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Importance of angina for development of collateral circulation
Insights
Myocardial ischemia promotes collateral circulation development in humans. Pre-existing angina, a sign of ischemia, correlated with better collateral channels after acute myocardial infarction treatment.
Area of Science:
- Cardiology
- Vascular Biology
Background:
- Collateral circulation is crucial for myocardial reperfusion during acute myocardial infarction.
- Understanding factors influencing collateral development is vital for improving patient outcomes.
Purpose of the Study:
- To evaluate the extent of collateral circulation in patients treated with intracoronary thrombolysis for acute myocardial infarction.
- To investigate the relationship between pre-infarction angina and collateral development.
- To assess the influence of coronary vessel disease extent on collateralization.
Main Methods:
- Coronary cineangiography was used to grade collateral development (collateral index 0-3) in 46 patients.
- Patients with prior myocardial infarction or spontaneous recanalization were excluded.
- Angina history (pre-infarction) was recorded.
Main Results:
- Collateral channels were more frequently visible in patients with pre-infarction angina (9/18) compared to those without (2/19).
- The extent of coronary vessel disease did not significantly impact angina prevalence or collateral index.
- Myocardial ischemia appears to be a key factor in promoting collateral development.
Conclusions:
- Myocardial ischemia plays a significant role in promoting collateral circulation development in humans.
- Pre-infarction angina is associated with enhanced collateralization, suggesting its protective role.
- Further research into ischemia-driven collateralization may reveal new therapeutic targets.
Abstract:
The extent of collateral circulation in 46 patients who had intracoronary thrombolysis within six hours of the onset of acute myocardial infarction was evaluated. Patients who had had a previous myocardial infarction (4 cases) or who had spontaneously recanalized infarct related coronary arteries (5 cases) were excluded from the analysis. Collateral development was graded during coronary cineangiography according to the extent of opacification of the collateral and epicardial arteries distal to the site of occlusion (collateral index 0 to 3). Angina was considered to be present before myocardial infarction if it had occurred more than one week before acute myocardial infarction. Collateral channels were visible in only two of 19 patients without angina before infarction and nine of the 18 patients with angina before infarction. The prevalence of angina and the collateral index were not significantly influenced by the extent of coronary vessel disease. It is concluded that myocardial ischaemia is important in promoting collateral development in man as well as in laboratory animals.