The naproxen could have been a "trigger." The 50% atheroma has probably took a little longer to build up.
NSAID's (Ibuprofen/Naproxen/Diclofenac) work very well, but do result in lowering of kidney function and increased BP.
It's a difficult call,they do work very well,(being awake all night with knee pain is also dangerous to the body,) but NSAID's are associated with increased risk of CHS/CVA/Kidney Disease. There is a "ladder" of risk, probably in the order I've highlighted.
I hope your feeling okay, and recovery is uneventful.