for the Post CABG Clinical Trial Investigators
The frequent use of diagnostic coronary arteriography and its importance in evaluating results of intervention in clinical trials emphasize the necessity of continued assessment of procedural risk. Several studies have described such risks, but they have often included a diverse group of patients with varying levels of clinical stability. Furthermore, this risk has not been well established in a population of patients with saphenous vein bypass grafts. There is need to define the risk of coronary arteriography in a group of patients who are both clinically similar and stable, and to evaluate the influence of improved technology and increased operator experience on the risk of the procedure. The National Heart, Lung, and Blood Institute-funded Post Coronary Artery Bypass Graft Trial offered the opportunity to evaluate the risk of elective diagnostic coronary arteriography in clinically stable patients studied at two points in time: pre-enrollment and 4-5 years after study entry. In this group of 2,635 angiograms from clinically stable patients over 5 years there were no deaths and the risk of myocardial infarction was 0.08%, while 0.7% had clinically important complications. Non-elective, urgent studies (311 angiograms) on unstable patients were more likely to include angioplasty and were associated with a risk of death of 0.6% and myocardial infarction of 1.3%. Complications did not vary with age or gender. Vascular trauma was more likely to occur using the brachial than the femoral artery entry sites. These results indicate that elective angiography on stable patients can be accomplished with a very low risk of mortality (0% in this study) or serious cardiovascular complication. This supports the safety and usefulness of angiography for clinical intervention trials. Cathet.