Key result
Resuscitated cardiac arrest reduces LVEF by ~19 percentage points acutely, marked by transient myocardial inflammation.
Why the study?
Myocardial dysfunction after cardiac arrest contributes to poor outcomes, but the underlying myocardial inflammatory mechanisms and the relative contributions of ischemia-reperfusion versus adrenaline remain incompletely defined.
Does ischemia-reperfusion injury following cardiac arrest and resuscitation elicit a distinct myocardial inflammatory response and functional decline compared to adrenaline exposure alone?
Does ischemia-reperfusion injury following cardiac arrest and resuscitation elicit a distinct myocardial inflammatory response and functional decline compared to adrenaline exposure alone?
Absolute Event Rate: 44.2% vs 63.1%
p-value: p=<0.0005
Cardiac arrest induces a distinct, self-limited myocardial inflammatory cascade characterized by acute neutrophil infiltration and cytokine surges that parallels transient functional cardiac decline, identifying a narrow therapeutic window for immunomodulation.
Transient post-arrest EF decline in mice may reflect self-limited inflammation; leaves open immunomodulatory targets for human cardiac arrest.
Background: Myocardial dysfunction after cardiac arrest (CA) is a major contributor to poor outcomes, yet the underlying inflammatory mechanisms within cardiac tissue remain incompletely defined. We sought to delineate the temporal evolution of myocardial inflammation following CA, distinguishing the effects of ischemia-reperfusion injury from those of adrenaline exposure alone. Methods and Results: Using a murine model of CA and resuscitation, we profiled transcriptomic, immunologic, and functional cardiac changes in mice exposed to either CA followed by resuscitation with adrenaline (Arrest group), adrenaline alone (Adr group), or anesthesia alone (Naïve group). Animals were assessed at 0.5-, 1-, 3-, and 7-days via echocardiography, RNA-sequencing, flow cytometry, immunohistochemistry, and multiplex cytokine analysis. CA elicited a robust, early myocardial inflammatory response characterized by neutrophil infiltration, systemic cytokine surges (IL-6, TNF-α, IL-1β), and downregulation of mitochondrial and metabolic pathways. This immune activation peaked at 0.5 days and resolved by day 7, coinciding with transient myocardial dysfunction and recovery of ejection fraction. In contrast, adrenaline alone induced a delayed, attenuated response peaking at 1 day. Transcriptomic and immunophenotypic signatures distinguished ischemia-driven injury from catecholaminergic effects. Conclusions: CA induces a distinct, self-limited myocardial inflammatory cascade that parallels functional cardiac recovery. These findings identify a narrow therapeutic window for immunomodulatory interventions and provide a mechanistic foundation for targeted therapies to mitigate cardiac injury after resuscitation.
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Panigrahi et al. (2025) studied Cardiac arrest and myocardial inflammation (n=62). Cardiac arrest and resuscitation with adrenaline vs. Anesthesia alone (Naïve) or Adrenaline alone was evaluated on Ejection fraction at 0.5 days post-resuscitation (p=<0.0005). Cardiac arrest and resuscitation with adrenaline in a murine model significantly reduced ejection fraction at 0.5 days to 44.2% compared to 63.1% in naive mice (p<0.0005), coinciding with transient acute myocardial inflammation.
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