It is always your choice not to have this procedure. But, it is important to understand the possible consequences involved with this decision. Although each individual situation is different, a heart condition left untreated can often lead to serious health problems.
If you decline the procedure, your doctor can provide you with medicine and therapy based on your heart's condition, other tests and observations. With certain heart problems medication is NOT enough to keep your condition from getting worse and prevent stroke, heart attack, or even death.
The final decision to have or not have this procedure rests with you, but all of your concerns related to this decision should be discussed with your doctor.