Letter to the Editor Long term prognostic value of Coronary Computed Tomography Angiography in suspected coronary artery disease: A 62 month median follow-up study Mouaz H. Al-Mallah a,b,c, ⁎ ,1 , Waqas Qureshi d , Milan Pantelic a , Khaled Nour a a 2799 W. Grand Blvd., Henry Ford Hospital/Wayne State University, Detroit, MI, 48202 USA b 540 E Canfield St., Wayne State University, Detroit, MI 48201 USA c King Abdul-Aziz Cardiac Center, National Guard Health Affairs, Riyadh, Saudi Arabia d Wake Forest University School of Medicine, Winston Salem, NC 27157, USA article info Article history: Received 26 June 2014 Accepted 27 July 2014 Available online 4 August 2014 Keywords: All-cause mortality Outcomes Coronary Computed Tomography Angiography In recent years, Coronary Computed Tomography Angiography (CCTA) has emerged as a novel tool for the non-invasive detection of CAD [1,2]. Its prognostic value has been well demonstrated over short follow-up duration (median follow-up duration of nearly two years) [3–5]. However, there is limited data regarding the long term prognostic value of CCTA [6]. We evaluated five year prognosis of normal or non- obstructive CAD on CCTA. We also determined the prognostic value of plaque burden and plaque morphology based on their calcification pattern. Consecutive patients (n = 454) without known CAD who underwent CCTA at a single tertiary care center between 2006 and 2008 were included. Patients with known CAD, systolic left ventricular failure and renal disease were excluded. The study was approved by the Institutional Review Board of the study hospital. All CCTA scans were performed with a 64-multidetector row scanner (General Electric, Milwaukee, WI) using retrospective gating. Each CCTA was interpreted by a cardiologist and a radiologist on a 3-dimensional image analysis International Journal of Cardiology 176 (2014) 1244–1246 Abbreviations: CCTA, Coronary Computed Tomography Angiography; CAD, coronary artery disease; SCCT, Society of Cardiovascular Computed Tomography; CABG, Coronary Artery Bypass Grafting; PCI, Percutaneous Coronary Intervention; HR, hazard ratio. ⁎ Corresponding author at: Cardiac Imaging, King Abdul-Aziz Cardiac Center, King Abdul-Aziz Medical City (Riyadh), National Guard Health Affairs, Department Mail Code: 1413, P.O. Box 22490, Riyadh 11426, Kingdom of Saudi Arabia. Tel.: +966 118011111x16594; fax: +966 118011111x16700. 1 Associate Professor of Medicine, Wayne State University, Detroit, MI, USA. workstation in the same setting. Coronary segments were visually scored for the presence of coronary plaque using a 16-segment coronary artery model based on Society of Cardiovascular Computed Tomogra- phy (SCCT) guidelines [7]. Plaque Stenosis severity was visually classi- fied into three groups based on 1) no CAD defined as no coronary plaque, 2) non-obstructive CAD defined as luminal stenosis between 1 and 49% and 3) obstructive CAD was defined as luminal stenosis ≥50%. A ≥50% stenosis in the LM was considered to be two-vessel dis- ease in the LAD and LCx. In each coronary artery segment, plaques were classified as non-calcified, mixed, or calcified by visual inspection. Non- calcified plaque was defined as a tissue structure N 1 mm [1] that could be clearly discriminated from the vessel lumen and surrounding tissue, with a density below the contrast-enhanced blood pool. Plaques meet- ing this definition and in addition showing calcified areas of any extent were classified as mixed plaques. Coronary artery plaque scores were calculated for overall plaque burden by extent and severity of CAD using a segment stenosis score (SSS) and segment-involvement score (SIS). As a measure of CAD distribution, SIS was calculated based on just the presence of plaque within a segment, irrespective of the degree of luminal stenosis within each segment (min = 0; max = 16) [4]. In addition, calcified segment involvement score, mixed segment involve- ment score, and non-calcified segment involvement score (per segment involved) were calculated. SSS was used as a measure of overall coro- nary artery plaque extent. Each individual coronary segment was grad- ed as having no to severe plaque (scores from 0 to 4) based on the extent of luminal stenosis (0 = none, 1 = 1%–25%, 2 = 26–49%, 3 = 50–74% and 4 ≥ 75%). Then the sum scores of all 16 individual segments were summed to yield a total score ranging from 0 to 64. Patients were followed using extensive medical records and clinic visit evaluation search up to six years to assess major adverse cardiac events post CCTA. Major adverse cardiac events (MACE) were defined as all-cause mortality, myocardial infarction and late revascularization more than 90 days after the index CCTA using Percutaneous Coronary Intervention (PCI) or Coronary Artery Bypass Grafting (CABG). All events were adjudicated by two physicians who were blinded to the CCTA results and disagreement was resolved by consensus. http://dx.doi.org/10.1016/j.ijcard.2014.07.203 0167-5273/© 2014 Elsevier Ireland Ltd. All rights reserved. Contents lists available at ScienceDirect International Journal of Cardiology journal homepage: www.elsevier.com/locate/ijcard