Cardiac Opioid System Modulates Heart Function, Showing Dual Roles in Ischemia-Reperfusion and Heart Failure

The heart possesses a local cardiac opioid system comprising receptors and endogenous peptides that modulate cardiac and vascular function, independent of central nervous system effects. Understanding this local system is crucial, as its role in cardiovascular disease and perioperative medicine is complex and often contradictory. While opioids have shown promise for ischemia-reperfusion injury, their administration in heart failure has been linked to adverse outcomes, highlighting a critical gap in understanding these differential effects and their clinical implications.

This comprehensive review synthesized existing literature on the cardiac opioid system, focusing on its components (opioid receptors and peptides) and their functional roles. The authors systematically examined preclinical and clinical evidence regarding the system's involvement in ischemia-reperfusion injury and heart failure. The review aimed to highlight mechanistic insights into how the cardiac opioid system's function differs across these distinct pathological states and to place these findings within a practical clinical context, particularly concerning perioperative opioid use.

The review revealed that the local cardiac opioid system acts as a significant modulator of cardiac and vascular function. In the context of ischemia-reperfusion injury, opioids have consistently been associated with cardioprotective effects in preclinical models, suggesting a beneficial role in mitigating damage. However, a contrasting picture emerged for heart failure, where opioid administration has been linked to adverse clinical outcomes. This includes:

higher in-hospital mortality and an increased need for ventilatory support in patients with heart failure receiving opioids. These findings underscore that the functional effects of the cardiac opioid system are highly context-dependent, with distinct implications for different cardiovascular pathologies. The review emphasizes that opioid effects on cardiac function and hemodynamic regulation are particularly relevant and complex in heart failure.