He cancelled the stress test that was scheduled for Friday morning.
This is what I want to do. I want to type up a document for him to sign, stating that (1) he understands that his doctor wants him to have a stress test to rule out heart problems in view of discomfort he has had in his chest; (2) he refuses the stress test; (3) he understands that there is a possibility that heart problems may go undiagnosed because of this refusal; (4) he understands that any medical treatment for chest discomfort will be obtained at his own expense; (5) he releases the doctor from all responsibility for any harm that may come to him as a result of his refusing the test; and (6) he releases his wife from all responsibility for any harm that may come to him if he experiences chest discomfort but does not seek medical treatment because he does not want to have to pay for it. I would keep one copy of this document and give the other to the GP for his medical records.
At least that would be honest. If he wants to refuse the procedure, just say so. Don't keep everyone dangling with this "now I will, now I won't" game.