radionuclide ejection fraction from day 1 to day 14 after admission. There was no difference in the occurrence of ventricular arrhythmia or recurrent ischaemic events between the patients with and those without spontaneous coronary reperfusion. Thus, spontaneous coronary reperfusion is not uncommon in traditionally treated myocardial infarction, but its occurrence cannot be predicted by enzymatic or clinical parameters. [ABSTRACT FROM PUBLISHER]