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Updated: May 2, 2026
Postconditioning with Lactate-enriched Blood for Cardioprotection in ST-segment Elevation Myocardial Infarction
Published on: May 28, 2019
No post-conditioning in the human heart with thrombolysis in myocardial infarction flow 2-3 on admission
F Roubille1, N Mewton2, M Elbaz3
1Department of Cardiology, UMR5203, UMR661, Institut de Génomique Fonctionnelle, Universités Montpellier 1 and 2, Montpellier, France Montreal Heart Institute, Université de Montréal, Montreal, QC, Canada H3T 1J4.
Insights
Mechanical ischemic post-conditioning (PostC) did not reduce infarct size in ST-elevation myocardial infarction patients with TIMI 2-3 flow. This suggests the timing of PostC intervention is critical for preventing reperfusion injury.
Area of Science:
- Cardiology
- Interventional Cardiology
- Myocardial Infarction Research
Background:
- Mechanical ischemic post-conditioning (PostC) shows promise in reducing infarct size in ST-elevation myocardial infarction (STEMI) patients with initial poor coronary flow (TIMI 0-1).
- The efficacy of PostC in STEMI patients with better initial coronary flow (TIMI 2-3) remains unclear, especially regarding delayed application.
Purpose of the Study:
- To investigate the effectiveness of mechanical ischemic post-conditioning (PostC) in reducing infarct size in STEMI patients with TIMI 2-3 flow at admission.
- To determine if the timing of PostC intervention influences its protective effect against reperfusion injury.
Main Methods:
- A multi-center, randomized, single-blinded study involving 99 STEMI patients with TIMI 2-3 flow.
- Patients underwent direct stenting, followed by either PostC (four cycles of balloon inflation/deflation) or standard care (control group).
- Infarct size was assessed by cardiac magnetic resonance imaging (CMR) at Day 5 and by cardiac enzyme release (creatine kinase, troponin I).
Main Results:
- Despite comparable areas at risk and time to intervention, PostC did not significantly reduce infarct size as measured by CMR (23 ± 17 g vs. 21 ± 18 g, P=0.64).
- Analysis of cardiac enzyme release also showed no significant difference between the PostC and control groups, even after adjusting for the area at risk.
- Baseline characteristics and procedural parameters were similar between the groups.
Conclusions:
- Mechanical ischemic PostC is ineffective in reducing infarct size when applied to STEMI patients with TIMI 2-3 flow at admission.
- The timing of the PostC intervention relative to reperfusion onset is a crucial factor determining its efficacy in mitigating lethal reperfusion injury.
Aims:
Proof-of-concept evidence suggests that mechanical ischaemic post-conditioning (PostC) reduces infarct size when applied immediately after culprit coronary artery re-opening in ST-elevation myocardial infarction (STEMI) patients with thrombolysis in myocardial infarction 0-1 (TIMI 0-1) flow grade at admission. Whether PostC might also be protective in patients with a TIMI 2-3 flow grade on admission (corresponding to a delayed application of the post-conditioning algorithm) remains undetermined.
Methods And Results:
In this multi-centre, randomized, single-blinded, controlled study, STEMI patients with a 2-3 TIMI coronary flow grade at admission underwent direct stenting of the culprit lesion, followed (PostC group) or not (control group) by four cycles of (1 min inflation/1 min deflation) of the angioplasty balloon to trigger post-conditioning. Infarct size was assessed both by cardiac magnetic resonance at Day 5 (primary endpoint) and cardiac enzymes release (secondary endpoint). Ninety-nine patients were prospectively enrolled. Baseline characteristics were comparable between control and PostC groups. Despite comparable size of area at risk (AAR) (38 ± 12 vs. 38 ± 13% of the LV circumference, respectively, P = 0.89) and similar time from onset to intervention (249 ± 148 vs. 263 ± 209 min, respectively, P = 0.93) in the two groups, PostC did not significantly reduce cardiac magnetic resonance infarct size (23 ± 17 and 21 ± 18 g in the treated vs. control group, respectively, P = 0.64). Similar results were found when using creatine kinase and troponin I release, even after adjustment for the size of the AAR.
Conclusion:
This study shows that infarct size reduction by mechanical ischaemic PostC is lost when applied to patients with a TIMI 2-3 flow grade at admission. This indicates that the timing of the protective intervention with respect to the onset of reperfusion is a key factor for preventing lethal reperfusion injury in STEMI patients.
Clinical Trial Number:
NCT01483755.
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