The prognostic impact of unplanned invasive coronary angiography following coronary artery bypass grafting

OBJECTIVES: Myocardial ischaemia following coronary artery bypass grafting (CABG) is a potentially devastating complication. Nevertheless, the incidence, aetiology, and prognostic relevance of unplanned CAG remain understudied. We aimed to investigate the prevalence and outcome of patients undergoing urgent, unplanned coronary angiography in the postoperative period following CABG. METHODS: We screened all patients undergoing isolated elective CABG in an academic referral centre between 2016-2021 and identified patients undergoing unplanned CAG (uCAG) within 30 days of surgery. Within uCAG patients, a distinction was made between patients undergoing re-revascularization (REV) and patients receiving conservative management (CON). The primary outcomes were 30-day mortality and unadjusted and adjusted long-term survival. Secondary outcomes were the indication for and prevalence of uCAG and urgent revascularization. RESULTS: Of the 1918 patients undergoing isolated CABG, 78 individuals needed uCAG (4.1%), of which 45 underwent immediate revascularization (REV-group; 2.3% overall, 57% within the uCAG group, median age 69.9 years) and 33 were treated conservatively (CON-group; 1.7% overall, 42% within the uCAG group, median age 69.1 years). Patients undergoing uCAG (n = 78) had a higher 30-day mortality than patients not undergoing uCAG (n = 1840, 30-day mortality: 9.0% vs 0.4%, p < 0.001). Long-term survival was significantly decreased in patients undergoing uCAG in both unadjusted (hazard ratio [HR] 2.20, 95% CI 1.30-3.73), and EuroSCORE-, age-, and sex-adjusted models (HR uCAG 2.03, 95% CI 1.16-3.56). CONCLUSIONS: Unplanned postoperative CAG is performed in 4.1% of isolated CABG procedures, and patients in need of such urgent invasive evaluation are subjected to decreased short- and long-term survival.