Related Experiment Videos
[Collaterals do not prevent infarcts in subacute vascular stenosis following initially successful vascular stent
Insights
Collateral circulation, while protective in coronary artery stenosis, cannot be rapidly recruited to prevent myocardial infarction during subacute stent thrombosis. This finding contrasts with previous animal study results.
Area of Science:
- Cardiovascular Medicine
- Interventional Cardiology
- Clinical Research
Context:
- Coronary artery stenosis management often involves stenting to restore blood flow.
- The role of collateral circulation in preventing myocardial infarction during acute or subacute coronary events is crucial.
- Previous animal studies suggested rapid collateral recruitment is possible.
Purpose:
- To investigate if regressed collateral circulation can be quickly reactivated to prevent myocardial infarction in patients experiencing subacute stent thrombosis.
- To compare human responses to collateral recruitment with findings from animal models.
Summary:
- A retrospective study of 50 patients with high-grade coronary artery stenosis who underwent stenting was conducted.
- Seven patients developed subacute stent thrombosis, and six of them experienced myocardial infarction.
- Despite the presence of collateral circulation, it was insufficient to prevent myocardial necrosis in these cases.
Impact:
- This study demonstrates that collateral circulation, once regressed after restored blood flow, cannot be recruited quickly enough in humans to prevent myocardial necrosis during subacute coronary artery occlusion.
- Findings challenge previous assumptions based on animal studies regarding the rapid functional capacity of collateral networks in humans.
- Highlights potential limitations of relying solely on collateral circulation for protection against thrombotic events post-stenting.
Unlabelled:
Sufficient collateralization may prevent acute myocardial infarction despite complete obstruction of a coronary artery. Nevertheless, it is unclear if collaterals which regressed after restoration of antegrade flow may be recruited fast enough to prevent myocardial infarction in case of subacute coronary artery thrombosis. In 50 patients (pts) (48 males, two females, age 60 +/- 7.6 years) with high-grade coronary artery stenosis and collaterals from the contralateral non-diseased coronary artery, stenting devices (Palmaz-Schatz) were implanted. In seven patients subacute thrombosis of the stent occurred. Six patients developed myocardial infarcts with a CKmax greater than 100 U/l (mean 943 +/- 635 U/l). One patient was treated by intravenous thrombolysis, three pts with acute PTCA, one patient with both, and one patient had CABG after unsuccessful PTCA; no patient died. There was no statistical correlation to the degree of collateralization and time after, or location of stent implantation, most likely because of the small number of cases.
Conclusion:
This retrospective study shows that collaterals in humans with a high-grade coronary artery stenosis which has regressed after restoration of sufficient antegrade blood-flow cannot be recruited fast enough to prevent myocardial necrosis in case of subacute coronary artery occlusion. This is in contrast to earlier results obtained in animal studies.