Coronary angiography and its complications. The search for risk factors

Previous efforts to define risk factors associated with coronary angiography have generally focused on only one or two potential candidates. These elements are often found by exploring data sets for relationships not generally specified in advance. We attempted to determine whether 14 factors were associated with increased risk in 995 patients undergoing angiocardiography in five medical centers. The study found a consistently increased risk for women, for patients having lengthier procedures, and for patients studied at one of the five centers. No evidence of increased risk was found for 11 other factors, including two related to operator experience. Data exploration ("data mining") was also undertaken, using sequential multiple logistic regression analyses. A strong risk of complications, not previously observed or hypothesized in advance, was noted for vascular complications in women studied by the brachial technique.