One major cause of heart failure is what is known in the medical field as myocardial ischemia/reperfusion (I/R) injury — heart damage that occurs when blood flow to the heart stops (ischemia) and then restarts (reperfusion).
https://www.nmn.com/news/the-combination-of-melatonin-and-nmn-protects-the-aged-heart-from-injury
https://www.nmn.com/news/the-combination-of-melatonin-and-nmn-protects-the-aged-heart-from-injury