Abstract 10982: A Novel Index of Coronary Artery Calcium Derived From Preoperative Non-Gated Chest Computed Tomography Correlates With Traditional Estimates of Perioperative Risk

Abstract

Introduction: Cardiovascular events are feared complications of non-cardiac surgery. Prior studies demonstrate associations between coronary artery calcium (CAC) from ECG-gated computed tomography (CT) imaging and perioperative major adverse cardiac events. We sought to evaluate correlations between an index of CAC severity from preoperative non-gated CT imaging and traditional estimates of perioperative risk. Methods We identified consecutive adults age ≥45 years who underwent in-hospital, major non-cardiac surgery across a large urban health system between 2016 and 2020 and had non-gated (contrast or non-contrast) chest CT imaging performed within 1 year prior to surgery. Patients with prior coronary revascularization or heart valve surgery were excluded. CAC severity in each coronary artery was assessed and graded from absent to severe using a 0-3 scale by physicians blinded to clinical data. An index of CAC was computed as the sum of the scores for each coronary artery. The Revised Cardiac Risk Index (RCRI) was determined for each patient. Correlations between the CAC index and RCRI were assessed using Spearman Correlation Coefficient (𝜌;). Results A total of 2,560 patients met inclusion criteria - mean age 68.1 ± 12.3 years, 49.8% female, 60% white (Figure 1A). The median pre-operative RCRI score was 1 [IQR 0-1, range 0-6] (Figure 1B). A majority of patients (64.3%) had non-contrast chest CT imaging. The median CAC index was 1 [IQR 0-3, range 0-9] (Figure 1C). A correlation between the CAC index and RCRI (Coefficient (𝜌;): 0.209, p<0.001) was observed, with stepwise increases in the CAC index when stratified by pre-operative RCRI (Figure 1D). Conclusions A pragmatic, novel index of CAC derived from existing non-gated chest CT imaging correlates with pre-operative RCRI. As the RCRI is a validated preoperative risk stratification tool, this finding demonstrates the potential to leverage pre-existing, non-gated CT imaging to inform preoperative risk assessment.