Prevalence and prognosis of left ventricular systolic dysfunction in asymptomatic diabetic patients without known coronary artery disease referred for stress single-photon emission computed tomography and assessment of left ventricular function

BackgroundThe prevalence and prognosis of reduced left ventricular ejection fraction (LVEF) in asymptomatic diabetic patients without known coronary artery disease (CAD) are not known.MethodsWe examined 1046 asymptomatic diabetic patients (age 60 ± 13 years, 69% male) without known CAD referred to a tertiary referral center for stress single-photon emission computed tomography (SPECT) and assessment of LVEF. Patients were stratified according to the presence of normal LVEF (≥50%), mildly reduced LVEF (35%-49%), or moderately/severely reduced LVEF (<35%). Single-photon emission computed tomographic images were classified as low, intermediate, or high risk based on the summed stress score (normal = 56). The mean follow-up was 5.3 ± 3.3 years.ResultsThe prevalence of reduced LVEF was 16.7% (n = 175, mean LVEF 40.0% ± 7.7%). This group was older (63 ± 11 vs 59 ± 14 years, P = .005), had more peripheral arterial disease (45% vs 29%, P < .001), and had a higher prevalence of electrocardiographic Q waves (21% vs 9%, P < .001) than the group without reduced LVEF. Mean summed stress (44.8 ± 9.8 vs 51.7 ± 6.3, P < .001), summed reversibility (4.7 ± 5.0 vs 2.9 ± 4.5, P < .001), and summed rest scores (49.4 ± 7.2 vs 54.6 ± 3.1, P < .001) were significantly more abnormal in the reduced LVEF group. High-risk summed stress score was significantly more common in the reduced LVEF group (46% vs 16%, P < .001). Survival was significantly lower in patients with any reduction in LVEF compared with those without reduced LVEF (10-year survival, 29% vs 57%, P < .0001). By multivariate analysis, reduced LVEF was independently associated with increased mortality (adjusted χ2 = 6.26, P = .01).ConclusionsIn this population of asymptomatic diabetic patients without known CAD referred for stress SPECT, 1 in 6 patients had reduced LVEF. Most of these patients have intermediate-/high-risk SPECT scans. The annual mortality rates of the groups with and without reduced LVEF were 7% and 4%, respectively.