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.

Background: The prevalence and prognosis of reduced left ventricular ejection fraction (LVEF) in asymptomatic diabetic patients without known coronary artery disease (CAD) are not known.
Methods: We 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 (> or = 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.
Results: The 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 chi2 = 6.26, P = .01).
Conclusions: In 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.