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Effects of coronary thrombolysis on left ventricular ejection fraction in patients with acute myocardial infarction
K Ishikawa1, A Oda, K Kanamasa
1First Department of Internal Medicine, Kinki University School of Medicine, Osaka, Japan.
Insights
Successful coronary thrombolysis preserves left ventricular function after myocardial infarction. Unresolved coronary artery occlusion leads to further deterioration of heart function, highlighting the benefits of recanalization therapies.
Area of Science:
- Cardiology
- Interventional Cardiology
- Cardiovascular Imaging
Background:
- Acute myocardial infarction (AMI) significantly impacts left ventricular (LV) function.
- Coronary artery patency is crucial for myocardial salvage and LV recovery post-AMI.
- Urokinase therapy is a potential treatment for restoring coronary blood flow.
Purpose of the Study:
- To evaluate the impact of coronary artery recanalization on left ventricular function in patients with acute myocardial infarction.
- To compare the long-term effects of successful versus unsuccessful urokinase therapy on global and regional ejection fractions.
- To assess the role of spontaneous versus urokinase-induced recanalization.
Main Methods:
- Serial left ventriculograms were performed on 65 AMI patients (admission and 3 months later).
- Urokinase was administered intravenously and/or intracoronarily in 29 patients; 17 served as controls.
- Coronary artery status (occluded or recanalized) and LV ejection fractions (global and regional) were assessed.
Main Results:
- Patients with persistent coronary occlusion after urokinase showed a significant decline in global ejection fraction (54% to 46%, p<0.001).
- Successful recanalization maintained global ejection fraction (52% in both stages).
- Regional ejection fraction of the infarcted area improved in successful recanalization patients (22% to 27%) but not in unsuccessful cases (20% to 18%). Spontaneously recanalized patients had the highest ejection fractions.
Conclusions:
- Persistent coronary artery occlusion following acute myocardial infarction leads to progressive deterioration of left ventricular function.
- Successful coronary thrombolysis, including spontaneous recanalization, can salvage jeopardized myocardium and preserve or improve left ventricular function.
- Early restoration of coronary blood flow is critical for optimizing outcomes in acute myocardial infarction.
Abstract:
Left ventriculograms were performed on 65 patients with acute myocardial infarction, once upon admission and again 3 months later. In 29 cases urokinase was injected intravenously and/or intracoronarily. The other 17 were treated without urokinase. In 8 out of 29 patients whose infarct-related coronary arteries remained completely occluded following urokinase therapy, the global ejection fraction was reduced from 54 +/- 3% during the acute stage to 46 +/- 5% during the chronic stage (p less than 0.001). However, for the 21 patients whose coronary arteries were successfully recanalized, the 2 values were the same (52 +/- 2%). The highest global ejection fractions were seen in 19 spontaneously recanalized patients (acute: 54 +/- 2%, chronic: 55 +/- 2%). For the 8 unsuccessful patients, the regional ejection fraction for the infarcted portion was reduced from 20 +/- 5% during the acute stage to 18 +/- 6% during the chronic stage. But for the successful patients there was an improvement from 22 +/- 2% during the acute stage to 27 +/- 2% during the chronic stage. Again, the regional ejection fraction was the highest for the spontaneously recanalized group, being 31 +/- 2% and 36 +/- 3% during the acute and chronic stages, respectively. These results indicate that if the coronary artery remains occluded during the acute stage the reduced left ventricular function continues to deteriorate even more during the chronic stage. Successful coronary thrombolysis, however, might salvage the infarcted myocardium as well as preserve the function of the left ventricle.