“How serious is angioplasty surgery?”

Technically, angioplasty involves dilating the blood vessels and putting a guide wire to keep it open. Are we talking about angioplasty of the coronary arteries or the leg arteries? That is not clear from the question. It is a simple procedure, but the risk of complications is always there. A surgeon is always around to take care of any possible unintended mishaps.

I assume you are referring to coronary balloon angioplasty with stent placement. It should be safe. There are several factors. How bad the coronary artery lesion is, etc. Experience of the invasive cardiologist should be considered as well.