Heart failure and its treatment from the perspective of sympathetic nerve activity

Summary

Heart failure is the end-stage phenotype of several cardiac diseases. The number of heart failure patients is increasing in accordance with an increase in the number of elderly people. The prognosis of heart failure is poor and its 5-year death rate is comparable to that of stage III cancer. It is important to understand the essential mechanism of the worsening prognosis of heart failure and to practice effective treatment from the perspective of improving the prognosis of heart failure based on its essential mechanism. Plasma noradrenaline level is a good predictor of the survival rate of heart failure patients, and sympathetic nerve activity is augmented in patients with heart failure as evidenced by a higher noradrenaline release rate (spillover) from the sympathetic nerve endings especially in the heart and kidney. Noradrenaline release is regulated by presynaptic receptors at the sympathetic nerve endings, and the kidney affects the sympathetic nerve activity. Although the short-term reflex augmentation of sympathetic nerve activity caused by reduced cardiac function may help to improve cardiac function, long-term augmentation of sympathetic nerve activity damages the heart and deteriorates the prognosis of heart failure. Currently, drugs such as angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, β-blockers, mineralocorticoid antagonists, ivabradine, angiotensin receptor-neprilysin inhibitor, and sodium-glucose transport protein 2 inhibitors, are used for the treatment of heart failure, and had a good prognosis in large randomized, controlled clinical trials. Interestingly, the same characteristics in common of these drugs is the ability to optimize excessively augmented sympathetic nerve activity. This review discusses insights into essential mechanism of heart failure that determines the prognosis of heart failure, focusing on the interaction between sympathetic nerve activity and anti-heart failure drugs currently recommended by the 2021 guidelines of the Japanese Circulation Society and the Japanese Heart Failure Society for heart failure treatment.