Your age and general condition before the cardiac catheterization and placing of the stent would be factors in understanding your kidney condition. Cardiac catheterization is generally remarkably safe and under ordinary circumstances should not lead to kidney problems.
As I am sure you realize, I am unable to diagnosis your kidney status online. However, it might be worthwhile for you or your family physician to contact the doctor who did the cardiac catheterization and placed the stent at the time you had the heart attack to determine if there was any unusual occurrence.