  Citation: Viladés-Medel, D.; Dégano, I.R.; Subirana, I.; Descalzo, M.; Padilla, M.; Mundet, X.; Carreras Costa, F.; Alomar Serrallach, X.; Camps, A.; Elosua, R.; et al. Usefulness of Cardiac Computed Tomography in Coronary Risk Prediction: A Five-Year Follow-Up of the SPICA Study (Secure Prevention with Imaging of the Coronary Arteries). J. Clin. Med. 2022, 11, 533. https://doi.org/10.3390/ jcm11030533 Academic Editor: Jonathan Townend Received: 30 November 2021 Accepted: 19 January 2022 Published: 21 January 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). Journal of Clinical Medicine Article Usefulness of Cardiac Computed Tomography in Coronary Risk Prediction: A Five-Year Follow-Up of the SPICA Study (Secure Prevention with Imaging of the Coronary Arteries) David Viladés-Medel 1, * , Irene R. Dégano 2,3,4 , Isaac Subirana 2,3 , Martin Descalzo 1 , Mireia Padilla 1 , Xavier Mundet 5,6 , Francesc Carreras Costa 1,2,3 , Xavier Alomar Serrallach 7 , Anna Camps 2,3 , Roberto Elosua 2,3,4 , Jaume Marrugat 2,3 and Rubén Leta Petracca 1 1 Cardiac Imaging Unit, Cardiology Department, Hospital de la Santa Creu i Sant Pau, Universitat Autónoma de Barcelona (UAB), 08193 Barcelona, Spain; mdescalzo@santpau.cat (M.D.); mpadillal@santpau.cat (M.P.); FCarreras@santpau.cat (F.C.C.); rleta@santpau.cat (R.L.P.) 2 CIBER de Enfermedades Cardio-Vasculares (CIBERCV), Instituto de Salud Carlos III (ISCIII), 28029 Madrid, Spain; irene.roman@umedicina.cat (I.R.D.); isubirana@imim.es (I.S.); acamps@imim.es (A.C.); relosua@imim.es (R.E.); jaume@imim.es (J.M.) 3 REGICOR Study Group, IMIM (Hospital del Mar Medical Research Institute), 08003 Barcelona, Spain 4 Faculty of Medicine, University of Vic-Central University of Catalonia (UVic-UCC), 08500 Vic, Spain 5 University Public Health Center El Carmel, Department of Medicine, Universitat Autonoma de Barcelona (UAB), 08193 Barcelona, Spain; 16274xmt@comb.cat 6 Barcelona Ciutat Research Support Unit-IDIAP Jordi Gol, redIAPP, 08007 Barcelona, Spain 7 Radiology Department, Clínica Creu Blanca, 08034 Barcelona, Spain; xalomar@creublanca.es * Correspondence: dvilades@santpau.cat Abstract: Accurate identification of individuals at high coronary risk would reduce acute coronary syndrome incidence and morbi-mortality. We analyzed the effect on coronary risk prediction of adding coronary artery calcification (CAC) and Segment Involvement Score (SIS) to cardiovascular risk factors. This was a prospective cohort study of asymptomatic patients recruited between 2013–2017. All participants underwent a coronary computed tomography angiography to determine CAC and SIS. The cohort was followed-up for a composite endpoint of myocardial infarction, coronary angiography and/or revascularization (median = five years). Discrimination and reclassification of the REGICOR function with CAC/SIS were examined with the Sommer’s D index and with the Net reclassification index (NRI). Nine of the 251 individuals included had an event. Of the included participants, 94 had a CAC = 0 and 85 a SIS = 0, none of them had an event. The addition of SIS or of SIS and CAC to the REGICOR risk function significantly increased the discrimination capacity from 0.74 to 0.89. Reclassification improved significantly when SIS or both scores were included. CAC and SIS were associated with five-year coronary event incidence, independently of cardiovascular risk factors. Discrimination and reclassification of the REGICOR risk function were significantly improved by both indexes, but SIS overrode the effect of CAC. Keywords: coronary artery disease risk; cardiac computed tomography; coronary artery calcium; primary prevention 1. Introduction In the next decades, an increasing incidence of acute coronary syndrome (ACS) is expected in Spain, mainly due to the aging of the population. Up to 60% of all ACS cases will occur in the elderly population by 2049 [1]. The most cost-effective way to control the significant health and mortality burden of cardiovascular disease (CVD) is to reduce its incidence by identifying high-risk populations. To improve the sensitivity and specificity of identifying high-risk individuals, imaging biomarkers could be included in CVD or coronary artery disease (CAD) risk functions [2,3]. J. Clin. Med. 2022, 11, 533. https://doi.org/10.3390/jcm11030533 https://www.mdpi.com/journal/jcm