My husband had angioplasty back in 1996, it took effect immediately, and according to his cardiologist it’s still working.
However, they didn’t slice anything open except a small hole in his groin. They ran a tube up through his aorta to his heart and cleared things up there. He was awake during the procedure, although he had been given some good drugs to keep him calm and still. After the procedure he had to lie flat on his back for six hours so the incision would close up.
As to the effects – once they did the actual procedure he felt fine. No more angina, no more “heaviness” in his chest. He was just bored by having to lie still for so long.
Perhaps you are thinking of endarterectomy rather than angioplasty. The end results are similar but the method of getting there is different. This site explains it thusly:
“Endarterectomy involves opening the carotid artery, scooping out the fatty plaque, stitching up the artery, and then stitching together the skin of the neck. The main goal of the operation is to prevent a future stroke. Its biggest hitch is that it sometimes causes the problem it is being done to prevent. Even with the most experienced surgeon, the risk of a stroke is 1% to 2%.
Carotid angioplasty begins with a small incision over the femoral artery in the groin. A thin tube called a catheter is gently pushed into the artery and maneuvered into the narrowed carotid artery. Once in place, a balloon at the catheter’s tip is inflated, mashing the plaque into the artery wall and expanding a stent to hold open the artery. Like endarterectomy, it can cause strokes.”