The goal of this study was to determine the long-term prognostic value of coronary computed tomography angiography (CTA) among patients with diabetes mellitus (DM) compared with nondiabetic subjects.
Background
The long-term prognostic value of coronary CTA in patients with DM is not well established.
Methods
Patients enrolled in the CONFIRM (Coronary CT Angiography Evaluation for Clinical Outcomes: An International Multicenter) registry with 5-year follow-up data were identified. The extent and severity of coronary artery disease (CAD) were analyzed at baseline coronary CTA and in relation to outcomes between diabetic and nondiabetic patients. CAD according to coronary CTA was defined as none (0% stenosis), nonobstructive (1% to 49% stenosis), or obstructive (≥50% stenosis). Time to death (and in a subgroup, time to major adverse cardiovascular event) was estimated by using multivariable Cox proportional hazards models.
Results
A total of 1,823 patients were identified as having DM with 5-year clinical follow-up and were propensity-matched to 1,823 patients without DM (mean age 61.8 ± 10.9 years; 54.4% male). Patients with DM did not exhibit a heightened risk of death compared with the propensity-matched nondiabetic subjects in the absence of CAD on coronary CTA (risk-adjusted hazard ratio [HR] of DM: 1.32; 95% confidence interval [CI]: 0.78 to 2.24; p = 0.296). Patients with DM were at increased risk of dying compared with nondiabetic subjects in the setting of nonobstructive CAD (in the propensity-matched cohort: HR, 2.10; 95% CI: 1.43 to 3.09; p < 0.001) with a mortality risk greater than nondiabetic subjects with obstructive disease (p < 0.001). In a risk-adjusted hazard analysis among patients with DM, both per-patient obstructive CAD and nonobstructive CAD conferred an increase in all-cause mortality risk compared with patients without atherosclerosis on coronary CTA (nonobstructive disease—HR: 2.07; 95% CI: 1.33 to 3.24; p = 0.001; obstructive disease—HR: 2.22; 95% CI: 1.47 to 3.36; p < 0.001).
Conclusions
Among patients with DM, nonobstructive and obstructive CAD according to coronary CTA were associated with higher rates of all-cause mortality and major adverse cardiovascular events at 5 years, and this risk was significantly higher than in nondiabetic subjects. Importantly, patients with DM without CAD according to coronary CTA were at a risk comparable to that of nondiabetic subjects.
Dr. Blanke has served as a consultant (not related to this manuscript) for Edwards Lifesciences, Tendyne, Circle Imaging, Neovasc, and HeartFlow. Dr. Budoff has received grants from the National Institutes of Health and General Electric. Dr. Cademartiri has served as a consultant for Siemens and Guerbet. Dr. Min has served as a consultant for Abbott Vascular, HeartFlow, NeoGraft Technologies, MyoKardia, and CardioDx; has been a member of the Scientific Advisory Board for Arineta; reports ownership in MDDX and Autoplaq; has a research agreement with GE Healthcare; and has received grants from the National Institutes of Health/National Heart, Lung, and Blood Institute (R01HL111141, R01HL115150, R01HL118019, and U01HL105907) and NPRP09-370-3-089. Dr. Chow has received research support from GE Healthcare and TeraRecon. Dr. Leipsic has served as a consultant for GE Healthcare, Samsung, and Philips. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose. Khurram Nasir, MD, served as Guest Editor for this article.
