Cardiovascular complications after GI endoscopy: occurrence and risks in a large hospital system

Background. There is limited information concerning the risks for, and occurrence of, cardiovascular complications because of GI endoscopy. Published data are based on questionnaire surveys, which have a potential for bias. Moreover, available studies pertain exclusively to out-patients. Methods: In-patients and day-stay patients who incurred charges for endoscopy with endoscopic procedure coding from 1999 through 2001 were identified from a financial database for all 9 hospitals in a large health care system. From these patients, those considered "at risk" for cardiovascular complications were selected based on charges for cardioactive medications, cardiac enzyme determinations, or intensive care services on the day of or the day after endoscopy. Medical records were reviewed for 25% of these patients, selected at random, noting demographics, history, and a modified Goldman score in patients with cardiovascular complications (defined as arrhythmia, chest pain or anginal equivalent, hypotension or myocardial infarction occurring within 24 hours after endoscopy). Identical information was obtained from a random sample of 0.5% of the chart records for all patients undergoing endoscopy. Results: Patients who underwent endoscopy were not reliably identified for one hospital. This hospital was omitted from the calculation of the extrapolated rate of complication occurrence, but patients identified through chart review as having or not having a complication after endoscopy were included in the risk analysis. The extrapolated rate of occurrence of cardiovascular complications was 309: 95% CI [197, 457] per 100,000 procedures. Independent risk factors were: male gender, modified Goldman score, and use of propofol. Conclusions: In this study of patients undergoing hospital-based GI endoscopy, the risk of procedure-related cardiovascular complications was 2 to 70 times higher than previously reported. This finding may be ascribed to differences in the populations sampled and to a case-finding method that minimized reporting and ascertainment biases.