Hello dear user! I have gone through your medical history carefully and understood your concerns. Having 80% blockage in the carotid arteries is a significant narrowing that may lead to complications and other problems in your health. Have you any disturbs or symptoms like weakness, blurred vision, dizziness, imbalance etc, in your everyday life? If yes I suggest you to consult your vascular surgeon and cardiologist as soon as possible to manage this issue carefully. Usually this condition requires an intervention doing angioplasty or endarterectomy of your carotids. Dipiridamol or warfarin is recommended to be taken continuously to prevent stroke. Regarding the stress test, I would say it must be done in critical care of doctors if you are asymptomatic, and I m afraid it can t be done if you are symptomatic. Please consult your cardiologist or hemodinamist before taking any procedures. I hope you will be fine and I wish you a good helath! Please kindly rate as helpful this answer. Thank you! DR ERIOL.