Related Experiment Videos
Patency and reinfarction in late-entry myocardial infarct patients treated with reperfusion therapy
A W van 't Hof1, F Zijlstra, M J de Boer
1Department of Cardiology, Ziekenhuis de Weezenlanden, Zwolle, The Netherlands.
Insights
Timely reperfusion therapy for acute myocardial infarction (AMI) improves infarct vessel patency and reduces recurrent heart attacks. Late treatment (after six hours) is linked to poorer outcomes and blocked arteries.
Area of Science:
- Cardiology
- Interventional Cardiology
Background:
- Patency of the infarct-related artery post-acute myocardial infarction (AMI) correlates with improved long-term patient prognosis.
- While early reperfusion therapy demonstrates high infarct vessel patency, data on late-presenting patients are less extensive.
Purpose of the Study:
- To determine the relationship between the timing of reperfusion therapy and infarct-related vessel patency.
- To investigate the impact of reperfusion timing on clinical outcomes in AMI patients.
Main Methods:
- A comparative study involving 268 patients treated within six hours of AMI symptom onset (Early group) and 33 patients treated after six hours (Late group).
- Follow-up coronary angiography, performed in 95% of patients after a mean of 48 days, assessed infarct-related vessel patency using the Thrombolysis in Myocardial Infarction (TIMI) flow classification.
- Vessel occlusion was defined as TIMI flow grade 0 or 1.
Main Results:
- The infarct-related vessel was occluded in 41% of late-entry patients versus 17% of early-entry patients (P = 0.01).
- Late reperfusion was associated with a significantly higher rate of recurrent myocardial infarction (27% vs. 9%, P = 0.005).
- Relative risk for vessel occlusion was 2.50 (95% CI: 1.26 to 6.83) and for recurrent MI was 2.94 (95% CI: 1.50 to 5.81) in the late group.
Conclusions:
- Late reperfusion therapy (after six hours) for acute myocardial infarction is associated with reduced infarct vessel patency.
- Patients receiving late reperfusion therapy exhibit a higher incidence of recurrent myocardial infarction compared to those treated early.
Abstract:
Patency of the infarct-related vessel is associated with a more favorable long-term prognosis after acute myocardial infarction (AMI). High infarct vessel patency is reported for early reperfusion therapy, but data on patency and its possible effect on clinical outcome are less abundant for patients presenting late after the acute event. The aim of this study was to investigate whether time to reperfusion is related to infarct-vessel patency and clinical outcome. This study compares 268 patients who presented with symptoms of AMI within six hours after the onset of symptoms (Early) with 33 patients who had reperfusion therapy for signs of ongoing ischemia more than six hours after the start of chest pain (Late). At follow-up coronary angiography, flow through the infarct-related vessel was assessed according to the thrombolysis in myocardial infarction (TIMI) classification. Vessels were considered occluded if TIMI flow grade 0 or 1 was present. Follow-up angiography was performed in 95% of patients after a mean of forty-eight days. The infarct-related vessel was occluded in 41% of the late-entry patients (13 of 32), and in 17% of those presenting early (44 of 252), (P = 0.01; relative risk [RR]: 2.50; 95% confidence interval [CI]: 1.26 to 6.83). This was associated with a higher rate of recurrent myocardial infarction in late-entry patients: 27% (9 of 33), compared with 9% (25 of 268) in the early group (P = 0.005; RR: 2.94; 95% CI: 1.50 to 5.81). Thus, in the present study, late reperfusion therapy (after six hours) was associated with a higher recurrent myocardial infarction rate and a lower infarct vessel patency rate, compared with early treatment of patients.