title: Myocardial perfusion imaging and risk classification for coronary heart disease in diabetic patients. The IDIS study: a prospective, multicentre trial.
abstract: OBJECTIVE
  To determine whether stress-rest myocardial perfusion single-photon emission (MPS) computed tomography improves coronary heart disease (CHD) risk classification in diabetic patients.
  
  
  METHODS
  In 822 consecutive diabetic patients, risk estimates for a CHD event were categorized as 0% to <3%, 3% to <5%, and ≥5% per year using Cox proportional hazards models. Model 1 used traditional CHD risk factors and electrocardiography (ECG) stress test data and model 2 used these variables plus MPS imaging data. We calculated the net reclassification improvement (NRI) and compared the distribution of risk using model 2 vs. model 1. CHD death, myocardial infarction and unstable angina requiring coronary revascularization were the outcome measures.
  
  
  RESULTS
  During follow-up (58 ± 11 months), 148 events occurred. Model 2 improved risk prediction compared to model 1 (NRI 0.25, 95% confidence interval, CI, 0.15-0.34; p < 0.001). Overall, 301 patients were reclassified to a higher risk category, with an event rate of 28%, and 26 to a lower risk category, with an event rate of 15%. Among patients at 3% to <5% risk, 53% were reclassified at higher risk and 25% at lower risk (NRI 0.42, 95% CI 0.07-0.76; p < 0.05). The cost per NRI was $880.80 for MPS imaging as compared to an outpatient visit with an ECG stress test.
  
  
  CONCLUSIONS
  The addition of MPS imaging data to a prediction model based on traditional risk factors and ECG stress test data significantly improved CHD risk classification in patients with diabetes.
authors: Department of Biomorphological and Functional Sciences, University Federico II, Napoli, Italy.
authors: Wanda
authors: W
authors: Acampa
authors: Mario
authors: M
authors: Petretta
authors: Laura
authors: L
authors: Evangelista
authors: Stefania
authors: S
authors: Daniele
authors: Evgjeni
authors: E
authors: Xhoxhi
authors: Maria Luisa
authors: ML
authors: De Rimini
authors: Corrado
authors: C
authors: Cittanti
authors: Filippo
authors: F
authors: Marranzano
authors: Marco
authors: M
authors: Spadafora
authors: Sergio
authors: S
authors: Baldari
authors: Luigi
authors: L
authors: Mansi
authors: Alberto
authors: A
authors: Cuocolo
mesh_terms: D015331:Cohort Studies; D003327:Coronary Disease / Q000175:diagnosis* / Q000503:physiopathology; D003362:Cost-Benefit Analysis; D048909:Diabetes Complications / Q000175:diagnosis* / Q000503:physiopathology; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000191:economics / Q000379:methods*; D018570:Risk Assessment; D012307:Risk Factors; D013312:Stress, Physiological; D016019:Survival Analysis; D013997:Time Factors