Is return of angina after coronary artery bypass grafting immutable, can it be delayed, and is it important?

Background: Because survival after either an operation or angioplasty is similar across a wide spectrum of coronary patients, lasting symptom relief assumes high priority.
Objectives: The objectives of this observational clinical study were (1) to determine whether the return of angina is immutable; (2) to identify factors that might delay its return, and (3) to evaluate whether its return is predictive of subsequent adverse events.
Methods: The return of angina of any degree of severity and morbid events subsequent to its return were studied by multivariable time-related analyses in a consecutive series of 9600 patients who were undergoing primary isolated coronary bypass operations between 1971 and 1992.
Results: The freedom rate from return of angina was 94%, 82%, 61% and 38% at 1, 5, 10, and 15 years. Increased modest risk of early return of angina was associated with preoperative demographic, symptom, coronary and vascular disease variables but reduced by more extensive arterial grafting. The ever-increasing risk of late return of angina was associated with demographic, symptomatic, left ventricular function, and coronary disease variables and was related strongly to comorbidity but was weakly reduced by controllable surgical variables. After the return of angina, 10-year freedom rate from infarct and survival was 71% and 68% respectively.
Conclusions: (1) The risk of angina return increases relentlessly after operation, so it is likely immutable. (2) Delay of late angina return by use of arterial grafting is clinically trivial; control of noncardiac comorbidity may be more effective. (3) Fortunately, the return of angina after coronary artery bypass grafting has minimal impact on survival and is not predictive of imminent infarct.