abstract
- BACKGROUND: Studies conducted before 1999 of patients who had coronary artery bypass graft surgery (CABG) have shown a tendency toward increasing preoperative risk factors. This study examines whether this trend of increasing risk in patients who have cardiac surgery has continued since 1999 and whether its effect on mortality and morbidity has changed. METHODS: We prospectively collected data for 2754 patients who had cardiac surgery, divided them into 4 cohorts based on the year of operation (2000-2003) and analyzed the data according to 56 predefined preoperative, operative and postoperative variables. RESULTS: There were no significant changes in most preoperative risk factors over time, except for significant decreases in the proportion of elective (p = 0.016) and emergency/salvage operations (p < 0.001) and increases in urgent procedures and in the number of patients with congestive heart failure (CHF) (p < 0.001). The proportion of CABG procedures decreased significantly, whereas the proportion of valve, CABG plus valve, and non-CABG surgeries increased. A significant increase in multiarterial graft use and a decrease in off-pump coronary artery bypass procedures were observed. Postoperative complication rates did not change during the 4 years except for a significant decrease in wound infections. No significant changes in overall mortality and mortality across types of procedure were observed. Median observed/expected ratios for expected length of stay in hospital and risk of mortality did not change significantly over time. CONCLUSION: Patients' risk factors, except for CHF, did not change from 2000 to 2003. Despite more complicated procedures, the postoperative complication rates did not change except for a decrease in wound infections. These results suggest that the assumption of an inexorably increasing patient risk profile should be re-evaluated.