BACKGROUND: Despite advancements in peri-operative care and conflicting evidence regarding the need for preoperative coronary revascularization, the optimal timing of noncardiac surgery (NCS) following cardiac operations remains unclear. OBJECTIVES: The purpose of this study was to evaluate the effect of time interval between cardiac surgery and NCS on peri-operative risk of major adverse events (MAEs). METHODS: Adults undergoing elective CABG, valve repair or replacement, or combined procedures were identified in the 2016 to 2020 Nationwide Readmissions Database, with subsequent admission for NCS analyzed. The time interval in between NCS and index cardiac operations was modeled using restricted cubic splines, and clinical outcome differences were evaluated across various NCS risk and urgency categories. RESULTS: Of 1,335,175 patients undergoing cardiac surgery, 20,253 (1.5%) required a subsequent NCS. On risk-adjusted examination of MAE rates as a function of time delay after cardiac surgery, an inflection point was noted at 100 days postoperatively. Based on this threshold, 47.9% of patients who had NCS within 100 days were considered early while others were grouped as late. Late NCS was associated with significantly lower odds of MAE (adjusted OR: 0.69
95% CI: 0.62-0.76), and in-hospital mortality (adjusted OR: 0.66
95% CI: 0.46-0.96), as compared to early NCS. This relationship persisted across all cardiac surgical subgroups and whether subsequent NCS was elective. Additionally, nonelective procedures classically categorized as low risk in the general population, exhibited comparable rates of MAE to high-risk procedures following early NCS. CONCLUSIONS: When feasible, delaying NCS, particularly beyond 100 days, appears to be associated with a reduction in adverse events, suggesting a potential opportunity for optimization of patient outcomes.