Risks of outpatient angiography and interventional procedures: a prospective study

The purpose of this study was to evaluate complications in diagnostic and interventional angiographic procedures performed on outpatients.

Data were collected prospectively for 2,683 procedures performed on an outpatient basis in 2,248 patients from the period March 1997 to March 2002. Patients were assessed by nursing or medical staff within 2-4 hr of the procedure and again via telephone 24-48 hr after the procedure. The collected data were summarized on the basis of procedure type into four main groupings: aortofemoral studies, cerebral studies, interventional procedures, and other studies. Complication frequency distribution was determined for each procedure type. An interim summary of complication rates was prepared for the period March 1997 to June 1999. Statistical analysis using a two-tailed z-test for the comparison of two proportions was performed to determine if a significant difference existed in the rates of complications from data collected before and after the June 1999 summary.

Ninety-one percent of cases completed follow-up. In total, 561 complications were identified in 2,436 cases (23%). Most complications consisted of either local pain or puncture site hematoma and bruising. No deaths occurred. In the 1,128 diagnostic aortofemoral studies performed, 211 complications (19%) occurred. In the 359 cerebral studies, 87 complications (24%) occurred. The 441 interventional procedures resulted in 146 complications (33%). In the remaining 508 procedures, 117 complications (23%) occurred. Major complications in each group are presented.

We observed a low incidence of complications requiring further treatment or resulting in a permanent deficit. The rates are comparable to published data from similar studies and practice standards guidelines. A statistically significant improvement was seen in the total complication rate between the periods March 1997-June 1999 and July 1999-March 2002 (p = 0.01).