Objective: Assessment of the relationship between changes in sequential coronary arteriograms and subsequent clinical coronary events.
Design: The Program on the Surgical Control of the Hyperlipidemias, a randomized secondary atherosclerosis intervention trial, obtained coronary arteriograms at baseline, 3, 5, and 7 or 10 years of follow-up. Assessments of changes between pairs of coronary arteriograms were made by two-member panels blinded to the patients' assigned treatment and to the temporal sequence of the films. The relationship of changes between the baseline and the 3-year follow-up arteriograms and subsequent clinical coronary events was examined.
Setting: Three university hospitals and one private primary care facility.
Patients: A total of 838 patients, with 417 patients randomized to the control group and 421 to the intervention group. Of all patients, 695 had baseline and 3-year arteriograms.
Intervention: The control group received American Heart Association Phase II diet instruction and the intervention group received identical dietary instruction plus a partial ileal bypass operation.
Main outcome measure: The use of arteriographic changes as a predictor of subsequent clinical coronary events.
Results: Changes between the baseline and the 3-year coronary arteriographic overall disease assessment were significantly associated with subsequent overall and atherosclerotic coronary heart disease mortality (P less than .01). For the combined end point of atherosclerotic coronary heart disease mortality or confirmed nonfatal myocardial infarction, a significant relationship between the overall disease assessment and subsequent clinical events was found in the control group (P less than .0001) and in the surgery group (P = .04). For this combined end point, however, the control and the surgery groups were different with respect to clinical coronary events after 3 years, stratified by the baseline to 3-year overall disease assessment (P less than .001, unadjusted; P = .06, adjusted for 3-year clinical covariates).
Conclusions: Coronary arteriographic changes can be used in atherosclerosis intervention trials as a limited surrogate end point for certain clinical coronary events. This relationship is statistically compelling for overall mortality and atherosclerotic coronary heart disease mortality. For an individual patient, changes in the severity of coronary atherosclerosis seen on sequential coronary arteriograms can serve as prognostic indicators for subsequent overall or atherosclerotic coronary heart disease mortality.