My mother, age 70, is diabetic. She is scheduled for a catheter procedure to determine if she has a blockage in her heart. She has had ultrasound and EKG tests performed that indicate she may have a problem. Are there less invasive or non-invasive procedures that would provide the same or useful information at a lower risk level? I'm concerned because she is diabetic and this may add additional risk to the catheter procedure on top of the other know risks.