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Early dysfunction and long-term improvement in endothelium-dependent vasodilation in the infarct-related artery after
Emili Iràculis1, Angel Cequier, Joan Antoni Gómez-Hospital
1Servei de Cardiologia, Hospital de Bellvitge, Universitat de Barcelona, C/Feixa Llarga s/n, L'Hospitalet de Llobregat, 08907 Barcelona, Spain.
Insights
Patients treated for acute myocardial infarction (AMI) with thrombolysis show early endothelial dysfunction in the infarct-related artery (IRA). This dysfunction improves over one year if the IRA remains patent, suggesting a stunned endothelium post-AMI.
Area of Science:
- Cardiology
- Vascular Biology
- Interventional Cardiology
Background:
- Endothelial dysfunction is a key factor in cardiovascular disease.
- Previous studies noted coronary flow reserve alterations post-thrombolysis, but endothelium-dependent vasomotion remained unexamined.
Purpose of the Study:
- To assess endothelial dysfunction in the infarct-related artery (IRA) after acute myocardial infarction (AMI) in patients treated with thrombolysis.
- To evaluate the subsequent status of this endothelial dysfunction one year later.
Main Methods:
- Acetylcholine (ACh) infusion was used to assess endothelial function in the IRA of AMI patients post-thrombolysis.
- Quantitative coronary angiography measured distal arterial diameter changes.
- Control group comprised patients with coronary atherosclerosis.
- Clinical, ECG, and biochemical markers determined reperfusion timing and infarct extent.
Main Results:
- Initially, AMI patients exhibited significant vasoconstriction to ACh in the IRA (-20% vs. 4% in controls, p<0.01).
- Vasoconstriction correlated with creatine kinase-MB levels and new Q waves.
- One year later, among 8 patients with a patent IRA, endothelial response improved significantly (+3% vs. -19%, p<0.05).
Conclusions:
- Severe endothelial dysfunction in the IRA is evident early in AMI patients treated with thrombolysis.
- Improvement in endothelial function is observed during follow-up in patients maintaining IRA patency.
- These findings suggest a 'stunned endothelium' component in the early days following AMI.
Objectives:
This study assessed the degree of endothelial dysfunction in post-acute myocardial infarction (AMI) and its subsequent status in the infarct-related artery (IRA) in patients treated with thrombolysis.
Background:
Coronary flow reserve alterations in the IRA after thrombolysis have been described, but the endothelium-dependent vasomotion has not been investigated, to date.
Methods:
Endothelial function in patients after thrombolysis was assessed by infusion of acetylcholine (ACh) at increasing doses in the IRA. Diameter changes in the distal segments were evaluated using quantitative coronary angiography. Patients with coronary atherosclerosis constituted the control group. Clinical variables, electrocardiography and biochemical markers were used to determine the timing of reperfusion and the extent of the infarct. Patients in the AMI group were re-evaluated one year later.
Results:
In the initial assessment, 16 patients showed a vasoconstriction response to ACh in the IRA compared to the control group (-20 +/- 21% vs. 4 +/- 4%; p < 0.01). Significant correlations between the degree of vasoconstriction and maximum value of the creatine kinase-MB fraction and number of new Q waves were observed. Of the 12 patients re-evaluated, 4 had complete occlusion of the IRA. In the remaining eight patients with patent artery, an improvement in response to ACh was observed relative to the initial study (+3 +/- 11%, vs. -19 +/- 15%, p < 0.05).
Conclusions:
In patients with AMI treated with thrombolysis, severe endothelial dysfunction in the IRA is observed early. In patients who retain patency of the IRA, the endothelial dysfunction improves during the follow-up and suggests a component of stunned endothelium in the first few days post-AMI.