Absence of Coronary Artery Calcium Identifies Asymptomatic Diabetic Individuals at Low Near-Term But Not Long-Term Risk of Mortality A 15-Year Follow-Up Study of 9715 Patients

• Type of Material: Article
• Authors: Valentina Valenti, NewYork-Presbyterian Hospital; Bríain ó Hartaigh, NewYork-Presbyterian Hospital; Iksung Cho, NewYork-Presbyterian Hospital; Joshua Schulman-Marcus, Weill Cornell Medical College; Heidi Gransar, Cedars-Sinai Medical Center; Ran Heo, NewYork-Presbyterian Hospital; Quynh Truong, NewYork-Presbyterian Hospital; Leslee Shaw, Emory University; Joseph Knapper, Emory University; Anita A. Kelkar, Emory University; Sebastiano Sciarretta, IRCCS Neuromed; Hyuk-Jae Chang, Yonsei University; Tracy Q. Callister, Tennessee Heart and Vascular Institute; James K. Min, NewYork-Presbyterian Hospital
• Language: English
• Date: 2016-02-01
• Publisher: American Heart Association
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2016 American Heart Association, Inc.
• Final Published Version (URL): http://dx.doi.org/10.1161/CIRCIMAGING.115.003528
• Title of Journal or Parent Work: Circulation: Cardiovascular Imaging
• Volume: 9
• Issue: 2
• Start Page: e003528
• End Page: e003528
• Grant/Funding Information: This study was supported in part by a grant from the National Institutes of Health (R01HL115150 and R01HL118019). This study was also funded, in part, by a generous gift from the Dalio Institute of Cardiovascular Imaging and the Michael Wolk Foundation. Dr. Truong was supported by the NIH (K23HL098370 and L30HL093896). Dr. Hyuk-Jae Chang was supported by Leading Foreign Research Institute Recruitment Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (MSIP) (2012027176).
• Keywords: Life Sciences & Biomedicine; calcium score; prognosis; computed tomography; coronary artery calcium; Radiology, Nuclear Medicine & Medical Imaging; diabetes mellitus; Cardiac & Cardiovascular Systems; mortality; Science & Technology
• Research Categories: Health Sciences, Radiology; Health Sciences, Medicine and Surgery

Abstract

Background: Data regarding coronary artery calcification (CAC) prognosis in diabetic individuals are limited to 5-years follow-up. We investigated the long-term risk stratification of CAC among diabetics, compared to non-diabetic individuals. Methods and Results: 9715 asymptomatic individuals undergoing CAC scoring were followed for a median (IQR) of 14.7 (13.9–15.6) years The incidence density rate and hazard ratios (HR) with 95% confidence intervals (95%CI) were used to calculate all-cause mortality. Incremental prognostic utility of CAC was evaluated using the area under the receiver operator characteristic curve (AUC) and net reclassification improvement (NRI). Diabetics (54.7±10.8 years; 59.4% male) comprised 8.3% of the cohort (n=810), of which 188 (23.2%) died. For CAC=0, the rate of mortality was similar between diabetic and non-diabetic individuals for the first 5 years (p>0.05), with a non-linear increased risk of mortality for diabetics after 5 years (p<0.05). The adjusted risk of death for those in the highest (CAC>400) versus the lowest (CAC=0) category of CAC increased by a hazards of 4.64 (95%CI=3.74–5.76) and 3.41 (95%CI=2.22–5.22) for non-diabetic and diabetic individuals, respectively. The presence of CAC improved discrimination (AUC range: 0.73–0.74, P<0.01) and reclassification (category-free NRI range: 0.53–0.50, P<0.001) beyond conventional risk factors in non-diabetic and diabetic respectively. Conclusions: CAC=0 is associated with a favorable 5-year prognosis for asymptomatic diabetic and non-diabetic individuals. After 5 years, the risk of mortality increases significantly for diabetic individuals even in the presence of a baseline CAC=0.