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[Intracoronary thrombolysis in acute myocardial infarction]
Insights
Intracoronary urokinase (UK) infusion effectively lysed coronary thrombi in acute myocardial infarction patients, improving heart function and reducing enzyme peak times. This early-stage treatment showed no fatal complications, demonstrating its efficacy and safety.
Area of Science:
- Cardiology
- Interventional Cardiology
- Thrombosis Research
Background:
- Acute myocardial infarction (AMI) frequently involves intracoronary (IC) thrombi.
- Early reperfusion is critical for salvaging myocardial tissue and improving outcomes.
Purpose of the Study:
- To evaluate the efficacy and safety of IC urokinase (UK) infusion for lysing IC thrombi in AMI patients.
- To assess the impact of IC thrombolysis on coronary patency, left ventricular function, and cardiac enzyme kinetics.
Main Methods:
- Coronary angiography was performed on 36 AMI patients admitted within 12 hours of symptom onset.
- IC infusion of UK (500 units/kg/min for 10-20 min) was administered to patients with total occlusions.
- Coronary patency, ejection fraction, and cardiac enzyme levels (CPK, GOT, LDH) were assessed post-reperfusion and at four-week follow-up.
Main Results:
- IC UK infusion achieved reperfusion in 79.2% of patients with total occlusions.
- Improved coronary patency and left ventricular wall motion were observed in successfully treated groups compared to those with no effect.
- Peak cardiac enzyme levels rose rapidly post-reperfusion, with a shortened interval from symptom onset.
Conclusions:
- IC UK infusion is an effective and safe early-stage treatment for lysing IC thrombi in AMI.
- Reperfusion via IC thrombolysis improves left ventricular function and cardiac enzyme kinetics.
- The procedure demonstrated no fatal arrhythmias or bleeding complications.
Abstract:
To lyse intracoronary (IC) thrombi, coronary angiography was performed for 36 patients with acute myocardial infarction who were admitted within 12 hours of the onset of symptoms. Their average age was 59.6 years. Twenty-four patients (66.7%) had total occlusions of the infarct-related coronary artery, and 12 patients (33.3%) had severe atherosclerotic stenosis without occlusion (group A = Stenosis). In 19 of the 24 patients (79.2%) with total occlusion, IC infusion of urokinase (UK) at a rate of 500 units/kg/min during 10 to 20 min resulted in reperfusion of the distal coronary artery (group B = Thrombolysis). In the remaining five patients, IC thrombolysis was not successfully performed (group C = No effect). The degree of coronary artery stenosis immediately after reperfusion was 88.7 +/- 18.8% in group B. Long-term follow-up (four weeks) coronary angiography in groups A and B revealed improved patency to 79.2 +/- 19.3% and 79.4 +/- 27.8%, respectively. By contrast, total occlusion remained in group C. The ejection fraction measured four weeks later was slightly greater in group B than in group C, and was significantly greater in group A than in group C. If the average ages and complications of the other coronary vessels were considered, a significant difference was recognized among these three groups. The amplitude of the anterior wall motion of the patients with anterior infarction in each group assessed by a point score system was significantly increased in groups A and B as compared to group C. Peak CPK, GOT and LDH rose rapidly immediately after reperfusion and the time interval from the onset of symptoms to peak enzyme production was significantly shortened after reperfusion. These data supported the following concept: 1) coronary thrombus formation frequently occurs in acute myocardial infarction and can be rapidly lysed by IC infusion of UK with a total dose of 250,000 to 600,000 units, 2) reperfusion by lysis of IC thrombi in patients with acute myocardial infarction improves left ventricular wall motion, 3) peak enzyme rises rapidly after reperfusion, 4) the time interval from the onset of symptoms to peak enzyme production is remarkably shortened after repeat perfusion and that 5) no fatal arrhythmia nor bleeding are recognized. Thus, IC infusion of UK in the early stage of acute myocardial infarction was effective and useful.