Risk stratification of non-cardiac surgeries in adult congenital heart disease

Abstract Background Adults with congenital heart disease (ACHD) face multiple surgeries throughout their lifetime. Data on the specific risk of undergoing non-cardiac surgery and impact of severity of ACHD on outcome are limited. We aimed to assess frequency and outcome of non-cardiac surgery and to identify ACHD patients specifically at risk. Methods Based on data including all hospital admissions in Germany from 2011 to 2018, we identified all ACHD cases that were admitted for non-cardiac surgery. Non-cardiac surgery was categorized in low-, medium and high-risk based on a clinically implemented risk score validated for non-congenital cardiac patients. The analyzed data contained information on patient demographics, diagnoses, in-hospital complications, and mortality. The primary endpoints of the study were major adverse cardiovascular events (MACE), major infection, major bleeding, thromboembolism and in-hospital death. Outcomes of ACHD were compared to a propensity score matched cohort of non-ACHD. Results Overall, 13,041 ACHD inpatient cases were included in the analysis (simple n=9,333 (72%), moderate n=2,741 (21%), and complex heart defects n=966 (7%)). 23.0% simple ACHD underwent low-risk surgery, whilst 31.1% were intermediate and 45.0% high-risk procedures. In the medium complexity ACHD cohort, 35.8% received low-risk, 42.3% intermediate risk and 21.8% high-risk surgery. In complex ACHD, 42.4% underwent low-risk, 41.2% intermediate risk and 16.4% high-risk surgery. Simple ACHD more frequently presented with typical cardiovascular risk factors such as dyslipidemia, arterial hypertension and diabetes mellitus compared to moderately and severely complex ACHD at time of non-cardiac surgery (p<0.001 for all). Compared to a propensity score matched cohort of non-ACHD, congenital cardiac patients more often met the endpoints with an increasing frequency depending on complexity of disease and pre-defined risk of surgery. After adjustment on multivariable logistic regression analysis, moderate and severe complexity of the congenital cardiac defect was associated with an adverse outcome. Risk for death was increased in moderately complex (OR 1.44, 95% CI 1.15 - 1.81, p=0.001) and severely complex ACHD (OR 2.28, 95% CI 1.63 - 3.20, p<0.001) compared to non-ACHD. Compared to low-risk surgeries, patients were at increased risk for death when undergoing mid- (OR 7.66, 95% CI 5.18 - 11.34, p<0.001) or high-risk surgeries (OR 8.03, 95% CI 5.42 - 11.90, p<0.001). Conclusions ACHD patients are at increased risk of adverse complications when undergoing non-cardiac surgery. Risk for adverse outcomes increased with complexity of disease and was generally higher than in non-ACHD individuals. The presented data show that surgical risk classifications implemented for non-congenital cardiac patients were also associated with a much higher adverse outcome in cases undergoing high- versus low-risk procedures.