Risk rate of major adverse cardiovascular event and charlson comorbidity index in patients undergoing coronary CTA with symptoms suggesting chronic coronary syndrome compared to a reference population
Authors: Nissen L , Winther S , Soeby J H S , Boetcher M 
Published: November 2023

Abstract

Background
Approximately 12,000 patients annually undergo a coronary computed tomography angiography (CTA) due to symptoms suggestive of chronic coronary syndrome (CCS) in the Western part of Denmark (3.2 million inhabitants) (1).
The purpose of this study was to examine the burden of comorbidity and the risk of a major adverse cardiovascular events (MACE)(2) in a large population of patients investigated using coronary CTA compared to a reference population.

Methods
Patients undergoing first-time coronary CTA from 2008 to October 2022 with symptoms suggestive of CCS were included from the Western Denmark Heart Registry (WDHR). A positive coronary CTA was defined as having a diameter stenosis of ≥ 50% stenosis(1). A reference population was generated matching the CTA population 1:5 based on birth year, gender and municipality using data from national registries.
Results are presented in 4 groups; as patients with a positive coronary CTA and their reference population and patients with a negative coronary CTA and their reference population.
Information on MACE was obtained from the national patient registry as a composite of acute myocardial infarct (AMI), stroke, revascularization, cardiovascular mortality and all-cause mortality and calculated as risk rates per 1000 persons one year after the coronary CTA examination. A Charlson comorbidity index (CCI)(3) was also calculated.

Results
From the WDHR 94,207 patients, (Mean age 58±11, 48% men) with a first-time coronary CTA on indication CCS were included. Among all conducted coronary CTA scans 18,290 (19.4%) were positive (&gt;50% stenosis). In the analyses of CCI 90,074 patients from the WDHR were matched with 450,345 controls. Patients with both a positive and negative coronary CTA examination had significantly higher CCI than their matching reference population (Table 1).
In table 2 risk rates of a MACE are presented after one year following the coronary CTA examination; in this analysis 53,610 patients from the WDHR were matched with 268,040 controls. The risk of AMI was higher among both patients with and without suspected stenosis compared to their respective reference population., However, the risk of all-cause mortality was higher in both the reference populations. The risk rate of revascularization after a positive coronary CTA was, as could be expected, much higher compared to all other groups as this was a result of the examination.

Conclusion
In this large study of patients referred to coronary CTA we found a higher incidence of AMI and revascularization in both patients with and with suspected stenoses compared to a reference population. However, we also found a lower mortality rate in both groups compared to a reference population. This could indicate a more well treated population, but a direct causality cannot be concluded from this study and further research is needed to better understand this association.Charlson comorbidity indexMACE events