Effect of age and gender on pre-operative cardiovascular risk assessment

BACKGROUND: The AUB-HAS2 Cardiovascular Risk Index is a recently published tool for pre-operative cardiovascular evaluation. It is based on six data elements: history of heart disease, symptoms of angina or dyspnea, age ≥ 75 years, hemoglobin < 12 mg/dl, vascular surgery, and emergency surgery. The objective of this study is to study the effect of age and gender on the performance of the AUB-HAS2 Index in pre-operative cardiovascular risk assessment. METHODS: The study population consisted of 1,167,414 non-cardiac surgeries registered in the ACS NSQIP database. The population was stratified by age (≥ 40 and < 40 years old) and by gender (men and women). Each patient was given an AUB-HAS2 score of 0, 1, 2, 3, or > 3 based on the number of data elements s/he has. The outcome measure was all-cause mortality, myocardial infarction (MI), or stroke at 30 days after surgery. RESULTS: The overall 30-day event rate was higher in patients ≥ 40 years compared to those < 40 years (2.5% vs 0.3%, P < 0.0001) and in men compared to women (2.7% vs 1.8%, P < 0.0001). In both age and gender subgroups, there was a gradual and significant increase in the outcome measure (death, MI, or stroke) as the AUB-HAS2 score increased: from ≤ 0.5% in those with a score of 0 to more than 15% in those with a score > 3 (P < 0.0001). The AUB-HAS2 Index was able to stratify risk in all subgroups into low, intermediate, and high (P < 0.0001). Receiver operating characteristic curves showed the AUB-HAS2 Index has very good discriminatory power in both age (area under the curve (AUC) of 0.81 and 0.78) and gender (AUCs of 0.79 and 0.84) subgroups. CONCLUSION: This study extends the validation of the newly derived AUB-HAS2 Cardiovascular Risk Index to different age and gender subgroups with very good discriminative power.