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Reocclusion: the flip side of coronary thrombolysis
F W Verheugt1, A Meijer, W K Lagrand
1Department of Cardiology, University Hospital Nijmegen St. Radboud, Nijmegen, The Netherlands.
Insights
Coronary artery reocclusion after thrombolytic therapy for acute myocardial infarction occurs in 11% of cases, particularly in the early weeks. Proven initial artery occlusion is a risk factor, necessitating the development of safe prevention strategies.
Area of Science:
- Cardiology
- Interventional Cardiology
- Thrombolytic Therapy
Background:
- Coronary artery reocclusion is a significant complication following thrombolytic therapy for acute myocardial infarction.
- Predicting, diagnosing, and preventing reocclusion are critical areas of research.
Purpose of the Study:
- To analyze the incidence and predictors of coronary artery reocclusion after thrombolytic therapy.
- To evaluate the effectiveness of current strategies in preventing reocclusion.
Main Methods:
- Systematic review and meta-analysis of 61 studies involving 6,061 patients with at least two angiograms.
- Comparison of reocclusion rates between studies using three angiograms versus two angiograms.
Main Results:
- Overall reocclusion rate was 11% (666/6,061 patients).
- True reocclusion studies (3 angiograms) showed a higher incidence (16% +/- 10%) compared to studies with two angiograms (10% +/- 8%).
- Initial occlusion of the infarct-related artery, residual stenosis, and flow state post-lysis are potential predictors.
Conclusions:
- Reocclusion is an early complication, most frequent in the initial weeks post-thrombolysis.
- Proven initial artery occlusion is a risk factor for reocclusion.
- Further research is needed to develop safe and effective prevention strategies.
Abstract:
Since the introduction of thrombolytic therapy for acute myocardial infarction, the incidence of coronary artery reocclusion has been intensively studied. Also, the prediction and diagnosis of reocclusion by angiographic and clinical variables, as well its invasive and pharmacologic prevention, have gained much attention. By angiographic definition, reocclusion requires three angiographic observations: one with an occluded artery, one with a reperfused artery and a third for the assessment of subsequent occlusion (true reocclusion). Since the introduction of early intravenous reperfusion therapy, most studies use only two angiograms: one with a patent and one with a nonpatent infarct-related artery. A search for all published reocclusion studies revealed 61 studies (6,061 patients) with at least two angiograms. The median time interval between the first angiogram after thrombolysis and the second was 16 days (range 0.1 to 365). Reocclusion was observed in 666 (11%) of 6,061 cases. Interestingly, the 28 true reocclusion studies showed an incidence of reocclusion of 16 +/- 10% (mean +/- SD), and the 33 studies with only two angiograms 10 +/- 8% (p=0.04), suggesting that proven initial occlusion of the infarct-related artery is a risk factor for reocclusion after successful thrombolysis. The other predictors for reocclusion are probably severity of residual stenosis of the infarct-related artery after thrombolysis and perhaps the flow state after lysis. Reocclusion is most frequently seen in the early weeks after thrombolysis. The clinical course in patients with reocclusion is more complicated than in those without this complication. Left ventricular contractile recovery after thrombolysis is hampered by reocclusion. Routine invasive strategies have not been proven effective against reocclusion. In the prevention of reocclusion, both antiplatelet and antithrombin strategies have been tested, including hirudin and hirulog, but the safety of these agents in thrombolysis is still questionable. Thus, reocclusion after thrombolysis is an early phenomenon and is more frequent after proven initial occlusion of the infarct-related artery. Reocclusion can be predicted by angiography after thrombolysis. Because reocclusion is detrimental, strategies to prevent it should be developed and carried out after thrombolytic therapy for acute myocardial infarction as soon as they are deemed safe.