What would be the source of chest pain after stents throughtout the whole year after this was done?

HAd thick blood blockages found during cath and have 5 stents. Cholesterol is perfect 150. Pain eases up but then gets bad again.

Cardiologist is  well aware of this but insists its not heart related. Ekg shows nothing and blood pressure is perfect. Lungs are clear. Had chest xray and that was good as well. Heart beats are steady.