Long-Term Prognostic Value of Coronary CT Angiography in Asymptomatic Type 2 Diabetes Mellitus

OBJECTIVES This study sought to evaluate the long-term prognostic value of coronary computed tomography angiography (CTA) in asymptomatic patients with type 2 diabetes mellitus. BACKGROUND There are limited data on the long-term prognostic impact of coronary CTA in asymptomatic patients with type 2 diabetes mellitus. METHODS This study analyzed clinical outcomes of 591 consecutive asymptomatic patients with type 2 diabetes mellitus who underwent coronary CTA (mean age 62.2 +/- 8.3 years and 352 men [59.6%]). A cardiac event was defined as a composite of cardiac death, nonfatal myocardial infarction, unstable angina requiring hospitalization, or late coronary revascularization. Patients were categorized into 3 groups according to severity of coronary artery disease (CAD) on coronary CTA: normal coronary arteries, nonobstructive CAD (<50%), and obstructive CAD (>= 50%). RESULTS One hundred sixty-eight patients (28.4%) had normal coronary arteries, whereas 236 (39.9%) patients had nonobstructive CAD and 187 (31.6%) had obstructive CAD. During the follow-up period (median 5.3 years [interquartile range: 4.7 to 5.8 years]), 37 cardiac events occurred in 29 patents: 10 cardiac deaths, 2 nonfatal myocardial infarctions, 8 cases of unstable angina, and 17 late coronary revascularizations. The 6-year event-free survival rates were 99.3 +/- 0.7% in patients with normal coronary arteries, 96.7 +/- 1.2% in patients with nonobstructive CAD, and 86.2 +/- 3.0% in patients with obstructive CAD (log-rank p < 0.001). CONCLUSIONS Asymptomatic patients with type 2 diabetes mellitus with normal coronary arteries or nonobstructive CAD on coronary CTA show excellent clinical outcomes over a follow-up period of more than 5 years, whereas prognosis is worse in patients with obstructive CAD. These findings suggest long-term prognostic value of coronary CTA for asymptomatic type 2 diabetes mellitus. (C) 2016 by the American College of Cardiology Foundation.