Nobody has tested whether NAD supplements affect the heart
Both precursors raise 2PY and 4PY, breakdown products that in cardiac patients carried 1.6 to 2.0 times the rate of heart attack and stroke. No trial has joined the two.
What the study found
No NAD precursor trial has ever measured a heart attack
Nicotinamide mononucleotide and nicotinamide riboside both raise 2PY and 4PY, end products of niacin breakdown. In cardiac patients on no supplement, higher levels of the two carried 1.6 to 2.0 times the three-year rate of heart attack, stroke and cardiac death. No trial has joined them.
The caveat · Heart patients, not supplement users
The cohorts were stable cardiac patients, not supplement users, so the absolute risk does not transfer to anyone taking a capsule. The human half is observational, though 4PY at physiological levels switched on the vascular inflammation machinery in mice and a genetic analysis across 106,000 people pointed the same way. Every trial of these supplements that measured the metabolites ran weeks to months, far too short for a heart attack to be an endpoint.
What we don't know
The cohorts were stable cardiac patients, not supplement users, so the absolute risk does not transfer to anyone taking a capsule. The human half is observational, though 4PY at physiological levels switched on the vascular inflammation machinery in mice and a genetic analysis across 106,000 people pointed the same way. Every trial of these supplements that measured the metabolites ran weeks to months, far too short for a heart attack to be an endpoint.