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. (February 2016)

• Record Type: Journal Article
• Authors: Valenti, Valentina; Hartaigh, Bríain ó; Cho, Iksung; Schulman-Marcus, Joshua; Gransar, Heidi; Heo, Ran; Truong, Quynh A.; Shaw, Leslee J.; Knapper, Joseph; Kelkar, Anita A.; Sciarretta, Sebastiano; Chang, Hyuk-Jae; Callister, Tracy Q.; Min, James K.
• Is Part Of: Circulation. Volume 9:Number 2(2016)
• Publication Date: 2016-02
• Subjects: calcium score -- computed tomography -- coronary artery calcium -- diabetes mellitus -- mortality -- prognosis; Cardiovascular system -- Imaging -- Periodicals; Heart -- Imaging -- Periodicals; 616.1075405
• DOI: 10.1161/CIRCIMAGING.115.003528
• Languages: English
• ISSNs: 1941-9651

Abstract

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 diabetic compared with nondiabetic individuals. Methods and Results—: Nine thousand seven hundred and fifteen asymptomatic individuals undergoing CAC scoring were followed for a median (interquartile range) of 14.7 (13.9–15.6) years. The incidence density rate and hazard ratios with 95% confidence intervals were used to calculate all-cause mortality. Incremental prognostic utility of CAC was evaluated using the area under the receiver operator characteristic curve and net reclassification improvement. 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 nondiabetic individuals for the first 5 years ( P >0.05), with a nonlinear 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% confidence interval =3.74–5.76) and 3.41 (95% confidence interval =2.22–5.22) for nondiabetic and diabetic individuals, respectively. The presence of CAC improved discrimination (area under the receiver operator characteristic curve range: 0.73–0.74; P <0.01) and reclassification (category-free net reclassification improvement range: 0.53–0.50; P <0.001) beyond conventional risk factors in nondiabetic and diabetic individuals, respectively. Conclusions—: CAC=0 is associated with a favorable 5-year prognosis for asymptomatic diabetic and nondiabetic individuals. After 5 years, the risk of mortality increases significantly for diabetic individuals even in the presence of a baseline CAC=0.