Aim: The aim of this study was to evaluate added value of coronary artery calcium score (CAC) measurement as an adjunct to cardiac gated SPECT for risk stratification in population of patients with diabetes mellitus (DM) and/or chronic renal failure on hemodialysis (CHRF-HD).
Methods: Retrospective analysis of 67 patients, who were referred for stress gated myocardial perfusion SPECT and CAC. Characteristics of study population: 40 men, mean age 59 +/- 12 years, DM (n = 28), CHRF-HD (n = 22), DM and CHRF-HD simultaneously (n = 17). Perfusion summed stress and different scores (SSS, SDS), the left ventricle ejection fraction (LVEF) and enddiastolic/endsystolic volumes (EDV/ESV) were automatically calculated using 4D-MSPECT software. The hard cardiac event was defined as sudden cardiac death or myocardial infarction (MI); angina or other symptoms requiring coronary revascularization were also calculated.
Results: During the average period of 18 +/- 10 months, we registered 8 cardiac deaths, 4 nonfatal MI and 7 patients underwent revascularization. In the subgroup of 19 patients with cardiac events, the observed parameters were significantly worse concerning perfusion (SSS 9 +/- 11 vs 2 +/- 3 and SDS 6 +/- 9 vs 1 +/- 2, P < 0.05), the left ventricle function (stress LVEF 53% +/- 13% vs 59% +/- 13%, rest LVEF 55% +/- 14% vs 59% +/- 12%, stress EDV/ESV 144 ml/71 ml vs 128 ml/59 ml, P < 0.05), and CAC score (1 965 +/- 1 772 vs 387 +/- 740, P < 0.05) in comparison with patients without cardiac event. In patients without a reversible perfusion abnormality (SDS < 2), we observed lower annual hard event rate (8% vs 19.6%, P < 0.05) and revascularization procedures (4% vs 19.6%, P < 0.05) in comparison with patients with SDS > or = 2. In patients with or without reversible defects, we registered significantly higher annual hard event rate in the setting of post-stress worsening of the LVEF > 5% and/or severe CAC score > or = 709 (23.8% vs 1.9% in patients with SDS < 2, and 26.7% vs 9.5% in patients with SDS > or = 2, P < 0.05).
Conclusion: The findings of highly elevated CAC score as well as the post-stress left ventricle stunning enable further risk stratification in patients with or without reversible perfusion abnormalities.