Effect of Screening for Coronary Artery Disease Using CT Angiography on Mortality and Cardiac Events in High-Risk Patients With Diabetes: The FACTOR-64 Randomized Clinical Trial | Journal Scan

Study Questions:

Does routine screening for coronary artery disease (CAD) by coronary computed tomography angiography (CCTA) of patients with type 1 or 2 diabetes at high cardiac risk reduce the risk of death and nonfatal coronary events?

Methods:

The FACTOR-64 study was a randomized clinical trial in which 900 patients with ≥ 3- to 5-year history of type 1 or 2 diabetes and without symptoms of CAD were recruited from 45 clinics and practices of a single health system (Intermountain Healthcare, Utah), enrolled at a single-site coordinating center, and randomly assigned to CAD screening with CCTA (n = 452) or to standard national guidelines-based optimal diabetes care (n = 448) (targets: glycated hemoglobin level <7.0%, low-density lipoprotein cholesterol level <100 mg/dl, systolic blood pressure <130 mm Hg). Based on CCTA findings, standard therapy was recommended versus aggressive therapy (targets: glycated hemoglobin level <6.0%, low-density lipoprotein cholesterol level <70 mg/dl, high-density lipoprotein cholesterol level >50 mg/dl [women] or >40 mg/dl [men], triglycerides level <150 mg/dl, systolic blood pressure <120 mm Hg) versus aggressive therapy with invasive coronary angiography. Enrollment occurred between July 2007 and May 2013, and follow-up extended to August 2014. The primary outcome was a composite of all-cause mortality, nonfatal myocardial infarction (MI), or unstable angina requiring hospitalization; the secondary outcome was ischemic major adverse cardiovascular events (MACE) (composite of CAD death, nonfatal MI, or unstable angina).

Results:

At a mean follow-up of 4.0 ± 1.7 years, the primary outcome event rates were not significantly different between the CCTA and the control groups (6.2% [28 events] vs. 7.6% [34 events]; hazard ratio, 0.80; 95% confidence interval, 0.49-1.32; p = 0.38). The incidence of the composite secondary endpoint of ischemic MACE also did not differ between groups (4.4% [20 events] vs. 3.8% [17 events]; hazard ratio, 1.15; 95% confidence interval, 0.60-2.19; p = 0.68).

Conclusions:

Among asymptomatic patients with type 1 or 2 diabetes, the use of CCTA to screen for CAD did not reduce the composite rate of all-cause mortality, nonfatal MI, or unstable angina requiring hospitalization at 4 years. These findings do not support CCTA screening in this population.

Perspective:

CAD is a major cause of morbidity and mortality among patients with diabetes mellitus, and patients often are asymptomatic prior to morbid and mortal cardiac events. This study demonstrated that routine screening with coronary CCTA does not lower patient risk. The observed low event rates in both groups likely can be attributed to aggressive medical management in terms of risk factor modification. As with other published studies (Young LH, et al., JAMA 2009;30:1547-55), routine screening for CAD, even among patients at high risk, is not supported by improved outcomes.

Clinical Topics: Diabetes and Cardiometabolic Disease, Dyslipidemia, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Atherosclerotic Disease (CAD/PAD), Hypertriglyceridemia, Lipid Metabolism, Interventions and Coronary Artery Disease, Interventions and Imaging, Angiography, Nuclear Imaging

Keywords: Angina, Unstable, Blood Pressure, Coronary Angiography, Coronary Artery Disease, Diabetes Mellitus, Hemoglobin A, Glycosylated, Hospitalization, Lipoproteins, HDL, Lipoproteins, LDL, Myocardial Infarction, Risk, Tomography, Triglycerides, Utah


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