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Updated: Jun 6, 2025
Histological Quantification of Chronic Myocardial Infarct in Rats
Published on: December 11, 2016
Effect of ventricular fibrillation on infarct size after myocardial infarction: a translational study
Neven Stevic1,2,3, Alexandre Pinède1, Nathan Mewton2,3,4
1Service de Médecine Intensive -Réanimation, Hospices Civils de Lyon, Hôpital Edouard Herriot, 5 Place d'Arsonval, 69437, Lyon Cedex 03, France.
Insights
Ventricular fibrillation (VF) occurring before reperfusion in ST-segment elevation myocardial infarction (STEMI) was linked to smaller infarct sizes in patients and animal models. However, this did not translate to reduced long-term infarct scar size.
Area of Science:
- Cardiovascular Medicine
- Cardiac Electrophysiology
- Myocardial Infarction Research
Background:
- Ventricular fibrillation (VF)-induced cardiac arrest is a common complication of ST-segment elevation myocardial infarction (STEMI).
- While larger infarct sizes (IS) increase VF risk, the impact of VF on IS is not well understood.
- Investigating this relationship is crucial for understanding STEMI pathophysiology and treatment.
Purpose of the Study:
- To determine the effect of VF on infarct size (IS) in STEMI patients and experimental models.
- To analyze if VF occurring before reperfusion influences the extent of myocardial damage.
- To assess the long-term consequences of VF on infarct scar size.
Main Methods:
- A prospective cohort study matched 30 STEMI patients with VF to 60 without VF based on common IS determinants.
- Infarct size was assessed using 48-hour troponin AUC.
- Experimental models included pigs and isolated rat hearts undergoing STEMI with and without VF.
Main Results:
- Matched STEMI patients with VF showed a 33% smaller IS compared to controls (p < 0.05).
- Both pig and rat models demonstrated a smaller IS as a percentage of the area at risk (AR) in the VF groups (p < 0.05).
- No significant difference in infarct scar size was observed between VF and control groups at 1 and 6 months post-MI.
Conclusions:
- VF occurring prior to myocardial infarction reperfusion is associated with smaller acute infarct sizes when key determinants are comparable.
- This protective effect on acute infarct size was not associated with reduced long-term infarct scar size.
- Findings were observed in a selected patient group and specific experimental conditions, warranting further investigation.
Abstract:
Ventricular fibrillation (VF)-induced cardiac arrest frequently complicates ST-segment elevation myocardial infarction (STEMI). Although larger infarct sizes (IS) correlate with a higher risk of VF, the influence of VF itself on IS has remained poorly investigated. To address this knowledge gap, we analyzed the effect of VF on IS in patients and two experimental models. From a prospective cohort, 30 STEMI patients with VF were matched 1:2 with STEMI patients without VF on the common determinants of IS. The primary endpoint was IS, assessed using the 48-h area under the curve (AUC) for troponin. We also compared IS in pigs with/without spontaneous VF during STEMI (n = 15/group), and in an isolated rat heart model of myocardial infarction with/without electrically induced VF (n = 7/group). After matching, the patient characteristics, including the area at risk (AR), were similar. IS was 33% lower in the VF group compared to the control group (troponin AUC 1.6 [0.5-3.3] 106 arbitrary units vs. 2.4 [0.9-4.1] 106 arbitrary units; p < 0.05), but infarct scar size (assessed using MRI and ECG) did not differ between the groups at 1 and 6 months. In both experimental models, IS, expressed as a percentage of AR, was lower (p < 0.05) in the VF group than in the control group. When common determinants of IS are comparable, VF occurring prior to myocardial infarction reperfusion appears to be associated with smaller IS. Nevertheless, this finding, observed under specific experimental conditions and in a highly selected group of patients, was not associated with reduced infarct scar size.Registration (HIBISCUS-STEMI cohort): ClinicalTrials.gov NCT05794022.
