My Husband Had 2 Stents Placed 3 Months Ago, 1

my husband had 2 stents placed 3 months ago, 1 inside a previous stent. After surgery he did very well until three weeks ago when he became extremely fatigued, coloring grey. Cardiologist finally gave him appt and did some blood work. Not much has changed and tiredness continues I am concerned that stents are not working, but I am the only one